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222 records returned

Response of antioxidant defense system to chromium (VI)-induced cytotoxicity in human diploid cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The aim of this study is to establish antioxidant indicators of chromium toxicity in fetal human lung fibroblasts (HLF). The results obtained corroborate and develop our earlier observation of low-dose and long-term action of Cr(VI) on human cells in culture. In the case of a nontoxic chromium dose, temporary oxidative stress is overcome by increased activity of the antioxidant system with correlation to cell cycle re-entry. The toxic concentrations misbalance the cell antioxidant defense systems and cause irreversible growth arrest and massive cell death by apoptosis. Sub-toxicity is defined as toxicity stretched in t...
Source: Biometals - November 15, 2009 Category: Biochemistry Authors: Asatiani N, Abuladze M, Kartvelishvili T, Kulikova N, Asanishvili L, Holman HY, Sapojnikova N Tags: Biometals Source Type: journals

Serum zinc is decreased in Alzheimer's disease and serum arsenic correlates positively with cognitive ability.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Zinc, copper, and iron aggregate Abeta and accumulate in Alzheimer's disease (AD) plaques. Some metals are increased in AD vs. control serum. The authors examined levels of 12 metals in serum of 44 AD and 41 control subjects. Zinc decreased from 12.3 to 10.9 mumol/L (means, p = 0.0007). Arsenic positively correlated with Mini-Mental State Examination score (p < 0.0001). Zinc deposition in brain amyloid might deplete zinc from other body compartments, such as serum. The arsenic correlation might be caused by the major contribution of seafood consumption to intake of both arsenic and docosahexaenoic acid, of which the...
Source: Biometals - November 13, 2009 Category: Biochemistry Authors: Baum L, Chan IH, Cheung SK, Goggins WB, Mok V, Lam L, Leung V, Hui E, Ng C, Woo J, Chiu HF, Zee BC, Cheng W, Chan MH, Szeto S, Lui V, Tsoh J, Bush AI, Lam CW, Kwok T Tags: Biometals Source Type: journals

Characterization of NikR-responsive promoters of urease and metal transport genes of Helicobacter mustelae.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, the H. mustelae NikR regulator directly controls nickel-responsive regulation of ureases and metal transporters. The improved consensus NikR operator sequence allows the prediction of additional NikR targets in Helicobacter genomes, as demonstrated by the identification of a new nickel-repressed outer membrane protein in H. mustelae. PMID: 19894125 [PubMed - as supplied by publisher] (Source: Biometals)
Source: Biometals - November 6, 2009 Category: Biochemistry Authors: Stoof J, Kuipers EJ, van Vliet AH Tags: Biometals Source Type: journals

Cadmium exposure modifies lactotrophs activity associated to genomic and morphological changes in rat pituitary anterior lobe.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Cadmium (Cd) is widely used in industrial applications and is an important contaminant of agricultural products. As an endocrine disruptor, Cd modifies the hormone release of pituitary anterior lobe (PAL). This work was undertaken to evaluate a possible association between phospholipase D (PLD) and prolactin mRNA expressions and the activity of lactotrophs and folliculostellate cells (FSC) in PAL of Cd exposed adult male Wistar rats (Cd, 0.133 mM per liter for 2 months). The PALs were submitted to immunohistochemical and morphometric analysis to determine the percentage of lactotrophs (PRL-ir) and FSC (S-100-ir). Cultu...
Source: Biometals - November 6, 2009 Category: Biochemistry Authors: Calderoni AM, Biaggio V, Acosta M, Oliveros L, Mohamed F, Giménez MS Tags: Biometals Source Type: journals

Quantitative analysis and functional evaluation of zinc ion in the D: -hydantoinase from Pseudomonas putida YZ-26.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this report, we prepared apo-HDT (metal-removed HDT) and Zn(2+)-HDT (Zn(2+)-added HDT) in vitro from a recombinant HDT (re-HDT) expressed in E. coli. The Zn(2+)-HDT and re-HDT contain 2.17 and 0.95 mol Zn(2+) per mol subunit, respectively, and they have comparable enzymatic activities. In contrast, the apo-HDT only retains 0.04 mol Zn(2+) per mol subunit with less than 10% activity, compared with the re-HDT. When the apo-HDT was reconstituted with ZnCl(2), the enzymatic activity recovery was about 75%. Moreover, the fluorescence intensity, circular dichroism spectra and thermo-stability of the apo-HDT and Zn(2+)-HDT are...
Source: Biometals - November 5, 2009 Category: Biochemistry Authors: Zhang X, Yuan J, Niu L, Liang A Tags: Biometals Source Type: journals

Temporal production of the two Bacillus anthracis siderophores, petrobactin and bacillibactin.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Bacillus anthracis secretes two siderophores, petrobactin (PB) and bacillibactin (BB). These siderophores were temporally produced during germination and outgrowth of spores (the usual infectious form of B. anthracis) in low-iron medium. The siderophore PB was made first while BB secretion began several hours later. Spore outgrowth early in an infection may require PB, whereas delayed BB production suggests a role for BB in the later stages of the infection. Incubation of cultures (inoculated as vegetative cells) at 37 degrees C, as compared to 2 degrees C, increased PB production and decreased secretion of BB, suggest...
Source: Biometals - October 8, 2009 Category: Biochemistry Authors: Wilson MK, Abergel RJ, Arceneaux JE, Raymond KN, Byers BR Tags: Biometals Source Type: journals

Pentavalent methylated arsenicals are substrates of human AQP9.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we examined the uptake of the two pentavalent organic arsenicals by human AQP9 in Xenopus laevis oocytes. Xenopus laevis oocytes microinjected with AQP9 cRNA exhibited uptake of both MAs(V) and DMAs(V) in a pH-dependent manner. The rate of transport was much higher at acidic pH (pH5.5) than at neutral pH. Hg(II), an aquaporin inhibitor, inhibited transport of As(III), MAs(III), MAs(V) and DMAs(V) via AQP9. However, phloretin, which inhibits water and glycerol permeation via AQP9, can only inhibit transport of pentavalent MAs(V) and DMAs(V) but not trivalent As(III) and MAs(III), indicating the translocation ...
Source: Biometals - October 3, 2009 Category: Biochemistry Authors: McDermott JR, Jiang X, Beene LC, Rosen BP, Liu Z Tags: Biometals Source Type: journals

Crystal structure, DNA binding studies, nucleolytic property and topoisomerase I inhibition of zinc complex with 1,10-phenanthroline and 3-methyl-picolinic acid.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Crystal structure analysis of the zinc complex establishes it as a distorted octahedral complex, bis(3-methylpicolinato-kappa(2) N,O)(2)(1,10-phenanthroline-kappa(2) N,N)-zinc(II) pentahydrate, [Zn(3-Me-pic)(2)(phen)].5H(2)O. The trans-configuration of carbonyl oxygen atoms of the carboxylate moieties and orientation of the two planar picolinate ligands above and before the phen ligand plane seems to confer DNA sequence recognition to the complex. It cannot cleave DNA under hydrolytic condition but can slightly be activated by hydrogen peroxide or sodium ascorbate. Circular Dichroism and Fluorescence spectroscopic anal...
Source: Biometals - September 28, 2009 Category: Biochemistry Authors: Seng HL, Von ST, Tan KW, Maah MJ, Ng SW, Rahman RN, Caracelli I, Ng CH Tags: Biometals Source Type: journals

Elevated zinc induces endothelial apoptosis via disruption of glutathione metabolism: role of the ADP translocator.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Zinc is the second-most abundant transition metal within cells and an essential micronutrient. Although adequate zinc is essential for cellular function, intracellular free zinc (Zn(2+)) is tightly controlled, as sustained increases in free Zn(2+) levels can directly contribute to apoptotic endothelial cell death. Moreover, exposure of endothelial cells to acute nitrosative and/or oxidative stress induces a rapid rise of Zn(2+) with mitochondrial dysfunction and the initiation of apoptosis. This apoptotic induction can be mimicked through addition of exogenous ZnCl(2) and mitigated by zinc-chelation strategies, indicat...
Source: Biometals - September 21, 2009 Category: Biochemistry Authors: Wiseman DA, Sharma S, Black SM Tags: Biometals Source Type: journals

First solid state alkaline-earth complexes of monensic acid A (MonH): crystal structure of [M(Mon)(2)(H (2)O) (2)] (M = Mg, Ca), spectral properties and cytotoxicity against aerobic Gram-positive bacteria.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Alkaline-earth metal complexes of the monoanionic form of the polyether ionophore monensin A were isolated for the first time in solid state and were structurally characterized using various spectroscopic methods (IR, NMR, FAB-MS). The stoichiometric reaction of monensic acid (MonH) with M(2+) (M = Mg, Ca) in the presence of an organic base leads to the formation of mononuclear complexes of composition [M(Mon)(2)(H(2)O)(2)]. The structures of magnesium (1) and calcium (2) monensin complexes in the solid state were established by single crystal X-ray crystallography. The complexes crystallize as [Mg(Mon)(2)(H(2)O)(2)].5...
Source: Biometals - September 20, 2009 Category: Biochemistry Authors: Pantcheva IN, Zhorova R, Mitewa M, Simova S, Mayer-Figge H, Sheldrick WS Tags: Biometals Source Type: journals

Effect of copper on the activation of the acid phosphatase from the green algae Pseudokirchneriella subcapitata.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The presence of copper in water environment may have detrimental effects on aquatic organisms, including algae, where different enzymatic systems can be affected. Algae acid phosphatase plays important roles in metabolic processes such as decomposition of organic phosphate, autophagic digestive process, recycling cellular materials and zygote formation during reproduction. This work describes an in vitro activation effect of copper on the acid phosphatase of the green algae Pseudokirchneriella subcapitata (formely Selenastrum capricornutum) under preincubation condition. Apparent Michaelis constant values of 1.21 and 0...
Source: Biometals - September 18, 2009 Category: Biochemistry Authors: Jonsson CM, Aoyama H Tags: Biometals Source Type: journals

Advanced glycation end products and antioxidant status in nondiabetic and streptozotocin induced diabetic rats: effects of copper treatment.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The effects of Cu(II) supplementation on glycemic parameters, advanced glycation end products (AGEs), antioxidant status (glutathione; GSH and total antioxidant capacity; TAOC) and lipid peroxidative damage (thiobarbituric acid-reactive substances, TBARS) were investigated in streptozotocin (STZ) induced diabetic rats. The study was carried out on Wistar albino rats grouped as control (n = 10), CuCl(2) treated (n = 9), STZ (n = 10) and STZ,CuCl(2) treated (n = 9). STZ was administered intraperitoneally at a single dose of 65 mg/kg and CuCl(2), 4 mg copper/kg, subcutaneously, every 2 days for 60 days. At the end of this...
Source: Biometals - September 18, 2009 Category: Biochemistry Authors: Civelek S, Gelişgen R, Andican G, Seven A, Küçük SH, Ozdoğan M, Burçak G Tags: Biometals Source Type: journals

Zinc transporter expression profiles in the rat prostate following alterations in dietary zinc.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Zinc plays important roles in numerous cellular activities and physiological functions. Intracellular zinc levels are strictly maintained by zinc homeostatic mechanisms. Zinc concentrations in the prostate are the highest of all soft tissues and could be important for prostate health. However, the mechanisms by which the prostate maintains high zinc levels are still unclear. In addition, the response of the prostate to alterations in dietary zinc is unknown. The current study explored cellular zinc levels and zinc transporter expression profiles in the lobes of the prostate during dietary marginal zinc depletion. Rats ...
Source: Biometals - September 16, 2009 Category: Biochemistry Authors: Song Y, Elias V, Wong CP, Scrimgeour AG, Ho E Tags: Biometals Source Type: journals

Zinc activates neutrophils' oxidative burst.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Zinc has been shown to disturb the innate host defense response by interfering in the activation of neutrophils and subsequent oxidative burst, although the exact role of this metal, either as an activator or inhibitor, remains a matter of controversy among research groups. These apparent discrepancies may be due to experimental settings, through modification of zinc availability to neutrophils, or to inaccurate detections of reactive species. Thus, the main objective of the present study was to provide clarification on the role of zinc on the activation of human neutrophils and the subsequent oxidative burst. For that...
Source: Biometals - September 16, 2009 Category: Biochemistry Authors: Freitas M, Porto G, Lima JL, Fernandes E Tags: Biometals Source Type: journals

Cadmium effects on p38/MAPK isoforms in MDA-MB231 breast cancer cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study we examined whether exposure of MDA-MB231 tumor cells from the human breast to Cd may exert some effect on p38 isoform expression and accumulation, as well as on p38 activation. Employing a combination of proliferation tests, conventional and semiquantitative multiplex (SM)-polymerase chain reaction (PCR) and Western blot assays, we report that the treatment of breast cancer cells with 5 muM CdCl(2) induces a diversified modulation of the transcription patterns of p38 isoform genes and of the accumulation of the related protein products, which are, on the other hand, also affected by alpha and beta isoform fu...
Source: Biometals - September 14, 2009 Category: Biochemistry Authors: Casano C, Agnello M, Sirchia R, Luparello C Tags: Biometals Source Type: journals

EfeO-cupredoxins: major new members of the cupredoxin superfamily with roles in bacterial iron transport.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The EfeUOB system of Escherichia coli is a tripartite, low pH, ferrous iron transporter. It resembles the high-affinity iron transporter (Ftr1p-Fet3p) of yeast in that EfeU is homologous to Ftr1p, an integral-membrane iron-permease. However, EfeUOB lacks an equivalent of the Fet3p component-the multicopper oxidase with three cupredoxin-like domains. EfeO and EfeB are periplasmic but their precise roles are unclear. EfeO consists primarily of a C-terminal peptidase-M75 domain with a conserved 'HxxE' motif potentially involved in metal binding. The smaller N-terminal domain (EfeO-N) is predicted to be cupredoxin (Cup) li...
Source: Biometals - August 22, 2009 Category: Biochemistry Authors: Rajasekaran MB, Nilapwar S, Andrews SC, Watson KA Tags: Biometals Source Type: journals

Assessment of chronic mercury exposure within the U.S. population, National Health and Nutrition Examination Survey, 1999-2006.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study provides compelling evidence that I-Hg deposition within the human body is a cumulative process, increasing with age and in the population over time, since 1999, as a result of chronic mercury exposure. Furthermore, our results indicate that I-Hg deposition is associated with the significant biological markers for main targets of exposure, deposition, and effect. Accumulation of focal I-Hg deposits within the human body due to chronic mercury exposure provides a mechanism which suggests a time dependent rise in the population risks for associated disease. PMID: 19697139 [PubMed - as supplied by publisher] (Source: Biometals)
Source: Biometals - August 20, 2009 Category: Biochemistry Authors: Laks DR Tags: Biometals Source Type: journals

Effect of chromium supplementation on the diabetes induced-oxidative stress in liver and brain of adult rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study was designed to investigate the susceptibility of liver and brain tissues, as insulin-independent tissues, of normal adult male rats to the oxidative challenge of subchronic supplementation with chromium picolinate (CrPic) at low (human equivalent) and high doses (2.90 and 13.20 mug Cr kg(-1) day(-1), respectively). Also, the modulative effect of CrPic administration on the enhanced oxidative stress in the liver and brain tissues of alloxan-diabetic rats was studied. Fasting serum glucose level was not modified in normal rats but significantly reduced in diabetic rats that had received CrPic supplement. A mild o...
Source: Biometals - August 19, 2009 Category: Biochemistry Authors: Refaie FM, Esmat AY, Mohamed AF, Aboul Nour WH Tags: Biometals Source Type: journals

Synthesis, characterization and evaluation of antileishmanial activity of copper(II) with fluorinated alpha-hydroxycarboxylate ligands.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, Cu(II) complexes with fluorinated ligands were produced aiming at the development of new, less toxic antileishmanial metallodrugs. Complexes of the general formula CuL(2) (L = lactate, trifluorolactate, 2-hydroxyisobutyrate, trifluoro-2-hydroxyisobutyrate) were synthesized in methanolic medium, purified by crystallization and characterized by elemental analysis and electronic and infrared spectroscopies. In vitro experiments with Leishmania amazonensis promastigotes showed that the trifluorolactate derivative more active than its non-fluorinated counterpart. Our results indicate that fluorinated chelators ma...
Source: Biometals - August 12, 2009 Category: Biochemistry Authors: da Silva Maffei R, Yokoyama-Yasunaka JK, Miguel DC, Uliana SR, Espósito BP Tags: Biometals Source Type: journals

Purification and characterization of mycoferritin from Fusarium verticillioides MRC 826.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The fungus Fusarium verticillioides MRC 826 (ascomycetes species), a toxigenic isolate is capable of synthesizing mycoferritin only upon induction with iron in yeast extract sucrose medium. The molecular mass, yield, iron and carbohydrate contents of the purified mycoferritin were 460 kDa, 0.010 mg/g of wet mycelia, 1.0 and 40.2%, respectively. Native gel electrophoresis of the mycoferritin revealed two bands possibly representing isoforms of ferritin. Subunit analysis by SDS-PAGE showed a single protein subunit of ~24 kDa suggesting similar sized subunits in the structure of apoferritin shell. Immunological cross reac...
Source: Biometals - August 8, 2009 Category: Biochemistry Authors: Validandi V, Rupula K, Beedu SR, Deshpande V Tags: Biometals Source Type: journals

Deficiency in frataxin homologue YFH1 in the yeast Pichia guilliermondii leads to missregulation of iron acquisition and riboflavin biosynthesis and affects sulfate assimilation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Pichia guilliermondii is a representative of yeast species that overproduce riboflavin (vitamin B(2)) in response to iron deprivation. P. guilliermondii YFH1 gene coding for frataxin homologue, eukaryotic mitochondrial protein involved in iron trafficking and storage, was identified and deleted. Constructed P. guilliermondii Deltayfh1 mutant grew very poorly in a sucrose-containing synthetic medium supplemented with sulfate or sulfite as a sole sulfur source. Addition of sodium sulfide, glutathione, cysteine, methionine, N-acetyl-L: -cysteine partially restored growth rate of the mutant suggesting that it is impaired i...
Source: Biometals - July 31, 2009 Category: Biochemistry Authors: Pynyaha YV, Boretsky YR, Fedorovych DV, Fayura LR, Levkiv AI, Ubiyvovk VM, Protchenko OV, Philpott CC, Sibirny AA Tags: Biometals Source Type: journals

Disturbed homeostasis of zinc and other essential elements in the prostate gland dependent on the character of pathological lesions.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, significant changes in the levels of other essential elements were observed. The results apparently confirm the disturbed homeostasis of zinc and other essential elements in the etiology of BPH and PCa. PMID: 19629715 [PubMed - as supplied by publisher] (Source: Biometals)
Source: Biometals - July 22, 2009 Category: Biochemistry Authors: Sapota A, Daragó A, Taczalski J, Kilanowicz A Tags: Biometals Source Type: journals

Comparison of inhibitory activities of zinc oxide ultrafine and fine particulates on IgE-induced mast cell activation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The effects of ultrafine and fine particles of zinc oxide (ZnO) on IgE-dependent mast cell activation were investigated. The rat mast cell line RBL2H3 sensitized with monoclonal anti-ovalbumin (OVA) IgE was challenged with OVA in the presence or absence of ZnO particles and zinc sulfate (ZnSO(4)). Degranulation of RBL2H3 was examined by the release of beta-hexosaminidase. To understand the mechanisms responsible for regulating mast cell functions, the effects of ZnO particles on the levels of intracellular Zn(2+), Ca(2+), phosphorylated-Akt, and global tyrosine phosphorylation were also measured. IgE-induced release of...
Source: Biometals - July 16, 2009 Category: Biochemistry Authors: Yamaki K, Yoshino S Tags: Biometals Source Type: journals

Hydroxamate siderophores of Scedosporium apiospermum.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Scedosporium apiospermum is an emerging pathogen colonizing the airways of patients with cystic fibrosis and causing severe infections in immunocompromised hosts. In order to improve our knowledge on the pathogenic mechanisms of this fungus, we investigated the production of siderophores. Cultivation on CAS medium and specific assays for different classes of siderophores suggested the secretion of hydroxamates. A maximal production was obtained by cultivation of the fungus at alkaline pH in an iron-restricted liquid culture medium. Siderophores were then extracted from the culture filtrate by liquid/liquid extraction, ...
Source: Biometals - July 11, 2009 Category: Biochemistry Authors: Bertrand S, Larcher G, Landreau A, Richomme P, Duval O, Bouchara JP Tags: Biometals Source Type: journals

Biochemical characterization of Helicobacter pylori alpha-1,4 fucosyltransferase: metal ion requirement, donor substrate specificity and organic solvent stability.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The effect of metal ions on the activity, the donor substrate specificity, and the stability in organic solvents of Helicobacter pylori alpha-1,4 fucosyltransferase were studied. The recombinant enzyme was expressed as soluble form in E. coli strain AD494 and purified in a one step affinity chromatography. Its activity was highest in cacodylate buffer at pH 6.5 in the presence of 20 mM Mn(2+) ions at 37 degrees C. Mn(2+) ions could be substituted by other metal ions. In all cases, Mn(2+) ions proofed to be the most effective (Mn(2+) > Co(2+) > Ca(2+) > Mg(2+) > Cu(2+) > Ni(2+) > EDTA). The enzyme show...
Source: Biometals - June 29, 2009 Category: Biochemistry Authors: Rabbani S, Corona F, Ernst B Tags: Biometals Source Type: journals

Selenoprotein P regulation by the glucocorticoid receptor.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Maintenance of the antioxidant activity of selenoproteins is one potential mechanism of the beneficial health effects of selenium. Selenoprotein P is the primary selenium distribution protein of the body as well as the major selenium containing protein in serum. The transcriptional regulation of selenoprotein P is of interest since the extrahepatic expression of this gene has demonstrated differentiation-dependent expression in development as well as under different disease states. SEPP1 displays patterned expression in numerous tissues during development and the loss of SEPP1 expression has been observed in malignancy...
Source: Biometals - June 9, 2009 Category: Biochemistry Authors: Rock C, Moos PJ Tags: Biometals Source Type: journals

The effect of dietary selenium supplementation on cadmium absorption and retention in suckling rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study investigated Cd (as CdCl(2)) absorption, distribution, and retention in suckling rats receiving oral Se supplementation (as Na(2)SeO(3)) in equimolar doses (8 mumol Cd and/or Se per kg b.w./day). Selenium was given either before and during Cd exposure (Se(pre) + Cd group; pre-treatment group) or only during Cd exposure (Se + Cd group). Rats were treated from postnatal day (PND) 6-14 as follows: controls (H(2)O, PND 6-14), Se (PND 10-14), Cd (PND 10-14), Se(pre) + Cd (Se PND 6-14 + Cd PND 10-14) and Se + Cd (Se + Cd PND 10-14). Selenium supplementation, especially pre-treatment, decreased Cd levels in the blood, ...
Source: Biometals - June 4, 2009 Category: Biochemistry Authors: Lazarus M, Orct T, Jurasoviæ J, Blanuša M Tags: Biometals Source Type: journals

Ovarian gene transcription and effect of cadmium pre-exposure during artificial sexual maturation of the European eel (Anguilla anguilla).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
European eels are dangerously threatened with extinction. Recent advances tend to show that pollution could, in addition to other already identified factors, contribute to this drama. In a previous report, cadmium (Cd) pre-exposure was found to strongly stimulate the pituitary-liver-gonad axis of maturing female silver eels, leading, lastly, to oocytes atresia and eels mortality. The present work was performed to get more insights into the effects of Cd pre-exposure on eels' ovaries. The transcription levels of various genes involved in mitochondrial metabolism, in the cellular response to metal (metallothioneins, MTs)...
Source: Biometals - May 30, 2009 Category: Biochemistry Authors: Pierron F, Baudrimont M, Dufour S, Elie P, Bossy A, Lucia M, Massabuau JC Tags: Biometals Source Type: journals

Siderophore sorption to clays.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Siderophores are low molecular weight organic ligands exuded by some aerobic organisms and plants to acquire Fe under Fe-limited conditions. The hydroxamate siderophores may sorb to aluminosilicate clays through a variety of mechanisms depending upon the nature of the clay and of the siderophore along with solution conditions such as pH, ionic strength, and presence of metal cations. They may also affect metal binding to clays. Here, we review previous studies of siderophore sorption to aluminosilicate clays; briefly discuss how the techniques of X-ray diffractometry, Fourier-transform infrared spectroscopy, and X-ray ...
Source: Biometals - May 28, 2009 Category: Biochemistry Authors: Maurice PA, Haack EA, Mishra B Tags: Biometals Source Type: journals

Chemical and biological characterization of siderophore produced by the marine-derived Aureobasidium pullulans HN6.2 and its antibacterial activity.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
After analysis using HPLC and electronic ion spray mass spectroscopy, the purified siderophore produced by the marine-derived Aureobasidium pullulans HN6.2 was found to be fusigen. The purified desferric fusigen still had strong inhibition of growth of the pathogenic Vibrio anguillarum while the fusigen chelated by Fe(3+) lost the ability to inhibit the growth of the pathogenic bacterium. The added iron in the medium repressed expression of the hydroxylase gene encoding ornithine N(5)-oxygenase that catalyzes the N(5)-hydroxylation of ornithine for the first step of siderophore biosynthesis in the yeast cells while exp...
Source: Biometals - May 20, 2009 Category: Biochemistry Authors: Wang W, Chi Z, Liu G, Buzdar MA, Chi Z, Gu Q Tags: Biometals Source Type: journals

Siderophore-mediated iron acquisition in the entomopathogenic bacterium Pseudomonas entomophila L48 and its close relative Pseudomonas putida KT2440.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Pseudomonas entomophila L48 is a recently identified entomopathogenic bacterium which, upon ingestion, kills Drosophila melanogaster, and is closely related to P. putida. The complete genome of this species has been sequenced and therefore a genomic, genetic and structural analysis of the siderophore-mediated iron acquisition was undertaken. P. entomophila produces two siderophores, a structurally new and unique pyoverdine and the secondary siderophore pseudomonine, already described in P. fluorescens species. Structural analysis of the pyoverdine produced by the closely related P. putida KT2440 showed that this strain...
Source: Biometals - May 20, 2009 Category: Biochemistry Authors: Matthijs S, Laus G, Meyer JM, Abbaspour-Tehrani K, Schäfer M, Budzikiewicz H, Cornelis P Tags: Biometals Source Type: journals

Influences of magnesium deficiency and cerium on antioxidant system of spinach chloroplasts.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Magnesium-deficiency conditions applied to spinach cultures caused an oxidative stress status in spinach chloroplast monitored by an increase in reactive oxygen species (ROS) accumulation. The enhancement of lipids peroxide of spinach chloroplast grown in magnesium-deficiency media suggested an oxidative attack that was activated by a reduction of antioxidative defense mechanism measured by analysing the activities of superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, and glutathione reductase, as well as antioxidants such as carotenoids and glutathione content. As the antioxidative response of ...
Source: Biometals - May 6, 2009 Category: Biochemistry Authors: Ze Y, Yin S, Ji Z, Luo L, Liu C, Hong F Tags: Biometals Source Type: journals

Crystal structures, DNA-binding studies and antioxidant activities of the Ln(III) complexes with 7-methoxychromone-3-carbaldehyde-isonicotinoyl hydrazone.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The neutral mononuclear Ln(III) complexes (Ln = La, Sm) with 7-methoxychrom-one-3-carbaldehyde-isonicotinoyl hydrazone ligand (L) have been synthesized, characterized and investigated their interactions with calf-thymus DNA. The results show that the binding affinity of the La(III) complex is stronger than that of the Sm(III) complex and that of the ligand (L). Furthermore, the antioxidant activities of the ligand (L) and its Ln(III) complexes (Ln = La, Sm) were studied in detail. PMID: 19404747 [PubMed - as supplied by publisher] (Source: Biometals)
Source: Biometals - April 29, 2009 Category: Biochemistry Authors: Wang Q, Yang ZY, Qi GF, Qin DD Tags: Biometals Source Type: journals

Transcriptional responses of Haemophilus parasuis to iron-restriction stress in vitro.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, selective capture of transcribed sequences approach was used to investigate the transcriptional responses of H. parasuis to iron-restriction stress. Thirty-six genes were identified to be up-regulated under iron-restricted conditions. Knowledge of the genes involved in adaptation to environments encountered during disease will help understand the mechanisms of pathogenesis for this economically significant bacterium. PMID: 19404748 [PubMed - as supplied by publisher] (Source: Biometals)
Source: Biometals - April 29, 2009 Category: Biochemistry Authors: Xie Q, Jin H, Luo R, Wan Y, Chu J, Zhou H, Shi B, Chen H, Zhou R Tags: Biometals Source Type: journals

Anti-diabetic effects of vanadium(III, IV, V)-chlorodipicolinate complexes in streptozotocin-induced diabetic rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Vanadium(III, IV, V)-chlorodipicolinate (dipic-Cl) complexes, including H[V(III)(dipic-Cl)(2)] . 5H(2)O (V(3)dipic-Cl), V(IV)O(dipic-Cl)(H(2)O)(2) (V(4)dipic-Cl) and K[V(V)O(2)(dipic-Cl)] (V(5)dipic-Cl), were prepared with the indicated oxidation states. Our aim was to evaluate the anti-diabetic effects of V(3)dipic-Cl, V(4)dipic-Cl and V(5)dipic-Cl in streptozotocin-induced diabetic rats. Vanadium complexes were orally administered to diabetic rats at concentrations of 0.1-0.3 mg/ml in the drinking water. We found that vanadium-chlorodipicolinate (V-dipic-Cl) complexes at the concentration of 0.1 mg/ml did not exhibit...
Source: Biometals - April 28, 2009 Category: Biochemistry Authors: Li M, Ding W, Smee JJ, Baruah B, Willsky GR, Crans DC Tags: Biometals Source Type: journals

Duality of effect of La(3+) on mitochondrial permeability transition pore depending on the concentration.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In order to explore the role of mitochondria in proliferation promotion and/or apoptosis induction of lanthanum, the mutual influences between La(3+) and Ca(2+) on mitochondrial permeability transition pore (PTP) opening were investigated with isolated mitochondria from rat liver. The experimental results revealed that La(3+) influence the state of mitochondria in a concentration-dependent biphasic manner. La(3+) in nanomolar concentrations, acting as a Ca(2+) analog, entered mitochondrial matrix via the RuR sensitive Ca(2+) channel and elevated ROS level, leading to opening of PTP indicated by mitochondrial swelling, ...
Source: Biometals - April 27, 2009 Category: Biochemistry Authors: Dong S, Zhao Y, Liu H, Yang X, Wang K Tags: Biometals Source Type: journals

The gene frpB2 of Helicobacter pylori encodes an hemoglobin-binding protein involved in iron acquisition.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Human hemoglobin (Hb) is a metalloprotein used by pathogens as a source of iron during invasive process. It can support the Helicobacter pylori growth and several proteins are induced during iron starvation. However, the identity of those proteins remains unknown. In this work, by in silico analysis we identified FrpB2 in H. pylori genome. This protein was annotated as an iron-regulated outer membrane protein. Multiple amino acid alignment showed the motifs necessary for Hb-binding. We demonstrate the ability of FrpB2 to bind Hb by overlay experiments. In addition, the overexpression of this gene allowed the cell growt...
Source: Biometals - April 9, 2009 Category: Biochemistry Authors: González-López MA, Olivares-Trejo JJ Tags: Biometals Source Type: journals

Siderophores of Marinobacter aquaeolei: petrobactin and its sulfonated derivatives.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Siderophores are low molecular weight, high-affinity iron(III) ligands, produced by bacteria to solubilize and promote iron uptake under low iron conditions. Two prominent structural features characterize the majority of the marine siderophores discovered so far: (1) a predominance of suites of amphiphilic siderophores composed of an iron(III)-binding headgroup that is appended by one or two of a series of fatty acids and (2) a prevalence of siderophores that contain alpha-hydroxycarboxylic acid moieties (e.g., beta-hydroxyaspartic acid or citric acid) which are photoreactive when coordinated to Fe(III). Variation of t...
Source: Biometals - April 9, 2009 Category: Biochemistry Authors: Homann VV, Edwards KJ, Webb EA, Butler A Tags: Biometals Source Type: journals

The redox hypothesis in siderophore-mediated iron uptake.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The viability of iron(III/II) reduction as the initial step in the in vivo release of iron from its thermodynamically stable siderophore complex is explored. PMID: 19357971 [PubMed - as supplied by publisher] (Source: Biometals)
Source: Biometals - April 9, 2009 Category: Biochemistry Authors: Harrington JM, Crumbliss AL Tags: Biometals Source Type: journals

Disturbances of energetic metabolism in rat epididymal epithelial cells as a consequence of chronic lead intoxication.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Adult male Wistar rats were intoxicated with 1% lead acetate (PbAc) administered in drinking water for nine months, which amounts to a period five times longer than the duration of one spermatogenesis. There were mitochondrial ultrastructure disorders of epididymal epithelial cells observed in PbAc-treated rats; also a significant lead-induced decrease in ATP concentration in epididymal epithelial cells (by 32%, P < 0.05), Adenylate Energy Charge value (AEC) (by 8%, P < 0.05) and an increase in ADP (28.5%, P < 0.05), AMP (27%, P < 0.05) and adenosine (by 56%, P < 0.05). The results were measured using hi...
Source: Biometals - April 8, 2009 Category: Biochemistry Authors: Marchlewicz M, Baranowska-Bosiacka I, Kolasa A, Kondarewicz A, Chlubek D, Wiszniewska B Tags: Biometals Source Type: journals

Siderophore production by marine-derived fungi.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Siderophore production by marine-derived fungi has not been extensively explored. Three studies have investigated the ability of marine-derived fungi to produce siderophores in response to iron limitation [(Vala et al. in Indian J Mar Sci 29:339-340, 2000; Can J Microbiol 52:603-607, 2006); Baakza et al. in J Exp Mar Biol Ecol 311:1-9, 2004]. In all, 24 of 28 marine fungal strains were found to secrete hydroxamate or carboxylate siderophores; no evidence was found for production of catecholate siderophores. These studies did not determine the structures of the iron-binding compounds. More recently, a study of the natur...
Source: Biometals - April 7, 2009 Category: Biochemistry Authors: Holinsworth B, Martin JD Tags: Biometals Source Type: journals

Iron trafficking as an antimicrobial target.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Iron is essential for the survival of most organisms. Microbial iron acquisition depends on multiple, sometimes complex steps, many of which are not shared by higher eukaryotes. Depriving pathogenic microbes of iron is therefore a potential antimicrobial strategy. The following minireview briefly describes general elements in microbial iron uptake pathways and summarizes some of the current work aiming at their medicinal inhibition. PMID: 19350396 [PubMed - as supplied by publisher] (Source: Biometals)
Source: Biometals - April 7, 2009 Category: Biochemistry Authors: Frederick RE, Mayfield JA, Dubois JL Tags: Biometals Source Type: journals

Surface modifications based on the cyanobacterial siderophore anachelin: from structure to functional biomaterials design.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This review describes the design, synthesis and evaluation of novel catechol based anchors for surface modification. The anachelin chromophore, the catecholate fragment of the siderophore anachelin from the cyanobacterium Anabaena cylindrica, allows for the immobilization of polyethylene glycol (PEG) on titania and glass surfaces thus rendering them protein resistant and antifouling. It is proposed that catecholate siderophores constitute a class of natural products useful for surface modification similar to dihydroxyphenylalanine and dopamine derived compounds found in mussel adhesive proteins. Second-generation dopam...
Source: Biometals - April 7, 2009 Category: Biochemistry Authors: Gademann K, Kobylinska J, Wach JY, Woods TM Tags: Biometals Source Type: journals

The role of siderophores in iron acquisition by photosynthetic marine microorganisms.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The photosynthetic picocyanobacteria and eukaryotic microorganisms that inhabit the open ocean must be able to supply iron for their photosynthetic and respiratory needs from the subnanomolar concentrations available in seawater. Neither group appears to produce siderophores, although some coastal cyanobacteria do. This is interpreted as an adaptation to the dilute oceanic environment rather than a phylogenetic constraint, since there are cases in which related taxa from different environments have the capacity to produce siderophores. Most photosynthetic marine microorganisms are presumably, however, capable of access...
Source: Biometals - April 3, 2009 Category: Biochemistry Authors: Hopkinson BM, Morel FM Tags: Biometals Source Type: journals

Elemental fingerprinting of tumorous and adjacent non-tumorous tissues from patients with colorectal cancer using ICP-MS, ICP-OES and chemometric analysis.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Tumorous and adjacent non-tumorous paired biopsies from 38 patients with colorectal cancer were analyzed by inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry after low-volume microwave digestion. 18 elements were investigated: Ag, Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, P, Pb, S, Se and Zn. Different chemometric tools were used for data evaluation: Wilcoxon signed rank test, Hieratical clustering analysis, principal component analysis (PCA) and linear discriminant analysis (LDA). With the exception of Al, tumours were observed to have significantly more ele...
Source: Biometals - April 2, 2009 Category: Biochemistry Authors: Lavilla I, Costas M, Miguel PS, Millos J, Bendicho C Tags: Biometals Source Type: journals

Impact of cadmium on aquatic bird Cairina moschata.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The impact on palmiped Cairina moschata of two levels of dietary cadmium (Cd) contamination (C1: 1 mg kg(-1) and C10: 10 mg kg(-1)) was investigated on liver gene expression by real-time PCR. Genes involved in mitochondrial metabolism, in antioxidant defences, detoxification and in DNA damage repair were studied. Metallothionein (MT) protein levels and Cd bioaccumulation were also investigated in liver, kidneys and muscle. Male ducks were subjected to three periods of exposure: 10, 20 and 40 days. Cd was mainly bioaccumulated in kidneys first and in liver. The concentrations in liver and kidneys appeared to reach a sta...
Source: Biometals - April 1, 2009 Category: Biochemistry Authors: Lucia M, Andre JM, Gonzalez P, Baudrimont M, Gontier K, Maury-Brachet R, Davail S Tags: Biometals Source Type: journals

Substrate role in the accumulation of heavy metals in sporocarps of wild fungi.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The distribution of neodymium, lead, thorium and uranium was investigated in about 100 samples of 12 different species of common, edible and non-edible mushrooms collected in unpolluted areas in the province of Ciudad Real, Central Spain. The quantitative analysis of heavy metals was performed by X-ray fluorescence spectrometry (a simple, accurate and non-destructive method). The concentration of these elements was related to three factors: mushroom specie, life style/substrate and study area. The results reveal considerable amounts of the four metals in all species analyzed as well as significant differences on the ca...
Source: Biometals - March 31, 2009 Category: Biochemistry Authors: Campos JA, Tejera NA, Sánchez CJ Tags: Biometals Source Type: journals

Cadmium-induced oxidative stress in two potato cultivars.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A hydroponic experiment was carried out to characterize the oxidative stress responses of two potato cultivars (Solanum tuberosum L. cvs. Asterix and Macaca) to cadmium (Cd). Plantlets were exposed to four Cd levels (0, 50, 100, 150 and 200 muM) for 7 days. Cd concentration was increased in both roots and shoot. Number of sprouts and roots was not decreased, whereas Cd treatment affected the number of nodal segments. Chlorophyll content and ALA-D activity were decreased in both cultivars, whereas carotenoids content was decreased only in Macaca. Cd caused lipid peroxidation in roots and shoot of both cultivars. Protein...
Source: Biometals - March 29, 2009 Category: Biochemistry Authors: Gonçalves JF, Tabaldi LA, Cargnelutti D, Pereira LB, Maldaner J, Becker AG, Rossato LV, Rauber R, Bagatini MD, Bisognin DA, Schetinger MR, Nicoloso FT Tags: Biometals Source Type: journals

Age-related changes in iron homeostasis in mouse ferroxidase mutants.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, We compared 1-year-old C57BL6/J mice on iron deficient, iron overload, or iron sufficient diets with two similarly aged genetic models of disturbed iron homeostasis, the sla (sex-linked anemia), and the ceruloplasmin knockout mice (Cp (-/-)) on iron sufficient diet. We found tissue specific changes in sla and nutritional iron deficiency including decreased liver Hamp1 expression and increased protein expression of the enterocyte basolateral iron transport components, hephaestin and ferroportin. In contrast, the Cp (-/-) mice did not show significantly increased Hamp1 expression despite increased liver iron s...
Source: Biometals - March 28, 2009 Category: Biochemistry Authors: Chen H, Attieh ZK, Gao H, Huang G, Su T, Ke W, Vulpe CD Tags: Biometals Source Type: journals

Characterization of feline serum ferritin-binding proteins: the presence of a novel ferritin-binding protein as an inhibitory factor in feline ferritin immunoassay.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Ferritin-binding proteins (FBPs) such as anti-ferritin antibody, alpha-2-macroglobulin, apolipoprotein B are expected to interact with circulating ferritin to eliminate it from circulation. However, we found that feline serum more strongly inhibits the detection of canine liver ferritin by immunoassay than its apoferritin; putative FBPs probably conceal ferritin epitopes detected by anti-ferritin antibodies. After complex formation between affinity-purified FBPs and canine liver ferritin, co-immunoprecipitates of the complex by anti-bovine spleen ferritin antibody were found to contain autoantibodies (IgG, IgM, and IgA...
Source: Biometals - March 27, 2009 Category: Biochemistry Authors: Sakamoto H, Kuboi T, Nagakura T, Hayashi S, Hoshi F, Mutoh K, Watanabe K, Orino K Tags: Biometals Source Type: journals