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Sample records for intracellular copper accumulation

  1. INTRACELLULAR COPPER ACCUMULATION ENHANCES THE GROWTH OF KINEOCOCCUS RADIOTOLERANS DURING CHRONIC IRRADIATION

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    Bagwell, C; Charles Milliken, C

    2007-07-24

    The actinobacteria Kineococcus radiotolerans is highly resistant to ionizing radiation, desiccation, and oxidative stress; though the underlying biochemical mechanisms are unknown. The purpose of this study was to explore a possible linkage between the uptake of transition metals and extreme resistance to ionizing radiation and oxidative stress. The effects of 6 different divalent cationic metals on growth were examined in the absence of ionizing radiation. None of the metals tested were stimulatory, though cobalt was inhibitory to growth. In contrast, copper supplementation dramatically increased cell growth during chronic irradiation. K. radiotolerans exhibited specific uptake and intracellular accumulation of copper compared to only a weak response to both iron and manganese supplementation. Copper accumulation sensitized cells to hydrogen peroxide. Acute irradiation induced DNA damage was similar between the copper-loaded culture as the age-synchronized no copper control culture, though low molecular weight DNA was more persistent during post-irradiation recovery in the Cu-loaded culture. Still, the estimated times for genome restoration differed by only 1 hr between treatments. While we cannot discount the possibility that copper fulfills an unexpectedly important biochemical role in a radioactive environment; K. radiotolerans has a high capacity for intracellular copper sequestration, and presumably efficiently coordinated oxidative stress defenses and detoxification systems, which confers cross-protection from the damaging affects ionizing radiation.

  2. Intracellular accumulation of norfloxacin in Mycobacterium smegmatis.

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    Corti, S; Chevalier, J; Cremieux, A

    1995-01-01

    To evaluate the intracellular accumulation of norfloxacin in mycobacteria, two methods were used with Mycobacterium smegmatis. A radiometric method (K. V. Cundy, C. E. Fasching, K. E. Willard, and L. R. Peterson, J. Antimicrob. Chemother. 28:491-497, 1991) was used without great modification, but the fluorometric method (P. G. S. Mortimer and L. J. V. Piddock, J. Antimicrob. Chemother. 28:639-653, 1991) was changed considerably. Indeed, adsorption of the quinolone to the bacterial surface was characterized by measuring the level of accumulation of 0 degree C. Taking into account the adsorption, the pH of the washing buffer was increased from 7.0 to 9.0 to improve the desorption of norfloxacin from the cell surface. Both the fluorometric method, with the technical improvement, and the radiometric method could be used to estimate the intracellular accumulation of norfloxacin, which resulted from the difference between the whole uptake measured at 37 degrees C and the adsorption measured at 0 degrees C. A total of 35 ng of norfloxacin per mg of cells (dry weight) penetrated into the M. smegmatis cell, and the steady state was achieved in 5 min. Use of inhibitors of the proton motive force revealed that transport of norfloxacin was energy independent. Thus, the same mechanisms of quinolone accumulation that occur in eubacteria seem to occur in mycobacteria, at least in M. smegmatis. PMID:8585727

  3. Tolerance of Oocystis nephrocytioides to copper: intracellular distribution and extracellular complexation of copper

    International Nuclear Information System (INIS)

    Soldo, Diana; Hari, Renata; Sigg, Laura; Behra, Renata

    2005-01-01

    Several mechanisms have been proposed to explain how algae can tolerate heavy metals. In order to better understand the mechanisms determining metal tolerance, we examined the interaction of copper with two strains of the copper-tolerant green algae Oocystis nephrocytioides, isolated from algal communities differing only in copper exposure. The strains were cultured in chemically-defined media containing 0.04 μM Cu total (pCu 12.4) or 2 μM Cu total (pCu 10.6). Growth, photosynthesis rate, content of chlorophyll a and b, copper accumulation, its cellular distribution and ultrastructural localization, as well as the influence of algal growth on extracellular copper complexation were determined. Both strains had comparable growth and photosynthesis rates. The cellular content of both chlorophyll a and b was reduced, by roughly the same extent, at pCu 10.6 compared to pCu 12.4. Copper titration of the media indicated the production of copper-complexing ligands by O. nephrocytioides cultured at pCu 12.4 that increased with increased algal density during cell growth. No additional ligands were detected at pCu 10.6. Copper-complexing ligands had a conditional stability constant of K = 10 13 at pH 7.3. The intracellular concentration of copper in O. nephrocytioides was 80 μM at pCu 12.4 and increased to 7.5 mM at pCu 10.6. The proportion of intracellular Cu accumulated increased from 8% of total Cu content at pCu 12.4 to 60% at pCu 10.6. By electron spectroscopic imaging, intracellular Cu was detected in the thylakoids and the pyrenoid of O. nephrocytioides cells. The results indicate that the tolerance of O. nephrocytioides to Cu is constitutive and does not need to be induced by previous exposure to Cu. We propose that accumulation and sequestration of Cu in thylakoids and, to a lesser extent, adsorption of copper to the algal cell surface represent the most important tolerance mechanism, for O. nephrocytioides

  4. Copper accumulation in senescent cells: Interplay between copper transporters and impaired autophagy

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    Shashank Masaldan

    2018-06-01

    Full Text Available Cellular senescence is characterized by irreversible growth arrest incurred through either replicative exhaustion or by pro-oncogenic cellular stressors (radioactivity, oxidative stress, oncogenic activation. The enrichment of senescent cells in tissues with age has been associated with tissue dyshomeostasis and age-related pathologies including cancers, neurodegenerative disorders (e.g. Alzheimer's, Parkinson's, etc. and metabolic disorders (e.g. diabetes. We identified copper accumulation as being a universal feature of senescent cells [mouse embryonic fibroblasts (MEF, human prostate epithelial cells and human diploid fibroblasts] in vitro. Elevated copper in senescent MEFs was accompanied by elevated levels of high-affinity copper uptake protein 1 (Ctr1, diminished levels of copper-transporting ATPase 1 (Atp7a (copper export and enhanced antioxidant defence reflected by elevated levels of glutathione (GSH, superoxide dismutase 1 (SOD1 and glutaredoxin 1 (Grx1. The levels of intracellular copper were further increased in senescent MEFs cultured in copper supplemented medium and in senescent Mottled Brindled (Mobr MEFs lacking functional Atp7a. Finally, we demonstrated that the restoration/preservation of autophagic-lysosomal degradation in senescent MEFs following rapamycin treatment correlated with attenuation of copper accumulation in these cells despite a further decrease in Atp7a levels. This study for the first time establishes a link between Atp7a and the autophagic-lysosomal pathway, and a requirement for both to effect efficient copper export. Such a connection between cellular autophagy and copper homeostasis is significant, as both have emerged as important facets of age-associated degenerative disease. Keywords: Senescence, Copper, Ageing, Homeostasis, Autophagy

  5. Copper accumulation by stickleback nests containing spiggin.

    Science.gov (United States)

    Pinho, G L L; Martins, C M G; Barber, I

    2016-07-01

    The three-spined stickleback is a ubiquitous fish of marine, brackish and freshwater ecosystems across the Northern hemisphere that presents intermediate sensitivity to copper. Male sticklebacks display a range of elaborate reproductive behaviours that include nest construction. To build the nests, each male binds nesting material together using an endogenous glycoprotein nesting glue, known as 'spiggin'. Spiggin is a cysteine-rich protein and, therefore, potentially binds heavy metals present in the environment. The aim of this study was to investigate the capacity of stickleback nests to accumulate copper from environmental sources. Newly built nests, constructed by male fish from polyester threads in laboratory aquaria, were immersed in copper solutions ranging in concentration from 21.1-626.6 μg Cu L(-1). Bundles of polyester threads from aquaria without male fish were also immersed in the same copper solutions. After immersion, nests presented higher amounts of copper than the thread bundles, indicating a higher capacity of nests to bind this metal. A significant, positive correlation between the concentration of copper in the exposure solution and in the exposed nests was identified, but there was no such relationship for thread bundles. Since both spiggin synthesis and male courtship behaviour are under the control of circulating androgens, we predicted that males with high courtship scores would produce and secrete high levels of the spiggin protein. In the present study, nests built by high courtship score males accumulated more copper than those built by low courtship score males. Considering the potential of spiggin to bind metals, the positive relationship between fish courtship and spiggin secretion seems to explain the higher amount of copper on the nests from the fish showing high behaviour scores. Further work is now needed to determine the consequences of the copper binding potential of spiggin in stickleback nests for the health and survival of

  6. Correlation between intracellular accumulation of peptidoglycan precursors and streptomycin formation

    International Nuclear Information System (INIS)

    Nimi, Osamu; Kawashima, Hiroki; Sugiyama, Masanori; Nomi, Ryosaku

    1984-01-01

    When the mycelium of Streptomyces HUT 6037 was suspended in 0.5% NaCl solution containing 14 C-glucosamine, peptidoglycan precursors accumulated in the cells. While UDP-N-acetylglucosamine accumulated in the largest amount among the precursors, extracellularly added and intracellularly accumulated UDP-N-acetylglucosamine were not used to synthesize streptomycin and were probably used for peptidoglycan formation. On the other hand, correlation was recognized between accumulation of glucosamine-6-phosphate (GlcN-6P) and streptomycin formation. Addition of an inhibitor of peptidoglycan synthesis such as enduracidin, vancomycin or cycloserine to a mycelium-suspended culture changed the ratio of accumulated peptidoglycan precursors. When streptomycin formation was stimulated by addition of enduracidin or vancomycin, intracellular GlcN-6P remarkably increased and then decreased rapidly. On the contrary, when cycloserine was added to the culture, no increase of GlcN-6P was observed and streptomycin formation was not stimulated. These results suggest that an increase in the intracellular concentration of GlcN-6P is required for activation or induction of the system for utilizing GlcN-6P for streptomycin formation. (author)

  7. Copper accumulation in COMMD1-knockdown mouse hepatoma cells

    International Nuclear Information System (INIS)

    Miyayama, T.; Ogra, Y.; Hiraoka, D.; Kawaji, F.; Nakamura, E.; Suzuki, N.; Suzuki, K.T.

    2009-01-01

    Complete text of publication follows. It is suggested that mammalian cells strictly regulate copper (Cu) homeostasis. However, the Cu regulation is not fully understood. Cu metabolism domain containing 1 (COMMD1) is a protein which is associated with copper homeostasis in cells. To clarify the function of COMMD1 in Cu excretion, mouse hepatoma cells, Hepa 1-6, targeted on the COMMD1 gene were analyzed by multi-disciplinal techniques consisting of elemental imaging and speciation in addition to molecular and cellular biological techniques. COMMD1 knockdown inhibited the Cu excretion resulting in the Cu accumulation, and Cu accumulating in the cells predominantly existed in the form bound to metallothionein (MT). It is known that Atp7b, an ATP-dependent Cu transporter in the liver, localizes on trans Golgi membrane under basal Cu condition and translocates to cytoplasmic vesicles to excrete Cu when Cu concentration exceeds a certain threshold, and the vesicles disperse in the periphery of the cell. COMMD1 knockdown abolished the relocation of Atp7b from the periphery to the trans Golgi membrane when Cu concentration was returned to normal physiological level on treatment with a Cu (I) chelator. These results suggest that COMMD1 facilitates recruitment of Atp7b from cytoplasmic vesicles to trans Golgi membrane, i.e., COMMD1 is required to shuttle Atp7b when the intracellular Cu level returns to normal physiological level.

  8. Dietary management of labrador retrievers with subclinical hepatic copper accumulation.

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    Fieten, H; Biourge, V C; Watson, A L; Leegwater, P A J; van den Ingh, T S G A M; Rothuizen, J

    2015-01-01

    Genetic and environmental factors, including dietary copper intake, contribute to the pathogenesis of copper-associated hepatitis in Labrador retrievers. Clinical disease is preceded by a subclinical phase in which copper accumulates in the liver. To investigate the effect of a low-copper, high-zinc diet on hepatic copper concentration in Labrador retrievers with increased hepatic copper concentrations. Twenty-eight clinically healthy, client-owned Labrador retrievers with a mean hepatic copper concentration of 919 ± 477 mg/kg dry weight liver (dwl) that were related to dogs previously diagnosed with clinical copper-associated hepatitis. Clinical trial in which dogs were fed a diet containing 1.3 ± 0.3 mg copper/Mcal and 64.3 ± 5.9 mg zinc/Mcal. Hepatic copper concentrations were determined in liver biopsy samples approximately every 6 months. Logistic regression was performed to investigate effects of sex, age, initial hepatic copper concentration and pedigree on the ability to normalize hepatic copper concentrations. In responders (15/28 dogs), hepatic copper concentrations decreased from a mean of 710 ± 216 mg/kg dwl copper to 343 ± 70 mg/kg dwl hepatic copper after a median of 7.1 months (range, 5.5-21.4 months). Dogs from a severely affected pedigree were at increased risk for inability to have their hepatic copper concentrations normalized with dietary treatment. Feeding a low-copper, high-zinc diet resulted in a decrease in hepatic copper concentrations in a subset of clinically normal Labrador retrievers with previous hepatic copper accumulation. A positive response to diet may be influenced by genetic background. Determination of clinical benefit requires further study. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  9. Energetics of copper trafficking between the Atx1 metallochaperone and the intracellular copper transporter, Ccc2.

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    Huffman, D L; O'Halloran, T V

    2000-06-23

    The Atx1 metallochaperone protein is a cytoplasmic Cu(I) receptor that functions in intracellular copper trafficking pathways in plants, microbes, and humans. A key physiological partner of the Saccharomyces cerevisiae Atx1 is Ccc2, a cation transporting P-type ATPase located in secretory vesicles. Here, we show that Atx1 donates its metal ion cargo to the first N-terminal Atx1-like domain of Ccc2 in a direct and reversible manner. The thermodynamic gradient for metal transfer is shallow (K(exchange) = 1.4 +/- 0.2), establishing that vectorial delivery of copper by Atx1 is not based on a higher copper affinity of the target domain. Instead, Atx1 allows rapid metal transfer to its partner. This equilibrium is unaffected by a 50-fold excess of the Cu(I) competitor, glutathione, indicating that Atx1 also protects Cu(I) from nonspecific reactions. Mechanistically, we propose that a low activation barrier for transfer between partners results from complementary electrostatic forces that ultimately orient the metal-binding loops of Atx1 and Ccc2 for formation of copper-bridged intermediates. These thermodynamic and kinetic considerations suggest that copper trafficking proteins overcome the extraordinary copper chelation capacity of the eukaryotic cytoplasm by catalyzing the rate of copper transfer between physiological partners. In this sense, metallochaperones work like enzymes, carefully tailoring energetic barriers along specific reaction pathways but not others.

  10. Transfer and accumulation of lead, zinc, cadmium and copper in ...

    African Journals Online (AJOL)

    Transfer and accumulation of lead, zinc, cadmium and copper in plants growing in abandoned mining-district area. HK Chakroun, F Souissi, JL Bouchardon, R Souissi, J Moutte, O Faure, E Remon, S Abdeljaoued ...

  11. Intracellular accumulation of trehalose and glycogen in an extreme oligotroph, Rhodococcus erythropolis N9T-4.

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    Yano, Takanori; Funamizu, Yuhei; Yoshida, Nobuyuki

    2016-01-01

    An extreme oligotroph, Rhodococcus erythropolis N9T-4, showed intracellular accumulation of trehalose and glycogen under oligotrophic conditions. No trehalose accumulation was observed in cells grown on the rich medium. Deletion of the polyphosphate kinase genes enhanced the trehalose accumulation and decreases the intracellular glycogen contents, suggesting an oligotrophic relationship between among the metabolic pathways of trehalose, glycogen, and inorganic polyphosphate biosyntheses.

  12. Dietary Management of Hepatic Copper Accumulation in Labrador Retrievers

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    Hoffmann, G.; jones, P.G.; Biourge, V.; van den Ingh, T.S.G.A.M.; Mesu, bode; Bode, P.; Rothuizen, J.

    2009-01-01

    J Vet Intern Med. 2009 Sep-Oct;23(5):957-63. Epub 2009 Jul 14. Dietary management of hepatic copper accumulation in Labrador Retrievers. Hoffmann G, Jones PG, Biourge V, van den Ingh TS, Mesu SJ, Bode P, Rothuizen J. Department of Clinical Sciences of Companion Animals, Faculty of Veterinary

  13. Intracellular amyloid formation in muscle cells of Aβ-transgenic Caenorhabditis elegans: determinants and physiological role in copper detoxification

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    Bush Ashley I

    2009-01-01

    Full Text Available Abstract Background The amyloid β-peptide is a ubiquitous peptide, which is prone to aggregate forming soluble toxic oligomers and insoluble less-toxic aggregates. The intrinsic and external/environmental factors that determine Aβ aggregation in vivo are poorly understood, as well as the cellular meaning of this process itself. Genetic data as well as cell biological and biochemical evidence strongly support the hypothesis that Aβ is a major player in the onset and development of Alzheimer's disease. In addition, it is also known that Aβ is involved in Inclusion Body Myositis, a common myopathy of the elderly in which the peptide accumulates intracellularly. Results In the present work, we found that intracellular Aβ aggregation in muscle cells of Caenorhabditis elegans overexpressing Aβ peptide is affected by two single amino acid substitutions, E22G (Arctic and V18A (NIC. Both variations show decrease intracellular amyloidogenesis compared to wild type Aβ. We show that intracellular amyloid aggregation of wild type Aβ is accelerated by Cu2+ and diminished by copper chelators. Moreover, we demonstrate through toxicity and behavioral assays that Aβ-transgenic worms display a higher tolerance to Cu2+ toxic effects and that this resistance may be linked to the formation of amyloid aggregates. Conclusion Our data show that intracellular Aβ amyloid aggregates may trap excess of free Cu2+ buffering its cytotoxic effects and that accelerated intracellular Aβ aggregation may be part of a cell protective mechanism.

  14. Copper homeostasis at the host vibrio interface: lessons from intracellular vibrio transcriptomics.

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    Vanhove, Audrey S; Rubio, Tristan P; Nguyen, An N; Lemire, Astrid; Roche, David; Nicod, Julie; Vergnes, Agnès; Poirier, Aurore C; Disconzi, Elena; Bachère, Evelyne; Le Roux, Frédérique; Jacq, Annick; Charrière, Guillaume M; Destoumieux-Garzón, Delphine

    2016-03-01

    Recent studies revealed that several vibrio species have evolved the capacity to survive inside host cells. However, it is still often ignored if intracellular stages are required for pathogenicity. Virulence of Vibrio tasmaniensis LGP32, a strain pathogenic for Crassostrea gigas oysters, depends on entry into hemocytes, the oyster immune cells. We investigated here the mechanisms of LGP32 intracellular survival and their consequences on the host-pathogen interaction. Entry and survival inside hemocytes were required for LGP32-driven cytolysis of hemocytes, both in vivo and in vitro. LGP32 intracellular stages showed a profound boost in metabolic activity and a major transcription of antioxidant and copper detoxification genes, as revealed by RNA sequencing. LGP32 isogenic mutants showed that resistance to oxidative stress and copper efflux are two main functions required for vibrio intracellular stages and cytotoxicity to hemocytes. Copper efflux was also essential for host colonization and virulence in vivo. Altogether, our results identify copper resistance as a major mechanism to resist killing by phagocytes, induce cytolysis of immune cells and colonize oysters. Selection of such resistance traits could arise from vibrio interactions with copper-rich environmental niches including marine invertebrates, which favour the emergence of pathogenic vibrios resistant to intraphagosomal killing across animal species. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Heavy metals toxicity after acute exposure of cultured renal cells. Intracellular accumulation and repartition

    International Nuclear Information System (INIS)

    Khodja, Hicham; Carriere, Marie; Avoscan, Laure; Gouget, Barbara

    2005-01-01

    Lead (Pb), cadmium (Cd) and uranium (U) present no known biological function but are toxic in various concentration ranges. Pb and Cd lead generally to nephrotoxicity consisting in proximal renal tubular dysfunction and accumulation while U has been reported to induce chemical kidney toxicity, functional and histological damages being as well mainly observed in proximal tubule cells. This work address the question of Cd, Pb, and U cytotoxicity, intracellular accumulation and repartition after acute intoxication of renal proximal tubule epithelial cells. After cells exposure to different concentrations of metals for various times, morphological changes were observed and intracellular concentrations and distributions of toxic metals were specified by PIXE coupled to RBS. Cell viability, measured by biochemical tests, was used as toxicity indicator. A direct correlation between cytotoxicity and intracellular accumulation in renal epithelial cells have been established. Finally, intracellular Pb and U localizations were detected while Cd was found to be uniformly distributed in renal cells. (author)

  16. Intracellular Accumulation of Gold Nanoparticles Leads to Inhibition of Macropinocytosis to Reduce the Endoplasmic Reticulum Stress

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    Gunduz, Nuray; Ceylan, Hakan; Guler, Mustafa O.; Tekinay, Ayse B.

    2017-02-01

    Understanding the toxicity of nanomaterials remains largely limited to acute cellular response, i.e., short-term in vitro cell-death based assays, and analyses of tissue- and organ-level accumulation and clearance patterns in animal models, which have produced very little information about how these materials (from the toxicity point of view) interact with the complex intracellular machinery. In particular, understanding the mechanism of toxicity caused by the gradual accumulation of nanomaterials due to prolonged exposure times is essential yet still continue to be a largely unexplored territory. Herein, we show intracellular accumulation and the associated toxicity of gold nanoparticles (AuNPs) for over two-months in the cultured vascular endothelial cells. We observed that steady exposure of AuNPs at low (non-lethal) dose leads to rapid intracellular accumulation without causing any detectable cell death while resulting in elevated endoplasmic reticulum (ER) stress. Above a certain intracellular AuNP threshold, inhibition of macropinocytosis mechanism ceases further nanoparticle uptake. Interestingly, the intracellular depletion of nanoparticles is irreversible. Once reaching the maximum achievable intracellular dose, a steady depletion is observed, while no cell death is observed at any stage of this overall process. This depletion is important for reducing the ER stress. To our knowledge, this is the first report suggesting active regulation of nanoparticle uptake by cells and the impact of long-term exposure to nanoparticles in vitro.

  17. Intracellular boron accumulation in CHO-K1 cells using amino acid transport control

    International Nuclear Information System (INIS)

    Sato, Eisuke; Yamamoto, Tetsuya; Shikano, Naoto; Ogura, Masato; Nakai, Kei; Yoshida, Fumiyo; Uemae, Yoji; Takada, Tomoya; Isobe, Tomonori; Matsumura, Akira

    2014-01-01

    BPA used in BNCT has a similar structure to some essential amino acids and is transported into tumor cells by amino acid transport systems. Previous study groups have tried various techniques of loading BPA to increase intracellular boron concentration. CHO-K1 cells demonstrate system L (LAT1) activity and are suitable for specifying the transport system of a neutral amino acid. In this study, we examined the intracellular accumulation of boron in CHO-K1 cells by amino acid transport control, which involves co-loading with L-type amino acid esters. Intracellular boron accumulation in CHO-K1 cells showed the greatest increased upon co-loading 1.0 mM BPA, with 1.0 mM L-Tyr-O-Et and incubating for 60 min. This increase is caused by activation of a system L amino acid exchanger between BPA and L-Tyr. The amino acid esters are metabolized to amino acids by intracellular hydrolytic enzymes that increase the concentrations of intracellular amino acids and stimulate exchange transportation. We expect that this amino acid transport control will be useful for enhancing intracellular boron accumulation. - Highlights: • We examined optimal L-p-boronophenylalanine (BPA) loading in CHO-K1 cells. • Optimal BPA loading parameters were 1.0 mM and incubation for 60 min. • Intracellular boron accumulation increased upon co-loading BPA with L-Tyr-O-Et. • Optimal L-Tyr-O-Et loading parameters were 1.0 mM and incubation for 60 min. • Co-loading BPA with L-Tyr-O-Et can increase intracellular boron accumulation

  18. Pulsed magneto-motive ultrasound imaging to detect intracellular accumulation of magnetic nanoparticles

    International Nuclear Information System (INIS)

    Mehrmohammadi, Mohammad; Qu Min; Sokolov, Konstantin V; Emelianov, Stanislav Y; Ma, Li L; Johnston, Keith P; Romanovicz, Dwight K

    2011-01-01

    As applications of nanoparticles in medical imaging and biomedicine rapidly expand, the interactions of nanoparticles with living cells have become an area of active interest. For example, intracellular accumulation of nanoparticles-an important part of cell-nanoparticle interaction-has been well studied using plasmonic nanoparticles and optical or optics-based techniques due to the change in optical properties of the nanoparticle aggregates. However, magnetic nanoparticles, despite their wide range of clinical applications, do not exhibit plasmonic-resonant properties and therefore their intracellular aggregation cannot be detected by optics-based imaging techniques. In this study, we investigated the feasibility of a novel imaging technique-pulsed magneto-motive ultrasound (pMMUS)-to identify intracellular accumulation of endocytosed magnetic nanoparticles. In pMMUS imaging a focused, high intensity, pulsed magnetic field is used to excite the cells labeled with magnetic nanoparticles, and ultrasound imaging is then used to monitor the mechanical response of the tissue. We demonstrated previously that clusters of magnetic nanoparticles amplify the pMMUS signal in comparison to the signal from individual nanoparticles. Here we further demonstrate that pMMUS imaging can identify interaction between magnetic nanoparticles and living cells, i.e. intracellular accumulation of nanoparticles within the cells. The results of our study suggest that pMMUS imaging can not only detect the presence of magnetic nanoparticles but also provides information about their intracellular accumulation non-invasively and in real-time.

  19. Als1 and Als3 regulate the intracellular uptake of copper ions when Candida albicans biofilms are exposed to metallic copper surfaces.

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    Zheng, Sha; Chang, Wenqiang; Li, Chen; Lou, Hongxiang

    2016-05-01

    Copper surfaces possess efficient antimicrobial effect. Here, we reported that copper surfaces could inactivate Candida albicans biofilms within 40 min. The intracellular reactive oxygen species in C. albicans biofilms were immediately stimulated during the contact of copper surfaces, which might be an important factor for killing the mature biofilms. Copper release assay demonstrated that the copper ions automatically released from the surface of 1 mm thick copper coupons with over 99.9% purity are not the key determinant for the copper-mediated killing action. The susceptibility test to copper surfaces by using C. albicans mutant strains, which were involved in efflux pumps, adhesins, biofilms formation or osmotic stress response showed that als1/als1 and als3/als3 displayed higher resistance to the copper surface contact than other mutants did. The intracellular concentration of copper ions was lower in als1/als1 and als3/als3 than that in wild-type strain. Transcriptional analysis revealed that the expression of copper transporter-related gene, CRP1, was significantly increased in als1/als1, als3/als3, suggesting a potential role of ALS1 and ALS3 in absorbing ions by regulating the expression of CRP1 This study provides a potential application in treating pathogenic fungi by using copper surfaces and uncovers the roles of ALS1 and ALS3 in absorbing copper ions for C. albicans. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Accumulation of Copper and Zinc and their Effects on Growth and ...

    African Journals Online (AJOL)

    Accumulation and the effects of copper and zinc on the macroalga Padina gymnospora were assessed in the laboratory after artificial exposure to copper and zinc (separately or in combination). Exposure concentrations of copper used were 0, 25, 50, 100, 500 and 1,000 μg l-1. Concentrations of zinc exposure were 0, 50, ...

  1. Liver-Specific Commd1 Knockout Mice Are Susceptible to Hepatic Copper Accumulation

    NARCIS (Netherlands)

    Vonk, Willianne I. M.; Bartuzi, Paulina; de Bie, Prim; Kloosterhuis, Niels; Wichers, Catharina G. K.; Berger, Ruud; Haywood, Susan; Klomp, Leo W. J.; Wijmenga, Cisca; van de Sluis, Bart

    2011-01-01

    Canine copper toxicosis is an autosomal recessive disorder characterized by hepatic copper accumulation resulting in liver fibrosis and eventually cirrhosis. We have identified COMMD1 as the gene underlying copper toxicosis in Bedlington terriers. Although recent studies suggest that COMMD1

  2. Betacyanin accumulation and guaiacol peroxidase activity in Beta vulgaris L. leaves following copper stress

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    Janet M. León Morales

    2012-07-01

    Full Text Available The effect of copper stress on betacyanin accumulation and guaiacol peroxidase (GPOD activity in leaves of different age was evaluated in red beet (Beta vulgaris L. var. Crosby Egyptian plants. In hydroponic culture, plants were treated with 0.3 μM (control, 50 μM, 100 μM, and 250 μM of CuSO4 for 6 days. Copper was taken up and accumulated in old roots but was not translocated to leaves. However in young leaves, the increase of lipid peroxidation and reduction of growth were evident from day 3 of copper exposure; whereas in old leaves, the lipid peroxidation and growth were the same from either copper-treated or control plants. In response to copper exposure, the betacyanin accumulation was evident in young leaves by day 3, and continued to increase until day 6. Betacyanin only were accumulated in old leaves until day 6, but the contents were from 4 to 5 times lower than those observed in young leaves at the same copper concentrations. GPOD activity increased 3.3- and 1.4-fold in young and old leaves from day 3 of copper treatment respectively, but only in the young leaves was sustained at the same level until day 6. Old roots shown betacyanin in the control plants, but the betacyanin level and growth were reduced with the copper exposure. In contrast, young roots emerged by copper effect also accumulated copper and showed the highest betacyanin content of all plant parts assayed. These results indicate that betacyanin accumulation and GPOD activity are defense responses to copper stress in actively growing organs.

  3. Molecular mechanism of intracellular lipid accumulation: Suppressive effect of PycnogenolR in liver cells

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    Shoichiro Ikuyama

    2013-09-01

    Full Text Available ABSTRACTCells are physiologically ready to accumulate lipids such as triacylglycerides in the cytoplasm.Five classes of perilipin (PLIN family proteins are known to be involved in the process of intracellular lipid accumulation. PLIN2 is expressed ubiquitously including adipocytes, hepatocytes and macrophages. Over-expression of PLIN2 is demonstrated in the lesions of fatty liver diseases and atherosclerosis. Suppression of PLIN2 expression prevents from developing these pathological conditions in animal models, suggesting that PLIN2 could be a therapeutic target molecule for excessive intracellular lipid accumulation which leads to various metabolic derangements. The PLIN2 gene promoter has two important cis-acting elements in close proximity:AP-1 element which mediates inflammatory signals and PPRE which mediates free fatty acid effect. In NMuLi mouse liver cells, FFA such as oleic acid requires both functional AP-1 and PPRE simultaneously to stimulate the promoter activity, indicating the presence of intimate interaction of inflammatory and metabolic signals on this gene. PycnogenolR, French maritime pine bark extracts, suppressed the oleic acid-induced PLIN2 expression and lipid accumulation in NMuLi cells. We found that PycnogenolR did not suppress the PLIN2 promoter activity or AP-1 binding to DNA. Instead, PycnogenolRfacilitates the PLIN2 mRNA degradation, leading to suppression of lipid accumulation. This effect seems to be independent of antioxidant effect of PycnogenolR.We raise the idea that PLIN2 is a putative target molecule for prevention of pathological condition induced by excessive lipid accumulation, and this class of natural compounds could be putative therapeutic modalities.Key words: PycnogenolR, lipid droplet, perilipin, fatty liver disease

  4. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

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    Acar, Handan [Institute; Department; Samaeekia, Ravand [Institute; Department; Schnorenberg, Mathew R. [Institute; Department; Medical; Sasmal, Dibyendu K. [Institute; Huang, Jun [Institute; Tirrell, Matthew V. [Institute; Institute; LaBelle, James L. [Department

    2017-08-24

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  5. Intracellular vorinostat accumulation and its relationship to histone deacetylase activity in soft tissue sarcoma patients.

    Science.gov (United States)

    Burhenne, Jürgen; Liu, Lu; Heilig, Christoph E; Meid, Andreas D; Leisen, Margarete; Schmitt, Thomas; Kasper, Bernd; Haefeli, Walter E; Mikus, Gerd; Egerer, Gerlinde

    2017-08-01

    In the regulation of chromatin-structure and histone function, histone deacetylases (HDACs) are key enzymes and thus modulators of epigenetic regulation and gene expression. Accesses of the HDAC inhibitor vorinostat to intracellular compartments are essential to exert epigenetic effects. In ten sarcoma patients receiving oral Zolinza (400 mg qd) vorinostat concentrations in plasma and peripheral blood mononuclear cells (PBMCs) were quantified using validated LC/MS/MS assays to determine intracellular and extracellular pharmacokinetic data. Cellular HDAC activity was evaluated using a fluorogenic assay. Concentration-response relationships were established between intracellular and extracellular vorinostat concentrations and HDAC inhibition in PBMCs. Pharmacokinetics of vorinostat and its two main inactive metabolites were determined over 8 h in plasma and PBMCs. Steady state AUCs (±SD) and T 1/2 (±SD) were calculated to 4.61 ± 0.87 h µM and 1.73 ± 0.69 h (plasma) and 15.2 ± 9.03 h µM and 5.30 ± 4.27 h (PBMCs). Intracellular accumulation of vorinostat was determined together with prolonged vorinostat elimination in PBMCs. Cellular HDAC inhibition increased parallel with vorinostat concentrations in plasma and PBMCs. For effective inhibition of cellular HDACs (IC 50 ) vorinostat concentrations of 0.05 µM in plasma and 0.17 µM in PBMCs were necessary. HDAC inhibition closely followed intracellular vorinostat concentrations and was short-lasting, which may contribute to the limited efficacy seen with vorinostat in solid tumors so far.

  6. EFFECT OF CONCENTRATION AND EXPOSURE TIME ON COPPER ACCUMULATION IN EICHHORNIA CRASSIPES (MART. SOLMS. (PONTEDERIACEAE

    Directory of Open Access Journals (Sweden)

    S. Lunardi

    2017-12-01

    Full Text Available Different factors can influence the absorption and storage of substances in plant biomass. In this study, we evaluated the effect of copper concentration in growth medium and plant exposure time on copper accumulation in Eichhornia crassipes (Mart. Solms. (Pontederiaceae roots and leaves under controlled conditions. Plants were subjected to four treatments of copper concentrations of 1, 3 and 5 μg.mL-1, with a control treatment of 0 μg.mL-1, and evaluated at seven-day intervals over 21 days. Copper concentration in biomass was analysed by atomic absorption spectroscopy with flame atomisation. The results showed that copper concentration in the growth medium and time of exposure had a significant effect on the amount of copper accumulated by E. crassipes roots and leaves, with roots more efficient compared to leaves. It is likely that E. crassipes has mechanisms for the translocation of metal from the root system to the leaves. Symptoms of copper toxicity were observed in the vegetative parts of the plants at the end of the experiments. This study demonstrates that E. crassipes presents great potential in the absorption and accumulation of copper under laboratory conditions, indicating its effectiveness for applications in phytoremediation processes.

  7. Laser microscope-spectrum analyzer for studying intracellular accumulation of near infrared emitting photosensitizers in vitro

    Directory of Open Access Journals (Sweden)

    Yu. S. Maklygina

    2015-01-01

    Full Text Available Measuring system based on the binocular microscope for analysis of intracellular accumulation of infrared IR photosenstizers allowing to obtain graphic data about state of analyzed objects, location of fluorescence foci and to obtain details of spectral profile of fluorescence emission centers in IR spectral region was developed. According to image of fluorescence signal distribution the location of photosensitizer accumulation in the cell may be detected accurately and the spectrum of fluorescence signal of near IR-range in the targeted point may be obtained. The developed system is quite comprehensive because there is an opportunity to choose technical parameters, operating modes, measuring methods and analysis. The advantage of the developed microscope-spectrum analyzer is an opportunity to focus emission and create high power intensity on the irradiated area by means of laser source with small-angle beam spreading, all this allow to perform ultra-precise operations with cells. Particularly, tunable size of the diaphragm opening in the far field allows to register fluorescence signal on certain cell organoids. By means of developed system the studies of accumulation of the new bacteriochlorine photosensitizers on HeLa cell line were performed. The system allowed to register accumulation of cancer cells with definite sites of selectively accumulated photosensitizer. The sites of fluorescence were the centers of accumulation of bacteriochlorine photosensitizer, this suggests that studied photosensitizer has a tendency for local accumulation in cellular organoids. The authors suggested that the developed system allowed to perform the effective and rapid screening of new photosensitizers, particularly IR bacteriochlorine photosensitizers. 

  8. Copper Deficiency in Sheep with High Liver Iron Accumulation

    Directory of Open Access Journals (Sweden)

    Isadora Karolina Freitas de Sousa

    2012-01-01

    Full Text Available An outbreak of enzootic ataxia among sheep raised in the northeastern region of Brazil is described. Copper (Cu deficiency was diagnosed in a herd of 56 sheep, among which five presented characteristic clinical symptoms of enzootic ataxia. The symptoms began 30 days after birth, with a clinical condition that included locomotion difficulty, limb ataxia, tremors, and continual falls. Liver biopsies were performed and blood was collected to determine hepatic and plasmatic Cu, iron (Fe, and zinc (Zn concentration, respectively. The laboratory results showed that the animals presented low copper concentrations in the plasma and liver, without difference between the clinically healthy animals and those affected by enzootic ataxia. Even after supplementation with adequate Cu levels had been recommended, it was found on a new visit to the farm four months later that one animal still presented a clinical condition and that the hepatic Cu levels of the herd had not risen. Despite the low copper content of the diet, the high hepatic Fe levels found suggest that antagonism due to this element may have been an important factor in triggering copper deficiency in these animals, and thus, additional copper supplementation may be necessary for these animals.

  9. Mobilization of Intracellular Copper by Gossypol and Apogossypolone Leads to Reactive Oxygen Species-Mediated Cell Death: Putative Anticancer Mechanism

    Directory of Open Access Journals (Sweden)

    Haseeb Zubair

    2016-06-01

    Full Text Available There is compelling evidence that serum, tissue and intracellular levels of copper are elevated in all types of cancer. Copper has been suggested as an important co-factor for angiogenesis. It is also a major metal ion present inside the nucleus, bound to DNA bases, particularly guanine. We have earlier proposed that the interaction of phenolic-antioxidants with intracellular copper leads to the generation of reactive oxygen species (ROS that ultimately serve as DNA cleaving agents. To further validate our hypothesis we show here that the antioxidant gossypol and its semi-synthetic derivative apogossypolone induce copper-mediated apoptosis in breast MDA-MB-231, prostate PC3 and pancreatic BxPC-3 cancer cells, through the generation of ROS. MCF10A breast epithelial cells refractory to the cytotoxic property of these compounds become sensitized to treatment against gossypol, as well as apogossypolone, when pre-incubated with copper. Our present results confirm our earlier findings and strengthen our hypothesis that plant-derived antioxidants mobilize intracellular copper instigating ROS-mediated cellular DNA breakage. As cancer cells exist under significant oxidative stress, this increase in ROS-stress to cytotoxic levels could be a successful anticancer approach.

  10. Accumulation of cadmium and copper by the terrestrial snail Arianta arbustorum L. : Kinetics and budgets

    Energy Technology Data Exchange (ETDEWEB)

    Berger, B.; Dallinger, R. (Innsbruck Univ. (Austria). Abt. Zoophysiologie)

    1989-01-01

    Specimens of the terrestrial gastropod Arianta arbustorum were fed on cadmium- or copper-enriched agar plates with the aim of performing an input/output analysis and of studying the distribution of these metals in several organs of the snails. After a feeding period of 20 days about 45% of cadmium were lost. 36% accumulated in the hepatopancreas, where a cadmium concentration of more than 500 {mu}g/g was measured. The efficiency of cadmium assimilation decreased from about 90% at the beginning to about 55% after 20 days. Copper was distributed more evenly than cadmium, but the main site of copper storage seemed to be the foot/mantle tissues, where 49% of the ingested copper were found. The efficiency of copper assimilation always exceeded 95%. The patterns of distribution and assimilation of copper and cadmium are discussed in relation to differences in the cytological and biochemical detoxification mechanisms which exist for these metals in molluscs. (orig.).

  11. Accumulation of copper and zinc by balanus amphitrite in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Anil, A.C.; Wagh, A.B.

    @iBalanus amphitrite@@ (Cirripedia: Thoracica) a dominant fouling organism was analysed to assess the accumulation potentialities of copper and zinc. It was observed that it could accumulate Cu to 864.77 mu g g-1 dry wt. and Zn to 1937.50 mu g g-1...

  12. Soluble Moringa oleifera leaf extract reduces intracellular cadmium accumulation and oxidative stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kerdsomboon, Kittikhun; Tatip, Supinda; Kosasih, Sattawat; Auesukaree, Choowong

    2016-05-01

    Moringa oleifera leaves are a well-known source of antioxidants and traditionally used for medicinal applications. In the present study, the protective action of soluble M. oleifera leaf extract (MOLE) against cadmium toxicity was investigated in the model eukaryote Saccharomyces cerevisiae. The results showed that this extract exhibited a protective effect against oxidative stress induced by cadmium and H2O2 through the reduction of intracellular reactive oxygen species. Interestingly, not only the co-exposure of soluble MOLE with cadmium but also pretreatment of this extract prior to cadmium exposure significantly reduced the cadmium uptake through an inhibition of Fet4p, a low-affinity iron(II) transporter. In addition, the supplementation of soluble MOLE significantly reduced intracellular iron accumulation in a Fet4p-independent manner. Our findings suggest the potential use of soluble extract from M. oleifera leaves as a dietary supplement for protection against cadmium accumulation and oxidative stress. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Accumulation of copper by the aquatic macrophyte Salvinia biloba Raddi (Salviniaceae

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    F. Freitas

    2017-07-01

    Full Text Available Abstract Aquatic macrophytes have properties and mechanisms which are useful for the removal of substances in solution, commonly used in phytoremediation processes in aquatic environments. This study evaluated the performance of copper (Cu accumulation by Salvinia biloba Raddi (Salviniaceae in different metal concentrations (1, 3 and 5 µg mL-1, as well as the control treatment, measured at intervals of 0, 7 and 14 days under laboratory conditions, with control as to pH and luminosity. After the experiment, the S. biloba biomass was washed, kiln dried, crushed and subjected to the process of digestion, and subsequently the accumulated copper content was determined by atomic absorption spectroscopy. The results showed that S. biloba is apt at accumulating copper, varying significantly between different treatments and days of exposure to the contaminant, as well as its interaction (treatment × days. The highest accumulation values were observed in treatment with 5 µg mL-1, which at 14 days, with 11,861 µg g-1 of copper. We observed symptoms of toxicity and mortality in plants, probably indicating the effect of copper on the species when at high levels. Salvinia biloba is an efficient species in the removal of copper in solution, its recommendation as a remediating agent in aquatic ecosystems being possible.

  14. Interactions between accumulated copper, bacterial community structure and histamine levels in crayfish meat during storage.

    Science.gov (United States)

    Soedarini, Bernadeta; van Gestel, Cornelis A M; van Straalen, Nico M; Widianarko, Budi; Röling, Wilfred F M

    2014-08-01

    Pollution in aquaculture areas may negatively impact edible species and threaten seafood quality and safety. The aim of this study was to determine the interaction between copper and bacteria in the aquatic habitat and their impact upon crustaceans. Marbled crayfish was chosen as a model of aquatic crustaceans and the influence of metal contamination on bacterial community structure in water used to culture crayfish and in crayfish themselves was investigated. Histamine, an allergen commonly formed by certain groups of bacteria in crustacean edible tissue during storage, was also determined. Copper exposure increased its concentration in crayfish meat by 17.4%, but the copper concentration remained within acceptable food safety limits. Elevated copper levels affected the bacterial community both in the water used to cultivate crayfish and in the marbled crayfish themselves. Cluster analysis of 16S rRNA-gene based microbial community fingerprints revealed that copper impacted the bacterial community in the water and in the crayfish meat. However, copper exposure reduced the formation of histamine in crayfish meat during storage by 66.3%. Copper from the habitat appears to reduce histamine accumulation in crayfish meat during storage by affecting the bacterial community structure of the cultivation water and most likely also in the intestine of the crayfish. From a food safety point of view, copper treatment during the aqua culturing of crustaceans has a positive impact on the postharvest stage. © 2013 Society of Chemical Industry.

  15. Nutrition influence on copper accumulation by Brassica pekinensis Rupr.

    Science.gov (United States)

    Xiong, Zhi-Ting; Li, Yi-Hong; Xu, Bin

    2002-10-01

    Effect of nutrition status in the growth medium on Cu accumulation and plant growth were tested in Brassica pekinensis grown in hydroponic culture in a cultural facility. Cu concentration in the roots and shoots increased with increasing external Cu in the culture solution. On the other hand, it decreased with increasing Hoagland's solution (HS) strength. Interaction between external Cu and HS strength was also observed to affect Cu concentration in the tissues. A low level of external Cu could lead to a high Cu concentration in the plant at low HS strength, while to obtain a high Cu concentration in the plant at high HS strength, a high level of external Cu was needed. Partial nutrient experiments showed an important role of Fe and P in governing Cu accumulation. The influence of nutrients on Cu accumulation were mainly attributed to the osmolarity of the nutrient solution, antagonism between nutrients and Cu, pH change, and cation transporter induction. Root length and shoot biomass were negatively related to Cu concentration in the plant, suggesting an adverse effect of Cu in the tissue on plant growth. Root biomass showed less response to Cu concentration in the plant. This was presumably due to plant resource allocation between shoot and root, by which more resources were shifted to the Cu-stressed roots. The results might have important implications in understanding the sterility of the growth media of plants on Cu fate and effect in the ecosystem.

  16. Accumulation of cadmium, copper, lead, zinc and iron in the edible ...

    African Journals Online (AJOL)

    TANIMA

    The permissible limits of heavy metals for food safety set by different countries are shown in Table 3. The present study shows that oysters accumulated a considerable amount of metals in their body cells. The concentration of the metals like cadmium, copper, lead, zinc and iron in oyster tissue collected from Shankarpur.

  17. Acute toxicity and bio-accumulation of mercury and copper in ...

    African Journals Online (AJOL)

    The acute toxicity of Mercury and Copper on C. africanus and T. fuscatus and the bio-accumulation potentials of the metals were investigated in laboratory experiments employing standard bio–assay techniques. On the basis of LC50 values, both metals had similar magnitudes of toxicity against C. africanus. However ...

  18. Accumulation of intra-cellular polyphosphate in Chlorella vulgaris cells is related to indole-3-acetic acid produced by Azospirillum brasilense.

    Science.gov (United States)

    Meza, Beatriz; de-Bashan, Luz E; Hernandez, Juan-Pablo; Bashan, Yoav

    2015-06-01

    Accumulation of intra-cellular phosphate, as polyphosphate, was measured when the microalga Chlorella vulgaris was immobilized in alginate with either of two wild-type strains of the microalgae growth-promoting bacterium Azospirillum brasilense or their corresponding IAA-attenuated mutants. Wild type strains of A. brasilense induced higher amounts of intra-cellular phosphate in Chlorella than their respective mutants. Calculations comparing intra-cellular phosphate accumulation by culture or net accumulation by the cell and the amount of IAA that was produced by each of these strains revealed that higher IAA was linked to higher accumulations of intra-cellular phosphate. Application of four levels of exogenous IAA reported for A. brasilense and their IAA-attenuated mutants to cultures of C. vulgaris enhanced accumulation of intra-cellular phosphate; the higher the content of IAA per culture or per single cell, the higher was the amount of accumulated phosphate. When an IAA-attenuated mutant was complemented with exogenous IAA, accumulation of intra-cellular phosphate at the culture level was even higher than phosphate accumulation with the respective wild type strains. When calculating the net accumulation of intra-cellular phosphate in the complementation experiment, net intra-cellular phosphate induced by the IAA-attenuated mutant was completely restored and was similar to the wild strains. We propose that IAA produced by A. brasilense is linked to polyphosphate accumulation in C. vulgaris. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  19. Effects of aqueous stable fullerene nanocrystal (nC60) on copper (trace necessary nutrient metal): Enhanced toxicity and accumulation of copper in Daphnia magna.

    Science.gov (United States)

    Tao, Xianji; He, Yiliang; Fortner, John D; Chen, Yongsheng; Hughes, Joseph B

    2013-08-01

    Our focus herein is to evaluate the potential interaction between nC60 and copper, a trace necessary metal, in light of the impact on toxicity. The non-observable effects concentration (NOEC) of nC60 was confirmed as 100μgL(-1) before. When Daphnia magna was exposed to the mixture of copper solution and nC60 suspension (100μgL(-1)), LC50 of 48h was lower than that when they were exposed to copper solution alone. This result clearly showed the decrease in NOEC of copper at the presence of nC60. Cu(2+)-ATPase activity was enhanced at the presence of nC60, indicating that copper transport involved with the uptake, distribution and depuration in body was increased. We further conducted experiments on accumulation of copper in D. magna. The observed equilibrium copper concentration in D. magna in the mixture of 100μgL(-1) nC60 and 1μgL(-1) copper solution reached 131μg (kg wet weight)(-1), which was more than twice that in copper solution only: 60μg (kg wet weight)(-1). This result demonstrated that the accumulation of copper in D. magna was significantly enhanced at the presence of even low nC60 concentration. Experiments also showed that copper was quickly adsorbed onto nC60. The absorption of copper onto D. magna was statistically correlated to the absorption of nC60 onto D. magna; this might be caused by nC60 facilitating the transfer of copper into D. magna. The absorption and desorption of copper to nC60 (pH=5.0) reached equilibrium quickly, which may be involved with the co-bioaccumulation and decrease in NOEC of Cu(2+) and nC60. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. COPPER ACCUMULATION IN SOILS AND VEGETATION OF POLLUTED AREA COPŞA MICĂ

    Directory of Open Access Journals (Sweden)

    Nicoleta Vrînceanu

    2010-01-01

    Full Text Available The study carried out in order to estimate the distribution and accumulation of copper in soils and vegetation fromCopşa Mică area used a radial network centered in the source of pollution – S.C. SOMETRA S.A. Copşa Mică. Soil andplant samples taken from the radial nodes of the network were analyzed to determine the content of copper. Values ofcopper content in plant ranged between 4.2 mg/kg and 97 mg/kg. Based on these results has been obtained a regressionequation that estimates the copper content in plants as function of the total copper content in soil. The spontaneousvegetation developed in the investigated area includes plants belonging to the following species: Amaranthusretroflexus, Artemisia vulgaris, Asclepias syriaca, Calamagrostis epigeios, Calamagrostis pseudophragmites, Cynodondactylon, Daucus carota, Equisetum arvense, Phragmites australis, Picris hieracioides, Setaria glauca, Sinapisarvensis, Verbascum phlomoides and Xanthium strumarium. The copper pollution doesn’t represent a major problem inCopşa Mică area.

  1. Exogenous salicylate application affects the lead and copper accumulation characteristics of Lemna gibba L.

    Energy Technology Data Exchange (ETDEWEB)

    Duman, Fatih; Aksoy, Ahmet; Ozturk, Fatma; Ceylan, Ahmet [Erciyes Univ., Kayseri (Turkey). Dept. of Biology

    2010-11-15

    Previous studies have shown that salicylates can change the ion permeability of root cells. Therefore the possible effects of exogenous salicylate application on lead (Pb) and copper (Cu) accumulation and its protective role against DNA damage due to metal exposure in Lemna gibba were studied. L. gibba was exposed to 5, 10, and 25 {mu}M Pb and Cu for six days in the presence and absence of sodium salicylate (SA) (0.1, 0.5, and 1 mM). At all concentrations tested, SA application decreased Pb accumulation. On the other hand, application of 0.5 mM SA increased Cu accumulation. SA did not reduce DNA damage resulting from Pb and Cu toxicity. In summary, SA may be useful for reducing Pb accumulation, and application of SA at 0.5 mM may be useful for the phytoextraction of Cu. (orig.)

  2. Azelnidipine prevents cardiac dysfunction in streptozotocin-diabetic rats by reducing intracellular calcium accumulation, oxidative stress and apoptosis

    Directory of Open Access Journals (Sweden)

    Kain Vasundhara

    2011-11-01

    Full Text Available Abstract Background Numerous evidences suggest that diabetic heart is characterized by compromised ventricular contraction and prolonged relaxation attributable to multiple causative factors including calcium accumulation, oxidative stress and apoptosis. Therapeutic interventions to prevent calcium accumulation and oxidative stress could be therefore helpful in improving the cardiac function under diabetic condition. Methods This study was designed to examine the effect of long-acting calcium channel blocker (CCB, Azelnidipine (AZL on contractile dysfunction, intracellular calcium (Ca2+ cycling proteins, stress-activated signaling molecules and apoptosis on cardiomyocytes in diabetes. Adult male Wistar rats were made diabetic by a single intraperitoneal (IP injection of streptozotocin (STZ. Contractile functions were traced from live diabetic rats to isolated individual cardiomyocytes including peak shortening (PS, time-to-PS (TPS, time-to-relengthening (TR90, maximal velocity of shortening/relengthening (± dL/dt and intracellular Ca2+ fluorescence. Results Diabetic heart showed significantly depressed PS, ± dL/dt, prolonged TPS, TR90 and intracellular Ca2+ clearing and showed an elevated resting intracellular Ca2+. AZL itself exhibited little effect on myocyte mechanics but it significantly alleviated STZ-induced myocyte contractile dysfunction. Diabetes increased the levels of superoxide, enhanced expression of the cardiac damage markers like troponin I, p67phox NADPH oxidase subunit, restored the levels of the mitochondrial superoxide dismutase (Mn-SOD, calcium regulatory proteins RyR2 and SERCA2a, and suppressed the levels of the anti-apoptotic Bcl-2 protein. All of these STZ-induced alterations were reconciled by AZL treatment. Conclusion Collectively, the data suggest beneficial effect of AZL in diabetic cardiomyopathy via altering intracellular Ca2+ handling proteins and preventing apoptosis by its antioxidant property.

  3. Accumulation, subcellular distribution and toxicity of copper in earthworm (Eisenia fetida) in the presence of ciprofloxacin.

    Science.gov (United States)

    Huang, Rixiang; Wen, Bei; Pei, Zhiguo; Shan, Xiao-Quan; Zhang, Shuzhen; Williams, Paul N

    2009-05-15

    Land application of wastes from concentrated animal feeding operations results in accumulation of copper (Cu) and antimicrobials in terrestrial systems. Interaction between Cu and antimicrobials may change Cu speciation in soil solution, and affect Cu bioavailability and toxicity. In this study, earthworms were exposed to quartz sand percolated with different concentrations of Cu and ciprofloxacin (CIP). Copper uptake by earthworms, its subcellular partition, and toxicity were studied. An increase in the applied CIP decreased the free Cu ion concentration in external solution and mortalities of earthworm, while Cu contents in earthworms increased. Copper and CIP in earthworms were fractionated into five fractions: a granular fraction (D), a fraction consisting of tissue fragments, cell membranes, and intact cells (E), a microsomal fraction (F), a denatured proteins fraction (G), and a heat-stable proteins fraction (H). Most of the CIP in earthworms was in fraction H. Copper was redistributed from the metal-sensitive fraction E to fractions D, F, G, and H with increasing CIP concentration. These results challenge the free ion activity model and suggested that Cu may be partly taken up as Cu-CIP complexes in earthworms, changing the bioavailability, subcellular distribution, and toxicity of Cu to earthworms.

  4. Effects of pH on copper accumulation and toxicity in the common carp, Cyprinus carpio.

    Science.gov (United States)

    Roopadevi, H; Somashekar, R K; Balagangadhar, B R

    2011-07-01

    Static, short-term acute toxicity tests were performed over a period of 96h, using different concentrations of copper on common carp (Cyprinus carpio) fingerlings (3.2 +/- 1.1 cm and 0.42 g +/- 0.2 g) at pH 6.5, pH 7.5 and pH 8.5. The effect of copper on carp was significantly high (determined as LC50) at pH 6.5 followed by pH 7.5 and pH 8.5. The lethal toxic effect of copper on common carp was directly proportional to pH. Exposure to sub-lethal doses of 0.25, 0.3, 0.35, 0.45 ppm for 15 days indicated that metal concentration and exposure time are determining factors in the copper accumulation processes. Nonetheless the BAF (Bioaccumulation factor) was found to be inversely proportional to cumulative dosage and duration.

  5. Involvement of indole-3-acetic acid produced by Azospirillum brasilense in accumulating intracellular ammonium in Chlorella vulgaris.

    Science.gov (United States)

    Meza, Beatriz; de-Bashan, Luz E; Bashan, Yoav

    2015-01-01

    Accumulation of intracellular ammonium and activities of the enzymes glutamine synthetase (GS) and glutamate dehydrogenase (GDH) were measured when the microalgae Chlorella vulgaris was immobilized in alginate with either of two wild type strains of Azospirillum brasilense or their corresponding indole-3-acetic acid (IAA)-attenuated mutants. After 48 h of immobilization, both wild types induced higher levels of intracellular ammonium in the microalgae than their respective mutants; the more IAA produced, the higher the intracellular ammonium accumulated. Accumulation of intracellular ammonium in the cells of C. vulgaris followed application of four levels of exogenous IAA reported for A. brasilense and its IAA-attenuated mutants, which had a similar pattern for the first 24 h. This effect was transient and disappeared after 48 h of incubation. Immobilization of C. vulgaris with any bacteria strain induced higher GS activity. The bacterial strains also had GS activity, comparable to the activity detected in C. vulgaris, but weaker than when immobilized with the bacteria. When net activity was calculated, the wild type always induced higher GS activity than IAA-attenuated mutants. GDH activity in most microalgae/bacteria interactions resembled GS activity. When complementing IAA-attenuated mutants with exogenous IAA, GS activity in co-immobilized cultures matched those of the wild type A. brasilense immobilized with the microalga. Similarity occurred when the net GS activity was measured, and was higher with greater quantities of exogenous IAA. It is proposed that IAA produced by A. brasilense is involved in ammonium uptake and later assimilation by C. vulgaris. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  6. Spatial Pattern of Copper Phosphate Precipitation Involves in Copper Accumulation and Resistance of UnsaturatedPseudomonas putidaCZ1 Biofilm.

    Science.gov (United States)

    Chen, Guangcun; Lin, Huirong; Chen, Xincai

    2016-12-28

    Bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. The spatial distribution and speciation of copper in unsaturated Pseudomonas putida CZ1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive X-ray analysis, and micro-X-ray fluorescence microscopy coupled with micro-X-ray absorption near edge structure (micro-XANES) analysis. It was found that copper was mainly precipitated in a 75 μm thick layer as copper phosphate in the middle of the biofilm, while there were two living cell layers in the air-biofilm and biofilm-medium interfaces, respectively, distinguished from the copper precipitation layer by two interfaces. The X-ray absorption fine structure analysis of biofilm revealed that species resembling Cu₃(PO₄)₂ predominated in biofilm, followed by Cu-Citrate- and Cu-Glutathione-like species. Further analysis by micro-XANES revealed that 94.4% of copper were Cu₃(PO₄)₂-like species in the layer next to the air interface, whereas the copper species of the layer next to the medium interface were composed by 75.4% Cu₃(PO₄)₂, 10.9% Cu-Citrate-like species, and 11.2% Cu-Glutathione-like species. Thereby, it was suggested that copper was initially acquired by cells in the biofilm-air interface as a citrate complex, and then transported out and bound by out membranes of cells, released from the copper-bound membranes, and finally precipitated with phosphate in the extracellular matrix of the biofilm. These results revealed a clear spatial pattern of copper precipitation in unsaturated biofilm, which was responsible for the high copper tolerance and accumulation of the biofilm.

  7. An evaluation of the accumulation of intracellular inorganic nitrogen pools by marine microalgae in batch cultures

    Directory of Open Access Journals (Sweden)

    Paris L. Lavín

    2005-06-01

    Full Text Available Methods of extraction, changes in concentrations with growth, and effects of culture conditions on intracellular inorganic nitrogen pools (IIN - ammonia, nitrite, and nitrate were studied in nine species of marine microalgae in batch cultures. The microalgae were analysed to compare three methods of extraction of IIN, one of them developed in this study. The extraction of IIN occurs efficient by with all three methods for four out of the nine species tested. However, for five species significant differences were found among the methods, the best results being obtained with the new method. Microalgae accumulate inorganic forms of nitrogen in different proportions. The species show higher concentrations of either ammonia or nitrate, and always lower concentrations of nitrite. Microalgae of smaller cellular volumes tend to attain higher values of IIN per cubic micrometer (the converse in large-volume species, with some exceptions (Amphidinium carterae and Nannochloropsis oculata. The use of aeration in the cultures determines a decrease in the concentrations of IIN, favours nitrogen assimilation, and generates an increase in growth rates and C:N ratio. High concentrations of IIN are characteristic of the exponential growth phase, but in some cases their occurrence may result from carbon deficiency.Métodos de extração, mudanças na concentração durante o crescimento e efeitos de condições de cultivo sobre conteúdos de nitrogênio inorgânico intracelular (NII - amônia, nitrito e nitrato foram estudados em nove espécies de microalgas marinhas em cultivos estanques. As microalgas foram analisadas para comparar três métodos de extração de NII, um dos quais desenvolvido neste estudo. A extração de NII ocorre de forma eficiente com os três métodos para quatro espécies. Contudo, para cinco espécies diferenças significativas foram encontradas e os melhores resultados foram obtidos com o método novo. As microalgas acumulam formas inorg

  8. [Combined effects of copper and simulated acid rain on copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa].

    Science.gov (United States)

    He, Shan-Ying; Gao, Yong-Jie; Shentu, Jia-Li; Chen, Kun-Bai

    2011-02-01

    A pot experiment was conducted to study the combined effects of Cu (0-1500 mg x kg(-1)) and simulated acid rain (pH 2.5-5.6) on the copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa. With the increasing concentration of soil Cu, the Cu accumulation in R. acetosa increased, being higher in root than in stem and leaf. The exposure to low pH acid rain promoted the Cu uptake by R. acetosa. With the increase of soil Cu concentration and/or of acid rain acidity, the biomass of R. acetosa decreased, leaf and root MDA contents increased and had good correlation with soil Cu concentration, and the SOD and POD activities in leaf and root displayed a decreasing trend after an initial increase. This study showed that R. acetosa had a strong adaptive ability to Cu and acid rain stress, exhibiting a high application potential in the remediation of Cu-contaminated soil in acid rain areas.

  9. Inter-population comparisons of copper resistance and accumulation in the red seaweed, Gracilariopsis longissima.

    Science.gov (United States)

    Brown, Murray T; Newman, James E; Han, Taejun

    2012-03-01

    Copper (Cu) resistance and accumulation of five populations of the red seaweed Gracilariopsis longissima collected from sites in south west England (Fal Estuary, Helford Estuary and Chesil Fleet) that differ in their degree of Cu contamination was assessed under controlled laboratory conditions, on two separate occasions (April and October). The effects of a range of Cu concentrations (0-250 μg l(-1)) on relative growth rates was the same for all populations with reductions observable at concentrations as low as 12 μg l(-1) and cessation of growth at 250 μg l(-1). There was no significant difference in the calculated EC(50) values for the April and October samples, with means of 31.1 and 25.8 μg l(-1), respectively. Over the range of concentrations used in this study, copper content increased linearly and the pattern of accumulation was the same for all populations at both time periods. From the linear regressions of the pooled data a concentration factor of 2.25 × 10(3) was calculated. These results imply that G. longissima has an innate tolerance to Cu and that populations have not evolved copper-tolerant ecotypes. In laboratory studies, accumulated Cu was released when transferred to 'clean' seawater with approximately 80% being lost after 8 days, with no significant difference between populations in their response. The results from a 30 days in situ transplantation experiment using two populations from the Fal Estuary provided further evidence for dynamic changes in Cu content in response to changes in Cu bioavailability. The findings in this study are discussed in the context of implications for seaweed biomonitoring.

  10. Assessing the effect of copper on growth, copper accumulation and physiological responses of grazing species Atriplex halimus: ecotoxicological implications.

    Science.gov (United States)

    Mateos-Naranjo, E; Andrades-Moreno, L; Cambrollé, J; Perez-Martin, A

    2013-04-01

    Tolerance of plants to elevated concentrations of heavy metals in growth media and in its tissues leads to high degrees of metal bioaccumulation, which may pose a risk for humans and animals alike. Therefore, bio-accumulating plants need thorough evaluation from an environmental health point of view. A glasshouse experiment concerning the xerohalophyte Atriplex halimus was carried out to determine its tolerance and capacity to accumulate copper. We investigated the effect of Cu from 0 to 30 mmol l(-1) on the growth, photosynthetic apparatus and nutrient uptake of A. halimus by measuring gas exchange, chlorophyll fluorescence and photoinhibition. We also determined total Cu, sodium, potassium, magnesium, phosphorous, and nitrogen content in the plant. Our results indicated that A. halimus presented a high resistance to Cu-induced stress, since the plants were able to survive at concentrations higher than 15 mmol l(-1) Cu. However, this capacity was not reflected in its ability to accumulate and tolerate greater amounts of Cu in its tissues, since clear phytotoxicity symptoms were detected at tissue concentrations greater than 38 mg kg(-1) Cu. Thus, Cu increment caused a reduction in A. halimus growth, which was related to a decrease in net photosynthetic rate. This reduction was associated with the adverse effect of Cu on the photochemical apparatus and the reduction in the absorption of essential nutrients. The high resistance of A. halimus was largely related with the capacity of this species to avoid the absorption of great amounts of Cu. For all the above reasons, A. halimus could have the characteristics of a Cu-exclusion plant. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Cross talk between increased intracellular zinc (Zn2+) and accumulation of reactive oxygen species in chemical ischemia.

    Science.gov (United States)

    Slepchenko, Kira G; Lu, Qiping; Li, Yang V

    2017-10-01

    Both zinc (Zn 2+ ) and reactive oxygen species (ROS) have been shown to accumulate during hypoxic-ischemic stress and play important roles in pathological processes. To understand the cross talk between the two of them, here we studied Zn 2+ and ROS accumulation by employing fluorescent probes in HeLa cells to further the understanding of the cause and effect relationship of these two important cellular signaling systems during chemical-ischemia, stimulated by oxygen and glucose deprivation (OGD). We observed two Zn 2+ rises that were divided into four phases in the course of 30 min of OGD. The first Zn 2+ rise was a transient, which was followed by a latent phase during which Zn 2+ levels recovered; however, levels remained above a basal level in most cells. The final phase was the second Zn 2+ rise, which reached a sustained plateau called Zn 2+ overload. Zn 2+ rises were not observed when Zn 2+ was removed by TPEN (a Zn 2+ chelator) or thapsigargin (depleting Zn 2+ from intracellular stores) treatment, indicating that Zn 2+ was from intracellular storage. Damaging mitochondria with FCCP significantly reduced the second Zn 2+ rise, indicating that the mitochondrial Zn 2+ accumulation contributes to Zn 2+ overload. We also detected two OGD-induced ROS rises. Two Zn 2+ rises preceded two ROS rises. Removal of Zn 2+ reduced or delayed OGD- and FCCP-induced ROS generation, indicating that Zn 2+ contributes to mitochondrial ROS generation. There was a Zn 2+ -induced increase in the functional component of NADPH oxidase, p47 phox , thus suggesting that NADPH oxidase may mediate Zn 2+ -induced ROS accumulation. We suggest a new mechanism of cross talk between Zn 2+ and mitochondrial ROS through positive feedback processes that eventually causes excessive free Zn 2+ and ROS accumulations during the course of ischemic stress. Copyright © 2017 the American Physiological Society.

  12. Increased extracellular and intracellular Ca{sup 2+} lead to adipocyte accumulation in bone marrow stromal cells by different mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Ryota, E-mail: hryota@juntendo.ac.jp [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Katoh, Youichi, E-mail: katoyo@juntendo-urayasu.jp [Juntendo University Faculty of International Liberal Arts, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Miyamoto, Yuki [Juntendo University Faculty of Health Care and Nursing, Takasu 2-5-1, Urayasu-shi, Chiba 279-0023 (Japan); Itoh, Seigo; Daida, Hiroyuki [Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Nakazato, Yuji [Center for Environmental Research, Department of Cardiology, Juntendo University Faculty of Medicine Urayasu Hospital, Tomioka 2-1-1, Urayasu-shi, Chiba 279-0022 (Japan); Okada, Takao [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2015-02-20

    Mesenchymal stem cells found in bone marrow stromal cells (BMSCs) are the common progenitors for both adipocyte and osteoblast. An increase in marrow adipogenesis is associated with age-related osteopenia and anemia. Both extracellular and intracellular Ca{sup 2+} ([Ca{sup 2+}]{sub o} and [Ca{sup 2+}]{sub i}) are versatile signaling molecules that are involved in the regulation of cell functions, including proliferation and differentiation. We have recently reported that upon treatment of BMSCs with insulin and dexamethasone, both high [Ca{sup 2+}]{sub o} and high [Ca{sup 2+}]{sub i} enhanced adipocyte accumulation, which suggested that increases in [Ca{sup 2+}]{sub o} caused by bone resorption may accelerate adipocyte accumulation in aging and diabetic patients. In this study, we used primary mouse BMSCs to investigate the mechanisms by which high [Ca{sup 2+}]{sub o} and high [Ca{sup 2+}]{sub i} may enhance adipocyte accumulation. In the process of adipocyte accumulation, two important keys are adipocyte differentiation and the proliferation of BMSCs, which have the potential to differentiate into adipocytes. Use of MTT assay and real-time RT-PCR revealed that high [Ca{sup 2+}]{sub i} (ionomycin)-dependent adipocyte accumulation is caused by enhanced proliferation of BMSCs but not enhanced differentiation into adipocytes. Using fura-2 fluorescence-based approaches, we showed that high [Ca{sup 2+}]{sub o} (addition of CaCl{sub 2}) leads to increases in [Ca{sup 2+}]{sub i}. Flow cytometric methods revealed that high [Ca{sup 2+}]{sub o} suppressed the phosphorylation of ERK independently of intracellular Ca{sup 2+}. The inhibition of ERK by U0126 and PD0325901 enhanced the differentiation of BMSCs into adipocytes. These data suggest that increased extracellular Ca{sup 2+} provides the differentiation of BMSCs into adipocytes by the suppression of ERK activity independently of increased intracellular Ca{sup 2+}, which results in BMSC proliferation. - Highlights:

  13. Acute Lethal Toxicity and Accumulation of Copper in Gammarus pulex (L.) (Amphipoda)

    OpenAIRE

    GÜVEN, Kemal; ÖZBAY, Cengizhan; ÜNLÜ, Erhan; SATAR, Ali

    1999-01-01

    Gammarus pulex (L.) collected from clean sites around Kabakli pond (Diyarbakır) was acclimatized at 15°C for 10 days. The individuals were placed in 1lt. vessels and exposed to Cu ++ concentrations of 0.05, 0.08, 0.10, 0.15, 0.20, 0.30 and 0.50 ppm to determine both 24, 48, 72 and 96 h LC50 values and Cu ++ accumulation over 96h. LC 50 values at 24, 48, 72 and 96 h were calculated to be 0.2, 0.17, 0.12 and 0.1 ppm, respectively. Acute copper accumulation in gammarids exposed to various c...

  14. Ultrafine-Grained Precipitation Hardened Copper Alloys by Swaging or Accumulative Roll Bonding

    Directory of Open Access Journals (Sweden)

    Igor Altenberger

    2015-05-01

    Full Text Available There is an increasing demand in the industry for conductive high strength copper alloys. Traditionally, alloy systems capable of precipitation hardening have been the first choice for electromechanical connector materials. Recently, ultrafine-grained materials have gained enormous attention in the materials science community as well as in first industrial applications (see, for instance, proceedings of NANO SPD conferences. In this study the potential of precipitation hardened ultra-fine grained copper alloys is outlined and discussed. For this purpose, swaging or accumulative roll-bonding is applied to typical precipitation hardened high-strength copper alloys such as Corson alloys. A detailed description of the microstructure is given by means of EBSD, Electron Channeling Imaging (ECCI methods and consequences for mechanical properties (tensile strength as well as fatigue and electrical conductivity are discussed. Finally the role of precipitates for thermal stability is investigated and promising concepts (e.g. tailoring of stacking fault energy for grain size reduction and alloy systems for the future are proposed and discussed. The relation between electrical conductivity and strength is reported.

  15. Bio-accumulation of copper, zinc, iron and manganese in oyster Saccostrea cucullata, Snail Cerithium rubus and Clam Tellina angulata from the Bombay coast

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Nair, V.R.; Moraes, C.

    accumulation was high in S. cucullata, manganese in C. rubus and iron in T. angulata. Similarly, copper and zinc in S. cucullata and copper in C. rubus were found occasionally higher than accepted health standards...

  16. An atmospheric-pressure cold plasma leads to apoptosis in Saccharomyces cerevisiae by accumulating intracellular reactive oxygen species and calcium

    Science.gov (United States)

    Ma, R. N.; Feng, H. Q.; Liang, Y. D.; Zhang, Q.; Tian, Y.; Su, B.; Zhang, J.; Fang, J.

    2013-07-01

    A non-thermal plasma is known to induce apoptosis of various cells but the mechanism is not yet clear. A eukaryotic model organism Saccharomyces cerevisiaewas used to investigate the cellular and biochemical regulations of cell apoptosis and cell cycle after an atmospheric-pressure cold plasma treatment. More importantly, intracellular calcium (Ca2+) was first involved in monitoring the process of plasma-induced apoptosis in this study. We analysed the cell apoptosis and cell cycle by flow cytometry and observed the changes in intracellular reactive oxygen species (ROS) and Ca2+ concentration, cell mitochondrial membrane potential (Δψm) as well as nuclear DNA morphology via fluorescence staining assay. All experimental results indicated that plasma-generated ROS leads to the accumulation of intracellular ROS and Ca2+ that ultimately contribute to apoptosis associated with cell cycle arrest at G1 phase through depolarization of Δψm and fragmenting nuclear DNA. This work provides a novel insight into the physical and biological mechanism of apoptosis induced by a plasma which could benefit for promoting the development of plasmas applied to cancer therapy.

  17. An Extended Model for Tracking Accumulation Pathways of Materials Using Input–Output Tables: Application to Copper Flows in Japan

    Directory of Open Access Journals (Sweden)

    Ryosuke Yokoi

    2018-03-01

    Full Text Available Recycling has become increasingly important as a means to mitigate not only waste issues but also problems related to primary resource use, such as a decrease in resource availability. In order to promote and plan future recycling efficiently, detailed information on the material stock in society is important. For a detailed analysis of material stocks, quantitative information on flows of a material, such as its accumulation pathways, final destinations, and its processing forms, are required. This paper develops a model for tracking accumulation pathways of materials using input–output tables (IOTs. The main characteristics of the proposed model are as follows: (1 accumulations in sectors other than the final demand sectors (i.e., endogenous sectors are explicitly evaluated, (2 accumulations as accompaniments to products, such as containers and packaging, are distinguished from the products, and (3 processing forms of materials are considered. The developed model is applied to analyze copper flows in Japan using the Japanese IOTs for the year 2011. The results show that accumulations of copper in endogenous sectors were not negligibly small (9.24% of the overall flow. Although accumulations of copper as accompaniments were very small, they may be larger for other materials that are largely used as containers or packaging. It was found that the destinations of copper showed different characteristics depending on the processing forms.

  18. Carbon black nanoparticles promote endothelial activation and lipid accumulation in macrophages independently of intracellular ROS production

    DEFF Research Database (Denmark)

    Cao, Yi; Roursgaard, Martin; Danielsen, Pernille Høgh

    2014-01-01

    black (CB) exposure in cultured human umbilical vein endothelial cells (HUVECs), THP-1 (monocytes) and THP-1 derived macrophages (THP-1a). The proliferation of HUVECs or co-cultures of HUVECs and THP-1 cells were unaffected by CB exposure, whereas there was increased cytotoxicity, assessed by the LDH...... and WST-1 assays, especially in THP-1 and THP-1a cells. The CB exposure decreased the glutathione (GSH) content in THP-1 and THP-1a cells, whereas GSH was increased in HUVECs. The reactive oxygen species (ROS) production was increased in all cell types after CB exposure. A reduction of the intracellular...... GSH concentration by buthionine sulfoximine (BSO) pre-treatment further increased the CB-induced ROS production in THP-1 cells and HUVECs. The expression of adhesion molecules ICAM-1 and VCAM-1, but not adhesion of THP-1 to HUVECs or culture dishes, was elevated by CB exposure, whereas these effects...

  19. Copper accumulation in vineyard soils: Rhizosphere processes and agronomic practices to limit its toxicity.

    Science.gov (United States)

    Brunetto, Gustavo; Bastos de Melo, George Wellington; Terzano, Roberto; Del Buono, Daniele; Astolfi, Stefania; Tomasi, Nicola; Pii, Youry; Mimmo, Tanja; Cesco, Stefano

    2016-11-01

    Viticulture represents an important agricultural practice in many countries worldwide. Yet, the continuous use of fungicides has caused copper (Cu) accumulation in soils, which represent a major environmental and toxicological concern. Despite being an important micronutrient, Cu can be a potential toxicant at high concentrations since it may cause morphological, anatomical and physiological changes in plants, decreasing both food productivity and quality. Rhizosphere processes can, however, actively control the uptake and translocation of Cu in plants. In particular, root exudates affecting the chemical, physical and biological characteristics of the rhizosphere, might reduce the availability of Cu in the soil and hence its absorption. In addition, this review will aim at discussing the advantages and disadvantages of agronomic practices, such as liming, the use of pesticides, the application of organic matter, biochar and coal fly ashes, the inoculation with bacteria and/or mycorrhizal fungi and the intercropping, in alleviating Cu toxicity symptoms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Stabilized copper plating method by programmed electroplated current: Accumulation of densely packed copper grains in the interconnect

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Li-Chi; Hsu, Li-Hsuan; Brahma, Sanjaya; Huang, Bo-Chia; Liu, Chun-Chu; Lo, Kuang-Yao, E-mail: kuanglo@mail.ncku.edu.tw

    2016-12-01

    Highlights: • Actual Cu interconnect experiences many times of annealing and then cause the stress. • Stack Cu grains with varying grain size successively to enhance packed density. • XRD and PBR analyze the residual stress of local and average area of plated Cu film. • High packed Cu grain with stable stress proved by texture of Cu(1 1 1) and Cu(2 0 0). - Abstract: In this work, we programmed the plating current to stack the different size of copper (Cu) grain and analyzed the relation between the sequence of different Cu grain size and the stability of the residual stress. The residual stress was measured with varying times of annealing process in order to reach the purpose of simulating the actual Cu interconnect process. We found that varied plating strategy will make different stabilization condition of residual stress through the proof of X-ray diffraction (XRD) and optical parallel beams reflection (PBR) method. The accumulation of Cu grains, formed by Cu grain with successive variation in grain size, would enhance the packing density better than only single grain size in the finite space. The high density of the grain boundary in the electroplated Cu film will be eliminated through annealing process and it will help to suppress the void formation in further interconnect process. The electroplated Cu film with the plating current of saw tooth wave can soon reach a stable tensile stress through annealing since the Cu grains with high packing density will be quickly eliminated to approach the minimum of the strain energy which reflects to variation in the texture of Cu (2 0 0). The result of this work illustrates the importance of how to stack different size of Cu grain, for achieving a densely packed Cu film which close to the Cu bulk.

  1. Copper use and accumulation in catfish culture in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Marcussen, Helle; Løjmand, Helle; Dalsgaard, Anders; Hai, Dao M; Holm, Peter E

    2014-01-01

    Aquaculture of Pangasius hypophthalmus (striped catfish) in Vietnam reached 1.1 million tonnes in 2011 and catfish fillets are exported worldwide. The intensive cultures of catfish mainly in earth ponds have made it necessary to apply CuSO4 and other chemicals to control external parasites and other pathogens. However, accumulation of Cu in aquaculture ponds may pose a hazard to growth of fish or to the aquatic environment. The aim of this study was to determine accumulation of Cu in sediment, water and fish in a catfish pond with a history of repeated treatment with CuSO4 in the Mekong Delta, Vietnam. Copper concentrations in pond sediment were in the interval 21.3-45.7 mg kg(-1) dw and did not exceed the Vietnamese values for soil to be used for agricultural production (70 mg kg(-1) dw.). During three samplings the total mean concentration of Cu in pond water (4 μg L(-1)) did not exceed the LC50-value (70 μg L(-1)) for catfish and the mean dissolved concentration of Cu (0.986 μg L(-1)) did not seem to constitute a risk for the stability of the aquatic ecosystem. No significant variation in Cu concentrations between sampling sites in the pond and depth of sediment profile were determined. The accumulation of Cu in catfish was highest in the liver compared to the skin, gills and muscle tissue. With the current practice of removing pond sludge three to four times during a production cycle little if any Cu seems to accumulate in catfish ponds despite repeated anti-parasite treatments with CuSO4. Further studies are needed to assess the eco-toxicity and impact on agricultural production when pond sediment is discharged into aquatic recipients and used as soil fertilizer.

  2. Inhibition of P-glycoprotein by HIV protease inhibitors increases intracellular accumulation of berberine in murine and human macrophages.

    Directory of Open Access Journals (Sweden)

    Weibin Zha

    Full Text Available HIV protease inhibitor (PI-induced inflammatory response in macrophages is a major risk factor for cardiovascular diseases. We have previously reported that berberine (BBR, a traditional herbal medicine, prevents HIV PI-induced inflammatory response through inhibiting endoplasmic reticulum (ER stress in macrophages. We also found that HIV PIs significantly increased the intracellular concentrations of BBR in macrophages. However, the underlying mechanisms of HIV PI-induced BBR accumulation are unknown. This study examined the role of P-glycoprotein (P-gp in HIV PI-mediated accumulation of BBR in macrophages.Cultured mouse RAW264.7 macrophages, human THP-1-derived macrophages, Wild type MDCK (MDCK/WT and human P-gp transfected (MDCK/P-gp cells were used in this study. The intracellular concentration of BBR was determined by HPLC. The activity of P-gp was assessed by measuring digoxin and rhodamine 123 (Rh123 efflux. The interaction between P-gp and BBR or HIV PIs was predicated by Glide docking using Schrodinger program. The results indicate that P-gp contributed to the efflux of BBR in macrophages. HIV PIs significantly increased BBR concentrations in macrophages; however, BBR did not alter cellular HIV PI concentrations. Although HIV PIs did not affect P-gp expression, P-gp transport activities were significantly inhibited in HIV PI-treated macrophages. Furthermore, the molecular docking study suggests that both HIV PIs and BBR fit the binding pocket of P-gp, and HIV PIs may compete with BBR to bind P-gp.HIV PIs increase the concentration of BBR by modulating the transport activity of P-gp in macrophages. Understanding the cellular mechanisms of potential drug-drug interactions is critical prior to applying successful combinational therapy in the clinic.

  3. Effect of organic complexation on copper accumulation and toxicity to the estuarine red macroalga Ceramium tenuicorne: a test of the free ion activity model.

    Science.gov (United States)

    Ytreberg, Erik; Karlsson, Jenny; Hoppe, Sabina; Eklund, Britta; Ndungu, Kuria

    2011-04-01

    Current water quality criteria (WQC) regulations on copper toxicity to biota are still based on total dissolved (copper concentrations with a hardness modification for freshwaters. There are however ongoing efforts to incorporate metal speciation in WQC and toxicity regulations (such as the biotic ligand model-BLM) for copper and other metals. Here, we show that copper accumulation and growth inhibition of the Baltic macroalga Ceramium tenuicorne exposed to copper in artificial seawater at typical coastal and estuarine DOC concentrations (similar to 2-4 mg/L-C as fulvic acid) are better correlated to weakly complexed and total dissolved copper concentrations rather than the free copper concentration [Cu2+]. Our results using a combination of competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV) measurements and model calculations (using visual MINTEQ incorporating the Stockholm Humic Model) show that copper accumulation in C. tenuicorne only correlates linearly well to [Cu2+] at relatively high [Cu2+] and in the absence of fulvic acid. Thus the FIAM fails to describe copper accumulation in C. tenuicorne at copper and DOC concentrations typical of most marine waters. These results seem to indicate that at ambient total dissolved copper concentration in coastal and estuarine waters, C. tenuicorne might be able to access a sizable fraction of organically complexed copper when free copper concentration to the cell membrane is diffusion limited.

  4. Copper accumulation in the sequestrum of medication-related osteonecrosis of the jaw

    Directory of Open Access Journals (Sweden)

    Tomoko Sugiyama

    2015-12-01

    Full Text Available Bisphosphonates (BPs have been widely, efficiently, and safely used for the treatment of various bone-related diseases such as osteoporosis. However, concerns about jaw osteonecrosis associated with oral treatment (medication-related osteonecrosis of the jaw [MRONJ] have been increasing. Although many risk factors for MRONJ have been elucidated, its precise etiology and methods of prevention remain unknown. In this study, we have applied various elemental analysis methods for MRONJ specimens (e.g., X-ray fluorescence with synchrotron radiation [SR-XRF], particle-induced X-ray emission [PIXE], X-ray absorption fine structure [XAFS] in order to reveal the accumulation and chemical state of trace bone minerals. In four MRONJ sequestra, the characteristic localization of copper (Cu was observed by SR-XRF. Using micro-PIXE analysis, Cu looked to be localized near the edge of the trabecular bone. The chemical state of the accumulated Cu was estimated using XAFS and the possibility of a Cu–BP complex formation was assumed. Thus, in this study we argue for the feasibility of the trace element analysis to evaluate the potential pathophysiological mechanism of MRONJ.

  5. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Science.gov (United States)

    Fu, Lei; Chen, Chen; Wang, Bin; Zhou, Xishi; Li, Shuhuan; Guo, Pan; Shen, Zhenguo; Wang, Guiping; Chen, Yahua

    2015-01-01

    Differences in copper (Cu) absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type) and Elsholtzia haichowensis (Cu-enrichment type), were investigated in the present study. The results indicated the following: (1) After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2) An analysis of the endogenous abscisic acid (ABA) variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3) The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4) The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  6. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Directory of Open Access Journals (Sweden)

    Lei Fu

    Full Text Available Differences in copper (Cu absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type and Elsholtzia haichowensis (Cu-enrichment type, were investigated in the present study. The results indicated the following: (1 After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2 An analysis of the endogenous abscisic acid (ABA variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3 The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4 The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  7. Mercury-Pollution Induction of Intracellular Lipid Accumulation and Lysosomal Compartment Amplification in the Benthic Foraminifer Ammonia parkinsoniana.

    Directory of Open Access Journals (Sweden)

    Fabrizio Frontalini

    Full Text Available Heavy metals such as mercury (Hg pose a significant health hazard through bioaccumulation and biomagnification. By penetrating cell membranes, heavy metal ions may lead to pathological conditions. Here we examined the responses of Ammonia parkinsoniana, a benthic foraminiferan, to different concentrations of Hg in the artificial sea water. Confocal images of untreated and treated specimens using fluorescent probes (Nile Red and Acridine Orange provided an opportunity for visualizing the intracellular lipid accumulation and acidic compartment regulation. With increased Hg over time, we observed an increased number of lipid droplets, which may have acted as a detoxifying organelle where Hg is sequestered and biologically inactivated. Further, Hg seems to promote the proliferation of lysosomes both in terms of number and dimension that, at the highest level of Hg, resulted in cell death. We report, for the first time, the presence of Hg within the foraminiferal cell: at the basal part of pores, in the organic linings of the foramen/septa, and as cytoplasmic accumulations.

  8. Role of ATP-binding cassette and solute carrier transporters in erlotinib CNS penetration and intracellular accumulation.

    Science.gov (United States)

    Elmeliegy, Mohamed A; Carcaboso, Angel M; Tagen, Michael; Bai, Feng; Stewart, Clinton F

    2011-01-01

    To study the role of drug transporters in central nervous system (CNS) penetration and cellular accumulation of erlotinib and its metabolite, OSI-420. After oral erlotinib administration to wild-type and ATP-binding cassette (ABC) transporter-knockout mice (Mdr1a/b(-/-), Abcg2(-/-), Mdr1a/b(-/-)Abcg2(-/-), and Abcc4(-/-)), plasma was collected and brain extracellular fluid (ECF) was sampled using intracerebral microdialysis. A pharmacokinetic model was fit to erlotinib and OSI-420 concentration-time data, and brain penetration (P(Brain)) was estimated by the ratio of ECF-to-unbound plasma area under concentration-time curves. Intracellular accumulation of erlotinib was assessed in cells overexpressing human ABC transporters or SLC22A solute carriers. P(Brain) in wild-type mice was 0.27 ± 0.11 and 0.07 ± 0.02 (mean ± SD) for erlotinib and OSI-420, respectively. Erlotinib and OSI-420 P(Brain) in Abcg2(-/-) and Mdr1a/b(-/-)Abcg2(-/-) mice were significantly higher than in wild-type mice. Mdr1a/b(-/-) mice showed similar brain ECF penetration as wild-type mice (0.49 ± 0.37 and 0.04 ± 0.02 for erlotinib and OSI-420, respectively). In vitro, erlotinib and OSI-420 accumulation was significantly lower in cells overexpressing breast cancer resistance protein (BCRP) than in control cells. Only OSI-420, not erlotinib, showed lower accumulation in cells overexpressing P-glycoprotein (P-gp) than in control cells. The P-gp/BCRP inhibitor elacridar increased erlotinib and OSI-420 accumulation in BCRP-overexpressing cells. Erlotinib uptake was higher in OAT3- and OCT2-transfected cells than in empty vector control cells. Abcg2 is the main efflux transporter preventing erlotinib and OSI-420 penetration in mouse brain. Erlotinib and OSI-420 are substrates for SLC22A family members OAT3 and OCT2. Our findings provide a mechanistic basis for erlotinib CNS penetration, cellular uptake, and efflux mechanisms. ©2010 AACR.

  9. Fate, accumulation and ecotoxicity of copper nanoparticles under environmentally relevant conditions

    NARCIS (Netherlands)

    Xiao, Y.

    2017-01-01

    Fate and toxicity of copper nanoparticles was related to the water chemistry of the environment and pristine size. Connection between fate and toxicity of copper nanoparticles could be drawn. The particle-specific toxicity of copper nanoparticles was dependent on water chemistry.

  10. Inhibition of the Mitochondrial Glutamate Carrier SLC25A22 in Astrocytes Leads to Intracellular Glutamate Accumulation

    Directory of Open Access Journals (Sweden)

    Emmanuelle Goubert

    2017-05-01

    Full Text Available The solute carrier family 25 (SLC25 drives the import of a large diversity of metabolites into mitochondria, a key cellular structure involved in many metabolic functions. Mutations of the mitochondrial glutamate carrier SLC25A22 (also named GC1 have been identified in early epileptic encephalopathy (EEE and migrating partial seizures in infancy (MPSI but the pathophysiological mechanism of GC1 deficiency is still unknown, hampered by the absence of an in vivo model. This carrier is mainly expressed in astrocytes and is the principal gate for glutamate entry into mitochondria. A sufficient supply of energy is essential for the proper function of the brain and mitochondria have a pivotal role in maintaining energy homeostasis. In this work, we wanted to study the consequences of GC1 absence in an in vitro model in order to understand if glutamate catabolism and/or mitochondrial function could be affected. First, short hairpin RNA (shRNA designed to specifically silence GC1 were validated in rat C6 glioma cells. Silencing GC1 in C6 resulted in a reduction of the GC1 mRNA combined with a decrease of the mitochondrial glutamate carrier activity. Then, primary astrocyte cultures were prepared and transfected with shRNA-GC1 or mismatch-RNA (mmRNA constructs using the Neon® Transfection System in order to target a high number of primary astrocytes, more than 64%. Silencing GC1 in primary astrocytes resulted in a reduced nicotinamide adenine dinucleotide (Phosphate (NAD(PH formation upon glutamate stimulation. We also observed that the mitochondrial respiratory chain (MRC was functional after glucose stimulation but not activated by glutamate, resulting in a lower level of cellular adenosine triphosphate (ATP in silenced astrocytes compared to control cells. Moreover, GC1 inactivation resulted in an intracellular glutamate accumulation. Our results show that mitochondrial glutamate transport via GC1 is important in sustaining glutamate homeostasis in

  11. Two Outer Membrane Proteins Contribute to Caulobacter crescentus Cellular Fitness by Preventing Intracellular S-Layer Protein Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Overton, K. Wesley; Park, Dan M.; Yung, Mimi C.; Dohnalkova, Alice; Smit, John; Jiao, Yongqin

    2016-09-23

    ABSTRACT

    Surface layers, or S-layers, are two-dimensional protein arrays that form the outermost layer of many bacteria and archaea. They serve several functions, including physical protection of the cell from environmental threats. The high abundance of S-layer proteins necessitates a highly efficient export mechanism to transport the S-layer protein from the cytoplasm to the cell exterior.Caulobacter crescentusis unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaFaand RsaFb, which together with other components form a type I protein translocation pathway for S-layer export. These proteins have homology toEscherichia coliTolC, the outer membrane channel of multidrug efflux pumps. Here we provide evidence that, unlike TolC, RsaFaand RsaFbare not involved in either the maintenance of membrane stability or the active export of antimicrobial compounds. Rather, RsaFaand RsaFbare required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaFaand RsaFbled to a general growth defect and lowered cellular fitness. Using Western blotting, transmission electron microscopy, and transcriptome sequencing (RNA-seq), we show that loss of both RsaFaand RsaFbled to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein misfolding and degradation pathways. These findings provide new insight into the requirement for RsaFaand RsaFbin cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels in

  12. Intracellular heavy metal nanoparticle storage: progressive accumulation within lymph nodes with transformation from chronic inflammation to malignancy

    Directory of Open Access Journals (Sweden)

    Tommaso Iannitti

    2010-11-01

    Full Text Available Tommaso Iannitti1, Stefania Capone2, Antonietta Gatti3, Frederico Capitani4, Cetta Francesco5,6, Beniamino Palmieri21Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK; 2Department of General Surgery and Surgical Specialties, 3Laboratory of Biomaterials, Department of Specialistic Surgeries, Head and Neck Medical School and Surgical Clinic, University of Modena and Reggio Emilia, Italy; 4Laboratory of Nanodiagnostics, San Vito, Modena, Italy 5Department of Surgery, University of Siena, Siena; 6Institute of Geriatrics, Pio Albergo Trivulzio Hospital, Milan, ItalyAbstract: A 25-year-old man had complained of sudden fever spikes for two years and his blood tests were within the normal range. In 1993, a surgical biopsy of swollen left inguinal lymph nodes was negative for malignancy, but showed reactive lymphadenitis and widespread sinus histiocytosis. A concomitant needle biopsy of the periaortic lymph nodes and a bone marrow aspirate were also negative. In 1994, after an emergency hospital admission because of a sport-related thoracic trauma, a right inguinal lymph node biopsy demonstrated Hodgkin’s lymphoma Stage IVB (scleronodular mixed cell subtype. Although it was improved by chemotherapy, the disease suddenly relapsed, and a further lymph node biopsy was performed in 1998 confirming the same diagnosis. Despite further treatment, the patient died of septic shock in 2004, at the age of 38 years. Retrospective analysis of the various specimens showed intracellular heavy metal nanoparticles within lymph node, bone marrow, and liver samples by field emission gun environmental scanning electron microscopy and energy dispersive spectroscopy. Heavy metals from environmental pollution may accumulate in sites far from the entry route and, in genetically conditioned individuals with tissue specificity, may act as cofactors for chronic inflammation or even malignant transformation. The present anecdotal report

  13. Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhu [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu, Longhua, E-mail: lhwu@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Hu, Pengjie [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Yongming [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yantai Institute of Coastal Zone Research, Yantai 264003 (China); Christie, Peter [Agri-Environment Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom)

    2013-10-15

    Highlights: • Low Cu has no significant effect on Sedum plumbizincicola plant growth and Cd and Zn uptake. • Plant held Cu in unactive areas and insoluble forms as de-toxification mechanisms. • Influence of Cu on Zn and Cd uptake and translocation were different. • Cu accumulation in leaf veins may restrain Cd/Zn unloading to the leaves -- Abstract: Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31 μM Cu), 5–50 μM Cu had no significant effect on Cd/Zn accumulation, but Cu at 200 μM induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200 μM Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola.

  14. Plant polyphenol induced cell death in human cancer cells involves mobilization of intracellular copper ions and reactive oxygen species generation: a mechanism for cancer chemopreventive action.

    Science.gov (United States)

    Khan, Husain Yar; Zubair, Haseeb; Faisal, Mohd; Ullah, Mohd Fahad; Farhan, Mohd; Sarkar, Fazlul H; Ahmad, Aamir; Hadi, Sheikh Mumtaz

    2014-03-01

    Anticancer polyphenolic nutraceuticals from fruits, vegetables, and spices are generally recognized as antioxidants, but can be prooxidants in the presence of copper ions. We earlier proposed a mechanism for such activity of polyphenols and now we provide data in multiple cancer cell lines in support of our hypothesis. Through multiple assays, we show that polyphenols luteolin, apigenin, epigallocatechin-3-gallate, and resveratrol are able to inhibit cell proliferation and induce apoptosis in different cancer cell lines. Such cell death is prevented to a significant extent by cuprous chelator neocuproine and reactive oxygen species scavengers. We also show that normal breast epithelial cells, cultured in a medium supplemented with copper, become sensitized to polyphenol-induced growth inhibition. Since the concentration of copper is significantly elevated in cancer cells, our results strengthen the idea that an important anticancer mechanism of plant polyphenols is mediated through intracellular copper mobilization and reactive oxygen species generation leading to cancer cell death. Moreover, this prooxidant chemopreventive mechanism appears to be a mechanism common to several polyphenols with diverse chemical structures and explains the preferential cytotoxicity of these compounds toward cancer cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Accumulation of lead, zinc, copper and cadmium by 12 wetland plant species thriving in metal-contaminated sites in China

    International Nuclear Information System (INIS)

    Deng, H.; Ye, Z.H.; Wong, M.H.

    2004-01-01

    The concentrations of lead, zinc, copper and cadmium accumulated by 12 emergent-rooted wetland plant species including different populations of Leersia hexandra, Juncus effusus and Equisetum ramosisti were investigated in field conditions of China. The results showed that metal accumulation by wetland plants differed among species, populations and tissues. Populations grown in substrata with elevated metals contained significantly higher metals in plants. Metals accumulated by wetland plants were mostly distributed in root tissues, suggesting that an exclusion strategy for metal tolerance widely exists in them. That some species/populations could accumulate relatively high metal concentrations (far above the toxic concentration to plants) in their shoots indicates that internal detoxification metal tolerance mechanism(s) are also included. The factors affecting metal accumulation by wetland plants include metal concentrations, pH, and nutrient status in substrata. Mostly concentrations of Pb and Cu in both aboveground and underground tissues of the plants were significantly positively related to their total and/or DTPA-extractable fractions in substrata while negatively to soil N and P, respectively. The potential use of these wetland plants in phytoremediation is also discussed

  16. Accumulation of lead, zinc, copper and cadmium by 12 wetland plant species thriving in metal-contaminated sites in China

    Energy Technology Data Exchange (ETDEWEB)

    Deng, H.; Ye, Z.H.; Wong, M.H

    2004-11-01

    The concentrations of lead, zinc, copper and cadmium accumulated by 12 emergent-rooted wetland plant species including different populations of Leersia hexandra, Juncus effusus and Equisetum ramosisti were investigated in field conditions of China. The results showed that metal accumulation by wetland plants differed among species, populations and tissues. Populations grown in substrata with elevated metals contained significantly higher metals in plants. Metals accumulated by wetland plants were mostly distributed in root tissues, suggesting that an exclusion strategy for metal tolerance widely exists in them. That some species/populations could accumulate relatively high metal concentrations (far above the toxic concentration to plants) in their shoots indicates that internal detoxification metal tolerance mechanism(s) are also included. The factors affecting metal accumulation by wetland plants include metal concentrations, pH, and nutrient status in substrata. Mostly concentrations of Pb and Cu in both aboveground and underground tissues of the plants were significantly positively related to their total and/or DTPA-extractable fractions in substrata while negatively to soil N and P, respectively. The potential use of these wetland plants in phytoremediation is also discussed.

  17. Interactions between accumulated copper, bacterial community structure and histamine levels in crayfish meat during storage.

    NARCIS (Netherlands)

    Soedarini, B.; van Gestel, C.A.M.; van Straalen, N.M.; Widianarko, B.; Roling, W.F.M.

    2014-01-01

    BACKGROUND: Pollution in aquaculture areas may negatively impact edible species and threaten seafood quality and safety. The aim of this study was to determine the interaction between copper and bacteria in the aquatic habitat and their impact upon crustaceans. Marbled crayfish was chosen as a model

  18. Copper transporters and chaperones: Their function on ...

    Indian Academy of Sciences (India)

    2016-08-02

    Aug 2, 2016 ... to be as high as 1500 μg/g dry weight, causing severe morphological and functional changes which include ... Loss of ATP7B activity leads to accumulation of intracellular copper, which in turn leads to increase ... Initially it was reported that neither Cu starvation followed by Cu exposure nor an increase in ...

  19. Distribution and accumulation of mercury and copper in mangrove sediments in Shenzhen, the world's most rapid urbanized city.

    Science.gov (United States)

    Li, Ruili; Xu, Hualin; Chai, Minwei; Qiu, Guo Yu

    2016-02-01

    To investigate the influence of mangrove forest on heavy metal accumulation and storage in intertidal sediments, core sediments from natural mangrove, restored mangrove, and adjacent mud flat spanning the intertidal zone along the south coastline of the most heavily urbanized Deep bay, Guangdong province, China were analyzed. The average concentrations of mercury (Hg) in surface sediments of natural mangrove and restored mangrove were 172 and 151 ng g(-1), whereas those of copper (Cu) were 75 and 50 μg g(-1), respectively. Compared to those from other typical mangrove wetlands of the world, the metal levels in Shenzhen were at median to high levels, which is consistent with the fact that Shenzhen is in high exploitation and its mangrove suffer intensive impact from human activities. Hg and Cu concentration profiles indicated a higher metal accumulation in surface layers of sediments, in agreement with enrichment of organic matter contents. Maximum concentration, enrichment factors, and excess (background-deducted) concentration inventories of metals (Hg and Cu) were substantially different between environments, decreasing from natural mangrove sediments to restored mangrove sediments to mud flat. Furthermore, metal inputs to Futian mangrove decreased in the order natural mangrove > restored mangrove > mud flat, indicating that mangrove facilitated the accumulation and storage of Hg and Cu in sediment layers.

  20. Intracellular accumulation of toxic turn amyloid-β is associated with endoplasmic reticulum stress in Alzheimer's disease.

    Science.gov (United States)

    Soejima, Naoko; Ohyagi, Yasumasa; Nakamura, Norimichi; Himeno, Eri; Iinuma, Kyoko M; Sakae, Nobutaka; Yamasaki, Ryo; Tabira, Takeshi; Murakami, Kazuma; Irie, Kazuhiro; Kinoshita, Noriaki; LaFerla, Frank M; Kiyohara, Yutaka; Iwaki, Toru; Kira, Jun-ichi

    2013-01-01

    Amyloid-β protein (Aβ) accumulates in the neurons of Alzheimer's disease (AD) patients at an early stage of the disease. Recently, we found that Aβ with a toxic turn at positions 22 and 23 accumulates in neurons in AD brain. Here, we studied the accumulation of Aβ, toxic turn Aβ and high-molecular-weight Aβ oligomers in presenilin 1 (PS1) gene-transfected SH-SY5Y cells as well as in the brains of 3xTg-AD mice and AD patients. Immunostaining revealed that accumulation of toxic turn Aβ was promoted in G384A- and I143T-mutant PS1-transfected cells and further enhanced by co-transfection of cells with the Aβ-precursor protein (AβPP) gene. In contrast, accumulation of high-molecular-weight Aβ oligomers was promoted in mutant PS1 cells but attenuated by co-transfection of cells with the AβPP gene. Toxic turn Aβ was detected in the neurons of 3xTg-AD mice aged 2 months, when the mice were cognitively unimpaired. In contrast, high-molecular-weight Aβ oligomers were detected in the neurons of 7-month-old mice, when memory dysfunction is apparent. Furthermore, immunostaining and western blotting for Rab4, Rab6 and GRP78 revealed increased levels of these proteins in mutant PS1 cells and their accumulation in the neurons of 3xTg-AD mice. Remarkably, GRP78 immunoreactivity was increased at 2 months of age. Double-label immunostaining of AD brain revealed an apparent association between toxic turn Aβ and GRP78, an endoplasmic reticulum (ER) stress marker. Intraneuronal accumulation of toxic turn Aβ may be associated with ER stress in the brains of AD model mice and AD patients at an early stage.

  1. Resistance of Streptococcus bovis to acetic acid at low pH: Relationship between intracellular pH and anion accumulation

    International Nuclear Information System (INIS)

    Russell, J.B.

    1991-01-01

    Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grown at pHs from 6.7 to 4.5, and 100 mM acetate had little effect on growth rate or proton motive force across the cell membrane. When S. bovis was grown in glucose-limited chemostats at pH 5.2, the addition of sodium acetate (as much as 100 mM) had little effect on the production of bacterial protein. At higher concentrations of sodium acetate (100 to 360 mM), production of bacterial protein declined, but this decrease could largely be explained by a shift in fermentation products (acetate, formate, and ethanol production to lactate production) and a decline in ATP production (3 ATP per glucose versus 2 ATP per glucose). Y ATP (grams of cells per mole at ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up [ 14 C]acetate and [ 14 C]benzoate in accordance with the Henderson-Hasselbalch equation and gave similar estimates of intracellular pH. As the extracellular pH declined, S. bovis allowed its intracellular pH to decrease and maintained a relatively constant pH gradient across the cell membrane (0.9 unit). The decrease in intracellular pH prevented S. bovis from accumulating large amounts of acetate anion. On the basis of these results it did not appear that acetate was acting as an uncoupler. The sensitivity of other bacteria to volatile fatty acids at low pH is explained most easily by a high transmembrane pH gradient and anion accumulation

  2. Resistance of Streptococcus bovis to acetic acid at low pH: Relationship between intracellular pH and anion accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Russell, J.B. (Cornell Univ., Ithaca, NY (USA))

    1991-01-01

    Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grown at pHs from 6.7 to 4.5, and 100 mM acetate had little effect on growth rate or proton motive force across the cell membrane. When S. bovis was grown in glucose-limited chemostats at pH 5.2, the addition of sodium acetate (as much as 100 mM) had little effect on the production of bacterial protein. At higher concentrations of sodium acetate (100 to 360 mM), production of bacterial protein declined, but this decrease could largely be explained by a shift in fermentation products (acetate, formate, and ethanol production to lactate production) and a decline in ATP production (3 ATP per glucose versus 2 ATP per glucose). Y{sub ATP} (grams of cells per mole at ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up ({sup 14}C)acetate and ({sup 14}C)benzoate in accordance with the Henderson-Hasselbalch equation and gave similar estimates of intracellular pH. As the extracellular pH declined, S. bovis allowed its intracellular pH to decrease and maintained a relatively constant pH gradient across the cell membrane (0.9 unit). The decrease in intracellular pH prevented S. bovis from accumulating large amounts of acetate anion. On the basis of these results it did not appear that acetate was acting as an uncoupler. The sensitivity of other bacteria to volatile fatty acids at low pH is explained most easily by a high transmembrane pH gradient and anion accumulation.

  3. Intracellular accumulation of amyloid-beta - a predictor for synaptic dysfunction and neuron loss in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Thomas A Bayer

    2010-03-01

    Full Text Available Despite of long-standing evidence that beta-amyloid (Aβ peptides have detrimental effects on synaptic function, the relationship between Aβ, synaptic and neuron loss is largely unclear. During the last years there is growing evidence that early intraneuronal accumulation of Aβ peptides is one of the key events leading to synaptic and neuronal dysfunction. Many studies have been carried out using transgenic mouse models of Alzheimer’s disease (AD which have been proven to be valuable model system in modern AD research. The present review discusses the impact of intraneuronal Aβ accumulation on synaptic impairment and neuron loss and provides an overview of currently available AD mouse models showing these pathological alterations.

  4. Accumulative copper poisoning in buffaloes / Intoxicação cúprica acumulativa em búfalos

    Directory of Open Access Journals (Sweden)

    Enrico Lippi Ortolani

    2009-07-01

    Full Text Available The main objective of this study was to evaluate the clinical and hematological alterations, and the hepatic concentration of Cu in buffaloes with chronic copper poisoning (CCP. Ten buffalo yearling steers were randomly distributed into two groups: one copper supplemented (BUFCu; n = 6 and another control group (BUF; n = 4. The group BUFCu received, by ruminal fistula, 2 mg Cu/kgBW (as CuSO4.5H2O daily during one week; after which 2 mg Cu/kgBW was added during each additional week, until the end of the experiment (105th day. Three liver biopsies were realized during the experiment (day zero, 45th, and 105th day to determine the degree of copper accumulation. Alterations in body weight, clinical examination, and hematological values were monitored every 15 days. Two buffaloes supplemented with copper demonstrated clinical manifestations consistent with CCP, and died. Two distinct clinical manifestations were observed, one classical (n = 1 and another atypical (n = 1, characterized by remarkable high levels of liver copper, progressive hyporexia followed by anorexia, dehydration, severe apathy, decreased rumen movements, oliguria, and death. Some animals were resistant to CCP although high copper intake. In buffalos with clinical picture similar to the one described as atypical, CCP should be considered as a possible diagnostic even without presence of macroscopic hemoglobinuria.O presente trabalho objetivou analisar o quadro clínico, variáveis metabólicas e a concentração de cobre nos tecidos de bufalinos submetidos à intoxicação cúprica acumulativa (ICA. Foram utilizados 10 bufalinos jovens, da raça Murrah, aleatoriamente distribuídos em seis animais no grupo suplementado com cobre (BUFCu e quatro no grupo controle (BUF. O grupo BUFCu recebeu suplementação progressiva de cobre através de administração diária de solução aquosa deste microelemento, por meio da fistula ruminal. A dose diária inicial era de 2 mg de Cu/kgPV (CuSO4

  5. Acute toxicity, accumulation and tissue distribution of copper in the blue crab Callinectes sapidus acclimated to different salinities: in vivo and in vitro studies.

    Science.gov (United States)

    Martins, Camila De Martinez Gaspar; Barcarolli, Indianara Fernanda; de Menezes, Eliana Jaime; Giacomin, Marina Mussoi; Wood, Chris M; Bianchini, Adalto

    2011-01-17

    In vivo and in vitro studies were performed to evaluate acute toxicity, organ-specific distribution, and tissue accumulation of copper in Callinectes sapidus acclimated to two different experimental salinities (2 and 30 ppt). Blue crabs were quite tolerant to copper. Acute dissolved copper toxicity (96-h LC(50) and its corresponding 95% confident interval) was higher at salinity 2 ppt (5.3 (3.50-8.05) μM Cu) than at 30 ppt (53.0 (27.39-102.52) μM Cu). The difference between salinities can be completely explained based on the water chemistry because it disappeared when 96-h LC(50) values were expressed as the free Cu(2+) ion (3.1 (1.93-4.95) μM free Cu at 2 ppt versus 5.6 (2.33-13.37) μM free Cu at 30 ppt) or the Cu(2+) activity (1.4 (0.88-2.26) μM Cu activity at 2 ppt versus 1.7 (0.71-4.07) μM Cu activity at 30 ppt). The relationships between gill Cu burden and % mortality were very similar at 2 and 30 ppt, in accord with the Biotic Ligand Model. In vivo experiments showed that copper concentration in the hemolymph is not dependent on metal concentration in the surrounding medium at either experimental salinity. They also showed that copper flux into the gills is higher than into other tissues analyzed, and that anterior and posterior gills are similarly important sites of copper accumulation at both experimental salinities. In vitro experiments with isolated-perfused gills showed that there is a positive relationship between copper accumulation in this tissue and the metal concentration in the incubation media for both anterior and posterior gills. A similar result was observed at both low and high salinities. Furthermore, in vitro experiments showed that copper accumulation in posterior gills is also positively and strongly dependent on the incubation time with copper. Gill copper accumulation occurred at a lower rate in the first 2h of metal exposure, increasing markedly after this "steady-state" period. This finding was corroborated by a significant

  6. Inhibition of TDP-43 accumulation by bis(thiosemicarbazonato-copper complexes.

    Directory of Open Access Journals (Sweden)

    Sarah J Parker

    Full Text Available Amyotrophic lateral sclerosis (ALS is a progressive, fatal, motor neuron disease with no effective long-term treatment options. Recently, TDP-43 has been identified as a key protein in the pathogenesis of some cases of ALS. Although the role of TDP-43 in motor neuron degeneration is not yet known, TDP-43 has been shown to accumulate in RNA stress granules (SGs in cell models and in spinal cord tissue from ALS patients. The SG association may be an early pathological change to TDP-43 metabolism and as such a potential target for therapeutic intervention. Accumulation of TDP-43 in SGs induced by inhibition of mitochondrial activity can be inhibited by modulation of cellular kinase activity. We have also found that treatment of cells and animal models of neurodegeneration, including an ALS model, with bioavailable bis(thiosemicarbazonatocopper(II complexes (Cu(II(btscs can modulate kinase activity and induce neuroprotective effects. In this study we examined the effect of diacetylbis(-methylthiosemicarbazonatocopper(II (Cu(II(atsm and glyoxalbis(-methylthiosemicarbazonatocopper(II (Cu(II(gtsm on TDP-43-positive SGs induced in SH-SY5Y cells in culture. We found that the Cu(II(btscs blocked formation of TDP-43-and human antigen R (HuR-positive SGs induced by paraquat. The Cu(II(btscs protected neurons from paraquat-mediated cell death. These effects were associated with inhibition of ERK phosphorylation. Co-treatment of cultures with either Cu(II(atsm or an ERK inhibitor, PD98059 both prevented ERK activation and blocked formation of TDP-43-and HuR-positive SGs. Cu(II(atsm treatment or ERK inhibition also prevented abnormal ubiquitin accumulation in paraquat-treated cells suggesting a link between prolonged ERK activation and abnormal ubiquitin metabolism in paraquat stress and inhibition by Cu. Moreover, Cu(II(atsm reduced accumulation of C-terminal (219-414 TDP-43 in transfected SH-SY5Y cells. These results demonstrate that Cu(II(btsc complexes

  7. Enhanced accumulation of copper and lead in amaranth (Amaranthus paniculatus), Indian mustard (Brassica juncea) and sunflower (Helianthus annuus).

    Science.gov (United States)

    Rahman, Motior M; Azirun, Sofian M; Boyce, Amru N

    2013-01-01

    Soil contamination by copper (Cu) and lead (Pb) is a widespread environmental problem. For phytoextraction to be successful and viable in environmental remediation, strategies that can improve plant uptake must be identified. In the present study we investigated the use of nitrogen (N) fertilizer as an efficient way to enhance accumulation of Cu and Pb from contaminated industrial soils into amaranth, Indian mustard and sunflower. Plants were grown in a greenhouse and fertilized with N fertilizer at rates of 0, 190 and 380 mg kg⁻¹ soil. Shoots, roots and total accumulation of Cu and Pb, transfer factor (TF), translocation index were assessed to evaluate the transport and translocation ability of tested plants. Addition of N fertilizer acidified the industrial soil and caused the pH to decrease to 5.5 from an initial pH of 6.9. Industrial soil amended with N fertilizer resulted in the highest accumulation of Pb and Cu (for Pb 10.1-15.5 mg kg⁻¹, for Cu 11.6-16.8 mg kg⁻¹) in the shoots, which was two to four folds higher relative to the concentration in roots in all the three plants used. Sunflower removed significantly higher Pb (50-54%) and Cu (34-38%) followed by amaranth and Indian mustard from industrial soils with the application of N fertilizer. The TF was Sunflower is the best plant species to carry out phytoextraction of Pb and Cu. In contrast, Pb and Cu removal by Indian mustard and amaranth shows great potential as quick and short duration vegetable crops. The results suggest that the application of N fertilizer in contaminated industrial soil is an effective amendment for the phytoextraction of Pb and Cu from contaminated industrial soils.

  8. Mercury, zinc, and copper accumulation in mangrove sediments surrounding a large landfill in southeast Brazil

    International Nuclear Information System (INIS)

    Machado, W.; Moscatelli, M.; Rezende, L.G.; Lacerda, L.D.

    2002-01-01

    Mangrove sediments may prevent movement of metals to adjacent bodies of water. - The accumulation of Hg, Zn, and Cu was evaluated in mangrove sediments located between a large, 20-years-old landfill and waters of Guanabara Bay (southeast Brazil). The contamination history of the area provides substantial evidence that metal accumulation in the study site is influenced by past metal emissions from multiple sources (e.g. contaminated rivers and the landfill surrounding the site). At the southern part of the site, metal levels are up to 890 ng g -1 Hg, 850 μg g -1 Zn, and 58 μg g -1 Cu. Enrichment factors and excess (background-deducted) concentration inventories show a high spatial variability of metal contamination and storage in the site, with differences often by a factor higher than two within a sampling station and higher than five between sampling stations. These contrasts are attributable to a coupling between spatial variability of anthropogenic metal input and metal behavior and retention within the sediments. Results indicate that during the last few decades mangrove sediments retained a substantial part of metal emissions to the site, probably reducing the metal transport to Guanabara Bay waters, and suggest the suitability of mangrove ecosystems as physical and biogeochemical barriers to metal contaminant transport

  9. Accumulation and Toxicity of Copper Oxide Engineered Nanoparticles in a Marine Mussel

    Directory of Open Access Journals (Sweden)

    Shannon K. Hanna

    2014-06-01

    Full Text Available Cu is an essential trace element but can be highly toxic to aquatic organisms at elevated concentrations. Greater use of CuO engineered nanoparticles (ENPs may lead to increased concentrations of CuO ENPs in aquatic environments causing potential ecological injury. We examined the toxicity of CuO ENPs to marine mussels and the influence of mussels on the fate and transport of CuO ENPs. We exposed marine mussels to 1, 2, or 3 mg L−1 CuO ENPs for four weeks, and measured clearance rate, rejection, excretion and accumulation of Cu, and mussel shell growth. Mussel clearance rate was 48% less, and growth was 68% less, in mussels exposed to 3 mg L−1 than in control animals. Previous studies show 100% mortality at 1 mg Cu L−1, suggesting that CuO ENPs are much less toxic than ionic Cu, probably due to the slow dissolution rate of the ENPs. Mussels rejected and excreted CuO ENPs in biodeposits containing as much as 110 mg Cu g−1, suggesting the potential for magnification in sediments. Mussels exposed to 3 mg L−1 CuO ENPs accumulated 79.14 ± 12.46 µg Cu g−1 dry weight, which was 60 times more Cu than in control animals. Our results suggest that mussels have the potential to influence the fate and transport of CuO ENPs and potentially cause magnification of CuO ENPs in mussel bed communities, creating a significant source of Cu to marine benthos.

  10. The HBx oncoprotein of hepatitis B virus deregulates the cell cycle by promoting the intracellular accumulation and re-compartmentalization of the cellular deubiquitinase USP37.

    Directory of Open Access Journals (Sweden)

    Nehul Saxena

    Full Text Available The HBx oncoprotein of hepatitis B Virus has been accredited as one of the protagonists in driving hepatocarcinogenesis. HBx exerts its influence over the cell cycle progression by potentiating the activity of cyclin A/E-CDK2 complex, the Cyclin A partner of which is a well-known target of cellular deubiquitinase USP37. In the present study, we observed the intracellular accumulation of cyclin A and USP37 proteins under the HBx microenvironment. Flow cytometry analysis of the HBx-expressing cells showed deregulation of cell cycle apparently due to the enhanced gene expression and stabilization of USP37 protein and deubiquitination of Cyclin A by USP37. Our co-immunoprecipitation and confocal microscopic studies suggested a direct interaction between USP37 and HBx. This interaction promoted the translocation of USP37 outside the nucleus and prevented its association and ubiquitination by E3 ubiquitin ligases - APC/CDH1 and SCF/β-TrCP. Thus, HBx seems to control the cell cycle progression via the cyclin A-CDK2 complex by regulating the intracellular distribution and stability of deubiquitinase USP37.

  11. Accumulation of Copper in Gill, Liver, Spleen, Kidney and Muscle Tissues of Clarias gariepinus Exposed to the Metal Singly and in Mixture with Chitosan.

    Science.gov (United States)

    Tunçsoy, Mustafa; Duran, Servet; Ay, Özcan; Cicik, Bedii; Erdem, Cahit

    2016-10-01

    Accumulation of copper (Cu), applied singly and in mixture with chitosan (CT), in gill, liver, spleen, kidney and muscle tissues of Clarias gariepinus was studied after exposing the fish to no Cu (control), 5 ppm Cu, 5 ppm Cu + 75 ppm CT mixture over 1, 7 and 15 days. Metal levels in tissues were determined using an ICP-AES spectrophotometer. No mortality was observed during the experiments. Highest accumulation of Cu was observed in liver while lowest accumulation was observed in muscle tissue. Exposure to Cu-CT mixture decreased Cu accumulation in liver at all exposure periods and in kidney on the 15th day compared to Cu alone. Exposure to Cu alone and Cu-CT mixture had no effect on Cu accumulation in spleen or muscle tissue. Copper accumulation increased in gill tissue compared to control when exposed to Cu alone at all exposure periods, and exposure to the Cu-CT mixture significantly increased Cu accumulation in this tissue at all exposure periods compared to Cu alone.

  12. Intracellular d-Serine Accumulation Promotes Genetic Diversity via Modulated Induction of RecA in Enterohemorrhagic Escherichia coli.

    Science.gov (United States)

    Connolly, James P R; Roe, Andrew J

    2016-12-15

    We recently discovered that exposure of enterohemorrhagic Escherichia coli (EHEC) to d-serine resulted in accumulation of this unusual amino acid, induction of the SOS regulon, and downregulation of the type III secretion system that is essential for efficient colonization of the host. Here, we have investigated the physiological relevance of this elevated SOS response, which is of particular interest given the presence of Stx toxin-carrying lysogenic prophages on the EHEC chromosome that are activated during the SOS response. We found that RecA elevation in response to d-serine, while being significant, was heterogeneous and not capable of activating stx expression or stx phage transduction to a nonlysogenic recipient. This "SOS-like response" was, however, capable of increasing the mutation frequency associated with low-level RecA activity, thus promoting genetic diversity. Furthermore, this response was entirely dependent on RecA and enhanced in the presence of a DNA-damaging agent, indicating a functional SOS response, but did not result in observable cleavage of the LexA repressor alone, indicating a controlled mechanism of induction. This work demonstrates that environmental factors not usually associated with DNA damage are capable of promoting an SOS-like response. We propose that this modulated induction of RecA allows EHEC to adapt to environmental insults such as d-serine while avoiding unwanted phage-induced lysis. The SOS response is a global stress network that is triggered by the presence of DNA damage due to breakage or stalled replication forks. Activation of the SOS response can trigger the replication of lytic bacteriophages and promote genetic diversification through error-prone polymerases. We have demonstrated that the host-associated metabolite d-serine contributes to Escherichia coli niche specification and accumulates inside cells that cannot catabolize it. This results in a modulated activation of the SOS antirepressor RecA that is

  13. Differential Tissue Accumulation of Copper, Iron, and Zinc in Bycatch Fish from the Mexican Pacific.

    Science.gov (United States)

    Spanopoulos-Zarco, P; Ruelas-Inzunza, J; Aramburo-Moran, I S; Bojórquez-Leyva, H; Páez-Osuna, F

    2017-03-01

    In order to ascertain if Cu, Fe, and Zn are differentially accumulated in fish tissues, metal concentrations were measured in the muscle and liver of bycatch fish from the states of Sinaloa (189 specimens, 7 species) and Guerrero (152 individuals, 8 species) in the Mexican Pacific Coast during March and November 2011. Additionally, metal levels were compared with the maximum allowable limits set by international legislation and contrasted with similar ichthyofauna from other regions. Liver had more elevated concentrations of Cu (Sinaloa 28.3, Guerrero 16.3 μg g -1 ), Fe (Sinaloa 1098, Guerrero 636 μg g -1 ), and Zn (Sinaloa 226, Guerrero 186 μg g -1 ) than the muscle in fish from both studied areas. The relative abundances of analyzed metals in both tissues was Fe > Zn > Cu. As far as limits set by international legislation (Australia, India, New Zealand, Zambia), measured concentrations of Cu in the edible portion of fish were not found to be above the set values. In the case of Zn, the maximum allowable limits set by international legislation were exceeded by the Peruvian mojarra Diapterus peruvianus from Guerrero state (Mexican Pacific). No limits exist for Fe in the edible portion of fishery products in the national and international legislations.

  14. Intracellular translocation and differential accumulation of cell-penetrating peptides in bovine spermatozoa: evaluation of efficient delivery vectors that do not compromise human sperm motility

    Science.gov (United States)

    Jones, Sarah; Lukanowska, Monika; Suhorutsenko, Julia; Oxenham, Senga; Barratt, Christopher; Publicover, Steven; Copolovici, Dana Maria; Langel, Ülo; Howl, John

    2013-01-01

    STUDY QUESTION Do cell penetrating peptides (CPPs) translocate into spermatozoa and, if so, could they be utilized to deliver a much larger protein cargo? SUMMARY ANSWER Chemically diverse polycationic CPPs rapidly and efficiently translocate into spermatozoa. They exhibit differential accumulation within intracellular compartments without detrimental influences upon cellular viability or motility but they are relatively ineffective in transporting larger proteins. WHAT IS ALREADY KNOWN Endocytosis, the prevalent route of protein internalization into eukaryotic cells, is severely compromised in mature spermatozoa. Thus, the translocation of many bioactive agents into sperm is relatively inefficient. However, the delivery of bioactive moieties into mature spermatozoa could be significantly improved by the identification and utility of an efficient and inert vectorial delivery technology. STUDY DESIGN CPP translocation efficacies, their subsequent differential intracellular distribution and the influence of peptides upon viability were determined in bovine spermatozoa. Temporal analyses of sperm motility in the presence of exogenously CPPs utilized normozoospermic human donor samples. MATERIALS AND METHODS CPPs were prepared by manual, automated and microwave-enhanced solid phase synthesis. Confocal fluorescence microscopy determined the intracellular distribution of rhodamine-conjugated CPPs in spermatozoa. Quantitative uptake and kinetic analyses compared the translocation efficacies of chemically diverse CPPs and conjugates of biotinylated CPPs and avidin. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) conversion assays were employed to analyse the influence of CPPs upon sperm cell viability and sperm class assays determined the impact of CPPs on motility in capacitated and non-capacitated human samples. MAIN RESULTS Chemically heterogeneous CPPs readily translocated into sperm to accumulate within

  15. Toxicity and accumulation of Copper oxide (CuO) nanoparticles in different life stages of Artemia salina.

    Science.gov (United States)

    Madhav, M R; David, S Einstein Mariya; Kumar, R S Suresh; Swathy, J S; Bhuvaneshwari, M; Mukherjee, Amitava; Chandrasekaran, N

    2017-06-01

    Metal nanoparticles production rate and its applications have raised concerns about their release and toxicity to the aquatic and terrestrial organisms. The primary size of Copper Oxide nanoparticles (CuO NP's) was found to be 114±36nm using Scanning Electron Microscopy (SEM) and a significant increase in the hydrodynamic diameter of CuO NP was seen within 1h of interaction. The median lethal concentration (LC 50 ) values obtained from the acute toxicity studies on different life stages of Artemia salina was found to be 61.4, 35, 12.2 and 175.2mg/L for 1d, 2d, 7d old and adult, respectively. The toxicity associated changes in biochemical markers such as Catalase, Reduced glutathione and Glutathione-S-Transferase were evident. The accumulation of Cu nanoparticles into the gut of Artemia salina was the major reason for toxicity. This study demonstrate the toxicity of CuO NPs to Artemia salina, and the obtained results necessitate the detailed investigation on the possible eco-toxicological implication of these nanomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Enhanced accumulation of copper and lead in amaranth (Amaranthus paniculatus, Indian mustard (Brassica juncea and sunflower (Helianthus annuus.

    Directory of Open Access Journals (Sweden)

    Motior M Rahman

    Full Text Available BACKGROUND: Soil contamination by copper (Cu and lead (Pb is a widespread environmental problem. For phytoextraction to be successful and viable in environmental remediation, strategies that can improve plant uptake must be identified. In the present study we investigated the use of nitrogen (N fertilizer as an efficient way to enhance accumulation of Cu and Pb from contaminated industrial soils into amaranth, Indian mustard and sunflower. METHODS/PRINCIPAL FINDINGS: Plants were grown in a greenhouse and fertilized with N fertilizer at rates of 0, 190 and 380 mg kg⁻¹ soil. Shoots, roots and total accumulation of Cu and Pb, transfer factor (TF, translocation index were assessed to evaluate the transport and translocation ability of tested plants. Addition of N fertilizer acidified the industrial soil and caused the pH to decrease to 5.5 from an initial pH of 6.9. Industrial soil amended with N fertilizer resulted in the highest accumulation of Pb and Cu (for Pb 10.1-15.5 mg kg⁻¹, for Cu 11.6-16.8 mg kg⁻¹ in the shoots, which was two to four folds higher relative to the concentration in roots in all the three plants used. Sunflower removed significantly higher Pb (50-54% and Cu (34-38% followed by amaranth and Indian mustard from industrial soils with the application of N fertilizer. The TF was <1 while the shoot and root concentration (SC/RC ratios of Pb and Cu were between 1.3-4.3 and 1.8-3.8, respectively, regardless of plant species. CONCLUSIONS: Sunflower is the best plant species to carry out phytoextraction of Pb and Cu. In contrast, Pb and Cu removal by Indian mustard and amaranth shows great potential as quick and short duration vegetable crops. The results suggest that the application of N fertilizer in contaminated industrial soil is an effective amendment for the phytoextraction of Pb and Cu from contaminated industrial soils.

  17. Forms and accumulation of copper and zinc in a sandy typic hapludalf soil after long-term application of pig slurry and deep litter

    OpenAIRE

    Tadeu Luis Tiecher; Carlos Alberto Ceretta; Jucinei José Comin; Eduardo Girotto; Alcione Miotto; Marcel Pires de Moraes; Lucas Benedet; Paulo Ademar Avelar Ferreira; Cledimar Rogério Lorenzi; Rafael da Rosa Couto; Gustavo Brunetto

    2013-01-01

    Successive applications of pig slurry and pig deep litter may lead to an accumulation of copper (Cu) and zinc (Zn) fractions in the soil profile. The objective of this study was to evaluate the Cu and Zn forms and accumulation in a Sandy Typic Hapludalf soil after long-term application of pig slurry and deep litter. In March 2010, eight years after initiating an experiment in Braço do Norte, Santa Catarina (SC), Brazil, on a Sandy Typic Hapludalf soil, soil samples were collected from the 0-2...

  18. CPB1 of Aedes aegypti Interacts with DENV2 E Protein and Regulates Intracellular Viral Accumulation and Release from Midgut Cells

    Directory of Open Access Journals (Sweden)

    Hong-Wai Tham

    2014-12-01

    Full Text Available Aedes aegypti is a principal vector responsible for the transmission of dengue viruses (DENV. To date, vector control remains the key option for dengue disease management. To develop new vector control strategies, a more comprehensive understanding of the biological interactions between DENV and Ae. aegypti is required. In this study, a cDNA library derived from the midgut of female adult Ae. aegypti was used in yeast two-hybrid (Y2H screenings against DENV2 envelope (E protein. Among the many interacting proteins identified, carboxypeptidase B1 (CPB1 was selected, and its biological interaction with E protein in Ae. aegypti primary midgut cells was further validated. Our double immunofluorescent assay showed that CPB1-E interaction occurred in the endoplasmic reticulum (ER of the Ae. aegypti primary midgut cells. Overexpression of CPB1 in mosquito cells resulted in intracellular DENV2 genomic RNA or virus particle accumulation, with a lower amount of virus release. Therefore, we postulated that in Ae. aegypti midgut cells, CPB1 binds to the E protein deposited on the ER intraluminal membranes and inhibits DENV2 RNA encapsulation, thus inhibiting budding from the ER, and may interfere with immature virus transportation to the trans-Golgi network.

  19. Comparison of intracellular accumulation and cytotoxicity of free mTHPC and mTHPC-loaded PLGA nanoparticles in human colon carcinoma cells

    International Nuclear Information System (INIS)

    Loew, Karin; Wagner, Sylvia; Briesen, Hagen von; Knobloch, Thomas; Wiehe, Arno; Engel, Andrea; Langer, Klaus

    2011-01-01

    The second generation photosensitizer mTHPC was approved by the European Medicines Agency (EMA) for the palliative treatment of advanced head and neck cancer in October 2001. It is known that mTHPC possesses a significant phototoxicity against a variety of human cancer cells in vitro but also exhibits dark toxicity and can cause adverse effects (especially skin photosensitization). Due to its poor water solubility, the administration of hydrophobic photosensitizer still presents several difficulties. To overcome the administration problems, the use of nanoparticles as drug carrier systems is much investigated. Nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) have been extensively studied as delivery systems into tumours due to their biocompatibility and biodegradability. The goal of this study was the comparison of free mTHPC and mTHPC-loaded PLGA nanoparticles concerning cytotoxicity and intracellular accumulation in human colon carcinoma cells (HT29). The nanoparticles delivered the photosensitizer to the colon carcinoma cells and enabled drug release without losing its activity. The cytotoxicity assays showed a time- and concentration-dependent decrease in cell proliferation and viability after illumination. However, first and foremost mTHPC lost its dark toxic effects using the PLGA nanoparticles as a drug carrier system. Therefore, PLGA nanoparticles are a promising drug carrier system for the hydrophobic photosensitizer mTHPC.

  20. Use of the aquatic lichen Dermatocarpon luridum as bioindicator of copper pollution: Accumulation and cellular distribution tests

    Energy Technology Data Exchange (ETDEWEB)

    Monnet, Fabien [Laboratoire des sciences de l' eau et de l' environnement, Faculte des sciences, Universite de Limoges, 123 Avenue Albert Thomas, F-87060 Limoges (France)]. E-mail: fabien.monnet@univ-avignon.fr; Bordas, Francois [Laboratoire des sciences de l' eau et de l' environnement, Faculte des sciences, Universite de Limoges, 123 Avenue Albert Thomas, F-87060 Limoges (France); Deluchat, Veronique [Laboratoire des sciences de l' eau et de l' environnement, Faculte des sciences, Universite de Limoges, 123 Avenue Albert Thomas, F-87060 Limoges (France); Chatenet, Philippe [Laboratoire des sciences de l' eau et de l' environnement, Faculte des sciences, Universite de Limoges, 123 Avenue Albert Thomas, F-87060 Limoges (France); Botineau, Michel [Laboratoire des sciences de l' eau et de l' environnement, Faculte des sciences, Universite de Limoges, 123 Avenue Albert Thomas, F-87060 Limoges (France); Baudu, Michel [Laboratoire des sciences de l' eau et de l' environnement, Faculte des sciences, Universite de Limoges, 123 Avenue Albert Thomas, F-87060 Limoges (France)

    2005-12-15

    Laboratory experiments were conducted to investigate the potential use of the aquatic lichen Dermatocarpon luridum as bioindicator of copper pollution. Lichen thalli were exposed to 0.00, 0.25, 0.50, 0.75 and 1.00 mM copper in synthetic freshwater to solve the problems of metal bioavailability. The mineral composition of this media was prepared so that it corresponded to the ion composition of natural waters in D. luridum ecosystems. Sequential elution procedures using NiCl{sub 2} or Na{sub 2}-EDTA (20 mM) were used to determine the distribution of metals at different cellular sites. The copper concentration extracted from thalli was correlated with pollution intensity, the greater correlation being with the Na{sub 2}-EDTA extractant. The malondialdehyde concentration in thalli can be used as indicator of copper pollution; however, similar membrane degradation was observed for 0.25 and 0.50 mM copper and for 0.75 and 1.00 mM copper. - The copper concentration in thalli of aquatic lichens is correlated with pollution intensity.

  1. Intracellular cholesterol level regulates sensitivity of glioblastoma cells against temozolomide-induced cell death by modulation of caspase-8 activation via death receptor 5-accumulation and activation in the plasma membrane lipid raft.

    Science.gov (United States)

    Yamamoto, Yutaro; Tomiyama, Arata; Sasaki, Nobuyoshi; Yamaguchi, Hideki; Shirakihara, Takuya; Nakashima, Katsuhiko; Kumagai, Kosuke; Takeuchi, Satoru; Toyooka, Terushige; Otani, Naoki; Wada, Kojiro; Narita, Yoshitaka; Ichimura, Koichi; Sakai, Ryuichi; Namba, Hiroki; Mori, Kentaro

    2018-01-01

    Development of resistance against temozolomide (TMZ) in glioblastoma (GBM) after continuous treatment with TMZ is one of the critical problems in clinical GBM therapy. Intracellular cholesterol regulates cancer cell biology, but whether intracellular cholesterol is involved in TMZ resistance of GBM cells remains unclear. The involvement of intracellular cholesterol in acquired resistance against TMZ in GBM cells was investigated. Intracellular cholesterol levels were measured in human U251 MG cells with acquired TMZ resistance (U251-R cells) and TMZ-sensitive control U251 MG cells (U251-Con cells), and found that the intracellular cholesterol level was significantly lower in U251-R cells than in U251-Con cells. In addition, treatment by intracellular cholesterol remover, methyl-beta cyclodextrin (MβCD), or intracellular cholesterol inducer, soluble cholesterol (Chol), regulated TMZ-induced U251-Con cell death in line with changes in intracellular cholesterol level. Involvement of death receptor 5 (DR5), a death receptor localized in the plasma membrane, was evaluated. TMZ without or with MβCD and/or Chol caused accumulation of DR5 into the plasma membrane lipid raft and formed a complex with caspase-8, an extrinsic caspase cascade inducer, reflected in the induction of cell death. In addition, treatment with caspase-8 inhibitor or knockdown of DR5 dramatically suppressed U251-Con cell death induced by combination treatment with TMZ, MβCD, and Chol. Combined treatment of Chol with TMZ reversed the TMZ resistance of U251-R cells and another GBM cell model with acquired TMZ resistance, whereas clinical antihypercholesterolemia agents at physiological concentrations suppressed TMZ-induced cell death of U251-Con cells. These findings suggest that intracellular cholesterol level affects TMZ treatment of GBM mediated via a DR5-caspase-8 mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Evidence for early intracellular accumulation of volatile compounds during spadix development in Arum italicum L. and preliminary data on some tropical Aroids

    Science.gov (United States)

    Leguet, Aurélia; Gibernau, Marc; Shintu, Laetitia; Caldarelli, Stefano; Moja, Sandrine; Baudino, Sylvie; Caissard, Jean-Claude

    2014-08-01

    Staining and histochemistry of volatile organic compounds (VOCs) were performed at different inflorescence developmental stages on nine aroid species; one temperate, Arum italicum and eight tropical from the genera Caladium, Dieffenbachia and Philodendron. Moreover, a qualitative and quantitative analysis of VOCs constituting the scent of A. italicum, depending on the stage of development of inflorescences was also conducted. In all nine species, vesicles were observed in the conical cells of either the appendix or the stamens (thecae) and the staminodes. VOCs were localised in intracellular vesicles from the early stages of inflorescence development until their release during receptivity of gynoecium. This localisation was observed by the increase of both number and diameter of the vesicles during 1 week before receptivity. Afterwards, vesicles were fewer and smaller but rarely absent. In A. italicum, staining and gas chromatography analyses confirmed that the vesicles contained terpenes. The quantitatively most important ones were the sesquiterpenes, but monoterpenes were not negligible. Indeed, the quantities of terpenes matched the vesicles' size evolution during 1 week. Furthermore, VOCs from different biosynthetic pathways (sesquiterpenes and alkanes) were at their maximum quantity 2 days before gynoecium receptivity (sesquiterpenes and alkanes) or during receptivity (isobutylamine, monoterpenes, skatole and p-cresol). VOCs seemed to be emitted during gynoecium receptivity and/or during thermogenesis, and FADs are accumulated after thermogenesis in the spadix. These complex dynamics of the different VOCs could indicate specialisation of some VOCs and cell machinery to attract pollinators on the one hand and to repulse/protect against phytophagous organisms and pathogens after pollination on the other hand.

  3. Effects of coal spoil amendment on heavy metal accumulation and physiological aspects of ryegrass (Lolium perenne L.) growing in copper mine tailings.

    Science.gov (United States)

    Chu, Zhaoxia; Wang, Xingming; Wang, Yunmin; Liu, Guijian; Dong, Zhongbing; Lu, Xianwen; Chen, Guangzhou; Zha, Fugeng

    2017-12-21

    Copper mine tailings pose many threats to the surrounding environment and human health, and thus, their remediation is fundamental. Coal spoil is the waste by-product of coal mining and characterized by low levels of metals, high content of organic matter, and many essential microelements. This study was designed to evaluate the role of coal spoil on heavy uptake and physiological responses of Lolium perenne L. grown in copper mine tailings amended with coal spoil at rates of 0, 0.5, 1, 5, 10, and 20%. The results showed that applying coal spoil to copper mine tailings decreased the diethylenetriaminepentaacetic acid (DTPA)-extractable Cd, Cu, Pb, and Zn contents in tailings and reduced those metal contents in both roots and shoots of the plant. However, application of coal spoil increased the DTPA-extractable Cr concentration in tailings and also increased Cr uptake and accumulation by Lolium perenne L. The statistical analysis of physiological parameters indicated that chlorophyll and carotenoid increased at the lower amendments of coal spoil followed by a decrease compared to their respective controls. Protein content was enhanced at all the coal spoil amendments. When treated with coal spoil, the activities of superoxide dismutases (SOD), peroxidase (POD), and catalase (CAT) responded differently. CAT activity was inhibited, but POD activity was increased with increasing amendment ratio of coal spoil. SOD activity increased up to 1% coal spoil followed by a decrease. Overall, the addition of coal spoil decreased the oxidative stress in Lolium perenne L., reflected by the reduction in malondialdehyde (MDA) contents in the plant. It is concluded that coal spoil has the potential to stabilize most metals studied in copper mine tailings and ameliorate the harmful effects in Lolium perenne L. through changing the physiological attributes of the plant grown in copper mine tailings.

  4. Mutation of Glycosylation Sites in BST-2 Leads to Its Accumulation at Intracellular CD63-Positive Vesicles without Affecting Its Antiviral Activity against Multivesicular Body-Targeted HIV-1 and Hepatitis B Virus.

    Science.gov (United States)

    Han, Zhu; Lv, Mingyu; Shi, Ying; Yu, Jinghua; Niu, Junqi; Yu, Xiao-Fang; Zhang, Wenyan

    2016-02-29

    BST-2/tetherin blocks the release of various enveloped viruses including HIV-1 with a "physical tethering" model. The detailed contribution of N-linked glycosylation to this model is controversial. Here, we confirmed that mutation of glycosylation sites exerted an effect of post-translational mis-trafficking, leading to an accumulation of BST-2 at intracellular CD63-positive vesicles. BST-2 with this phenotype potently inhibited the release of multivesicular body-targeted HIV-1 and hepatitis B virus, without affecting the co-localization of BST-2 with EEA1 and LAMP1. These results suggest that N-linked glycosylation of human BST-2 is dispensable for intracellular virion retention and imply that this recently discovered intracellular tethering function may be evolutionarily distinguished from the canonical antiviral function of BST-2 by tethering nascent virions at the cell surface.

  5. Salinity-dependent copper accumulation in the guppy Poecilia vivipara is associated with CTR1 and ATP7B transcriptional regulation.

    Science.gov (United States)

    da Silva, Evelise Sampaio; Abril, Sandra Isabel Moreno; Zanette, Juliano; Bianchini, Adalto

    2014-07-01

    Copper (Cu) accumulation and regulation of key-genes involved in Cu homeostasis were evaluated in freshwater- and saltwater-acclimated guppies Poecilia vivipara. Fish were exposed (96h) to environmentally relevant concentrations of dissolved Cu (0, 5.0, 9.0 and 20.0μg/L). In freshwater guppies, gill and liver Cu accumulation was dependent on Cu concentration in the exposure medium. In saltwater guppies, this dependence was observed only in the gut. These findings indicate that Cu accumulation was salinity- and tissue-dependent. Key genes involved in Cu metabolism were sequenced for the first time in P. vivipara. Transcripts coding for the high-affinity copper transporter (CTR1) and copper-transporting ATPase (ATP7B) were identified using polymerase chain reaction (PCR) and gene sequencing. The full-length CTR1 open reading frame (1560bp) and a partial ATP7B (690bp) were discovered. Predicted amino acid sequences shared high identities with the CTR1 of Fundulus heteroclitus (81%) and the ATP7B of Sparus aurata (87%). Basal transcriptional levels addressed by RT-qPCR in control fish indicate that CTR1 and ATP7B was highly transcribed in liver of freshwater guppies while CTR1 was highly transcribed in gut of saltwater guppies. This could explain the higher Cu accumulation observed in liver of freshwater guppies and in gut of saltwater guppies, because CTR1 is involved in Cu uptake. Reduced gill mRNA expression of CTR1 was observed in freshwater guppies exposed to 20.0μg/L Cu and in saltwater guppies exposed to 5.0μg/L Cu. In turn, reduced mRNA expression of gut ATP7B was observed in freshwater and salt water guppies exposed to 9.0 and 20.0μg/L Cu. Liver CTR1 and ATP7B transcription were not affected by Cu exposure. These findings suggest that gill CTR1 and gut ATP7B are down-regulated to limit Cu absorption after exposure to dissolved Cu, while liver CTR1 and ATP7B levels are maintained to allow Cu storage and detoxification. In conclusion, findings reported here

  6. Clonal differences in survival capacity, copper and zinc accumulation, and correlation with leaf polyamine levels in poplar: A large-scale field trial on heavily polluted soil

    International Nuclear Information System (INIS)

    Castiglione, S.; Todeschini, V.; Franchin, C.; Torrigiani, P.; Gastaldi, D.; Cicatelli, A.; Rinaudo, C.; Berta, G.; Biondi, S.; Lingua, G.

    2009-01-01

    Three ex situ collections of poplar clones from natural populations of Populus alba and P. nigra growing in northern Italy were assessed for their genetic dissimilarity (GD) by means of amplified fragment length polymorphism (AFLP). The high GD evidenced within populations was exploited for screening 168 clones in a field trial on heavy metal-polluted soil. After one growth season, clonal differences in plant survival and growth were observed. On the basis of performance, six clones were singled out, and used to evaluate copper and zinc accumulation in different organs. Clonal differences in metal concentrations were most evident for leaves and stems; one clone of P. alba (AL35) had a distinctly higher concentration of both metals in the roots. Leaf polyamine (putrescine, spermidine, spermine) profiles correlated with tissue metal concentrations, depending on the clone, plant organ and metal. In particular, the high metal-accumulating clone AL35 exhibited a dramatically higher concentration of free and conjugated putrescine. Overall, the results indicate that, given the high GD of Populus even within populations, it is possible to identify genotypes best suited for soil clean-up, and useful also for investigating physiological markers associated with high metal accumulation/tolerance - High survival rate and heavy metal accumulation are associated with high polyamine concentration in an elite poplar clone.

  7. Clonal differences in survival capacity, copper and zinc accumulation, and correlation with leaf polyamine levels in poplar: A large-scale field trial on heavily polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Castiglione, S. [Dipartimento di Biologia, Universita di Milano, Via Celoria 25, I-20100 Milano (Italy); Todeschini, V. [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy); Franchin, C. [Dipartimento di Biologia e.s., Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Torrigiani, P. [Dipartimento di Colture Arboree, Universita di Bologna, Via Fanin 46, I-40127 Bologna (Italy); Gastaldi, D. [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy); Cicatelli, A. [Dipartimento di Chimica, Universita di Salerno, Stecca 7, Via Ponte don Melillo, I-84084 Fisciano (Saudi Arabia) (Italy); Rinaudo, C.; Berta, G. [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy); Biondi, S. [Dipartimento di Biologia e.s., Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Lingua, G., E-mail: guido.lingua@mfn.unipmn.i [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy)

    2009-07-15

    Three ex situ collections of poplar clones from natural populations of Populus alba and P. nigra growing in northern Italy were assessed for their genetic dissimilarity (GD) by means of amplified fragment length polymorphism (AFLP). The high GD evidenced within populations was exploited for screening 168 clones in a field trial on heavy metal-polluted soil. After one growth season, clonal differences in plant survival and growth were observed. On the basis of performance, six clones were singled out, and used to evaluate copper and zinc accumulation in different organs. Clonal differences in metal concentrations were most evident for leaves and stems; one clone of P. alba (AL35) had a distinctly higher concentration of both metals in the roots. Leaf polyamine (putrescine, spermidine, spermine) profiles correlated with tissue metal concentrations, depending on the clone, plant organ and metal. In particular, the high metal-accumulating clone AL35 exhibited a dramatically higher concentration of free and conjugated putrescine. Overall, the results indicate that, given the high GD of Populus even within populations, it is possible to identify genotypes best suited for soil clean-up, and useful also for investigating physiological markers associated with high metal accumulation/tolerance - High survival rate and heavy metal accumulation are associated with high polyamine concentration in an elite poplar clone.

  8. A Study on the Processes of Distribution, Accumulation and Transfer of Copper (Cu in the Organisms of Fishes

    Directory of Open Access Journals (Sweden)

    Iliana G. Velcheva

    2009-07-01

    Full Text Available By applying mathematical approaches we studied the distribution of copper in organs and tissues of Alburnus alburnus and Perca fluviatilis from "Topolnitsa” Dam Lake. A deposit of the metal in the kidneys and liver was recorded. We found out that the surveyed species are macroconcentrators of cadmium and zinc and there is a process biomagnification of heavy metals in the trophic levels.

  9. Forms and accumulation of copper and zinc in a sandy typic hapludalf soil after long-term application of pig slurry and deep litter

    Directory of Open Access Journals (Sweden)

    Tadeu Luis Tiecher

    2013-06-01

    Full Text Available Successive applications of pig slurry and pig deep litter may lead to an accumulation of copper (Cu and zinc (Zn fractions in the soil profile. The objective of this study was to evaluate the Cu and Zn forms and accumulation in a Sandy Typic Hapludalf soil after long-term application of pig slurry and deep litter. In March 2010, eight years after initiating an experiment in Braço do Norte, Santa Catarina (SC, Brazil, on a Sandy Typic Hapludalf soil, soil samples were collected from the 0-2.5, 2.5-5.0, 5-10 and 10-15 cm layers in treatments consisting of no manure application (control and with applications of pig slurry and deep litter at two levels: the single and double rate of N requirement for maize and black oat succession. The soil was dried, ground in an agate mortar and analyzed for Cu and Zn contents by 0.01 mol L-1 EDTA and chemically fractionated to determine Cu and Zn. The applications of Pig deep litter and slurry at doses equivalent to 90 kg ha-1 N increased the contents of available Cu and Zn in the surface soil layer, if the double of this dose was applied in pig deep litter or double this dose in pig slurry, Cu and Zn migrated to a depth of 15 cm. Copper is accumulated mainly in the organic and residual fractions, and zinc preferentially in the fraction linked to clay minerals, especially in the surface soil layers.

  10. A heavy metal P-type ATPase OsHMA4 prevents copper accumulation in rice grain

    Science.gov (United States)

    As one of the most important staple crops, rice not only provides more than one fifth of daily calories for half of the world’s human population but is also a major source of mineral nutrients. However, little is known about the genetic basis of mineral nutrient accumulation in rice grain such as co...

  11. Copper deprivation modulates CTR1 and CUP1 expression and enhances cisplatin cytotoxicity in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kommuguri, Upendra Nadh; Bodiga, Sreedhar; Sankuru, Suneetha; Bodiga, Vijaya Lakshmi

    2012-01-01

    Saccharomyces cerevisiae has been established as a model system for cancer studies, due to the widely conserved family of genes involved in cell cycle progression, proliferation and apoptosis. In the current study, we sought to determine whether copper deprivation modulates sensitivity of yeast to cisplatin. Yeast cultures grown in low copper medium and exposed to bathocuproiene disulfate (BCS) resulted in significant reduction of intracellular copper. We report here that low copper medium rendered BY4741 hypersensitive to cisplatin (CDDP). Yeast grown in low copper medium exhibited ∼2.0 fold enhanced cytotoxicity in survival and colony-forming ability, compared to copper adequate control cells grown in YPD. The effect of copper restriction on CDDP sensitivity appeared to be associated with the up regulation of CTR1, facilitating enhanced uptake and accumulation of CDDP. Also, CDDP further lowered copper deprivation-induced changes in CUP1 metallothionein levels, SOD activity and GSH levels. These changes were associated with increased protein oxidation and lipid peroxidation induced by CDDP. These results thus suggest that cisplatin cytotoxicity is potentiated under low copper conditions due to enhanced uptake and accumulation of cisplatin and also in part due to lowered antioxidant defense and increased oxidative stress imposed by copper deprivation. Copyright © 2011 Elsevier GmbH. All rights reserved.

  12. Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation

    International Nuclear Information System (INIS)

    Cao, Fangbin; Wang, Runfeng; Cheng, Wangda; Zeng, Fanrong; Ahmed, Imrul Mosaddek; Hu, Xinna; Zhang, Guoping; Wu, Feibo

    2014-01-01

    The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.4% samples, respectively, were above the maximum permissible concentration (MPC); none of samples had Cr/Cu exceeding MPC. Stepwise multiple linear regression analysis estimated soil HM critical levels for safe rice production. Low grain HM accumulation cultivars such as Xiushui817, Jiayou08-1 and Chunyou689 were recommended as suitable cultivars for planting in slight/medium HM contaminated soils. The alleviating regulator (AR) of (NH 4 ) 2 SO 4 as N fertilizer coupled with foliar spray of a mixture containing glutathione (GSH), Si, Zn and Se significantly decreased grain Cd, Cr, Cu and Pb concentrations grown in HM contaminated fields with no effect on yield, indicating a promising measurement for further reducing grain HM content to guarantee safe food production. - Highlights: • Field trials evaluated situation of grain HM in main rice growing areas of Zhejiang. • Forecasting index system to predict rice grain HM concentration was achieved. • Hybrid rice holds higher grain Cd concentration than conventional cultivars. • Low grain HM accumulation rice cultivars were successfully identified. • Developed alleviating regulator which effectively reduced grain toxic HM

  13. Intracellular accumulation of a 46 kDa species of mouse prion protein as a result of loss of glycosylation in cultured mammalian cells

    NARCIS (Netherlands)

    Biswas, S.; Langeveld, J.P.M.; Tipper, D.; Lu, S.

    2006-01-01

    Prion diseases are fatal neurodegenerative disorders characterized by the accumulation of an abnormal isoform (PrPSc) of the normal cellular prion protein (PrPC) in the brain. Reportedly, abnormal N-linked glycosylation patterns in PrPC are associated with disease susceptibility; thus, we compared

  14. Canine Copper-Associated Hepatitis

    NARCIS (Netherlands)

    Dirksen, Karen|info:eu-repo/dai/nl/412424428; Fieten, Hille|info:eu-repo/dai/nl/314112596

    2017-01-01

    Copper-associated hepatitis is recognized with increasing frequency in dogs. The disease is characterized by centrolobular hepatic copper accumulation, leading to hepatitis and eventually cirrhosis. The only way to establish the diagnosis is by histologic assessment of copper distribution and copper

  15. Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation.

    Science.gov (United States)

    Cao, Fangbin; Wang, Runfeng; Cheng, Wangda; Zeng, Fanrong; Ahmed, Imrul Mosaddek; Hu, Xinna; Zhang, Guoping; Wu, Feibo

    2014-10-15

    The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.4% samples, respectively, were above the maximum permissible concentration (MPC); none of samples had Cr/Cu exceeding MPC. Stepwise multiple linear regression analysis estimated soil HM critical levels for safe rice production. Low grain HM accumulation cultivars such as Xiushui817, Jiayou08-1 and Chunyou689 were recommended as suitable cultivars for planting in slight/medium HM contaminated soils. The alleviating regulator (AR) of (NH₄)₂SO₄ as N fertilizer coupled with foliar spray of a mixture containing glutathione (GSH), Si, Zn and Se significantly decreased grain Cd, Cr, Cu and Pb concentrations grown in HM contaminated fields with no effect on yield, indicating a promising measurement for further reducing grain HM content to guarantee safe food production. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Expression of the alaE gene is positively regulated by the global regulator Lrp in response to intracellular accumulation of l-alanine in Escherichia coli.

    Science.gov (United States)

    Ihara, Kohei; Sato, Kazuki; Hori, Hatsuhiro; Makino, Yumiko; Shigenobu, Shuji; Ando, Tasuke; Isogai, Emiko; Yoneyama, Hiroshi

    2017-04-01

    The alaE gene in Escherichia coli encodes an l-alanine exporter that catalyzes the active export of l-alanine using proton electrochemical potential. In our previous study, alaE expression was shown to increase in the presence of l-alanyl-l-alanine (Ala-Ala). In this study, the global regulator leucine-responsive regulatory protein (Lrp) was identified as an activator of the alaE gene. A promoter less β-galactosidase gene was fused to an alaE upstream region (240 nucleotides). Cells that were lacZ-deficient and harbored this reporter plasmid showed significant induction of β-galactosidase activity (approximately 17-fold) in the presence of 6 mM l-alanine, l-leucine, and Ala-Ala. However, a reporter plasmid possessing a smaller alaE upstream region (180 nucleotides) yielded transformants with strikingly low enzyme activity under the same conditions. In contrast, lrp-deficient cells showed almost no β-galactosidase induction, indicating that Lrp positively regulates alaE expression. We next performed an electrophoretic mobility shift assay (EMSA) and a DNase I footprinting assay using purified hexahistidine-tagged Lrp (Lrp-His). Consequently, we found that Lrp-His binds to the alaE upstream region spanning nucleotide -161 to -83 with a physiologically relevant affinity (apparent K D , 288.7 ± 83.8 nM). Furthermore, the binding affinity of Lrp-His toward its cis-element was increased by l-alanine and l-leucine, but not by Ala-Ala and d-alanine. Based on these results, we concluded that the gene expression of the alaE is regulated by Lrp in response to intracellular levels of l-alanine, which eventually leads to intracellular homeostasis of l-alanine concentrations. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Effects of chronic exposure to waterborne copper and nickel in binary mixture on tissue-specific metal accumulation and reproduction in fathead minnow (Pimephales promelas).

    Science.gov (United States)

    Driessnack, Melissa K; Jamwal, Ankur; Niyogi, Som

    2017-10-01

    The current study evaluated the interactive effects of chronic waterborne copper (Cu) and nickel (Ni) exposure on tissue-specific metal accumulation and reproductive performance in fathead minnow (Pimephales promelas). Fish trios (1 male: 2 female; n = 5-6) were exposed for 21 days to: (i) control (no added Cu or Ni), (ii) waterborne Cu (45 μg/L), (iii) waterborne Ni (270 μg/L), and (iv) binary mixture of waterborne Cu and Ni (45 and 270 μg/L, respectively). Fish fecundity (cumulative egg production) was found to be the most sensitive reproductive endpoint, and the interaction of Cu and Ni elicited an additive effect on egg production. Tissue-specific accumulation of both metals was not influenced by the interaction of Cu and Ni, except an increased Cu and Ni burden in the carcass and ovary, respectively, were recorded. The expressions of hepatic estrogen receptor genes (ER-α and ER-β) and the circulating estradiol level in females were also not affected by the metal-mixture treatment. However, co-exposure to waterborne Cu and Ni resulted in a significant downregulation of the hepatic vitellogenin gene in females, which was associated with the maximum upregulation of the hepatic metallothionein gene. In addition, a significant alteration of ovarian histopathology (decreased abundance of post-vitellogenic follicles, and increased follicular atresia) was also observed only in females exposed to Cu and Ni in mixture. Collectively, these observations suggest that chronic waterborne exposure to Cu and Ni in binary mixture may impair fish reproductive capacity by inducing histopathological damage in ovarian tissue, and disrupting of energy homeostasis in fish. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Identification and Characterization of Oleaginous Yeast Isolated from Kefir and Its Ability to Accumulate Intracellular Fats in Deproteinated Potato Wastewater with Different Carbon Sources

    Science.gov (United States)

    Kieliszek, Marek; Jermacz, Karolina; Błażejak, Stanisław

    2017-01-01

    The search for efficient oleaginous microorganisms, which can be an alternative to fossil fuels and biofuels obtained from oilseed crops, has been going on for many years. The suitability of microorganisms in this regard is determined by their ability to biosynthesize lipids with preferred fatty acid profile along with the concurrent utilization of energy-rich industrial waste. In this study, we isolated, characterized, and identified kefir yeast strains using molecular biology techniques. The yeast isolates identified were Candida inconspicua, Debaryomyces hansenii, Kluyveromyces marxianus, Kazachstania unispora, and Zygotorulaspora florentina. We showed that deproteinated potato wastewater, a starch processing industry waste, supplemented with various carbon sources, including lactose and glycerol, is a suitable medium for the growth of yeast, which allows an accumulation of over 20% of lipid substances in its cells. Fatty acid composition primarily depended on the yeast strain and the carbon source used, and, based on our results, most of the strains met the criteria required for the production of biodiesel. In particular, this concerns a significant share of saturated fatty acids, such as C16:0 and C18:0, and unsaturated fatty acids, such as C18:1 and C18:2. The highest efficiency in lipid biosynthesis exceeded 6.3 g L−1. Kazachstania unispora was able to accumulate the high amount of palmitoleic acid. PMID:29098157

  19. Drug resistance to paclitaxel is not only associated with ABCB1 mRNA expression but also with drug accumulation in intracellular compartments in human lung cancer cell lines.

    Science.gov (United States)

    Shimomura, Masanori; Yaoi, Takeshi; Itoh, Kyoko; Kato, Daishiro; Terauchi, Kunihiko; Shimada, Junichi; Fushiki, Shinji

    2012-04-01

    In order to clarify the mechanisms of resistance to paclitaxel in lung cancer, three human lung cancer cell lines which exhibit different sensitivity to paclitaxel were investigated from the following viewpoints: overexpression of ATP-binding cassette, sub-family B, member 1 (ABCB1), mutations on paclitaxel binding site of β-tubulin genes, quantity of polymerized tubulin and the intracellular localization of paclitaxel. ABCB1 expression was evaluated by real-time RT-PCR. No correlations were noted between the ABCB1 expression in the sensitive and resistant cell lines at the mRNA level. No mutations on the paclitaxel binding site of the β-tubulin genes were detected in either the resistant or sensitive cells. Live cell images obtained by confocal laser microscopy revealed that the resistant cell line, RERF-LC-KJ, had more accumulation of Oregon Green® 488 conjugated paclitaxel in the lysosomal and extra-lysosomal compartments of cytoplasm than other cell lines. The results obtained in this study indicated that the changes in the subcellular localization could contribute to the production of paclitaxel resistance in lung cancer cell lines. Further studies should be conducted to elucidate the molecular mechanisms that differentiate the intracellular localization of paclitaxel.

  20. Proteomic and physiological responses of Kineococcus radiotolerans to copper.

    Directory of Open Access Journals (Sweden)

    Christopher E Bagwell

    Full Text Available Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II concentrations (0-1.5 mM in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II concentration in the growth medium (R(2=0.7. Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration.

  1. Proteomic and physiological responses of Kineococcus radiotolerans to copper.

    Science.gov (United States)

    Bagwell, Christopher E; Hixson, Kim K; Milliken, Charles E; Lopez-Ferrer, Daniel; Weitz, Karl K

    2010-08-26

    Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II) concentrations (0-1.5 mM) in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II) concentration in the growth medium (R(2)=0.7). Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration.

  2. Lipophilic ester and amide derivatives of rosmarinic acid protect cells against H2O2-induced DNA damage and apoptosis: The potential role of intracellular accumulation and labile iron chelation

    Directory of Open Access Journals (Sweden)

    Paraskevi S. Gerogianni

    2018-05-01

    Full Text Available Phenolic acids represent abundant components contained in human diet. However, the negative charge in their carboxylic group limits their capacity to diffuse through biological membranes, thus hindering their access to cell interior. In order to promote the diffusion of rosmarinic acid through biological membranes, we synthesized several lipophilic ester- and amide-derivatives of this compound and evaluated their capacity to prevent H2O2-induced DNA damage and apoptosis in cultured human cells. Esterification of the carboxylic moiety with lipophilic groups strongly enhanced the capacity of rosmarinic acid to protect cells. On the other hand, the amide-derivatives were somewhat less effective but exerted less cytotoxicity at high concentrations. Cell uptake experiments, using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS, illustrated different levels of intracellular accumulation among the ester- and amide-derivatives, with the first being more effectively accumulated, probably due to their extensive hydrolysis inside the cells. In conclusion, these results highlight the hitherto unrecognized fundamental importance of derivatization of diet-derived phenolic acids to unveil their biological potential.

  3. Herpes simplex virus type I induces the accumulation of intracellular β-amyloid in autophagic compartments and the inhibition of the non-amyloidogenic pathway in human neuroblastoma cells.

    Science.gov (United States)

    Santana, Soraya; Recuero, Maria; Bullido, Maria Jesús; Valdivieso, Fernando; Aldudo, Jesus

    2012-02-01

    Mounting evidence suggests that herpes simplex virus type 1 (HSV-1) is involved in the pathogenesis of Alzheimer's disease (AD). Epidemiological analyses have shown that HSV-1 is a risk factor for AD in people with at least 1 type 4 allele of the apolipoprotein E gene. Recent studies have also suggested that HSV-1 contributes to the appearance of the biochemical anomalies characteristic of AD brains. In addition, autophagic activity appears to be reduced with aging, and the final stages of autophagy in neurodegenerative process appear to be impaired. The present work reports that HSV-1 provokes the strong intracellular accumulation of both the main species of β-amyloid (Aβ) in the autophagic compartments and that it is associated with a marked inhibition of Aβ secretion. Autophagosomes containing Aβ failed to fuse with lysosomes in HSV-1-infected cells, indicating the impaired degradation of Aβ localized in the autophagic vesicles. In addition, HSV-1 infection was associated with the inhibition of the nonamyloidogenic pathway of amyloid precursor protein (APP) processing without significantly affecting the activity of the secretases involved in the amyloidogenic pathway. Taken together, these data suggest that HSV-1 infection modulates autophagy and amyloid precursor protein processing, contributing to the accumulation of Aβ characteristic of AD. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. The Effect of Copper and Selenium Nanocarboxylates on Biomass Accumulation and Photosynthetic Energy Transduction Efficiency of the Green Algae Chlorella Vulgaris

    Science.gov (United States)

    Mykhaylenko, Natalia F.; Zolotareva, Elena K.

    2017-02-01

    Nanoaquachelates, the nanoparticles with the molecules of water and/or carboxylic acids as ligands, are used in many fields of biotechnology. Ultra-pure nanocarboxylates of microelements are the materials of spatial perspective. In the present work, the effects of copper and selenium nanoaquachelates carboxylated with citric acid on biomass accumulation of the green algae Chlorella vulgaris were examined. Besides, the efficiency of the reactions of the light stage of photosynthesis was estimated by measuring chlorophyll a fluorescence. The addition of 0.67-4 mg L-1 of Cu nanocarboxylates resulted in the increase in Chlorella biomass by ca. 20%; however, their concentrations ranging from 20 to 40 mg L-1 strongly inhibited algal growth after the 12th day of cultivation. Se nanocarboxylates at 0.4-4 mg L-1 concentrations also stimulated the growth of C. vulgaris, and the increase in biomass came up to 40-45%. The addition of Se nanocarboxylates at smaller concentrations (0.07 or 0.2 mg L-1) at first caused the retardation of culture growth, but that effect disappeared after 18-24 days of cultivation. The addition of 2-4 mg L-1 of Cu nanocarboxylates or 0.4-4 mg L-1 of Se nanocarboxylates caused the evident initial increase in such chlorophyll a fluorescence parameters as maximal quantum yield of photosystem II photochemistry ( F v/ F m) and the quantum yield of photosystem II photochemistry in the light-adapted state ( F v'/ F m'). Photochemical fluorescence quenching coefficients declined after 24 days of growth with Cu nanocarboxylates, but they increased after 6 days of the addition of 2 or 4 mg L-1 Se nanocarboxylates. Those alterations affected the overall quantum yield of the photosynthetic electron transport in photosystem II.

  5. The Effect of Copper and Selenium Nanocarboxylates on Biomass Accumulation and Photosynthetic Energy Transduction Efficiency of the Green Algae Chlorella Vulgaris.

    Science.gov (United States)

    Mykhaylenko, Natalia F; Zolotareva, Elena K

    2017-12-01

    Nanoaquachelates, the nanoparticles with the molecules of water and/or carboxylic acids as ligands, are used in many fields of biotechnology. Ultra-pure nanocarboxylates of microelements are the materials of spatial perspective. In the present work, the effects of copper and selenium nanoaquachelates carboxylated with citric acid on biomass accumulation of the green algae Chlorella vulgaris were examined. Besides, the efficiency of the reactions of the light stage of photosynthesis was estimated by measuring chlorophyll a fluorescence. The addition of 0.67-4 mg L -1 of Cu nanocarboxylates resulted in the increase in Chlorella biomass by ca. 20%; however, their concentrations ranging from 20 to 40 mg L -1 strongly inhibited algal growth after the 12th day of cultivation. Se nanocarboxylates at 0.4-4 mg L -1 concentrations also stimulated the growth of C. vulgaris, and the increase in biomass came up to 40-45%. The addition of Se nanocarboxylates at smaller concentrations (0.07 or 0.2 mg L -1 ) at first caused the retardation of culture growth, but that effect disappeared after 18-24 days of cultivation. The addition of 2-4 mg L -1 of Cu nanocarboxylates or 0.4-4 mg L -1 of Se nanocarboxylates caused the evident initial increase in such chlorophyll a fluorescence parameters as maximal quantum yield of photosystem II photochemistry (F v /F m ) and the quantum yield of photosystem II photochemistry in the light-adapted state (F v '/F m '). Photochemical fluorescence quenching coefficients declined after 24 days of growth with Cu nanocarboxylates, but they increased after 6 days of the addition of 2 or 4 mg L -1 Se nanocarboxylates. Those alterations affected the overall quantum yield of the photosynthetic electron transport in photosystem II.

  6. [Copper level and metallothionein-like Cu-binding protein in cultured skin fibroblasts from patients with Menkes' disease and Wilson's disease].

    Science.gov (United States)

    Sato, M; Hayashi, A; Ito, H; Tojo, M; Arima, M

    1984-11-01

    Copper concentration, intracellular copper distribution, and inducibility of metallothionein-like metal-binding protein (MLP) by copper or cadmium addition to culture medium were compared among three types of skin fibroblasts derived from patients with Menkes' disease and Wilson's disease, both exhibiting genetic defects of copper metabolism, and from normal subjects (control). Skin fibroblasts were cultivated in Dulbecco's modified Eagle's medium supplemented with 10% fetal calf serum and antibiotics in 5% CO2 at 37 degrees C. Cells were harvested with rubber-policeman, washed twice with phosphate-buffered saline, pH 7.2, suspended in deionized water, and homogenized. The homogenate from each cell type was used to determine the concentration of copper by atomic absorption spectrophotometry employing graphite-rod atomizer after lyophilization, ashing in HNO3, and coprecipitation with zirconium. Intracellular copper concentration was elevated in Menkes' cells (420 ng Cu/mg of protein) and Wilson's cells (217 ng Cu/mg of protein) than in control cells (90.0 ng Cu/mg of protein), although one of four Wilson's strains showed normal copper level (70.5 ng Cu/mg of protein). Cytosol copper concentration was 5.8-fold higher in Menkes' cells but only 1.3-fold in Wilson's cells than in control cells, and cytosol copper accounted for only 35% of total intracellular copper in Wilson's cells as compared with 68% and 52% in Menkes' and control cells, respectively. These suggest that accumulated copper in each cell type is differently distributed within cells; in Menkes' cells exclusively into cytosol, but in Wilson's cells into particulates rather than cytosol. Elution profiles from Sephadex G-75 columns indicated that most of copper had bound to MLP in Menkes' cells, though no Cu-MLP was detectable in Wilson's or control cells under these experimental conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Unexpected role of the copper transporter ATP7A in PDGF-induced vascular smooth

    Energy Technology Data Exchange (ETDEWEB)

    Ashino, T.; Varadarajan, S.; Urao, N.; Oshikawa, J.; Chen, G. -F.; Wang, H.; Huo, Y.; Finney, L.; Vogt, S.; McKinney, R. D.; Maryon, E. B.; Kaplan, J. H.; Ushio-Fukai, M.; Fukai, T. (Biosciences Division); ( XSD); ( PSC-USR); (Univ. of Illinois at Chicago); (Univ. of Minnesota)

    2010-09-09

    Copper, an essential nutrient, has been implicated in vascular remodeling and atherosclerosis with unknown mechanism. Bioavailability of intracellular copper is regulated not only by the copper importer CTR1 (copper transporter 1) but also by the copper exporter ATP7A (Menkes ATPase), whose function is achieved through copper-dependent translocation from trans-Golgi network (TGN). Platelet-derived growth factor (PDGF) promotes vascular smooth muscle cell (VSMC) migration, a key component of neointimal formation. To determine the role of copper transporter ATP7A in PDGF-induced VSMC migration. Depletion of ATP7A inhibited VSMC migration in response to PDGF or wound scratch in a CTR1/copper-dependent manner. PDGF stimulation promoted ATP7A translocation from the TGN to lipid rafts, which localized at the leading edge, where it colocalized with PDGF receptor and Rac1, in migrating VSMCs. Mechanistically, ATP7A small interfering RNA or CTR small interfering RNA prevented PDGF-induced Rac1 translocation to the leading edge, thereby inhibiting lamellipodia formation. In addition, ATP7A depletion prevented a PDGF-induced decrease in copper level and secretory copper enzyme precursor prolysyl oxidase (Pro-LOX) in lipid raft fraction, as well as PDGF-induced increase in LOX activity. In vivo, ATP7A expression was markedly increased and copper accumulation was observed by synchrotron-based x-ray fluorescence microscopy at neointimal VSMCs in wire injury model. These findings suggest that ATP7A plays an important role in copper-dependent PDGF-stimulated VSMC migration via recruiting Rac1 to lipid rafts at the leading edge, as well as regulating LOX activity. This may contribute to neointimal formation after vascular injury. Our findings provide insight into ATP7A as a novel therapeutic target for vascular remodeling and atherosclerosis.

  8. Effect of the nitrogen status on copper accumulation and pools of metal-binding peptides in the planktonic diatom Thalassiosira pseudonana

    NARCIS (Netherlands)

    Rijstenbil, J.W.; Dehairs, F.; Ehrlich, R.; Wijnholds, J.A.

    1998-01-01

    Effects of the algal cellular nitrogen status on the defence against copper toxicity were studied in batch cultures of the coastal diatom Thalassiosira pseudonana, grown in coastal seawater (Oosterschelde, SW Netherlands; 30 parts per thousand salinity). The media represented nutrient-poor (summer)

  9. Accumulation of heavy metals and As in liver, hair, femur, and lung of Persian jird (Meriones persicus) in Darreh Zereshk copper mine, Iran.

    Science.gov (United States)

    Khazaee, Manoochehr; Hamidian, Amir Hossein; Alizadeh Shabani, Afshin; Ashrafi, Sohrab; Mirjalili, Seyyed Ali Ashghar; Esmaeilzadeh, Esmat

    2016-02-01

    Rodents frequently serve as bioindicator to monitor the quality of the environment. Concentrations of 11 elements (Cd, Co, Ti, Fe, Mn, Cu, Sb, As, Sr, Ni, and Cr) were investigated and compared in liver, hair, femur, and lung of the Persian jird (Meriones persicus) from Darreh Zereshk copper mine, Iran. Metals were determined in different tissues of 39 individuals of Persian jird, collected by snap trap in 2014 from five areas of Darreh Zereshk copper mine. Samples were prepared by wet digestion method, and the contents of elements were analyzed with ICP-OES (VARIAN, 725-ES) instrument. Cadmium, Sb, and Co were below the limit of detection, and Mn and As were found only in hair and liver tissues. We detected the highest concentration of Cu, As, Ti, Fe, Mn, Cr, and Ni in hair in comparison with other tissues. Significant higher levels of Ti in femur and hair; Fe in liver and hair; Mn in liver; As in hair; Sr in lung; Cr in lung, hair, femur, and liver; Cu in femur; and Ni in liver and lung tissues were observed in females. Nearly all element concentrations in the tissues of Persian jird from flotation site, Darreh Zereshk and Hasan Abad villages and leaching site (mining areas) were higher than those from tailing dump site (reference site). We found the highest concentrations of As in liver and hair; Ni and Cr in liver, hair, and lung; and Sr in lung and hair tissues of Persian jird in leaching site. We tried to specify the status of elements before fully exploitation of Darreh Zereshk copper mine by using bioindicator species. Based on our achievements, initial activities did not strongly pollute the surrounded environment of the mine. The high abundance of Persian jird as well as their several proper features makes them a suitable species for biomonitoring programs especially for further studies will be performed after full exploitation of Darreh Zereshk copper mine.

  10. Functional genomics of intracellular bacteria.

    Science.gov (United States)

    de Barsy, Marie; Greub, Gilbert

    2013-07-01

    During the genomic era, a large amount of whole-genome sequences accumulated, which identified many hypothetical proteins of unknown function. Rapidly, functional genomics, which is the research domain that assign a function to a given gene product, has thus been developed. Functional genomics of intracellular pathogenic bacteria exhibit specific peculiarities due to the fastidious growth of most of these intracellular micro-organisms, due to the close interaction with the host cell, due to the risk of contamination of experiments with host cell proteins and, for some strict intracellular bacteria such as Chlamydia, due to the absence of simple genetic system to manipulate the bacterial genome. To identify virulence factors of intracellular pathogenic bacteria, functional genomics often rely on bioinformatic analyses compared with model organisms such as Escherichia coli and Bacillus subtilis. The use of heterologous expression is another common approach. Given the intracellular lifestyle and the many effectors that are used by the intracellular bacteria to corrupt host cell functions, functional genomics is also often targeting the identification of new effectors such as those of the T4SS of Brucella and Legionella.

  11. A horizontally gene transferred copper resistance locus confers hyper-resistance to antibacterial copper toxicity and enables survival of community acquired methicillin resistant Staphylococcus aureus USA300 in macrophages.

    Science.gov (United States)

    Purves, Joanne; Thomas, Jamie; Riboldi, Gustavo P; Zapotoczna, Marta; Tarrant, Emma; Andrew, Peter W; Londoño, Alejandra; Planet, Paul J; Geoghegan, Joan A; Waldron, Kevin J; Morrissey, Julie A

    2018-03-09

    Excess copper is highly toxic and forms part of the host innate immune system's antibacterial arsenal, accumulating at sites of infection and acting within macrophages to kill engulfed pathogens. We show for the first time that a novel, horizontally gene transferred copper resistance locus (copXL), uniquely associated with the SCCmec elements of the highly virulent, epidemic, community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) USA300, confers copper hyper-resistance. These genes are additional to existing core genome copper resistance mechanisms, and are not found in typical S. aureus lineages, but are increasingly identified in emerging pathogenic isolates. Our data show that CopX, a putative P 1B-3 -ATPase efflux transporter, and CopL, a novel lipoprotein, confer copper hyper-resistance compared to typical S. aureus strains. The copXL genes form an operon that is tightly repressed in low copper environments by the copper regulator CsoR. Significantly, CopX and CopL are important for S. aureus USA300 intracellular survival within macrophages. Therefore, the emergence of new S. aureus clones with the copXL locus has significant implications for public health because these genes confer increased resistance to antibacterial copper toxicity, enhancing bacterial fitness by altering S. aureus interaction with innate immunity. © 2018 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Copper Tolerance and Characterization of a Copper-Responsive Operon, copYAZ, in an M1T1 Clinical Strain of Streptococcus pyogenes.

    Science.gov (United States)

    Young, Christie A; Gordon, Lily D; Fang, Zhong; Holder, Robert C; Reid, Sean D

    2015-08-01

    Infection with Streptococcus pyogenes is associated with a breadth of clinical manifestations ranging from mild pharyngitis to severe necrotizing fasciitis. Elevated levels of intracellular copper are highly toxic to this bacterium, and thus, the microbe must tightly regulate the level of this metal ion by one or more mechanisms, which have, to date, not been clearly defined. In this study, we have identified two virulence mechanisms by which S. pyogenes protects itself against copper toxicity. We defined a set of putative genes, copY (for a regulator), copA (for a P1-type ATPase), and copZ (for a copper chaperone), whose expression is regulated by copper. Our results indicate that these genes are highly conserved among a range of clinical S. pyogenes isolates. The copY, copA, and copZ genes are induced by copper and are transcribed as a single unit. Heterologous expression assays revealed that S. pyogenes CopA can confer copper tolerance in a copper-sensitive Escherichia coli mutant by preventing the accumulation of toxic levels of copper, a finding that is consistent with a role for CopA in copper export. Evaluation of the effect of copper stress on S. pyogenes in a planktonic or biofilm state revealed that biofilms may aid in protection during initial exposure to copper. However, copper stress appears to prevent the shift from the planktonic to the biofilm state. Therefore, our results indicate that S. pyogenes may use several virulence mechanisms, including altered gene expression and a transition to and from planktonic and biofilm states, to promote survival during copper stress. Bacterial pathogens encounter multiple stressors at the host-pathogen interface. This study evaluates a virulence mechanism(s) utilized by S. pyogenes to combat copper at sites of infection. A better understanding of pathogen tolerance to stressors such as copper is necessary to determine how host-pathogen interactions impact bacterial survival during infections. These insights may

  13. Effects on the accumulation of calcium, magnesium, iron, manganese, copper and zinc of adding the two inorganic forms of selenium to solution cultures of Zea mays.

    Science.gov (United States)

    Longchamp, M; Angeli, N; Castrec-Rouelle, M

    2016-01-01

    The addition of selenate or selenite to common fertilizers for crop production could be an effective way of producing selenium-rich food and feed. However, this would be feasible only if the increase in plant selenium (Se) content did not negatively influence the uptake of other essential elements. We therefore need to understand the interactions between Se and other major and trace elements during uptake by the plant. This study aimed to evaluate the influence of inorganic forms of Se on the accumulation of selected macronutrients (Ca and Mg) and micronutrients (Fe, Zn, Mn and Cu). Those essential elements are involved in the oxidative balance of cells. Zea mays seedlings were grown hydroponically in growth chambers in nutrient solutions to which we added 10, 50 or 1000 μg.L(-1) of selenate and/or selenite. Cation accumulation was significantly affected by the addition of 50 μg.L(-1) or 1000 μg.L(-1) Se, but not by the presence of 10 μg.L(-1) of Se in the nutrient solution. The highest concentration (1000 μg.L(-1)) of Se in the nutrient solution affected the accumulation of essential cations in Zea mays: selenate tended to increase the accumulation of Mg, Zn and Mn, whereas a selenate/selenite mixture tended to decrease the accumulation of Ca, Mg, Zn and Mn. Only Fe accumulation was unaffected by Se whatever its form or concentration. Selenium may also affect the distribution of cations on Zea mays. For example, levels of Mg and Zn translocation to the shoots were lower in the presence of selenite. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  14. Characterization of copper transport in gill cells of a mangrove crab Ucides cordatus

    Energy Technology Data Exchange (ETDEWEB)

    Sá, M.G. [Biosciences Institute, Department of Physiology, University of São Paulo, Rua do Matão, Travessa 14, 101, São Paulo 05508-900, SP (Brazil); Zanotto, F.P., E-mail: fzanotto@usp.br [Biosciences Institute, Department of Physiology, University of São Paulo, Rua do Matão, Travessa 14, 101, São Paulo 05508-900, SP (Brazil); Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Rua Três de Maio 100, Sao Paulo 04044-020 (Brazil)

    2013-11-15

    Highlights: •Copper transport in gill cells of a mangrove crab Ucides cordatus is dependent of calcium. •Copper transport mechanism is ATP-dependent. •Transport was monitored second by second during 300 s. -- Abstract: The branchial epithelium of crustaceans is exposed to the environment and is the first site affected by metal pollution. The aim of this work was to characterize copper (Cu) transport using a fluorescent dye, Phen Green, in gill cells of a hypo-hyper-regulator mangrove crab Ucides cordatus. The results showed that added extracellular CuCl{sub 2} (0, 0.025, 0.150, 0.275, 0.550 and 1.110 μM) showed typical Michaelis–Menten transport for Cu in anterior and posterior gill cells (V{sub max} for anterior and posterior gills: 0.41 ± 0.12 and 1.76 ± 0.27 intracellular Cu in μM × 22.10{sup 4} cells{sup −1} × 300 s{sup −1} respectively and K{sub m} values: 0.44 ± 0.04 and 0.32 ± 0.13 μM, respectively). Intracellular Cu was significantly higher for posterior gill cells compared to anterior gill cells, suggesting differential accumulation for each gill type. Extracellular Ca at 20 mM decreased cellular Cu transport for both anterior and posterior gill cells. Nifedipine and verapamil, calcium channel inhibitors from plasma membrane, decreased Cu transport and affected K{sub m} for both gills. These results could be due to a competition between Cu and Ca. Amiloride, a Na/Ca exchanger inhibitor, as well as bafilomycin, a proton pump inhibitor, caused a decrease of intracellular Cu compared to control. Ouabain and KB-R 7943, acting on Na homeostasis, similarly decreased intracellular Cu in both gill cells. Besides that, gill cells exposed to ATP and Cu simultaneously, showed an increase in intracellular copper, which was inhibited by vanadate, an inhibitor of P-type ATPase. These results suggest either the presence of a Cu-ATPase in crab gill cells, responsible for Cu influx, or the effect of a change in electrochemical membrane potential that

  15. Study on accumulation mechanism of lead and copper in metal-hypertolerant fern, Athyrium yokoscense, by micro-XRF analysis utilizing synchrotron radiation

    International Nuclear Information System (INIS)

    Mitsuo, Sakiko; Kashiwabara, Teruhiko; Hokura, Akiko; Nakai, Izumi; Kitajima, Nobuyuki; Goto, Fumiyuki; Yoshihara, Toshihiro; Abe, Tomoko

    2009-01-01

    Athyrium yokoscense is a plant which accumulates high level of heavy metals such as Cu, Zn, Pb and Cd, and is expected to be used for phytoremediation. This paper reports the distribution and the chemical forms of Pb and Cu in underground parts (root and old leaf stalks) of the metal-hypertolerant fern, A. yokoscense, by synchrotron radiation micro-XRF imaging and micro-XANES analyses. The old and new tissues of root and leaf stalks were prepared for micro-XRF analysis. The XRF imaging of the young root revealed that K, Cu and Zn were distributed in whole area of cross-section, whereas Pb was found in a certain part of the epidermal tissue. For the old root, Pb and Cu were mainly distributed in the cell wall of the whole tissue. The distribution of heavy metal in old tissue is different from those of new tissue, and consequently it was assumed that the root at different age have different heavy metal accumulation mechanism. Alternatively, for the old leaf stalks, Cu and Pb were highly accumulated in a specific part located around the vascular tissue. Cu K-edge micro-XANES analysis indicated that the chemical form of Cu at the Cu accumulating point was Cu (II). (author)

  16. Influence of arbuscular mycorrhizal fungi and copper on growth, accumulation of osmolyte, mineral nutrition and antioxidant enzyme activity of pepper (Capsicum annuum L.).

    Science.gov (United States)

    Abdel Latef, Arafat Abdel Hamed

    2011-08-01

    The effect of arbuscular mycorrhizal (AM) fungi inoculation on pepper (Capsicum annuum L. cv. Zhongjiao 105) plant growth and on some physiological parameters in response to increasing soil Cu concentrations was studied. Treatments consisted of inoculation or not with Glomus mosseae and the addition of Cu to soil at the concentrations of 0 (control), 2 (low), 4 (medium), and 8 (high) mM CuSO(4). AM fungal inoculation decreased Cu concentrations in plant organs and promoted biomass yields as well as the contents of chlorophyll, soluble sugar, total protein, and the concentrations of P, K, Ca, and Mg. Plants grown in high Cu concentration exhibited a Cu-induced proline accumulation and also an increase in total free amino acid contents; however, both were lower in mycorrhizal pepper. Cu-induced oxidative stress by increasing lipid peroxidation rates and the activity of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, and AM symbiosis enhanced these antioxidant enzyme activities and decreased oxidative damage to lipids. In conclusion G. mosseae was able to maintain an efficient symbiosis with pepper plants in contaminated Cu soils, improving plant growth under these conditions, which is likely to be due to reduced Cu accumulation in plant tissues, reduced oxidative stress and damage to lipids, or enhanced antioxidant capacity.

  17. Inducible plasmid-mediated copper resistance in Escherichia coli.

    Science.gov (United States)

    Rouch, D; Camakaris, J; Lee, B T; Luke, R K

    1985-04-01

    The copper resistance in Escherichia coli determined by plasmid pRJ1004 is inducible. The level of resistance is proportional to the inducing dose of copper. The level of copper resistance in induced and uninduced cells changes with the growth phase of the culture. Induced resistant cells accumulate less copper than uninduced cells, so that reduced accumulation may be the mechanism of resistance. We propose that the inducible plasmid-coded copper resistance interacts with the normal metabolism of the cell to protect against toxic levels of copper while allowing continued operation of copper-dependent functions.

  18. Coping with copper

    DEFF Research Database (Denmark)

    Nunes, Ines Marques; Jacquiod, Samuel Jehan Auguste; Brejnrod, Asker Daniel

    2016-01-01

    Copper has been intensively used in industry and agriculture since mid-18(th) century and is currently accumulating in soils. We investigated the diversity of potential active bacteria by 16S rRNA gene transcript amplicon sequencing in a temperate grassland soil subjected to century-long exposure...

  19. Zinc, copper, or cerium accumulation from metal oxide nanoparticles or ions in sweet potato: Yield effects and projected dietary intake from consumption.

    Science.gov (United States)

    Bradfield, Scott J; Kumar, Pawan; White, Jason C; Ebbs, Stephen D

    2017-01-01

    The potential release of metal oxide engineered nanoparticles (ENP) into agricultural systems has created the need to evaluate the impact of these materials on crop yield and food safety. The study here grew sweet potato (Ipomoea batatas) to maturity in field microcosms using substrate amended with three concentrations (100, 500 or 1000 mg kg DW -1 ) of either nZnO, nCuO, or nCeO 2 or equivalent amounts of Zn 2+ , Cu 2+ , or Ce 4+ . Adverse effects on tuber biomass were observed only for the highest concentration of Zn or Cu applied. Exposure to both forms of Ce had no adverse effect on yield and a slight positive benefit at higher concentrations on tuber diameter. The three metals accumulated in both the peel and flesh of the sweet potato tubers, with concentrations higher in the peel than the flesh for each element. For Zn, >70% of the metal was in the flesh and for Cu >50%. The peels retained 75-95% of Ce in the tubers. The projected dietary intake of each metal by seven age-mass classes from child to adult only exceeded the oral reference dose for chronic toxicity in a scenario where children consumed tubers grown at the highest metal concentration. The results throughout were generally not different between the ENP- and ionic-treatments, suggesting that the added ENPs underwent dissolution to release their component ions prior to accumulation. The results offer insight into the fate and impact of these ENPs in soils. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  20. Copper transport.

    Science.gov (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  1. The copper-transporting ATPase pump and its potential role in copper-tolerance

    Science.gov (United States)

    Katie Ohno; C.A. Clausen; Frederick Green; G. Stanosz

    2016-01-01

    Copper-tolerant brown-rot decay fungi exploit intricate mechanisms to neutralize the efficacy of copper-containing preservative formulations. The production and accumulation oxalate is the most widely recognized theory regarding the mechanism of copper-tolerance in these fungi. The role of oxalate, however, may be only one part of a series of necessary components...

  2. Copper isotope fractionation by desert shrubs

    International Nuclear Information System (INIS)

    Navarrete, Jesica U.; Viveros, Marian; Ellzey, Joanne T.; Borrok, David M.

    2011-01-01

    Copper has two naturally occurring stable isotopes of masses 63 and 65 which can undergo mass dependent fractionation during various biotic and abiotic chemical reactions. These interactions and their resulting Cu isotope fractionations can be used to determine the mechanisms involved in the cycling of Cu in natural systems. In this study, Cu isotope changes were investigated at the organismal level in the metal-accumulating desert plant, Prosopis pubescens. Initial results suggest that the lighter Cu isotope was preferentially incorporated into the leaves of the plant, which may suggest that Cu was actively transported via intracellular proteins. The roots and stems show a smaller degree of Cu isotope fractionation and the direction and magnitude of the fractionations was dependent upon the levels of Cu exposure. Based on this and previous work with bacteria and yeast, a trend is emerging that suggests the lighter Cu isotope is preferentially incorporated into biological components, while the heavier Cu isotope tends to become enriched in aqueous solutions. In bacteria, plants and animals, intracellular Cu concentrations are strictly regulated via dozens of enzymes that can bind, transport, and store Cu. Many of these enzymes reduce Cu(II) to Cu(I). These initial results seem to fit into a broader picture of Cu isotope cycling in natural systems where oxidation/reduction reactions are fundamental in controlling the distributions of Cu isotopes.

  3. APPLICATION OF METAL RESISTANT BACTERIA BY MUTATIONAL ENHANCMENT TECHNIQUE FOR BIOREMEDIATION OF COPPER AND ZINC FROM INDUSTRIAL WASTES

    Directory of Open Access Journals (Sweden)

    M. R. Shakibaie ، A. Khosravan ، A. Frahmand ، S. Zare

    2008-10-01

    Full Text Available In this research, using mutation in the metal resistant bacteria, the bioremediation of the copper and zinc from copper factory effluents was investigated. Wastewater effluents from flocculation and rolling mill sections of a factory in the city of Kerman were collected and used for further experiments. 20 strains of Pseudomonas spp. were isolated from soil and effluents surrounding factory and identified by microbiological methods. Minimum inhibitory concentrations for copper (Cu and zinc (Zn were determined by agar dilution method. Those strains that exhibited highest minimum inhibitory concentrations values to the metals (5mM were subjected to 400-3200 mg/L concentrations of the three mutagenic agents, acriflavine, acridine orange and ethidium bromide. After determination of subinhibitory concentrations, the minimum inhibitory concentrations values for copper and zinc metal ions were again determined, which showed more than 10 fold increase in minimum inhibitory concentrations value (10 mM for Cu and 20 mM for Zn with P≤0.05. The atomic absorption spectroscopy of dried biomass obtained from resistant strains after exposure to mutagenic agents revealed that strains 13 accumulate the highest amount of intracellular copper (0.35% Cu/mg dried biomass and strain 10 showed highest accumulation of zinc (0.3% Zn/mg dried biomass respectively with P≤0.05. From above results it was concluded that the treatment of industrial waste containing heavy metals by artificially mutated bacteria may be appropriate solution for effluent disposal problems.

  4. The effects of copper proximity on oxalate production in Fibroporia radiculosa

    Science.gov (United States)

    Katie M. Jenkins; Carol A. Clausen; Frederick Green III

    2014-01-01

    Copper remains a key component used in wood preservatives available today. However, the observed tolerance of several critical wood rotting organisms continues to be problematic. Tolerance to copper has been linked to the production and accumulation of oxalate, which precipitates copper into insoluble copper-oxalate crystals, thus inactivating copper ions. The purpose...

  5. Investigating Internalization and Intracellular Trafficking of GPCRs

    DEFF Research Database (Denmark)

    Foster, Simon R; Bräuner-Osborne, Hans

    2017-01-01

    for signal transduction. One of the major mechanisms for GPCR regulation involves their endocytic trafficking, which serves to internalize the receptors from the plasma membrane and thereby attenuate G protein-dependent signaling. However, there is accumulating evidence to suggest that GPCRs can signal...... independently of G proteins, as well as from intracellular compartments including endosomes. It is in this context that receptor internalization and intracellular trafficking have attracted renewed interest within the GPCR field. In this chapter, we will review the current understanding and methodologies...... that have been used to investigate internalization and intracellular signaling of GPCRs, with a particular focus on emerging real-time techniques. These recent developments have improved our understanding of the complexities of GPCR internalization and intracellular signaling and suggest that the broader...

  6. Clusterin (Apolipoprotein J), a Molecular Chaperone That Facilitates Degradation of the Copper-ATPases ATP7A and ATP7B

    NARCIS (Netherlands)

    Materia, Stephanie; Cater, Michael A.; Klomp, Leo W. J.; Mercer, Julian F. B.; La Fontaine, Sharon

    2011-01-01

    The copper-transporting P1B-type ATPases (Cu-ATPases) ATP7A and ATP7B are key regulators of physiological copper levels. They function to maintain intracellular copper homeostasis by delivering copper to secretory compartments and by trafficking toward the cell periphery to export excess copper.

  7. A Plasmodium falciparum copper-binding membrane protein with copper transport motifs

    Directory of Open Access Journals (Sweden)

    Choveaux David L

    2012-11-01

    Full Text Available Abstract Background Copper is an essential catalytic co-factor for metabolically important cellular enzymes, such as cytochrome-c oxidase. Eukaryotic cells acquire copper through a copper transport protein and distribute intracellular copper using molecular chaperones. The copper chelator, neocuproine, inhibits Plasmodium falciparum ring-to-trophozoite transition in vitro, indicating a copper requirement for malaria parasite development. How the malaria parasite acquires or secretes copper still remains to be fully elucidated. Methods PlasmoDB was searched for sequences corresponding to candidate P. falciparum copper-requiring proteins. The amino terminal domain of a putative P. falciparum copper transport protein was cloned and expressed as a maltose binding fusion protein. The copper binding ability of this protein was examined. Copper transport protein-specific anti-peptide antibodies were generated in chickens and used to establish native protein localization in P. falciparum parasites by immunofluorescence microscopy. Results Six P. falciparum copper-requiring protein orthologs and a candidate P. falciparum copper transport protein (PF14_0369, containing characteristic copper transport protein features, were identified in PlasmoDB. The recombinant amino terminal domain of the transport protein bound reduced copper in vitro and within Escherichia coli cells during recombinant expression. Immunolocalization studies tracked the copper binding protein translocating from the erythrocyte plasma membrane in early ring stage to a parasite membrane as the parasites developed to schizonts. The protein appears to be a PEXEL-negative membrane protein. Conclusion Plasmodium falciparum parasites express a native protein with copper transporter characteristics that binds copper in vitro. Localization of the protein to the erythrocyte and parasite plasma membranes could provide a mechanism for the delivery of novel anti-malarial compounds.

  8. Copper: From neurotransmission to neuroproteostasis

    Directory of Open Access Journals (Sweden)

    Carlos M Opazo

    2014-07-01

    Full Text Available Copper is critical for the Central Nervous System (CNS development and function. In particular, different studies have shown the effect of copper at brain synapses, where it inhibits Long Term Potentation (LTP and receptor pharmacology. Paradoxically, according to recent studies copper is required for a normal LTP response. Copper is released at the synaptic cleft, where it blocks glutamate receptors, which explain its blocking effects on excitatory neurotransmission. Our results indicate that copper also enhances neurotransmission through the accumulation of PSD95 protein, which increase the levels of AMPA receptors located at the plasma membrane of the post-synaptic density. Thus, our findings represent a novel mechanism for the action of copper, which may have implications for the neurophysiology and neuropathology of the CNS. These data indicate that synaptic configuration is sensitive to transient changes in transition metal homeostasis. Our results suggest that copper increases GluA1 subunit levels of the AMPA receptor through the anchorage of AMPA receptors to the plasma membrane as a result of PSD-95 accumulation. Here, we will review the role of copper on neurotransmission of CNS neurons. In addition, we will discuss the potential mechanisms by which copper could modulate neuronal proteostasis (neuroproteostasis in the CNS with focus in the Ubiquitin Proteasome System, which is particularly relevant to neurological disorders such Alzheimer’s disease (AD where copper and protein dyshomeostasis may contribute to neurodegeneration. An understanding of these mechanisms may ultimately lead to the development of novel therapeutic approaches to control metal and synaptic alterations observed in AD patients.

  9. Copper hypersensitivity

    DEFF Research Database (Denmark)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-01-01

    . As a metal, it possesses many of the same qualities as nickel, which is a known strong sensitizer. Cumulative data on subjects with presumed related symptoms and/or suspected exposure showed that a weighted average of 3.8% had a positive patch test reaction to copper. We conclude that copper is a very weak...... hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  10. Copper (II)

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    ABSTRACT: A Schiff base was prepared from the reaction of 2 - amino - 3 – methylbutanoic acid and 2, 4 - pentanedione. The reaction of the prepared Schiff base with ethanolic solution of copper (II) chloride formed diaquo bis( N – 2 – amino – 3 - methylbutyl - 2, 4 - pentanedionato) copper (II) complex. The Schiff base is ...

  11. Comparative genomic analyses of copper transporters and cuproproteomes reveal evolutionary dynamics of copper utilization and its link to oxygen.

    Directory of Open Access Journals (Sweden)

    Perry G Ridge

    2008-01-01

    Full Text Available Copper is an essential trace element in many organisms and is utilized in all domains of life. It is often used as a cofactor of redox proteins, but is also a toxic metal ion. Intracellular copper must be carefully handled to prevent the formation of reactive oxygen species which pose a threat to DNA, lipids, and proteins. In this work, we examined patterns of copper utilization in prokaryotes by analyzing the occurrence of copper transporters and copper-containing proteins. Many organisms, including those that lack copper-dependent proteins, had copper exporters, likely to protect against copper ions that inadvertently enter the cell. We found that copper use is widespread among prokaryotes, but also identified several phyla that lack cuproproteins. This is in contrast to the use of other trace elements, such as selenium, which shows more scattered and reduced usage, yet larger selenoproteomes. Copper transporters had different patterns of occurrence than cuproproteins, suggesting that the pathways of copper utilization and copper detoxification are independent of each other. We present evidence that organisms living in oxygen-rich environments utilize copper, whereas the majority of anaerobic organisms do not. In addition, among copper users, cuproproteomes of aerobic organisms were larger than those of anaerobic organisms. Prokaryotic cuproproteomes were small and dominated by a single protein, cytochrome c oxidase. The data are consistent with the idea that proteins evolved to utilize copper following the oxygenation of the Earth.

  12. Copper-associated hepatitis in dogs; pathogenesis, diagnosis and treatment

    NARCIS (Netherlands)

    Dirksen, K.|info:eu-repo/dai/nl/412424428

    2016-01-01

    Copper is an essential trace element for living organisms, but can have deleterious consequences when present in excess. Because the liver has a central role in copper metabolism, this is the predominant organ affected. Copper-accumulating disorders are recognized as hereditary diseases in man and

  13. Uptake and internalisation of copper by three marine microalgae: comparison of copper-sensitive and copper-tolerant species.

    Science.gov (United States)

    Levy, Jacqueline L; Angel, Brad M; Stauber, Jennifer L; Poon, Wing L; Simpson, Stuart L; Cheng, Shuk Han; Jolley, Dianne F

    2008-08-29

    Although it has been well established that different species of marine algae have different sensitivities to metals, our understanding of the physiological and biochemical basis for these differences is limited. This study investigated copper adsorption and internalisation in three algal species with differing sensitivities to copper. The diatom Phaeodactylum tricornutum was particularly sensitive to copper, with a 72-h IC50 (concentration of copper to inhibit growth rate by 50%) of 8.0 microg Cu L(-1), compared to the green algae Tetraselmis sp. (72-h IC50 47 microg Cu L(-1)) and Dunaliella tertiolecta (72-h IC50 530 microg Cu L(-1)). At these IC50 concentrations, Tetraselmis sp. had much higher intracellular copper (1.97+/-0.01 x 10(-13)g Cu cell(-1)) than P. tricornutum (0.23+/-0.19 x 10(-13)g Cu cell(-1)) and D. tertiolecta (0.59+/-0.05 x 10(-13)g Cu cell(-1)), suggesting that Tetraselmis sp. effectively detoxifies copper within the cell. By contrast, at the same external copper concentration (50 microg L(-1)), D. tertiolecta appears to better exclude copper than Tetraselmis sp. by having a slower copper internalisation rate and lower internal copper concentrations at equivalent extracellular concentrations. The results suggest that the use of internal copper concentrations and net uptake rates alone cannot explain differences in species-sensitivity for different algal species. Model prediction of copper toxicity to marine biota and understanding fundamental differences in species-sensitivity will require, not just an understanding of water quality parameters and copper-cell binding, but also further knowledge of cellular detoxification mechanisms.

  14. Intracellular mechanisms of solar water disinfection

    Science.gov (United States)

    Castro-Alférez, María; Polo-López, María Inmaculada; Fernández-Ibáñez, Pilar

    2016-12-01

    Solar water disinfection (SODIS) is a zero-cost intervention measure to disinfect drinking water in areas of poor access to improved water sources, used by more than 6 million people in the world. The bactericidal action of solar radiation in water has been widely proven, nevertheless the causes for this remain still unclear. Scientific literature points out that generation of reactive oxygen species (ROS) inside microorganisms promoted by solar light absorption is the main reason. For the first time, this work reports on the experimental measurement of accumulated intracellular ROS in E. coli during solar irradiation. For this experimental achievement, a modified protocol based on the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA), widely used for oxidative stress in eukaryotic cells, has been tested and validated for E. coli. Our results demonstrate that ROS and their accumulated oxidative damages at intracellular level are key in solar water disinfection.

  15. The copYAZ Operon Functions in Copper Efflux, Biofilm Formation, Genetic Transformation, and Stress Tolerance in Streptococcus mutans

    Science.gov (United States)

    Singh, Kamna; Senadheera, Dilani B.; Lévesque, Céline M.

    2015-01-01

    ABSTRACT In bacteria, copper homeostasis is closely monitored to ensure proper cellular functions while avoiding cell damage. Most Gram-positive bacteria utilize the copYABZ operon for copper homeostasis, where copA and copB encode copper-transporting P-type ATPases, whereas copY and copZ regulate the expression of the cop operon. Streptococcus mutans is a biofilm-forming oral pathogen that harbors a putative copper-transporting copYAZ operon. Here, we characterized the role of copYAZ operon in the physiology of S. mutans and delineated the mechanisms of copper-induced toxicity in this bacterium. We observed that copper induced toxicity in S. mutans cells by generating oxidative stress and disrupting their membrane potential. Deletion of the copYAZ operon in S. mutans strain UA159 resulted in reduced cell viability under copper, acid, and oxidative stress relative to the viability of the wild type under these conditions. Furthermore, the ability of S. mutans to form biofilms and develop genetic competence was impaired under copper stress. Briefly, copper stress significantly reduced cell adherence and total biofilm biomass, concomitantly repressing the transcription of the gtfB, gtfC, gtfD, gbpB, and gbpC genes, whose products have roles in maintaining the structural and/or functional integrity of the S. mutans biofilm. Furthermore, supplementation with copper or loss of copYAZ resulted in significant reductions in transformability and in the transcription of competence-associated genes. Copper transport assays revealed that the ΔcopYAZ strain accrued significantly large amounts of intracellular copper compared with the amount of copper accumulation in the wild-type strain, thereby demonstrating a role for CopYAZ in the copper efflux of S. mutans. The complementation of the CopYAZ system restored copper expulsion, membrane potential, and stress tolerance in the copYAZ-null mutant. Taking these results collectively, we have established the function of the S. mutans

  16. The copYAZ Operon Functions in Copper Efflux, Biofilm Formation, Genetic Transformation, and Stress Tolerance in Streptococcus mutans.

    Science.gov (United States)

    Singh, Kamna; Senadheera, Dilani B; Lévesque, Céline M; Cvitkovitch, Dennis G

    2015-08-01

    In bacteria, copper homeostasis is closely monitored to ensure proper cellular functions while avoiding cell damage. Most Gram-positive bacteria utilize the copYABZ operon for copper homeostasis, where copA and copB encode copper-transporting P-type ATPases, whereas copY and copZ regulate the expression of the cop operon. Streptococcus mutans is a biofilm-forming oral pathogen that harbors a putative copper-transporting copYAZ operon. Here, we characterized the role of copYAZ operon in the physiology of S. mutans and delineated the mechanisms of copper-induced toxicity in this bacterium. We observed that copper induced toxicity in S. mutans cells by generating oxidative stress and disrupting their membrane potential. Deletion of the copYAZ operon in S. mutans strain UA159 resulted in reduced cell viability under copper, acid, and oxidative stress relative to the viability of the wild type under these conditions. Furthermore, the ability of S. mutans to form biofilms and develop genetic competence was impaired under copper stress. Briefly, copper stress significantly reduced cell adherence and total biofilm biomass, concomitantly repressing the transcription of the gtfB, gtfC, gtfD, gbpB, and gbpC genes, whose products have roles in maintaining the structural and/or functional integrity of the S. mutans biofilm. Furthermore, supplementation with copper or loss of copYAZ resulted in significant reductions in transformability and in the transcription of competence-associated genes. Copper transport assays revealed that the ΔcopYAZ strain accrued significantly large amounts of intracellular copper compared with the amount of copper accumulation in the wild-type strain, thereby demonstrating a role for CopYAZ in the copper efflux of S. mutans. The complementation of the CopYAZ system restored copper expulsion, membrane potential, and stress tolerance in the copYAZ-null mutant. Taking these results collectively, we have established the function of the S. mutans Cop

  17. Canine Models for Copper Homeostasis Disorders

    Directory of Open Access Journals (Sweden)

    Xiaoyan Wu

    2016-02-01

    Full Text Available Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted.

  18. Mechanisms underlying reductant-induced reactive oxygen species formation by anticancer copper(II) compounds

    OpenAIRE

    Kowol, Christian R.; Heffeter, Petra; Miklos, Walter; Gille, Lars; Trondl, Robert; Cappellacci, Loredana; Berger, Walter; Keppler, Bernhard K.

    2011-01-01

    Intracellular generation of reactive oxygen species (ROS) via thiol-mediated reduction of copper(II) to copper(I) has been assumed as the major mechanism underlying the anticancer activity of copper(II) complexes. The aim of this study was to compare the anticancer potential of copper(II) complexes of Triapine (3-amino-pyridine-2-carboxaldehyde thiosemicarbazone; currently in phase II clinical trials) and its terminally dimethylated derivative with that of 2-formylpyridine thiosemicarbazone a...

  19. Analysis of copper flows in China from 1975 to 2010.

    Science.gov (United States)

    Zhang, Ling; Yang, Jiameng; Cai, Zhijian; Yuan, Zengwei

    2014-04-15

    By applying substance flow analysis (SFA), the paper attempts to illustrate how copper utilization pattern has changed in the anthroposphere of China from 1975 to 2010. An analytical framework is firstly established and the detailed copper cycles of the specific years 1975, 1985, 1995, 2005 and 2010 are then characterized. Major conclusions include the following: (1) Chinese copper industry has made significant progress driven by large domestic copper demand since 1970s, especially after 1990s. Also the structure of copper industry has shifted from a basic industry to a processing industry. The share of secondary copper production in total refined copper has risen from 20% in 1975 to 38% in 2010; (2) the Chinese society has experienced a rapid copper accumulation since 1990s. The annual input flow to use stage jumped from only 334 Gg (that is 0.36 kg per capita copper consumption) in 1975 to 7,916 Gg (5.90 kg per capita) in 2010; (3) a large amount of copper has to be imported to meet the huge demand, mainly involving in copper concentrate, refined copper and copper scrap. And the NIR (Net Import Ratio) of the three was 53.0%, 38.7% and 63.0% in 2010, respectively; (4) domestically produced copper scrap increased from 74.5 Gg in 1975 to 711.2 Gg in 2010. Comparing it with import scrap and domestic new scrap we found that at current stage the in-use stock is still too small to generate high quantities of copper scrap for domestic secondary copper production. (5) Major copper losses occurred through copper Mining, Refining and WM&R, with the Mining exhibited the lowest copper utilization efficiency (CUE) among the three processes, and may have the great potential for increasing copper utilization rate in China. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  20. Macrophage defense mechanisms against intracellular bacteria.

    Science.gov (United States)

    Weiss, Günter; Schaible, Ulrich E

    2015-03-01

    Macrophages and neutrophils play a decisive role in host responses to intracellular bacteria including the agent of tuberculosis (TB), Mycobacterium tuberculosis as they represent the forefront of innate immune defense against bacterial invaders. At the same time, these phagocytes are also primary targets of intracellular bacteria to be abused as host cells. Their efficacy to contain and eliminate intracellular M. tuberculosis decides whether a patient initially becomes infected or not. However, when the infection becomes chronic or even latent (as in the case of TB) despite development of specific immune activation, phagocytes have also important effector functions. Macrophages have evolved a myriad of defense strategies to combat infection with intracellular bacteria such as M. tuberculosis. These include induction of toxic anti-microbial effectors such as nitric oxide and reactive oxygen intermediates, the stimulation of microbe intoxication mechanisms via acidification or metal accumulation in the phagolysosome, the restriction of the microbe's access to essential nutrients such as iron, fatty acids, or amino acids, the production of anti-microbial peptides and cytokines, along with induction of autophagy and efferocytosis to eliminate the pathogen. On the other hand, M. tuberculosis, as a prime example of a well-adapted facultative intracellular bacterium, has learned during evolution to counter-balance the host's immune defense strategies to secure survival or multiplication within this otherwise hostile environment. This review provides an overview of innate immune defense of macrophages directed against intracellular bacteria with a focus on M. tuberculosis. Gaining more insights and knowledge into this complex network of host-pathogen interaction will identify novel target sites of intervention to successfully clear infection at a time of rapidly emerging multi-resistance of M. tuberculosis against conventional antibiotics. © 2015 The Authors

  1. Macrophage defense mechanisms against intracellular bacteria

    Science.gov (United States)

    Weiss, Günter; Schaible, Ulrich E

    2015-01-01

    Macrophages and neutrophils play a decisive role in host responses to intracellular bacteria including the agent of tuberculosis (TB), Mycobacterium tuberculosis as they represent the forefront of innate immune defense against bacterial invaders. At the same time, these phagocytes are also primary targets of intracellular bacteria to be abused as host cells. Their efficacy to contain and eliminate intracellular M. tuberculosis decides whether a patient initially becomes infected or not. However, when the infection becomes chronic or even latent (as in the case of TB) despite development of specific immune activation, phagocytes have also important effector functions. Macrophages have evolved a myriad of defense strategies to combat infection with intracellular bacteria such as M. tuberculosis. These include induction of toxic anti-microbial effectors such as nitric oxide and reactive oxygen intermediates, the stimulation of microbe intoxication mechanisms via acidification or metal accumulation in the phagolysosome, the restriction of the microbe's access to essential nutrients such as iron, fatty acids, or amino acids, the production of anti-microbial peptides and cytokines, along with induction of autophagy and efferocytosis to eliminate the pathogen. On the other hand, M. tuberculosis, as a prime example of a well-adapted facultative intracellular bacterium, has learned during evolution to counter-balance the host's immune defense strategies to secure survival or multiplication within this otherwise hostile environment. This review provides an overview of innate immune defense of macrophages directed against intracellular bacteria with a focus on M. tuberculosis. Gaining more insights and knowledge into this complex network of host-pathogen interaction will identify novel target sites of intervention to successfully clear infection at a time of rapidly emerging multi-resistance of M. tuberculosis against conventional antibiotics. PMID:25703560

  2. Remediation of copper in vineyards--a mini review.

    Science.gov (United States)

    Mackie, K A; Müller, T; Kandeler, E

    2012-08-01

    Viticulturists use copper fungicide to combat Downy Mildew. Copper, a non-degradable heavy metal, can accumulate in soil or leach into water sources. Its accumulation in topsoil has impacted micro and macro organisms, spurring scientists to research in situ copper removal methods. Recent publications suggest that microorganism assisted phytoextraction, using plants and bacteria to actively extract copper, is most promising. As vineyards represent moderately polluted sites this technique has great potential. Active plant extraction and chelate assisted remediation extract too little copper or risk leaching, respectively. However, despite interesting pot experiment results using microorganism assisted phytoextraction, it remains a challenge to find plants that primarily accumulate copper in their shoots, a necessity in vineyards where whole plant removal would be time consuming and financially cumbersome. Vineyard remediation requires a holistic approach including sustainable soil management, proper plant selection, increasing biodiversity and microorganisms. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Intracellular Polyamines Enhance Astrocytic Coupling

    Science.gov (United States)

    Benedikt, Jan; Inyushin, Mikhail; Kucheryavykh, Yuriy V.; Rivera, Yomarie; Kucheryavykh, Lilia Y.; Nichols, Colin G.; Eaton, Misty J.; Skatchkov, Serguei N.

    2013-01-01

    Spermine (SPM) and spermidine (SPD), endogenous polyamines (PA) with the ability to modulate various ion channels and receptors in the brain, exert neuroprotective, antidepressant, antioxidant and other effects in vivo such as increasing longevity. These PA are preferably accumulated in astrocytes, and we hypothesized that SPM increases glial intercellular communication by interacting with glial gap junctions. Results obtained in situ, using Lucifer yellow propagation in the astrocytic syncitium of 21–25 day old rat CA1 hippocampal slices, showed reduced coupling when astrocytes were dialyzed with standard intracellular solutions (ICS) without SPM. However, there was a robust increase in the spreading of Lucifer yellow via gap junctions to neighboring astrocytes when the cells were patched with ICS containing 1 mM SPM; a physiological concentration in glia. Lucifer yellow propagation was inhibited by gap junction blockers. Our findings show that the glial syncitium propagates SPM via gap junctions and further suggest a new role of polyamines in the regulation of the astroglial network in both normal and pathological conditions. PMID:23076119

  4. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation

    Science.gov (United States)

    Liu, Ling-ling; Jia, Bo; Zhao, Fang; Huang, Wei-dong; Zhan, Ji-cheng

    2015-01-01

    At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China’s stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress. PMID:26030864

  5. Copper Tolerance and Biosorption of Saccharomyces cerevisiae during Alcoholic Fermentation.

    Science.gov (United States)

    Sun, Xiang-Yu; Zhao, Yu; Liu, Ling-Ling; Jia, Bo; Zhao, Fang; Huang, Wei-Dong; Zhan, Ji-Cheng

    2015-01-01

    At high levels, copper in grape mash can inhibit yeast activity and cause stuck fermentations. Wine yeast has limited tolerance of copper and can reduce copper levels in wine during fermentation. This study aimed to understand copper tolerance of wine yeast and establish the mechanism by which yeast decreases copper in the must during fermentation. Three strains of Saccharomyces cerevisiae (lab selected strain BH8 and industrial strains AWRI R2 and Freddo) and a simple model fermentation system containing 0 to 1.50 mM Cu2+ were used. ICP-AES determined Cu ion concentration in the must decreasing differently by strains and initial copper levels during fermentation. Fermentation performance was heavily inhibited under copper stress, paralleled a decrease in viable cell numbers. Strain BH8 showed higher copper-tolerance than strain AWRI R2 and higher adsorption than Freddo. Yeast cell surface depression and intracellular structure deformation after copper treatment were observed by scanning electron microscopy and transmission electron microscopy; electronic differential system detected higher surface Cu and no intracellular Cu on 1.50 mM copper treated yeast cells. It is most probably that surface adsorption dominated the biosorption process of Cu2+ for strain BH8, with saturation being accomplished in 24 h. This study demonstrated that Saccharomyces cerevisiae strain BH8 has good tolerance and adsorption of Cu, and reduces Cu2+ concentrations during fermentation in simple model system mainly through surface adsorption. The results indicate that the strain selected from China's stress-tolerant wine grape is copper tolerant and can reduce copper in must when fermenting in a copper rich simple model system, and provided information for studies on mechanisms of heavy metal stress.

  6. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

    Science.gov (United States)

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

  7. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

    Science.gov (United States)

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

  8. Use of flux analysis to study the compartmentation of copper in copper tolerant and non-tolerant Mimulus guttatus

    International Nuclear Information System (INIS)

    Shaw, P.; Collins, J.C.; Thurman, D.A.

    1987-01-01

    Compartmental flux analysis using 64 Cu and a stereological study have been used to estimate the amount and concentrations of copper in the cell wall, cytoplasm and vacuole of roots of non-tolerant and copper tolerant clones of Mimulus guttatus. The cell wall was not found to be a major site of copper accumulation in either clone compared with the cytoplasmic and vacuolar phases. The cytoplasmic concentrations of copper in the non-tolerant clone were significantly grater than those of the tolerant clone when grown in 2.0 and 10.0 μM external copper. At all external copper concentrations and for both clones vacuolar levels of copper were lower than the cytoplasmic ones. At 10.0 μM external copper the vacuolar concentrations of the non-tolerant clone were significantly higher than those of the tolerant clone

  9. Acumulación de cobre en una comunidad vegetal afectada por contaminación minera en el valle de Puchuncaví, Chile central Copper accumulation in a plant community affected by mining contamination in Puchuncaví valley, central Chile

    Directory of Open Access Journals (Sweden)

    ISABEL GONZÁLEZ

    2008-06-01

    Full Text Available Las especies hiperacumuladoras son capaces de acumular más de 1.000 mg kg-1 de metal en su biomasa aérea y son útiles en procesos de fitoextracción de metales en suelos contaminados por actividades mineras. Con el fin de identificar especies hiperacumuladoras representativas de las condiciones chilenas, se realizó una prospección dentro de la diversidad vegetal en el área afectada por las emisiones de la Fundición Ventanas (90-900 mg kg-1 de Cu total en suelos, así como en un área cercana a una pila de escorias de fundición (500-3.000 mg kg-1 de Cu total en suelos. Se determinaron las concentraciones de Cu en la biomasa aérea de las plantas. Los resultados indican que dentro de la diversidad del sitio existen al menos veintidós especies pseudometalofitas, es decir, ecotipos de especies comunes que son capaces de tolerar concentraciones de cobre en el suelo que para una planta normal serían tóxicas. Las especies fueron clasificadas según su concentración de cobre y mostraron en su mayoría media (200-600 mg kg-1 o baja (Hyperaccumulator plants species are capable of accumulating more than 1,000 mg Cu kg-1 in their shoots and are useful for metal phytoextraction in soils contaminated by mining activities. To identify the hyperaccumulator plants representative of the Chilean conditions, we carried out a survey of plant diversity in the área affected by the emissions of the Ventanas smelter (90-900 mg kg-1 of total Cu in soils and in a nearby área cióse to a smelter slug pile (500-3,000 mg kg-1 of total Cu in soils. Copper concentrations in the shoots of the studied plants were determined. Results indicate that there were at least twenty-two pseudometallophyte species, i.e., ecotypes of common species capable to tolérate concentrations of Cu in the soil that would be toxic for a normal plant. The species were classified by their copper accumulation and nearly all exhibited médium (200-600 mg kg-1 or low (< 200 mg kg-1

  10. Accumulate Repeat Accumulate Coded Modulation

    Science.gov (United States)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  11. Detection of ubiquitinated huntingtin species in intracellular aggregates

    NARCIS (Netherlands)

    Juenemann, Katrin; Wiemhoefer, Anne; Reits, Eric A.

    2015-01-01

    Protein conformation diseases, including polyglutamine (polyQ) diseases, result from the accumulation and aggregation of misfolded proteins. Huntington's disease (HD) is one of nine diseases caused by an expanded polyQ repeat within the affected protein and is hallmarked by intracellular inclusion

  12. Comparative effects of dissolved copper and copper oxide nanoparticle exposure to the sea anemone, Exaiptasia pallida

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Samreen; Goddard, Russell H.; Bielmyer-Fraser, Gretchen K., E-mail: gkbielmyer@valdosta.edu

    2015-03-15

    Highlights: • Differences between CuO NP and CuCl{sub 2} exposure were characterized. • Copper accumulation in E. pallida was concentration-dependent. • E. pallida exposed to CuCl{sub 2} accumulated higher copper tissue burdens. • The oxidative stress response was greater in E. pallida exposed to CuO NP. • Both forms of copper inhibited CA activity in E. pallida. - Abstract: Increasing use of metal oxide nanoparticles (NP) by various industries has resulted in substantial output of these NP into aquatic systems. At elevated concentrations, NP may interact with and potentially affect aquatic organisms. Environmental implications of increased NP use are largely unknown, particularly in marine systems. This research investigated and compared the effects of copper oxide (CuO) NP and dissolved copper, as copper chloride (CuCl{sub 2}), on the sea anemone, Exaiptasia pallida. Sea anemones were collected over 21 days and tissue copper accumulation and activities of the enzymes: catalase, glutathione peroxidase, glutathione reductase, and carbonic anhydrase were quantified. The size and shape of CuO NP were observed using a ecanning electron microscope (SEM) and the presence of copper was confirmed by using Oxford energy dispersive spectroscopy systems (EDS/EDX). E. pallida accumulated copper in their tissues in a concentration- and time-dependent manner, with the animals exposed to CuCl{sub 2} accumulating higher tissue copper burdens than those exposed to CuO NP. As a consequence of increased copper exposure, as CuO NP or CuCl{sub 2}, anemones increased activities of all of the antioxidant enzymes measured to some degree, and decreased the activity of carbonic anhydrase. Anemones exposed to CuO NP generally had higher anti-oxidant enzyme activities than those exposed to the same concentrations of CuCl{sub 2}. This study is useful in discerning differences between CuO NP and dissolved copper exposure and the findings have implications for exposure of aquatic

  13. Uptake and distribution of copper in the freshwater crab ...

    African Journals Online (AJOL)

    ... between the two localities. P. perlatus may therefore still be utilized in biomonitoring studies, not necessarily to reflect prevailing environmental concentrations, since copper can also be regulated, but to assess exposure to and bioavailibility of copper. Key words: heavy metal accumulation, digestive gland, biomonitoring.

  14. Characterization of copper resistant ciliates: Potential candidates for ...

    African Journals Online (AJOL)

    The ciliate protists tolerate elevated concentrations of metals, which are accumulated, bound to metallothioneins (MTs) peculiar to these organisms. Copper is one of such contaminant found in the wastewater of local industries. The concentrations of copper which caused 50% reduction (LC50) in the cell population of ...

  15. Remediation of copper in vineyards – A mini review

    International Nuclear Information System (INIS)

    Mackie, K.A.; Müller, T.; Kandeler, E.

    2012-01-01

    Viticulturists use copper fungicide to combat Downy Mildew. Copper, a non-degradable heavy metal, can accumulate in soil or leach into water sources. Its accumulation in topsoil has impacted micro and macro organisms, spurring scientists to research in situ copper removal methods. Recent publications suggest that microorganism assisted phytoextraction, using plants and bacteria to actively extract copper, is most promising. As vineyards represent moderately polluted sites this technique has great potential. Active plant extraction and chelate assisted remediation extract too little copper or risk leaching, respectively. However, despite interesting pot experiment results using microorganism assisted phytoextraction, it remains a challenge to find plants that primarily accumulate copper in their shoots, a necessity in vineyards where whole plant removal would be time consuming and financially cumbersome. Vineyard remediation requires a holistic approach including sustainable soil management, proper plant selection, increasing biodiversity and microorganisms. - Highlights: ► We describe copper distribution and availability in vineyards. ► We explain the environmental impact of copper on organisms, plants and processes. ► We detail possible remediation methods within vineyards. ► Microbially assisted phytoremediation is the most promising remediation method. ► A solution requires an interdisciplinary approach between plants, soil and vines. - This review is significant because it highlights prospective remediation methods usable in copper contaminated vineyards.

  16. Subcellular site and nature of intracellular cadmium in plants

    International Nuclear Information System (INIS)

    Wagner, G.J.

    1979-01-01

    The mechanisms underlying heavy metal accumulation, toxicity, and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent, subcellular site and nature of intracellularly accumulated cadmium in higher plants. Whole plants supplied 109 CdCl 2 or 112 CdSO 4 accumulated Cd into roots and aerial tissues. Preparation of protoplasts from aerial tissues followed by subcellular fractionation of the protoplasts to obtain intact vacuoles, chloroplasts and cytosol revealed the presence of Cd in the cytosol but not in vacuoles or chloroplasts. No evidence was obtained for the production of volatile Cd complexes in tobacco

  17. Transgenic Nicotiana tabacum plants expressing a fungal copper transporter gene show enhanced acquisition of copper.

    Science.gov (United States)

    Singh, Sudhir; Korripally, Premsagar; Vancheeswaran, Ramachandran; Eapen, Susan

    2011-10-01

    The diets of two-thirds of the world's population are deficient in one or more essential elements and one of the approaches to enhance the levels of mineral elements in food crops is by developing plants with ability to accumulate them in edible parts. Besides conventional methods, transgenic technology can be used for enhancing metal acquisition in plants. Copper is an essential element, which is often deficient in human diet. With the objective of developing plants with improved copper acquisition, a high-affinity copper transporter gene (tcu-1) was cloned from fungus Neurospora crassa and introduced into a model plant (Nicotiana tabacum). Integration of the transgene was confirmed by Southern blot hybridization. Transgenic tobacco plants (T(0) and T(1)) expressing tcu-1, when grown in hydroponic medium spiked with different concentrations of copper, showed higher acquisition of copper (up to 3.1 times) compared with control plants. Transgenic plants grown in soil spiked with copper could also take up more copper compared with wild-type plants. Supplementation of other divalent cations such as Cd(2+) and Zn(2+) did not alter uptake of Cu by transgenic plants. The present study has shown that expression of a heterologous copper transporter in tobacco could enhance acquisition of copper.

  18. Environmental concentrations of copper, chromium, and arsenic released from a chromated-copper-arsenate-(CCA-C-) treated wetland boardwalk

    Science.gov (United States)

    Stan T. Lebow; Daniel Foster

    2005-01-01

    A study was conducted to evaluate environmental accumulation and mobility of total copper, chromium, and arsenic adjacent to a chromated-copper-arsenate-(CCA-C-) treated wetland boardwalk. The study was considered a severe test because it included a large volume of treated wood in a site with high annual rainfall. Soil and sediment samples were collected before...

  19. Nutritional managment of inherited copper-associated hepatitis in the Labrador retriever.

    NARCIS (Netherlands)

    Fieten, Hille; Biourge, Vincent; Watson, AL; Leegwater, Peter; van den Ingh, T.S.G.A.M.; Rothuizen, J

    Canine hereditary copper-associated hepatitis is characterized by gradual hepatic copper accumulation eventually leading to liver cirrhosis. Therapy is aimed at creating a negative copper balance with metal chelators, of which d-penicillamine is the most commonly used. d-penicillamine often causes

  20. Separation of copper-64 from copper phthalocyanine

    International Nuclear Information System (INIS)

    Battaglin, R.I.M.

    1979-01-01

    The separation of copper-64 from irradiated copper phthalocyanine by Szilard-Chalmers effect is studied. Two methods of separation are used: one of them is based on the dissolution of the irradiated dry compound in concentrated sulfuric acid following its precipitation in water. In the other one the compound is irradiated with water in paste form following treatment with water and hydrochloric acid. The influence of the crystal form of the copper phthalocyanine on the separation yield of copper-64 is shown. Preliminary tests using the ionic exchange technique for purification and changing of copper-64 sulfate to chloride form are carried out. The specific activity using the spectrophotometric technique, after the determination of the copper concentration in solution of copper-64, is calculated. (Author) [pt

  1. Copper in plants

    OpenAIRE

    Yruela, Inmaculada

    2005-01-01

    Copper is an essential metal for normal plant growth and development, although it is also potentially toxic. Copper participates in numerous physiological processes and is an essential cofactor for many metalloproteins, however, problems arise when excess copper is present in cells. Excess copper inhibits plant growth and impairs important cellular processes (i.e., photosynthetic electron transport). Since copper is both an essential cofactor and a toxic element, involving a complex network o...

  2. Carbohydrate Reserves And Metal Accumulation Of The Nile Tilapia ...

    African Journals Online (AJOL)

    This study investigated the carbohydrate reserves and metal accumulation of the Nile tilapia, Oreochromis niloticus after exposure to sublethal concentrations of heavy metals such as copper, lead and zinc for a 12-week period, using static renewable toxicity tests. The concentrations of the metals accumulated in the tissue ...

  3. Microbial accumulation of uranium, radium, and cesium

    International Nuclear Information System (INIS)

    Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; North, S.E.

    1981-05-01

    Diverse microbial species varied considerably in their ability to accumulate uranium, cesium, and radium. Mechanistic differences in uranium uptake by Saccharomyces cerevisiae and Pseudomonas aeruginosa were indicated. S. serevisiae exhibited a slow (hours) surface accumulation of uranium which was subject to environmental factors, while P. aeruginosa accumulated uranium rapidly (minutes) as dense intracellular deposits and did not appear to be affected by environmental parameters. Metabolism was not required for uranium uptake by either organism. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several species tested

  4. The intracellular pharmacokinetics of terminally capped peptides.

    NARCIS (Netherlands)

    Ruttekolk, I.R.R.; Witsenburg, J.J.; Glauner, H.B.; Bovee-Geurts, P.H.M.; Ferro, E.S.; Verdurmen, W.P.R.; Brock, R.E.

    2012-01-01

    With significant progress in delivery technologies, peptides and peptidomimetics are receiving increasing attention as potential therapeutics also for intracellular applications. However, analyses of the intracellular behavior of peptides are a challenge; therefore, knowledge on the intracellular

  5. Photocytotoxic ternary copper(II) complexes of histamine Schiff base ...

    Indian Academy of Sciences (India)

    The photo-induced cell death is via generation of oxidative stress by reactive oxygen species. Keywords. Copper; dipyridophenazine ... apoptotic pathway involving photo-induced generation of intracellular reactive oxygen species ... Bruker Alpha and Perkin-Elmer Spectrum 650 spectro- photometers, respectively, at 25.

  6. Effect of copper on growth of an aquatic macrophyte, Elodea canadensis

    Energy Technology Data Exchange (ETDEWEB)

    Mal, T.K.; Adorjan, Peter; Corbett, A.L

    2002-12-01

    Elodea canadensis may be a good biomonitor for copper, but not a good bioaccumulator. - Elodea canadensis has been proposed as a potential biomonitor due to its wide distribution and apparent ability to accumulate pollutants in aquatic ecosystems. We investigated the effects of copper sulfate on growth in E. canadensis to determine its effectiveness as a biomonitor of copper pollution in aquatic systems and whether growth is a suitable index of sub-lethal stress. Copper sulfate significantly slowed or stopped growth at all concentrations (low: 1 ppm, medium: 5 ppm, high: 10 ppm of copper sulfate) used. Final plant drymass was significantly lower in medium and high copper treatments compared with controls. E. canadensis appears to be very sensitive to copper levels, and may be useful as a biomonitor of copper levels in aquatic systems. However, its utility as a bioaccumulator may be limited, because we observed senescence of most leaves in all copper-treated plants following 4 weeks of treatment.

  7. Effect of copper on growth of an aquatic macrophyte, Elodea canadensis

    International Nuclear Information System (INIS)

    Mal, T.K.; Adorjan, Peter; Corbett, A.L.

    2002-01-01

    Elodea canadensis may be a good biomonitor for copper, but not a good bioaccumulator. - Elodea canadensis has been proposed as a potential biomonitor due to its wide distribution and apparent ability to accumulate pollutants in aquatic ecosystems. We investigated the effects of copper sulfate on growth in E. canadensis to determine its effectiveness as a biomonitor of copper pollution in aquatic systems and whether growth is a suitable index of sub-lethal stress. Copper sulfate significantly slowed or stopped growth at all concentrations (low: 1 ppm, medium: 5 ppm, high: 10 ppm of copper sulfate) used. Final plant drymass was significantly lower in medium and high copper treatments compared with controls. E. canadensis appears to be very sensitive to copper levels, and may be useful as a biomonitor of copper levels in aquatic systems. However, its utility as a bioaccumulator may be limited, because we observed senescence of most leaves in all copper-treated plants following 4 weeks of treatment

  8. Visualizing Metal Content and Intracellular Distribution in Primary Hippocampal Neurons with Synchrotron X-Ray Fluorescence.

    Directory of Open Access Journals (Sweden)

    Robert A Colvin

    Full Text Available Increasing evidence suggests that metal dyshomeostasis plays an important role in human neurodegenerative diseases. Although distinctive metal distributions are described for mature hippocampus and cortex, much less is known about metal levels and intracellular distribution in individual hippocampal neuronal somata. To solve this problem, we conducted quantitative metal analyses utilizing synchrotron radiation X-Ray fluorescence on frozen hydrated primary cultured neurons derived from rat embryonic cortex (CTX and two regions of the hippocampus: dentate gyrus (DG and CA1. Comparing average metal contents showed that the most abundant metals were calcium, iron, and zinc, whereas metals such as copper and manganese were less than 10% of zinc. Average metal contents were generally similar when compared across neurons cultured from CTX, DG, and CA1, except for manganese that was larger in CA1. However, each metal showed a characteristic spatial distribution in individual neuronal somata. Zinc was uniformly distributed throughout the cytosol, with no evidence for the existence of previously identified zinc-enriched organelles, zincosomes. Calcium showed a peri-nuclear distribution consistent with accumulation in endoplasmic reticulum and/or mitochondria. Iron showed 2-3 distinct highly concentrated puncta only in peri-nuclear locations. Notwithstanding the small sample size, these analyses demonstrate that primary cultured neurons show characteristic metal signatures. The iron puncta probably represent iron-accumulating organelles, siderosomes. Thus, the metal distributions observed in mature brain structures are likely the result of both intrinsic neuronal factors that control cellular metal content and extrinsic factors related to the synaptic organization, function, and contacts formed and maintained in each region.

  9. Drosophila VAMP7 regulates Wingless intracellular trafficking.

    Science.gov (United States)

    Gao, Han; He, Fang; Lin, Xinhua; Wu, Yihui

    2017-01-01

    Drosophila Wingless (Wg) is a morphogen that determines cell fate during development. Previous studies have shown that endocytic pathways regulate Wg trafficking and signaling. Here, we showed that loss of vamp7, a gene required for vesicle fusion, dramatically increased Wg levels and decreased Wg signaling. Interestingly, we found that levels of Dally-like (Dlp), a glypican that can interact with Wg to suppress Wg signaling at the dorsoventral boundary of the Drosophila wing, were also increased in vamp7 mutant cells. Moreover, Wg puncta in Rab4-dependent recycling endosomes were Dlp positive. We hypothesize that VAMP7 is required for Wg intracellular trafficking and the accumulation of Wg in Rab4-dependent recycling endosomes might affect Wg signaling.

  10. Influence of intracellular Na + , K + and Cl - on the salt tolerance in ...

    African Journals Online (AJOL)

    In the process of selection for salt tolerance, it is important to understand the physiological basis of ion management executed by the cells through the exclusion, accumulation or maintenance of ratios of specific ions. Intracellular accumulation of Na+, K+ and Cl- ions in the cells in vitro was studied as a factor in salt ...

  11. Aquatic Life Criteria - Copper

    Science.gov (United States)

    Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2007 Freshwater, 2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

  12. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    1999-01-01

    In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

  13. Temporal aspects of copper homeostasis and its crosstalk with hormones

    Directory of Open Access Journals (Sweden)

    Lola ePeñarrubia

    2015-04-01

    Full Text Available To cope with the dual nature of copper as being essential and toxic for cells, plants temporarily adapt the expression of copper homeostasis components to assure its delivery to cuproproteins while avoiding the interference of potential oxidative damage derived from both copper uptake and photosynthetic reactions during light hours. The circadian clock participates in the temporal organization of coordination of plant nutrition adapting metabolic responses to the daily oscillations. This timely control improves plant fitness and reproduction and holds biotechnological potential to drive increased crop yields. Hormonal pathways, including those of abscisic acid, gibberellins, ethylene, auxins, and jasmonates are also under direct clock and light control, both in mono and dicotyledons. In this review, we focus on copper transport in Arabidopsis thaliana and Oryza sativa and the presumable role of hormones in metal homeostasis matching nutrient availability to growth requirements and preventing metal toxicity. The presence of putative hormone-dependent regulatory elements in the promoters of copper transporters genes suggests hormonal regulation to match special copper requirements during plant development. Spatial and temporal processes that can be affected by hormones include the regulation of copper uptake into roots, intracellular trafficking and compartmentalisation, and long-distance transport to developing vegetative and reproductive tissues. In turn, hormone biosynthesis and signalling are also influenced by copper availability, which suggests reciprocal regulation subjected to temporal control by the central oscillator of the circadian clock. This transcriptional regulatory network, coordinates environmental and hormonal signalling with developmental pathways to allow enhanced micronutrient acquisition efficiency.

  14. Biochemical characterization of the human copper transporter Ctr1.

    Science.gov (United States)

    Lee, Jaekwon; Peña, Maria Marjorette O; Nose, Yasuhiro; Thiele, Dennis J

    2002-02-08

    The trace metal copper is an essential cofactor for a number of biological processes including mitochondrial oxidative phosphorylation, free radical detoxification, neurotransmitter synthesis and maturation, and iron metabolism. Consequently, copper transport at the cell surface and the delivery of copper to intracellular proteins are critical events in normal physiology. Little is known about the molecules and biochemical mechanisms responsible for copper uptake at the plasma membrane in mammals. Here, we demonstrate that human Ctr1 (hCtr1) is a component of the copper transport machinery at the plasma membrane. hCtr1 transports copper with high affinity in a time-dependent and saturable manner and is metal-specific. hCtr1-mediated (64)Cu transport is an energy-independent process and is stimulated by extracellular acidic pH and high K(+) concentrations. hCtr1 exists as a homomultimer at the plasma membrane in mammalian cells. This is the first report on the biochemical characterization of the human copper transporter hCtr1, which is important for understanding mechanisms for mammalian copper transport at the plasma membrane.

  15. Demystifying Controlling Copper Corrosion

    Science.gov (United States)

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  16. A copper-induced quinone degradation pathway provides protection against combined copper/quinone stress in Lactococcus lactis IL1403.

    Science.gov (United States)

    Mancini, Stefano; Abicht, Helge K; Gonskikh, Yulia; Solioz, Marc

    2015-02-01

    Quinones are ubiquitous in the environment. They occur naturally but are also in widespread use in human and industrial activities. Quinones alone are relatively benign to bacteria, but in combination with copper, they become toxic by a mechanism that leads to intracellular thiol depletion. Here, it was shown that the yahCD-yaiAB operon of Lactococcus lactis IL1403 provides resistance to combined copper/quinone stress. The operon is under the control of CopR, which also regulates expression of the copRZA copper resistance operon as well as other L. lactis genes. Expression of the yahCD-yaiAB operon is induced by copper but not by quinones. Two of the proteins encoded by the operon appear to play key roles in alleviating quinone/copper stress: YaiB is a flavoprotein that converts p-benzoquinones to less toxic hydroquinones, using reduced nicotinamide adenine dinucleotide phosphate (NADPH) as reductant; YaiA is a hydroquinone dioxygenase that converts hydroquinone putatively to 4-hydroxymuconic semialdehyde in an oxygen-consuming reaction. Hydroquinone and methylhydroquinone are both substrates of YaiA. Deletion of yaiB causes increased sensitivity of L. lactis to quinones and complete growth arrest under combined quinone and copper stress. Copper induction of the yahCD-yaiAB operon offers protection to copper/quinone toxicity and could provide a growth advantage to L. lactis in some environments. © 2014 John Wiley & Sons Ltd.

  17. COPPER RESISTANT STRAIN CANDIDA TROPICALIS RomCu5 INTERACTION WITH SOLUBLE AND INSOLUBLE COPPER COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Ie. P. Prekrasna

    2015-10-01

    Full Text Available The focus of the study was interaction of Candida tropicalis RomCu5 isolated from highland Ecuador ecosystem with soluble and insoluble copper compounds. Strain C. tropicalis RomCu5 was cultured in a liquid medium of Hiss in the presence of soluble (copper citrate and CuCl2 and insoluble (CuO and CuCO3 copper compounds. The biomass growth was determined by change in optical density of culture liquid, composition of the gas phase was measured on gas chromatograph, redox potential and pH of the culture fluid was defined potentiometrically. The concentration of soluble copper compounds was determined colorimetrically. Maximal permissible concentration of Cu2+ for C. tropicalis RomCu5 was 30 000 ppm of Cu2+ in form of copper citrate and 500 ppm of Cu2+ in form of CuCl2. C. tropicalis was metabolically active at super high concentrations of Cu2+, despite the inhibitory effect of Cu2+. C. tropicalis immobilized Cu2+ in the form of copper citrate and CuCl2 by it accumulation in the biomass. Due to medium acidification C. tropicalis dissolved CuO and CuCO3. High resistance of C. tropicalis to Cu2+ and ability to interact with soluble and insoluble copper compounds makes it biotechnologically perspective.

  18. Leach-SX-EW copper revalorization from overburden of abandoned copper mine Cerovo, Eastern Serbia

    Directory of Open Access Journals (Sweden)

    Stevanović Z.

    2009-01-01

    Full Text Available Hydrometallurgical processes for copper revalorization from overburden of abandoned mine Cerovo in Eastern Serbia were studied. Paper contain results of percolation leaching tests, performed with acidic mine waters accumulated in the bottom of the former open pit, followed by solvent extraction (SX and electrowinning (EW processes on achieved copper pregnant leach solutions. Usage of accumulated waste waters was objected to minimizing the environmental hazard due to uncontrolled leaking of these waters in nearby creeks and rivers. Chemical composition of acidic mine waters used for leaching tests was: (g/dm3: Cu - 0.201; Fe - 0.095; Mn - 0.041; Zn - 0.026; Ni - 0.0004; pH value - 3.3. Copper content in overburden sample used for leaching tests was 0.21% from which 64% were oxide copper minerals. In scope of leaching tests were examined influence of leaching solution pH values and iron (III concentration on copper recovery. It was established that for 120 hours of leaching on pH=1.5 without oxidant agents, copper concentration in pregnant leach solutions enriched up to 1.08g/dm3 which was enough for copper extraction from solution with SX-EW treatment. As extraction reagent in SX circuit was used LIX-984N in a kerosene diluent. Cathode current density in electrowinning cell was 220Am-2 while electrolyte temperature was kept on 50±2oC. Produced cathode copper at the end of SX-EW process has purity of 99.95% Cu.

  19. Stochastic cooling and the accumulation of antiprotons

    CERN Document Server

    van der Meer, S

    1985-01-01

    The large project mentioned in the motivation of the 1985 Nobel award in physics includes, in addition to the experiments proper described by Carlo Rubbia, the complex machinery for colliding high-energy protons and antiprotons. Protons (ps) are accelerated to a momentum of 26 GeV/c in the Proton Synchrotron (PS) machine and are used to produce antiprotons (ps) in a copper target. The Antiproton Accumulator (AA) ring accepts a batch of these with momenta around 3.5 GeV/c every 2.4 seconds. After, typically, a day of accumulation, a large number of the accumulated ps ( approximately 10/sup 11/) are extracted from the AA. The author discusses stochastic cooling, a method used to accumulate the antiprotons. (23 refs).

  20. Effect of copper on growth of an aquatic macrophyte, Elodea canadensis.

    Science.gov (United States)

    Mal, Tarun K; Adorjan, Peter; Corbett, Andrea L

    2002-01-01

    Elodea canadensis has been proposed as a potential biomonitor due to its wide distribution and apparent ability to accumulate pollutants in aquatic ecosystems. We investigated the effects of copper sulfate on growth in E. canadensis to determine its effectiveness as a biomonitor of copper pollution in aquatic systems and whether growth is a suitable index of sub-lethal stress. Copper sulfate significantly slowed or stopped growth at all concentrations (low: 1 ppm, medium: 5 ppm, high: 10 ppm of copper sulfate) used. Final plant drymass was significantly lower in medium and high copper treatments compared with controls. E. canadensis appears to be very sensitive to copper levels, and may be useful as a biomonitor of copper levels in aquatic systems. However, its utility as a bioaccumulator may be limited, because we observed senescence of most leaves in all copper-treated plants following 4 weeks of treatment.

  1. REMOVAL OF COPPER ELECTROLYTE CONTAMINANTS BY ADSORPTION

    Directory of Open Access Journals (Sweden)

    B Gabai

    1997-09-01

    Full Text Available Abstract - Selective adsorbents have become frequently used in industrial processes. Recent studies have shown the possibility of using adsorption to separate copper refinery electrolyte contaminants, with better results than those obtained with conventional techniques. During copper electrorefinning, many impurities may be found as dissolved metals present in the anode slime which forms on the electrode surface, accumulated in the electrolyte or incorporated into the refined copper on the cathode by deposition. In this study, synthetic zeolites, chelating resins and activated carbons were tested as adsorbents to select the best adsorbent performance, as well as the best operating temperature for the process. The experimental method applied was the finite bath, which consists in bringing the adsorbent into contact with a finite volume of electrolyte while controlling the temperature. The concentration of metals in the liquid phase was continuously monitored by atomic absorption spectrophotometry (AAS

  2. Mechanisms underlying reductant-induced reactive oxygen species formation by anticancer copper(II) compounds.

    Science.gov (United States)

    Kowol, Christian R; Heffeter, Petra; Miklos, Walter; Gille, Lars; Trondl, Robert; Cappellacci, Loredana; Berger, Walter; Keppler, Bernhard K

    2012-03-01

    Intracellular generation of reactive oxygen species (ROS) via thiol-mediated reduction of copper(II) to copper(I) has been assumed as the major mechanism underlying the anticancer activity of copper(II) complexes. The aim of this study was to compare the anticancer potential of copper(II) complexes of Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone; currently in phase II clinical trials) and its terminally dimethylated derivative with that of 2-formylpyridine thiosemicarbazone and that of 2,2'-bipyridyl-6-carbothioamide. Experiments on generation of oxidative stress and the influence of biologically relevant reductants (glutathione, ascorbic acid) on the anticancer activity of the copper complexes revealed that reductant-dependent redox cycling occurred mainly outside the cells, leading to generation and dismutation of superoxide radicals resulting in cytotoxic amounts of H(2)O(2). However, without extracellular reductants only weak intracellular ROS generation was observed at IC(50) levels, suggesting that cellular thiols are not involved in copper-complex-induced oxidative stress. Taken together, thiol-induced intracellular ROS generation might contribute to the anticancer activity of copper thiosemicarbazone complexes but is not the determining factor.

  3. Tolerance and bioaccumulation of copper by the entomopathogen Beauveria bassiana (Bals.-Criv.) Vuill. exposed to various copper-based fungicides.

    Science.gov (United States)

    Martins, Fátima; Soares, Maria Elisa; Oliveira, Ivo; Pereira, José Alberto; de Lourdes Bastos, Maria; Baptista, Paula

    2012-07-01

    This work evaluates for the first time the relationships between copper-tolerance, -solubilization and -bioaccumulation in the entomopathogen Beauveria bassiana exposed to Bordeaux mixture, copper oxychloride or copper hydroxide. Bordeaux mixture was highly detrimental to fungus, by inhibiting the growth totally at the recommended dose (RD) and 2×RD. Copper hydroxide and copper oxychloride were found to be less toxic, reducing fungus growth, sporulation and conidial germination in an average of 29  %, 30 % and 58 %, respectively. These two copper forms were the easiest to solubilize, to precipitate and the most accumulated by B. bassiana, suggesting the involvement of all these processes on fungus copper-tolerance.

  4. Activation of chick tendon lysyl oxidase in response to dietary copper.

    Science.gov (United States)

    Rucker, R B; Rucker, B R; Mitchell, A E; Cui, C T; Clegg, M; Kosonen, T; Uriu-Adams, J Y; Tchaparian, E H; Fishman, M; Keen, C L

    1999-12-01

    Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in connective tissue. Herein, we assess the extent to which tissue copper concentrations and lysyl oxidase activity are related because the functional activity of lysyl oxidase and the copper content of chick tendon are both related to dietary copper intake. Chicks (1-d old) were fed diets (basal copper concentration, 0.4 microg/g diet) to which copper was added from 0 to 16 microg/g diet. Liver and plasma copper levels tended to normalize in chickens that consumed from 1 to 4 microg copper/g of diet, whereas tendon copper concentrations suggested an unusual accumulation of copper in chickens that consumed 16 microg copper/g diet. The molecular weight of lysyl oxidase was also estimated using matrix-assisted laser desorption ionization/time-of-flight/mass spectrometry (MALDI/TOF/MS). A novel aspect of these measurements was estimation of protein mass directly from the surface of chick tendons and aortae. Whether copper deficiency (0 added copper) or copper supplementation (16 microg copper/g of diet) caused changes in the molecular weight of protein(s) in tendon corresponding to lysyl oxidase was addressed. The average molecular weight of the peak corresponding to lysyl oxidase in tendon and aorta from copper-deficient birds was 28,386 Da +/- 86, whereas the average molecular weight of corresponding protein in tendon from copper-supplemented birds was 28,639 Da +/- 122. We propose that the shift in molecular weight is due in part to copper binding and the formation of lysyl tyrosyl quinone, the cofactor at the active site of lysyl oxidase.

  5. Subcellular site and nature of intracellular cadmium in plants

    International Nuclear Information System (INIS)

    Wagner, G.J.

    1979-01-01

    The mechanisms underlying heavy metal accumulation, toxicity and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent of, subcellular site of and nature of intracellularly accumulated cadmium in higher plants. Whole plants supplied 109 CdCl 2 or 112 CdSO 4 accumulated Cd into roots and aerial tissues. Preparation of protoplasts from aerial tissue followed by subcellular fractionation of the protoplasts to obtain intact vacuoles, chloroplasts and cytosol revealed the presence of Cd in the cytosol but not in vacuoles or chloroplasts. Particulate materials containing other cell components were also labeled. Of the 109 Cd supplied to plants, 2 to 10% was recovered in both cytosol preparations and in particulate materials. Cytosol contained proteinaceous--Cd complexes, free metal and low molecular weight Cd complexes. Labeling of protoplasts gave similar results. No evidence was obtained for the production of volatile Cd complexes in tobacco

  6. The Menkes and Wilson disease genes counteract in copper toxicosis in Labrador retrievers: a new canine model for copper-metabolism disorders

    Science.gov (United States)

    Fieten, Hille; Gill, Yadvinder; Martin, Alan J.; Concilli, Mafalda; Dirksen, Karen; van Steenbeek, Frank G.; Spee, Bart; van den Ingh, Ted S. G. A. M.; Martens, Ellen C. C. P.; Festa, Paola; Chesi, Giancarlo; van de Sluis, Bart; Houwen, Roderick H. J. H.; Watson, Adrian L.; Aulchenko, Yurii S.; Hodgkinson, Victoria L.; Zhu, Sha; Petris, Michael J.; Polishchuk, Roman S.; Leegwater, Peter A. J.; Rothuizen, Jan

    2016-01-01

    ABSTRACT The deleterious effects of a disrupted copper metabolism are illustrated by hereditary diseases caused by mutations in the genes coding for the copper transporters ATP7A and ATP7B. Menkes disease, involving ATP7A, is a fatal neurodegenerative disorder of copper deficiency. Mutations in ATP7B lead to Wilson disease, which is characterized by a predominantly hepatic copper accumulation. The low incidence and the phenotypic variability of human copper toxicosis hamper identification of causal genes or modifier genes involved in the disease pathogenesis. The Labrador retriever was recently characterized as a new canine model for copper toxicosis. Purebred dogs have reduced genetic variability, which facilitates identification of genes involved in complex heritable traits that might influence phenotype in both humans and dogs. We performed a genome-wide association study in 235 Labrador retrievers and identified two chromosome regions containing ATP7A and ATP7B that were associated with variation in hepatic copper levels. DNA sequence analysis identified missense mutations in each gene. The amino acid substitution ATP7B:p.Arg1453Gln was associated with copper accumulation, whereas the amino acid substitution ATP7A:p.Thr327Ile partly protected against copper accumulation. Confocal microscopy indicated that aberrant copper metabolism upon expression of the ATP7B variant occurred because of mis-localization of the protein in the endoplasmic reticulum. Dermal fibroblasts derived from ATP7A:p.Thr327Ile dogs showed copper accumulation and delayed excretion. We identified the Labrador retriever as the first natural, non-rodent model for ATP7B-associated copper toxicosis. Attenuation of copper accumulation by the ATP7A mutation sheds an interesting light on the interplay of copper transporters in body copper homeostasis and warrants a thorough investigation of ATP7A as a modifier gene in copper-metabolism disorders. The identification of two new functional variants in

  7. The Menkes and Wilson disease genes counteract in copper toxicosis in Labrador retrievers: a new canine model for copper-metabolism disorders

    Directory of Open Access Journals (Sweden)

    Hille Fieten

    2016-01-01

    Full Text Available The deleterious effects of a disrupted copper metabolism are illustrated by hereditary diseases caused by mutations in the genes coding for the copper transporters ATP7A and ATP7B. Menkes disease, involving ATP7A, is a fatal neurodegenerative disorder of copper deficiency. Mutations in ATP7B lead to Wilson disease, which is characterized by a predominantly hepatic copper accumulation. The low incidence and the phenotypic variability of human copper toxicosis hamper identification of causal genes or modifier genes involved in the disease pathogenesis. The Labrador retriever was recently characterized as a new canine model for copper toxicosis. Purebred dogs have reduced genetic variability, which facilitates identification of genes involved in complex heritable traits that might influence phenotype in both humans and dogs. We performed a genome-wide association study in 235 Labrador retrievers and identified two chromosome regions containing ATP7A and ATP7B that were associated with variation in hepatic copper levels. DNA sequence analysis identified missense mutations in each gene. The amino acid substitution ATP7B:p.Arg1453Gln was associated with copper accumulation, whereas the amino acid substitution ATP7A:p.Thr327Ile partly protected against copper accumulation. Confocal microscopy indicated that aberrant copper metabolism upon expression of the ATP7B variant occurred because of mis-localization of the protein in the endoplasmic reticulum. Dermal fibroblasts derived from ATP7A:p.Thr327Ile dogs showed copper accumulation and delayed excretion. We identified the Labrador retriever as the first natural, non-rodent model for ATP7B-associated copper toxicosis. Attenuation of copper accumulation by the ATP7A mutation sheds an interesting light on the interplay of copper transporters in body copper homeostasis and warrants a thorough investigation of ATP7A as a modifier gene in copper-metabolism disorders. The identification of two new functional

  8. Copper in the sea: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.L.

    1977-04-01

    Life in the sea is vulnerable to the influx of trace metals resulting from man's activities. Although many pollutants introduced to the sea eventually degrade to less harmful forms, trace metals accumulate in sediments and have a continued potential for effect on biota. Copper has a toxic potential exceeding all other metals due to the quantity discharged and its toxicological effect. Fortunately, copper in the oceans is rendered less bioavailable or less toxic by its ready interaction with the complex chemical components of seawater. This bibliography was prepared to illustrate the status of current knowledge of the biogeochemistry of copper and to aid the development of research programs to define the effects of copper discharged to the marine environment. The references are categorized to aid the reader to locate literature concerning specific aspects of the biogeochemistry of copper. A brief comment describing the important findings in each category is given. Although this bibliography is not exhaustive, the listed references are likely representative of current knowledge.

  9. Stochastic models of intracellular transport

    KAUST Repository

    Bressloff, Paul C.

    2013-01-09

    The interior of a living cell is a crowded, heterogenuous, fluctuating environment. Hence, a major challenge in modeling intracellular transport is to analyze stochastic processes within complex environments. Broadly speaking, there are two basic mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually in the form of adenosine triphosphate hydrolysis, and can be direction specific, allowing biomolecules to be transported long distances; this is particularly important in neurons due to their complex geometry. In this review a wide range of analytical methods and models of intracellular transport is presented. In the case of diffusive transport, narrow escape problems, diffusion to a small target, confined and single-file diffusion, homogenization theory, and fractional diffusion are considered. In the case of active transport, Brownian ratchets, random walk models, exclusion processes, random intermittent search processes, quasi-steady-state reduction methods, and mean-field approximations are considered. Applications include receptor trafficking, axonal transport, membrane diffusion, nuclear transport, protein-DNA interactions, virus trafficking, and the self-organization of subcellular structures. © 2013 American Physical Society.

  10. Transfer and accumulation of lead, zinc, cadmium and copper in ...

    African Journals Online (AJOL)

    TUOYO

    roots (TF < 1); whereas for barley, metals are fairly distributed between the roots and the outer part (TF ≈. 1). These results suggest that the cultivated areas inside the mining district constitute a serious source of contamination of the food chain. Therefore, actions have to be taken in order to remedy this problem. Key words: ...

  11. Cupriavidus pinatubonensis AEO106 deals with copper-induced oxidative stress before engaging in biodegradation of the herbicide 4-chloro-2-methylphenoxyacetic acid

    DEFF Research Database (Denmark)

    Svenningsen, Nanna Bygvraa; Damgaard, Mette; Rasmussen, Maria Katrine

    2017-01-01

    BACKGROUND: Microbial degradation of phenoxy acid (PA) herbicides in agricultural soils is important to minimize herbicide leaching to groundwater reservoirs. Degradation may, however, be hampered by exposure of the degrader bacteria to toxic metals as copper (Cu) in the soil environment. Exposure...... to Cu leads to accumulation of intracellular reactive oxygen species (ROS) in some bacteria, but it is not known how Cu-derived ROS and an ensuing oxidative stress affect the degradation of PA herbicides. Based on the previously proposed paradigm that bacteria deal with environmental stress before...... they engage in biodegradation, we studied how the degradation of the PA herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) by the model PA degrader Cupriavidus pinatubonensis AEO106 was affected by Cu exposure. RESULTS: Exposure of C. pinatubonensis in batch culture to sublethal concentrations of Cu...

  12. Copper is a potent inhibitor of both the canonical and non-canonical NFκB pathways

    Science.gov (United States)

    Kenneth, Niall S; Hucks, Jr, George E; Kocab, Andrew J; McCollom, Annie L; Duckett, Colin S

    2014-01-01

    Copper is an essential trace element that plays key roles in many metabolic processes. Homeostatic regulation of intracellular copper is normally tightly controlled, but deregulated copper levels are found in numerous metabolic and neurodegenerative diseases, as well as in a range of neoplasms. There are conflicting reports regarding the exact role of copper in the regulation of NFκB-responsive genes, specifically whether copper leads to increased activation of the NFκB pathways, or downregulation. Here we show that increased intracellular levels of copper, using the ionophore clioquinol, leads to a potent inhibition of NFκB pathways, induced by multiple distinct stimuli. Addition of copper to cells inhibits ubiquitin-mediated degradation of IκBα by preventing its phoshorylation by the upstream IKK complex. Intriguingly, copper-dependent inhibition of NFκB can be reversed by the addition of the reducing agent, N-acetylcysteine (NAC). These results suggest that the oxidative properties of excess copper prevent NFκB activation by blocking IκBα destruction, and that NFκB activity should be assessed in diseases associated with copper excess. PMID:24552822

  13. The Necessity of Having a Tetradentate Ligand to Extract Copper(II) Ions from Amyloids

    OpenAIRE

    Nguyen, Michel; Rechignat, Lionel; Robert, Anne; Meunier, Bernard

    2014-01-01

    The accumulation of redox-active metal ions, in particular copper, in amyloid plaques is considered to the cause of the intensive oxidation damage to the brain of patients with Alzheimers disease (AD). Drug candidates based on a bis(8-aminoquinoline) tetradentate ligand are able to efficiently extract Cu2+ from copper-loaded amyloids (Cu?A?). Contrarily, in the presence of a bidentate hydroxyquinoline, such as clioquinol, the copper is not released from A?, but remains sequestrated within a A...

  14. Acúmulo e formas de cobre e zinco no solo após aplicações sucessivas de dejeto líquido de suínos Copper and zinc forms and accumulation in soil after successive pig slurry applications

    Directory of Open Access Journals (Sweden)

    Eduardo Girotto

    2010-06-01

    Full Text Available As aplicações sucessivas de dejeto líquido de suínos no solo podem aumentar os teores e alterar as formas de Cu e Zn no solo. O presente trabalho teve como objetivo estimar o acúmulo de Cu e Zn e suas formas em solo submetido a aplicações sucessivas de dejeto líquido de suínos, em sistema plantio direto com rotação de culturas. O trabalho foi desenvolvido em um Argissolo Vermelho distrófico arênico na área experimental do Departamento de Engenharia Agrícola da Universidade Federal de Santa Maria (RS. Os tratamentos consistiram na aplicação de 0, 20, 40 e 80 m³ ha-1 de dejeto líquido de suínos. Foram realizadas 17 aplicações de dejetos de maio de 2000 até o momento da coleta do solo, em outubro de 2006. Amostras de solo foram coletadas nas camadas de 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60 cm, secas ao ar, passadas em peneiras de 2 mm e moídas em grau de ágata. Em seguida, foram preparadas e analisados os teores pseudototais após extração pelo método 3050B da EPA, disponíveis por meio da extração com HCl 0,1 mol L-1, além do fracionamento químico do Cu e do Zn. Nos dejetos de suínos foram determinados os teores pseudototais de Cu e Zn. As aplicações sucessivas de dejeto líquido de suínos no solo aumentaram os teores de Cu e Zn das camadas superficiais, com migração até 12 e 10 cm de profundidade, respectivamente. O Cu e Zn adicionados são acumulados no solo em formas biodisponíveis, sendo preferencialmente ligados às frações orgânica e mineral, respectivamente.Successive applications of pig slurry in the soil can increase the levels and change the forms of copper (Cu and zinc (Zn. The objective of this study was to evaluate Cu and Zn accumulation and forms in the soil of areas with successive pig slurry applications under no tillage crop rotation. The experiment was carried out in a Typic Hapludalf in the experimental area of the

  15. Intracellular sphingosine releases calcium from lysosomes

    Science.gov (United States)

    Höglinger, Doris; Haberkant, Per; Aguilera-Romero, Auxiliadora; Riezman, Howard; Porter, Forbes D; Platt, Frances M; Galione, Antony; Schultz, Carsten

    2015-01-01

    To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC. DOI: http://dx.doi.org/10.7554/eLife.10616.001 PMID:26613410

  16. Intracellular ion channels and cancer

    Directory of Open Access Journals (Sweden)

    Luigi eLeanza

    2013-09-01

    Full Text Available Several types of channels play a role in the maintenance of ion homeostasis in subcellular organelles including endoplasmatic reticulum, nucleus, lysosome, endosome and mitochondria. Here we give a brief overview of the contribution of various mitochondrial and other organellar channels to cancer cell proliferation or death. Much attention is focused on channels involved in intracellular calcium signaling and on ion fluxes in the ATP-producing organelle mitochondria. Mitochondrial K+ channels (Ca2+-dependent BKCa and IKCa, ATP-dependent KATP, Kv1.3, two-pore TWIK-related Acid-Sensitive K+ channel-3 (TASK-3, Ca2+ uniporter MCU, Mg2+-permeable Mrs2, anion channels (voltage-dependent chloride channel VDAC, intracellular chloride channel CLIC and the Permeability Transition Pore (MPTP contribute importantly to the regulation of function in this organelle. Since mitochondria play a central role in apoptosis, modulation of their ion channels by pharmacological means may lead to death of cancer cells. The nuclear potassium channel Kv10.1 and the nuclear chloride channel CLIC4 as well as the endoplasmatic reticulum (ER-located inositol 1,4,5-trisphosphate (IP3 receptor, the ER-located Ca2+ depletion sensor STIM1 (stromal interaction molecule 1, a component of the store-operated Ca2+ channel and the ER-resident TRPM8 are also mentioned. Furthermore, pharmacological tools affecting organellar channels and modulating cancer cell survival are discussed. The channels described in this review are summarized on Figure 1. Overall, the view is emerging that intracellular ion channels may represent a promising target for cancer treatment.

  17. Copper and silver halates

    CERN Document Server

    Woolley, EM; Salomon, M

    2013-01-01

    Copper and Silver Halates is the third in a series of four volumes on inorganic metal halates. This volume presents critical evaluations and compilations for halate solubilities of the Group II metals. The solubility data included in this volume are those for the five compounds, copper chlorate and iodate, and silver chlorate, bromate and iodate.

  18. Tempol Normalizes Aortic Relaxation But Not Elevated Isoprostanes or PGE2 in Copper-Deficient Rats

    Science.gov (United States)

    Copper deficiency promotes accumulation of reactive oxygen species, which likely impair nitric oxide mediated relaxation as well as trigger vascular inflammation. We hypothesize that an antioxidant supplementation would diminish oxidative stress, restore aortic relaxation, and limit pro-inflammatory...

  19. Rapid lupus autoantigen relocalization and reactive oxygen species accumulation following ultraviolet irradiation of human keratinocytes.

    NARCIS (Netherlands)

    Lawley, W.; Doherty, A; Denniss, S; Chauhan, D; Pruijn, G.J.M.; Venrooij, W.J.W. van; Lunec, J; Herbert, K

    2000-01-01

    OBJECTIVE: In vitro treatment with ultraviolet B (UVB) induces relocalization of lupus autoantigens to the cell surface. We have addressed the relationship between autoantigen relocalization, accumulation of intracellular reactive oxygen species (ROS) and the induction of apoptosis following UVA and

  20. Accumulation of hepatic Hsp70 and plasma cortisol in Oreochromis ...

    African Journals Online (AJOL)

    The hepatic isoforms Hsp70, Hsp74 and Hsp76 were identified and quantified from copper exposures. Long-term DDT exposure did not result in significant induction of hepatic Hsp70. An increase in plasma cortisol concentration was associated with a decrease in heat shock protein accumulation after cadmium exposure, ...

  1. Copper homeostasis in Mycobacterium tuberculosis.

    Science.gov (United States)

    Shi, Xiaoshan; Darwin, K Heran

    2015-06-01

    Copper (Cu) is a trace element essential for the growth and development of almost all organisms, including bacteria. However, Cu overload in most systems is toxic. Studies show Cu accumulates in macrophage phagosomes infected with bacteria, suggesting Cu provides an innate immune mechanism to combat invading pathogens. To counteract the host-supplied Cu, increasing evidence suggests that bacteria have evolved Cu resistance mechanisms to facilitate their pathogenesis. In particular, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, has evolved multiple pathways to respond to Cu. Here, we summarize what is currently known about Cu homeostasis in Mtb and discuss potential sources of Cu encountered by this and other pathogens in a mammalian host.

  2. Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

    Science.gov (United States)

    Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...

  3. The CTR/COPT-dependent copper uptake and SPL7-dependent copper deficiency responses are required for basal cadmium tolerance in A. thaliana

    Science.gov (United States)

    Copper (Cu) homeostasis in plants is maintained by at least two mechanisms: 1) the miRNA-dependent reallocation of intracellular Cu among major Cu-enzymes and important energy-related functions; 2) the regulation of the expression of Cu transporters including members of the CTR/COPT family. These ev...

  4. Aspergillus fumigatus Copper Export Machinery and Reactive Oxygen Intermediate Defense Counter Host Copper-Mediated Oxidative Antimicrobial Offense

    Directory of Open Access Journals (Sweden)

    Philipp Wiemann

    2017-05-01

    Full Text Available The Fenton-chemistry-generating properties of copper ions are considered a potent phagolysosome defense against pathogenic microbes, yet our understanding of underlying host/microbe dynamics remains unclear. We address this issue in invasive aspergillosis and demonstrate that host and fungal responses inextricably connect copper and reactive oxygen intermediate (ROI mechanisms. Loss of the copper-binding transcription factor AceA yields an Aspergillus fumigatus strain displaying increased sensitivity to copper and ROI in vitro, increased intracellular copper concentrations, decreased survival in challenge with murine alveolar macrophages (AMΦs, and reduced virulence in a non-neutropenic murine model. ΔaceA survival is remediated by dampening of host ROI (chemically or genetically or enhancement of copper-exporting activity (CrpA in A. fumigatus. Our study exposes a complex host/microbe multifactorial interplay that highlights the importance of host immune status and reveals key targetable A. fumigatus counter-defenses.

  5. Posttranslational regulation of copper transporters

    NARCIS (Netherlands)

    van den Berghe, P.V.E.

    2009-01-01

    The transition metal copper is an essential cofactor for many redox-active enzymes, but excessive copper can generate toxic reactive oxygen species. Copper homeostasis is maintained by highly conserved proteins, to balance copper uptake, distribution and export on the systemic and cellular level.

  6. COPPER CABLE RECYCLING TECHNOLOGY

    International Nuclear Information System (INIS)

    Chelsea Hubbard

    2001-01-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  7. An Investigation of Low Biofouling Copper-charged Membranes

    Science.gov (United States)

    Asapu, Sunitha

    Water is essential for the survival of life on Earth, but pollutants in water can cause dangerous diseases and fatalities. The need for purified water has been increasing with increasing world population; however, natural sources of water such as rivers, lakes and streams, are progressively falling shorter and shorter of meeting water needs. The provision of clean, drinkable water to people is a key factor for the development of novel and alternative water purification technologies, such as membrane separations. Nanofiltration (NF) is a membrane separations technology that purifies water from lower quality sources, such as brackish water, seawater and wastewater. During the filtration of such sources, materials that are rejected by the membrane may accumulate on the surface of the membrane to foul it. Such materials include organic and inorganic matter, colloids, salts and microorganisms. The former four can often be controlled via pretreatment; however, the accumulation of microorganisms is more problematic to membranes. Biofouling is the accumulation and growth of microorganisms on the surface of membranes and on feed spacers. After attachment, microorganisms excrete extracellular polymeric substances (EPS), which form a matrix around the organism's outer surface as biofilm. These biofilms are detrimental and result in irreversible membrane fouling. Copper and silver ions inactivate the bacterial cells and prevent the DNA replication in microbial cells. Previous studies using copper-charged feed spacers have shown the ability of copper to control biofouling without a significant amount of copper leaching from copper-charged polypropylene (PP) feed spacers during crossflow filtration. Also, filtration using unmodified speed facers experienced almost 70% flux decline, while filtration using copper-charged feed spacers displayed only 25% flux decline. These intriguing results led to the hypothesis that the polymer chemistry could be extrapolated to produce membranes

  8. The E1 copper binding domain of full-length amyloid precursor protein mitigates copper-induced growth inhibition in brain metastatic prostate cancer DU145 cells

    Energy Technology Data Exchange (ETDEWEB)

    Gough, Mallory, E-mail: m.gough1@lancaster.ac.uk; Blanthorn-Hazell, Sophee, E-mail: s.blanthorn-hazell@lancaster.ac.uk; Delury, Craig, E-mail: c.delury@lancaster.ac.uk; Parkin, Edward, E-mail: e.parkin@lancaster.ac.uk

    2014-10-31

    Highlights: • Copper levels are elevated in the tumour microenvironment. • APP mitigates copper-induced growth inhibition of DU145 prostate cancer (PCa) cells. • The APP intracellular domain is a prerequisite; soluble forms have no effect. • The E1 CuBD of APP is also a prerequisite. • APP copper binding potentially mitigates copper-induced PCa cell growth inhibition. - Abstract: Copper plays an important role in the aetiology and growth of tumours and levels of the metal are increased in the serum and tumour tissue of patients affected by a range of cancers including prostate cancer (PCa). The molecular mechanisms that enable cancer cells to proliferate in the presence of elevated copper levels are, therefore, of key importance in our understanding of tumour growth progression. In the current study, we have examined the role played by the amyloid precursor protein (APP) in mitigating copper-induced growth inhibition of the PCa cell line, DU145. A range of APP molecular constructs were stably over-expressed in DU145 cells and their effects on cell proliferation in the presence of copper were monitored. Our results show that endogenous APP expression was induced by sub-toxic copper concentrations in DU145 cells and over-expression of the wild-type protein was able to mitigate copper-induced growth inhibition via a mechanism involving the cytosolic and E1 copper binding domains of the full-length protein. APP likely represents one of a range of copper binding proteins that PCa cells employ in order to ensure efficient proliferation despite elevated concentrations of the metal within the tumour microenvironment. Targeting the expression of such proteins may contribute to therapeutic strategies for the treatment of cancers.

  9. Lipid accumulation and alkaline phosphatase activity in human ...

    African Journals Online (AJOL)

    Background: Alkaline phosphatase (ALP) controls intracellular lipid accumulation in human preadipocytes, but it is not known whether ALP is expressed in all body fat depots, or whether it has a similar role at all sites. Design: Cross-sectional. Setting and subjects: Subjects undergoing breast reduction and abdominal fat ...

  10. Lipid accumulation and alkaline phosphatase activity in human ...

    African Journals Online (AJOL)

    2012-10-03

    Oct 3, 2012 ... Background: Alkaline phosphatase (ALP) controls intracellular lipid accumulation in human preadipocytes, but it is not known whether ALP .... glutamine, supplemented with 10% foetal bovine serum and 100 U/ml penicillin ..... by a cascade of transcription factor gene expression.34. Evidence that ALP acts ...

  11. Optimization of carbon dioxide fixation and starch accumulation by ...

    African Journals Online (AJOL)

    ... are very important to CO2 bio-fixation and carbohydrate accumulation in microalgae. The objective of this study was to optimize semi-continuous culture conditions of Tetraselmis subcordiformis in a rectangular airlift photobioreactor for obtaining maximized carbon dioxide fixation rate and intracellular starch productivity.

  12. Role of copper in regression of cardiac hypertrophy.

    Science.gov (United States)

    Zheng, Lily; Han, Pengfei; Liu, Jiaming; Li, Rui; Yin, Wen; Wang, Tao; Zhang, Wenjing; Kang, Y James

    2015-04-01

    Pressure overload causes an accumulation of homocysteine in the heart, which is accompanied by copper depletion through the formation of copper-homocysteine complexes and the excretion of the complexes. Copper supplementation recovers cytochrome c oxidase (CCO) activity and promotes myocardial angiogenesis, along with the regression of cardiac hypertrophy and the recovery of cardiac contractile function. Increased copper availability is responsible for the recovery of CCO activity. Copper promoted expression of angiogenesis factors including vascular endothelial growth factor (VEGF) in endothelial cells is responsible for angiogenesis. VEGF receptor-2 (VEGFR-2) is critical for hypertrophic growth of cardiomyocytes and VEGFR-1 is essential for the regression of cardiomyocyte hypertrophy. Copper, through promoting VEGF production and suppressing VEGFR-2, switches the VEGF signaling pathway from VEGFR-2-dependent to VEGFR-1-dependent, leading to the regression of cardiomyocyte hypertrophy. Copper is also required for hypoxia-inducible factor-1 (HIF-1) transcriptional activity, acting on the interaction between HIF-1 and the hypoxia responsible element and the formation of HIF-1 transcriptional complex by inhibiting the factor inhibiting HIF-1. Therefore, therapeutic targets for copper supplementation-induced regression of cardiac hypertrophy include: (1) the recovery of copper availability for CCO and other critical cellular events; (2) the activation of HIF-1 transcriptional complex leading to the promotion of angiogenesis in the endothelial cells by VEGF and other factors; (3) the activation of VEGFR-1-dependent regression signaling pathway in the cardiomyocytes; and (4) the inhibition of VEGFR-2 through post-translational regulation in the hypertrophic cardiomyocytes. Future studies should focus on target-specific delivery of copper for the development of clinical application. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Copper binding to the N-terminal metal-binding sites or the CPC motif is not essential for copper-induced trafficking of the human Wilson protein (ATP7B)

    Science.gov (United States)

    Cater, Michael A.; La fontaine, Sharon; Mercer, Julian F. B.

    2006-01-01

    The Wilson protein (ATP7B) is a copper-translocating P-type ATPase that mediates the excretion of excess copper from hep-atocytes into bile. Excess copper causes the protein to traffic from the TGN (trans-Golgi network) to subapical vesicles. Using site-directed mutagenesis, mutations known or predicted to abrogate catalytic activity (copper translocation) were introduced into ATP7B and the effect of these mutations on the intracellular traf-ficking of the protein was investigated. Mutation of the critical aspartic acid residue in the phosphorylation domain (DKTGTIT) blocked copper-induced redistribution of ATP7B from the TGN, whereas mutation of the phosphatase domain [TGE (Thr-Gly-Glu)] trapped ATP7B at cytosolic vesicular compartments. Our findings demonstrate that ATP7B trafficking is regulated with its copper-translocation cycle, with cytosolic vesicular localization associated with the acyl-phosphate intermediate. In addition, mut-ation of the six N-terminal metal-binding sites and/or the trans-membrane CPC (Cys-Pro-Cys) motif did not suppress the consti-tutive vesicular localization of the ATP7B phosphatase domain mutant. These results suggested that copper co-ordination by these sites is not essential for trafficking. Importantly, copper-chelation studies with these mutants clearly demonstrated a requirement for copper in ATP7B trafficking, suggesting the presence of an additional copper-binding site(s) within the protein. The results presented in this report significantly advance our understanding of the regulatory mechanism that links copper-translocation activity with copper-induced intracellular trafficking of ATP7B, which is central to hepatic and hence systemic copper homoeostasis. PMID:16939419

  14. Copper resistance determinants in bacteria.

    Science.gov (United States)

    Brown, N L; Rouch, D A; Lee, B T

    1992-01-01

    Copper is an essential trace element that is utilized in a number of oxygenases and electron transport proteins, but it is also a highly toxic heavy metal, against which all organisms must protect themselves. Known bacterial determinants of copper resistance are plasmid-encoded. The mechanisms which confer resistance must be integrated with the normal metabolism of copper. Different bacteria have adopted diverse strategies for copper resistance, and this review outlines what is known about bacterial copper resistance mechanisms and their genetic regulation.

  15. Intracellular Ca2+ Regulation in Calcium Sensitive Phenotype of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    HERMANSYAH

    2010-03-01

    Full Text Available Intracellular cytosolic Ca2+ concentration accumulation plays an essential information in Saccharomyces cerevisiae i.e. to explain cellular mechanism of Ca2+ sensitive phenotype. Disruption both S. cerevisiae PPase PTP2 and MSG5 genes showed an inhibited growth in the presence of Ca2+. On the other hand, by using Luminocounter with apoaequorin system, a method based upon luminescent photoprotein aequorin, intracellular Ca2+ concentration was accumulated as a consequence of calcium sensitive phenotype of S. cerevisiae. This fact indicated that PPase ptp2Δ and msg5Δ were involved in intracellular Ca2+ transport in addition their already known pathways i.e Mitogen Activated Protein Kinase cell wall integrity pathway, high osmolarity glycerol (HOG pathway, and pheromone response FUS3 pathway.

  16. Biosynthesis of intestinal microvillar proteins. Low temperature arrests both processing and intracellular transport

    DEFF Research Database (Denmark)

    Danielsen, E M; Hansen, Gert Helge; Cowell, G M

    1989-01-01

    The effect of culture at 20 degrees C on biosynthesis of microvillar enzymes was studied in pig small intestinal mucosal explants. At this temperature, aminopeptidase N (EC 3.4.11.2) and sucrase-isomaltase (EC 3.2.1.48-10) both accumulated intracellularly, predominantly in their transient, high m...

  17. Biosynthesis of intestinal microvillar proteins. Low temperature arrests both processing and intracellular transport

    DEFF Research Database (Denmark)

    Danielsen, E M; Hansen, Gert Helge; Cowell, G M

    1989-01-01

    The effect of culture at 20 degrees C on biosynthesis of microvillar enzymes was studied in pig small intestinal mucosal explants. At this temperature, aminopeptidase N (EC 3.4.11.2) and sucrase-isomaltase (EC 3.2.1.48-10) both accumulated intracellularly, predominantly in their transient, high...

  18. Accumulation of some metal ions on Bacillus licheniformis

    International Nuclear Information System (INIS)

    Hafez, M.B.; El-Desouky, W.; Fouad, A.

    2001-01-01

    Pure species of Bacillus licheniformis was used to remove ions from aqueous and simulated waste solutions. Metal ion accumulation on B. licheniformis was fast. Maximum uptake occurred at pH 4± 0.5 and at 25 ± 3 deg C. One gram of dry B. licheniformis was found to accumulate 115 mg cerium, 34 mg copper and 11 mg cobalt from aqueous solutions. The presence of certain foreign ions such as calcium, sodium and potassium decreased the uptake of ions by B. licheniformis, while citrate and EDTA prevent the uptake. Electron microscopic investigations showed that cerium (III), copper (II) and cobalt (II) accumulated extracellulary around the surface wall of B. licheniformis cells. A bio-adsorption mechanism between the metal ions and B. licheniformis cell wall was proposed. (author)

  19. Antioxidant enzymes as bio-markers for copper tolerance in ...

    African Journals Online (AJOL)

    Safflower (Carthamus tinctorius L.) plants were exposed to 100 μM copper (Cu) for two weeks under controlled environmental conditions using hydroponic culture. Cu induced changes in chlorophyll and carotenoids pigments. More Cu accumulated in the roots as compared with the leaves. Level of lipid peroxidation and ...

  20. Micromachining with copper lasers

    Science.gov (United States)

    Knowles, Martyn R. H.; Bell, Andy; Foster-Turner, Gideon; Rutterford, Graham; Chudzicki, J.; Kearsley, Andrew J.

    1997-04-01

    In recent years the copper laser has undergone extensive development and has emerged as a leading and unique laser for micromachining. The copper laser is a high average power (10 - 250 W), high pulse repetition rate (2 - 32 kHz), visible laser (511 nm and 578 nm) that produces high peak power (typically 200 kW), short pulses (30 ns) and very good beam quality (diffraction limited). This unique set of laser parameters results in exceptional micro-machining in a wide variety of materials. Typical examples of the capabilities of the copper laser include the drilling of small holes (10 - 200 micrometer diameter) in materials as diverse as steel, ceramic, diamond and polyimide with micron precision and low taper (less than 1 degree) cutting and profiling of diamond. Application of the copper laser covers the electronic, aerospace, automotive, nuclear, medical and precision engineering industries.

  1. Sliding Friction of Copper

    National Research Council Canada - National Science Library

    Liu, Tung

    1963-01-01

    .... With less clean surfaces, the coefficient of friction obtained was about 0.4. Since the degree of cleanliness cannot be controlled quantitatively, the friction - load curve of sliding copper pairs in air exhibits a bifurcation characteristic...

  2. MR imaging of intracellular and extracellular deoxyhemoglobin

    International Nuclear Information System (INIS)

    Janick, P.A.; Grossman, R.I.; Asakura, T.

    1989-01-01

    MR imaging was performed on varying concentrations of intracellular and extracellular deoxyhemoglobin as well as varying proportions of deoxyhemoglobin and oxyhemoglobin in vitro at 1.5T with use of standard spin-echo and gradient-refocused spin sequences. This study indicates that susceptibility-induced T2 shortening occurs over a broad range of intracellular deoxyhemoglobin concentrations (maximal at hematocrits between 20% and 45%), reflecting diffusional effects at the cellular level. T2* gradient-echo imaging enhances the observed hypointensity in images of intracellular deoxyhemoglobin. The characteristic MR appearance of acute hemotomas can be modeled by the behavior of intracellular and extracellular deoxyhemoglobin and oxyhemoglobin

  3. LEP copper accelerating cavities

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    These copper cavities were used to generate the radio frequency electric field that was used to accelerate electrons and positrons around the 27-km Large Electron-Positron (LEP) collider at CERN, which ran from 1989 to 2000. The copper cavities were gradually replaced from 1996 with new superconducting cavities allowing the collision energy to rise from 90 GeV to 200 GeV by mid-1999.

  4. Gene expression patterns in the progression of canine copper-associated chronic hepatitis.

    Directory of Open Access Journals (Sweden)

    Karen Dirksen

    Full Text Available Copper is an essential trace element, but can become toxic when present in abundance. The severe effects of copper-metabolism imbalance are illustrated by the inherited disorders Wilson disease and Menkes disease. The Labrador retriever dog breed is a novel non-rodent model for copper-storage disorders carrying mutations in genes known to be involved in copper transport. Besides disease initiation and progression of copper accumulation, the molecular mechanisms and pathways involved in progression towards copper-associated chronic hepatitis still remain unclear. Using expression levels of targeted candidate genes as well as transcriptome micro-arrays in liver tissue of Labrador retrievers in different stages of copper-associated hepatitis, pathways involved in progression of the disease were studied. At the initial phase of increased hepatic copper levels, transcriptomic alterations in livers mainly revealed enrichment for cell adhesion, developmental, inflammatory, and cytoskeleton pathways. Upregulation of targeted MT1A and COMMD1 mRNA shows the liver's first response to rising intrahepatic copper concentrations. In livers with copper-associated hepatitis mainly an activation of inflammatory pathways is detected. Once the hepatitis is in the chronic stage, transcriptional differences are found in cell adhesion adaptations and cytoskeleton remodelling. In view of the high similarities in copper-associated hepatopathies between men and dog extrapolation of these dog data into human biomedicine seems feasible.

  5. Interaction between copper and radiocesium in Indian mustard and sunflower grown in the hydroponic solution

    International Nuclear Information System (INIS)

    Shirong Tang; Xiaochang Wang

    2002-01-01

    Both Indian mustard and sunflower were grown in a hydroponic solution treated with different concentration activities of 134 Cs or with different amounts of copper or with both in order to investigate the interaction between copper and radiocesium. It was found that 134 Cs activity concentration applied in the nutrient solution exerted more influence on the uptake and translocation of copper by Indian mustard than by sunflower. Indian mustard grown in hydroponic solution containing certain levels of copper and being treated with higher 134 Cs activity concentration showed higher uptake of copper than sunflower. However, in the case of root copper concentrations, sunflower showed significantly higher copper immobilization by roots than Indian mustard. It was also found that the presence of copper the the hydroponic solution did modify radiocesium uptake by both species. The application of 1 mg/l in the growth medium could greatly increase the uptake of 134 Cs by both species. With 3 mg/l concentration of copper amended to the solution, the accumulation of 134 Cs by both species was decreased compared to the 1 mg/l copper treatment. These lines of evidence show that there is stronger interaction between copper and radiocesium in Indian mustard than in sunflower during the root uptake through nutrient solution. (author)

  6. Evaluation of Intracellular Signaling Downstream Chimeric Antigen Receptors.

    Directory of Open Access Journals (Sweden)

    Hannah Karlsson

    Full Text Available CD19-targeting CAR T cells have shown potency in clinical trials targeting B cell leukemia. Although mainly second generation (2G CARs carrying CD28 or 4-1BB have been investigated in patients, preclinical studies suggest that third generation (3G CARs with both CD28 and 4-1BB have enhanced capacity. However, little is known about the intracellular signaling pathways downstream of CARs. In the present work, we have analyzed the signaling capacity post antigen stimulation in both 2G and 3G CARs. 3G CAR T cells expanded better than 2G CAR T cells upon repeated stimulation with IL-2 and autologous B cells. An antigen-driven accumulation of CAR+ cells was evident post antigen stimulation. The cytotoxicity of both 2G and 3G CAR T cells was maintained by repeated stimulation. The phosphorylation status of intracellular signaling proteins post antigen stimulation showed that 3G CAR T cells had a higher activation status than 2G. Several proteins involved in signaling downstream the TCR were activated, as were proteins involved in the cell cycle, cell adhesion and exocytosis. In conclusion, 3G CAR T cells had a higher degree of intracellular signaling activity than 2G CARs which may explain the increased proliferative capacity seen in 3G CAR T cells. The study also indicates that there may be other signaling pathways to consider when designing or evaluating new generations of CARs.

  7. Using Xas And Sxrf to Study Copper in Wilson Disease at the Molecular And Tissue Level

    Energy Technology Data Exchange (ETDEWEB)

    Ralle, M.; Blackburn, N.J.; Lutsenko, S.

    2009-06-05

    Wilson disease (WD) is a genetic disorder of copper metabolism associated with severe hepatic, neurological, and psychiatric abnormalities. In WD, the billiary copper excretion is impaired and copper accumulates in tissues, particularly in the liver and the brain. The affected gene, ATP7B, encodes the copper transporting ATPase, Wilson disease protein (WNDP). WNDP has six copper binding sites in the N-terminal portion of the molecule. Each site includes the conserved amino acid sequence MXCXXC, and binds 1 Cu(I) through its 2 cysteine residues. We performed X-ray absorption studies at the Cu K{sub {alpha}}-edge on the recombinant N-terminal domain of WNDP (N-WNDP). Copper was bound to N-WNDP either in vivo or in vitro in the presence of different reducing agents. We found that in N-WNDP copper is predominantly coordinated in a linear fashion by two cysteines, with the appearance of a Cu-Cu interaction when all metal binding sites are filled. Increasing amounts of reducing agents containing sulfide or phosphine groups led to binding of the exogenous ligands to copper thereby increasing the coordination number of copper from two to three. To better understand the role of copper in WD, we utilized livers of the 6-weeks-old Atp7b-/- mice (an animal model for WD) in which the copper concentration was 10--20-fold higher compared to that of the control mice. The distribution of copper in hepatocytes was evaluated by synchrotron based X-ray fluorescence microprobe (SXRF). We demonstrate that we can prepare liver slices that retain copper and can detect copper with subcellular resolution. On the same sections {mu}-XANES (spot size: 5 micron) was used to determine the oxidation state of copper.

  8. Using XAS and SXRF to Study Copper in Wilson Disease at the Molecular and Tissue Level

    Science.gov (United States)

    Ralle, Martina; Blackburn, Ninian J.; Lutsenko, Svetlana

    2007-02-01

    Wilson disease (WD) is a genetic disorder of copper metabolism associated with severe hepatic, neurological, and psychiatric abnormalities. In WD, the billiary copper excretion is impaired and copper accumulates in tissues, particularly in the liver and the brain. The affected gene, ATP7B, encodes the copper transporting ATPase, Wilson disease protein (WNDP). WNDP has six copper binding sites in the N-terminal portion of the molecule. Each site includes the conserved amino acid sequence MXCXXC, and binds 1 Cu(I) through its 2 cysteine residues. We performed X-ray absorption studies at the Cu Kα-edge on the recombinant N-terminal domain of WNDP (N-WNDP). Copper was bound to N-WNDP either in vivo or in vitro in the presence of different reducing agents. We found that in N-WNDP copper is predominantly coordinated in a linear fashion by two cysteines, with the appearance of a Cu-Cu interaction when all metal binding sites are filled. Increasing amounts of reducing agents containing sulfide or phosphine groups led to binding of the exogenous ligands to copper thereby increasing the coordination number of copper from two to three. To better understand the role of copper in WD, we utilized livers of the 6-weeks-old Atp7b-/- mice (an animal model for WD) in which the copper concentration was 10-20-fold higher compared to that of the control mice. The distribution of copper in hepatocytes was evaluated by synchrotron based X-ray fluorescence microprobe (SXRF). We demonstrate that we can prepare liver slices that retain copper and can detect copper with subcellular resolution. On the same sections μ-XANES (spot size: 5 micron) was used to determine the oxidation state of copper.

  9. Susceptibility of Opportunistic Burkholderia glumae to Copper Surfaces Following Wet or Dry Surface Contact

    Directory of Open Access Journals (Sweden)

    Zhouqi Cui

    2014-07-01

    Full Text Available Burkholderia glumae has been proposed to have a potential risk to vulnerable communities. In this work, we investigated the antibacterial activity and mechanism of copper surfaces against multi-drug resistant B. glumae from both patients and rice plants. The susceptibility of B. glumae to copper surfaces was noted by a significant decline in viable bacterial counts, relative to the slight reduction of stainless steel and polyvinylchloride, both of which were used as control surfaces. The mode of action of bacterial killing was determined by examing the mutagenicity, DNA damage, copper ions accumulation, and membrane damage in bacterial cells. The results indicated that the cells exposed to copper surfaces did not cause severe DNA lesions or increase the mutation frequencies, but resulted in a loss of cell membrane integrity within minutes. Furthermore, bacterial cells exposed to copper surfaces accumulated significantly higher amounts of copper compared to control surfaces. Overall, this study showed that metallic copper had strong antibacterial effect against B. glumae by causing DNA and membrane damage, cellular accumulation of copper, and cell death following DNA degradation, which could be utilized to reduce the risk of bacterial contamination and infection.

  10. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  11. In vitro toxicity of nanosized copper particles in PC12 cells induced by oxidative stress

    Science.gov (United States)

    Xu, Pengjuan; Xu, Jing; Liu, Shichang; Ren, Guogang; Yang, Zhuo

    2012-06-01

    Recent evidence suggests that some nanomaterials, which are widely used in many fields, have health effects. In order to investigate the cytotoxicity induced by nanosized copper particles (nano-Cu), PC12 cells, which were widely used as an in vitro model for the neuron research, were treated with different concentrations (0, 1, 10, 30, and 100 μg/mL) of nano-Cu. The cell viability was determined by measurement of the reduction product of 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT). The oxidative stress induced by nano-Cu and its possible mechanism were studied in relation to the generation of reactive oxygen species (ROS) and the cellular activity of superoxide dismutase (SOD). Results showed that incubation of PC12 cells with increasing concentrations of nano-Cu induced a decrease of cell viability in a concentration- and time-dependent manner. In addition, flow cytometry assay using Annexin V-FITC/PI staining was used to investigate the mode of nano-Cu-induced cell death and quantified the percentage of apoptotic cells. Results showed that nano-Cu induced the significant apoptosis in PC12 cells. Meanwhile, intracellular accumulation of ROS was increased with the increased concentrations of nano-Cu and it was associated with decreased SOD activity, which was probably due to protect effects against the oxidative stress in PC12 cells. Results suggested that both excessive intracellular ROS and decreased SOD contributed to nano-Cu-induced cytotoxicity. In other words, the increasing of oxidative stress was a key mechanism in PC12 apoptosis induced by nano-Cu.

  12. Combining -Omics to Unravel the Impact of Copper Nutrition on Alfalfa (Medicago sativa) Stem Metabolism.

    Science.gov (United States)

    Printz, Bruno; Guerriero, Gea; Sergeant, Kjell; Audinot, Jean-Nicolas; Guignard, Cédric; Renaut, Jenny; Lutts, Stanley; Hausman, Jean-Francois

    2016-02-01

    Copper can be found in the environment at concentrations ranging from a shortage up to the threshold of toxicity for plants, with optimal growth conditions situated in between. The plant stem plays a central role in transferring and distributing minerals, water and other solutes throughout the plant. In this study, alfalfa is exposed to different levels of copper availability, from deficiency to slight excess, and the impact on the metabolism of the stem is assessed by a non-targeted proteomics study and by the expression analysis of key genes controlling plant stem development. Under copper deficiency, the plant stem accumulates specific copper chaperones, the expression of genes involved in stem development is decreased and the concentrations of zinc and molybdenum are increased in comparison with the optimum copper level. At the optimal copper level, the expression of cell wall-related genes increases and proteins playing a role in cell wall deposition and in methionine metabolism accumulate, whereas copper excess imposes a reduction in the concentration of iron in the stem and a reduced abundance of ferritins. Secondary ion mass spectrometry (SIMS) analysis suggests a role for the apoplasm as a copper storage site in the case of copper toxicity. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  13. Copper Uptake in Mammary Epithelial Cells Activates Cyclins and Triggers Antioxidant Response

    Directory of Open Access Journals (Sweden)

    Nathália Villa dos Santos

    2015-01-01

    Full Text Available The toxicologic effects of copper (Cu on tumor cells have been studied during the past decades, and it is suggested that Cu ion may trigger antiproliferative effects in vitro. However, in normal cells the toxicologic effects of high exposures of free Cu are not well understood. In this work, Cu uptake, the expression of genes associated with cell cycle regulation, and the levels of ROS production and related oxidative processes were evaluated in Cu-treated mammary epithelial MCF10A nontumoral cells. We have shown that the Cu additive is associated with the activation of cyclin D1 and cyclin B1, as well as cyclin-dependent kinase 2 (CDK2. These nontumor cells respond to Cu-induced changes in the oxidative balance by increase of the levels of reduced intracellular glutathione (GSH, decrease of reactive oxygen species (ROS generation, and accumulation during progression of the cell cycle, thus preventing the cell abnormal proliferation or death. Taken together, our findings revealed an effect that contributes to prevent a possible damage of normal cells exposed to chemotherapeutic effects of drugs containing the Cu ion.

  14. Copper-induced activation of TRP channels promotes extracellular calcium entry and activation of CaMs and CDPKs leading to copper entry and membrane depolarization in Ulva compressa

    Directory of Open Access Journals (Sweden)

    Melissa eGómez

    2015-03-01

    Full Text Available In order to identify channels involved in membrane depolarization, Ulva compressa was incubated with agonists of TRP channels C5, A1 and V1 and the level of intracellular calcium was detected. Agonists of TRPC5, A1 and V1 induced increases in intracellular calcium at 4, 9 and 12 min of exposure, respectively, and antagonists of TRPC5, A1 and V1 corresponding to SKF-96365 (SKF, HC-030031 (HC and capsazepin (CPZ, respectively, inhibited calcium increases indicating that functional TRPs exist in U. compressa. In addition, copper excess induced increases in intracellular calcium at 4, 9 and 12 min which were inhibited by SKF, HC and CPZ, respectively, indicating that copper activate TRPC5, A1 and V1 channels. Moreover, copper-induced calcium increases were inhibited by EGTA, a non-permeable calcium chelating agent, but not by thapsigargin, an inhibitor of endoplasmic reticulum (ER calcium ATPase, indicating that activation of TRPs leads to extracellular calcium entry. Furthermore, copper-induced calcium increases were not inhibited by W-7, an inhibitor of CaMs, and staurosporine, an inhibitor of CDPKs, indicating that extracellular calcium entry did not require CaMs and CDPKs activation. In addition, copper induced membrane depolarization events at 4, 8 and 11 min and these events were inhibited by SKF, HC, CPZ and bathocuproine, a specific copper chelating agent, indicating copper entry through TRP channels leading to membrane depolarization. Moreover, membrane depolarization events were inhibited by W-7 and staurosporine, indicating that CaMs and CDPKs are required in order to activate TRPs to allow copper entry. Thus, light-dependent copper-induced activation TRPC5, A1 and V1 promotes extracellular calcium entry leading to activation of CaMs and CDPKs which, in turn, promotes copper entry through these TRP channels leading to membrane depolarization.

  15. Copper induces hepatocyte injury due to the endoplasmic reticulum stress in cultured cells and patients with Wilson disease

    Energy Technology Data Exchange (ETDEWEB)

    Oe, Shinji, E-mail: ooes@med.uoeh-u.ac.jp; Miyagawa, Koichiro, E-mail: koichiro@med.uoeh-u.ac.jp; Honma, Yuichi, E-mail: y-homma@med.uoeh-u.ac.jp; Harada, Masaru, E-mail: msrharada@med.uoeh-u.ac.jp

    2016-09-10

    Copper is an essential trace element, however, excess copper is harmful to human health. Excess copper-derived oxidants contribute to the progression of Wilson disease, and oxidative stress induces accumulation of abnormal proteins. It is known that the endoplasmic reticulum (ER) plays an important role in proper protein folding, and that accumulation of misfolded proteins disturbs ER homeostasis resulting in ER stress. However, copper-induced ER homeostasis disturbance has not been fully clarified. We treated human hepatoma cell line (Huh7) and immortalized-human hepatocyte cell line (OUMS29) with copper and chemical chaperones, including 4-phenylbutyrate and ursodeoxycholic acid. We examined copper-induced oxidative stress, ER stress and apoptosis by immunofluorescence microscopy and immunoblot analyses. Furthermore, we examined the effects of copper on carcinogenesis. Excess copper induced not only oxidative stress but also ER stress. Furthermore, excess copper induced DNA damage and reduced cell proliferation. Chemical chaperones reduced this copper-induced hepatotoxicity. Excess copper induced hepatotoxicity via ER stress. We also confirmed the abnormality of ultra-structure of the ER of hepatocytes in patients with Wilson disease. These findings show that ER stress plays a pivotal role in Wilson disease, and suggests that chemical chaperones may have beneficial effects in the treatment of Wilson disease.

  16. Copper induces hepatocyte injury due to the endoplasmic reticulum stress in cultured cells and patients with Wilson disease

    International Nuclear Information System (INIS)

    Oe, Shinji; Miyagawa, Koichiro; Honma, Yuichi; Harada, Masaru

    2016-01-01

    Copper is an essential trace element, however, excess copper is harmful to human health. Excess copper-derived oxidants contribute to the progression of Wilson disease, and oxidative stress induces accumulation of abnormal proteins. It is known that the endoplasmic reticulum (ER) plays an important role in proper protein folding, and that accumulation of misfolded proteins disturbs ER homeostasis resulting in ER stress. However, copper-induced ER homeostasis disturbance has not been fully clarified. We treated human hepatoma cell line (Huh7) and immortalized-human hepatocyte cell line (OUMS29) with copper and chemical chaperones, including 4-phenylbutyrate and ursodeoxycholic acid. We examined copper-induced oxidative stress, ER stress and apoptosis by immunofluorescence microscopy and immunoblot analyses. Furthermore, we examined the effects of copper on carcinogenesis. Excess copper induced not only oxidative stress but also ER stress. Furthermore, excess copper induced DNA damage and reduced cell proliferation. Chemical chaperones reduced this copper-induced hepatotoxicity. Excess copper induced hepatotoxicity via ER stress. We also confirmed the abnormality of ultra-structure of the ER of hepatocytes in patients with Wilson disease. These findings show that ER stress plays a pivotal role in Wilson disease, and suggests that chemical chaperones may have beneficial effects in the treatment of Wilson disease.

  17. Trace elements in pacific Dunlin (Calidris alpina pacifica): patterns of accumulation and concentrations in kidneys and feathers

    NARCIS (Netherlands)

    St. Clair, C.T.; Baird, P.; Ydenberg, R.C.; Elner, R.W.; Bendell, L.I.

    2015-01-01

    Trace element concentrations were measured in Pacific Dunlin (Calidris alpina pacifica) to identify factors that influence accumulation and to assess toxicity risks. We report concentrations of cadmium, copper, and zinc in kidneys as well as copper, lead, mercury, selenium and zinc in feathers.

  18. Serpula lacrymans, The Dry Rot Fungus and Tolerance Towards Copper-Based Wood Preservatives

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Clausen, Carol

    2005-01-01

    -rot fungi is thought to be due in part to oxalic acid production and accumulation. Oxalic acid has been implicated in copper tolerance by the formation of copper oxalate crystals. Twelve isolates of the dry rot fungus, S. lacrymans and four other brown rot species were evaluated for weight loss on wood......Serpula lacrymans (Wulfen : Fries) Schröter, the dry rot fungus, is considered the most (Wulfen : Fries) Schröterthe dry rot fungus, is considered the most economically important wood decay fungus in temperate regions of the world i.e. northern Europe, Japan and Australia. Previously copper based...... wood preservatives were the most commonly used preservatives for pressure treatment of wood for building constructions. Because of a suspicion about tolerance toward copper components, a soil block test was undertaken to clarify the effect of two copper based preservatives, copper citrate and ACQ...

  19. Copper toxicity in leaves of Elodea canadensis Michx.

    Science.gov (United States)

    Malec, Przemysław; Maleva, Maria; Prasad, M N V; Strzałka, Kazimierz

    2009-05-01

    Elodea canadensis (Canadian waterweed) has an ability to accumulate and bioconcentrate heavy metals. In this work, selected cellular responses for Cu treatment were studied in leaves of E. canadensis. Short term experiments, i.e. 1 week exposure to 0.5, 1, 5, and 10 microM of Cu indicated that concentrations up to 10 microM Cu causes a pronounced accumulation of photosynthetic pigments, a drastic degradation of soluble proteins with molecular weight above 18 kDa and a rapid accumulation of polypeptides with molecular weight below 14 kDa. The connection of these observations with copper detoxification mechanisms in aquatic macrophytes are discussed.

  20. Intracellular Nitrate of Marine Diatoms as a Driver of Anaerobic Nitrogen Cycling in Sinking Aggregates

    Directory of Open Access Journals (Sweden)

    Anja Kamp

    2016-11-01

    Full Text Available Diatom-bacteria aggregates are key for the vertical transport of organic carbon in the ocean. Sinking aggregates also represent pelagic microniches with intensified microbial activity, oxygen depletion in the center, and anaerobic nitrogen cycling. Since some of the aggregate-forming diatom species store nitrate intracellularly, we explored the fate of intracellular nitrate and its availability for microbial metabolism within anoxic diatom-bacteria aggregates. The ubiquitous nitrate-storing diatom Skeletonema marinoi was studied as both axenic cultures and laboratory-produced diatom-bacteria aggregates. Stable 15N isotope incubations under dark and anoxic conditions revealed that axenic S. marinoi is able to reduce intracellular nitrate to ammonium that is immediately excreted by the cells. When exposed to a light:dark cycle and oxic conditions, S. marinoi stored nitrate intracellularly in concentrations > 60 mmol L-1 both as free-living cells and associated to aggregates. Intracellular nitrate concentrations exceeded extracellular concentrations by three orders of magnitude. Intracellular nitrate was used up within 2-3 days after shifting diatom-bacteria aggregates to dark and anoxic conditions. Thirty-one percent of the diatom-derived nitrate was converted to nitrogen gas, indicating that a substantial fraction of the intracellular nitrate pool of S. marinoi becomes available to the aggregate-associated bacterial community. Only 5% of the intracellular nitrate was reduced to ammonium, while 59% was recovered as nitrite. Hence, aggregate-associated diatoms accumulate nitrate from the surrounding water and sustain complex nitrogen transformations, including loss of fixed nitrogen, in anoxic, pelagic microniches. Additionally, it may be expected that intracellular nitrate not converted before the aggregates have settled onto the seafloor could fuel benthic nitrogen transformations.

  1. Intracellular Nitrate of Marine Diatoms as a Driver of Anaerobic Nitrogen Cycling in Sinking Aggregates

    Science.gov (United States)

    Kamp, Anja; Stief, Peter; Bristow, Laura A.; Thamdrup, Bo; Glud, Ronnie N.

    2016-01-01

    Diatom-bacteria aggregates are key for the vertical transport of organic carbon in the ocean. Sinking aggregates also represent pelagic microniches with intensified microbial activity, oxygen depletion in the center, and anaerobic nitrogen cycling. Since some of the aggregate-forming diatom species store nitrate intracellularly, we explored the fate of intracellular nitrate and its availability for microbial metabolism within anoxic diatom-bacteria aggregates. The ubiquitous nitrate-storing diatom Skeletonema marinoi was studied as both axenic cultures and laboratory-produced diatom-bacteria aggregates. Stable 15N isotope incubations under dark and anoxic conditions revealed that axenic S. marinoi is able to reduce intracellular nitrate to ammonium that is immediately excreted by the cells. When exposed to a light:dark cycle and oxic conditions, S. marinoi stored nitrate intracellularly in concentrations >60 mmol L-1 both as free-living cells and associated to aggregates. Intracellular nitrate concentrations exceeded extracellular concentrations by three orders of magnitude. Intracellular nitrate was used up within 2–3 days after shifting diatom-bacteria aggregates to dark and anoxic conditions. Thirty-one percent of the diatom-derived nitrate was converted to nitrogen gas, indicating that a substantial fraction of the intracellular nitrate pool of S. marinoi becomes available to the aggregate-associated bacterial community. Only 5% of the intracellular nitrate was reduced to ammonium, while 59% was recovered as nitrite. Hence, aggregate-associated diatoms accumulate nitrate from the surrounding water and sustain complex nitrogen transformations, including loss of fixed nitrogen, in anoxic, pelagic microniches. Additionally, it may be expected that intracellular nitrate not converted before the aggregates have settled onto the seafloor could fuel benthic nitrogen transformations. PMID:27847498

  2. Intracellular calcium homeostasis and signaling.

    Science.gov (United States)

    Brini, Marisa; Calì, Tito; Ottolini, Denis; Carafoli, Ernesto

    2013-01-01

    Ca(2+) is a universal carrier of biological information: it controls cell life from its origin at fertilization to its end in the process of programmed cell death. Ca(2+) is a conventional diffusible second messenger released inside cells by the interaction of first messengers with plasma membrane receptors. However, it can also penetrate directly into cells to deliver information without the intermediation of first or second messengers. Even more distinctively, Ca(2+) can act as a first messenger, by interacting with a plasma membrane receptor to set in motion intracellular signaling pathways that involve Ca(2+) itself. Perhaps the most distinctive property of the Ca(2+) signal is its ambivalence: while essential to the correct functioning of cells, Ca(2+) becomes an agent that mediates cell distress, or even (toxic) cell death, if its concentration and movements inside cells are not carefully tuned. Ca(2+) is controlled by reversible complexation to specific proteins, which could be pure Ca(2+) buffers, or which, in addition to buffering Ca(2+), also decode its signal to pass it on to targets. The most important actors in the buffering of cell Ca(2+) are proteins that transport it across the plasma membrane and the membrane of the organelles: some have high Ca(2+) affinity and low transport capacity (e.g., Ca(2+) pumps), others have opposite properties (e.g., the Ca(2+) uptake system of mitochondria). Between the initial event of fertilization, and the terminal event of programmed cell death, the Ca(2+) signal regulates the most important activities of the cell, from the expression of genes, to heart and muscle contraction and other motility processes, to diverse metabolic pathways involved in the generation of cell fuels.

  3. Copper and copper-nickel alloys as zebra mussel antifoulants

    Energy Technology Data Exchange (ETDEWEB)

    Dormon, J.M.; Cottrell, C.M.; Allen, D.G.; Ackerman, J.D.; Spelt, J.K. [Univ. of Toronto, Ontario (Canada)

    1996-04-01

    Copper has been used in the marine environment for decades as cladding on ships and pipes to prevent biofouling by marine mussels (Mytilus edulis L.). This motivated the present investigation into the possibility of using copper to prevent biofouling in freshwater by both zebra mussels and quagga mussels (Dreissena polymorpha and D. bugensis collectively referred to as zebra mussels). Copper and copper alloy sheet proved to be highly effective in preventing biofouling by zebra mussels over a three-year period. Further studies were conducted with copper and copper-nickel mesh (lattice of expanded metal) and screen (woven wire with a smaller hole size), which reduced the amount of copper used. Copper screen was also found to be strongly biofouling-resistant with respect to zebra mussels, while copper mesh reduced zebra mussel biofouling in comparison to controls, but did not prevent it entirely. Preliminary investigations into the mechanism of copper antifouling, using galvanic couples, indicated that the release of copper ions from the surface of the exposed metal into the surrounding water is directly or indirectly responsible for the biofouling resistance of copper.

  4. Electrical conduction in composites containing copper core-copper ...

    Indian Academy of Sciences (India)

    Composites of nanometre-sized copper core-copper oxide shell with diameters in the range 6.1 to 7.3 nm dispersed in a silica gel were synthesised by a technique comprising reduction followed by oxidation of a suitably chosen precursor gel. The hot pressed gel powders mixed with nanometre-sized copper particles ...

  5. Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion

    International Nuclear Information System (INIS)

    Zhang, Shangrong; Wang, Yifan; Li, Shu Jie

    2014-01-01

    Highlights: • Lansoprazole (LPZ) induces cell apoptosis in breast cancer cells. • LPZ markedly inhibits intracellular proton extrusion. • LPZ induces an increase in intracellular ATP level, lysosomal alkalinization and ROS accumulation. - Abstract: The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor

  6. Creep life simulations of EB welded copper overpack

    International Nuclear Information System (INIS)

    Holmstroem, S.; Laukkanen, A.; Andersson, T.

    2013-12-01

    The long term life predictions of copper overpack (sealed by EB welding in Finland) have previously been based on stress estimations that vary over a wide range, typically between 40-100 MPa. These values are usually not based on structural calculation including the EB-weld that increases the complexity of the stress state in the copper overpack. This report will attempt to pinpoint and simulate the stresses and strains developing in the copper overpack during its first decennia of repository service by advanced FEA simulations including the impact of the EB-weld. The main challenge of this work is the extrapolation of the creep strain response of OFP copper to the service relevant loads and temperatures. The uniaxial creep model is translated to a multiaxial constitutive equation form with adequate computational efficiency. The copper overpack strain and stress evolution has been simulated at up to 100 000 years at a conservative constant temperature of 80 deg C with 14 MPa of external pressure. The results indicate rapid creep relaxation in the initial stages after the load has been applied followed by limited creep strain accumulation thereafter. Local elastic-plastic and creep deformation is predicted at the EB weld root with a total strain of below 12 %. The predicted stresses after external loading and short term relaxation are moderate and the impact of weld residual stresses and the lower creep rupture properties of the EB seem not to be detrimental to the predicted long term creep response. The simulation results imply that the most crucial impact on the creep strain accumulation of the copper overpack is related to the OFP copper primary creep properties. The present study predicts sufficiently low creep strains for a 100 000 years canister life with the conservative assumption at a constant temperature of 80 deg C. However a sensitivity study on the impact of primary creep is strongly recommended due to contradicting analysis results from earlier FEA

  7. Fabrication of Copper Nanowire Films and their Incorporation into Polymer Matrices for Antibacterial and Marine Antifouling Applications

    NARCIS (Netherlands)

    Jiang, S.; Sreethawong, T.; Siew Chen Lee, S.; Bee Jin Low, M.; Yin Win, BrzozowskaK.; Brzozowska, A.M.; Lay Ming Teo, S.; Vancso, Gyula J.; Janczewski, D.; Han, M-Y

    2015-01-01

    With the ban of tributyltin, copper-based biocides are now widely used in antifouling coatings as the major active ingredients. Given the past experience of heavy-metal accumulation in harbors with limited water exchange, there is a significant interest in developing copper materials that greatly

  8. Thioredoxin 80-Activated-Monocytes (TAMs) Inhibit the Replication of Intracellular Pathogens

    DEFF Research Database (Denmark)

    Cortes-Bratti, Ximena; Brasseres, Eugenie; Herrera-Rodriquez, Fabiola

    2011-01-01

    for a role of TAMs in the control of intracellular bacterial infections. As model pathogens we have chosen Listeria monocytogenes and Brucella abortus which replicate in the cytosol and the endoplasmic reticulum respectively. Our data indicate that TAMs efficiently inhibit intracellular growth of both L....... monocytogenes and B. abortus. Further analysis shows that Trx80 activation prevents the escape of GFP-tagged L. monocytogenes into the cytosol, and induces accumulation of the bacteria within the lysosomes. Inhibition of the lysosomal activity by chloroquine treatment resulted in higher replication of bacteria...

  9. Time-averaged copper concentrations from continuous exposures predicts pulsed exposure toxicity to the marine diatom, Phaeodactylum tricornutum: Importance of uptake and elimination.

    Science.gov (United States)

    Angel, Brad M; Simpson, Stuart L; Chariton, Anthony A; Stauber, Jenny L; Jolley, Dianne F

    2015-07-01

    Intermittent, fluctuating and pulsed contaminant discharges result in organisms receiving highly variable contaminant exposures. Current water quality guidelines are predominantly derived using data from continuous exposure toxicity tests, and most frequently applied by regulators with the assumption that concentrations from a single sampling event will provide a meaningful approach to assessing potential effects. This study investigated the effect of single and multiple (daily) dissolved copper pulses on the marine diatom, Phaeodactylum tricornutum, including measurements of copper uptake and elimination to investigate the toxic mechanism. Copper pulses of between 0.5 and 24h and continuous exposures with equivalent 72-h time-averaged concentrations (TACs) resulted in similar biomass inhibition of P. tricornutum, with continuous exposures often being marginally more toxic. Rates of cell division generally recovered to control levels within 24h of the copper pulse removal. Upon resuspension in clean seawater, the extracellular copper per cell decreased rapidly, whereas the intracellular copper per cell decreased slowly. Negligible loss of copper from the total algal biomass indicated that P. tricornutum did not have an effective mechanism for eliminating copper from cells, rather the intracellular copper decreased as a result of dilution by cellular division as the algal growth rate recovered. The measurement of copper uptake after 72-h exposure and kinetics of elimination thereafter suggest that continuous exposures are marginally more toxic to P. tricornutum than pulsed copper exposures with equivalent TACs because slow internalization and saturation of algal membrane transport sites results in less copper uptake into pulse-exposed cells than continuously-exposed cells coupled with dilution of internalized copper via cellular division in the post-exposure period. In the case of P. tricornutum, the results indicate that water quality guidelines for copper based on

  10. Brazing copper to dispersion-strengthened copper

    Energy Technology Data Exchange (ETDEWEB)

    Ryding, D.G.; Allen, D.; Lee, R.

    1996-08-01

    The Advanced Photon Source (APS) is a state-of-the-art synchrotron light source that will produce intense x-ray beams, which will allow the study of smaller samples and faster reactions and processes at a greater level of detail that has been possible to date. The beam is produced by using third-generation insertion devices in a 7 GeV electron/positron storage ring that is 1100 meters in circumference. The heat load from these intense high power devices is very high and certain components must sustain total heat loads of 3 to 15 kW and heat fluxes of 30 W/mm{sup 2}. Because the beams will cycle on and off many times, thermal shock and fatigue will be a problem. High heat flux impinging on a small area causes a large thermal gradient that results in high stress. GlidCop{reg_sign}, a dispersion strengthened copper, is the desired material because of its high thermal conductivity and superior mechanical properties as compared to copper and its alloys. GlidCop is not amenable to joining by fusion welding, and brazing requires diligence because of high diffusivity. Brazing procedures were developed using optical and scanning electron microscopy.

  11. Sodium accumulation in rice and quinoa

    International Nuclear Information System (INIS)

    Gorham, J.

    2001-01-01

    Full text: Sensitivity to salinity is often attributed to excessive accumulation of Na + ions in leaf cells. This implies that screening for low Na + accumulation should result in enhanced tolerance to salt. While this is generally true, there are a number of examples where Na + accumulation is not the only factor. In rice (Oryza sativa) there is good evidence linking genetically-determined Na + accumulation with tolerance to salinity, but there are other factors that should be considered, including Cl - accumulation and the inter- and intra-cellular distribution of solutes. In quinoa (Chenopodium quinoa) There are large varietal differences in Na + accumulation, but smaller differences in salt tolerance. We have studied the genetics of salinity responses in two cultivars of rice, Co39 and Moroberekan. The latter accumulates more Na + than Co39 and many other rice varieties. Experiments at a range of salt concentrations and with varying Na: Ca ratios showed that Na + accumulation was initially quite low, but increased with time of exposure to salt. Part of the increase in Na + , and all of the observed increase in K + concentrations, could be attributed to dehydration of the leaves. Measurements of leaf solute and water potentials indicated that solutes accumulated in the leaf apoplast. This resulted in reduced turgor and increased leaf rolling. Concentrations of Cl - in the leaves were several times higher than those of Na + . QTL analysis of a hybrid population derived from these varieties revealed a major QTL for leaf Na + accumulation on chromosome 1 at a position where QTL for salt tolerance and Na + uptake have been identified by other groups. No QTL were identified for Cl - accumulation. Is rice relatively salt sensitive because it accumulates low concentrations of Na + under genetic control, or is Cl - (present at much higher concentrations) responsible for salt damage. We are looking for rice accessions that differ in Cl - accumulation to find Cl - QTL

  12. Copper induced oxidative stresses, antioxidant responses and phytoremediation potential of Moso bamboo (Phyllostachys pubescens)

    Science.gov (United States)

    Chen, Junren; Shafi, Mohammad; Li, Song; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Peng, Danli; Yan, Wenbo; Liu, Dan

    2015-09-01

    Moso bamboo is recognized as phytoremediation plant due to production of huge biomass and high tolerance in stressed environment. Hydroponics and pot experiments were conducted to investigate mechanism of copper tolerance and to evaluate copper accumulation capacity of Moso bamboo. In hydroponics experiment there was non significant variation in MDA contents of leaves compared with control. SOD and POD initially indicated enhancing trend with application of 5 μM Cu and then decreased consistently with application of 25 and 100 μM Cu. Application of each additional increment of copper have constantly enhanced proline contents while maximum increase of proline was observed with application of 100 μM copper. In pot experiment chlorophyll and biomass initially showed increasing tendency and decreased gradually with application of each additional increment of Cu. Normal growth of Moso bamboo was observed with application of 100 mg kg-1 copper. However, additional application of 300 or 600 mg kg-1 copper had significantly inhibited growth of Moso bamboo. The concentration of Cu in Moso bamboo has attained the levels of 340, 60, 23 mg kg-1 in roots, stems and leaves respectively. The vacuoles were the main organs which accumulated copper and reduced toxicity of copper as studied by TEM-DEX technology.

  13. Copper induced oxidative stresses, antioxidant responses and phytoremediation potential of Moso bamboo (Phyllostachys pubescens).

    Science.gov (United States)

    Chen, Junren; Shafi, Mohammad; Li, Song; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Peng, Danli; Yan, Wenbo; Liu, Dan

    2015-09-04

    Moso bamboo is recognized as phytoremediation plant due to production of huge biomass and high tolerance in stressed environment. Hydroponics and pot experiments were conducted to investigate mechanism of copper tolerance and to evaluate copper accumulation capacity of Moso bamboo. In hydroponics experiment there was non significant variation in MDA contents of leaves compared with control. SOD and POD initially indicated enhancing trend with application of 5 μM Cu and then decreased consistently with application of 25 and 100 μM Cu. Application of each additional increment of copper have constantly enhanced proline contents while maximum increase of proline was observed with application of 100 μM copper. In pot experiment chlorophyll and biomass initially showed increasing tendency and decreased gradually with application of each additional increment of Cu. Normal growth of Moso bamboo was observed with application of 100 mg kg(-1) copper. However, additional application of 300 or 600 mg kg(-1) copper had significantly inhibited growth of Moso bamboo. The concentration of Cu in Moso bamboo has attained the levels of 340, 60, 23 mg kg(-1) in roots, stems and leaves respectively. The vacuoles were the main organs which accumulated copper and reduced toxicity of copper as studied by TEM-DEX technology.

  14. Distribution and chemical forms of copper in the root cells of castor seedlings and their tolerance to copper phytotoxicity in hydroponic culture.

    Science.gov (United States)

    Kang, Wei; Bao, Jianguo; Zheng, Jin; Hu, Hongqin; Du, Jiangkun

    2015-05-01

    The subcellular localization and chemical forms of copper in castor (Ricinus communis L.) seedlings grown in hydroponic nutrient solution were identified by chemical extraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The wild castor seeds were harvested from an abandoned copper mine in Tonglu Mountain, Daye City of Hubei Province, China. The results revealed that (1) the seedlings grew naturally in MS liquid medium with 40.00 mg kg(-1) CuSO4, in which the seedling growth rate and biomass index were 0.14 and 1.23, respectively, which were the highest values among all the treatments. The copper content in castor seedlings increased along with elevated CuSO4 concentration in the medium, reaching a maximum value of 16 570.12 mg kg(-1)(DW) when exposed to 60.00 mg L(-1) CuSO4, where 91.31% of the copper was accumulated in roots. (2) The copper existed in various chemical forms in the roots of the castor seedlings. Copper of 67.66% was extracted from the components of cell walls, such as exchangeable acidic polar compounds, cellulose and lignin, protein and pectin, and less concentrated in cell cytoplasm and nuclei. (3) Furthermore, the root cell walls were thickened when the castor seedlings exposed to CuSO4, with a large amount of high-density electron bodies, attached to the thickened cell walls. In the cell walls, most copper was bound to the carboxyl (-COOH) and hydroxyl (-OH) groups of acidic polar compounds, cellulose, hemicellulose, and polysaccharides. The conclusion showed that castor exhibited a strong tolerance to copper, the copper were accumulated mainly in the root cell, the root cell walls of castor were the major location of patience and detoxification in copper stress.

  15. Nanoparticles for intracellular-targeted drug delivery

    International Nuclear Information System (INIS)

    Paulo, Cristiana S O; Pires das Neves, Ricardo; Ferreira, Lino S

    2011-01-01

    Nanoparticles (NPs) are very promising for the intracellular delivery of anticancer and immunomodulatory drugs, stem cell differentiation biomolecules and cell activity modulators. Although initial studies in the area of intracellular drug delivery have been performed in the delivery of DNA, there is an increasing interest in the use of other molecules to modulate cell activity. Herein, we review the latest advances in the intracellular-targeted delivery of short interference RNA, proteins and small molecules using NPs. In most cases, the drugs act at different cellular organelles and therefore the drug-containing NPs should be directed to precise locations within the cell. This will lead to the desired magnitude and duration of the drug effects. The spatial control in the intracellular delivery might open new avenues to modulate cell activity while avoiding side-effects.

  16. and copper(II)

    Indian Academy of Sciences (India)

    Unknown

    characterization of several imidazolate-bridged binuclear copper(II) complexes have been reported 1–17. ... of the desired complex formed were collected, washed with ethanol and dried in vacuo at room temperature. .... 16. Sigel H (ed.) 1981 Metal ions in biological system (New York: Marcel Dekker) vol 13, p. 259. 17.

  17. Presenilin promotes dietary copper uptake.

    Directory of Open Access Journals (Sweden)

    Adam Southon

    Full Text Available Dietary copper is essential for multicellular organisms. Copper is redox active and required as a cofactor for enzymes such as the antioxidant Superoxide Dismutase 1 (SOD1. Copper dyshomeostasis has been implicated in Alzheimer's disease. Mutations in the presenilin genes encoding PS1 and PS2 are major causes of early-onset familial Alzheimer's disease. PS1 and PS2 are required for efficient copper uptake in mammalian systems. Here we demonstrate a conserved role for presenilin in dietary copper uptake in the fly Drosophila melanogaster. Ubiquitous RNA interference-mediated knockdown of the single Drosophila presenilin (PSN gene is lethal. However, PSN knockdown in the midgut produces viable flies. These flies have reduced copper levels and are more tolerant to excess dietary copper. Expression of a copper-responsive EYFP construct was also lower in the midgut of these larvae, indicative of reduced dietary copper uptake. SOD activity was reduced by midgut PSN knockdown, and these flies were sensitive to the superoxide-inducing chemical paraquat. These data support presenilin being needed for dietary copper uptake in the gut and so impacting on SOD activity and tolerance to oxidative stress. These results are consistent with previous studies of mammalian presenilins, supporting a conserved role for these proteins in mediating copper uptake.

  18. Crystal structure of a copper-transporting PIB-type ATPase

    DEFF Research Database (Denmark)

    Gourdon, Pontus Emanuel; Liu, Xiang-Yu; Skjørringe, Tina

    2011-01-01

    Heavy-metal homeostasis and detoxification is crucial for cell viability. P-type ATPases of the class IB (PIB) are essential in these processes, actively extruding heavy metals from the cytoplasm of cells. Here we present the structure of a PIB-ATPase, a Legionella pneumophila CopA Cu......(+)-ATPase, in a copper-free form, as determined by X-ray crystallography at 3.2 Å resolution. The structure indicates a three-stage copper transport pathway involving several conserved residues. A PIB-specific transmembrane helix kinks at a double-glycine motif displaying an amphipathic helix that lines a putative...... copper entry point at the intracellular interface. Comparisons to Ca(2+)-ATPase suggest an ATPase-coupled copper release mechanism from the binding sites in the membrane via an extracellular exit site. The structure also provides a framework to analyse missense mutations in the human ATP7A and ATP7B...

  19. Search of a plant hiperacumuladora of copper

    International Nuclear Information System (INIS)

    Hernandez Colorado, R.R.

    2003-01-01

    The objective of this investigation was to find inside the flora of Costa Rica, a plant copper hiperacumuladora. Once identified the species, you would proceed to cultivate it in vitro, stops later to make experiments of copper absorption in vitro. If the selected species was capable of hiperacumular the metal, the influence of the agents quelantes sour etilendiaminotetraacetico would be investigated (EDTA) and citric acid, in the absorption of the metal. To carry out the investigation, vegetable species were collected inside the banana property Probana located in Limon and inside a coffee plantation in Carrizal de Alajuela. The dried vegetable samples were analyzed the copper content and in the same way, with collected floor samples of the surrounding area to the plants. As satisfactory results were not obtained, the species Tagetes foetidissima and Coccosypselum hirsutum were selected. The first one was selected with base in their metabolism, which allowed to synthesize sulfurated compounds. The second were selected with base in the available information in the literature about the aluminum hiperacumulation on the part of species belonging to the family Rubiaceae, to which it belongs. The species T. foetidissima and C. hirsutum, were cultivated in vitro stops later to make experiments of copper absorption. The results obtained starting from the experiments of copper absorption for T. foetidissima were of 3626 - 7402 mg kg -1 it has more than enough it bases dry, for an environment of concentration of the metal in the means of cultivation of 20-30 mg L -1 for a lapse of fifteen days. For this species an environment of accumulation of 4251 was obtained - 6481 mg kg -1 it has more than enough it bases dry, to 20 mg L -1 of the metal, when adding him EDTA to an experimentation group and citric acid to another. In the case of C. hirsutum, hiperacumulo gets paid in concentrations of 7648 - 8786 mg kg -1 it has more than enough it bases dry, for an environment of

  20. Copper uptake across rainbow trout gills: mechanisms of apical entry

    DEFF Research Database (Denmark)

    Grosell, Martin Hautopp; Wood, C. M.

    2002-01-01

    Copper, Homeostasis, sodium uptake, copper/sodium interactions, gill, rainbow trout, Oncorhynchus mykiss......Copper, Homeostasis, sodium uptake, copper/sodium interactions, gill, rainbow trout, Oncorhynchus mykiss...

  1. Xenoestrogens alter estrogen receptor (ER α intracellular levels.

    Directory of Open Access Journals (Sweden)

    Piergiorgio La Rosa

    Full Text Available 17β-estradiol (E2-dependent estrogen receptor (ER α intracellular concentration is a well recognized critical step in the pleiotropic effects elicited by E2 in several target tissues. Beside E2, a class of synthetic and plant-derived chemicals collectively named endocrine disruptors (EDs or xenoestrogens bind to and modify both nuclear and extra-nuclear ERα activities. However, at the present no information is available on the ability of EDs to hamper ERα intracellular concentration. Here, the effects of bisphenol A (BPA and naringenin (Nar, prototypes of synthetic and plant-derived ERα ligands, have been evaluated on ERα levels in MCF-7 cells. Both EDs mimic E2 in triggering ERα Ser118 phosphorylation and gene transcription. However, only E2 or BPA induce an increase of cell proliferation; whereas 24 hrs after Nar stimulation a dose-dependent decrease in cell number is reported. E2 or BPA treatment reduces ERα protein and mRNA levels after 24 hrs. Contrarily, Nar stimulation does not alter ERα content but reduces ERα mRNA levels like other ligands. Co-stimulation experiments indicate that 48 hrs of Nar treatment prevents the E2-induced ERα degradation and hijacks the physiological ability of E2:ERα complex to regulate gene transcription. Mechanistically, Nar induces ERα protein accumulation by preventing proteasomal receptor degradation via persistent activation of p38/MAPK pathway. As a whole these data demonstrate that ERα intracellular concentration is an important target through which EDs hamper the hormonal milieu of E2 target cells driving cells to different outcomes or mimicking E2 even in the absence of the hormone.

  2. Xenoestrogens alter estrogen receptor (ER) α intracellular levels.

    Science.gov (United States)

    La Rosa, Piergiorgio; Pellegrini, Marco; Totta, Pierangela; Acconcia, Filippo; Marino, Maria

    2014-01-01

    17β-estradiol (E2)-dependent estrogen receptor (ER) α intracellular concentration is a well recognized critical step in the pleiotropic effects elicited by E2 in several target tissues. Beside E2, a class of synthetic and plant-derived chemicals collectively named endocrine disruptors (EDs) or xenoestrogens bind to and modify both nuclear and extra-nuclear ERα activities. However, at the present no information is available on the ability of EDs to hamper ERα intracellular concentration. Here, the effects of bisphenol A (BPA) and naringenin (Nar), prototypes of synthetic and plant-derived ERα ligands, have been evaluated on ERα levels in MCF-7 cells. Both EDs mimic E2 in triggering ERα Ser118 phosphorylation and gene transcription. However, only E2 or BPA induce an increase of cell proliferation; whereas 24 hrs after Nar stimulation a dose-dependent decrease in cell number is reported. E2 or BPA treatment reduces ERα protein and mRNA levels after 24 hrs. Contrarily, Nar stimulation does not alter ERα content but reduces ERα mRNA levels like other ligands. Co-stimulation experiments indicate that 48 hrs of Nar treatment prevents the E2-induced ERα degradation and hijacks the physiological ability of E2:ERα complex to regulate gene transcription. Mechanistically, Nar induces ERα protein accumulation by preventing proteasomal receptor degradation via persistent activation of p38/MAPK pathway. As a whole these data demonstrate that ERα intracellular concentration is an important target through which EDs hamper the hormonal milieu of E2 target cells driving cells to different outcomes or mimicking E2 even in the absence of the hormone.

  3. Intracellular pH gradients in migrating cells

    DEFF Research Database (Denmark)

    Martin, Christine; Pedersen, Stine Helene Falsig; Schwab, Albrecht

    2011-01-01

    Cell polarization along the axis of movement is required for migration. The localization of proteins and regulators of the migratory machinery to either the cell front or its rear results in a spatial asymmetry enabling cells to simultaneously coordinate cell protrusion and retraction. Protons...... might function as such unevenly distributed regulators as they modulate the interaction of focal adhesion proteins and components of the cytoskeleton in vitro. However, an intracellular pH (pH(i)) gradient reflecting a spatial asymmetry of protons has not been shown so far. One major regulator of p......H(i), the Na(+)/H(+) exchanger NHE1, is essential for cell migration and accumulates at the cell front. Here, we test the hypothesis that the uneven distribution of NHE1 activity creates a pH(i) gradient in migrating cells. Using the pH-sensitive fluorescent dye BCECF, pH(i) was measured in five cell lines (MV...

  4. Horizontal Transmission of Intracellular Insect Symbionts via Plants

    Directory of Open Access Journals (Sweden)

    Ewa Chrostek

    2017-11-01

    Full Text Available Experimental evidence is accumulating that endosymbionts of phytophagous insects may transmit horizontally via plants. Intracellular symbionts known for manipulating insect reproduction and altering fitness (Rickettsia, Cardinium, Wolbachia, and bacterial parasite of the leafhopper Euscelidius variegatus have been found to travel from infected insects into plants. Other insects, either of the same or different species can acquire the symbiont from the plant through feeding, and in some cases transfer it to their progeny. These reports prompt many questions regarding how intracellular insect symbionts are delivered to plants and how they affect them. Are symbionts passively transported along the insect-plant-insect path, or do they actively participate in the process? How widespread are these interactions? How does symbiont presence influence the plant? And what conditions are required for the new infection to establish in an insect? From an ecological, evolutionary, and applied perspective, this mode of horizontal transmission could have profound implications if occurring frequently enough or if new stable symbiont infections are established. Transmission of symbionts through plants likely represents an underappreciated means of infection, both in terms of symbiont epidemiology and the movement of symbionts to new host species.

  5. Horizontal Transmission of Intracellular Insect Symbionts via Plants.

    Science.gov (United States)

    Chrostek, Ewa; Pelz-Stelinski, Kirsten; Hurst, Gregory D D; Hughes, Grant L

    2017-01-01

    Experimental evidence is accumulating that endosymbionts of phytophagous insects may transmit horizontally via plants. Intracellular symbionts known for manipulating insect reproduction and altering fitness ( Rickettsia, Cardinium, Wolbachia , and bacterial parasite of the leafhopper Euscelidius variegatus ) have been found to travel from infected insects into plants. Other insects, either of the same or different species can acquire the symbiont from the plant through feeding, and in some cases transfer it to their progeny. These reports prompt many questions regarding how intracellular insect symbionts are delivered to plants and how they affect them. Are symbionts passively transported along the insect-plant-insect path, or do they actively participate in the process? How widespread are these interactions? How does symbiont presence influence the plant? And what conditions are required for the new infection to establish in an insect? From an ecological, evolutionary, and applied perspective, this mode of horizontal transmission could have profound implications if occurring frequently enough or if new stable symbiont infections are established. Transmission of symbionts through plants likely represents an underappreciated means of infection, both in terms of symbiont epidemiology and the movement of symbionts to new host species.

  6. Detection of ubiquitinated huntingtin species in intracellular aggregates

    Directory of Open Access Journals (Sweden)

    Katrin eJuenemann

    2015-01-01

    Full Text Available Protein conformation diseases, including polyglutamine diseases, result from the accumulation and aggregation of misfolded proteins. Huntington’s disease is one of nine diseases caused by an expanded polyglutamine repeat within the affected protein and is hallmarked by intracellular inclusion bodies composed of aggregated N-terminal huntingtin fragments and other sequestered proteins. Fluorescence microscopy and filter trap assay are conventional methods to study protein aggregates, but cannot be used to analyze the presence and levels of post-translational modifications of aggregated huntingtin such as ubiquitination. Ubiquitination of proteins can be a signal for degradation and intracellular localization, but also affects protein activity and protein-protein interactions. The function of ubiquitination relies on its mono- and polymeric isoforms attached to protein substrates. Studying the ubiquitination pattern of aggregated huntingtin fragments offers an important possibility to understand huntingtin degradation and aggregation processes within the cell. For the identification of aggregated huntingtin and its ubiquitinated species, solubilization of the cellular aggregates is mandatory. Here we describe methods to identify post-translational modifications such as ubiquitination of aggregated mutant huntingtin. This approach is specifically described for use with mammalian cell culture and is suitable to study other disease-related proteins prone to aggregate.

  7. Copper toxicity to the fresh water snail, Lymnaea luteola

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, N.M.; Rao, P.V.

    1987-07-01

    Haemocyanins are found in arthropoda and mollusca and show a copper content characteristic for each phylum. Heavy metal accumulation by mollusks is widely reported. Approximately one third of the enzymes either required addition of a metal ion as a cofactor in order to exhibit maximum activity or contained a slightly bound metal ion which appeared to be involved in the catalytic process. Copper is the only metal which has been detected in significant amounts in amino oxidase. The present study is designed to evaluate the influence of such copper, which is of such common occurrence in biological material, on some of the lipolytic enzymes of fresh water pulmonate snail, Lymnaea luteola when added to ambient medium. The present study also highlights the possible detoxification mechanism prevailing in this fresh water mollusk.

  8. ROS dependent copper toxicity in Hydra-biochemical and molecular study.

    Science.gov (United States)

    Zeeshan, Mohammed; Murugadas, Anbazhagan; Ghaskadbi, Surendra; Rajendran, Ramasamy Babu; Akbarsha, Mohammad Abdulkader

    2016-01-01

    Copper, an essential microelement, is known to be toxic to aquatic life at concentrations higher than that could be tolerated. Copper-induced oxidative stress has been documented in vitro, yet the in vivo effects of metal-induced oxidative stress have not been extensively studied in the lower invertebrates. The objective of the present study has been to find the effect of ROS-mediated toxicity of environmentally relevant concentrations of copper at organismal and cellular levels in Hydra magnipapillata. Exposure to copper at sublethal concentrations (0.06 and 0.1mg/L) for 24 or 48h resulted in generation of significant levels of intracellular reactive oxygen species (ROS). We infer that the free radicals here originate predominantly at the lysosomes but partly at the mitochondria also as visualized by H2-DHCFDA staining. Quantitative real-time PCR of RNA extracted from copper-exposed polyps revealed dose-dependent up-regulation of all antioxidant response genes (CAT, SOD, GPx, GST, GR, G6PD). Concurrent increase of Hsp70 and FoxO genes suggests the ability of polyps to respond to stress, which at 48h was not the same as at 24h. Interestingly, the transcript levels of all genes were down-regulated at 48h as compared to 24h incubation period. Comet assay indicated copper as a powerful genotoxicant, and the DNA damage was dose- as well as duration-dependent. Western blotting of proteins (Bax, Bcl-2 and caspase-3) confirmed ROS-mediated mitochondrial cell death in copper-exposed animals. These changes correlated well with changes in morphology, regeneration and aspects of reproduction. Taken together, the results indicate increased production of intracellular ROS in Hydra on copper exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Potential use of copper as a hygienic surface; problems associated with cumulative soiling and cleaning.

    Science.gov (United States)

    Airey, P; Verran, J

    2007-11-01

    It has been suggested that antibacterial copper could be used in place of stainless steel to help reduce the occurrence of hospital-acquired infections. The antibacterial activity of copper has been clearly demonstrated when using cell suspensions held in prolonged contact with copper or copper alloys. The aim of this study was to evaluate the antimicrobial properties of copper in comparison with stainless steel in a generally dry environment. Three stainless steels of varying surface finish and polished copper were soiled with Staphylococcus aureus suspended in a protein-based organic soil (bovine serum album), dried rapidly, and then incubated for 24 h. Surfaces were then wiped clean using a standardised wiping procedure with two cleaning agents recommended by UK National Health Service guidelines. This soiling/cleaning procedure was carried out daily over five days. After each cleaning cycle the amount of residual soil and live cells was assessed using direct epifluorescence microscopy. All materials were easily cleaned after the first soiling episode but a build-up of cells and soil was observed on the copper surfaces after several cleaning/wiping cycles. Stainless steel remained highly cleanable. Accumulation of material on copper is presumably due to the high reactivity of copper, resulting in surface conditioning. This phenomenon will affect subsequent cleaning, aesthetic properties and possibly antibacterial performance. It is important to select the appropriate cleaning/disinfecting protocols for selected surfaces.

  10. Prenatal treatment of mosaic mice (Atp7a mo-ms) mouse model for Menkes disease, with copper combined by dimethyldithiocarbamate (DMDTC)

    DEFF Research Database (Denmark)

    Lenartowicz, Małgorzata; Krzeptowski, Wojciech; Koteja, Paweł

    2012-01-01

    in the kidney in postnatal copper-treated Menkes patients may reach toxic levels. The mouse model, mosaic Atp7a (mo-ms) recapitulates the Menkes phenotype and die about 15.75±1.5 days of age. In the present study we found that prenatal treatment of mosaic murine fetuses throughout gestation days 7, 11, 15......Menkes disease is a fatal neurodegenerative disorder in infants caused by mutations in the gene ATP7A which encodes a copper (Cu) transporter. Defects in ATP7A lead to accumulated copper in the small intestine and kidneys and to copper deficiencies in the brain and the liver. The copper level...

  11. Iron and copper, and their interactions during development.

    Science.gov (United States)

    Gambling, Lorraine; Andersen, Henriette S; McArdle, Harry J

    2008-12-01

    During development, the fetus is entirely dependent on the mother for its nutrient requirements. Subsequently, it is a period when both are vulnerable to changes in dietary supply, especially of those nutrients that are marginal under normal circumstances. In developed countries, this applies mainly to micronutrients. Even now, iron deficiency is a common disorder, especially in pregnancy. Similarly, copper intake in the U.K. population is rarely above adequate levels. It is now becoming clear that nutrient deficiencies during pregnancy can result in problems for the offspring, in both the short- and long-term. Early studies showed that lambs born to mothers on copper-deficient pastures developed 'swayback', with neurological and muscular symptoms that could not be reversed by postnatal supplementation. Our own findings have shown that prenatal iron deficiency results in increased postnatal blood pressure, even though the offspring have normal dietary iron levels from birth. These observations emphasize the importance of iron and copper in growth and development. Complicating the situation further is the fact that copper and iron are known to interact with each other in many ways, including absorption and intracellular transport. However, their interactions during the pregnancy appear to be more complex than during the non-pregnant state. In the present review, we examine the importance of these metals and their interactions, the consequences, both short- and long-term, of deficiency and consider some possible mechanisms whereby these effects may be generated.

  12. Multilevel cycle of anthropogenic copper.

    Science.gov (United States)

    Graedel, T E; van Beers, D; Bertram, M; Fuse, K; Gordon, R B; Gritsinin, A; Kapur, A; Klee, R J; Lifset, R J; Memon, L; Rechberger, H; Spatari, S; Vexler, D

    2004-02-15

    A comprehensive contemporary cycle for stocks and flows of copper is characterized and presented, incorporating information on extraction, processing, fabrication and manufacturing, use, discard, recycling, final disposal, and dissipation. The analysis is performed on an annual basis, ca. 1994, at three discrete governmental unit levels--56 countries or country groups that together comprise essentially all global anthropogenic copper stocks and flows, nine world regions, and the planet as a whole. Cycles for all of these are presented and discussed, and a "best estimate" global copper cycle is constructed to resolve aggregation discrepancies. Among the most interesting results are (1) transformation rates and recycling rates in apparently similar national economies differ by factors of two or more (country level); (2) the discard flows that have the greatest potential for copper recycling are those with low magnitude flows but high copper concentrations--electronics, electrical equipment, and vehicles (regional level); (3) worldwide, about 53% of the copper that was discarded in various forms was recovered and reused or recycled (global level); (4) the highest rate of transfer of discarded copper to repositories is into landfills, but the annual amount of copper deposited in mine tailings is nearly as high (global level); and (5) nearly 30% of copper mining occurred merely to replace copper that was discarded. The results provide a framework for similar studies of other anthropogenic resource cycles as well as a basis for supplementary studies in resource stocks, industrial resource utilization, waste management, industrial economics, and environmental impacts.

  13. Cadmium accumulation by the marine red alga Porphyra umbilicalis

    Energy Technology Data Exchange (ETDEWEB)

    McLean, M.W.; Williamson, F.B.

    1977-01-01

    The characteristics of cadmium accumulation by the marine red alga Porphyra umbilicalis L. in culture are reported. The time course of uptake under various light conditions shows that cadmium is concentrated as the result of an on-going anabolic process and not as a consequence of a pH gradient as provided by photosynthesis. The effect of cycloheximide is in agreement with de novo protein synthesis being a prerequisite for cadmium accumulation. Autoradiography suggests a specific intracellular location for bound cadmium--apparently the nucleus.

  14. Uptake and intracellular accumulation of diamond nanoparticles – a metabolic and cytotoxic study

    Czech Academy of Sciences Publication Activity Database

    Brož, Antonín; Bačáková, Lucie; Štenclová, Pavla; Kromka, Alexander; Potocký, Štěpán

    2017-01-01

    Roč. 8, Aug 10 (2017), s. 1649-1657 ISSN 2190-4286 R&D Projects: GA ČR(CZ) GA17-19968S; GA MŠk LD15003; GA MZd(CZ) NV15-32497A Institutional support: RVO:67985823 ; RVO:68378271 Keywords : cell viability * FTIR * live-cell imaging * MTS * nanodiamond * SAOS-2 cells Subject RIV: EI - Biotechnology ; Bionics OBOR OECD: Biomaterials (as related to medical implants, devices, sensors) Impact factor: 3.127, year: 2016

  15. Intracellular accumulation of bilirubin as a defense mechanism against increased oxidative stress

    Czech Academy of Sciences Publication Activity Database

    Zelenka, Jaroslav; Muchová, L.; Zelenková, M.; Váňová, K.; Vreman, H.J.; Wong, R.J.; Vítek, L.

    2012-01-01

    Roč. 94, č. 8 (2012), s. 1821-1827 ISSN 0300-9084 Grant - others:GA MZd(CZ) NT11327 Institutional research plan: CEZ:AV0Z50110509 Keywords : bilirubin * heme oxygenase * hyperbilirubinemia * lipopolysacccharide * oxidative stress Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.142, year: 2012

  16. Uptake and intracellular accumulation of diamond nanoparticles – a metabolic and cytotoxic study

    Directory of Open Access Journals (Sweden)

    Antonín Brož

    2017-08-01

    Full Text Available Diamond nanoparticles, known as nanodiamonds (NDs, possess several medically significant properties. Having a tailorable and easily accessible surface gives them great potential for use in sensing and imaging applications and as a component of cell growth scaffolds. In this work we investigate in vitro interactions of human osteoblast-like SAOS-2 cells with four different groups of NDs, namely high-pressure high-temperature (HPHT NDs (diameter 18–210 nm, oxygen-terminated, photoluminescent HPHT NDs (diameter 40 nm, oxygen-terminated, detonation NDs (diameter 5 nm, H-terminated, and the same detonation NDs further oxidized by annealing at 450 °C. The influence of the NDs on cell viability and cell count was measured by the mitochondrial metabolic activity test and by counting cells with stained nuclei. The interaction of NDs with cells was monitored by phase contrast live-cell imaging in real time. For both types of oxygen-terminated HPHT NDs, the cell viability and the cell number remained almost the same for concentrations up to 100 µg/mL within the whole range of ND diameters tested. The uptake of hydrogen-terminated detonation NDs caused the viability and the cell number to decrease by 80–85%. The oxidation of the NDs hindered the decrease, but on day 7, a further decrease was observed. While the O-terminated NDs showed mechanical obstruction of cells by agglomerates preventing cell adhesion, migration and division, the H-terminated detonation NDs exhibited rapid penetration into the cells from the beginning of the cultivation period, and also rapid cell congestion and a rapid reduction in viability. These findings are discussed with reference to relevant properties of NDs such as surface chemical bonds, zeta potential and nanoparticle types.

  17. Intracellular vesicles as reproduction elements in cell wall-deficient L-form bacteria.

    Directory of Open Access Journals (Sweden)

    Yves Briers

    Full Text Available Cell wall-deficient bacteria, or L-forms, represent an extreme example of bacterial plasticity. Stable L-forms can multiply and propagate indefinitely in the absence of a cell wall. Data presented here are consistent with the model that intracellular vesicles in Listeria monocytogenes L-form cells represent the actual viable reproductive elements. First, small intracellular vesicles are formed along the mother cell cytoplasmic membrane, originating from local phospholipid accumulation. During growth, daughter vesicles incorporate a small volume of the cellular cytoplasm, and accumulate within volume-expanding mother cells. Confocal Raman microspectroscopy demonstrated the presence of nucleic acids and proteins in all intracellular vesicles, but only a fraction of which reveals metabolic activity. Following collapse of the mother cell and release of the daughter vesicles, they can establish their own membrane potential required for respiratory and metabolic processes. Premature depolarization of the surrounding membrane promotes activation of daughter cell metabolism prior to release. Based on genome resequencing of L-forms and comparison to the parental strain, we found no evidence for predisposing mutations that might be required for L-form transition. Further investigations revealed that propagation by intracellular budding not only occurs in Listeria species, but also in L-form cells generated from different Enterococcus species. From a more general viewpoint, this type of multiplication mechanism seems reminiscent of the physicochemical self-reproducing properties of abiotic lipid vesicles used to study the primordial reproduction pathways of putative prokaryotic precursor cells.

  18. An econometric model of the U.S. secondary copper industry: Recycling versus disposal

    Science.gov (United States)

    Slade, M.E.

    1980-01-01

    In this paper, a theoretical model of secondary recovery is developed that integrates microeconomic theories of production and cost with a dynamic model of scrap generation and accumulation. The model equations are estimated for the U.S. secondary copper industry and used to assess the impacts that various policies and future events have on copper recycling rates. The alternatives considered are: subsidies for secondary production, differing energy costs, and varying ore quality in primary production. ?? 1990.

  19. Bioaccumulation and Depuration of Copper in the Kidney and Liver of a Freshwater Fish, Capoeta fusca

    Directory of Open Access Journals (Sweden)

    Borhan Mansouri

    2016-07-01

    Full Text Available Background: This study aims to investigate the patterns of bioaccumulation and depuration of copper in the selected kidney and liver of Capoeta fusca. Methods: The fish were collected between September and November 2010 from a qanat in Birjand. They were exposed to two types treatments with copper (0.25 and 0.75 mg/L for a period of 41 days. The fish under study were exposed to the above-mentioned sub-lethal concentrations separately for 14 and 21 days (accumulation period. At the end of this period, the remaining fish were kept in tap water (elimination period for 31 and 41 days. Results: The findings showed that the accumulation of copper in lower and higher sub-lethal concentrations was higher in kidney as the mean accumulation of copper on day 21 was 1.9±0.1 μg/g and 2.93±0.47 μg/g respectively, in 0.25 μg/g and 0.75 μg/g concentrations. On the other hand, the results also showed that the depuration level of copper in the given concentrations was higher in liver than kidney. The bioaccumulation and depuration of copper significantly increased in the kidney and liver of C. fusca (P<0.01. Conclusion: Based on the present work, it is concluded that C. fusca has a potential for the rapid accumulation and depuration of copper in freshwater. Also, the results indicate that the fish C. fusca, as representative fish species in the East of Iran, can be a useful bioindicator organism of water contamination with copper.

  20. and copper(II)

    Indian Academy of Sciences (India)

    Unknown

    that the imidazolate-bridged complex is stable over the pH-range 7⋅15–10⋅0. .... copper(II) complex. The observed room temperature magnetic moments are around. 1⋅79 BM, in agreement with a one-spin (S = 1/2) system. 3.2 EPR studies .... (SK) thanks the Council of Scientific & Industrial Research, New Delhi for an.

  1. Copper Pyrimidine based MOFs

    Indian Academy of Sciences (India)

    Cl..Cu.. interactions but restricted ..Cu..N N..Cu interacations. Supramolecular isomers of Br and I are reported for the first time in this paper. [Cu2I(pdz)X2]. Figure S18. Self assembly of the simultaneous presence of tecton {Cu(sol)3X} and {Cu(pdz)(sol)2X} result in [Cu2I(pdz)X2]. 1. Table S3. Copper Pyrimidine based MOFs ...

  2. Mitochondrial calcium signaling mediates rhythmic extracellular ATP accumulation in suprachiasmatic nucleus astrocytes.

    Science.gov (United States)

    Burkeen, Jeff F; Womac, Alisa D; Earnest, David J; Zoran, Mark J

    2011-06-08

    The master circadian pacemaker located within the suprachiasmatic nuclei (SCN) controls neural and neuroendocrine rhythms in the mammalian brain. Astrocytes are abundant in the SCN, and this cell type displays circadian rhythms in clock gene expression and extracellular accumulation of ATP. Still, the intracellular signaling pathways that link the SCN clockworks to circadian rhythms in extracellular ATP accumulation remain unclear. Because ATP release from astrocytes is a calcium-dependent process, we investigated the relationship between intracellular Ca(2+) and ATP accumulation and have demonstrated that intracellular Ca(2+) levels fluctuate in an antiphase relationship with rhythmic ATP accumulation in rat SCN2.2 cell cultures. Furthermore, mitochondrial Ca(2+) levels were rhythmic and maximal in precise antiphase with the peak in cytosolic Ca(2+). In contrast, our finding that peak mitochondrial Ca(2+) occurred during maximal extracellular ATP accumulation suggests a link between these cellular rhythms. Inhibition of the mitochondrial Ca(2+) uniporter disrupted the rhythmic production and extracellular accumulation of ATP. ATP, calcium, and the biological clock affect cell division and have been implicated in cell death processes. Nonetheless, rhythmic extracellular ATP accumulation was not disrupted by cell cycle arrest and was not correlated with caspase activity in SCN2.2 cell cultures. Together, these results demonstrate that mitochondrial Ca(2+) mediates SCN2.2 rhythms in extracellular ATP accumulation and suggest a role for circadian gliotransmission in SCN clock function.

  3. Native copper as a natural analogue for copper canisters

    International Nuclear Information System (INIS)

    Marcos, N.

    1989-12-01

    This paper discusses the occurrence of native copper as found in geological formations as a stability analogue of copper canisters that are planned to be used for the disposal of spent nuclear fuel in the Finnish bedrock. A summary of several publications on native copper occurrences is presented. The present geochemical and geohydrological conditions in which copper is met with in its metallic state show that metallic copper is stable in a wide range of temperatures. At low temperatures native copper is found to be stable where groundwater has moderate pH (about 7), low Eh (< +100 mV), and low total dissolved solids, especially chloride. Microscopical and microanalytical studies were carried out on a dozen of rock samples containing native copper. The results reveal that the metal shows no significant alteration. Only the surface of copper grains is locally coated. In the oldest samples there exist small corrosion cracks; the age of the oldest samples is over 1,000 million years. A review of several Finnish groundwater studies suggests that there are places in Finland where the geohydrological conditions are favourable for native copper stability. (orig.)

  4. Chimpanzee accumulative stone throwing

    Science.gov (United States)

    Kühl, Hjalmar S.; Kalan, Ammie K.; Arandjelovic, Mimi; Aubert, Floris; D’Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E.; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J.; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M.; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  5. Accumulation by Conservation

    NARCIS (Netherlands)

    Büscher, Bram; Fletcher, Robert

    2015-01-01

    Following the financial crisis and its aftermath, it is clear that the inherent contradictions of capitalist accumulation have become even more intense and plunged the global economy into unprecedented turmoil and urgency. Governments, business leaders and other elite agents are frantically

  6. Accumulation by Conservation

    NARCIS (Netherlands)

    Büscher, Bram; Fletcher, Robert

    2014-01-01

    Following the financial crisis and its aftermath, it is clear that the inherent contradictions of capitalist accumulation have become even more intense and plunged the global economy into unprecedented turmoil and urgency. Governments, business leaders and other elite agents are frantically

  7. Rapid increases in inositol trisphosphate and intracellular Ca++ after heat shock

    International Nuclear Information System (INIS)

    Stevenson, M.A.; Calderwood, S.K.; Hahn, G.M.

    1986-01-01

    Heat shock (45 0 C) caused a rapid ( ++ . In addition to the heat induced rise in intracellular free Ca ++ , an increase in 45 Ca ++ influx was observed following nonlethal heat shock (45 0 C/10 min). The heat-induced increase in 45 Ca ++ influx was linearly related to membrane accumulation of phosphatidic acid, phosphoinositide metabolite that may be involved in Ca ++ gating (1). These results suggest that the membrane may be the proximal target of heat shock

  8. LDL Receptors as Gateways for Intracellular Porphyrin Uptake

    International Nuclear Information System (INIS)

    Novick, S.; Laster, B.; Quastel, M.

    2004-01-01

    Boronated compounds are currently being studied for possible use in Boron Neutron Capture Therapy (BNCT). We found that one of these agents, BOPP (tetrakis-carborane-carboxylate, esters of 2,4-bis (a,b- dihydroxyethyl) deuteroporphyrin IX), could also be labeled with indium (In-BOPP) and, therefore, could also be used potentially to transport high Z atoms into tumor cell DNA for AET (Auger Electron Therapy). In order to assess the uptake of these agents into cells, the role of the LDL receptor in the intracellular accumulation of BOPP and In-BOPP was investigated. Pre-incubation of V-79 Chinese hamster cells in medium containing delipidized fetal bovine serum (FBS) markedly increased the subsequent uptake of intracellular boron transported by both BOPP and In-BOPP when compared with cells that had been pre-incubated with medium containing 10% normal FBS (lipidized). The increased uptake was characterized by elevated levels of receptor, and greater affinity was shown for both BOPP and In-BOPP, although less marked with the latter. Positive cooperativity was demonstrated by sigmoid saturation curves, Scatchard analysis and Hill plots. Increasing the amount of LDL in the incubation medium had a relatively small effect on the total accumulation of either indium or boron atoms inside the cell. Furthermore, chemical acetylation of LDL did not decrease the intracellular uptake of either boron or indium transported by BOPP or In-BOPP. It is thus concluded that BOPP and In-BOPP preferentially enter the cells directly by way of the LDL receptor and that only a small fraction of these molecules are transported into the cells indirectly using serum LDLs as their carriers. These data suggest a novel way of bringing greater amounts of boron and indium (and perhaps other agents) into tissues. Porphyrins can be used to transport different agents into tumor cells because they are tumor affinic molecules. Tumors express a higher number of LDL receptors than do most normal tissues

  9. Bioaccumulation of copper ions by Escherichia coli expressing vanabin genes from the vanadium-rich ascidian Ascidia sydneiensis samea.

    Science.gov (United States)

    Ueki, Tatsuya; Sakamoto, Yasuhisa; Yamaguchi, Nobuo; Michibata, Hitoshi

    2003-11-01

    The genes encoding two vanadium-binding proteins, vanabin1 and vanabin2, from a vanadium-rich ascidian, Ascidia sydneiensis samea, were recently identified and cloned (T. Ueki, T. Adachi, S. Kawano, M. Aoshima, N. Yamaguchi, K. Kanamori, and H. Michibata, Biochim. Biophys. Acta 1626:43-50, 2003). The vanabins were found to bind vanadium(IV), and an excess of copper(II) ions inhibited the binding of vanadium(IV) to the vanabins in vitro. In this study, we constructed Escherichia coli strains that expressed vanabin1 or vanabin2 fused to maltose-binding protein (MBP) in the periplasmic space. We found that both strains accumulated about twenty times more copper(II) ions than the control BL21 strain, while no significant accumulation of vanadium was observed. The strains expressing either MBP-vanabin1 or MBP-vanabin2 absorbed approximately 70% of the copper ions in the medium to which 10 micro M copper (II) ions were initially added. The MBP-vanabin1 and MBP-vanabin2 protein expressed in the periplasm bound to copper ions at a copper:protein molar ratio of 8:1 and 5:1, respectively, but MBP did not bind to copper ions. These data showed that the metal-binding proteins vanabin1 and vanabin2 bound copper ions directly and enhanced the bioaccumulation of copper ions by E. coli.

  10. Intracellular transport: from physics to ... biology.

    Science.gov (United States)

    Roux, Aurélien; Cuvelier, Damien; Bassereau, Patricia; Goud, Bruno

    2008-03-01

    Considerable effort over the past three decades has allowed the identification of the protein families that control the cellular machinery responsible for intracellular transport within eukaryotic cells. These proteins are estimated to represent about 10-20% of the human "proteome." The complexity of intracellular transport makes useful the development of model membranes. We describe here experimental systems based on lipid giant unilamellar vesicles (GUVs), which are attached to kinesin molecules. These systems give rise to thin membrane tubes and to complex tubular networks when incubated in vitro with microtubules and ATP. This type of assay, which mimics key events occurring during intracellular transport, allows physicists and biologists to understand how the unique mechanical properties of lipid membranes could be involved in the budding process, the sorting of cargo proteins and lipids, and the separation of the buds from a donor membrane.

  11. Micro- and nanotechnologies for intracellular delivery.

    Science.gov (United States)

    Yan, Li; Zhang, Jinfeng; Lee, Chun-Sing; Chen, Xianfeng

    2014-11-01

    The majority of drugs and biomolecules need to be delivered into cells to be effective. However, the cell membranes, a biological barrier, strictly resist drugs or biomolecules entering cells, resulting in significantly reduced intracellular delivery efficiency. To overcome this barrier, a variety of intracellular delivery approaches including chemical and physical ways have been developed in recent years. In this review, the focus is on summarizing the nanomaterial routes involved in making use of a collection of receptors for the targeted delivery of drugs and biomolecules and the physical ways of applying micro- and nanotechnologies for high-throughput intracellular delivery. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Fluorescent nanothermometers for intracellular thermal sensing.

    Science.gov (United States)

    Jaque, Daniel; Rosal, Blanca Del; Rodríguez, Emma Martín; Maestro, Laura Martínez; Haro-González, Patricia; Solé, José García

    2014-05-01

    The importance of high-resolution intracellular thermal sensing and imaging in the field of modern biomedicine has boosted the development of novel nanosized fluorescent systems (fluorescent nanothermometers) as the next generation of probes for intracellular thermal sensing and imaging. This thermal mapping requires fluorescent nanothermometers with good biocompatibility and high thermal sensitivity in order to obtain submicrometric and subdegree spatial and thermal resolutions, respectively. This review describes the different nanosized systems used up to now for intracellular thermal sensing and imaging. We also include the later advances in molecular systems based on fluorescent proteins for thermal mapping. A critical overview of the state of the art and the future perspective is also included.

  13. How historical copper contamination affects soil structure and mobilization and transport of colloids

    DEFF Research Database (Denmark)

    Paradelo, Marcos; Møldrup, Per; Holmstrup, Martin

    Copper is accumulated in soils due to human activities such as mining industry, agriculture practises, or waste deposals. High concentrations of copper can affect plants and soil organisms, and subsequently the soil structure and its inner space architecture. In this work we investigated the effect...... between 0.01 to 0.43 pore volumes, with longer times for the most contaminated point, likely related with its higher soil density and lower air permeability. The copper pollution affected colloid and tracer transport in the soil columns. The release of colloids especially in the most contaminated points...

  14. Copper transporters and the cellular pharmacology of the platinum-containing cancer drugs.

    Science.gov (United States)

    Howell, Stephen B; Safaei, Roohangiz; Larson, Christopher A; Sailor, Michael J

    2010-06-01

    Multiple lines of evidence indicate that the platinum-containing cancer drugs enter cells, are distributed to various subcellular compartments, and are exported from cells via transporters that evolved to manage copper homeostasis. The cytotoxicity of the platinum drugs is directly related to how much drug enters the cell, and almost all cells that have acquired resistance to the platinum drugs exhibit reduced drug accumulation. The major copper influx transporter, copper transporter 1 (CTR1), has now been shown to control the tumor cell accumulation and cytotoxic effect of cisplatin, carboplatin, and oxaliplatin. There is a good correlation between change in CTR1 expression and acquired cisplatin resistance among ovarian cancer cell lines, and genetic knockout of CTR1 renders cells resistant to cisplatin in vivo. The expression of CTR1 is regulated at the transcriptional level by copper via Sp1 and at the post-translational level by the proteosome. Copper and cisplatin both trigger the down-regulation of CTR1 via a process that involves ubiquitination and proteosomal degradation and requires the copper chaperone antioxidant protein 1 (ATOX1). The cisplatin-induced degradation of CTR1 can be blocked with the proteosome inhibitor bortezomib, and this increases the cellular uptake and the cytotoxicity of cisplatin in a synergistic manner. Copper and platinum(II) have similar sulfur binding characteristics, and the presence of stacked rings of methionines and cysteines in the CTR1 trimer suggest a mechanism by which CTR1 selectively transports copper and the platinum-containing drugs via sequential transchelation reactions similar to the manner in which copper is passed from ATOX1 to the copper efflux transporters.

  15. Role of copper in photochemical damage to hair.

    Science.gov (United States)

    Marsh, J M; Iveson, R; Flagler, M J; Davis, M G; Newland, A B; Greis, K D; Sun, Y; Chaudhary, T; Aistrup, E R

    2014-02-01

    The objective of this work was to identify whether low levels of redox metals such as copper will accelerate damage to hair on exposure to UV irradiation and whether this damage can be prevented. The methods used were proteomics to measure the protein damage via protein loss after different periods of exposure and mass spectroscopy methods to identify specific marker peptides that are specifically created by this type of damage. In this work, we have developed new insights into the mechanism of UV damage using these proteomic methods. A marker fragment in the hair protein loss extract was identified (m/z = 1279) that is unique to UV exposure and increases with time of UV exposure. We have also identified for the first time in hair the role of exogenous copper in increasing UV damage both in terms of total protein degradation and also increased formation of the marker fragment and proposed a mechanism of action. It has been demonstrated that shampoo treatment containing a chelant such as N,N'-ethylenediamine disuccinic acid (EDDS) reduced copper accumulation in hair. This work provides evidence for the role of copper in UV-induced damage to hair and strategies to reduce copper levels in hair using a chelant such as EDDS. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  16. Copper influence on bank vole's (Myodes glareolus) sexual behavior.

    Science.gov (United States)

    Miska-Schramm, Agata; Kapusta, Joanna; Kruczek, Małgorzata

    2018-04-01

    The impact of human activity on the environment has led to a steady increase of the amounts of copper in the ecosystems. This element accumulates in plants and water, potentially exposing rodents to its harmful effects. In industrial districts, a decrease in the density of small rodent populations has been observed. This decline may be caused by many factors, including mortality, decreased fertility, or impaired sexual behavior. The decline in the reproductive abilities of small rodents after copper exposure was demonstrated in our previous work (Miska-Schramm A, Kruczek M, Kapusta J, Ecotoxicology 23:1546-1554, 2014). The aim of the presented research was to determine how copper administered at concentrations similar to those recorded in industrial districts (Cu I-150 mg/kg, Cu II-600 mg/kg, C-control) affects the sexual behavior of small rodents. The model species was the bank vole (Myodes glareolus). The behavior and vocalizations of male-female pairs were recorded during open-field tests: ♂C vs. ♀C; ♂Cu I vs. ♀C; ♂Cu II vs. ♀C while in preference tests, female behavior was assessed in the following combinations: ♀C vs. ♂C & ♂Cu I; ♀C vs. ♂C & ♂Cu II. In the presented work, we show that copper decreased the males' sexual attractiveness. Females showed suppressed preference towards males treated with 600 mg/kg copper. The number of sniffs and a number of approaches towards Cu II males was significantly lower than towards control individuals. Also, in preference test with 150 mg/kg treated animals, total activity was lower towards copper treated animals. At the same time, copper did not influence intra-sexual interactions.

  17. Biosorption of lead, copper and cadmium by an indigenous isolate Enterobacter sp. J1 possessing high heavy-metal resistance

    International Nuclear Information System (INIS)

    Lu, W.-B.; Shi, J.-J.; Wang, C.-H.; Chang, J.-S.

    2006-01-01

    This study was undertaken to investigate biosorption kinetics and equilibria of lead (Pb), copper (Cu) and cadmium (Cd) ions using the biomass of Enterobacter sp. J1 isolated from a local industry wastewater treatment plant. Efficiency of metal ion recovery from metal-loaded biomass to regenerate the biosorbent was also determined. The results show that Enterobacter sp. J1 was able to uptake over 50 mg of Pb per gram of dry cell, while having equilibrium adsorption capacities of 32.5 and 46.2 mg/g dry cell for Cu and Cd, respectively. In general, Langmuir and Freundlich models were able to describe biosorption isotherm fairly well, except that prediction of Pb adsorption was relatively poor with Langmuir model, suggesting a different mechanism for Pb biosorption. Adjusting the pH value to 3.0 led to nearly complete desorption of Cd from metal-loaded biomass, while over 90% recovery of Pb and Cu ions was obtained at pH ≤ 2. After four repeated adsorption/desorption cycles, biomass of Enterobacter sp. J1 retained 75, 79 and 90% of original capacity for adsorption of Pb, Cu and Cd, respectively, suggesting good reusability of the biosorbent. A combinative model was proposed to describe the kinetics of heavy-metal adsorption by Enterobacter sp. J1 and the model appeared to have an excellent prediction of the experimental data. The model simulation results also seemed to suggest that intracellular accumulation may occur during the uptake of Pb

  18. Jet-printed copper metallization

    Science.gov (United States)

    Hong, Cheong Min

    Macroelectronics is a technology for making electronic circuits over very large areas at low cost. Flat panel displays, sensor arrays, and thin film solar cells are examples of macroelectronics. Crucial to the success of this new technology is the development of inexpensive electronic processes, materials, and devices. Direct printing techniques, which eliminate processing steps and save device and process materials, are the key to high volume and high throughput manufacturing. Copper metallization has been receiving increasing attention in both microelectronics and macroelectronics. Copper has high conductivity, density, melting point, heat capacity, and thermal conductivity. However, copper is also hard to dry etch. For these reasons we have developed and demonstrated a directly printed copper source/drain metallization technique and applied it to the fabrication of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFTs). The maximum process temperature of 200°C is compatible with conventional active matrix liquid crystal display (AMLCD) technology. In this dissertation, we show the process of depositing copper films by jet printing. We discuss the preparation and the properties of the copper precursor material used in the jet printing. We survey the conversion process from copper precursor to copper under varying processing conditions. The resulting copper film is probed for its physical, electrical, and mechanical properties. To demonstrate the feasibility of the jet printing technique, we print copper source/drain contacts for a-Si:H TFTs. The photolithography-free TFT fabrication process uses the printed xerographic toner technique developed earlier in this laboratory. We show that functional TFTs can be made with printed copper source and drain contacts. The jet printing of copper contacts represents a further step toward an all-printed thin film transistor technology.

  19. Arylthiazole antibiotics targeting intracellular methicillin-resistant Staphylococcus aureus (MRSA) that interfere with bacterial cell wall synthesis.

    Science.gov (United States)

    Eid, Islam; Elsebaei, Mohamed M; Mohammad, Haroon; Hagras, Mohamed; Peters, Christine E; Hegazy, Youssef A; Cooper, Bruce; Pogliano, Joe; Pogliano, Kit; Abulkhair, Hamada S; Seleem, Mohamed N; Mayhoub, Abdelrahman S

    2017-10-20

    The promising antibacterial potency of arylthiazole antibiotics is offset by their limited activity against intracellular bacteria (namely methicillin-resistant Staphylococcus aureus (MRSA)), similar to many clinically-approved antibiotics. The failure to target these hidden pathogens is due to the compounds' lack of proper characteristics to accumulate intracellularly. Fine tuning of the size and polar-surface-area of the linking heteroaromatic ring provided a new series of 5-thiazolylarylthiazoles with balanced properties that allow them to sufficiently cross and accumulate inside macrophages infected with MRSA. The most promising compound 4i exhibited rapid bactericidal activity, good metabolic stability and produced over 80% reduction of intracellular MRSA in infected macrophages. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Role of intracellular infections in premature childbirth.

    Science.gov (United States)

    Zurabishvili, S; Mamamtavrishvili, I; Apridonidze, K; Shanidze, L

    2005-09-01

    Vaginal Smear taken by sterile Folkman spoon from 15 women with premature birth was studied. The study was performed by the direct immune fluorescence method with the luminescence microscope. We aimed to study the effect of intracellular infections: ureaplasma urealitikum, mycoplasma hominis, Chlamydia trachomatis, herpes simplex virus of I and II type and cytomegalovirus. Intracellular infections were detected in at about 82% of cases, which included mono infections with cytomegalovirus and in 9 cases in the form of bi-component associations. The obtained results may be interesting from the etiologic point of view of premature births in Georgian population.

  1. 1H NMR-based metabolomics investigation of copper-laden rat: a model of Wilson's disease.

    Directory of Open Access Journals (Sweden)

    Jingjing Xu

    Full Text Available Wilson's disease (WD, also known as hepatoleticular degeneration (HLD, is a rare autosomal recessive genetic disorder of copper metabolism, which causes copper to accumulate in body tissues. In this study, rats fed with copper-laden diet are used to render the clinical manifestations of WD, and their copper toxicity-induced organ lesions are studied. To investigate metabolic behaviors of 'decoppering' process, penicillamine (PA was used for treating copper-laden rats as this chelating agent could eliminate excess copper through the urine. To date, there has been limited metabolomics study on WD, while metabolic impacts of copper accumulation and PA administration have yet to be established.A combination of 1HNMR spectroscopy and multivariate statistical analysis was applied to examine the metabolic profiles of the urine and blood serum samples collected from the copper-laden rat model of WD with PA treatment.Copper accumulation in the copper-laden rats is associated with increased lactate, creatinine, valine and leucine, as well as decreased levels of glucose and taurine in the blood serum. There were also significant changes in p-hydroxyphenylacetate (p-HPA, creatinine, alpha-ketoglutarate (α-KG, dimethylamine, N-acetylglutamate (NAG, N-acetylglycoprotein (NAC in the urine of these rats. Notably, the changes in p-HPA, glucose, lactate, taurine, valine, leucine, and NAG were found reversed following PA treatment. Nevertheless, there were no changes for dimethylamine, α-KG, and NAC as a result of the treatment. Compared with the controls, the concentrations of hippurate, formate, alanine, and lactate were changed when PA was applied and this is probably due to its side effect. A tool named SMPDB (Small Molecule Pathway Database is introduced to identify the metabolic pathway influenced by the copper-laden diet.The study has shown the potential application of NMR-based metabolomic analysis in providing further insights into the molecular

  2. Homing in on an intracellular target for delivery of loaded nanoparticles functionalized with a histone deacetylase inhibitor.

    Science.gov (United States)

    Zhang, Jie; Shi, Yaling; Zheng, Yueqin; Pan, Chengcheng; Yang, Xiaoying; Dou, Taoyan; Wang, Binghe; Lu, Wen

    2017-09-15

    Functionalized nanoparticles (NPs) are usually used to enhance cellular penetration for targeted drug delivery that can improve efficacy and reduce side effects. However, it is difficult to exploit intracellular targets for similar delivery applications. Herein we describe the targeted delivery of functionalized NPs by homing in on an intracellular target, histone deacetylases (HDACs). Specifically, a modified poly-lactide-co-glycolideacid (FPLGA) was yielded by conjugation with an HDAC inhibitor. Subsequently, FPLGA was used to prepare functionalized FPLGA NPs. Compared to unmodified NPs, FPLGA NPs were more efficiently uptaken or retained by MCF-7 cells and showed longer retention time intracellular. In vivo fluorescence imaging also revealed that they had a higher accumulation and a slower elimination than unmodified NPs. FPLGA NPs loaded with paclitaxel exhibited superior anticancer efficacy compared with unmodified NPs. These results offer a promising approach for intracellular drug delivery through elevating the concentration of NPs.

  3. Soil and sediment concentrations of chromium, copper, and arsenic adjacent to a chromated copper arsenate-treated wetland boardwalk

    Science.gov (United States)

    Stan Lebow; Daniel Foster

    2010-01-01

    Environmental accumulation of preservative adjacent to a chromated copper arsenate (type C)–treated wetland boardwalk was evaluated. The site is considered a realistic ‘‘worst case’’ because of the large volume of treated wood, low current speeds, high annual rainfall, and environmental sensitivity. Soil and sediment samples were collected before construction and 0.5,...

  4. Accumulation of satellites

    International Nuclear Information System (INIS)

    Safronov, V.S.; Ruskol, E.L.

    1977-01-01

    Formation and evolution of circumplanetary satellite swarms are investigated. Characteristic times of various processes are estimated. The characteristic time for the accumulation of the bodies in the swarm was several orders of magnitude shorter than that of the planet, i.e. than the time of the replenishment of the material by the swarm (10 8 yr). The model of the accumulation of the swarm is constructed taking into account the increase of its mass due to trapping of heliocentrically moving particles and its decrease due to outfall of the inner part of the swarm onto the growing planet. The accumulation of circumplanetary bodies is also considered. The main features of the evolution of the swarm essentially depend on the size distribution of bodies in the swarm and in the zone of the planet and also on the degree of the concentration of the swarm mass toward the planet. If the sum of the exponents of the inverse power laws of these distributions is less than 7, the model of the transparent swarm developed in this paper should be preferred. When this sum is greater than 7, the model of opaque swarm suggested by A. Harris and W.M. Kaula is better. There is predominant trapping of small particles into the swarm due to their more frequent collisions. Optical thickness of the protoplanetary cloud in radial direction is estimated. It is shown that at the final stage of the planetary accumulation, the cloud was semitransparent in the region of terrestrial planets and volatile substances evaporated at collisions could be swept out from the outer parts of the satellite swarm by the solar wind

  5. Nickel, copper and cobalt coalescence in copper cliff converter slag

    Directory of Open Access Journals (Sweden)

    Wolf A.

    2016-01-01

    Full Text Available The aim of this investigation is to assess the effect of various additives on coalescence of nickel, copper and cobalt from slags generated during nickel extraction. The analyzed fluxes were silica and lime while examined reductants were pig iron, ferrosilicon and copper-silicon compound. Slag was settled at the different holding temperatures for various times in conditions that simulated the industrial environment. The newly formed matte and slag were characterized by their chemical composition and morphology. Silica flux generated higher partition coefficients for nickel and copper than the addition of lime. Additives used as reducing agents had higher valuable metal recovery rates and corresponding partition coefficients than fluxes. Microstructural studies showed that slag formed after adding reductants consisted of primarily fayalite, with some minute traces of magnetite as the secondary phase. Addition of 5 wt% of pig iron, ferrosilicon and copper-silicon alloys favored the formation of a metallized matte which increased Cu, Ni and Co recoveries. Addition of copper-silicon alloys with low silicon content was efficient in copper recovery but coalescence of the other metals was low. Slag treated with the ferrosilicon facilitated the highest cobalt recovery while copper-silicon alloys with silicon content above 10 wt% resulted in high coalescence of nickel and copper, 87 % and 72 % respectively.

  6. Spectrographic determination of impurities in copper and copper oxide

    International Nuclear Information System (INIS)

    Sabato, S.F.; Lordello, A.R.

    1990-11-01

    An emission spectrographic method for the determination of Al, Bi, Ca, Cd, Cr, Fe, Ge, Mg, Mn, Mo, Ni, Pb, Sb, Si, Sn and Zn in copper and copper oxide is described. Two mixtures (Graphite and ZnO: graphite and GeO sub(2)) were used as buffers. The standard deviation lies around 10%. (author)

  7. New data on the Hyrkkoelae U-Cu mineralization: the behaviour of native copper in a natural environment

    International Nuclear Information System (INIS)

    Marcos, N.; Ahonen, L.

    1999-05-01

    The Hyrkkoelae Cu-U mineralisation (SW Finland) is studied as an analogue to the behaviour of copper canister in crystalline bedrock. Uranium-native copper and uranium-copper corrosion products interactions are also addressed in this study. The integration of uranium series disequilibrium (USD) studies gives an estimate of the time-scales of the corrosion processes. The mineral assemblages native copper-copper sulfide, copper sulfides - copper iron sulfides, and native copper-copper oxide (cuprite) occur in open fractures at several depth intervals within granite pegmatites (GP). The surfaces of these open fractures have accumulations of uranophane crystals and other unidentified uranyl compounds. The secondary uranium minerals are mainly distributed around copper sulfide grains. Microscopic intergrowths of copper sulfides and uranyl compounds also have been observed. The surface of the fracture where native copper and cuprite occur is covered with uranium-rich smectite. The very low 234 U/ 238 U activity ratio (0.29 - 0.39) in the main uranium fraction in smectite indicates chemical stable conditions (e.g., oxidising) during at least a time period comparable to the half-life of the 234 U isotope (T 1/2 = 2.44 x 10 5 a). Groundwater samples were collected from intervals where copper minerals occur within open fractures. The Eh and pH conditions were measured during long-term pumping (2-4 weeks per sample). Eh was measured both in situ and an the surface using three electrodes (Pt, Au, C). The actual groundwater conditions are oxidising and would not allow the sulfidization of native copper. Sulfidization may be considered as on old phenomenon, older than the precipitation of uranyl phases in the samples. The end of sulfidization may be earlier than the precipitation and/or remobilisation of U(VI) phases in a time span from about 2 x 10 5 years (precipitation of uranophane) to 2.44 x 10 5 (remobilisation of U from smectite). (orig.)

  8. Hepatitis C virus intracellular host interactions

    NARCIS (Netherlands)

    Liefhebber, Johanna Maaike Pieternella

    2010-01-01

    Hepatitis C virus (HCV) infects about 170 million people worldwide causing a major healthcare problem. The virus lifecycle is greatly dependent on the host-cell for effective replication. In this thesis, the intracellular interactions of the non-structural HCV proteins with the host-cell were

  9. Enhanced production of intracellular dextran dextrinase from ...

    African Journals Online (AJOL)

    Enhanced production of intracellular dextran dextrinase from Gluconobacter oxydans using statistical experimental methods. ... the Plackett-Burman screening. A four-factor five-level central composite design (CCD) was chosen to explain the combined effects of the four medium constituents. The optimum medium consisted ...

  10. Biological synthesis and characterization of intracellular gold ...

    Indian Academy of Sciences (India)

    ... nontoxic, safe, biocompatible and environmentally acceptable. In the present study, Aspergillus fumigatus was used for the intracellular synthesis of gold nanoparticles. Stable nanoparticles were produced when an aqueous solution of chloroauric acid (HAuCl4) was reduced by A. fumigatus biomass as the reducing agent ...

  11. Efficient intracellular delivery of native proteins

    NARCIS (Netherlands)

    D'Astolfo, Diego S; Pagliero, Romina J; Pras, Anita; Karthaus, Wouter R; Clevers, Hans; Prasad, Vikram; Lebbink, Robert Jan; Rehmann, Holger; Geijsen, Niels

    2015-01-01

    Modulation of protein function is used to intervene in cellular processes but is often done indirectly by means of introducing DNA or mRNA encoding the effector protein. Thus far, direct intracellular delivery of proteins has remained challenging. We developed a method termed iTOP, for induced

  12. Temporal protein expression pattern in intracellular signalling ...

    Indian Academy of Sciences (India)

    2015-09-28

    Sep 28, 2015 ... [Ganguli P, Chowdhury S, Bhowmick R and Sarkar RR 2015 Temporal protein expression pattern in intracellular signalling cascade during T-cell activation: A ... cells and tissues by studying different signalling pathways, such as Hedgehog ...... Murray JD 2003 On the mechanochemical theory of biological.

  13. Selenium accumulation by plants.

    Science.gov (United States)

    White, Philip J

    2016-02-01

    Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg(-1) dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000-15 000 mg Se kg(-1 )dry matter and are called Se hyperaccumulators. This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops

  14. Optimizing Nanoelectrode Arrays for Scalable Intracellular Electrophysiology.

    Science.gov (United States)

    Abbott, Jeffrey; Ye, Tianyang; Ham, Donhee; Park, Hongkun

    2018-03-20

    Electrode technology for electrophysiology has a long history of innovation, with some decisive steps including the development of the voltage-clamp measurement technique by Hodgkin and Huxley in the 1940s and the invention of the patch clamp electrode by Neher and Sakmann in the 1970s. The high-precision intracellular recording enabled by the patch clamp electrode has since been a gold standard in studying the fundamental cellular processes underlying the electrical activities of neurons and other excitable cells. One logical next step would then be to parallelize these intracellular electrodes, since simultaneous intracellular recording from a large number of cells will benefit the study of complex neuronal networks and will increase the throughput of electrophysiological screening from basic neurobiology laboratories to the pharmaceutical industry. Patch clamp electrodes, however, are not built for parallelization; as for now, only ∼10 patch measurements in parallel are possible. It has long been envisioned that nanoscale electrodes may help meet this challenge. First, nanoscale electrodes were shown to enable intracellular access. Second, because their size scale is within the normal reach of the standard top-down fabrication, the nanoelectrodes can be scaled into a large array for parallelization. Third, such a nanoelectrode array can be monolithically integrated with complementary metal-oxide semiconductor (CMOS) electronics to facilitate the large array operation and the recording of the signals from a massive number of cells. These are some of the central ideas that have motivated the research activity into nanoelectrode electrophysiology, and these past years have seen fruitful developments. This Account aims to synthesize these findings so as to provide a useful reference. Summing up from the recent studies, we will first elucidate the morphology and associated electrical properties of the interface between a nanoelectrode and a cellular membrane

  15. A novel COMMD1 mutation Thr174Met associated with elevated urinary copper and signs of enhanced apoptotic cell death in a Wilson Disease patient

    OpenAIRE

    Gupta, Arnab; Chattopadhyay, Ishita; Mukherjee, Shashwata; Sengupta, Mainak; Das, Shyamal K; Ray, Kunal

    2010-01-01

    Abstract Wilson disease (WD) results from accumulation of copper and caused due to mutations in ATP7B, a copper transporting ATPase. Besides regular hepatic and neurological symptoms, WD patients occasionally manifest atypical symptoms due to unknown cause. To understand the molecular etiology of atypical WD manifestations, we screened COMMD1, a gene implicated in canine copper toxicosis, in 109 WD patients including those with atypical symptoms. In a patient showing apoptotic symptoms and hi...

  16. Studies of copper transport in mammalian cells using copper radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Camakaris, J.; Voskoboinik, I.; Brooks, H.; Greenough, M. [University of Melbourne, Parkville, VIC (Australia). Department of Genetics; Smith, S. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia). Radiopharmaceuticals Division; Mercer, J. [Deakin University, Clayton, VIC (Australia). Centre of Cellular and Molecular Biology

    1998-12-31

    The trace element copper poses a major problem for all organisms. It is essential as a number of vital enzymes require it. Copper deficiency can lead to neurological disorders, osteoporosis and weakening of arteries. However Cu is also highly toxic and homeostatic mechanisms have evolved to maintain Cu at levels which satisfy requirements but do not cause toxicity. Toxicity is mediated by the oxidative capacity of Cu and its ability to generate toxic free radicals. There are several acquired and inherited diseases due to either Cu toxicity or Cu deficiency. The study of these diseases facilitates identification of genes and proteins involved in copper homeostasis, and this in turn will provide rational therapeutic approaches. Using the copper radioisotopes {sup 64}Cu (t1/2 = 12.8 hr) and {sup 67}Cu (t1/2 = 61 hr) we have developed a number of systems for studying copper transport in mammalian cells. These include investigation of copper uptake, copper efflux and ligand blot assays for Cu-binding proteins. Our studies have focused on Menkes disease which is an inherited and usually lethal copper deficiency disorder in humans. We have demonstrated that the Menkes protein is directly involved as a copper efflux pump in mammalian cells. Using cells overexpressing the Menkes protein we have provided the first biochemical evidence that this functions as a Cu translocating (across the membrane) P-type ATPase (Voskoboinik et al., FEBS Letters, in press). These studies were carried out using purified plasma membrane vesicles. We are now carrying out structure- function studies on this protein using targeted mutations and assaying using the radiocopper vesicle assay. Recently we have commenced studies on the role of amyloid precursor protein (APP) in copper transport and relationship of this to Alzheimers disease

  17. Sublethal concentrations of waterborne copper induce cellular stress and cell death in zebrafish embryos and larvae

    Directory of Open Access Journals (Sweden)

    Pedro P Hernandez

    2011-01-01

    Full Text Available Copper is an essential ion that forms part of the active sites of many proteins. At the same time, an excess of this metal produces free radicals that are toxic for cells and organisms. Fish have been used extensively to study the effects of metals, including copper, present in food or the environment. It has been shown that different metals induce different adaptive responses in adult fish. However, until now, scant information has been available about the responses that are induced by waterborne copper during early life stages of fish. Here, acute toxicity tests and LC50 curves have been generated for zebrafish larvae exposed to dissolved copper sulphate at different concentrations and for different treatment times. We determined that the larvae incorporate and accumulate copper present in the medium in a concentration-dependent manner, resulting in changes in gene expression. Using a transgenic fish line that expresses enhanced green fluorescent protein (EGFP under the hsp70 promoter, we monitored tissue-specific stress responses to waterborne copper by following expression of the reporter. Furthermore, TUNEL assays revealed which tissues are more susceptible to cell death after exposure to copper. Our results establish a framework for the analysis of whole-organism management of excess external copper in developing aquatic animals.

  18. Intracellular distribution of nontargeted quantum dots after natural uptake and microinjection

    Science.gov (United States)

    Damalakiene, Leona; Karabanovas, Vitalijus; Bagdonas, Saulius; Valius, Mindaugas; Rotomskis, Ricardas

    2013-01-01

    Background: The purpose of this study was to elucidate the mechanism of natural uptake of nonfunctionalized quantum dots in comparison with microinjected quantum dots by focusing on their time-dependent accumulation and intracellular localization in different cell lines. Methods: The accumulation dynamics of nontargeted CdSe/ZnS carboxyl-coated quantum dots (emission peak 625 nm) was analyzed in NIH3T3, MCF-7, and HepG2 cells by applying the methods of confocal and steady-state fluorescence spectroscopy. Intracellular colocalization of the quantum dots was investigated by staining with Lysotracker®. Results: The uptake of quantum dots into cells was dramatically reduced at a low temperature (4°C), indicating that the process is energy-dependent. The uptake kinetics and imaging of intracellular localization of quantum dots revealed three accumulation stages of carboxyl-coated quantum dots at 37°C, ie, a plateau stage, growth stage, and a saturation stage, which comprised four morphological phases: adherence to the cell membrane; formation of granulated clusters spread throughout the cytoplasm; localization of granulated clusters in the perinuclear region; and formation of multivesicular body-like structures and their redistribution in the cytoplasm. Diverse quantum dots containing intracellular vesicles in the range of approximately 0.5–8 μm in diameter were observed in the cytoplasm, but none were found in the nucleus. Vesicles containing quantum dots formed multivesicular body-like structures in NIH3T3 cells after 24 hours of incubation, which were Lysotracker-negative in serum-free medium and Lysotracker-positive in complete medium. The microinjected quantum dots remained uniformly distributed in the cytosol for at least 24 hours. Conclusion: Natural uptake of quantum dots in cells occurs through three accumulation stages via a mechanism requiring energy. The sharp contrast of the intracellular distribution after microinjection of quantum dots in comparison

  19. Therapeutic Antibodies against Intracellular Tumor Antigens

    Directory of Open Access Journals (Sweden)

    Iva Trenevska

    2017-08-01

    Full Text Available Monoclonal antibodies are among the most clinically effective drugs used to treat cancer. However, their target repertoire is limited as there are relatively few tumor-specific or tumor-associated cell surface or soluble antigens. Intracellular molecules represent nearly half of the human proteome and provide an untapped reservoir of potential therapeutic targets. Antibodies have been developed to target externalized antigens, have also been engineered to enter into cells or may be expressed intracellularly with the aim of binding intracellular antigens. Furthermore, intracellular proteins can be degraded by the proteasome into short, commonly 8–10 amino acid long, peptides that are presented on the cell surface in the context of major histocompatibility complex class I (MHC-I molecules. These tumor-associated peptide–MHC-I complexes can then be targeted by antibodies known as T-cell receptor mimic (TCRm or T-cell receptor (TCR-like antibodies, which recognize epitopes comprising both the peptide and the MHC-I molecule, similar to the recognition of such complexes by the TCR on T cells. Advances in the production of TCRm antibodies have enabled the generation of multiple TCRm antibodies, which have been tested in vitro and in vivo, expanding our understanding of their mechanisms of action and the importance of target epitope selection and expression. This review will summarize multiple approaches to targeting intracellular antigens with therapeutic antibodies, in particular describing the production and characterization of TCRm antibodies, the factors influencing their target identification, their advantages and disadvantages in the context of TCR therapies, and the potential to advance TCRm-based therapies into the clinic.

  20. Copper (II) complexes with aroylhydrazones

    Indian Academy of Sciences (India)

    Copper(II) complexes with aroylhydrazones ... The coordination chemistry of copper(II) with tridentate aroylhydrazones is briefly discussed in this article. ... EPR spectroscopy and variable temperature magnetic susceptibility measurements have been used to reveal the nature of the coordination geometry and magnetic ...

  1. The Bauschinger Effect in Copper

    DEFF Research Database (Denmark)

    Pedersen, Ole Bøcker; Brown, L .M.; Stobbs, W. M.

    1981-01-01

    A study of the Bauschinger effect in pure copper shows that by comparison with dispersion hardened copper the effect is very small and independent of temperature. This suggests that the obstacles to flow are deformable. A simple composite model based on this principle accounts for the data semi...

  2. Competitive reactions among glutathione, cisplatin and copper-phenanthroline complexes.

    Science.gov (United States)

    Cadoni, Enzo; Valletta, Elisa; Caddeo, Graziano; Isaia, Francesco; Cabiddu, Maria Grazia; Vascellari, Sarah; Pivetta, Tiziana

    2017-08-01

    A large number of cancers are treated with cisplatin (CDDP). However, its use is limited by drug resistance, which is often related to intracellular levels of thiol-containing molecules such as glutathione (GSH). The role of GSH in cisplatin-resistant cancer cells is still unclear. GSH may form adducts with CDDP which results in the deactivation of the drug, and, actually, a high intracellular level of GSH was observed in some cisplatin-resistant cancers. To overcome drug resistance, CDDP is often administered in combination with one or more drugs to exploit a possible synergistic effect. In previous studies, we observed that the sensitivity to CDDP of leukemic and ovarian cisplatin-resistant cancer cells was restored in the presence of [Cu(phen) 2 (H 2 O)](ClO 4 ) 2 (C0) (phen is 1,10-phenathroline). In order to clarify the possible interactions between GSH and CDDP, the reactivity and competitive reactions among CDDP, C0 and GSH in binary and ternary mixtures were studied. The investigation was extended also to [Cu(phen)(H 2 O) 2 (ClO 4 ) 2 ] (C10) and GSSG, the oxidized form of GSH. It was observed that CDDP was able to react with the studied copper complexes and with GSH or GSSG. However, in mixtures containing CDDP, GSH or GSSG and C0 or C10, only copper-glutathione complexes were detected, while no platinum-glutathione adducts were found. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Adsorption of copper onto char derived macro alga, Undaria pinnatifida

    International Nuclear Information System (INIS)

    Cho, Hye Jung; Ko, Jeong Huy; Heo, Hyeon Su; Park, Hye Jin; BAe, Yoon Ju; Kim, Jung Hwan; Park, Young-Kwon

    2010-01-01

    Full text: A release of heavy metals into the environment by industrial activities raises much environmental problems because they tend to remain indefinitely, circulating and eventually accumulating throughout the food chain. Copper is essential to human life and health but, like all heavy metals, is potentially toxic as well. The excessive intakes of copper result in its accumulation in the liver and produce gastrointestinal problems, kidney damage, anemia, and continued inhalation of copper-containing sprays is linked with an increase in lung cancer among exposed people. Consequently, we need to eliminate the copper in drinking water. Also, growth rates of marine macro algae far exceed those of terrestrial biomass, without water limitations, so annual primary production rates are higher for the major marine macro algae than for most terrestrial biomass. According to these reasons, we try to use the macro alga, Undaria pinnatifida. Adsorption of heavy metals is one of the possible technologies involved in the removal of toxic metals from industrial waste streams and mining waste water using low-cost adsorbents. In recent years, many low-cost adsorbents such as seaweeds, activated carbon, etc. have been investigated, but the char by macro alga, Undaria pinnatifida, have not proven to be the most effective and promising substrates. The aim of this study is to remove copper from its aqueous solution by Undaria pinnatifida char for various parameters like pH, contact time, and Cu(II) concentration. The adsorption capacity of Cu(II) by Undaria pinnatifida char was investigated as a function of pH, contact time, and Cu(II) concentration at room temperature. And it was verified using equilibrium studies. (author)

  4. Synthesis of cytochrome c oxidase 1 (SCO1) inhibits insulin sensitivity by decreasing copper levels in adipocytes.

    Science.gov (United States)

    Wei, Xiang-Bo; Guo, Liang; Liu, Yang; Zhou, Shui-Rong; Liu, Yuan; Dou, Xin; Du, Shao-Yue; Ding, Meng; Peng, Wan-Qiu; Qian, Shu-Wen; Huang, Hai-Yan; Tang, Qi-Qun

    2017-09-23

    Dysregulation of insulin signaling leads to type 2 diabetes mellitus (T2DM) and other metabolic disorders. Obesity is an important contributor to insulin resistance, and although the understanding of this relationship has improved in recent years, the mechanism of obesity-induced insulin resistance is not completely understood. Disorders of copper metabolism tend to accompany the development of obesity, which increases the risk of insulin resistance. Synthesis of cytochrome c oxidase 1 (SCO1) functions in the assembly of cytochrome c oxidase (COX) and cellular copper homeostasis. However, the role of SCO1 in the regulation of metabolism remains unknown. Here, we found that obese mice had higher expression of SCO1 and lower levels of copper in white adipose tissue (WAT) than did the control mice. Overexpression of SCO1 in adipocytes was associated with copper deficiency. Copper increased insulin sensitivity by decreasing the level of phosphatase and tensin homolog (PTEN) protein. Ectopic expression of SCO1 led to insulin resistance and was accompanied by a decrease in intracellular copper level, and addition of copper abolished the inhibitory effect of SCO1 on insulin sensitivity. Our results demonstrated a novel role of SCO1 in modulating insulin sensitivity via the regulation of copper concentration in WAT and suggested a potential therapeutic target for T2DM. Copyright © 2017. Published by Elsevier Inc.

  5. Curcumin Mitigates the Intracellular Lipid Deposit Induced by Antipsychotics In Vitro.

    Directory of Open Access Journals (Sweden)

    Alberto Canfrán-Duque

    Full Text Available First- and second-generation antipsychotics (FGAs and SGAs, respectively, both inhibit cholesterol biosynthesis and impair the intracellular cholesterol trafficking, leading to lipid accumulation in the late endosome/lysosome compartment. In this study we examined if curcumin, a plant polyphenol that stimulates exosome release, can alleviate antipsychotic-induced intracellular lipid accumulation.HepG2 hepatocarcinoma cells were treated with antipsychotics or placebo and DiI-labelled LDL for 18 h and then exposed to curcumin for the last 2 h. Cells and media were collected separately and used for biochemical analyses, electron microscopy and immunocytochemistry. Exosomes were isolated from the incubation medium by ultracentrifugation.Curcumin treatment reduced the number of heterolysosomes and shifted their subcellular localization to the periphery, as revealed by electron microscopy, and stimulated the release of lysosomal β-hexosaminidase and exosome markers flotillin-2 and CD63 into the media. The presence of DiI in exosomes released by cells preloaded with DiI-LDL demonstrated the endolysosomal origin of the microvesicles. Furthermore, curcumin increased the secretion of cholesterol as well as LDL-derived DiI and [3H]-cholesterol, in association with a decrease of intracellular lipids. Thus, the disruption of lipid trafficking induced by FGAs or SGAs can be relieved by curcumin treatment. This polyphenol, however, did not mitigate the reduction of cholesterol esterification induced by antipsychotics.Curcumin stimulates exosome release to remove cholesterol (and presumably other lipids accumulated within the endolysosomal compartment, thereby normalizing intracellular lipid homeostasis. This action may help minimize the adverse metabolic effects of antipsychotic treatment, which should now be evaluated in clinical trials.

  6. Oral administration of copper to rats leads to increased lymphocyte cellular DNA degradation by dietary polyphenols: implications for a cancer preventive mechanism.

    Science.gov (United States)

    Khan, Husain Y; Zubair, Haseeb; Ullah, Mohd F; Ahmad, Aamir; Hadi, Sheikh M

    2011-12-01

    To account for the observed anticancer properties of plant polyphenols, we have earlier proposed a mechanism which involves the mobilization of endogenous copper ions by polyphenols leading to the generation of reactive oxygen species (ROS) that serve as proximal DNA cleaving agents and lead to cell death. Over the last decade we have proceeded to validate our hypothesis with considerable success. As a further confirmation of our hypothesis, in this paper we first show that oral administration of copper to rats leads to elevated copper levels in lymphocytes. When such lymphocytes with a copper overload were isolated and treated with polyphenols EGCG, genistein and resveratrol, an increased level of DNA breakage was observed. Further, preincubation of lymphocytes having elevated copper levels with the membrane permeable copper chelator neocuproine, resulted in inhibition of polyphenol induced DNA degradation. However, membrane impermeable chelator of copper bathocuproine, as well as iron and zinc chelators were ineffective in causing such inhibition in DNA breakage, confirming the involvement of endogenous copper in polyphenol induced cellular DNA degradation. It is well established that serum and tissue concentrations of copper are greatly increased in various malignancies. In view of this fact, the present results further confirm our earlier findings and strengthen our hypothesis that an important anticancer mechanism of plant polyphenols could be the mobilization of intracellular copper leading to ROS-mediated cellular DNA breakage. In this context, it may be noted that cancer cells are under considerable oxidative stress and increasing such stress to cytotoxic levels could be a successful anticancer approach.

  7. HvZIP7 mediates zinc accumulation in barley (Hordeum vulgare) at moderately high zinc supply

    DEFF Research Database (Denmark)

    Tiong, Jingwen; Mcdonald, Glenn K.; Genc, Yusuf

    2014-01-01

    in dicots. Overexpression of HvZIP7 in barley plants increased Zn uptake when moderately high concentrations of Zn were supplied. Significantly, there was a specific enhancement of shoot Zn accumulation, with no measurable increase in iron (Fe), manganese (Mn), copper (Cu) or cadmium (Cd). HvZIP7 displays...

  8. Molecular genetics and transport analysis of the copper-resistance determinant (pco) from Escherichia coli plasmid pRJ1004.

    Science.gov (United States)

    Brown, N L; Barrett, S R; Camakaris, J; Lee, B T; Rouch, D A

    1995-09-01

    The copper-resistance determinant (pco) of Escherichia coli plasmid pRJ1004 was cloned and sequenced. Tn1000 transposon mutagenesis identified four complementation groups, mutations in any of which eliminated copper resistance. DNA sequence analysis showed that the four complementation groups contained six open reading frames, designated pco-ABCDRS. The protein product sequences derived from the nucleotide sequence show close homology between this copper-resistance system and the cop system of a plasmid pPT23D of Pseudomonas syringae pv. tomato. The PcoR and PcoS protein sequences show homology to the family of two-component sensor/responder phosphokinase regulatory systems. A seventh reading frame (pcoE) was identified from DNA sequence data, and lies downstream of a copper-regulated promoter. Transport assays with 64Cu(II) showed that the resistant cells containing the plasmid had reduced copper accumulation during the log phase of growth, while increased accumulation had previously been observed during stationary phase. Chromosomal mutants defective in cellular copper management were obtained and characterized. In two of these mutants pco resistance was rendered totally inactive, whilst in another two mutants pco complemented the defective genes. These data indicate that plasmid-borne copper resistance in E. coli is linked with chromosomal systems for copper management.

  9. Ice slurry accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, K.G.; Kauffeld, M.

    1998-06-01

    More and more refrigeration systems are designed with secondary loops, thus reducing the refrigerant charge of the primary refrigeration plant. In order not to increase energy consumption by introducing a secondary refrigerant, alternatives to the well established single phase coolants (brines) and different concepts of the cooling plant have to be evaluated. Combining the use of ice-slurry - mixture of water, a freezing point depressing agent (antifreeze) and ice particles - as melting secondary refrigerant and the use of a cool storage makes it possible to build plants with secondary loops without increasing the energy consumption and investment. At the same time the operating costs can be kept at a lower level. The accumulation of ice-slurry is compared with other and more traditional storage systems. The method is evaluated and the potential in different applications is estimated. Aspects of practically use of ice-slurry has been examined in the laboratory at the Danish Technological Institute (DTI). This paper will include the final conclusions from this work concerning tank construction, agitator system, inlet, outlet and control. The work at DTI indicates that in some applications systems with ice-slurry and accumulation tanks have a great future. These applications are described by a varying load profile and a process temperature suiting the temperature of ice-slurry (-3 - -8/deg. C). (au)

  10. Heat exchanger-accumulator

    Science.gov (United States)

    Ecker, Amir L.

    1980-01-01

    What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

  11. Reduction of intracellular glutathione content and radiosensitivity

    International Nuclear Information System (INIS)

    Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

    1986-01-01

    The intracellular glutathione (GSH) content of HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulphoximine or diethyl maleate (DEM). Clonogenicity, single-strand DNA breaks (ssb) and double-strand DNA breaks (dsb) were used as criteria for radiation-induced damage after X- or γ-irradiation. In survival experiments, DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the o.e.r. was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (author)

  12. Reduction of intracellular glutathione content and radiosensitivity

    International Nuclear Information System (INIS)

    Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

    1986-05-01

    The intracellular glutathione (GSH) content in HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulfoximine (BSO) or diethyl maleate (DEM). Clonogenicity, single strand DNA breaks (ssb) and double strand DNA breaks (dsb) were used as criteria for radiation induced damage after X- or γ irradiation. In survival experiments DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the OER was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (Auth.)

  13. Intracellular Protein Delivery for Treating Breast Cancer

    Science.gov (United States)

    2014-08-01

    Intracellular delivery of such proteins, including human tumor suppressors (such as p53) (Brown et al., 2009) and exogenous tumor-killing proteins...vivo systems. Nature materials 11, 1038-1043. Chorny, M., Hood, E., Levy, R.J., and Muzykantov, V.R. (2010). Endothelial delivery of antioxidant ...for the ntracellular delivery of such proteins, including human umor suppressors [7] and exogenous tumor-killing proteins 8—10]), is attractive as a

  14. Fluorescent nanoparticles for intracellular sensing: A review

    International Nuclear Information System (INIS)

    Ruedas-Rama, Maria J.; Walters, Jamie D.; Orte, Angel; Hall, Elizabeth A.H.

    2012-01-01

    Highlights: ► Analytical applications of fluorescent nanoparticles (NPs) in intracellular sensing. ► Critical review on performance of QDots, metal NPs, silica NPs, and polymer NPs. ► Highlighted potential of fluorescence lifetime imaging microscopy (FLIM). - Abstract: Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.

  15. Fluorescent nanoparticles for intracellular sensing: A review

    Energy Technology Data Exchange (ETDEWEB)

    Ruedas-Rama, Maria J., E-mail: mjruedas@ugr.esmailto [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Walters, Jamie D. [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, UK CB2 1QT (United Kingdom); Orte, Angel [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Hall, Elizabeth A.H., E-mail: lisa.hall@biotech.cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT (United Kingdom)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer Analytical applications of fluorescent nanoparticles (NPs) in intracellular sensing. Black-Right-Pointing-Pointer Critical review on performance of QDots, metal NPs, silica NPs, and polymer NPs. Black-Right-Pointing-Pointer Highlighted potential of fluorescence lifetime imaging microscopy (FLIM). - Abstract: Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.

  16. A bacteriophage endolysin that eliminates intracellular streptococci.

    Science.gov (United States)

    Shen, Yang; Barros, Marilia; Vennemann, Tarek; Gallagher, D Travis; Yin, Yizhou; Linden, Sara B; Heselpoth, Ryan D; Spencer, Dennis J; Donovan, David M; Moult, John; Fischetti, Vincent A; Heinrich, Frank; Lösche, Mathias; Nelson, Daniel C

    2016-03-15

    PlyC, a bacteriophage-encoded endolysin, lyses Streptococcus pyogenes (Spy) on contact. Here, we demonstrate that PlyC is a potent agent for controlling intracellular Spy that often underlies refractory infections. We show that the PlyC holoenzyme, mediated by its PlyCB subunit, crosses epithelial cell membranes and clears intracellular Spy in a dose-dependent manner. Quantitative studies using model membranes establish that PlyCB interacts strongly with phosphatidylserine (PS), whereas its interaction with other lipids is weak, suggesting specificity for PS as its cellular receptor. Neutron reflection further substantiates that PlyC penetrates bilayers above a PS threshold concentration. Crystallography and docking studies identify key residues that mediate PlyCB-PS interactions, which are validated by site-directed mutagenesis. This is the first report that a native endolysin can traverse epithelial membranes, thus substantiating the potential of PlyC as an antimicrobial for Spy in the extracellular and intracellular milieu and as a scaffold for engineering other functionalities.

  17. Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

    NARCIS (Netherlands)

    Berg, G.J. van den; Goeij, J.J.M. de; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendruiks, H.F.J.

    1991-01-01

    Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (< 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

  18. Targeted inactivation of copper transporter Atp7b in hepatocytes causes liver steatosis and obesity in mice.

    Science.gov (United States)

    Muchenditsi, Abigael; Yang, Haojun; Hamilton, James P; Koganti, Lahari; Housseau, Franck; Aronov, Lisa; Fan, Hongni; Pierson, Hannah; Bhattacharjee, Ashima; Murphy, Robert; Sears, Cynthia; Potter, James; Wooton-Kee, Clavia R; Lutsenko, Svetlana

    2017-07-01

    Copper-transporting ATPase 2 (ATP7B) is essential for mammalian copper homeostasis. Mutations in ATP7B result in copper accumulation, especially in the liver, and cause Wilson disease (WD). The major role of hepatocytes in WD pathology is firmly established. It is less certain whether the excess Cu in hepatocytes is solely responsible for development of WD. To address this issue, we generated a mouse strain for Cre-mediated deletion of Atp7b and inactivated Atp7b selectively in hepatocytes. Atp7b ΔHep mice accumulate copper in the liver, have elevated urinary copper, and lack holoceruloplasmin but show no liver disease for up to 30 wk. Liver inflammation is muted and markedly delayed compared with the age-matched Atp7b -/- null mice, which show a strong type1 inflammatory response. Expression of metallothioneins is higher in Atp7b ΔHep livers than in Atp7b -/- mice, suggesting better sequestration of excess copper. Characterization of purified cell populations also revealed that nonparenchymal cells in Atp7b ΔHep liver maintain Atp7b expression, have normal copper balance, and remain largely quiescent. The lack of inflammation unmasked metabolic consequences of copper misbalance in hepatocytes. Atp7b ΔHep animals weigh more than controls and have higher levels of liver triglycerides and 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase. By 45 wk, all animals develop liver steatosis on a regular diet. Thus copper misbalance in hepatocytes dysregulates lipid metabolism, whereas development of inflammatory response in WD may depend on copper status of nonparenchymal cells. The implications of these findings for the cell-targeting WD therapies are discussed. NEW & NOTEWORTHY Targeted inactivation of copper-transporting ATPase 2 (Atp7b) in hepatocytes causes steatosis in the absence of inflammation. Copyright © 2017 the American Physiological Society.

  19. [Role of defective intracellular proteolysis in human degenerative diseases].

    Science.gov (United States)

    Nezelof, Christian

    2012-11-01

    Although intracellular protein synthesis has been studied extensively, protein degradation and disposal, know as proteolysis, has been relatively neglected. Modern studies which led two Nobel prizes (de Duve in 1950 and Herschko, Rose and Ciechanover in 1980) established that proteolysis is ensured by two separate but complementary mechanisms: lysosomes responsible for auto and heterophagy and the Ubiquitin-Proteasome System (UPS). The UPS involves ubiquitin, a small molecule consisting of 76 amino acids found in all eukaryotic cells that ensures the identification of the protein to be degraded and its transport to the proteasome, an intracellular complex with enzymes which degrade unneeded or damaged proteins. The proteasome, acting as a composting agent, ensures the enzymatic dissociation of the protein. In this degradation process, as infinite screw, ubiquitin, peptides and amino acids are released and made available for a new cycle. Knowledge of the UPS and its related disorders is continually expanding. Concurrent with lysosomes which work in acidic environment, it is currently known that the UPS provides 80% to 90% of the proteolysis of the short-life proteins and ensures, as chaperon-molecules, the right conformation and hence the correct function of the proteins. The proteolytic activity generates abnormal residues (tau protein, amyloid and related proteins) and various soluble and insoluble wastes. Some are precipitated as inclusion-bodies or aggregosomes, identified years ago by pathologists. These aggregosomes affect almost exclusively long-lived cells (nervous and muscular, macophages). Pigment deposits, such as lipofuscines made by the peroxydation of cell membranes, are the most abundant. Due to their diverse chemical composition, they cannot be empoyed for a scientific classification. Failures of these systems are numerous. They vary not according to the chemical nature of the abnormal protein and wastes but the life span of the targeted cells and

  20. The aeolian dust accumulation curve

    NARCIS (Netherlands)

    Goossens, D.

    2001-01-01

    This article presents a simple physical concept of aeolian dust accumulation, based on the behaviour of the subprocesses of dust deposition and dust erosion. The concept is tested in an aeolian dust wind tunnel. The agreement between the accumulation curve predicted by the model and the accumulation

  1. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    Section 06 - 08*) of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A vacuum-tank, two bending magnets (BST06 and BST07 in blue) with a quadrupole (QDN07, in red) in between, another vacuum-tank, a wide quadrupole (QFW08) and a further tank . The tanks are covered with heating tape for bake-out. The tank left of BST06 contained the stack core pickup for stochastic cooling (see 7906193, 7906190, 8005051), the two other tanks served mainly as vacuum chambers in the region where the beam was large. Peter Zettwoch works on BST06. *) see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984)

  2. Solids Accumulation Scouting Studies

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  3. Zinc Pyrithione Inhibits Yeast Growth through Copper Influx and Inactivation of Iron-Sulfur Proteins▿†

    Science.gov (United States)

    Reeder, Nancy L.; Kaplan, Jerry; Xu, Jun; Youngquist, R. Scott; Wallace, Jared; Hu, Ping; Juhlin, Kenton D.; Schwartz, James R.; Grant, Raymond A.; Fieno, Angela; Nemeth, Suzanne; Reichling, Tim; Tiesman, Jay P.; Mills, Tim; Steinke, Mark; Wang, Shuo L.; Saunders, Charles W.

    2011-01-01

    Zinc pyrithione (ZPT) is an antimicrobial material with widespread use in antidandruff shampoos and antifouling paints. Despite decades of commercial use, there is little understanding of its antimicrobial mechanism of action. We used a combination of genome-wide approaches (yeast deletion mutants and microarrays) and traditional methods (gene constructs and atomic emission) to characterize the activity of ZPT against a model yeast, Saccharomyces cerevisiae. ZPT acts through an increase in cellular copper levels that leads to loss of activity of iron-sulfur cluster-containing proteins. ZPT was also found to mediate growth inhibition through an increase in copper in the scalp fungus Malassezia globosa. A model is presented in which pyrithione acts as a copper ionophore, enabling copper to enter cells and distribute across intracellular membranes. This is the first report of a metal-ligand complex that inhibits fungal growth by increasing the cellular level of a different metal. PMID:21947398

  4. Copper complexes as 'radiation recovery' agents

    International Nuclear Information System (INIS)

    Sorenson, J.R.J.

    1989-01-01

    Copper and its compounds have been used for their remedial effects since the beginning of recorded history. As early as 3000 BC the Egyptians used copper as an antiseptic for healing wounds and to sterilise drinking water; and later, ca 1550 BC, the Ebers Papyrus reports the use of copper acetate, copper sulphate and pulverised metallic copper for the treatment of eye infections. These historical uses of copper and its compounds are particularly interesting in the light of modern evidence concerning the use of certain copper complexes for the treatment of radiation sickness and more recently as an adjunct to radiotherapy for cancer patients. (author)

  5. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  6. Gallium and copper radiopharmaceutical chemistry

    International Nuclear Information System (INIS)

    Green, M.A.

    1991-01-01

    Gallium and copper radionuclides have a long history of use in nuclear medicine. Table 1 presents the nuclear properties of several gallium and copper isotopes that either are used in the routine practice of clinical nuclear medicine or exhibit particular characteristics that might make them useful in diagnostic or therapeutic medicine. This paper will provide some historic perspective along with an overview of some current research directions in gallium and copper radiopharmaceutical chemistry. A more extensive review of gallium radiopharmaceutical chemistry has recently appeared and can be consulted for a more in-depth treatment of this topic

  7. Cover crops influence soil microorganisms and phytoextraction of copper from a moderately contaminated vineyard.

    Science.gov (United States)

    Mackie, K A; Schmidt, H P; Müller, T; Kandeler, E

    2014-12-01

    We investigated the ability of summer (Avena sativa [oat], Trifolium incarnatum [crimson clover], Chenopodium [goosefoot]) and winter (Vicia villosa [hairy vetch], Secale Cereale L. [Rye], Brassica napus L. partim [rape]) cover crops, including a mixed species treatment, to extract copper from an organic vineyard soil in situ and the microbial communities that may support it. Clover had the highest copper content (14.3mgCukg(-1) DM). However, it was the amount of total biomass production that determined which species was most effective at overall copper removal per hectare. The winter crop rye produced significantly higher amounts of biomass (3532kgDMha(-1)) and, therefore, removed significantly higher amounts of copper (14,920mgCuha(-1)), despite less accumulation of copper in plant shoots. The maximum annual removal rate, a summation of best performing summer and winter crops, would be 0.033kgCuha(-1)y(-1). Due to this low annual extraction efficiency, which is less than the 6kgCuha(-1)y(-1) permitted for application, phytoextraction cannot be recommended as a general method of copper extraction from vineyards. Copper concentration did not influence aboveground or belowground properties, as indicated by sampling at two distances from the grapevine row with different soil copper concentrations. Soil microorganisms may have become tolerant to the copper levels at this site. Microbial biomass and soil enzyme activities (arylsulfatase and phosphatase) were instead driven by seasonal fluxes of resource pools. Gram+ bacteria were associated with high soil moisture, while fungi seemed to be driven by extractable carbon, which was linked to high plant biomass. There was no microbial group associated with the increased phytoextraction of copper. Moreover, treatment did not influence the abundance, activity or community structure of soil microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Toxicity of copper and zinc to Puntius parrah (Day, 1865).

    Science.gov (United States)

    Ciji, P P; Bijoy Nandan, S

    2014-02-01

    The toxicities of the trace metals copper and zinc on the fish Puntius parrah were assessed based on standard renewal bioassay methods, and the 96 h LC50 values for copper and zinc were 0.5 mg/L and 9 mg/L, respectively. The zinc and copper concentrations in water and sediment were high in a highly industrialized area compared with those in non-industrialized zones of the Periyar River. The fish exposed to a sublethal concentration of 0.05 mg/L of Cu and 0.9 mg/L of Zn showed a higher accumulation of both of the metals in the liver than in the kidneys, gills, and muscles. The histological changes induced by copper and zinc on the test organism under sublethal concentrations on the 3rd, 7th, 14th, and 28th -days of exposure were also studied. There was a significant decrease (p management strategies need to be developed and implemented to protect water bodies and aquatic organisms from trace metal pollution and its toxic effects. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Evolution of patinas on copper exposed in a suburban area

    International Nuclear Information System (INIS)

    Watanabe, Masamitsu; Toyoda, Etsuko; Handa, Takao; Ichino, Toshihiro; Kuwaki, Nobuo; Higashi, Yasuhiro; Tanaka, Tohru

    2007-01-01

    Copper plates were exposed under sheltered outdoor conditions for up to one year, starting in September 2001 in Musashino City, Tokyo, a suburban area. Following various periods of exposure, the patinas on the plates were characterized to investigate their evolution by using X-ray fluorescence analysis, X-ray diffraction, field emission scanning electron microscopy, and glow discharge optical emission spectroscopy. The difference in the roles of sulfur and chlorine in the early stages of copper patination were identified by analyzing the depth profiles of these two elements. Sulfur was found on top of the patina as cupric sulfates such as posnjakite (Cu 4 SO 4 (OH) 6 . H 2 O) or brochantite (Cu 4 SO 4 (OH) 6 ). Brochantite appeared only after 12 months of exposure. In contrast, chlorine was found on the surface after only one month of exposure. It gradually penetrated the patina as the exposure period lengthened, forming copper chloride complexes. Chloride ions accumulated at the patina/copper interface, forming nantokite (CuCl), which promoted corrosion

  10. Daily rhythmicity of high affinity copper transport.

    Science.gov (United States)

    Perea-García, Ana; Sanz, Amparo; Moreno, Joaquín; Andrés-Bordería, Amparo; de Andrés, Sonia Mayo; Davis, Amanda M; Huijser, Peter; Davis, Seth J; Peñarrubia, Lola

    2016-01-01

    A differential demand for copper (Cu) of essential cupro-proteins that act within the mitochondrial and chloroplastal electronic transport chains occurs along the daily light/dark cycles. This requires a fine-tuned spatiotemporal regulation of Cu delivery, becoming especially relevant under non-optimal growth conditions. When scarce, Cu is imported through plasma membrane-bound high affinity Cu transporters (COPTs) whose coding genes are transcriptionally induced by the SPL7 transcription factor. Temporal homeostatic mechanisms are evidenced by the presence of multiple light- and clock-responsive regulatory cis elements in the promoters of both SPL7 and its COPT targets. A model is presented here for such temporal regulation that is based on the synchrony between the basal oscillatory pattern of SPL7 and its targets, such as COPT2. Conversely, Cu feeds back to coordinate intracellular Cu availability on the SPL7-dependent regulation of further Cu acquisition. This occurs via regulation at COPT transporters. Moreover, exogenous Cu affects several circadian-clock components, such as the timing of GIGANTEA transcript abundance. Together we propose that there is a dynamic response to Cu that is integrated over diurnal time to maximize metabolic efficiency under challenging conditions.

  11. Use of magnetic nanobeads to study intracellular antigen processing

    Energy Technology Data Exchange (ETDEWEB)

    Perrin-Cocon, Laure A.; Chesne, Serge; Pignot-Paintrand, Isabelle; Marche, Patrice N.; Villiers, Christian L. E-mail: christian.villiers@cea.fr

    2001-07-01

    Magnetic nanobeads were covalently linked to antigens and used as a tool to simultaneously follow their intracellular transport into the cells and specifically purify the intracellular compartments implicated in antigen processing. The protein content of these vesicles was analysed by 2D-electrophoresis. Furthermore, nanobeads allowed intracellular localisation of the antigen in electron and fluorescence microscopy.

  12. Use of magnetic nanobeads to study intracellular antigen processing

    International Nuclear Information System (INIS)

    Perrin-Cocon, Laure A.; Chesne, Serge; Pignot-Paintrand, Isabelle; Marche, Patrice N.; Villiers, Christian L.

    2001-01-01

    Magnetic nanobeads were covalently linked to antigens and used as a tool to simultaneously follow their intracellular transport into the cells and specifically purify the intracellular compartments implicated in antigen processing. The protein content of these vesicles was analysed by 2D-electrophoresis. Furthermore, nanobeads allowed intracellular localisation of the antigen in electron and fluorescence microscopy

  13. Anti fouling effect of two saturated copper coatings applied on carbon steel structures

    International Nuclear Information System (INIS)

    Guiamet, P. S.; Gomez de Saravia, S. G.

    2008-01-01

    Biofouling is the colonization of man-made substrata by sessile organisms. The aim of this paper is to evaluate the performance of two anti fouling saturated copper coating. Bioassays were carried out at a harbor in Argentine (38 degree centigrade 02' S-57 degree centigrade 32'W). during six months, one series of pipes and panels were removed monthly to estimate the recruitment of macro and micro fouling species and immediately replaced by clean ones. Another series was removed from the beginning of exposure to monitor the development of the established community (accumulative pipes and panels along six months). Data obtained from control (without a saturated copper coating) and saturated-copper coated pipes and panels were compared in order to estimate performance of the coating. One of two saturated copper coating demonstrated a good effect anti fouling. (Author) 25 refs

  14. Differential pulse voltammetric determination of metformin using copper-loaded activated charcoal modified electrode.

    Science.gov (United States)

    Gholivand, Mohammad Bagher; Mohammadi-Behzad, Leila

    2013-07-01

    A simple and sensitive carbon paste electrode has been developed for the electrochemical trace determination of metformin (MET). This sensor was designed by Copper(II)-loaded activated charcoal (Cu-AC) in the carbon paste electrode (CPE), which provides remarkably improved sensitivity and selectivity for the electrochemical stripping assay of MET. The drug was accumulated on the surface of the electrode through formation of a coordination complex with copper ions, which enhanced the sensitivity of the method. The effects of various copper(II) salts and oxidation states of copper (within the carbon paste electrode) on MET oxidation behavior were also investigated. The calibration graph was linear over the concentration range of 50 nM to 60 μM MET, and the detection limit was calculated as 9 nM. The proposed electrode was used successfully for MET determination in real matrices. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Yeast CUP1 protects HeLa cells against copper-induced stress

    Energy Technology Data Exchange (ETDEWEB)

    Xie, X.X. [Department of Animal Sciences, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai (China); College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou (China); Ma, Y.F.; Wang, Q.S.; Chen, Z.L.; Liao, R.R.; Pan, Y.C. [Department of Animal Sciences, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai (China)

    2015-06-12

    As an essential trace element, copper can be toxic in mammalian cells when present in excess. Metallothioneins (MTs) are small, cysteine-rich proteins that avidly bind copper and thus play an important role in detoxification. YeastCUP1 is a member of the MT gene family. The aim of this study was to determine whether yeast CUP1 could bind copper effectively and protect cells against copper stress. In this study,CUP1 expression was determined by quantitative real-time PCR, and copper content was detected by inductively coupled plasma mass spectrometry. Production of intracellular reactive oxygen species (ROS) was evaluated using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay. Cellular viability was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the cell cycle distribution of CUP1 was analyzed by fluorescence-activated cell sorting. The data indicated that overexpression of yeast CUP1 in HeLa cells played a protective role against copper-induced stress, leading to increased cellular viability (P<0.05) and decreased ROS production (P<0.05). It was also observed that overexpression of yeast CUP1 reduced the percentage of G1 cells and increased the percentage of S cells, which suggested that it contributed to cell viability. We found that overexpression of yeast CUP1 protected HeLa cells against copper stress. These results offer useful data to elucidate the mechanism of the MT gene on copper metabolism in mammalian cells.

  16. Concentrations of trace metals (lead, iron, copper and zinc) in crops ...

    African Journals Online (AJOL)

    Concentrations of trace metals (lead, iron, copper and zinc) in crops harvested in some oil prospecting locations in Rivers State, Nigeria. ... These findings give cause for concern, particularly as heavy metals are bio-accumulative in the system and portend a serious health risk to man and animals. Key Words: Trace metals, ...

  17. Copper tailings in stucco mortars

    Directory of Open Access Journals (Sweden)

    Osvaldo Pavez

    Full Text Available Abstract This investigation addressed the evaluation of the use of copper tailings in the construction industry in order to reduce the impact on the environment. The evaluation was performed by a technical comparison between stucco mortars prepared with crushed conventional sand and with copper tailings sand. The best results were achieved with the stucco mortars containing tailings. The tailings presented a fine particles size distribution curve different from that suggested by the standard. The values of compressive strength, retentivity, and adherence in the stucco mortars prepared with copper tailings were much higher than those obtained with crushed sand. According to the results from this study, it can be concluded that the preparation of stucco mortars using copper tailings replacing conventional sand is a technically feasible alternative for the construction industry, presenting the benefit of mitigating the impact of disposal to the environment.

  18. Hereditary iron and copper deposition

    DEFF Research Database (Denmark)

    Aaseth, Jan; Flaten, Trond Peder; Andersen, Ole

    2007-01-01

    Hereditary deposition of iron (primary haemochromatosis) or copper (Wilson's disease) are autosomal recessive metabolic disease characterized by progressive liver pathology and subsequent involvement of various other organs. The prevalence of primary haemochromatosis is approximately 0.5%, about...

  19. The Necessity of Having a Tetradentate Ligand to Extract Copper(II) Ions from Amyloids.

    Science.gov (United States)

    Nguyen, Michel; Rechignat, Lionel; Robert, Anne; Meunier, Bernard

    2015-02-01

    The accumulation of redox-active metal ions, in particular copper, in amyloid plaques is considered to the cause of the intensive oxidation damage to the brain of patients with Alzheimers disease (AD). Drug candidates based on a bis(8-aminoquinoline) tetradentate ligand are able to efficiently extract Cu(2+) from copper-loaded amyloids (Cu-Aβ). Contrarily, in the presence of a bidentate hydroxyquinoline, such as clioquinol, the copper is not released from Aβ, but remains sequestrated within a Aβ-Cu-clioquinol ternary complex that has been characterized by mass spectrometry. Facile extraction of copper(II) at a low amyloid/ligand ratio is essential for the re-introduction of copper in regular metal circulation in the brain. As, upon reduction, the Cu(+) is easily released from the bis(8-aminoquinoline) ligand unable to accommodate Cu(I), it should be taken by proteins with an affinity for copper. So, the tetradentate bis(8-aminoquinoline) described here might act as a regulator of copper homeostasis.

  20. Metal accumulation by an epigean and a hypogean freshwater amphipod: Considerations for water quality assessment

    Energy Technology Data Exchange (ETDEWEB)

    Pienet, S.

    1999-12-01

    To evaluate their potential as biomonitors of surface and underground water quality, the accumulation of essential metals, zinc and copper, by two species of amphipod crustaceans, Gammarus fossarum (an epigean amphipod) and Niphargus rhenorhodanensis (a similar but blind and hypogean form) was investigated. These two species were exposed, under controlled laboratory conditions, to different metal concentrations for 12 days. Several concentrations of each of the two metals separately and one concentration of a mixture of both were tested. Percent mortality revealed that the hypogean species was more resistant than the epigean. During the 12 days of experiment, accumulation patterns differed between species and between metals. G. fossarum, but not N. rhenorhodanensis, accumulated zinc at exposures of up to 12 days and concentrations as great as 1,000 {micro}g/L. Zinc levels in tissue of G. fossarum were greater than in those of N. rhenorhodanensis. Epigean and hypogean amphipods did not clearly accumulate copper in exposures as great at 65 {micro}g/L. Possible reasons for the differences in zinc and copper accumulation between the two species are discussed. Finally, the suitability of the two species as biomonitors for surface and underground water is discussed.

  1. Mosses accumulate heavy metals from the substrata of coal ash

    Directory of Open Access Journals (Sweden)

    Vukojević Vanja

    2005-01-01

    Full Text Available Plants that are able to accumulate and tolerate extraordinarily high concentrations of heavy metals (hyperaccumulators can be used for phytoremediation (removal of contaminants from soils or phytomining (growing a crop of plants to harvest the metals. Two moss species, Bryum capillare Hedw. and Ceratodon purpureus Hedw., were tested as potential phytoremedies under in vivo conditions on a coal ash disposal site in the surroundings of Obrenovac (NW Serbia. The content of various heavy metals (iron, manganese zinc, lead, nickel, cadmium, and copper in the mosses and substrata were investigated over a period of three years. Iron and zinc were found to have the highest concentration in the mosses.

  2. TOR (target of rapamycin) is a key regulator of triacylglycerol accumulation in microalgae.

    Science.gov (United States)

    Imamura, Sousuke; Kawase, Yasuko; Kobayashi, Ikki; Shimojima, Mie; Ohta, Hiroyuki; Tanaka, Kan

    2016-01-01

    Most microalgae abundantly accumulate lipid droplets (LDs) containing triacylglycerols (TAGs) under several stress conditions, but the underlying molecular mechanism of this accumulation remains unclear. In a recent study, we found that inhibition of TOR (target of rapamycin), a highly conserved protein kinase of eukaryotes, by rapamycin resulted in TAG accumulation in microalgae, indicating that TOR negatively regulates TAG accumulation. Here, we show that formation of intracellular LDs and TAG accumulation were also induced in the unicellular green alga Chlamydomonas reinhardtii after exposure to Torin1 or AZD8055, which are novel TOR inhibitors that inhibit TOR activity in a manner different from rapamycin. These results supported quite well our previous conclusion that TOR is a central regulator of TAG accumulation in microalgae.

  3. Copper atomic-scale transistors

    Directory of Open Access Journals (Sweden)

    Fangqing Xie

    2017-03-01

    Full Text Available We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO4 + H2SO4 in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate. The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and −170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes (Ubias influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1G0 (G0 = 2e2/h; with e being the electron charge, and h being Planck’s constant or 2G0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

  4. The copper deposits of Michigan

    Science.gov (United States)

    Butler, B.S.; Burbank, W.S.

    1929-01-01

    The copper district of Keweenaw Point, in the northern peninsula of Michigan, is the second largest producer of copper in the world.  The output of the district since 1845 has been more than 7,500,000,000 pounds and showed a rather steady and consistent increase from the beginning of production to the end of the World War in 1918, since which there has been a marked decrease.

  5. Atmospheric corrosion effects on copper

    International Nuclear Information System (INIS)

    Franey, J.P.

    1985-01-01

    Studies have been performed on the naturally formed patina on various copper samples. Samples have been obtained from structures at AT and T Bell Laboratories, Murray Hill, NJ (40,2,1 and <1 yr) and the Statue of Liberty (100 yr). The samples show a distinct layering effect, that is, the copper base material shows separate oxide and basic sulfate layers on all samples, indicating that patina is not a homogeneous mixture of oxides and basic sulfates

  6. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    International Nuclear Information System (INIS)

    Veltman, Karin; Huijbregts, Mark A.J.; Vijver, Martina G.; Peijnenburg, Willie J.G.M.; Hobbelen, Peter H.F.; Koolhaas, Josee E.; Gestel, Cornelis A.M. van; Vliet, Petra C.J. van; Jan Hendriks, A.

    2007-01-01

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slope < 1) related to the total concentration in soil, while risk assessment procedures often assume the biota-soil accumulation factor (BSAF) to be constant. Although predicted internal concentrations of all metals are generally within a factor 5 compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. - Earthworm metal concentrations are less than linearly related to total soil concentrations and predicted pore water concentrations

  7. A Copper-Mediated Disulfiram-Loaded pH-Triggered PEG-Shedding TAT Peptide-Modified Lipid Nanocapsules for Use in Tumor Therapy.

    Science.gov (United States)

    Zhang, Ling; Tian, Bin; Li, Yi; Lei, Tian; Meng, Jia; Yang, Liu; Zhang, Yan; Chen, Fen; Zhang, Haotian; Xu, Hui; Zhang, Yu; Tang, Xing

    2015-11-18

    Disulfiram, which exhibits marked tumor inhibition mediated by copper, was encapsulated in lipid nanocapsules modified with TAT peptide (TATp) and pH-triggered sheddable PEG to target cancer cells on the basis of tumor environmental specificity. PEG-shedding lipid nanocapsules (S-LNCs) were fabricated from LNCs by decorating short PEG chains with TATp (HS-PEG(1k)-TATp) to form TATp-LNCs and then covered by pH-sensitive graft copolymers of long PEG chains (PGA-g-PEG(2k)). The DSF-S-LNCs had sizes in the range of 60-90 nm and were stable in the presence of 50% plasma. DSF-S-LNCs exhibited higher intracellular uptake and antitumor activity at pH 6.5 than at pH 7.4. The preincubation of Cu showed that the DSF cytotoxicity was based on the accumulation of Cu in Hep G2 cells. Pharmacokinetic studies showed the markedly improved pharmacokinetic profiles of DSF-S-LNCs (AUC= 3921.391 μg/L·h, t(1/2z) = 1.294 h) compared with free DSF (AUC = 907.724 μg/L·h, t(1/2z) = 0.252 h). The in vivo distribution of S-LNCs was investigated using Cy5.5 as a fluorescent probe. In tumor-bearing mice, the delivery efficiency of S-LNCs was found to be 496.5% higher than that of free Cy5.5 and 74.5% higher than that of LNCs in tumors. In conclusion, DSF-S-LNCs increased both the stability and tumor internalization and further increased the cytotoxicity because of the higher copper content.

  8. Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

    DEFF Research Database (Denmark)

    Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller

    2014-01-01

    The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances.......The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances....

  9. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    A section of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A large vacuum-tank, a quadrupole (QDN09*), a bending magnet (BST08), another vacuum-tank, a wide quadrupole (QFW08) and (in the background) a further bending magnet (BST08). The tanks are covered with heating tape for bake-out. The tank left of QDN09 contained the kickers for stochastic pre-cooling (see 790621, 8002234, 8002637X), the other one served mainly as vacuum chamber in the region where the beam was large. Peter Zettwoch works on QFW08. * see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984) See under 7911303, 7911597X, 8004261 and 8202324. For photos of the AA in different phases of completion (between 1979 and 1982) see: 7911303, 7911597X, 8004261, 8004608X, 8005563X, 8005565X, 8006716X, 8006722X, 8010939X, 8010941X, 8202324, 8202658X, 8203628X .

  10. Intracellular transport of pancreatic zymogens during caerulein supramaximal stimulation

    International Nuclear Information System (INIS)

    Saito, I.; Hashmimoto, S.; Saluja, A.; Steer, M.L.; Meldolesi, J.

    1987-01-01

    Rats infused with a dose of the secretagogue caerulein that is in excess of that which stimulates a maximal rate of pancreatic digestive enzyme secretion develop acute edematous pancreatitis. The authors have previously noted that infusion of this dose of caerulein induces the appearance of large heterogeneous vacuoles in acinar cell, blockage of exocytosis, and intracellular accumulation of digestive zymogens. The current studies were performed to further elucidate these phenomena at the electron microscopic level of resolution and employed the techniques of pulse labeling, radioautography, and immunolocalization. Rats were infused with caerulein for 1 h, given a pulse of [ 3 H]phenylalanine, and killed at selected times during the subsequent 5- to 180-min postpulse period during which caerulein infusion was continued. Transport from the endoplasmic reticulum to the Golgi cisternae was not altered by supramaximal stimulation, but transport through post-Golgi elements was altered. In particular, the maturation of condensing vacuoles into zymogen granules was found to be impaired. Thus these studies indicate that the large heterogeneous vacuoles that appear during supramaximal secretagogue stimulation and that contain admixed digestive zymogens and lysosomal hydrolases arise by at least two mechanisms, impaired condensing vacuole maturation and crinophagy

  11. Heme requirement and intracellular trafficking in Trypanosoma cruzi epimastigotes

    International Nuclear Information System (INIS)

    Lara, F.A.; Sant'Anna, C.; Lemos, D.; Laranja, G.A.T.; Coelho, M.G.P.; Reis Salles, I.; Michel, A.; Oliveira, P.L.; Cunha-e-Silva, N.; Salmon, D.; Paes, M.C.

    2007-01-01

    Epimastigotes multiplies in the insect midgut by taking up nutrients present in the blood meal including heme bound to hemoglobin of red blood cell. During blood meal digestion by vector proteases in the posterior midgut, hemoglobin is clipped off into amino acids, peptides, and free heme. In this paper, we compared the heme and hemoglobin uptake kinetics and followed their intracellular trafficking. Addition of heme to culture medium increased epimastigote proliferation in a dose-dependent manner, while medium supplemented with hemoglobin enhanced growth after 3-day lag phase. Medium supplemented with globin-derived peptides stimulated cell proliferation in a dose-independent way. Using Palladium mesoporphyrin IX (Pd-mP) as a fluorescent heme-analog, we observed that heme internalization proceeded much faster than that observed by hemoglobin-rhodamine. Binding experiments showed that parasites accumulated the Pd-mP into the posterior region of the cell whereas hemoglobin-rhodamine stained the anterior region. Finally, using different specific inhibitors of ABC transporters we conclude that a P-glycoprotein homologue transporter is probably involved in heme transport through the plasma membrane

  12. Batteries and accumulators in France

    International Nuclear Information System (INIS)

    2012-12-01

    The present report gives an overview of the batteries and accumulators market in France in 2011 based on the data reported through ADEME's Register of Batteries and accumulators. In 2001, the French Environmental Agency, known as ADEME, implemented a follow-up of the batteries and accumulators market, creating the Observatory of batteries and accumulators (B and A). In 2010, ADEME created the National Register of producers of Batteries and Accumulators in the context of the implementation of the order issued on November 18, 2009. This is one of the four enforcement orders for the decree 2009-1139 issued on September 22, 2009, concerning batteries and accumulators put on the market and the disposal of waste batteries and accumulators, and which transposes the EU-Directive 2006/66/CE into French law. This Register follows the former Observatory for batteries and accumulators. This Register aims to record the producers on French territory and to collect the B and A producers and recycling companies' annual reporting: the regulation indeed requires that all B and A producers and recycling companies report annually on the Register the quantities of batteries and accumulators they put on the market, collect and treat. Based on this data analysis, ADEME issues an annual report allowing both the follow-up of the batteries and accumulators market in France and communication regarding the achievement of the collection and recovery objectives set by EU regulation. This booklet presents the situation in France in 2011

  13. Apoplastic and intracellular plant sugars regulate developmental transitions in witches’ broom disease of cacao

    Science.gov (United States)

    Barau, Joan; Grandis, Adriana; Carvalho, Vinicius Miessler de Andrade; Teixeira, Gleidson Silva; Zaparoli, Gustavo Henrique Alcalá; do Rio, Maria Carolina Scatolin; Rincones, Johana; Buckeridge, Marcos Silveira; Pereira, Gonçalo Amarante Guimarães

    2015-01-01

    Witches’ broom disease (WBD) of cacao differs from other typical hemibiotrophic plant diseases by its unusually long biotrophic phase. Plant carbon sources have been proposed to regulate WBD developmental transitions; however, nothing is known about their availability at the plant–fungus interface, the apoplastic fluid of cacao. Data are provided supporting a role for the dynamics of soluble carbon in the apoplastic fluid in prompting the end of the biotrophic phase of infection. Carbon depletion and the consequent fungal sensing of starvation were identified as key signalling factors at the apoplast. MpNEP2, a fungal effector of host necrosis, was found to be up-regulated in an autophagic-like response to carbon starvation in vitro. In addition, the in vivo artificial manipulation of carbon availability in the apoplastic fluid considerably modulated both its expression and plant necrosis rate. Strikingly, infected cacao tissues accumulated intracellular hexoses, and showed stunted photosynthesis and the up-regulation of senescence markers immediately prior to the transition to the necrotrophic phase. These opposite findings of carbon depletion and accumulation in different host cell compartments are discussed within the frame of WBD development. A model is suggested to explain phase transition as a synergic outcome of fungal-related factors released upon sensing of extracellular carbon starvation, and an early senescence of infected tissues probably triggered by intracellular sugar accumulation. PMID:25540440

  14. Apoplastic and intracellular plant sugars regulate developmental transitions in witches' broom disease of cacao.

    Science.gov (United States)

    Barau, Joan; Grandis, Adriana; Carvalho, Vinicius Miessler de Andrade; Teixeira, Gleidson Silva; Zaparoli, Gustavo Henrique Alcalá; do Rio, Maria Carolina Scatolin; Rincones, Johana; Buckeridge, Marcos Silveira; Pereira, Gonçalo Amarante Guimarães

    2015-03-01

    Witches' broom disease (WBD) of cacao differs from other typical hemibiotrophic plant diseases by its unusually long biotrophic phase. Plant carbon sources have been proposed to regulate WBD developmental transitions; however, nothing is known about their availability at the plant-fungus interface, the apoplastic fluid of cacao. Data are provided supporting a role for the dynamics of soluble carbon in the apoplastic fluid in prompting the end of the biotrophic phase of infection. Carbon depletion and the consequent fungal sensing of starvation were identified as key signalling factors at the apoplast. MpNEP2, a fungal effector of host necrosis, was found to be up-regulated in an autophagic-like response to carbon starvation in vitro. In addition, the in vivo artificial manipulation of carbon availability in the apoplastic fluid considerably modulated both its expression and plant necrosis rate. Strikingly, infected cacao tissues accumulated intracellular hexoses, and showed stunted photosynthesis and the up-regulation of senescence markers immediately prior to the transition to the necrotrophic phase. These opposite findings of carbon depletion and accumulation in different host cell compartments are discussed within the frame of WBD development. A model is suggested to explain phase transition as a synergic outcome of fungal-related factors released upon sensing of extracellular carbon starvation, and an early senescence of infected tissues probably triggered by intracellular sugar accumulation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  15. Field and laboratory evaluation of the influence of copper-diquat on apple snails in southern Florida

    Science.gov (United States)

    Winger, P.V.; Imlay, M.J.; McMillan, W.E.; Martin, T.W.; Takekawa, Jean E.; Johnson, W.W.

    1984-01-01

    The recent decline of apple snail (Pomacea paludosa) populations in canals surrounding Loxahatchee National Wildlife Refuge in southern Florida coincided with the use of copper-diquat for the control of the aquatic weed hydrilla (Hydrilla verticillata). Field and laboratory studies were designed to assess the effects of copper-diquat on apple snails, which are the primary food of the endangered snail kite Rostrhamus sociabilis (formerly known as the Everglade kite). Acute toxicities (96-h LC50 values) of Cutrine-Plus and Komeen (chelated formulations of copper) to immature apple snails were 22 and 24 μg/L, respectively. Diquat was toxic at a concentration of 1,800 μg/L and did not increase the toxicity of copper when the chemicals were used in combination. Evaluation of field samples indicated that copper concentrations were higher in detritus than in water, plants and mud, and that there was a gradient of copper concentration from the canal to the interior, the highest residues being in samples from the canal. Copper associated with detritus (up to 150 μg/g) had no effect on growth or survival of apple snails in field cage and tank studies. Also, field applications of copper-diquat to hydrilla had no effect on survival of caged adult and immature snails. Copper from field applications was rapidly taken out of solution by plants and organic material in the water and subsequently incorporated into the bottom detritus. Although the effects of repeated applications of copper-diquat and high body burdens of copper (accumulated during exposure to herbicidal treatment) on survival and reproduction of apple snails are not known, the information available indicates that treatment of hydrilla with copper-diquat was probably not responsible for the decline in the apple snail population. Application at recommended rates should pose no threat to these snails in the organically rich waters of southern Florida.

  16. X-ray fluorescent microscopy reveals large-scale relocalization and extracellular translocation of cellular copper during angiogenesis

    International Nuclear Information System (INIS)

    Finney, L.; Mandava, S.; Ursos, L.; Zhang, W.; Rodi, D.; Vogt, S.; Legnini, D.; Maser, J.; Ikpatt, F.; Olopade, O. I.; Glesne, D.

    2007-01-01

    Although copper has been reported to influence numerous proteins known to be important for angiogenesis, the enhanced sensitivity of this developmental process to copper bioavailability has remained an enigma, because copper metalloproteins are prevalent and essential throughout all cells. Recent developments in x-ray optics at third-generation synchrotron sources have provided a resource for highly sensitive visualization and quantitation of metalloproteins in biological samples. Here, we report the application of x-ray fluorescence microscopy (XFM) to in vitro models of angiogenesis and neurogenesis, revealing a surprisingly dramatic spatial relocalization specific to capillary formation of 80-90% of endogenous cellular copper stores from intracellular compartments to the tips of nascent endothelial cell filopodia and across the cell membrane. Although copper chelation had no effect on process formation, an almost complete ablation of network formation was observed. XFM of highly vascularized ductal carcinomas showed copper clustering in putative neoangiogenic areas. This use of XFM for the study of a dynamic developmental process not only sheds light on the copper requirement for endothelial tube formation but highlights the value of synchrotron-based facilities in biological research

  17. Copper Sensing Function of Drosophila Metal-Responsive Transcription Factor-1 Is Mediated By a Tetranuclear Cu(I) Cluster

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X.; Hua, H.; Balamurugan, K.; Kong, X.; Zhang, L.; George, G.N.; Georgiev, O.; Schaffner, W.; Giedroc, D.P.

    2009-05-12

    Drosophila melanogaster MTF-1 (dMTF-1) is a copper-responsive transcriptional activator that mediates resistance to Cu, as well as Zn and Cd. Here, we characterize a novel cysteine-rich domain which is crucial for sensing excess intracellular copper by dMTF-1. Transgenic flies expressing mutant dMTF-1 containing alanine substitutions of two, four or six cysteine residues within the sequence {sup 547}CNCTNCKCDQTKSCHGGDC{sup 565} are significantly or completely impaired in their ability to protect flies from copper toxicity and fail to up-regulate MtnA (metallothionein) expression in response to excess Cu. In contrast, these flies exhibit wild-type survival in response to copper deprivation thus revealing that the cysteine cluster domain is required only for sensing Cu load by dMTF-1. Parallel studies show that the isolated cysteine cluster domain is required to protect a copper-sensitive S. cerevisiae ace1 strain from copper toxicity. Cu(I) ligation by a Cys-rich domain peptide fragment drives the cooperative assembly of a polydentate [Cu{sub 4}-S{sub 6}] cage structure, characterized by a core of trigonally S{sub 3} coordinated Cu(I) ions bound by bridging thiolate ligands. While reminiscent of Cu{sub 4}-L{sub 6} (L = ligand) tetranuclear clusters in copper regulatory transcription factors of yeast, the absence of significant sequence homology is consistent with convergent evolution of a sensing strategy particularly well suited for Cu(I).

  18. Use of copper radioisotopes in investigating disorders of copper metabolism

    International Nuclear Information System (INIS)

    Camakaris, J.; Voskoboinik, I.; Brooks, H.; Greenough, M.; Smith, S.; Mercer, J.

    1998-01-01

    Full text: Copper is an essential trace element for life as a number of vital enzymes require it. Copper deficiency can lead to neurological disorders, osteoporosis and weakening of arteries. However Cu is also highly toxic and homeostatic mechanisms have evolved to maintain Cu at levels which satisfy requirements but do not cause toxicity. Toxicity is mediated by the oxidative capacity of Cu and its ability to generate toxic free radicals. There are several acquired and inherited diseases due to either Cu toxicity or Cu deficiency. The study of these diseases facilitates identification of genes and proteins involved in copper homeostasis, and this in turn will provide rational therapeutic approaches. Our studies have focused on Menkes disease in humans which is an inherited and usually lethal copper deficiency. Using copper radioisotopes 64 Cu (t 1/2 = 12.8 hr) and 67 Cu (t 1/2 = 61 hr) we have studied the protein which is mutated in Menkes disease. This is a transmembrane copper pump which is responsible for absorption of copper into the body and also functions to pump out excess Cu from cells when Cu is elevated. It is therefore a vital component of normal Cu homeostasis. We have provided the first biochemical evidence that the Menkes protein functions as a P-type ATPase Cu pump (Voskoboinik et al., FEBS Letters, in press) and these data will be discussed. The assay involved pumping of radiocopper into purified membrane vesicles. Furthermore we have transfected normal and mutant Menkes genes into cells and are carrying out structure-function studies. We are also studying the role of amyloid precursor protein (APP) as a Cu transport protein in order to determine how Cu regulates this protein and its cleavage products. These studies will provide vital information on the relationship between Cu and APP and processes which lead to Alzheimers disease

  19. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  20. Effect of Nano-Al2O3 on the Toxicity and Oxidative Stress of Copper towards Scenedesmus obliquus

    Science.gov (United States)

    Li, Xiaomin; Zhou, Suyang; Fan, Wenhong

    2016-01-01

    Nano-Al2O3 has been widely used in various industries; unfortunately, it can be released into the aquatic environment. Although nano-Al2O3 is believed to be of low toxicity, it can interact with other pollutants in water, such as heavy metals. However, the interactions between nano-Al2O3 and heavy metals as well as the effect of nano-Al2O3 on the toxicity of the metals have been rarely investigated. The current study investigated copper toxicity in the presence of nano-Al2O3 towards Scenedesmus obliquus. Superoxide dismutase activity and concentration of glutathione and malondialdehyde in cells were determined in order to quantify oxidative stress in this study. Results showed that the presence of nano-Al2O3 reduced the toxicity of Cu towards S. obliquus. The existence of nano-Al2O3 decreased the growth inhibition of S. obliquus. The accumulation of copper and the level of oxidative stress in algae were reduced in the presence of nano-Al2O3. Furthermore, lower copper accumulation was the main factor that mitigated copper toxicity with the addition of nano-Al2O3. The decreased copper uptake could be attributed to the adsorption of copper onto nanoparticles and the subsequent decrease of available copper in water. PMID:27294942

  1. Effects of silicon and copper on bamboo grown hydroponically.

    Science.gov (United States)

    Collin, Blanche; Doelsch, Emmanuel; Keller, Catherine; Panfili, Frédéric; Meunier, Jean-Dominique

    2013-09-01

    Due to its high growth rate and biomass production, bamboo has recently been proven to be useful in wastewater treatment. Bamboo accumulates high silicon (Si) levels in its tissues, which may improve its development and tolerance to metal toxicity. This study investigates the effect of Si supplementation on bamboo growth and copper (Cu) sensitivity. An 8-month hydroponic culture of bamboo Gigantocloa sp. "Malay Dwarf " was performed. The bamboo plants were first submitted to a range of Si supplementation (0-1.5 mM). After 6 months, a potentially toxic Cu concentration of 1.5 μM Cu(2+) was added. Contrary to many studies on other plants, bamboo growth did not depend on Si levels even though it absorbed Si up to 218 mg g(-1) in leaves. The absorption of Cu by bamboo plants was not altered by the Si supplementation; Cu accumulated mainly in roots (131 mg kg(-1)), but was also found in leaves (16.6 mg kg(-1)) and stems (9.8 mg kg(-1)). Copper addition did not induce any toxicity symptoms. The different Cu and Si absorption mechanisms may partially explain why Si did not influence Cu repartition and concentration in bamboo. Given the high biomass and its absorption capacity, bamboo could potentially tolerate and accumulate high Cu concentrations making this plant useful for wastewater treatment.

  2. Quantification and isotopic analysis of intracellular sulfur metabolites in the dissimilatory sulfate reduction pathway

    Science.gov (United States)

    Sim, Min Sub; Paris, Guillaume; Adkins, Jess F.; Orphan, Victoria J.; Sessions, Alex L.

    2017-06-01

    Microbial sulfate reduction exhibits a normal isotope effect, leaving unreacted sulfate enriched in 34S and producing sulfide that is depleted in 34S. However, the magnitude of sulfur isotope fractionation is quite variable. The resulting changes in sulfur isotope abundance have been used to trace microbial sulfate reduction in modern and ancient ecosystems, but the intracellular mechanism(s) underlying the wide range of fractionations remains unclear. Here we report the concentrations and isotopic ratios of sulfur metabolites in the dissimilatory sulfate reduction pathway of Desulfovibrio alaskensis. Intracellular sulfate and APS levels change depending on the growth phase, peaking at the end of exponential phase, while sulfite accumulates in the cell during stationary phase. During exponential growth, intracellular sulfate and APS are strongly enriched in 34S. The fractionation between internal and external sulfate is up to 49‰, while at the same time that between external sulfate and sulfide is just a few permil. We interpret this pattern to indicate that enzymatic fractionations remain large but the net fractionation between sulfate and sulfide is muted by the closed-system limitation of intracellular sulfate. This 'reservoir effect' diminishes upon cessation of exponential phase growth, allowing the expression of larger net sulfur isotope fractionations. Thus, the relative rates of sulfate exchange across the membrane versus intracellular sulfate reduction should govern the overall (net) fractionation that is expressed. A strong reservoir effect due to vigorous sulfate reduction might be responsible for the well-established inverse correlation between sulfur isotope fractionation and the cell-specific rate of sulfate reduction, while at the same time intraspecies differences in sulfate uptake and/or exchange rates could account for the significant scatter in this relationship. Our approach, together with ongoing investigations of the kinetic isotope

  3. Cytoskeletal Network Morphology Regulates Intracellular Transport Dynamics

    Science.gov (United States)

    Ando, David; Korabel, Nickolay; Huang, Kerwyn Casey; Gopinathan, Ajay

    2015-01-01

    Intracellular transport is essential for maintaining proper cellular function in most eukaryotic cells, with perturbations in active transport resulting in several types of disease. Efficient delivery of critical cargos to specific locations is accomplished through a combination of passive diffusion and active transport by molecular motors that ballistically move along a network of cytoskeletal filaments. Although motor-based transport is known to be necessary to overcome cytoplasmic crowding and the limited range of diffusion within reasonable timescales, the topological features of the cytoskeletal network that regulate transport efficiency and robustness have not been established. Using a continuum diffusion model, we observed that the time required for cellular transport was minimized when the network was localized near the nucleus. In simulations that explicitly incorporated network spatial architectures, total filament mass was the primary driver of network transit times. However, filament traps that redirect cargo back to the nucleus caused large variations in network transport. Filament polarity was more important than filament orientation in reducing average transit times, and transport properties were optimized in networks with intermediate motor on and off rates. Our results provide important insights into the functional constraints on intracellular transport under which cells have evolved cytoskeletal structures, and have potential applications for enhancing reactions in biomimetic systems through rational transport network design. PMID:26488648

  4. Intracellular bacteria: the origin of dinoflagellate toxicity.

    Science.gov (United States)

    Silva, E S

    1990-01-01

    Dinoflagellate blooms of the same species have been registered either as toxic or nontoxic and, in the latter case, toxicity may be of different types. A hypothesis has been formulated according to which the bacteria having in some way taken part in the toxin formation are either inside the dinoflagellate cell or in the nutritive liquid. The presence of intracellular bacteria in those microorganisms has been studied mainly in material from cultures, a few from the sea, and several strains were isolated from different species. Experiments with crossed inoculations have shown that the bacterial strain from Gonyaulax tamarensis caused the cells of some other species to become toxic. From nontoxic clonal cultures of Prorocentrum balticum, Glenodinium foliaceum, and Gyrodinium instriatum, after inoculation of that bacterial strain, cultures were obtained whose cell extracts showed the same kind of toxicity as G. tamarensis. No toxic action could be found in the extracts of the bacterial cells form the assayed strains. The interference of intracellular bacteria in the metabolism of dinoflagellates must be the main cause of their toxicity.

  5. Cytoskeletal Network Morphology Regulates Intracellular Transport Dynamics.

    Science.gov (United States)

    Ando, David; Korabel, Nickolay; Huang, Kerwyn Casey; Gopinathan, Ajay

    2015-10-20

    Intracellular transport is essential for maintaining proper cellular function in most eukaryotic cells, with perturbations in active transport resulting in several types of disease. Efficient delivery of critical cargos to specific locations is accomplished through a combination of passive diffusion and active transport by molecular motors that ballistically move along a network of cytoskeletal filaments. Although motor-based transport is known to be necessary to overcome cytoplasmic crowding and the limited range of diffusion within reasonable timescales, the topological features of the cytoskeletal network that regulate transport efficiency and robustness have not been established. Using a continuum diffusion model, we observed that the time required for cellular transport was minimized when the network was localized near the nucleus. In simulations that explicitly incorporated network spatial architectures, total filament mass was the primary driver of network transit times. However, filament traps that redirect cargo back to the nucleus caused large variations in network transport. Filament polarity was more important than filament orientation in reducing average transit times, and transport properties were optimized in networks with intermediate motor on and off rates. Our results provide important insights into the functional constraints on intracellular transport under which cells have evolved cytoskeletal structures, and have potential applications for enhancing reactions in biomimetic systems through rational transport network design. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  6. Fluorescent nanoparticles for intracellular sensing: a review.

    Science.gov (United States)

    Ruedas-Rama, Maria J; Walters, Jamie D; Orte, Angel; Hall, Elizabeth A H

    2012-11-02

    Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. [Intracellular signaling mechanisms in thyroid cancer].

    Science.gov (United States)

    Mondragón-Terán, Paul; López-Hernández, Luz Berenice; Gutiérrez-Salinas, José; Suárez-Cuenca, Juan Antonio; Luna-Ceballos, Rosa Isela; Erazo Valle-Solís, Aura

    2016-01-01

    Thyroid cancer is the most common malignancy of the endocrine system, the papillary variant accounts for 80-90% of all diagnosed cases. In the development of papillary thyroid cancer, BRAF and RAS genes are mainly affected, resulting in a modification of the system of intracellular signaling proteins known as «protein kinase mitogen-activated» (MAPK) which consist of «modules» of internal signaling proteins (Receptor/Ras/Raf/MEK/ERK) from the cell membrane to the nucleus. In thyroid cancer, these signanling proteins regulate diverse cellular processes such as differentiation, growth, development and apoptosis. MAPK play an important role in the pathogenesis of thyroid cancer as they are used as molecular biomarkers for diagnostic, prognostic and as possible therapeutic molecular targets. Mutations in BRAF gene have been correlated with poor response to treatment with traditional chemotherapy and as an indicator of poor prognosis. To review the molecular mechanisms involved in intracellular signaling of BRAF and RAS genes in thyroid cancer. Molecular therapy research is in progress for this type of cancer as new molecules have been developed in order to inhibit any of the components of the signaling pathway (RET/PTC)/Ras/Raf/MEK/ERK; with special emphasis on the (RET/PTC)/Ras/Raf section, which is a major effector of ERK pathway. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  8. Stochastic models of intracellular calcium signals

    Energy Technology Data Exchange (ETDEWEB)

    Rüdiger, Sten, E-mail: sten.ruediger@physik.hu-berlin.de

    2014-01-10

    Cellular signaling operates in a noisy environment shaped by low molecular concentrations and cellular heterogeneity. For calcium release through intracellular channels–one of the most important cellular signaling mechanisms–feedback by liberated calcium endows fluctuations with critical functions in signal generation and formation. In this review it is first described, under which general conditions the environment makes stochasticity relevant, and which conditions allow approximating or deterministic equations. This analysis provides a framework, in which one can deduce an efficient hybrid description combining stochastic and deterministic evolution laws. Within the hybrid approach, Markov chains model gating of channels, while the concentrations of calcium and calcium binding molecules (buffers) are described by reaction–diffusion equations. The article further focuses on the spatial representation of subcellular calcium domains related to intracellular calcium channels. It presents analysis for single channels and clusters of channels and reviews the effects of buffers on the calcium release. For clustered channels, we discuss the application and validity of coarse-graining as well as approaches based on continuous gating variables (Fokker–Planck and chemical Langevin equations). Comparison with recent experiments substantiates the stochastic and spatial approach, identifies minimal requirements for a realistic modeling, and facilitates an understanding of collective channel behavior. At the end of the review, implications of stochastic and local modeling for the generation and properties of cell-wide release and the integration of calcium dynamics into cellular signaling models are discussed.

  9. Renal cortex copper concentration in acute copper poisoning in calves

    Directory of Open Access Journals (Sweden)

    Luis E. Fazzio

    2012-01-01

    Full Text Available The aim of this study was to estimate the diagnostic value of renal cortex copper (Cu concentration in clinical cases of acute copper poisoning (ACP. A total of 97 calves that died due to subcutaneous copper administration were compiled in eleven farms. At least, one necropsy was conducted on each farm and samples for complementary analysis were taken. The degree of autolysis in each necropsy was evaluated. The cases appeared on extensive grazing calf breeding and intensive feedlot farms, in calves of 60 to 200 kg body weight. Mortality varied from 0.86 to 6.96 %, on the farms studied. The first succumbed calf was found on the farms between 6 and 72 hours after the susbcutaneous Cu administration. As discrepancies regarding the reference value arose, the local value (19.9 parts per million was used, confirming the diagnosis of acute copper poisoning in 93% of the analyzed kidney samples. These results confirm the value of analysis of the cortical kidney Cu concentration for the diagnosis of acute copper poisoning.

  10. Homocysteine restricts copper availability leading to suppression of cytochrome C oxidase activity in phenylephrine-treated cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Xiao Zuo

    Full Text Available Cardiomyocyte hypertrophy induced by phenylephrine (PE is accompanied by suppression of cytochrome c oxidase (CCO activity, and copper (Cu supplementation restores CCO activity and reverses the hypertrophy. The present study was aimed to understand the mechanism of PE-induced decrease in CCO activity. Primary cultures of neonatal rat cardiomyocytes were treated with PE at a final concentration of l00 µM in cultures for 72 h to induce cell hypertrophy. The CCO activity was determined by enzymatic assay and changes in CCO subunit COX-IV as well as copper chaperones for CCO (COX17, SCO2, and COX11 were determined by Western blotting. PE treatment increased both intracellular and extracellular homocysteine concentrations and decreased intracellular Cu concentrations. Studies in vitro found that homocysteine and Cu form complexes. Inhibition of the intracellular homocysteine synthesis in the PE-treated cardiomyocytes prevented the increase in the extracellular homocysteine concentration, retained the intracellular Cu concentration, and preserved the CCO activity. PE treatment decreased protein concentrations of the COX-IV, and the Cu chaperones COX17, COX11, and SCO2. These PE effects were prevented by either inhibition of the intracellular homocysteine synthesis or Cu supplementation. Therefore, PE-induced elevation of homocysteine restricts Cu availability through its interaction with Cu and suppression of Cu chaperones, leading to the decrease in CCO enzyme activity.

  11. Copper metallurgy at the crossroads

    Directory of Open Access Journals (Sweden)

    Habashi F.

    2007-01-01

    Full Text Available Copper technology changed from the vertical to the horizontal furnace and from the roast reaction to converting towards the end of the last century. However, the horizontal furnace proved to be an inefficient and polluting reactor. As a result many attempts were made to replace it. In the past 50 years new successful melting processes were introduced on an industrial scale that were more energy efficient and less polluting. In addition, smelting and converting were conducted in a single reactor in which the concentrate was fed and the raw copper was produced. The standing problem in many countries, however, is marketing 3 tonnes of sulfuric acid per tonne of copper produced as well as emitting large amounts of excess SO2 in the atmosphere. Pressure hydrometallurgy offers the possibility of liberating the copper industry from SO2 problem. Heap leaching technology has become a gigantic operation. Combined with solvent extraction and electrowinning it contributes today to about 20% of copper production and is expected to grow. Pressure leaching offers the possibility of liberating the copper industry from SO2 problem. The technology is over hundred years old. It is applied for leaching a variety of ores and concentrates. Hydrothermal oxidation of sulfide concentrates has the enormous advantage of producing elemental sulfur, hence solving the SO2 and sulfuric acid problems found in smelters. Precipitation of metals such as nickel and cobalt under hydrothermal conditions has been used for over 50 years. It has the advantage of a compact plant but the disadvantage of producing ammonium sulfate as a co-product. In case of copper, however, precipitation takes place without the need of neutralizing the acid, which is a great advantage and could be an excellent substitute for electrowinning which is energy intensive and occupies extensive space. Recent advances in the engineering aspects of pressure equipment design open the door widely for increased

  12. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca(2+) ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...

  13. Effect of Cu2+ and pH on intracellular calcium content and lipid peroxidation in winter wheat roots

    Directory of Open Access Journals (Sweden)

    M. E. Riazanova

    2015-06-01

    Full Text Available The study investigates the effect of copper ions and pH of external solution on intracellular calcium homeostasis and lipid peroxidation in winter wheat roots. Experiment was carried out with winter wheat. Sterile seeds were germinated in Petri dishes on the filter paper soaked with acetic buffer (pH 4.7 and 6.2 at 20 °Cin the dark for 48 hours. Copper was added as CuSO4. It’s concentrations varied from 0 to 50 µM. The Ca2+-fluorescent dye Fluo-3/AM ester was loaded on 60 hour. Root fluorescence with Fluo-3 loading was detected using X-Cite Series 120 Q unit attached to microscope Olympus BX53 with camera Olympus DP72. Imaging of root cells was achieved after exciting with 488 nm laser and collection of emission signals above 512 nm. Preliminary analysis of the images was performed using software LabSens; brightness (fluorescence intensity analysis was carried out by means of ImageJ. Peroxidation of lipids was determined according to Kumar and Knowles method. It was found that pH of solution had effect on release of calcium from intracellular stores. Low pH provokes an increase of [Ca2+]cyt which may be reaction of roots to acidic medium. Copper induces increase in non-selective permeability of plasma membrane and leads to its faster depolarization. This probably initiates Ca-dependent depolarization channels which are responsible for the influx of calcium from apoplast into the cell. Changing of the membrane permeability may occur due to interaction between Cu2+ ions and Ca-binding sites on plasma membrane or may be due to binding of copper with sulfhydryl groups and increasing of POL. Copper may also damage lipid bilayer and change the activity of some non-selective channels and transporters. Reactive oxygen species which are formed under some types of stress factors, especially the effect of heavy metals, can be activators of Ca-channels. Cu2+ ions rise MDA content and promote the oxidative stress. Low medium pH also induces its

  14. Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete

    DEFF Research Database (Denmark)

    Thit, Amalie; Ramskov, Tina; Croteau, Marie-Noële Croteau

    2016-01-01

    the bioavailability and subcellular distribution of copper oxide (CuO) NPs and aqueous Cu (Cu-Aq) in the sediment-dwelling worm Lumbriculus variegatus. Ten days (d) sediment exposure resulted in marginal Cu bioaccumulation in L. variegatus for both forms of Cu. Bioaccumulation was detected because isotopically...... enriched 65Cu was used as a tracer. Neither burrowing behavior or survival was affected by the exposure. Once incorporated into tissue, Cu loss was negligible over 10 d of elimination in clean sediment (Cu elimination rate constants were not different from zero). With the exception of day 10, differences...... in bioaccumulation and subcellular distribution between Cu forms were either not detectable or marginal. After 10 d of exposure to Cu-Aq, the accumulated Cu was primarily partitioned in the subcellular fraction containing metallothionein-like proteins (MTLP, ≈40%) and cellular debris (CD, ≈30%). Cu concentrations...

  15. Erratum - Intracellular heavy metal nanoparticle storage

    Directory of Open Access Journals (Sweden)

    Iannitti T

    2011-01-01

    Full Text Available Iannitti T, Capone S, Gatti A, Capitani F, Cetta F, Palmieri BIntracellular heavy metal nanoparticle storage: progressive accumulation within lymph nodes with transformation from chronic inflammation to malignancy. Int J Nanomedicine. 2010;5:955–960.Dr Federico Capitani’s name was spelt incorrectly as "Frederico Capitani" in the published paper.

  16. Erratum - Intracellular heavy metal nanoparticle storage

    OpenAIRE

    Iannitti T; Capone S; Gatti A; et al

    2011-01-01

    Iannitti T, Capone S, Gatti A, Capitani F, Cetta F, Palmieri BIntracellular heavy metal nanoparticle storage: progressive accumulation within lymph nodes with transformation from chronic inflammation to malignancy. Int J Nanomedicine. 2010;5:955–960.Dr Federico Capitani’s name was spelt incorrectly as "Frederico Capitani" in the published paper.

  17. Determination of copper in whole blood by differential pulse adsorptive stripping voltammetry

    Directory of Open Access Journals (Sweden)

    Tarik Attar

    2014-02-01

    Full Text Available A selective and sensitive method for determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The method is based on adsorptive accumulation of the complexes of Cu (II ions with benzenesulfonyl hydrazide onto hanging mercury drop electrode (HMDE, followed by the reduction of the adsorbed species by differential pulse cathodic stripping voltammetry. The effect of various parameters such as supporting electrolyte, concentration of benzenesulfonyl hydrazide, accumulation potential, accumulation time and stirring rate on the selectivity and sensitivity were studied. The optimum conditions for determination of copper include perchloric acid 0.03 M, concentration of benzenesulfonyl hydrazide 7.5×10-5 M, the accumulation potential of -350 mV (vs. Ag/AgCl, the accumulation time of 50 s, and the scan rate of 50 mV s-1. Under optimized conditions, linear calibration curves were established for the concentration of Cu (II in the range of 0.62-275 ng mL-1, with detection limit of 0.186 ng mL-1 for Cu (II. The procedure was successfully applied to the determination of copper ion in whole blood samples.

  18. Perturbation of intracellular acyl-CoA metabolism induces the unfolded protein response pathway and autophagy in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Færgeman, Nils J.; Feddersen, Søren

    2008-01-01

    autophagy mainly is a response to the stress of nutrient limitation. In the present study, we demonstrate that perturbation of fatty acid synthesis and transport either through inhibition of fatty acid synthase (FAS) or by depleting cells for the acyl-CoA binding protein, Acb1p, leads to induction of Hac1p....... This and the facts that Acb1p-depleted cells are hypersensitive to the immunosuppressive drug rapamycin and accumulate the transcription factor Msn2p in  the nucleus, indicate that perturbation of intracellular acyl-CoA metabolism leads to  a starvation response that upregulate autophagy, which involves both Ras......Eukaryotic cells have developed several strategies to respond and adapt to changes in their intracellular and extracellular environment. The unfolded protein response (UPR) pathway is activated following accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER), whereas...

  19. Bladder-type hydropneumatic accumulators

    International Nuclear Information System (INIS)

    Anigas, F.

    1985-01-01

    Hydropneumatic pressure accumulators allow liquids to be stored under pressure, their operating principle being based on the inherent compressibility of elements in a liquid and gaseous state. A wide range of fluids can be covered by means of the appropriate choice of the material for the body and bladder. Their main applications are: energy accumulation, safety reserve, suspension. (author)

  20. Electrochemical characterization of anode passivation mechanisms in copper electrorefining

    Science.gov (United States)

    Moats, Michael Scott

    Anode passivation can decrease productivity and quality while increasing costs in modern copper electrorefineries. This investigation utilized electrochemical techniques to characterize the passivation behavior of anode samples from ten different operating companies. It is believed that this collection of anodes is the most diverse set ever to be assembled to study the effect of anode composition on passivation. Chronopotentiometry was the main electrochemical technique, employing a current density of 3820 A m-2. From statistical analysis of the passivation characteristics, increasing selenium, tellurium, silver, lead and nickel were shown to accelerate passivation. Arsenic was the only anode impurity that inhibited passivation. Oxygen was shown to accelerate passivation when increased from 500 to 1500 ppm, but further increases did not adversely affect passivation. Nine electrolyte variables were also examined. Increasing the copper, sulfuric acid or sulfate concentration of the electrolyte accelerated passivation. Arsenic in the electrolyte had no effect on passivation. Chloride and optimal concentrations of thiourea and glue delayed passivation. Linear sweep voltammetry, cyclic voltammetry, and impedance spectroscopy provided complementary information. Analysis of the electrochemical results led to the development of a unified passivation mechanism. Anode passivation results from the formation of inhibiting films. Careful examination of the potential details, especially those found in the oscillations just prior to passivation, demonstrated the importance of slimes, copper sulfate and copper oxide. Slimes confine dissolution to their pores and inhibit diffusion. This can lead to copper sulfate precipitation, which blocks more of the surface area. Copper oxide forms because of the resulting increase in potential at the interface between the copper sulfate and anode. Ultimate passivation occurs when the anode potential is high enough to stabilize the oxide film in

  1. Transcriptional activation of glutathione pathways and role of glucose homeostasis during copper imbalance.

    Science.gov (United States)

    Quiroz, Natalia; Rivas, Nicole; del Pozo, Talía; Burkhead, Jason; Suazo, Miriam; González, Mauricio; Latorre, Mauricio

    2015-04-01

    Copper is an essential micronutrient for organism health. Dietary changes or pathologies linked to this metal induce changes in intracellular glutathione concentrations. Here, we studied the transcriptional activation of glutathione pathways in Jurkat cell lines, analyzing the effect of change in glucose homeostasis during a physiological and supra-physiological copper exposure. An immortalized line of human T lymphocyte cell line (Jurkat) was exposed to different copper and glucose conditions to mimic concentrations present in human blood. We applied treatments for 6 (acute) and 24 h (sustained) to 2 µM (physiological) or 20 µM (supra-physiological, Wilson disease scenario) of CuSO4 in combination with 25 mg/dL (hypoglycemia), 100 mg/dL (normal) and 200 mg/dL (hyperglycemia, diabetes scenario) of glucose. The results indicate that a physiological concentration of copper exposure does not induce transcriptional changes in the glutathione synthesis pathway after 6 or 24 h. The G6PDH gene (regeneration pathway), however, is induced during a supra-physiological copper condition. This data was correlated with the viability assays, where fluctuation in both glucose conditions (hypo and hyperglycemia scenario) affected Jurkat proliferation when 20 µM of CuSO4 was added to the culture media. Under a copper overload condition, the transcription of a component of glutathione regeneration pathway (G6PDH gene) is activated in cells chronically exposed to a hyperglycemia scenario, indicating that fluctuations in glucose concentration impact the resistance against the metal. Our findings illustrate the importance of glucose homeostasis during copper excess.

  2. Metabolic Changes in Synechocystis PCC6803 upon Nitrogen-Starvation: Excess NADPH Sustains Polyhydroxybutyrate Accumulation

    Science.gov (United States)

    Hauf, Waldemar; Schlebusch, Maximilian; Hüge, Jan; Kopka, Joachim; Hagemann, Martin; Forchhammer, Karl

    2013-01-01

    Polyhydroxybutyrate (PHB) is a common carbon storage polymer among heterotrophic bacteria. It is also accumulated in some photoautotrophic cyanobacteria; however, the knowledge of how PHB accumulation is regulated in this group is limited. PHB synthesis in Synechocystis sp. PCC 6803 is initiated once macronutrients like phosphorus or nitrogen are limiting. We have previously reported a mutation in the gene sll0783 that impairs PHB accumulation in this cyanobacterium upon nitrogen starvation. In this study we present data which explain the observed phenotype. We investigated differences in intracellular localization of PHB synthase, metabolism, and the NADPH pool between wild type and mutant. Localization of PHB synthase was not impaired in the sll0783 mutant; however, metabolome analysis revealed a difference in sorbitol levels, indicating a more oxidizing intracellular environment than in the wild type. We confirmed this by directly measuring the NADPH/NADP ratio and by altering the intracellular redox state of wild type and sll0783 mutant. We were able to physiologically complement the mutant phenotype of diminished PHB synthase activity by making the intracellular environment more reducing. Our data illustrate that the NADPH pool is an important factor for regulation of PHB biosynthesis and metabolism, which is also of interest for potential biotechnological applications. PMID:24957892

  3. Metabolic Changes in Synechocystis PCC6803 upon Nitrogen-Starvation: Excess NADPH Sustains Polyhydroxybutyrate Accumulation

    Directory of Open Access Journals (Sweden)

    Waldemar Hauf

    2013-02-01

    Full Text Available Polyhydroxybutyrate (PHB is a common carbon storage polymer among heterotrophic bacteria. It is also accumulated in some photoautotrophic cyanobacteria; however, the knowledge of how PHB accumulation is regulated in this group is limited. PHB synthesis in Synechocystis sp. PCC 6803 is initiated once macronutrients like phosphorus or nitrogen are limiting. We have previously reported a mutation in the gene sll0783 that impairs PHB accumulation in this cyanobacterium upon nitrogen starvation. In this study we present data which explain the observed phenotype. We investigated differences in intracellular localization of PHB synthase, metabolism, and the NADPH pool between wild type and mutant. Localization of PHB synthase was not impaired in the sll0783 mutant; however, metabolome analysis revealed a difference in sorbitol levels, indicating a more oxidizing intracellular environment than in the wild type. We confirmed this by directly measuring the NADPH/NADP ratio and by altering the intracellular redox state of wild type and sll0783 mutant. We were able to physiologically complement the mutant phenotype of diminished PHB synthase activity by making the intracellular environment more reducing. Our data illustrate that the NADPH pool is an important factor for regulation of PHB biosynthesis and metabolism, which is also of interest for potential biotechnological applications.

  4. Intracellular pH in sperm physiology.

    Science.gov (United States)

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

    2014-08-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Intracellular Signalling by C-Peptide

    Directory of Open Access Journals (Sweden)

    Claire E. Hills

    2008-01-01

    Full Text Available C-peptide, a cleavage product of the proinsulin molecule, has long been regarded as biologically inert, serving merely as a surrogate marker for insulin release. Recent findings demonstrate both a physiological and protective role of C-peptide when administered to individuals with type I diabetes. Data indicate that C-peptide appears to bind in nanomolar concentrations to a cell surface receptor which is most likely to be G-protein coupled. Binding of C-peptide initiates multiple cellular effects, evoking a rise in intracellular calcium, increased PI-3-kinase activity, stimulation of the Na+/K+ ATPase, increased eNOS transcription, and activation of the MAPK signalling pathway. These cell signalling effects have been studied in multiple cell types from multiple tissues. Overall these observations raise the possibility that C-peptide may serve as a potential therapeutic agent for the treatment or prevention of long-term complications associated with diabetes.

  6. Intracellular Na⁺ and cardiac metabolism.

    Science.gov (United States)

    Bay, Johannes; Kohlhaas, Michael; Maack, Christoph

    2013-08-01

    In heart failure, alterations of excitation-contraction underlie contractile dysfunction. One important defect is an elevation of the intracellular Na(+) concentration in cardiac myocytes ([Na(+)]i), which has an important impact on cytosolic and mitochondrial Ca(2+) homeostasis. While elevated [Na(+)]i is thought to compensate for decreased Ca(2+) load of the sarcoplasmic reticulum (SR), it yet negatively affects energy supply-and-demand matching and can even induce mitochondrial oxidative stress. Here, we review the mechanisms underlying these pathophysiological changes. The chain of events may constitute a vicious cycle of ion dysregulation, oxidative stress and energetic deficit, resembling characteristic cellular deficits that are considered key hallmarks of the failing heart. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes". Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. An intracellular anion channel critical for pigmentation.

    Science.gov (United States)

    Bellono, Nicholas W; Escobar, Iliana E; Lefkovith, Ariel J; Marks, Michael S; Oancea, Elena

    2014-12-16

    Intracellular ion channels are essential regulators of organellar and cellular function, yet the molecular identity and physiological role of many of these channels remains elusive. In particular, no ion channel has been characterized in melanosomes, organelles that produce and store the major mammalian pigment melanin. Defects in melanosome function cause albinism, characterized by vision and pigmentation deficits, impaired retinal development, and increased susceptibility to skin and eye cancers. The most common form of albinism is caused by mutations in oculocutaneous albinism II (OCA2), a melanosome-specific transmembrane protein with unknown function. Here we used direct patch-clamp of skin and eye melanosomes to identify a novel chloride-selective anion conductance mediated by OCA2 and required for melanin production. Expression of OCA2 increases organelle pH, suggesting that the chloride channel might regulate melanin synthesis by modulating melanosome pH. Thus, a melanosomal anion channel that requires OCA2 is essential for skin and eye pigmentation.

  8. Nanobodies: Chemical Functionalization Strategies and Intracellular Applications

    Science.gov (United States)

    Schumacher, Dominik; Helma, Jonas; Schneider, Anselm F. L.; Leonhardt, Heinrich

    2018-01-01

    Abstract Nanobodies can be seen as next‐generation tools for the recognition and modulation of antigens that are inaccessible to conventional antibodies. Due to their compact structure and high stability, nanobodies see frequent usage in basic research, and their chemical functionalization opens the way towards promising diagnostic and therapeutic applications. In this Review, central aspects of nanobody functionalization are presented, together with selected applications. While early conjugation strategies relied on the random modification of natural amino acids, more recent studies have focused on the site‐specific attachment of functional moieties. Such techniques include chemoenzymatic approaches, expressed protein ligation, and amber suppression in combination with bioorthogonal modification strategies. Recent applications range from sophisticated imaging and mass spectrometry to the delivery of nanobodies into living cells for the visualization and manipulation of intracellular antigens. PMID:28913971

  9. Biliary copper excretion by hepatocyte lysosomes in the rat. Major excretory pathway in experimental copper overload

    International Nuclear Information System (INIS)

    Gross, J.B. Jr.; Myers, B.M.; Kost, L.J.; Kuntz, S.M.; LaRusso, N.F.

    1989-01-01

    We investigated the hypothesis that lysosomes are the main source of biliary copper in conditions of hepatic copper overload. We used a rat model of oral copper loading and studied the relationship between the biliary output of copper and lysosomal hydrolases. Male Sprague-Dawley rats were given tap water with or without 0.125% copper acetate for up to 36 wk. Copper loading produced a 23-fold increase in the hepatic copper concentration and a 30-65% increase in hepatic lysosomal enzyme activity. Acid phosphatase histochemistry showed that copper-loaded livers contained an increased number of hepatocyte lysosomes; increased copper concentration of these organelles was confirmed directly by both x ray microanalysis and tissue fractionation. The copper-loaded rats showed a 16-fold increase in biliary copper output and a 50-300% increase in biliary lysosomal enzyme output. In the basal state, excretory profiles over time were similar for biliary outputs of lysosomal enzymes and copper in the copper-loaded animals but not in controls. After pharmacologic stimulation of lysosomal exocytosis, biliary outputs of copper and lysosomal hydrolases in the copper-loaded animals remained coupled: injection of colchicine or vinblastine produced an acute rise in the biliary output of both lysosomal enzymes and copper to 150-250% of baseline rates. After these same drugs, control animals showed only the expected increase in lysosomal enzyme output without a corresponding increase in copper output. We conclude that the hepatocyte responds to an increased copper load by sequestering excess copper in an increased number of lysosomes that then empty their contents directly into bile. The results provide direct evidence that exocytosis of lysosomal contents into biliary canaliculi is the major mechanism for biliary copper excretion in hepatic copper overload

  10. Leaching of Copper Ore by Thiobacillus Ferrooxidans.

    Science.gov (United States)

    Lennox, John; Biaha, Thomas

    1991-01-01

    A quantitative laboratory exercise based upon the procedures copper manufacturers employ to increase copper production is described. The role of chemoautotrophic microorganisms in biogeologic process is emphasized. Safety considerations when working with bacteria are included. (KR)

  11. Electrochemical behaviour of alkaline copper complexes

    Indian Academy of Sciences (India)

    cyanide- plating bath for copper has been developed using alkaline trisodium citrate and triethanolamine solutions5. The present investigation presents cyclic voltammetric studies on the electrochemical behaviour of alkaline copper complexes, ...

  12. Testing Corrosion Inhibitors for the Conservation of Archaeological Copper and Copper Alloys

    Directory of Open Access Journals (Sweden)

    Robert B. Faltermeier

    1997-11-01

    Full Text Available This is a synopsis of the Ph.D. research undertaken at the Institute of Archaeology, University College London. The aim was to evaluate corrosion inhibitors for use in the conservation of copper and copper alloy archaeological artefacts. The objective of this work was to acquire an insight into the performance of copper corrosion inhibitors, when applied to archaeological copper.

  13. Copper tolerance of Trichoderma species

    Directory of Open Access Journals (Sweden)

    Jovičić-Petrović Jelena

    2014-01-01

    Full Text Available Some Trichoderma strains can persist in ecosystems with high concentrations of heavy metals. The aim of this research was to examine the variability of Trichoderma strains isolated from different ecosystems, based on their morphological properties and restriction analysis of ITS fragments. The fungal growth was tested on potato dextrose agar, amended with Cu(II concentrations ranging from 0.25 to 10 mmol/l, in order to identify copper-resistant strains. The results indicate that some isolated strains of Trichoderma sp. show tolerance to higher copper concentrations. Further research to examine the ability of copper bioaccumulation by tolerant Trichoderma strains is needed. [Projekat Ministarstva nauke Republike Srbije, br. TR 31080 i br. III 43010

  14. Mechanochemical reduction of copper sulfide

    DEFF Research Database (Denmark)

    Balaz, P.; Takacs, L.; Jiang, Jianzhong

    2002-01-01

    The mechanochemical reduction of copper sulfide with iron was induced in a Fritsch P-6 planetary mill, using WC vial filled with argon and WC balls. Samples milled for specific intervals were analyzed by XRD and Mossbauer spectroscopy. Most of the reaction takes place during the first 10 min...... of milling and only FeS and Cu are found after 60 min. The main chemical process is accompanied by phase transformations of the sulfide phases as a result of milling. Djurleite partially transformed to chalcocite and a tetragonal copper sulfide phase before reduction. The cubic modification of FeS was formed...... first, transforming to hexagonal during the later stages of the process. The formation of off-stoichiometric phases and the release of some elemental sulfur by copper sulfide are also probable....

  15. Laser sintering of copper nanoparticles

    International Nuclear Information System (INIS)

    Zenou, Michael; Saar, Amir; Ermak, Oleg; Kotler, Zvi

    2014-01-01

    Copper nanoparticle (NP) inks serve as an attractive potential replacement to silver NP inks in functional printing applications. However their tendency to rapidly oxidize has so far limited their wider use. In this work we have studied the conditions for laser sintering of Cu-NP inks in ambient conditions while avoiding oxidation. We have determined the regime for stable, low-resistivity copper (< ×3 bulk resistivity value) generation in terms of laser irradiance and exposure duration and have indicated the limits on fast processing. The role of pre-drying conditions on sintering outcome has also been studied. A method, based on spectral reflectivity measurements, was used for non-contact monitoring of the sintering process evolution. It also indicates preferred spectral regions for sintering. Finally, we illustrated how selective laser sintering can generate high-quality, fine line (<5 µm wide) and dense copper circuits. (paper)

  16. High Intracellular Seed Train BiP Levels Correlate with Poor Production Culture Performance in CHO Cells.

    Science.gov (United States)

    Tung, Meg; Tang, Danming; Wang, Szu-Han; Zhan, Dejin; Kiplinger, Karen; Pan, Shu; Jing, Yifeng; Shen, Amy; Ahyow, Patrick; Snedecor, Brad; Gawlitzek, Martin; Misaghi, Shahram

    2018-04-10

    Consistent cell culture performance is a prerequisite to ensure product quality consistency and achieve productivity goals for the manufacture of recombinant protein therapeutics, including monoclonal antibodies. Here we report a peculiar observation where high levels of intracellular BiP in seed train cultures are consistently predictive of poor cell culture performance in the subsequent inoculum and production cultures for a monoclonal antibody produced in CHO cells. Our investigations suggest that in this cell line the high intracellular BiP levels in the seed train are triggered by a slightly lower culture pH, which interferes with proper antibody folding and secretion. While the seed train culture does not display any obvious signs of the problem at slightly lower culture pH, inoculum trains and production cultures sourced from these low pH seed trains display significantly lower cell growth and cell size. High intracellular BiP levels may interfere with UPR signaling, thereby hampering a proper and timely UPR response in the production media. Studies of other problematic cell lines have shown a similar correlation between intracellular BiP accumulation and poor production performance. We believe intracellular BiP levels in seed train should hence be low in order to increase the success rate in production. This article is protected by copyright. All rights reserved.

  17. The Role of Autophagy in Intracellular Pathogen Nutrient Acquisition

    Directory of Open Access Journals (Sweden)

    Shaun eSteele

    2015-06-01

    Full Text Available Following entry into host cells intracellular pathogens must simultaneously evade innate host defense mechanisms and acquire energy and anabolic substrates from the nutrient-limited intracellular environment. Most of the potential intracellular nutrient sources are stored within complex macromolecules that are not immediately accessible by intracellular pathogens. To obtain nutrients for proliferation, intracellular pathogens must compete with the host cell for newly-imported simple nutrients or degrade host nutrient storage structures into their constituent components (fatty acids, carbohydrates and amino acids. It is becoming increasingly evident that intracellular pathogens have evolved a wide variety of strategies to accomplish this task. One recurrent microbial strategy is to exploit host degradative processes that break down host macromolecules into simple nutrients that the microbe can use. Herein we focus on how a subset of bacterial, viral and eukaryotic pathogens leverage the host process of autophagy to acquire nutrients that support their growth within infected cells

  18. Refining processes in the copper casting technology

    OpenAIRE

    Rzadkosz, S.; Kranc, M.; Garbacz-Klempka, A.; Kozana, J.; Piękoś, M.

    2015-01-01

    The paper presents the analysis of technology of copper and alloyed copper destined for power engineering casts. The casts quality was assessed based on microstructure, chemical content analysis and strength properties tests. Characteristic deoxidising (Logas, Cup) and modifying (ODM2, Kupmod2) formulas were used for the copper where high electrical conductivity was required. Chosen examples of alloyed copper with varied Cr and Zr content were studied, and the optimal heat treatment parameter...

  19. Potential for phytoextraction of copper by Sinapis alba and Festuca rubra cv. Merlin grown hydroponically and in vineyard soils.

    Science.gov (United States)

    Malagoli, Mario; Rossignolo, Virginia; Salvalaggio, Nico; Schiavon, Michela

    2014-03-01

    The extensive use of copper-bearing fungicides in vineyards is responsible for the accumulation of copper (Cu) in soils. Grass species able to accumulate Cu could be cultivated in the vineyard inter-rows for copper phytoextraction. In this study, the capacity of Festuca rubra cv Merlin and Sinapis alba to tolerate and accumulate copper (Cu) was first investigated in a hydroponic system without the interference of soil chemical-physical properties. After the amendment of Cu (5 or 10 mg Cu l-(1)) to nutrient solution, shoot Cu concentration in F. rubra increased up to 108.63 mg Cu kg(-1) DW, more than three times higher than in S. alba (31.56 mg Cu kg(-1) DW). The relationship between Cu concentration in plants and external Cu was dose-dependent and species specific. Results obtained from the hydroponic experiment were confirmed by growing plants in pots containing soil collected from six Italian vineyards. The content of soil organic matter was crucial to enhance Cu tolerance and accumulation in the shoot tissues of both plant species. Although S. alba produced more biomass than F. rubra in most soils, F. rubra accumulated significantly more Cu (up to threefold to fourfold) in the shoots. Given these results, we recommended that F. rubra cv Merlin could be cultivated in the vineyard rows to reduce excess Cu in vineyard soils.

  20. Influence of preexposure to sublethal levels of copper on Cu-64 uptake and distribution among tissues of the European eel ( Anguilla anguilla )

    DEFF Research Database (Denmark)

    Grosell, M.; Boetius, I.; Hansen, H.J.M.

    1996-01-01

    was studied by the uptake of Cu-64 during 67 hr of exposure to 8 and 64 mu g . L(-1). The Cu accumulation rate in muscle tissue was inversely related to bodyweight. Although the accumulation rates in liver and muscle tissues were significantly reduced after 6 and 28 days of preexposure to 64 mu g . L(-1) (but......The effect of preexposure to copper was examined in European eels with respect to uptake and distribution of Cu-64 among tissues. Eels were exposed in freshwater to 8 and 64 mu g Cu . L(-1) for 0, 6 and 28 days before Cu-64 incubation. The accumulation of copper in gill, liver and muscle tissue...... not to 8 mu g . L(-1)), the accumulation rates in the gills were not affected by preexposure. We suggest that the excretion rate of copper was stimulated by the applied preexposure to 64 mu g Cu . L(-1)...

  1. Tunable synthesis of copper nanotubes

    International Nuclear Information System (INIS)

    Kaniukov, E; Yakimchuk, D; Kozlovsky, A; Shlimas, D; Zdorovets, M; Kadyrzhanov, K

    2016-01-01

    Simple method of tunable synthesis of copper nanotubes based on template synthesis was developed. A comprehensive study of the structural, morphological and electrical characteristics of the obtained nanostructures was carried out. Characterization of structural features was made by methods of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry analysis. Evaluation of wall thickness is made by methods of gas permeability. Electrical conductivity of nanotubes was define in the study of their current-voltage characteristics. The possibility to control of copper nanotubes physical properties by variation of the deposition parameters was shown. (paper)

  2. Removal of Copper by Eichhornia crassipes and the Characterization of Associated Bacteria of the Rhizosphere System

    Directory of Open Access Journals (Sweden)

    Raisa Kabeer

    2014-06-01

    Full Text Available Excess doses of trace element contamination make conventional water treatment methods less effective and more expensive, where in alternative biotechnological applications open up new opportunities with their reduced cost and lesser impacts to the environment. In the present investigation, effectiveness of aquatic macrophyte Eichhornia crassipes was tested for the removal of copper in laboratory conditions. Water samples were collected from macrophytes natural habitat and water tubs used for growing E. crassipes and analysed along with plant tissues for Cu content. The work also characterized the associated microbiota of the rhizosphere system of the E. crassipes as well as the wetland system of its occurrence. Copper concentration of the wetland water samples ranged from 0.009 to 0.03ppm. Six bacterial genera (Acinetobacter, Alcaligenes, Bacillus, Kurthia, Listeria and Chromobacterium were represented in rhizosphere of E.crassipes and 4 bacterial genera (Acinetobacter, Bacillus, Listeria and Chromobacterium were recorded in wetland water samples. Copper resistance studies of the bacterial isolates showed that out of 26 isolates from rhizosphere and 19 strains from water samples,12 of them showed low resistance (80% of copper during 15 days experiment. Copper accumulation was found to be high in the root followed by leaf and petiole. Results of the present study concluded that E. crassipes is an efficient plant for the removal of copper.

  3. Urban Mines of Copper: Size and Potential for Recycling in the EU

    Directory of Open Access Journals (Sweden)

    Luca Ciacci

    2017-01-01

    Full Text Available Copper is among the most important metals by production volume and variety of applications, providing essential materials and goods for human wellbeing. Compared to other world regions, Europe has modest natural reserves of copper and is highly dependent on imports to meet the domestic demand. Securing access to raw materials is of strategic relevance for Europe and the recycling of urban mines (also named “in-use stock” is a significant mean to provide forms of secondary copper to the European industry. A dynamic material flow analysis model is applied to characterize the flows of copper in the European Union (EU-28 from 1960 to 2014 and to determine the accumulation of this metal in the in-use stock. A scrap balance approach is applied to reconcile the flow of secondary copper sent to domestic recycling estimated through the model and that reported by historic statistics. The results show that per capita in-use stock amounts at 160–200 kg/person, and that current end-of-life recycling rate is around 60%. The quantification of historic flows provides a measure of how the European copper cycle has changed over time and how it may evolve in the future: major hindrances to recycling are highlighted and perspectives for improving the current practices at end-of-life are discussed.

  4. Electrical conduction in composites containing copper core–copper ...

    Indian Academy of Sciences (India)

    Unknown

    of Mott's small polaron hopping conduction model. ... sample exhibited a metallic conduction confirming the formation of a percolative chain of ..... value of εp. Also the oxide layer formation on the initially unoxidized copper particles will increase the resistivity level of the nanocomposite. This is borne out by results shown in ...

  5. Joining of alumina via copper/niobium/copper interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Robert A.; Chapman, Daniel R.; Danielson, David T.; Glaeser, Andreas M.

    2000-03-15

    Alumina has been joined at 1150 degrees C and 1400 degrees C using multilayer copper/niobium/copper interlayers. Four-point bend strengths are sensitive to processing temperature, bonding pressure, and furnace environment (ambient oxygen partial pressure). Under optimum conditions, joints with reproducibly high room temperature strengths (approximately equal 240 plus/minus 20 MPa) can be produced; most failures occur within the ceramic. Joints made with sapphire show that during bonding an initially continuous copper film undergoes a morphological instability, resulting in the formation of isolated copper-rich droplets/particles at the sapphire/interlayer interface, and extensive regions of direct bonding between sapphire and niobium. For optimized alumina bonds, bend tests at 800 degrees C-1100 degrees C indicate significant strength is retained; even at the highest test temperature, ceramic failure is observed. Post-bonding anneals at 1000 degrees C in vacuum or in gettered argon were used to assess joint stability and to probe the effect of ambient oxygen partial pressure on joint characteristics. Annealing in vacuum for up to 200 h causes no significant decrease in room temperature bend strength or change in fracture path. With increasing anneal time in a lower oxygen partial pressure environment, the fracture strength decreases only slightly, but the fracture path shifts from the ceramic to the interface.

  6. Structure transitions between copper-sulphate and copper-chloride ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Structure transitions between copper UPD adlayers on Au(111)–(1 × 1) in sulfuric acid and chloride containing electrolyte were investigated by in situ scanning tunnelling microscopy. We demon- strate that co-adsorbed sulphate ions in the (√3 × √3)R30° UPD adlayer are replaced by chloride ions and,.

  7. Strategies of Intracellular Pathogens for Obtaining Iron from the Environment

    Directory of Open Access Journals (Sweden)

    Nidia Leon-Sicairos

    2015-01-01

    Full Text Available Most microorganisms are destroyed by the host tissues through processes that usually involve phagocytosis and lysosomal disruption. However, some organisms, called intracellular pathogens, are capable of avoiding destruction by growing inside macrophages or other cells. During infection with intracellular pathogenic microorganisms, the element iron is required by both the host cell and the pathogen that inhabits the host cell. This minireview focuses on how intracellular pathogens use multiple strategies to obtain nutritional iron from the intracellular environment in order to use this element for replication. Additionally, the implications of these mechanisms for iron acquisition in the pathogen-host relationship are discussed.

  8. Alternative oxidase impacts ganoderic acid biosynthesis by regulating intracellular ROS levels in Ganoderma lucidum.

    Science.gov (United States)

    Shi, Deng-Ke; Zhu, Jing; Sun, Ze-Hua; Zhang, Guang; Liu, Rui; Zhang, Tian-Jun; Wang, Sheng-Li; Ren, Ang; Zhao, Ming-Wen

    2017-10-01

    The alternative oxidase (AOX), which forms a branch of the mitochondrial respiratory electron transport pathway, functions to sustain electron flux and alleviate reactive oxygen species (ROS) production. In this article, a homologous AOX gene was identified in Ganoderma lucidum. The coding sequence of the AOX gene in G. lucidum contains 1038 nucleotides and encodes a protein of 39.48 kDa. RNA interference (RNAi) was used to study the function of AOX in G. lucidum, and two silenced strains (AOXi6 and AOXi21) were obtained, showing significant decreases of approximately 60 and 50 %, respectively, in alternative pathway respiratory efficiency compared to WT. The content of ganoderic acid (GA) in the mutant strains AOXi6 and AOXi21 showed significant increases of approximately 42 and 44 %, respectively, compared to WT. Elevated contents of intermediate metabolites in GA biosynthesis and elevated transcription levels of corresponding genes were also observed in the mutant strains AOXi6 and AOXi21. In addition, the intracellular ROS content in strains AOXi6 and AOXi21 was significantly increased, by approximately 1.75- and 1.93-fold, respectively, compared with WT. Furthermore, adding N-acetyl-l-cysteine (NAC), a ROS scavenger, significantly depressed the intracellular ROS content and GA accumulation in AOX-silenced strains. These results indicate that AOX affects GA biosynthesis by regulating intracellular ROS levels. Our research revealed the important role of AOX in the secondary metabolism of G. lucidum.

  9. Highly Efficient Intracellular Protein Delivery by Cationic Polyethyleneimine-Modified Gelatin Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ming-Ju Chou

    2018-02-01

    Full Text Available Intracellular protein delivery may provide a safe and non-genome integrated strategy for targeting abnormal or specific cells for applications in cell reprogramming therapy. Thus, highly efficient intracellular functional protein delivery would be beneficial for protein drug discovery. In this study, we generated a cationic polyethyleneimine (PEI-modified gelatin nanoparticle and evaluated its intracellular protein delivery ability in vitro and in vivo. The experimental results showed that the PEI-modified gelatin nanoparticle had a zeta potential of approximately +60 mV and the particle size was approximately 135 nm. The particle was stable at different biological pH values and temperatures and high protein loading efficiency was observed. The fluorescent image results revealed that large numbers of particles were taken up into the mammalian cells and escaped from the endosomes into the cytoplasm. In a mouse C26 cell-xenograft cancer model, particles accumulated in cancer cells. In conclusion, the PEI-modified gelatin particle may provide a biodegradable and highly efficient protein delivery system for use in regenerative medicine and cancer therapy.

  10. Intracellular Retention of ABL Kinase Inhibitors Determines Commitment to Apoptosis in CML Cells

    Science.gov (United States)

    Dziadosz, Marek; Schnöder, Tina; Heidel, Florian; Schemionek, Mirle; Melo, Junia V.; Kindler, Thomas; Müller-Tidow, Carsten; Koschmieder, Steffen; Fischer, Thomas

    2012-01-01

    Clinical development of imatinib in CML established continuous target inhibition as a paradigm for successful tyrosine kinase inhibitor (TKI) therapy. However, recent reports suggested that transient potent target inhibition of BCR-ABL by high-dose TKI (HD-TKI) pulse-exposure is sufficient to irreversibly commit cells to apoptosis. Here, we report a novel mechanism of prolonged intracellular TKI activity upon HD-TKI pulse-exposure (imatinib, dasatinib) in BCR-ABL-positive cells. Comprehensive mechanistic exploration revealed dramatic intracellular accumulation of TKIs which closely correlated with induction of apoptosis. Cells were rescued from apoptosis upon HD-TKI pulse either by repetitive drug wash-out or by overexpression of ABC-family drug transporters. Inhibition of ABCB1 restored sensitivity to HD-TKI pulse-exposure. Thus, our data provide evidence that intracellular drug retention crucially determines biological activity of imatinib and dasatinib. These studies may refine our current thinking on critical requirements of TKI dose and duration of target inhibition for biological activity of TKIs. PMID:22815843

  11. A copper vapor laser by using a copper-vapor-complex reaction at a low temperature

    OpenAIRE

    Kano, Toshiyuki; Taniguchi, Hiroshi; Saito, Hiroshi

    1987-01-01

    A copper vapor laser performance by using ametal-vapor-complex reaction (Cu+AlBr3) is reported. The laser operation is obtained at a low temperature without externalheating because of the AlBr3 vapors evaporating at a room temperature. The copper vapor laser using this metal-vapor-complex reaction has an advantage of deposition-free of a metallic copper to the laser tube wall, which is different from the copper halide and the organometallic copper lasers.

  12. Kinetic exploration of nitrate-accumulating microalgae for nutrient recovery.

    Science.gov (United States)

    Coppens, Joeri; Decostere, Bjorge; Van Hulle, Stijn; Nopens, Ingmar; Vlaeminck, Siegfried E; De Gelder, Leen; Boon, Nico

    2014-10-01

    Within sustainable resource management, the recovery of nitrogen and phosphorus nutrients from waste streams is becoming increasingly important. Although the use of microalgae has been described extensively in environmental biotechnology, the potential of nitrate-accumulating microalgae for nutrient recovery has not been investigated yet. The ability of these marine microorganisms to concentrate environmental nitrate within their biomass is remarkable. The aim of this study was to investigate the application potential of nitrate-accumulating diatoms for nutrient recovery from marine wastewaters. The intracellular nitrate storage capacity was quantified for six marine diatom strains in synthetic wastewater. Amphora coffeaeformis and Phaeodactylum tricornutum stored the highest amount of nitrate with respectively 3.15 and 2.10 g N L(-1) of cell volume, which accounted for 17.3 and 4.6 %, respectively, of the total nitrogen content. The growth and nitrate and phosphate uptake of both diatoms were further analyzed and based on these features P. tricornutum showed the highest potential for nutrient recovery. A mathematical model was developed which included intracellular nitrate storage and the kinetic parameters were derived for P. tricornutum. Furthermore, a simulation study was performed to compare the performance of a proposed microalgal nutrient recovery unit with a conventional denitrification system for marine wastewater treatment. Overall, this study demonstrates the potential application of P. tricornutum for saline wastewater treatment with concurrent nitrogen and phosphorus recycling.

  13. Intracellular localization and trafficking of fluorescein-labeled cisplatin in human ovarian carcinoma cells.

    Science.gov (United States)

    Safaei, Roohangiz; Katano, Kuniyuki; Larson, Barrett J; Samimi, Goli; Holzer, Alison K; Naerdemann, Wiltrud; Tomioka, Mika; Goodman, Murray; Howell, Stephen B

    2005-01-15

    We sought to identify the subcellular compartments in which cisplatin [cis-diamminedichloroplatinum (DDP)] accumulates in human ovarian carcinoma cells and define its export pathways. Deconvoluting digital microscopy was used to identify the subcellular location of fluorescein-labeled DDP (F-DDP) in 2008 ovarian carcinoma cells stained with organelle-specific markers. Drugs that block vesicle movement were used to map the traffic pattern. F-DDP accumulated in vesicles and were not detectable in the cytoplasm. F-DDP accumulated in the Golgi, in vesicles belonging to the secretory export pathway, and in lysosomes but not in early endosomes. F-DDP extensively colocalized with vesicles expressing the copper efflux protein, ATP7A, whose expression modulates the cellular pharmacology of DDP. Inhibition of vesicle trafficking with brefeldin A, wortmannin, or H89 increased the F-DDP content of vesicles associated with the pre-Golgi compartments and blocked the loading of F-DDP into vesicles of the secretory pathway. The importance of the secretory pathway was confirmed by showing that wortmannin and H89 increased whole cell accumulation of native DDP. F-DDP is extensively sequestered into vesicular structures of the lysosomal, Golgi, and secretory compartments. Much of the distribution to other compartments occurs via vesicle trafficking. F-DDP detection in the vesicles of the secretory pathway is consistent with a major role for this pathway in the efflux of F-DDP and DDP from the cell.

  14. Strain accumulation in quasicrystalline solids

    International Nuclear Information System (INIS)

    Nori, F.; Ronchetti, M.; Elser, V.

    1988-01-01

    We study the relaxation of 2D quasicrystalline elastic networks when their constituent bonds are perturbed homogeneously. Whereas ideal, quasiperiodic networks are stable against such perturbations, we find significant accumulations of strain in a class of disordered networks generated by a growth process. The grown networks are characterized by root mean square phason fluctuations which grow linearly with system size. The strain accumulation we observe in these networks also grows linearly with system size. Finally, we find a dependence of strain accumulation on cooling rate

  15. Alpha-mangostin inhibits intracellular fatty acid synthase and induces apoptosis in breast cancer cells.

    Science.gov (United States)

    Li, Ping; Tian, Weixi; Ma, Xiaofeng

    2014-06-03

    Fatty acid synthase (FAS) has been proven over-expressed in human breast cancer cells and consequently, has been recognized as a target for breast cancer treatment. Alpha-mangostin, a natural xanthone found in mangosteen pericarp, has a variety of biological activities, including anti-cancer effect. In our previous study, alpha-mangostin had been found both fast-binding and slow-binding inhibitions to FAS in vitro. This study was designed to investigate the activity of alpha-mangostin on intracellular FAS activity in FAS over-expressed human breast cancer cells, and to testify whether the anti-cancer activity of alpha-mangostin may be related to its inhibitory effect on FAS. We evaluated the cytotoxicity of alpha-mangostin in human breast cancer MCF-7 and MDA-MB-231 cells. Intracellular FAS activity was measured by a spectrophotometer at 340 nm of NADPH absorption. Cell Counting Kit assay was used to test the cell viability. Immunoblot analysis was performed to detect FAS expression level, intracellular fatty acid accumulation and cell signaling (FAK, ERK1/2 and AKT). Apoptotic effects were detected by flow cytometry and immunoblot analysis of PARP, Bax and Bcl-2. Small interfering RNA was used to down-regulate FAS expression and/or activity. Alpha-mangostin could effectively suppress FAS expression and inhibit intracellular FAS activity, and result in decrease of intracellular fatty acid accumulation. It could also reduce cell viability, induce apoptosis in human breast cancer cells, increase in the levels of the PARP cleavage product, and attenuate the balance between anti-apoptotic and pro-apoptotic proteins of the Bcl-2 family. Moreover, alpha-mangostin inhibited the phosphorylation of FAK. However, the active forms of AKT, and ERK1/2 proteins were not involved in the changes of FAS expression induced by alpha-mangostin. Alpha-mangostin induced breast cancer cell apoptosis by inhibiting FAS, which provide a basis for the development of xanthone as an agent for

  16. Accumulation of Poly(3-hydroxybutyrate Helps Bacterial Cells to Survive Freezing.

    Directory of Open Access Journals (Sweden)

    Stanislav Obruca

    Full Text Available Accumulation of polyhydroxybutyrate (PHB seems to be a common metabolic strategy adopted by many bacteria to cope with cold environments. This work aimed at evaluating and understanding the cryoprotective effect of PHB. At first a monomer of PHB, 3-hydroxybutyrate, was identified as a potent cryoprotectant capable of protecting model enzyme (lipase, yeast (Saccharomyces cerevisiae and bacterial cells (Cupriavidus necator against the adverse effects of freezing-thawing cycles. Further, the viability of the frozen-thawed PHB accumulating strain of C. necator was compared to that of the PHB non-accumulating mutant. The presence of PHB granules in cells was revealed to be a significant advantage during freezing. This might be attributed to the higher intracellular level of 3-hydroxybutyrate in PHB accumulating cells (due to the action of parallel PHB synthesis and degradation, the so-called PHB cycle, but the cryoprotective effect of PHB granules seems to be more complex. Since intracellular PHB granules retain highly flexible properties even at extremely low temperatures (observed by cryo-SEM, it can be expected that PHB granules protect cells against injury from extracellular ice. Finally, thermal analysis indicates that PHB-containing cells exhibit a higher rate of transmembrane water transport, which protects cells against the formation of intracellular ice which usually has fatal consequences.

  17. Accumulation of Poly(3-hydroxybutyrate) Helps Bacterial Cells to Survive Freezing

    Science.gov (United States)

    Krzyzanek, Vladislav; Mravec, Filip; Hrubanova, Kamila; Samek, Ota; Kucera, Dan; Benesova, Pavla; Marova, Ivana

    2016-01-01

    Accumulation of polyhydroxybutyrate (PHB) seems to be a common metabolic strategy adopted by many bacteria to cope with cold environments. This work aimed at evaluating and understanding the cryoprotective effect of PHB. At first a monomer of PHB, 3-hydroxybutyrate, was identified as a potent cryoprotectant capable of protecting model enzyme (lipase), yeast (Saccharomyces cerevisiae) and bacterial cells (Cupriavidus necator) against the adverse effects of freezing-thawing cycles. Further, the viability of the frozen–thawed PHB accumulating strain of C. necator was compared to that of the PHB non-accumulating mutant. The presence of PHB granules in cells was revealed to be a significant advantage during freezing. This might be attributed to the higher intracellular level of 3-hydroxybutyrate in PHB accumulating cells (due to the action of parallel PHB synthesis and degradation, the so-called PHB cycle), but the cryoprotective effect of PHB granules seems to be more complex. Since intracellular PHB granules retain highly flexible properties even at extremely low temperatures (observed by cryo-SEM), it can be expected that PHB granules protect cells against injury from extracellular ice. Finally, thermal analysis indicates that PHB-containing cells exhibit a higher rate of transmembrane water transport, which protects cells against the formation of intracellular ice which usually has fatal consequences. PMID:27315285

  18. Polycyclic aromatic hydrocarbons storage by Fusarium solani in intracellular lipid vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Verdin, Anthony [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France); Lounes-Hadj Sahraoui, Anissa [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)]. E-mail: lounes@univ-littoral.fr; Newsam, Ray [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Robinson, Gary [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Durand, Roger [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)

    2005-01-01

    Accumulation and elimination of polycyclic aromatic hydrocarbons (PAHs) were studied in the fungus Fusarium solani. When the fungus was grown on a synthetic medium containing benzo[a]pyrene, hyphae of F. solani contained numerous lipid vesicles which could be stained by the lipid-specific dyes: Sudan III and Rhodamine B. The fluorescence produced by Rhodamine B and PAH benzo[a]pyrene were at the same locations in the fungal hyphae, indicating that F. solani stored PAH in pre-existing lipid vesicles. A passive temperature-independent process is involved in the benzo[a]pyrene uptake and storage. Sodium azide, a cytochrome c oxidation inhibitor, and the two cytoskeleton inhibitors colchicine and cytochalasin did not prevent the transport and accumulation of PAH in lipid vesicles of F. solani hyphae. F. solani degraded a large range of PAHs at different rates. PAH intracellular storage in lipid vesicles was not necessarily accompanied by degradation and was common to numerous other fungi. - Fungi can store PAHs intracellularly in lipid vesicles independently of their PAH degradation abilities.

  19. Intracellular Na+ regulation of Na+ pump sites in cultured vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Allen, J.C.; Navran, S.S.; Seidel, C.L.; Dennison, D.K.; Amann, J.M.; Jemelka, S.K.

    1989-01-01

    Enzymatically dispersed cells from canine saphenous vein and femoral artery were grown in fetal calf serum and studied at day 0 (freshly dispersed) through confluence in primary culture. Intracellular Na levels (Nai), but not intracellular K (Ki), were increased after 24 h in culture and then decreased to a steady state by 4 days. Na+ pump site number [( 3 H] ouabain binding) increased through day 3 and remained elevated. Nai was still elevated at 2 days when the Na+ pump site number began to increase. Total pump turnover (maximum ouabain-inhibited 86 Rb uptake) reflected the increase in Na+ pump site number. These key events precede the observed increases in both protein production and cellular proliferation. If the same cells are maintained in defined medium, without fetal calf serum, Nai, Ki, and the number of [ 3 H]ouabain binding sites do not change with time. These data are consistent with the suggestion that the initial mitogenic response of vascular smooth muscle cells to fetal calf serum involves an increased Na+ influx, and a Nai accumulation, caused by low Na+ pump density. The synthesis of new pump sites effects a decrease in the accumulated Nai, which may be related to cell proliferation

  20. The GARP Complex Is Involved in Intracellular Cholesterol Transport via Targeting NPC2 to Lysosomes.

    Science.gov (United States)

    Wei, Jian; Zhang, Ying-Yu; Luo, Jie; Wang, Ju-Qiong; Zhou, Yu-Xia; Miao, Hong-Hua; Shi, Xiong-Jie; Qu, Yu-Xiu; Xu, Jie; Li, Bo-Liang; Song, Bao-Liang

    2017-06-27

    Proper intracellular cholesterol trafficking is critical for cellular function. Two lysosome-resident proteins, NPC1 and NPC2, mediate the egress of low-density lipoprotein-derived cholesterol from lysosomes. However, other proteins involved in this process remain largely unknown. Through amphotericin B-based selection, we isolated two cholesterol transport-defective cell lines. Subsequent whole-transcriptome-sequencing analysis revealed two cell lines bearing the same mutation in the vacuolar protein sorting 53 (Vps53) gene. Depletion of VPS53 or other subunits of the Golgi-associated retrograde protein (GARP) complex impaired NPC2 sorting to lysosomes and caused cholesterol accumulation. GARP deficiency blocked the retrieval of the cation-independent mannose 6-phosphate receptor (CI-MPR) to the trans-Golgi network. Further, Vps54 mutant mice displayed reduced cellular NPC2 protein levels and increased cholesterol accumulation, underscoring the physiological role of the GARP complex in cholesterol transport. We conclude that the GARP complex contributes to intracellular cholesterol transport by targeting NPC2 to lysosomes in a CI-MPR-dependent manner. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  1. Polycyclic aromatic hydrocarbons storage by Fusarium solani in intracellular lipid vesicles

    International Nuclear Information System (INIS)

    Verdin, Anthony; Lounes-Hadj Sahraoui, Anissa; Newsam, Ray; Robinson, Gary; Durand, Roger

    2005-01-01

    Accumulation and elimination of polycyclic aromatic hydrocarbons (PAHs) were studied in the fungus Fusarium solani. When the fungus was grown on a synthetic medium containing benzo[a]pyrene, hyphae of F. solani contained numerous lipid vesicles which could be stained by the lipid-specific dyes: Sudan III and Rhodamine B. The fluorescence produced by Rhodamine B and PAH benzo[a]pyrene were at the same locations in the fungal hyphae, indicating that F. solani stored PAH in pre-existing lipid vesicles. A passive temperature-independent process is involved in the benzo[a]pyrene uptake and storage. Sodium azide, a cytochrome c oxidation inhibitor, and the two cytoskeleton inhibitors colchicine and cytochalasin did not prevent the transport and accumulation of PAH in lipid vesicles of F. solani hyphae. F. solani degraded a large range of PAHs at different rates. PAH intracellular storage in lipid vesicles was not necessarily accompanied by degradation and was common to numerous other fungi. - Fungi can store PAHs intracellularly in lipid vesicles independently of their PAH degradation abilities

  2. MUC1 intra-cellular trafficking is clathrin, dynamin, and rab5 dependent

    International Nuclear Information System (INIS)

    Liu Xiaolong; Yuan Zhenglong; Chung, Maureen

    2008-01-01

    MUC1, a transmembrane glycoprotein, is abnormally over-expressed in most human adenocarcinomas. MUC1 association with cytoplasmic cell signal regulators and nuclear accumulation are important for its tumor related activities. Little is known about how MUC1 translocates from the cell membrane to the cytoplasm. In this study, live cell imaging was used to study MUC1 intracellular trafficking. The interaction between EGFR and MUC1 was mapped by FRET analysis and EGF stimulated MUC1 endocytosis was observed directly through live cell imaging. MUC1-CT endocytosis was clathrin and dynamin dependent. Rab5 over-expression resulted in decreased cell membrane localization of MUC1, with accumulation of MUC1 endocytic vesicles in the peri-nuclear region. Conversely, over-expression of a Rab5 dominant negative mutant (S34N) resulted in redistribution of MUC1 from the peri-nuclear region to the cytoplasm. Collectively, these results indicated that MUC1 intra-cellular trafficking occurs through a regulated process that was stimulated by direct EGFR and MUC1 interaction, mediated by clathrin coated pits that were dynamin dependent and regulated by Rab5

  3. on THICKNESS OF COPPER (|) OXIDE

    African Journals Online (AJOL)

    2006-12-20

    Dec 20, 2006 ... semiconductor devices. The oxide is. Observed to be an attractive starting material for the production of solar cells for low cost terrestrial conversion of solar energy to electricity. Copper (I) oxide is one Of the earliest known photovoltaic materials and the first in which the photovOltaic effect was successfully ...

  4. Control of biofouling on titanium condenser tubes with the use of electroless copper plating

    International Nuclear Information System (INIS)

    Anandkumar, B.; George, R.P.; Kamachi Mudali, U.; Ramachandran, D.

    2015-01-01

    In sea water environments titanium condenser tubes face serious issues of biofouling and biomineralization. Electroless plating of nanocopper film is attempted inside the tubes for the control of biofilm formation. Using advanced techniques like AFM, SEM, and XPS, electroless copper plated flat Ti specimens were characterized. Examination of Cu coated Ti surfaces using AFM and SEM showed more reduction in the microroughness compared to anodized Ti surface. Cu 2p 3/2 peak in XPS spectral analysis showed the shift in binding energy inferring the reduction of the hydroxide to metallic copper. Tubular specimens were exposed to sea water up to three months and withdrawn at monthly intervals to evaluate antibacterial activity and long term stability of the coating. Total viable counts and epifluorescence microscopy analyses showed two orders decrease in bacterial counts on copper coated Ti specimens when compared to as polished control Ti specimens. Molecular biology techniques like DGGE and protein expression analysis system were done to get insight into the community diversity and copper tolerance of microorganisms. DGGE gel bands clearly showed the difference in the bacterial diversity inferring from the 16S rRNA gene fragments (V3 regions). Protein analysis showed distinct protein spots appearing in electroless copper coated Ti biofilm protein samples in addition to protein spots common to both the biofilms of Cu coated and as polished Ti. The results indicated copper accumulating proteins in copper resistant bacterial species of biofilm. Reduced microroughness of the surface and toxic copper ions resulted in good biofouling control even after three months exposure to sea water. (author)

  5. A Study of Protection of Copper Alloys

    International Nuclear Information System (INIS)

    Kim, E. A.; Kim, S. H.; Kim, C. R.

    1974-01-01

    Volatile treatment of high capacity boiler water with hydrazine and ammonia is studied. Ammonia comes from the decomposition of excess hydrazine injected to treat dissolved oxygen. Ammonia is also injected for the control of pH. To find an effect of such ammonia on the copper alloy, the relations between pH and iron, and ammonia and copper are studied. Since the dependence of corrosion of iron on pH differs from that of copper, a range of pH was selected experimentally to minimize the corrosion rates of both copper and iron. Corrosion rates of various copper alloys are also compared

  6. Chronic copper toxicity in a dairy herd

    OpenAIRE

    Perrin, David J.; Schiefer, H. Bruno; Blakley, Barry R.

    1990-01-01

    The addition of excessive copper to a commercially prepared dairy ration caused chronic copper toxicity in a dairy herd. A formulation error by a feed company resulted in copper levels of 800 to 1,000 mg/kg in the “as fed concentrate,” amounting to about 400-500 mg copper/kg of the whole ration. Five animals died with typical signs of acute copper toxicity, including intravascular hemolysis and methemoglobinemia. A further 39 cows died on the farm from a combination of debilitation and second...

  7. Disruption of the Arabidopsis CGI-58 homologue produces Chanarin–Dorfman-like lipid droplet accumulation in plants

    OpenAIRE

    James, Christopher N.; Horn, Patrick J.; Case, Charlene R.; Gidda, Satinder K.; Zhang, Daiyuan; Mullen, Robert T.; Dyer, John M.; Anderson, Richard G. W.; Chapman, Kent D.

    2010-01-01

    CGI-58 is the defective gene in the human neutral lipid storage disease called Chanarin-Dorfman syndrome. This disorder causes intracellular lipid droplets to accumulate in nonadipose tissues, such as skin and blood cells. Here, disruption of the homologous CGI-58 gene in Arabidopsis thaliana resulted in the accumulation of neutral lipid droplets in mature leaves. Mass spectroscopy of isolated lipid droplets from cgi-58 loss-of-function mutants showed they contain triacylglycerols with common...

  8. Copper-cadmium interaction in mice: effects of copper status on retention and distribution of cadmium after cadmium exposure

    International Nuclear Information System (INIS)

    Bourcier, D.R.

    1982-01-01

    The role of increased dietary copper in altering the accumulation of cadmium and other metals in tissues, was investigated. Female Swiss-Webster mice were pretreated with cadmium or copper in drinking water for three weeks prior to cadmium exposure for an additional nine weeks, with sub groups from each dose level receiving Cu additions to the Cd supplemented water. In Cd pretreated animals, a significant decrease was observed in Cd concentrations in liver and kidney when Cu was added to Cd in drinking water. Cadmium levels in soluble protein fractions of liver of animals administered 5 ppm Cd were approximately three fold greater than that for the same Cd dose when Cu was added. The same was the case for the metallothionein-like protein fraction (MTP) of the liver cytosol. In copper pretreated animals similar trends were noted in that brain, spleen, liver (but not kidney) Cd levels were decreased in animals receiving Cu additions to the Cd dose. Increased binding of Cd to the MTP fraction was observed after both in vivo and in vitro exposure of intestinal mucosal cells to cadmium

  9. Controlling Copper Electrochemical Deposition (ECD)

    Science.gov (United States)

    West, Michael; McDonald, Robert; Anderson, Marc; Kingston, Skip; Mui, Rudy

    2003-09-01

    The implementation of copper processing in semiconductor manufacturing has resulted in major process development and manufacturing challenges. A fundamental understanding of the copper plating processes used in manufacturing has been limited by the lack of in-line methods for direct measurement and control of process chemistry. Plating bath chemistry adjustments and change-out frequencies are currently determined using a combination of indirect electrochemical monitoring techniques, off-line analyses of wafer metrology and analytical lab measurements. There have been a number of industry reports of major process startup delays, yield management problems and reliability issues as a result of these difficulties. A new in-process mass spectrometry (IPMS) approach enables automated, real-time measurement of both the inorganic components and organic additives in the copper electroplating chemistry as they change during production. The tool is not only capable of real time direct quantification of the copper, chloride, pH, and organic additives in the plating bath, but can also monitor additive breakdown byproducts as they occur during the production process. These breakdown products, as well as changes in the original bath constituent composition can be expected to have a major impact on process performance. We are now in the process of measuring longer term plating bath stability and chemistry changes in prototype applications in semiconductor fab manufacturing environments. The first results demonstrate improved process understanding and the potential for greatly improved process control. We will discuss the technical challenges that were successfully addressed in developing the IPMS capability for application to the copper plating process and the initial process data subsequently obtained.

  10. Selective determination of trace copper(II) by cathodic adsorptive stripping voltammetry with a naphthol-derivative Schiff's base.

    Science.gov (United States)

    Shamsipur, Mojtaba; Saeidi, Mahboubeh; Sharghi, Hashem; Naeimi, Hossein

    2003-01-01

    A selective and sensitive stripping voltammetric method for the determination of trace amounts of copper(II) with a recently synthesized naphthol-derivative Schiff's base (2,2'-[1,2-ethanediylbis(nitriloethylidyne)]bis(1-naphthalene)) is presented. The method is based on adsorptive accumulation of the resulting copper-Schiff's base complex on a hanging mercury drop electrode, followed by the stripping voltammetric measurement at the reduction current of adsorbed complex at -0.15 V (vs. Ag/AgCl). The optimal conditions for the stripping analysis of copper include pH 5.5 to 6.5, 8 microM Schiff's base and an accumulation potential of -0.05 V (vs. Ag/AgCI). The peak current is linearly proportional to the copper concentration over a range 2.3-50.8 ng ml(-1) with a limit of detection of 1.9 ng ml(-1). The accumulation time and RSD are 90 s and (3.2-3.5)%, respectively. The method was applied to the determination of copper in some analytical grade salts, tap water, human serum and sheep's liver.

  11. Intracellular Shuttle: The Lactate Aerobic Metabolism

    Directory of Open Access Journals (Sweden)

    Rogério Santos de Oliveira Cruz

    2012-01-01

    Full Text Available Lactate is a highly dynamic metabolite that can be used as a fuel by several cells of the human body, particularly during physical exercise. Traditionally, it has been believed that the first step of lactate oxidation occurs in cytosol; however, this idea was recently challenged. A new hypothesis has been presented based on the fact that lactate-to-pyruvate conversion cannot occur in cytosol, because the LDH enzyme characteristics and cytosolic environment do not allow the reaction in this way. Instead, the Intracellular Lactate Shuttle hypothesis states that lactate first enters in mitochondria and only then is metabolized. In several tissues of the human body this idea is well accepted but is quite resistant in skeletal muscle. In this paper, we will present not only the studies which are protagonists in this discussion, but the potential mechanism by which this oxidation occurs and also a link between lactate and mitochondrial proliferation. This new perspective brings some implications and comes to change our understanding of the interaction between the energy systems, because the product of one serves as a substrate for the other.

  12. An intracellular anion channel critical for pigmentation

    Science.gov (United States)

    Bellono, Nicholas W; Escobar, Iliana E; Lefkovith, Ariel J; Marks, Michael S; Oancea, Elena

    2014-01-01

    Intracellular ion channels are essential regulators of organellar and cellular function, yet the molecular identity and physiological role of many of these channels remains elusive. In particular, no ion channel has been characterized in melanosomes, organelles that produce and store the major mammalian pigment melanin. Defects in melanosome function cause albinism, characterized by vision and pigmentation deficits, impaired retinal development, and increased susceptibility to skin and eye cancers. The most common form of albinism is caused by mutations in oculocutaneous albinism II (OCA2), a melanosome-specific transmembrane protein with unknown function. Here we used direct patch-clamp of skin and eye melanosomes to identify a novel chloride-selective anion conductance mediated by OCA2 and required for melanin production. Expression of OCA2 increases organelle pH, suggesting that the chloride channel might regulate melanin synthesis by modulating melanosome pH. Thus, a melanosomal anion channel that requires OCA2 is essential for skin and eye pigmentation. DOI: http://dx.doi.org/10.7554/eLife.04543.001 PMID:25513726

  13. Intracellular recording from a spider vibration receptor.

    Science.gov (United States)

    Gingl, Ewald; Burger, Anna-M; Barth, Friedrich G

    2006-05-01

    The present study introduces a new preparation of a spider vibration receptor that allows intracellular recording of responses to natural mechanical or electrical stimulation of the associated mechanoreceptor cells. The spider vibration receptor is a lyriform slit sense organ made up of 21 cuticular slits located on the distal end of the metatarsus of each walking leg. The organ is stimulated when the tarsus receives substrate vibrations, which it transmits to the organ's cuticular structures, reducing the displacement to about one tenth due to geometrical reasons. Current clamp recording was used to record action potentials generated by electrical or mechanical stimuli. Square pulse stimulation identified two groups of sensory cells, the first being single-spike cells which generated only one or two action potentials and the second being multi-spike cells which produced bursts of action potentials. When the more natural mechanical sinusoidal stimulation was applied, differences in adaptation rate between the two cell types remained. In agreement with prior extracellular recordings, both cell types showed a decrease in the threshold tarsus deflection with increasing stimulus frequency. Off-responses to mechanical stimuli have also been seen in the metatarsal organ for the first time.

  14. LIPID SYNTHESIS, INTRACELLULAR TRANSPORT, AND SECRETION

    Science.gov (United States)

    Stein, Olga; Stein, Yechezkiel

    1967-01-01

    In the mammary glands of lactating albino mice injected intravenously with 9, 10-oleic acid-3H or 9, 10-palmitic acid-3H, it has been shown that the labeled fatty acids are incorporated into mammary gland glycerides. The labeled lipid in the mammary gland 1 min after injection was in esterified form (> 95%), and the radioautographic reaction was seen over the rough endoplasmic reticulum and over lipid droplets, both intracellular and intraluminal. At 10–60 min after injection, the silver grains were concentrated predominantly over lipid droplets. There was no concentration of radioactivity over the granules in the Golgi apparatus, at any time interval studied. These findings were interpreted to indicate that after esterification of the fatty acid into glycerides in the rough endoplasmic reticulum an in situ aggregation of lipid occurs, with acquisition of droplet form. The release of the lipid into the lumen proceeds directly and not through the Golgi apparatus, in contradistinction to the mode of secretion of casein in the mammary gland or of lipoprotein in the liver. The presence of strands of endoplasmic reticulum attached to intraluminal lipid droplets provides a structural counterpart to the milk microsomes described in ruminant milk. PMID:6033535

  15. On the Computing Potential of Intracellular Vesicles.

    Science.gov (United States)

    Mayne, Richard; Adamatzky, Andrew

    2015-01-01

    Collision-based computing (CBC) is a form of unconventional computing in which travelling localisations represent data and conditional routing of signals determines the output state; collisions between localisations represent logical operations. We investigated patterns of Ca2+-containing vesicle distribution within a live organism, slime mould Physarum polycephalum, with confocal microscopy and observed them colliding regularly. Vesicles travel down cytoskeletal 'circuitry' and their collisions may result in reflection, fusion or annihilation. We demonstrate through experimental observations that naturally-occurring vesicle dynamics may be characterised as a computationally-universal set of Boolean logical operations and present a 'vesicle modification' of the archetypal CBC 'billiard ball model' of computation. We proceed to discuss the viability of intracellular vesicles as an unconventional computing substrate in which we delineate practical considerations for reliable vesicle 'programming' in both in vivo and in vitro vesicle computing architectures and present optimised designs for both single logical gates and combinatorial logic circuits based on cytoskeletal network conformations. The results presented here demonstrate the first characterisation of intracelluar phenomena as collision-based computing and hence the viability of biological substrates for computing.

  16. Fungal accumulation of metals from building materials during brown rot wood decay.

    Science.gov (United States)

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Jellison, Jody

    2014-08-01

    This study analyzes the accumulation and translocation of metal ions in wood during the degradation performed by one strain of each of the three brown rot fungi; Serpula lacrymans, Meruliporia incrassata and Coniophora puteana. These fungi species are inhabitants of the built environment where the prevention and understanding of fungal decay is of high priority. This study focuses on the influence of various building materials in relation to fungal growth and metal uptake. Changes in the concentration of iron, manganese, calcium and copper ions in the decayed wood were analyzed by induced coupled plasma spectroscopy and related to wood weight loss and oxalic acid accumulation. Metal transport into the fungal inoculated wood was found to be dependent on the individual strain/species. The S. lacrymans strain caused a significant increase in total iron whereas the concentration of copper ions in the wood appeared decreased after 10 weeks of decay. Wood inoculated with the M. incrassata isolate showed the contrary tendency with high copper accumulation and low iron increase despite similar weight losses for the two strains. However, significantly lower oxalic acid accumulation was recorded in M. incrassata degraded wood. The addition of a building material resulted in increased weight loss in wood degraded by C. puteana in the soil-block test; however, this could not be directly linked specifically to the accumulation of any of the four metals recorded. The accumulation of oxalic acid seemed to influence the iron uptake. The study assessing the influence of the presence of soil and glass in the soil-block test revealed that soil contributed the majority of the metals for uptake by the fungi and contributed to increased weight loss. The varying uptake observed among the three brown rot fungi strains toward the four metals analyzed may be related to the specific non-enzymatic and enzymatic properties including bio-chelators employed by each of the species during wood

  17. Modeling HIV-1 intracellular replication: two simulation approaches

    NARCIS (Netherlands)

    Zarrabi, N.; Mancini, E.; Tay, J.; Shahand, S.; Sloot, P.M.A.

    2010-01-01

    Many mathematical and computational models have been developed to investigate the complexity of HIV dynamics, immune response and drug therapy. However, there are not many models which consider the dynamics of virus intracellular replication at a single level. We propose a model of HIV intracellular

  18. Pico gauges for minimally invasive intracellular hydrostatic pressure measurements

    DEFF Research Database (Denmark)

    Knoblauch, Jan; Mullendore, Daniel L.; Jensen, Kaare Hartvig

    2014-01-01

    Intracellular pressure has a multitude of functions in cells surrounded by a cell wall or similar matrix in all kingdoms of life. The functions include cell growth, nastic movements, and penetration of tissue by parasites. The precise measurement of intracellular pressure in the majority of cells...

  19. Intracellular angiotensin II inhibits heterologous receptor stimulated Ca2+ entry

    NARCIS (Netherlands)

    Filipeanu, CM; Brailoiu, E; Henning, RH; Deelman, LE; de Zeeuw, D; Nelemans, SA

    2001-01-01

    Recent studies show that angiotensin II (AngII) can act from within the cell, possibly via intracellular receptors pharmacologically different from typical plasma membrane AngII receptors. The role of this intracellular AngII (AngII(i)) is unclear. Besides direct effects of AngII(i) on cellular

  20. Development of bacterial cell-based system for intracellular ...

    African Journals Online (AJOL)

    Development of bacterial cell-based system for intracellular antioxidant activity screening assay using green fluorescence protein (GFP) reporter. ... Both strains demonstrated that quercetin and α- tocopherol exhibited the most potent and significant antioxidant activity with more than 60% reduction of intracellular superoxide ...

  1. Serum copper and ceruloplasmin levels and urinary copper excretion in thermal injury.

    Science.gov (United States)

    Boosalis, M G; McCall, J T; Solem, L D; Ahrenholz, D H; McClain, C J

    1986-12-01

    Conflicting reports regarding copper status in thermal injury patients have been published. We determined serial serum-copper and serum-ceruloplasmin levels and 24-h urinary excretion of copper in 23 patients with second- and third-degree thermal burns. Throughout hospitalization, mean serum-copper concentration was significantly depressed; lowest levels were found in patients with greater than 40% total body surface area burns. Serum ceruloplasmin was also depressed, an unexpected finding because this protein is a positive acute-phase reactant poststress. Mean urinary excretion of copper was elevated, reaching 2.5 times the upper limit of normal 2 wk postburn. Depressed serum-copper levels paralleled the serum-ceruloplasmin levels rather than the increased urinary-copper losses. Further studies are required to determine the mechanism(s) of this altered copper metabolism and whether physiological or biochemical evidence of copper deficiency accompanies the observed hypocupremia.

  2. Variations of serum copper values in pregnancy

    Directory of Open Access Journals (Sweden)

    Vukelić Jelka

    2012-01-01

    Full Text Available Introduction. Copper is essential micronutrient and has an important role in the human body. The serum copper increases during pregnancy and is doubled at full term. Lower levels of serum copper in pregnancy are connected with some pathological conditions. Objective. The aim of this study was to estimate the levels of serum copper in normal and pathological pregnancies, comparing them with values of serum copper in non-pregnant women, to determine if serum copper is lower in some pathological pregnancies and if this is of some importance. Methods. A total of 2170 plasma samples for copper analyses were made in the following groups: healthy non-pregnant women; healthy pregnant women from the 5th-40th gestational week, during the first delivery stage and during the first three postpartum weeks, in pregnant women with habitual abortion, imminent abortion, abortion in progress, missed abortion (9th-24th weeks, missed labour and premature rupture of membranes (29th-40th weeks. Levels of serum copper were determined by colorimetric technique of bathocuproin with disulphate as a chromogen. Results. Serum copper values in non-pregnant women range from 11.6-25.8 μmol/L. In healthy pregnant women, there is a constant trend of the increase of serum copper. The mean serum copper values revealed three significant peaks at the 22nd, 27th and 35th gestational week. Serum copper values in the patients with some pathological pregnancies in relation to the serum copper values of the healthy pregnant women were significantly lower. Conclusion. Serum copper values can be used as an indicator of some pathological pregnancies.

  3. Acumulação de cobre e zinco em tecidos do feijoeiro em relação com o extraído do solo Accumulation of copper and zinc in the snap bean tissues in relation to that extracted from the soil

    Directory of Open Access Journals (Sweden)

    Tatiana Marsola

    2005-03-01

    Cu content in aerial part and roots increased in proportion to the doses added to soil. The accumulation of Cu in the roots was ten times greater than that found in the aerial part and increased with the Cu rates in soil up to 5.0 mmol kg-1. At application rate of 5.0 mmol kg-1 of soil, beans did not show phytotoxicity symptoms and the Cu concentration in the aerial part was below the normal level. The DTPA solution showed the best correlation of soil-Cu with aerial part-Cu and root-Cu. The contents of Zn in the bean root tissues increased with increasing contents of metal in soil. The Zn concentration in the roots (330 mg kg-1 was greater than found in the aerial part (310 mg kg-1. But did not show toxicity symptoms in the leaves even in the highest Zn rates and did not reduce the dry matter production. The three soil-Zn extraction solutions showed high correlation with Zn concentration in the aerial part and in the roots of beans.

  4. Analysis of Intracellular Metabolites from Microorganisms: Quenching and Extraction Protocols.

    Science.gov (United States)

    Pinu, Farhana R; Villas-Boas, Silas G; Aggio, Raphael

    2017-10-23

    Sample preparation is one of the most important steps in metabolome analysis. The challenges of determining microbial metabolome have been well discussed within the research community and many improvements have already been achieved in last decade. The analysis of intracellular metabolites is particularly challenging. Environmental perturbations may considerably affect microbial metabolism, which results in intracellular metabolites being rapidly degraded or metabolized by enzymatic reactions. Therefore, quenching or the complete stop of cell metabolism is a pre-requisite for accurate intracellular metabolite analysis. After quenching, metabolites need to be extracted from the intracellular compartment. The choice of the most suitable metabolite extraction method/s is another crucial step. The literature indicates that specific classes of metabolites are better extracted by different extraction protocols. In this review, we discuss the technical aspects and advancements of quenching and extraction of intracellular metabolite analysis from microbial cells.

  5. Patterns and Regulation of Silicon Accumulation in Synechococcus spp.

    Science.gov (United States)

    Brzezinski, M. A.; Krause, J. W.; Twining, B. S.; Baines, S. B.; Collier, J.

    2016-02-01

    Culture experiments confirm the accumulation of significant amounts of Si by six clones of marine Synechococcus representing four clades from a variety of marine habitats. Both cellular Si levels and the rate of Si accumulation in Synechococcus respond proportionately to changes in the concentration of silicic acid in the external medium. Si quota is inversely related to growth rate implying growth rate dilution of cellular Si quotas. The rate of Si accumulation as a function of silicic acid concentration is bi-linear between 1 and 500 μM Si(OH)4 with an abrupt increase in the slope at 100 μM. The linear response at environmentally-relevant [Si(OH)4] implies that in the surface ocean Synechococcus acquire Si through diffusion rather than through active transport. However, some evidence was obtained for Si uptake through a phosphate transporter under low-nutrient conditions. If all water-soluble Si associated with Synechococcus cells is internal, internal cellular concentrations would be above seawater silicic acid saturation (i.e. 2 millimolar) implying the existence of a large pool of organically bound silicic acid, as has been hypothesized for diatoms. Organic complexation of intracellular Si would both prevent spontaneous precipitation of amorphous silica and maintain low internal free silicic acid concentrations to drive a diffusive flux of silicic acid into the cell. Our experiments were not designed to address the specific evolutionary or physiological roles played by Si, if any, in Synechococcus. A partial answer will involve determining the chemical environment of Si within Synechococcus and whether the organism has evolved specific molecules that target and bind Si intracellularly or whether the internal complexation of Si is gratuitous.

  6. Acute toxicity of a mixture of copper and single-walled carbon nanotubes to Daphnia magna.

    Science.gov (United States)

    Kim, Ki T; Klaine, Stephen J; Lin, Sijie; Ke, Pu C; Kim, Sang D

    2010-01-01

    Nanomaterials released into the environment will interact with many materials including other contaminants. This may influence bioavailability and fate of both the nanoparticles and the other contaminants. The present study examined the effect of a combination of soluble copper and surface-modified single-walled carbon nanotubes (SWNTs) on Daphnia magna. Lysophosphatidylcholine (LPC) was used to modify the surface of SWNTs, reducing the surface hydrophobicity of the tubes and thereby producing a stable aqueous nanoparticle suspension. The toxicity of the nanoparticle-copper (Cu) mixture was determined to be additive. The addition of nontoxic concentration of LPC-SWNTs enhanced the uptake and toxicity of copper. Greater amounts of Cu were shown to accumulate in D. magna upon addition of 0.5 and 1.0 mg/L LPC-SWNTs.

  7. Clusterin (apolipoprotein J), a molecular chaperone that facilitates degradation of the copper-ATPases ATP7A and ATP7B.

    Science.gov (United States)

    Materia, Stephanie; Cater, Michael A; Klomp, Leo W J; Mercer, Julian F B; La Fontaine, Sharon

    2011-03-25

    The copper-transporting P(1B)-type ATPases (Cu-ATPases) ATP7A and ATP7B are key regulators of physiological copper levels. They function to maintain intracellular copper homeostasis by delivering copper to secretory compartments and by trafficking toward the cell periphery to export excess copper. Mutations in the genes encoding ATP7A and ATP7B lead to copper deficiency and toxicity disorders, Menkes and Wilson diseases, respectively. This report describes the interaction between the Cu-ATPases and clusterin and demonstrates a chaperone-like role for clusterin in facilitating their degradation. Clusterin interacted with both ATP7A and ATP7B in mammalian cells. This interaction increased under conditions of oxidative stress and with mutations in ATP7B that led to its misfolding and mislocalization. A Wilson disease patient mutation (G85V) led to enhanced ATP7B turnover, which was further exacerbated when cells overexpressed clusterin. We demonstrated that clusterin-facilitated degradation of mutant ATP7B is likely to involve the lysosomal pathway. The knockdown and overexpression of clusterin increased and decreased, respectively, the Cu-ATPase-mediated copper export capacity of cells. These results highlight a new role for intracellular clusterin in mediating Cu-ATPase quality control and hence in the normal maintenance of copper homeostasis, and in promoting cell survival in the context of disease. Based on our findings, it is possible that variations in clusterin expression and function could contribute to the variable clinical expression of Menkes and Wilson diseases.

  8. Metal accumulation in wild-caught opossum.

    Science.gov (United States)

    Lockhart, J Mitchell; Siddiqui, Samreen; Loughry, W J; Bielmyer-Fraser, Gretchen K

    2016-06-01

    The Virginia opossum (Didelphis virginiana) is widespread in the USA, ranging south through Latin America. The ecology of opossums is such that they are in frequent contact with soils, suggesting that they may function as a valuable bioindicator for chemical contamination in terrestrial environments. Surprisingly, there have been virtually no toxicology studies on opossums. Here, we provide the first analysis of metal contaminants in opossum liver tissues. Liver samples were obtained from 471 opossums, collected from 2003 to 2006, at four sites in North Florida and South Georgia, USA, and concentrations of copper, lead, nickel, selenium, and zinc were measured. We found little evidence of age differences in the concentration of any of the metals. However, there were at least some significant differences between years, males and females, and between sites for each metal, although the pattern of these differences was not always consistent across metals. Concentrations of metals in liver tissue were positively correlated with one another, primarily of each metal (except Pb) with zinc. Reference levels of metal contaminants are not available for opossums, but concentrations of Cu, Ni, Pb, and Zn in our samples were for the most part significantly higher than those reported from liver tissues of nine-banded armadillos (Dasypus novemcinctus) collected at the same sites and in the same years. Data from other small mammals studied elsewhere further indicate that metal concentrations in opossums were high, but at this time, it is not possible to determine if these elevated levels generated toxicity. The substantial temporal and spatial variation we found in metal concentrations suggests that determination of baseline levels for opossums may not be straightforward. Nonetheless, this is the first study quantifying metal accumulation in the livers of Didelphis virginiana and, as such, provides an important starting point for future research.

  9. Electrochemical in-situ impregnation of wood using a copper nail as source for copper

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Block, Thomas; Nymark, Morten

    2011-01-01

    A new method for copper impregnation of wood in structures was suggested and tested in laboratory scale with specimen of new pine sapwood. A copper nail and a steel screw were placed in the wood, and an electric direct current field was applied, so the copper nail was anode and the screw...... was cathode. At the anode, copper ions were generated. The copper ions were transported into the wood by electromigration (movement of ions in an applied electric field) towards the cathode, and a volume between the two electrodes was thereby impregnated. Copper also moved to a lesser degree in the opposite...

  10. Ammonia leaching of copper smelter dust and precipitation as copper sulphide

    International Nuclear Information System (INIS)

    Morales, A.; Hevia, J. F.; Cifuentes, G.

    2009-01-01

    The effect of ammonia on the leaching of copper smelter dust and copper precipitation from these solutions as sulphide using sulfur and sulfur dioxide was studied. The precipitation was done in ammoniacal media because this solution produced more satisfactory results at room temperature that a sulphuric media. A solid was precipitated containing 60 % of copper of the dust smelter. The other waste generated contained around 80 % of the arsenic of the original copper smelter dust. Based on the preliminary results obtained in this work it will propose a procedure for the recovery of copper as sulphide from copper smelter dust with parallel confinement of arsenic. (Author) 14 refs.

  11. A comparison of metal accumulation by the cnidarian Hydra vulgaris directly from water or

    Directory of Open Access Journals (Sweden)

    Wanchamai Karntanut

    2007-05-01

    Full Text Available The cnidarian Hydra has been widely used to assess the acute toxicity of freshwater pollutants, but very little is known about pollutant accumulation by this animal. The purpose of this study was to measurethe accumulation of the three metals, i.e., copper, cadmium and zinc directly from water and also via its prey and to relate the recorded tissue concentrations to any change in biological activities. It was found thatcopper, cadmium and zinc all were accumulated in the tissues of Hydra exposed directly to the metals in water and also those exposed indirectly through feeding on contaminated prey. The bioconcentration factor(BCF recorded at 48 hours following direct uptake from water was greatest for copper (773, followed by cadmium (409 and zinc (125, although the greatest increase in body burden occurred with cadmium, Metal body burdens of Hydra fed on contaminated prey (Artemia increased in the same metal sequence as fordirect uptake from water and the increase was highest (250 times that of control Hydra for cadmium; however, biomagnification factors (BMFs were all < 1.0 indicating that there was little potential for increasingaccumulation via the food chain. There was significant inhibition of regeneration and bud production in polyps which had fed on cadmium-containing Artemia but not on copper or zinc- containing Artemia.

  12. Effects of copper-oxide nanoparticles, dissolved copper and ultraviolet radiation on copper bioaccumulation, photosynthesis and oxidative stress in the aquatic macrophyte Elodea nuttallii.

    Science.gov (United States)

    Regier, Nicole; Cosio, Claudia; von Moos, Nadia; Slaveykova, Vera I

    2015-06-01

    In this study, the uptake and sub-toxic effects of CuO nanoparticles (CuO-NPs), dissolved Cu(II) alone or in combination with UV radiation on the aquatic macrophyte Elodea nuttallii were studied. Emphasis was on Cu accumulation, growth, photosynthesis and the oxidative stress related enzymes peroxidase (POD) and superoxide dismutase (SOD). The results showed stronger Cu accumulation in plants exposed to 10 mg L(-1) CuO-NPs, corresponding to 1.4-2 mg L(-1) dissolved Cu(II), than to 256 μg L(-1) Cu(II). However, the ratio between the accumulated Cu and dissolved Cu in CuO treatments was lower than in Cu(II) treatments. Additional UV exposure increased accumulation in both treatments, with the effect being stronger for Cu accumulation from CuO-NPs than for dissolved Cu(II). Photosynthetic capacity was strongly reduced by UV treatment, whereas remained unaffected by Cu(II) or CuO-NP treatments. Similarly, the increase of SOD activity was more pronounced in the UV treatments. On the other hand, POD activity enhancement was strongest in the plants exposed to CuO-NPs for 24 h. Expression of the copper transporter COPT1 as revealed by RT-qPCR was inhibited by Cu(II) and CuO-NP treatment, limiting the uptake of excess Cu into the cells. Overall, the combined exposure of E. nuttallii to UV radiation with CuO-NPs or Cu(II) has a higher impact than exposure to CuO-NPs or Cu(II) alone. The results imply that heavy pollution of natural water with CuO-NPs or dissolved Cu might have stronger effects in combination with natural UV irradiation on organisms in situ. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Induced Plant Accumulation of Lithium

    Directory of Open Access Journals (Sweden)

    Laurence Kavanagh

    2018-02-01

    Full Text Available Lithium’s (Li value h