MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Biometals' source. Thu, 18 Mar 2010 16:19:32 +0100 http://www.medworm.com/index.php?rid=3360163&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20225068%26dopt%3DAbstract Authors: Taudte N, Grass G The ZIP (ZRT-, IRT-like Protein) protein ZupT from Escherichia coli is a transporter with a broad substrate range. Phenotypic and transport analysis showed that ZupT, in addition to Zn(II), Fe(II) and Co(II) uptake, is also involved in transport of Mn(II) and Cd(II). Competition experiments with other substrate cations suggested that ZupT has a slight preference for Zn(II) and kinetic parameters for Zn(II) in comparison to Co(II) and Mn(II) transport support this observation. Metal uptake into cells by ZupT was optimum at near neutral pH and inhibited by ionophores. Bicarbonate or other ions did not influence metal-uptake via ZupT. Amino acid residues of ZupT contributing to substrate specificity were identified by site directed mutagenesis. ZupT with a H89A ... Biometals journals http://www.medworm.com/rss/comments.php?id=3360163 Fri, 12 Mar 2010 00:00:00 +0100 3360163 http://www.medworm.com/index.php?rid=3360162&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20225069%26dopt%3DAbstract Authors: Ksheminska H, Honchar T, Usatenko Y, Gayda G, Gonchar M The paper describes the selection of chromate-resistant mutants of the yeast Pichia guilliermondii with a higher chromate-reducing activity and reports the EPR-study of Cr(V)-generation in the extra-cellular medium during the reduction of chromate by the yeast culture. It is shown that the reduction of chromate to Cr(III) species runs through the extra-cellular generation of Cr(V)-intermediate(s), thus supporting the assumption about the existence of an extra-cellular pathway of Cr(VI)-reduction. Furthermore, it is demonstrated that the chromate-resistance phenotype of tested mutants correlates with a lower stationary level of Cr(V)-species in the medium. It is thus suggested that isolated mutants can be used as sources o... Biometals journals http://www.medworm.com/rss/comments.php?id=3360162 Fri, 12 Mar 2010 00:00:00 +0100 3360162 http://www.medworm.com/index.php?rid=3360166&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20221787%26dopt%3DAbstract Authors: Teng CT This review focuses on the basic research that was performed on the lactoferrin protein and gene that was conducted in my laboratory over the past 25 years. This manuscript will outline how we discovered that lactoferrin is a target gene for estrogen, and how the first mouse lactoferrin cDNA, promoter and gene was cloned. Additionally, study was further extended to investigating the human lactoferrin protein and gene. Lastly the expression of lactoferrin in various tissues of both human and rodent under various physiological conditions were examined. PMID: 20221787 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=3360166 Thu, 11 Mar 2010 00:00:00 +0100 3360166 http://www.medworm.com/index.php?rid=3352904&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20217186%26dopt%3DAbstract This study investigated the effects of bovine lactoferrin (BLf) on the growth of different groups of bacteria in vitro. BLf showed a significant inhibitory effect on the growth of selected pathogens but not probiotics. BLf, in combination with probiotics, has the potential to influence the composition of the gut microflora via inhibition of intestinal pathogens with no significant effect on probiotic bacteria. PMID: 20217186 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=3352904 Tue, 09 Mar 2010 00:00:00 +0100 3352904 http://www.medworm.com/index.php?rid=3352906&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20213267%26dopt%3DAbstract Authors: Sandoval JM, Levêque P, Gallez B, Vásquez CC, Buc Calderon P Data regarding tellurium (Te) toxicity are scarce. Studies on its metabolism, performed mainly in bacteria, underline a major role of reactive oxygen species (ROS). We investigated whether tellurite undergoes redox cycling leading to ROS formation and cancer cell death. The murine hepatocarcinoma Transplantable Liver Tumor (TLT) cells were challenged with tellurite either in the presence or in the absence of different compounds as N-acetylcysteine (NAC), 3-methyladenine, BAPTA-AM, and catalase. NAC inhibition of tellurite-mediated toxicity suggested a major role of oxidative stress. Tellurite also decreased both glutathione (GSH) and ATP content by 57 and 80%, respectively. In the presence of NAC however, t... Biometals journals http://www.medworm.com/rss/comments.php?id=3352906 Mon, 08 Mar 2010 00:00:00 +0100 3352906 http://www.medworm.com/index.php?rid=3352905&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20213268%26dopt%3DAbstract Authors: Messner B, Bernhard D Today cardiovascular diseases (CVDs) are the killer number one world wide. In 2004 an estimated 17.1 million people died due to CVDs and this number will further increase to an estimated 23.6 million by 2030. Importantly, currently known risk factors, like hypertension, and hypercholesterolemia, can only be made responsible for about 50-75% of all CVDs, highlighting the urgent need to search for and define new CVD risk factors. Cadmium (Cd) was shown to have the potential to serve as one such novel risk factor, as it was demonstrated-in vitro, in animal studies, and in human studies-that Cd causes atherosclerosis (the basis of most CVDs). Herein, we discuss the molecular and cellular biological effects of Cd in the cardiovascular system; we present concep... Biometals journals http://www.medworm.com/rss/comments.php?id=3352905 Sun, 07 Mar 2010 00:00:00 +0100 3352905 http://www.medworm.com/index.php?rid=3346851&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20204475%26dopt%3DAbstract Authors: Thévenod F Cadmium (Cd(2+)) is a nonessential divalent metal ion that causes toxicity in multiple organs in humans. In order for toxicity to occur Cd(2+) must first enter cells by utilizing transport pathways for essential metals. This review focuses on studies in which Cd(2+) transport was directly demonstrated by electrophysiological, radiotracer or Cd(2+)-sensitive fluorescent dye techniques. The chemistry of Cd(2+) and metal ions in general is addressed in the context of properties relevant for transport through membrane proteins, such as hydration energy. Apart from transport by the ZIP transporters SLC39A8 and SLC39A14, which is not topic of the review, uptake of free Cd(2+) has been demonstrated for the Fe(2+)/H(+) cotransporter divalent metal transporter 1. Moreov... Biometals journals http://www.medworm.com/rss/comments.php?id=3346851 Fri, 05 Mar 2010 00:00:00 +0100 3346851 http://www.medworm.com/index.php?rid=3346850&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20204476%26dopt%3DAbstract Authors: Gilch S, Meyer O, Schmidt I Soluble ammonia monooxygenase (AMO) from Nitrosomonas europaea was purified to homogeneity and metals in the active sites of the enzyme (Cu, Fe) were analyzed by electron paramagnetic resonance (EPR) spectroscopy. EPR spectra were obtained for a type 2 Cu(II) site with g(||) = 2.24, A(||) = 18.4 mT and g( perpendicular) = 2.057 as well as for heme and non heme iron present in purified soluble AMO from N. europaea. A second type 2 Cu(II) EPR signal with g(||) = 2.29, A(||) = 16.1 mT and g( perpendicular) = 2.03 appeared in the spectrum of the ferricyanide oxidized enzyme and was attributed to oxidation of cuprous sites. Comparison of EPR-detectable Cu(2+) with total copper determined by inductively coupled plasma-mass spectrometry (ICP-MS) suggests t... Biometals journals http://www.medworm.com/rss/comments.php?id=3346850 Fri, 05 Mar 2010 00:00:00 +0100 3346850 http://www.medworm.com/index.php?rid=3335902&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20195886%26dopt%3DAbstract Authors: Shimazaki KI, Kushida T Lactoferrin is a multi-functional metal-binding glycoprotein that exhibits many biological functions of interest to many researchers from the fields of clinical medicine, dentistry, pharmacology, veterinary medicine, nutrition and milk science. To date, a number of academic reports concerning the biological activities of lactoferrin have been published and are easily accessible through public data repositories. However, as the literature is expanding daily, this presents challenges in understanding the larger picture of lactoferrin function and mechanisms. In order to overcome the "analysis paralysis" associated with lactoferrin information, we attempted to apply a text mining method to the accumulated lactoferrin literature. To this end, we used the in... Biometals journals http://www.medworm.com/rss/comments.php?id=3335902 Tue, 02 Mar 2010 00:00:00 +0100 3335902 http://www.medworm.com/index.php?rid=3335901&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20195887%26dopt%3DAbstract In conclusion, results show that LFchimera, LF and peptides have potential as bactericidal agents in the antibiotic-resistant strains of S. aureus and E. coli and also the work strongly suggest that LFcin17-30 and LFampin265-284 acts synergistically with antibiotics against multidrug resistant EPEC and MRSA in vitro. PMID: 20195887 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=3335901 Tue, 02 Mar 2010 00:00:00 +0100 3335901 http://www.medworm.com/index.php?rid=3335905&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20191306%26dopt%3DAbstract This study sets out to compare the absorption and toxicity of Cadmium (Cd) administered via the food-chain and inorganic Cd administered in drinking water after 1 and 3 months exposure using rats as animal model. The food-chain was mimicked by exposing rats to diet containing Cd pre-exposed fish. The uptake of Cd by the rats after both mode of exposure was calculated by summing up the Cd burden in the liver and kidneys and was expressed in terms of % intake. The toxicity of Cd was assessed by monitoring biochemical indices of liver function in the plasma and liver. Regardless of the mode of exposure of the rats, the Cd load in the liver and kidney was significantly (P < 0.05) higher than the respective controls with the kidney having a significantly higher load than the liver after both... Biometals journals http://www.medworm.com/rss/comments.php?id=3335905 Sat, 27 Feb 2010 00:00:00 +0100 3335905 http://www.medworm.com/index.php?rid=3335904&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20191307%26dopt%3DAbstract Authors: Roseanu A, Florian PE, Moisei M, Sima LE, Evans RW, Trif M A number of studies have reported the anti-tumoral activity of lactoferrin, a property mediated by a variety of mechanisms such as inhibitory effects on tumor cell growth, NK cell activation, and enhancement of apoptosis. Liposomes are known to be an efficient drug delivery system which can enhance the therapeutic potential of the encapsulated compounds. We have used positively charged liposomes composed of phosphatidylcholine (PC), dioleoylphosphatidylethanolamine (DOPE), cholesterol (Chol) and stearylamine (SA) (6:1:2:1 M ratio) as a carrier system for bovine iron-free Lf (ApoBLf), and compared the in vitro effect of free and liposome-entrapped ApoBLf on the growth and morphology of murine melanoma B16-F10 cells. Lip... Biometals journals http://www.medworm.com/rss/comments.php?id=3335904 Sat, 27 Feb 2010 00:00:00 +0100 3335904 http://www.medworm.com/index.php?rid=3335903&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20191308%26dopt%3DAbstract Authors: Puddu P, Latorre D, Valenti P, Gessani S Lactoferrin (Lf) is a mammalian exclusive protein widely distributed in milk and exocrine secretions exhibiting multifunctional properties. Many of the proven or proposed functions of Lf, apart from its iron binding activity, depend on its capacity to bind to other macromolecules. Lf can bind and sequester lipopolysaccharide (LPS), thus preventing pro-inflammatory pathway activation, sepsis and tissue damage. However, the interplay between Lf and LPS is complex, and may result in different outcomes, including both suppression of the inflammatory response and immune activation. These findings are critically relevant in the development of Lf-based therapeutic interventions in humans. Understanding the molecular basis and functional conseq... Biometals journals http://www.medworm.com/rss/comments.php?id=3335903 Sat, 27 Feb 2010 00:00:00 +0100 3335903 http://www.medworm.com/index.php?rid=3291162&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20165903%26dopt%3DAbstract Authors: Wang J, Tian Z This is a short preface of this Special Issue Lactoferrin, it described the major points of key reporters in 'The 9th International Conference on LF Structure, Function and Applications' in Beijing in late Autumn 2009, and the major articles published in this issue. A panaroma and the lastest advances of lactoferrin R&D during past two years (2007-2009) was tried to extract. PMID: 20165903 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=3291162 Thu, 18 Feb 2010 00:00:00 +0100 3291162 http://www.medworm.com/index.php?rid=3284370&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20157763%26dopt%3DAbstract Authors: Tian H, Maddox IS, Ferguson LR, Shu Q Lactoferrin is an iron-binding glycoprotein that exhibits a range of health benefits including immune regulation and disease prevention derived from its structural properties. The present study employed immune cell models and a colon epithelial cell model to investigate the protective effects of bovine lactoferrin (BLf) on both immune cells and colon epithelium cells. BLf caused significant reduction of faecal genotoxin-induced DNA damage in HT29 cells, and down-regulation of lipopolysaccharide (LPS)-induced macrophage cell stress and endotoxic response, in an infection status. PMID: 20157763 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=3284370 Tue, 16 Feb 2010 00:00:00 +0100 3284370 http://www.medworm.com/index.php?rid=3276520&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20155437%26dopt%3DAbstract In this study, we confirmed that Lf/DeltaLf Taqman gene expression assay is a powerful tool to investigate the expression of both Lf and DeltaLf transcripts. We also showed that lymphocytes and leukocytes isolated from fresh human blood expressed an extremely high level of DeltaLf messengers. An extensive series of cancer cell lines has been studied confirming that both P1 and P2 promoter regions of the Lf gene are downregulated or silenced in the case of cancer. Furthermore, using stimulation by bacterial lipopolysaccharides (LPS), we showed that in MDA-MB-231 and HT-29 epithelial cells, Lf expression is strongly increased with a higher expression level in MDA-MB-231 whereas DeltaLf expression is not. These results suggest that the NF-kappaB/cRel response elements present in the P1 promot... Biometals journals http://www.medworm.com/rss/comments.php?id=3276520 Sun, 14 Feb 2010 00:00:00 +0100 3276520 http://www.medworm.com/index.php?rid=3276519&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20155438%26dopt%3DAbstract Authors: Wakabayashi H, Kondo I, Kobayashi T, Yamauchi K, Toida T, Iwatsuki K, Yoshie H Lactoferrin (LF) is a component of saliva and is suspected to be a defense factor against oral pathogens including Streptococcus mutans and Candida albicans. Periodontitis is a very common oral disease caused by periodontopathic bacteria. Antimicrobial activities and other biological effects of LF against representative periodontopathic bacteria, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia, have been widely studied. Association of polymorphisms in LF with incidence of aggressive periodontitis and the role of LF in the gingival crevicular fluid as a marker of periodontitis severity have also been reported. Periodontopathic bacteria reside as a biofilm in... Biometals journals http://www.medworm.com/rss/comments.php?id=3276519 Sun, 14 Feb 2010 00:00:00 +0100 3276519 http://www.medworm.com/index.php?rid=3276521&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20155302%26dopt%3DAbstract Authors: Beddek AJ, Schryvers AB Bacteria that inhabit the respiratory and genitourinary tracts of mammals encounter an iron-deficient environment on the mucosal surface where iron is complexed by the host iron-binding proteins transferrin and lactoferrin. Lactoferrin is also present in high concentrations at sites of inflammation where the cationic anti-microbial peptide lactoferricin is produced by proteolysis of lactoferrin. Several members of the Neisseriaceae and Moraxellaceae families express surface receptors, capable of specifically binding host lactoferrin and extracting the iron from lactoferrin as a source of iron for growth. The receptor is comprised of an integral outer membrane protein, lactoferrin binding protein A (LbpA), and a largely exposed surface lipoprotein, lacto... Biometals journals http://www.medworm.com/rss/comments.php?id=3276521 Sat, 13 Feb 2010 00:00:00 +0100 3276521 http://www.medworm.com/index.php?rid=3267652&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20151177%26dopt%3DAbstract We report that treatment of cervical tumor Hep-2 cells with zinc pyrithione leads to an early appearance of cytoplasmic zinc-specific foci with corresponding accumulation of zinc first in mitochondria and later in lysosomes. Concomitant with these changes, upregulation of expression of metallothionein II A gene as well as the increased abundance of its protein occurs. Moreover, zinc activates p53 and its dependent genes including Puma and Bax and they contribute to an observed loss of mitochondrial membrane potential and activation of apoptosis. Conversely, lysosomal membrane permeabilization and its promoted cleavage of Bid occurs in a delayed manner in treated cells and their effect on decrease of mitochondrial membrane potential is limited. The use of specific inhibitors as well as siRN... Biometals journals http://www.medworm.com/rss/comments.php?id=3267652 Fri, 12 Feb 2010 00:00:00 +0100 3267652 http://www.medworm.com/index.php?rid=3267653&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20148305%26dopt%3DAbstract In this study, Lactobacillus casei was used to deliver and express human lactoferrin (hLF) to protect the host against bacterial infection. Full-length hLF cDNA was cloned into a Lactobacillus-specific plasmid to produce the L. casei transformants (rhLF/L. casei). Antimicrobial activity of recombinant hLF was examined in inhibition of bacteria growth in vitro. A mouse model was established to test in vivo antibacterial activity and protective effect of orally-administered probiotic L. casei transformant in the gastrointestinal tract. Trials were conducted in which animals were challenged with E. coli ATCC25922. E. coli colony numbers in duodenal fluid from the group fed with rhLF/L. casei were significantly lower than those of the group fed with wild-type L. casei or placebo (P < 0.01).... Biometals journals http://www.medworm.com/rss/comments.php?id=3267653 Thu, 11 Feb 2010 00:00:00 +0100 3267653 http://www.medworm.com/index.php?rid=3267654&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20145976%26dopt%3DAbstract Authors: Bai X, Teng D, Tian Z, Zhu Y, Yang Y, Wang J The investigation of the recombinant bovine lactoferrin-derived antimicrobial protein (rBLfA) demonstrates that the inter-lobe region of bovine lactoferrin contributes to iron binding stability and antimicrobial activity against Staphylococcus aureus. rBLfA containing N-lobe (amino acid residues 1-333) and inter-lobe region (residues 334-344) was expressed in Pichia pastoris at shaking flask and fermentor level. The recombinant intact bovine lactoferrin (rBLf) and N-lobe (rBLfN) were expressed in the same system as control. The physical-chemical parameters of rBLfA, rBLfN and rBLf including amino acid residues, molecular weight, isoelectric point, net positive charge and instability index were computed and compared. The simulated te... Biometals journals http://www.medworm.com/rss/comments.php?id=3267654 Wed, 10 Feb 2010 00:00:00 +0100 3267654 http://www.medworm.com/index.php?rid=3267655&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20143251%26dopt%3DAbstract Authors: Legrand D, Mazurier J Lactoferrin (Lf) is an essential element of innate immunity, which refers to antigen-nonspecific defense mechanisms that a host uses immediately or within hours after exposure to an antigen. Following infection, Lf is released from neutrophils (PMNs) in blood and inflamed tissues and, such as other soluble pattern-recognition receptors of the innate immunity, Lf recognizes unique microbial molecules called pathogen-associated molecular patterns (PAMPs): LPS from the gram-negative cell wall and bacterial unmethylated CpG DNA. However, unlike classical PAMPs receptors involved in the activation of immune cells, Lf may act either as a competitor for these receptors or as a partner molecule, depending on the physiological status of the organism. These immunom... Biometals journals http://www.medworm.com/rss/comments.php?id=3267655 Tue, 09 Feb 2010 00:00:00 +0100 3267655 http://www.medworm.com/index.php?rid=3254777&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20140481%26dopt%3DAbstract Authors: López-Soto F, León-Sicairos N, Nazmi K, Bolscher JG, de la Garza M Entamoeba histolytica is a parasitic protozoan that produces amoebiasis, an intestinal disease characterized by ulcerative colitis and dysentery. In some cases, trophozoites can travel to the liver leading to hepatic abscesses and death. Recently, lactoferrin and lactoferricin B have been shown to be amoebicidal in axenic cultures. The aim of this work was to determine whether the lactoferrin-peptides lactoferricin amino acids 17-30, lactoferrampin amino acids 265-284, and lactoferrin chimera which is a fusion product of the two peptides, are capable of producing a microbicidal effect to trophozoites of E. histolytica. We evaluated the killing effect of these peptides in growth kinetics carried out in... Biometals journals http://www.medworm.com/rss/comments.php?id=3254777 Sat, 06 Feb 2010 00:00:00 +0100 3254777 http://www.medworm.com/index.php?rid=3248808&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20135339%26dopt%3DAbstract Authors: Otero LH, Beassoni PR, Lisa AT, Domenech CE Pseudomonas aeruginosa phosphorylcholine phosphatase (PchP) catalyzes the hydrolysis of phosphorylcholine, which is produced by the action of hemolytic phospholipase C on phosphatidylcholine or sphyngomielin, to generate choline and inorganic phosphate. Among divalent cations, its activity is dependent on Mg(2+) or Zn(2+). Mg(2+) produced identical activation at pH 5.0 and 7.4, but Zn(2+) was an activator at pH 5.0 and became an inhibitor at pH 7.4. At this higher pH, very low concentrations of Zn(2+) inhibited enzymatic activity even in the presence of saturating Mg(2+) concentrations. Considering experimental and theoretical physicochemical calculations performed by different authors, we conclude that at pH 5.0, Mg(2+) and Zn(2+) a... Biometals journals http://www.medworm.com/rss/comments.php?id=3248808 Fri, 05 Feb 2010 00:00:00 +0100 3248808 http://www.medworm.com/index.php?rid=3244403&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20130962%26dopt%3DAbstract Authors: Kitamura M, Hiramatsu N Cadmium preferentially accumulates in the kidney, the major target for cadmium-related toxicity. Several underlying mechanisms are postulated, and reactive oxygen species (ROS) have been considered as crucial mediators for tissue injuries. In addition to oxidative stress, we recently disclosed that endoplasmic reticulum (ER) stress also plays a critical role. Cadmium causes ER stress in vitro and in vivo and mediates induction of apoptosis in target tissues. In this article, we describe a role for ER stress and involvement of particular branches of the unfolded protein response (UPR) in cadmium-triggered tissue injury, especially nephrotoxicity. We also discuss relationship between oxidative stress and ER stress, and involvement of selective ROS in the ... Biometals journals http://www.medworm.com/rss/comments.php?id=3244403 Thu, 04 Feb 2010 00:00:00 +0100 3244403 http://www.medworm.com/index.php?rid=3244402&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20130963%26dopt%3DAbstract Authors: Wang J, Tian Z, Teng D, Yang Y, Hu J, Wang J The lactoferrin cDNA of Kunming mice was isolated by reverse transcription polymerase chain reaction and cloned into vector pET28a(+). Its deduced amino acid sequence was analyzed and compared with lactoferrin of other species. Its secondary and tertiary structure are predicted and modeled by bioinformatics tools online. Then recombinant Kunming mice lactoferrin and its N-lobe were both expressed successfully in the Escherichia coli BL21(DE3) in the form of inclusion bodies. After purification with Ni-NTA His-Bind resin, the yield of recombinant lactoferrin was 17 mg l(-1) with purity of 92.1%, and that of lactoferrin N-lobe was 20 mg l(-1) with purity of 98.5%. The inhibition efficiency of refolded lactoferrin N-lobe against Staphy... Biometals journals http://www.medworm.com/rss/comments.php?id=3244402 Thu, 04 Feb 2010 00:00:00 +0100 3244402 http://www.medworm.com/index.php?rid=3244404&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20127392%26dopt%3DAbstract Authors: Fonteh PN, Keter FK, Meyer D Highly active antiretroviral therapy (HAART) has resulted in decreased mortality and morbidity from the acquired immune deficiency syndrome caused by the human immunodeficiency virus (HIV). Drug resistance and toxicity of HAART has led to the search for novel inhibitors of HIV infection. Gold-based compounds have shown promising activity against a wide range of clinical conditions and microorganism infections including HIV-1. A typical example is auranofin which resulted in an elevated CD4+ T-cell count in an HIV patient being treated for psoriatic arthritis. In addition, reports exist on gold-based inhibitors of reverse transcriptase (RT), protease (PR) and viral entry of host cells. These and other characteristics of gold-based HIV drugs are revi... Biometals journals http://www.medworm.com/rss/comments.php?id=3244404 Wed, 03 Feb 2010 00:00:00 +0100 3244404 http://www.medworm.com/index.php?rid=3223833&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20112049%26dopt%3DAbstract This study describes various biochemical processes involved in the mitigation of cadmium toxicity in green alga Ulva lactuca. The plants when exposed to 0.4 mM CdCl(2) for 4 days showed twofold increase in lipoperoxides and H(2)O(2) content that collectively decreased the growth and photosynthetic pigments by almost 30% over the control. The activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione peroxidase (GPX) enhanced by twofold to threefold and that of catalase (CAT) diminished. Further, the isoforms of these enzymes, namely, Mn-SOD (~85 kDa), GR (~180 kDa) and GPX (~50 kDa) responded specifically to Cd(2+) exposure. Moreover, the contents of reduced glutathione (3.01 fold) and ascorbate (1.85 fold) a... Biometals journals http://www.medworm.com/rss/comments.php?id=3223833 Sat, 30 Jan 2010 00:00:00 +0100 3223833 http://www.medworm.com/index.php?rid=3217440&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20107868%26dopt%3DAbstract In this study we examined the effect of a low dose of Cd (7.5 mug/day) on 24-h changes in expression of redox pathway enzyme and circadian genes in rat medial basal hypothalamus (MBH). Rats receiving CdCl(2) (5 ppm in drinking water) or tap water for 1 month were killed at six different time intervals throughout a 24 h cycle. MBH mRNA levels were measured by real-time PCR analysis. In CdCl(2) treated rats a disruption of 24-h pattern of hypothalamic gene expression of nitric oxide synthase (NOS)-1 and -2, heme oxygenase (HO)-1 and -2, Mn- superoxide dismutase (SOD), catalase, glutathione peroxidase and glutathione reductase was detectable. Mean levels of MBH mRNA for HO-2, Mn-SOD and catalase augmented after Cd intake, whereas those of NOS-2 decreased. After CdCl(2) intake rats the 24-h pa... Biometals journals http://www.medworm.com/rss/comments.php?id=3217440 Wed, 27 Jan 2010 00:00:00 +0100 3217440 http://www.medworm.com/index.php?rid=3217439&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20107869%26dopt%3DAbstract Authors: Prozialeck WC, Edwards JR As the risks of cadmium (Cd)-induced kidney disease have become increasingly apparent, much attention has been focused on the development and use of sensitive biomarkers of Cd nephrotoxicity. The purpose of this review is to briefly summarize the current state of Cd biomarker research. The review includes overviews of the toxicokinetics of Cd, the mechanisms of Cd-induced proximal tubule injury, and mechanistic summaries of some of the biomarkers (N-acetyl-beta-D: -glucosamidase; beta(2)-microglubulin, metallothionein, etc.) that have been most widely used in monitoring of human populations for Cd exposure and nephrotoxicity. In addition, several novel biomarkers (kidney injury molecule-1, alpha-glutathione-S-transferase and insulin) that offer the po... Biometals journals http://www.medworm.com/rss/comments.php?id=3217439 Wed, 27 Jan 2010 00:00:00 +0100 3217439 http://www.medworm.com/index.php?rid=3200862&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20094900%26dopt%3DAbstract In this study, we investigated the effects of bovine lactoferrin on the chondrogenic differentiation of ATDC5 chondroprogenitor cells. This mouse embryonic carcinoma-derived clonal cell line provides an in vitro model of chondrogenesis. Lactoferrin treatment of differentiating ATDC5 cells promoted cell proliferation in the initial stage of the differentiation process. However, lactoferrin treatment resulted in inhibition of hypertrophic differentiation, characterized by suppression of alkaline phosphatase activity, aggrecan synthesis and N-cadherin expression. This inhibitory effect was accompanied by sustained Sox9 expression, as well as increased Smad2/3 expression and phosphorylation, suggesting that lactoferrin regulates chondrogenic differentiation by up-regulating the Smad2/3-Sox9 si... Biometals journals http://www.medworm.com/rss/comments.php?id=3200862 Fri, 22 Jan 2010 00:00:00 +0100 3200862 http://www.medworm.com/index.php?rid=3164050&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20063044%26dopt%3DAbstract Authors: Calgaroto NS, Castro GY, Cargnelutti D, Pereira LB, Gonçalves JF, Rossato LV, Antes FG, Dressler VL, Flores EM, Schetinger MR, Nicoloso FT Oxidative stress caused by mercury (Hg) was investigated in Pfaffia glomerata plantlets grown in nutrient solution using sand as substrate. Thirty-day-old acclimated plants were treated for 9 days with four Hg levels (0, 1, 25 and 50 muM) in the substrate. Parameters such as growth, tissue Hg concentration, toxicity indicators (delta-aminolevulinic acid dehidratase, delta-ALA-D, activity), oxidative damage markers (TBARS, lipid peroxidation, and H(2)O(2) concentration) and enzymatic (superoxide dismutase, SOD, catalase, CAT, and ascorbate peroxidase, APX) and non-enzymatic (non-protein thiols, NPSH, ascorbic acid, AsA, and proline conc... Biometals journals http://www.medworm.com/rss/comments.php?id=3164050 Sat, 09 Jan 2010 00:00:00 +0100 3164050 http://www.medworm.com/index.php?rid=3146647&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20049509%26dopt%3DAbstract Authors: Forman S, Paulley JT, Fetherston JD, Cheng YQ, Perry RD Although Yersinia pestis epidemic biovars and Yersinia pseudotuberculosis are recently diverged, highly related species, they cause different diseases via disparate transmission routes. Since iron transport systems are important for iron acquisition from hosts and for survival in the environment, we have analyzed potential iron transport systems encoded by epidemic and non-epidemic or endemic strains of Y. pestis as well as two virulent Y. pseudotuberculosis strains. Computational biology analysis of these genomes showed a high degree of identity/similarity among 16 proven or possible iron/heme transporters identified. Of these, 7 systems were essentially the same in all seven genomes analyzed. The remaining 9 loci had 2-... Biometals journals http://www.medworm.com/rss/comments.php?id=3146647 Tue, 05 Jan 2010 00:00:00 +0100 3146647 http://www.medworm.com/index.php?rid=3104472&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20012769%26dopt%3DAbstract Authors: Wang Y, Zhang X, Zhang Q, Yang Z The oxidative DNA damage by copper (II) complexes in the presence of chlorogenic acid was explored using agarose gel electrophoresis. The extent of pBR322 DNA damage was enhanced significantly with increasing concentration of [Cu-phen-Thr] complex and incubation time. A fluorescence quenching activity of calf thymus DNA-EB was observed more remarkably with chlorogenic acid than without chlorogenic acid. The fluorescence measurements suggested that [Cu-phen-Thr] complex not only can bind to DNA by intercalation but also can damage the double strand DNA in the presence of chlorogenic acid. Further, 8-hydroxy-2'-deoxyguanosine, a biomarker of DNA oxidative damage was determined by electrochemical method. The control experiments revealed that the s... Biometals journals http://www.medworm.com/rss/comments.php?id=3104472 Sat, 12 Dec 2009 00:00:00 +0100 3104472 http://www.medworm.com/index.php?rid=3104473&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20012553%26dopt%3DAbstract Authors: Urquiza NM, Manca SG, Moyano MA, Dellmans RA, Lezama L, Rojo T, Naso LG, Williams PA, Ferrer EG Methimazole (MeimzH) is an anti-thyroid drug and the first choice for patients with Grave's disease. Two new copper(II) complexes of this drug: [Cu(MeimzH)(2)(NO(3))(2)].0.5H(2)O and [Cu(MeimzH)(2)(H(2)O)(2)](NO(3))(2).H(2)O were synthesized and characterized by elemental analysis, dissolution behavior, thermogravimetric analysis and UV-vis, diffuse reflectance, FTIR and EPR spectroscopies. As it is known that copper(II) cation can act as an inhibitor of alkaline phosphatase (ALP), the inhibitory effect of methimazole and its copper(II) complexes on ALP activity has also been investigated. PMID: 20012553 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=3104473 Fri, 11 Dec 2009 00:00:00 +0100 3104473 http://www.medworm.com/index.php?rid=3104474&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20012160%26dopt%3DAbstract Authors: Reddy SY, Pullakhandam R, Dinesh Kumar B Lead (Pb) toxicity has been a serious concern in industrialized societies because of its association with functional deficits in nervous, haematopoietic and renal systems. Several studies have shown beneficial effects of thiamine on Pb toxicity. It is speculated that Pb chelation by thiamine may be a possible mechanism. However, the exact nature of these interactions remained elusive. In the present study we have characterized the interaction of Pb with thiamine using UV-Vis as well as fluorescence spectroscopic methods and studied the effect of thiamine treatment on blood and tissue Pb levels during simultaneous or post-exposure to Pb in rat model. The spectroscopic studies revealed that Pb interacts with the pyrimidine ring of thiamin... Biometals journals http://www.medworm.com/rss/comments.php?id=3104474 Thu, 10 Dec 2009 00:00:00 +0100 3104474 http://www.medworm.com/index.php?rid=3080059&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19997770%26dopt%3DAbstract Authors: Gaboriau F, Leray AM, Ropert M, Gouffier L, Cannie I, Troadec MB, Loréal O, Brissot P, Lescoat G Two oral chelators, CP20 (deferiprone) and ICL670 (deferasirox), have been synthesized for the purpose of treating iron overload diseases, especially thalassemias. Given their antiproliferative effects resulting from the essential role played by iron in cell processes, such compounds might also be useful as anticancer agents. In the present study, we tested the impact of these two iron chelators on iron metabolism, in the HepaRG cell line which allowed us to study proliferating and differentiated hepatocytes. ICL670 uptake was greater than the CP20 uptake. The iron depletion induced by ICL670 in differentiated cells increased soluble transferrin receptor expression, decreased ... Biometals journals http://www.medworm.com/rss/comments.php?id=3080059 Tue, 08 Dec 2009 00:00:00 +0100 3080059 http://www.medworm.com/index.php?rid=3031135&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19937462%26dopt%3DAbstract Authors: Walton RC, White KN, Livens F, McCrohan CR Aluminum is a toxic metal whose complex aquatic chemistry, mechanisms of toxicity and trophic transfer are not fully understood. The only isotope of Al suitable for tracing experiments in organisms-(26)Al-is a rare, costly radioisotope with a low emission energy, making its use difficult. Gallium shares a similar chemistry with Al and was therefore investigated as a potential substitute for Al for use in aquatic organisms. The freshwater snail, Lymnaea stagnalis was exposed to either Al or Ga (0.0135 mM) under identical conditions for up to 40 days. Behavioural toxicity, metal accumulation in the tissues, and sub-cellular partitioning of the metals were determined. Al was more toxic than Ga and accumulated to significantly higher leve... Biometals journals http://www.medworm.com/rss/comments.php?id=3031135 Wed, 25 Nov 2009 00:00:00 +0100 3031135 http://www.medworm.com/index.php?rid=3031137&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19936941%26dopt%3DAbstract Authors: Mrak T, Jeran Z, Batič F, Sanità di Toppi L Thalli of epiphytic lichen Hypogymnia physodes (L.) Nyl. and terricolous Cladonia furcata (Huds.) Schrad., collected from an area with background arsenic concentrations, were exposed to 0, 0.1, 1 and 10 mug mL(-1) arsenate (As(V)) solutions for 24 h. After exposure they were kept in the metabolically active state for 0, 24 and 48 h in a growth chamber. In the freeze dried samples glutathione (GSH), glutathione disulphide (GSSG), cysteine (Cys) and cystine were analysed and induction of phytochelatin (PC) synthesis measured by reversed-phase high-performance liquid chromatography in combination with fluorescence detection or UV spectrometry. Total arsenic content in thalli was measured by instrumental neutron activation ana... Biometals journals http://www.medworm.com/rss/comments.php?id=3031137 Sat, 21 Nov 2009 00:00:00 +0100 3031137 http://www.medworm.com/index.php?rid=3031136&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19936942%26dopt%3DAbstract Authors: Bhalla P, Singla N, Dhawan DK The present study was aimed to explore the potential of an antidepressant drug lithium (Li) in reducing aluminium (Al) induced neurotoxicity. To carry out the investigations, Al was administered orally (100 mg AlCl(3)/Kg b wt/day) whereas, Li was administered through diet (1.1 g Li(2)CO(3)/Kg diet, daily) for a total duration of 2 months. Al treatment resulted in a significant increase in the activity of enzyme nitric oxide synthase and the levels of L: -citrulline which, however, were decreased appreciably following lithium supplementation. Al treatment also revealed an increase in DNA fragmentation as evidenced by an increase in number of comets. Interestingly, Li supplementation to Al treated rats reduced the damage inflicted on DNA by Al. Ultr... Biometals journals http://www.medworm.com/rss/comments.php?id=3031136 Sat, 21 Nov 2009 00:00:00 +0100 3031136 http://www.medworm.com/index.php?rid=3000422&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19915997%26dopt%3DAbstract Authors: Asatiani N, Abuladze M, Kartvelishvili T, Kulikova N, Asanishvili L, Holman HY, Sapojnikova N 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 time. The activity of GPx (glutathione peroxidase) is proposed as a ... Biometals journals http://www.medworm.com/rss/comments.php?id=3000422 Sun, 15 Nov 2009 00:00:00 +0100 3000422 http://www.medworm.com/index.php?rid=3000423&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19911117%26dopt%3DAbstract 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 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 whic... Biometals journals http://www.medworm.com/rss/comments.php?id=3000423 Fri, 13 Nov 2009 00:00:00 +0100 3000423 http://www.medworm.com/index.php?rid=2972162&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19894125%26dopt%3DAbstract 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) Biometals journals http://www.medworm.com/rss/comments.php?id=2972162 Fri, 06 Nov 2009 00:00:00 +0100 2972162 http://www.medworm.com/index.php?rid=2972161&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19894126%26dopt%3DAbstract Authors: Calderoni AM, Biaggio V, Acosta M, Oliveros L, Mohamed F, Giménez MS 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). Cultured PAL cells were stained with Hoechst 33258 to determine the presence of alterations ... Biometals journals http://www.medworm.com/rss/comments.php?id=2972161 Fri, 06 Nov 2009 00:00:00 +0100 2972161 http://www.medworm.com/index.php?rid=2967963&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19890726%26dopt%3DAbstract 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 quite different from those of the re-HDT. These data suggest that the re-HDT may have two Zn(2+)-binding sites, one is an intrinsic or tight-binding site (zinc-alpha) es... Biometals journals http://www.medworm.com/rss/comments.php?id=2967963 Thu, 05 Nov 2009 00:00:00 +0100 2967963 http://www.medworm.com/index.php?rid=2881452&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19816776%26dopt%3DAbstract Authors: Wilson MK, Abergel RJ, Arceneaux JE, Raymond KN, Byers BR 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, suggesting that the production of PB and BB responded to the host temperature signal. The dual siderophores of... Biometals journals http://www.medworm.com/rss/comments.php?id=2881452 Thu, 08 Oct 2009 23:00:00 +0100 2881452 http://www.medworm.com/index.php?rid=2863038&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19802720%26dopt%3DAbstract 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 mechanisms of these arsenic species are not exactly the same. Reagents such as FCCP, valinomycin and nigericin that dissipate transmembrane proton potential or change the... Biometals journals http://www.medworm.com/rss/comments.php?id=2863038 Sat, 03 Oct 2009 23:00:00 +0100 2863038 http://www.medworm.com/index.php?rid=2846834&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19787298%26dopt%3DAbstract Authors: Seng HL, Von ST, Tan KW, Maah MJ, Ng SW, Rahman RN, Caracelli I, Ng CH 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 analysis of its interaction with various duplex polynucleotides reveals its binding mode as ma... Biometals journals http://www.medworm.com/rss/comments.php?id=2846834 Mon, 28 Sep 2009 23:00:00 +0100 2846834 http://www.medworm.com/index.php?rid=2821306&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19768661%26dopt%3DAbstract Authors: Wiseman DA, Sharma S, Black SM 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, indicating Zn(2+)-dependent mechanisms in this process. However, the molecular mechanisms of Zn(2+)-mediated mitochondrial dysfunction ar... Biometals journals http://www.medworm.com/rss/comments.php?id=2821306 Mon, 21 Sep 2009 23:00:00 +0100 2821306 http://www.medworm.com/index.php?rid=2821307&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19768636%26dopt%3DAbstract Authors: Pantcheva IN, Zhorova R, Mitewa M, Simova S, Mayer-Figge H, Sheldrick WS 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)].5MeCN (1) and [Ca(Mon)(2)(H(2)O)(2)].H(2)O.5MeCN (2) in the monoclinic P21 space group. T... Biometals journals http://www.medworm.com/rss/comments.php?id=2821307 Sun, 20 Sep 2009 23:00:00 +0100 2821307 http://www.medworm.com/index.php?rid=2821309&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19768555%26dopt%3DAbstract Authors: Jonsson CM, Aoyama H 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 0.37 mM, and activation energy values of 26.8 and 13.6 kJ mol(-1) were determined in the absence and in the presence of 0.2 mM Cu(2+), respec... Biometals journals http://www.medworm.com/rss/comments.php?id=2821309 Fri, 18 Sep 2009 23:00:00 +0100 2821309 http://www.medworm.com/index.php?rid=2821308&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19768556%26dopt%3DAbstract Authors: Civelek S, Gelişgen R, Andican G, Seven A, Küçük SH, Ozdoğan M, Burçak G 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 period, glucose(mg/dl), Cu(mug/dl), TBARS(mumol/l), TAO... Biometals journals http://www.medworm.com/rss/comments.php?id=2821308 Fri, 18 Sep 2009 23:00:00 +0100 2821308 http://www.medworm.com/index.php?rid=2810058&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19760107%26dopt%3DAbstract Authors: Song Y, Elias V, Wong CP, Scrimgeour AG, Ho E 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 were given either zinc-adequate (ZA, 30 mg Zn/kg) or marginal zinc-deficient (MZD, 5 mg Zn/kg) diet for 9 weeks. In... Biometals journals http://www.medworm.com/rss/comments.php?id=2810058 Wed, 16 Sep 2009 23:00:00 +0100 2810058 http://www.medworm.com/index.php?rid=2810057&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19760108%26dopt%3DAbstract Authors: Freitas M, Porto G, Lima JL, Fernandes E 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 purpose, different detection methods and incubation media were used. The obtained results showed that phosphate buffers... Biometals journals http://www.medworm.com/rss/comments.php?id=2810057 Wed, 16 Sep 2009 23:00:00 +0100 2810057 http://www.medworm.com/index.php?rid=2804564&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19757093%26dopt%3DAbstract 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 functional inactivation induced by SB203580. Our findings suggest the existence of so far unexplored mechanisms of gene regulation in our model system and validate that MDA... Biometals journals http://www.medworm.com/rss/comments.php?id=2804564 Mon, 14 Sep 2009 23:00:00 +0100 2804564 http://www.medworm.com/index.php?rid=2734877&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19701722%26dopt%3DAbstract Authors: Rajasekaran MB, Nilapwar S, Andrews SC, Watson KA 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) like, suggesting a previously unrecognised similarity between EfeO and Fet3p. Our structural modelling of the E. ... Biometals journals http://www.medworm.com/rss/comments.php?id=2734877 Sat, 22 Aug 2009 23:00:00 +0100 2734877 http://www.medworm.com/index.php?rid=2723499&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19697139%26dopt%3DAbstract 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) Biometals journals http://www.medworm.com/rss/comments.php?id=2723499 Thu, 20 Aug 2009 23:00:00 +0100 2723499 http://www.medworm.com/index.php?rid=2723500&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19693677%26dopt%3DAbstract 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 oxidative stress was observed in the liver and brain of CrPic-supplemented normal rats confirmed by the dose-dependent reductions in the levels of hepatic and cerebral fre... Biometals journals http://www.medworm.com/rss/comments.php?id=2723500 Wed, 19 Aug 2009 23:00:00 +0100 2723500 http://www.medworm.com/index.php?rid=2702899&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19680603%26dopt%3DAbstract 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 may be interesting to increase metal toxicity and/or open new paths for metallodrug chemotherapy against leishmaniasis. PMID: 19680603 [PubMed - as supplied by publishe... Biometals journals http://www.medworm.com/rss/comments.php?id=2702899 Wed, 12 Aug 2009 23:00:00 +0100 2702899 http://www.medworm.com/index.php?rid=2696502&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19669622%26dopt%3DAbstract Authors: Validandi V, Rupula K, Beedu SR, Deshpande V 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 reactivity was observed with the anti-fish liver ferritin. Transmission electron microscopy revealed an apparent particl... Biometals journals http://www.medworm.com/rss/comments.php?id=2696502 Sat, 08 Aug 2009 23:00:00 +0100 2696502 http://www.medworm.com/index.php?rid=2668234&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19649569%26dopt%3DAbstract Authors: Pynyaha YV, Boretsky YR, Fedorovych DV, Fayura LR, Levkiv AI, Ubiyvovk VM, Protchenko OV, Philpott CC, Sibirny AA 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 in sulfate assimilation. Cellular iron content i... Biometals journals http://www.medworm.com/rss/comments.php?id=2668234 Fri, 31 Jul 2009 23:00:00 +0100 2668234 http://www.medworm.com/index.php?rid=2639944&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19629715%26dopt%3DAbstract 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) Biometals journals http://www.medworm.com/rss/comments.php?id=2639944 Wed, 22 Jul 2009 23:00:00 +0100 2639944 http://www.medworm.com/index.php?rid=2614577&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19609684%26dopt%3DAbstract Authors: Yamaki K, Yoshino S 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 beta-hexosaminidase was obviously attenuated by ultrafine ZnO particles and ZnSO(4), whereas it was very weakly inhibited by fine ZnO partic... Biometals journals http://www.medworm.com/rss/comments.php?id=2614577 Thu, 16 Jul 2009 23:00:00 +0100 2614577 http://www.medworm.com/index.php?rid=2602402&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19597710%26dopt%3DAbstract Authors: Bertrand S, Larcher G, Landreau A, Richomme P, Duval O, Bouchara JP 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, and separated by reverse phase high performance liquid chromatography. Two siderophores, dime... Biometals journals http://www.medworm.com/rss/comments.php?id=2602402 Sat, 11 Jul 2009 23:00:00 +0100 2602402 http://www.medworm.com/index.php?rid=2562544&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19565338%26dopt%3DAbstract Authors: Rabbani S, Corona F, Ernst B 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 shows substrate specificity for Type I disaccharide (1) with a K (M) of 114 muM. In addition, the H. pylori alpha-1,4 fucosyltransferase... Biometals journals http://www.medworm.com/rss/comments.php?id=2562544 Mon, 29 Jun 2009 23:00:00 +0100 2562544 http://www.medworm.com/index.php?rid=2545336&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19513589%26dopt%3DAbstract Authors: Rock C, Moos PJ 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. In addition, factors that influence inflammatory processes like cytokines and their regulators have been implicated in selenoprotein P transcri... Biometals journals http://www.medworm.com/rss/comments.php?id=2545336 Tue, 09 Jun 2009 23:00:00 +0100 2545336 http://www.medworm.com/index.php?rid=2545341&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19499192%26dopt%3DAbstract 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, brain, liver and kidney of suckling rats. Selenium levels in plasma, brain, and kidney also decreased. These findings suggest that higher Se intake could efficiently redu... Biometals journals http://www.medworm.com/rss/comments.php?id=2545341 Thu, 04 Jun 2009 23:00:00 +0100 2545341 http://www.medworm.com/index.php?rid=2545344&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19484408%26dopt%3DAbstract Authors: Pierron F, Baudrimont M, Dufour S, Elie P, Bossy A, Lucia M, Massabuau JC 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) and oxidative stress (catalase, CAT) were investigated. Our results show that ovarian ... Biometals journals http://www.medworm.com/rss/comments.php?id=2545344 Sat, 30 May 2009 23:00:00 +0100 2545344 http://www.medworm.com/index.php?rid=2545347&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19479326%26dopt%3DAbstract Authors: Maurice PA, Haack EA, Mishra B 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 absorption spectroscopy may be applied to such studies; review effects of siderophores on metal sorption to clays; and highlight s... Biometals journals http://www.medworm.com/rss/comments.php?id=2545347 Thu, 28 May 2009 23:00:00 +0100 2545347 http://www.medworm.com/index.php?rid=2545353&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19459055%26dopt%3DAbstract Authors: Wang W, Chi Z, Liu G, Buzdar MA, Chi Z, Gu Q 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 expression of the hydroxylase gene in the yeast cells grown in the medium plus ornithine was enhanced. PMID: 194590... Biometals journals http://www.medworm.com/rss/comments.php?id=2545353 Wed, 20 May 2009 23:00:00 +0100 2545353 http://www.medworm.com/index.php?rid=2545350&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19459056%26dopt%3DAbstract Authors: Matthijs S, Laus G, Meyer JM, Abbaspour-Tehrani K, Schäfer M, Budzikiewicz H, Cornelis P 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 produces an already characterised pyoverdine, but different from P... Biometals journals http://www.medworm.com/rss/comments.php?id=2545350 Wed, 20 May 2009 23:00:00 +0100 2545350 http://www.medworm.com/index.php?rid=2545355&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19421874%26dopt%3DAbstract Authors: Ze Y, Yin S, Ji Z, Luo L, Liu C, Hong F 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 chloroplast was reduced in spinach grown in magnesium-deficiency media, it caused a significant reduction of spinach plan... Biometals journals http://www.medworm.com/rss/comments.php?id=2545355 Wed, 06 May 2009 23:00:00 +0100 2545355 http://www.medworm.com/index.php?rid=2545364&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19404747%26dopt%3DAbstract Authors: Wang Q, Yang ZY, Qi GF, Qin DD 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) Biometals journals http://www.medworm.com/rss/comments.php?id=2545364 Wed, 29 Apr 2009 23:00:00 +0100 2545364 http://www.medworm.com/index.php?rid=2545361&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19404748%26dopt%3DAbstract 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) Biometals journals http://www.medworm.com/rss/comments.php?id=2545361 Wed, 29 Apr 2009 23:00:00 +0100 2545361 http://www.medworm.com/index.php?rid=2545359&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19404749%26dopt%3DAbstract Authors: Li M, Ding W, Smee JJ, Baruah B, Willsky GR, Crans DC 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 blood glucose-lowering effects when administered to diabetic rats for 20 days. However, the levels of fast... Biometals journals http://www.medworm.com/rss/comments.php?id=2545359 Tue, 28 Apr 2009 23:00:00 +0100 2545359 http://www.medworm.com/index.php?rid=2545367&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19399629%26dopt%3DAbstract Authors: Dong S, Zhao Y, Liu H, Yang X, Wang K 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, reduction of DeltaPsi(m) and cytochrome c release. Inhibition of PTP with 10 muM CsA attenuated the effects of La(3+). Howe... Biometals journals http://www.medworm.com/rss/comments.php?id=2545367 Mon, 27 Apr 2009 23:00:00 +0100 2545367 http://www.medworm.com/index.php?rid=2323356&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19357969%26dopt%3DAbstract Authors: González-López MA, Olivares-Trejo JJ 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 growth in media without free iron but supplemented with Hb. All these results support the idea that frpB2 is a gene of ... Biometals journals http://www.medworm.com/rss/comments.php?id=2323356 Thu, 09 Apr 2009 04:00:00 +0100 2323356 http://www.medworm.com/index.php?rid=2323354&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19357970%26dopt%3DAbstract Authors: Homann VV, Edwards KJ, Webb EA, Butler A 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 the fatty acid chain length affects the relative amphiphilicity within a suite of siderophores. Catecholate sulfonation i... Biometals journals http://www.medworm.com/rss/comments.php?id=2323354 Thu, 09 Apr 2009 04:00:00 +0100 2323354 http://www.medworm.com/index.php?rid=2323352&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19357971%26dopt%3DAbstract Authors: Harrington JM, Crumbliss AL 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) Biometals journals http://www.medworm.com/rss/comments.php?id=2323352 Thu, 09 Apr 2009 04:00:00 +0100 2323352 http://www.medworm.com/index.php?rid=2323358&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19353276%26dopt%3DAbstract Authors: Marchlewicz M, Baranowska-Bosiacka I, Kolasa A, Kondarewicz A, Chlubek D, Wiszniewska B 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 high performance liquid chromatography (HPLC) and detected even at low lead... Biometals journals http://www.medworm.com/rss/comments.php?id=2323358 Wed, 08 Apr 2009 04:00:00 +0100 2323358 http://www.medworm.com/index.php?rid=2323366&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19350395%26dopt%3DAbstract Authors: Holinsworth B, Martin JD 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 natural products secreted by a marine Penicillium bilaii revealed that this strain produced the rare catecholate siderophore pistillarin when... Biometals journals http://www.medworm.com/rss/comments.php?id=2323366 Tue, 07 Apr 2009 04:00:00 +0100 2323366 http://www.medworm.com/index.php?rid=2323363&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19350396%26dopt%3DAbstract Authors: Frederick RE, Mayfield JA, Dubois JL 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) Biometals journals http://www.medworm.com/rss/comments.php?id=2323363 Tue, 07 Apr 2009 04:00:00 +0100 2323363 http://www.medworm.com/index.php?rid=2323360&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19350397%26dopt%3DAbstract Authors: Gademann K, Kobylinska J, Wach JY, Woods TM 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 dopamine derivatives featuring a quaternary ammonium group were found to be equally efficient in generating antifouling su... Biometals journals http://www.medworm.com/rss/comments.php?id=2323360 Tue, 07 Apr 2009 04:00:00 +0100 2323360 http://www.medworm.com/index.php?rid=2323369&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19343508%26dopt%3DAbstract Authors: Hopkinson BM, Morel FM 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 accessing iron from strong chelates since the majority of dissolved iron in seawater is complexed by organic ligands, including siderophores. Ra... Biometals journals http://www.medworm.com/rss/comments.php?id=2323369 Fri, 03 Apr 2009 04:00:00 +0100 2323369 http://www.medworm.com/index.php?rid=2323372&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19340589%26dopt%3DAbstract Authors: Lavilla I, Costas M, Miguel PS, Millos J, Bendicho C 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 elevated concentrations of essential elements as compared to non-tumours. On the contrary, elements considered ... Biometals journals http://www.medworm.com/rss/comments.php?id=2323372 Thu, 02 Apr 2009 04:00:00 +0100 2323372 http://www.medworm.com/index.php?rid=2323383&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19337842%26dopt%3DAbstract Authors: Lucia M, Andre JM, Gonzalez P, Baudrimont M, Gontier K, Maury-Brachet R, Davail S 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 stable level at 20 days of contamination even if the concentrations in muscle stil... Biometals journals http://www.medworm.com/rss/comments.php?id=2323383 Wed, 01 Apr 2009 04:00:00 +0100 2323383 http://www.medworm.com/index.php?rid=2323411&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19333556%26dopt%3DAbstract Authors: Campos JA, Tejera NA, Sánchez CJ 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 capability to accumulate these elements. The maximum absorption of Nd and Pb was found in the ectomycorrhizal Cantharellus ci... Biometals journals http://www.medworm.com/rss/comments.php?id=2323411 Tue, 31 Mar 2009 04:00:00 +0100 2323411 http://www.medworm.com/index.php?rid=2323431&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19330492%26dopt%3DAbstract 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 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 oxid... Biometals journals http://www.medworm.com/rss/comments.php?id=2323431 Sun, 29 Mar 2009 04:00:00 +0100 2323431 http://www.medworm.com/index.php?rid=2323433&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19330300%26dopt%3DAbstract 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 suggesting that regulation is independent of liver iron levels. Together, these results suggest that older mice have a distinct response to alterations in iron metabolism ... Biometals journals http://www.medworm.com/rss/comments.php?id=2323433 Sat, 28 Mar 2009 04:00:00 +0100 2323433 http://www.medworm.com/index.php?rid=2295274&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19326051%26dopt%3DAbstract Authors: Sakamoto H, Kuboi T, Nagakura T, Hayashi S, Hoshi F, Mutoh K, Watanabe K, Orino K 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) to ferritin by immunoblot analysis with antibodies specific for feline IgG, I... Biometals journals http://www.medworm.com/rss/comments.php?id=2295274 Fri, 27 Mar 2009 04:00:00 +0100 2295274 http://www.medworm.com/index.php?rid=2295298&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19306086%26dopt%3DAbstract We describe zinc uptake and release by respiratory epithelial cells and test the postulate that Zn(2+) transport interacts with iron homeostasis in these same cells. Zn(2+) uptake after 4 and 8 h of exposure to zinc sulfate was concentration- and time-dependent. A majority of Zn(2+) release occurred in the 4 h immediately following cell exposure to ZnSO(4). Regarding metal importers, mRNA for Zip1 and Zip2 showed no change after respiratory epithelial cell exposure to zinc while mRNA for divalent metal transporter (DMT)1 increased. Western blot assay for DMT1 protein supported an elevated expression of this transport protein following zinc exposure. RT-PCR confirmed mRNA for the metal exporters ZnT1 and ZnT4 with the former increasing after ZnSO(4). Cell concentrations of ferritin increase... Biometals journals http://www.medworm.com/rss/comments.php?id=2295298 Sun, 22 Mar 2009 04:00:00 +0100 2295298 http://www.medworm.com/index.php?rid=2295405&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19306065%26dopt%3DAbstract Authors: Ding ZC, Teng XC, Zheng Q, Ni FY, Cai B, Wang Y, Zhou GM, Sun HZ, Tan XS, Huang ZX Metallothinein-3 (MT3), also named neuronal growth inhibitory factor (GIF), is attractive by its distinct neuronal growth inhibitory activity, which is not shared by other MT isoforms. The polypeptide chain of GIF is folded into two individual domains, which are connected by a highly conserved linker, KKS. In order to figure out the significance of the conserved segment, we constructed several mutants of human GIF (hGIF), including the K31/32A mutant, the K31/32E mutant and the KKS-SP mutant by site-directed mutagenesis. pH titration and DTNB reaction exhibited that all the three mutations made the beta-domain lower in stability and looser. More significantly, change of KKS to SP also altered th... Biometals journals http://www.medworm.com/rss/comments.php?id=2295405 Sat, 21 Mar 2009 04:00:00 +0100 2295405 http://www.medworm.com/index.php?rid=2283097&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19294337%26dopt%3DAbstract Authors: Cardin GB, Mantha M, Jumarie C Cadmium (Cd) is a highly toxic metal that enters the food chain. Following oral ingestion, the intestinal epithelium is the first biological barrier crossed by Cd and is also an important target tissue. In the present study, the human intestinal Caco-2 cell line was used to evaluate the impact of a low level of exposure on both undifferentiated and differentiated intestinal cells. As revealed by the LC(50) values estimated with the 3-[4,5-dimethyl-2-thiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, mature Caco-2 cells were more resistant to Cd. However, following a 24-h exposure to non-cytotoxic levels of Cd (10 muM) or zinc (Zn, 100 muM), threefold increases were obtained in the LC(50) values of 7-day-old cells, whereas increased resist... Biometals journals http://www.medworm.com/rss/comments.php?id=2283097 Wed, 18 Mar 2009 04:00:00 +0100 2283097 http://www.medworm.com/index.php?rid=2273015&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19288211%26dopt%3DAbstract Authors: Silva AM, Kong X, Hider RC Citric acid is an important metal chelator of biological relevance. Citric acid helps solubilizing metals, increasing their bioavailability for plants and microbes and it is also thought to be a constituent of both the extracellular and cytoplasmic low molecular iron pools occurring in plants and vertebrates. Metal coordination by citric acid involves coordination both by the carboxylate and hydroxyl groups, of particular interest is its alpha-hydroxycarboxylate function. This structural feature is highly conserved in siderophores produced by evolutionarily distant species and seems to confer specificity toward Fe(III) binding. In order to understand the mechanism of metal coordination by alpha-hydroxycarboxylates and correctly evaluate the respectiv... Biometals journals http://www.medworm.com/rss/comments.php?id=2273015 Sat, 14 Mar 2009 04:00:00 +0100 2273015 http://www.medworm.com/index.php?rid=2257364&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19277875%26dopt%3DAbstract Authors: Kraepiel AM, Bellenger JP, Wichard T, Morel FM Free-living nitrogen-fixing bacteria in soils need to tightly regulate their uptake of metals in order to acquire essential metals (such as the nitrogenase metal cofactors Fe, Mo and V) while excluding toxic ones (such as W). They need to do this in a soil environment where metal speciation, and thus metal bioavailability, is dependent on a variety of factors such as organic matter content, mineralogical composition, and pH. Azotobacter vinelandii, a ubiquitous gram-negative soil diazotroph, excretes in its external medium catechol compounds, previously identified as siderophores, that bind a variety of metals in addition to iron. At low concentrations, complexes of essential metals (Fe, Mo, V) with siderophores are taken up by th... Biometals journals http://www.medworm.com/rss/comments.php?id=2257364 Tue, 10 Mar 2009 04:00:00 +0100 2257364 http://www.medworm.com/index.php?rid=2242561&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19262998%26dopt%3DAbstract Authors: Sugiura T, Noguchi Y Protein phosphatase 2C (PP2C) family is characterized by requirement of metal cation for phosphatase activity. We previously established that PPM1H is a cancer-associated member of the PP2C family. Here we further characterized the phosphatase activity of PPM1H, focusing on its dependence on metal cation. PPM1H possesses the potential to dephosphorylate p-nitrophenyl phosphate (pNPP), casein and phosphopeptides. Interestingly, PPM1H shows the metal preference that is varied depending on the substrate (substrate-dependent metal preference); PPM1H prefers Mn(2+) when pNPP or phosphopeptides is used as a substrate. Meanwhile, a preference for Mg(2+) is displayed by PPM1H with casein as a substrate. When both cations are added to the reaction, the degree of th... Biometals journals http://www.medworm.com/rss/comments.php?id=2242561 Thu, 05 Mar 2009 05:00:00 +0100 2242561 http://www.medworm.com/index.php?rid=2218231&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19241122%26dopt%3DAbstract Authors: Liu YC, Yang ZY X-ray crystal and other structural analyses indicate that Yb(III) and all four newly synthesized ligands can form a binuclear Yb(III) complex with a 1:1 metal to ligand stoichiometry by octacoordination at the Yb(III) center. Investigations of DNA binding properties show that all the ligands and Yb(III) complexes can bind to Calf thymus DNA through intercalations with the binding constants at the order of magnitude 10(5)-10(7) M(-1), but Yb(III) complexes present stronger affinities to DNA than ligands. All the ligands and Yb(III) complexes may be used as potential anticancer drugs. Investigations of antioxidation properties show that all the ligands and Yb(III) complexes have strong scavenging effects for hydroxyl radicals and superoxide radicals but Yb(III) c... Biometals journals http://www.medworm.com/rss/comments.php?id=2218231 Wed, 25 Feb 2009 05:00:00 +0100 2218231 http://www.medworm.com/index.php?rid=2218232&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19238560%26dopt%3DAbstract Authors: Duckworth OW, Bargar JR, Sposito G Siderophores, biogenic chelating agents that facilitate Fe(III) uptake through the formation of strong complexes, also form strong complexes with Mn(III) and exhibit high reactivity with Mn (hydr)oxides, suggesting a pathway by which Mn may disrupt Fe uptake. In this review, we evaluate the major biogeochemical mechanisms by which Fe and Mn may interact through reactions with microbial siderophores: competition for a limited pool of siderophores, sorption of siderophores and metal-siderophore complexes to mineral surfaces, and competitive metal-siderophore complex formation through parallel mineral dissolution pathways. This rich interweaving of chemical processes gives rise to an intricate tapestry of interactions, particularly in respect to... Biometals journals http://www.medworm.com/rss/comments.php?id=2218232 Tue, 24 Feb 2009 05:00:00 +0100 2218232 http://www.medworm.com/index.php?rid=2195988&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19221879%26dopt%3DAbstract Authors: Wencewicz TA, Möllmann U, Long TE, Miller MJ The recent rise in drug resistance found amongst community acquired infections has sparked renewed interest in developing antimicrobial agents that target resistant organisms and limit the natural selection of immune variants. Recent discoveries have shown that iron uptake systems in bacteria and fungi are suitable targets for developing such therapeutic agents. The use of siderophore-drug conjugates as "Trojan Horse" drug delivery agents has attracted particular interest in this area. This review will discuss efforts in our research group to study the salmycin class of "Trojan Horse" antibiotics. Inspired by the natural design of the salmycins, a series of desferridanoxamine-antibiotic conjugates were synthesized and tested in... Biometals journals http://www.medworm.com/rss/comments.php?id=2195988 Tue, 17 Feb 2009 05:00:00 +0100 2195988 http://www.medworm.com/index.php?rid=2188626&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19214756%26dopt%3DAbstract Authors: Müller SI, Valdebenito M, Hantke K Salmochelin is a C-glucosylated enterobactin produced by Salmonella species, uropathogenic and avian pathogenic Escherichia coli strains, and certain Klebsiella strains. It was the first glucosylated siderophore described. The glucosylation has been interpreted as a bacterial evasion mechanism against the mammalian catecholate siderophore-binding protein siderocalin (NGAL-lipocalin). The synthesis, excretion, and uptake of salmochelin requires five genes, iroBCDEN, and also the enterobactin biosynthesis and utilization system. Some salmochelin-producing strains also secrete microcins, which possess a C-terminal, linear glucosyl-enterobactin moiety. These microcins recognize the catecholate siderophore receptors IroN, Cir, Fiu, and FepA, ... Biometals journals http://www.medworm.com/rss/comments.php?id=2188626 Fri, 13 Feb 2009 05:00:00 +0100 2188626 http://www.medworm.com/index.php?rid=2188627&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19214755%26dopt%3DAbstract Authors: Möllmann U, Heinisch L, Bauernfeind A, Köhler T, Ankel-Fuchs D The outer membrane permeability barrier is an important resistance factor of bacterial pathogens. In combination with drug inactivating enzymes, target alteration and efflux, it can increase resistance dramatically. A strategy to overcome this membrane-mediated resistance is the misuse of bacterial transport systems. Most promising are those for iron transport. They are vital for virulence and survival of bacteria in the infected host, where iron depletion is a defense mechanism against invading pathogens. We synthesized biomimetic siderophores as shuttle vectors for active transport of antibiotics through the bacterial membrane. Structure activity relationship studies resulted in siderophore aminopenicil... Biometals journals http://www.medworm.com/rss/comments.php?id=2188627 Thu, 12 Feb 2009 05:00:00 +0100 2188627 http://www.medworm.com/index.php?rid=2188625&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19214757%26dopt%3DAbstract Authors: Prasad KS, Subramanian V, Paul J The chemolithoautotroph, Arthrobacter sp.15b oxidizes arsenite to arsenate using a membrane bound arsenite oxidase. The enzyme arsenite oxidase is purified to its homogeneity and identified using MALDI-TOF MS analysis. Upon further characterization, it was observed that the enzyme is a heterodimer showing native molecular mass as ~100 kDa and appeared as two subunits of ~85 kDa LSU and 14 kDa SSU on SDS-PAGE. The V (max) and K (m) values of the enzyme was found to be 2.45 muM (AsIII)/min/mg) and 26 muM, respectively. The purified enzyme could withstand wide range of pH and temperature changes. The enzyme, however, gets deactivated in the presence of 1 mM of DEPC suggesting the involvement of histidine at the binding site of the enzyme. The pept... Biometals journals http://www.medworm.com/rss/comments.php?id=2188625 Thu, 12 Feb 2009 05:00:00 +0100 2188625 http://www.medworm.com/index.php?rid=2184557&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205899%26dopt%3DAbstract Authors: Ferrari E, Arezzini B, Ferrali M, Lazzari S, Pignedoli F, Spagnolo F, Saladini M The Fe(3+) chelating ability of some curcumin glucosyl derivatives (Glc-H; Glc-OH; Glc-OCH(3)) is tested by means of UV and NMR study. The pK (a) values of the ligands and the overall stability constants of Fe(3+) and Ga(3+) complexes are evaluated from UV spectra. The only metal binding site of the ligand is the beta-diketo moiety in the keto-enolic form; the glucosyl moiety does not interact with metal ion but it contributes to the stability of metal/ligand 1:2 complexes by means of hydrophilic interactions. These glucosyl derivatives are able to bind Fe(3+) in a wide pH rage, forming complex species thermodynamically more stable than those of other ligands commonly used in the treatment of iron... Biometals journals http://www.medworm.com/rss/comments.php?id=2184557 Wed, 11 Feb 2009 05:00:00 +0100 2184557 http://www.medworm.com/index.php?rid=2184556&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205900%26dopt%3DAbstract Authors: Drum DA Cadmium, arsenic, lead, and mercury have been linked to autism, attention deficit disorder, mental retardation and death of children. Mercury in thimerosal found in many vaccines and flu shots contributes significantly to these problems. Decomposition of the thimerosal can produce more toxic compounds, either methylethylmercury or diethylmercury, in the body. These compounds have a toxicity level similar to dimethylmercury. Within the human body, a mitochondrial disorder may release the more toxic form of mercury internally. Young children and pregnant women must minimize internal exposure to the vaccines and flu shots containing mercury. PMID: 19205900 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=2184556 Wed, 11 Feb 2009 05:00:00 +0100 2184556 http://www.medworm.com/index.php?rid=2184555&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205901%26dopt%3DAbstract Authors: Marques J, Braga TM, Almeida Paz FA, Santos TM, de Fátima Silva Lopes M, Braga SS The complex [Ru([9]aneS(3))phenCl]Cl (phen = 1,10-phenanthroline) and its synthetic precursor [Ru([9]aneS(3))dmsoCl(2)] were immobilized in permethylated beta-cyclodextrin (TRIMEB). A new crystalline structure of the precursor, obtained from a batch ethanol solution at low temperature (4 degrees C), is fully described from single-crystal X-ray diffraction data. [Ru([9]aneS(3))phenCl]Cl was also encapsulated in native beta-cyclodextrin for comparison with the TRIMEB compound. All three compounds were obtained with a 1:1 host:guest stoichiometry and were studied by powder X-ray diffraction (including synchrotron radiation data), thermogravimetric analysis (TGA), (13)C{(1)H} CP/MAS NMR and FTIR... Biometals journals http://www.medworm.com/rss/comments.php?id=2184555 Wed, 11 Feb 2009 05:00:00 +0100 2184555 http://www.medworm.com/index.php?rid=2184554&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19205902%26dopt%3DAbstract Authors: Afton SE, Caruso JA, Britigan BE, Qin Z Copper egress is an essential regulator of the kinetics of cellular copper and is primarily regulated by ATP7A, a copper-transporting P-type ATPase. However, little is known under which physiological condition copper egress is induced and its molecular consequence. In current manuscript, using THP-1 cells, a human monocytic cell line, we found that ATP7A expression was increased in cells exposed to phorbol-12-myristate-13-acetate (PMA), a potent inducer of neovascularization and cancer. Inductively coupled plasma mass spectrometry revealed that PMA also induced copper egress. Inhibition of ATP7A expression using small interfering RNA abrogated PMA induced copper egress. PMA treatment in THP-1 cells resulted in increased expression of mat... Biometals journals http://www.medworm.com/rss/comments.php?id=2184554 Tue, 10 Feb 2009 05:00:00 +0100 2184554 http://www.medworm.com/index.php?rid=2174767&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19199091%26dopt%3DAbstract This study reports on the accumulation of iron within the tube wall of the deep sea vent macro invertebrate Vestimentiferan Ridgeia piscesae collected from Juan de Fuca ridge. Combining an array of approaches including environmental scanning electron microscope (ESEM), electron probe micro-analysis (EPMA), X-ray microanalysis (EDS) and transmission electron microscope (TEM), we provide evidences for the influence of prokaryotic organisms on the accumulation of metals on and within the tube wall. Two types of iron-rich minerals such as iron oxides and framboidal pyrites are identified within or on the tube wall. Our results reveal the presence of prokaryotic organism is apparently responsible for the early accumulation of iron-rich minerals in the tube wall. The implications of the biominer... Biometals journals http://www.medworm.com/rss/comments.php?id=2174767 Sun, 08 Feb 2009 05:00:00 +0100 2174767 http://www.medworm.com/index.php?rid=2161219&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19190985%26dopt%3DAbstract Authors: Deb S, Johnson EE, Robalinho-Teixeira RL, Wessling-Resnick M Reactive oxygen species (ROS) display cytotoxicity that can be exacerbated by iron. Paradoxically, HeLa cells treated with the ROS-generators menadione and 2,3-dimethoxy-1,4-naphthoquinone display increased free labile iron. HeLa cells exposed to ROS undergo apoptosis but iron chelation limits the extent of cell death suggesting the rise in intracellular iron plays a signaling role in this pathway. This idea is supported by the fact that iron chelation also alters the pattern of ROS-induced phosphorylation of stress-activated protein kinases SAPK/JNK and p38 MAPK. Thus, ROS-induced increases in cellular free iron contribute to signaling events triggered during oxidative stress response. PMID: 19190985 [PubMed - a... Biometals journals http://www.medworm.com/rss/comments.php?id=2161219 Wed, 04 Feb 2009 05:00:00 +0100 2161219 http://www.medworm.com/index.php?rid=2157606&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19189056%26dopt%3DAbstract Authors: Sokolov AV, Ageeva KV, Pulina MO, Zakharova ET, Vasilyev VB In our previous report we first described a complex between lactoferrin (Lf) and ceruloplasmin (Cp) with K (d) ~ 1.8 muM. The presence of this complex in colostrum that never contains more than 0.3 muM Cp questions the reliability of K (d) value. We carefully studied Lf binding to Cp and investigated the enzymatic activity of the latter in the presence of Lf, which allowed obtaining a new value for K (d) of Cp-Lf complex. Lf interacting with Cp changes its oxidizing activity with various substrates, such as Fe(2+), o-dianisidine (o-DA), p-phenylenediamine (p-PD) and dihydroxyphenylalanine (DOPA). The presence of at least two binding sites for Lf in Cp molecule is deduced from comparison of substrates' oxidation kineti... Biometals journals http://www.medworm.com/rss/comments.php?id=2157606 Tue, 03 Feb 2009 05:00:00 +0100 2157606 http://www.medworm.com/index.php?rid=2153511&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19184458%26dopt%3DAbstract Authors: Clifton MC, Corrent C, Strong RK Recent studies have revealed that the mammalian immune system directly interferes with siderophore-mediated iron acquisition through siderophore-binding proteins and that the association of certain siderophores, or siderophore modifications, with virulence is a direct response of pathogens to evade these defenses. PMID: 19184458 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=2153511 Fri, 30 Jan 2009 05:00:00 +0100 2153511 http://www.medworm.com/index.php?rid=2153512&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19184457%26dopt%3DAbstract Authors: Zhang Y, Fu LJ, Li JX, Yang XG, Yang XD, Wang K The effect of gadolinium chloride (Gd) on the proliferation of HeLa cells was investigated at lower concentration. The results obtained by MTT and cell cycle analysis showed that Gd promoted proliferation by inducing S phase entry in HeLa cells at the concentration less than 100 muM. It was further evidenced by both an increase in the levels of phosphorylation of retinoblastoma protein (pRb) and a remarkable increase in cyclin E expression. Moreover, the survival of cells, exposed to Gd up to 3-5 days, was increased compared with control. The attenuation of the serum deprivation-induced cell loss by Gd was associated with the sustained activation of FAK (PY(397)) and the delayed activation of JNKs pathway. Besides, it appeared th... Biometals journals http://www.medworm.com/rss/comments.php?id=2153512 Thu, 29 Jan 2009 05:00:00 +0100 2153512 http://www.medworm.com/index.php?rid=2153510&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19184459%26dopt%3DAbstract Authors: Miller MJ, Li H, Foss CA Antisense oligonucleotides with iron binding hydroxamate linkages are designed to act as sequence-selective cleaving agents of complementary nucleic acids through Fenton chemistry. Oligothymidylate analogs with hydroxamate linkages were efficiently synthesized from coupling of nucleoside intermediates, activated as p-nitrophenyl carbonates, with hydroxylamine derivatized nucleosides. Iron binding studies showed that hydroxamate linked oligonucleotides are effective iron chelators when there are three nonadjacent internucleosidic hydroxamate linkages available in the same oligonucleotide molecule. However, analysis of the CD spectra of an oligothymidylate 16mer, which contained complete substitution of all phosphates with hydroxamates, indicated that th... Biometals journals http://www.medworm.com/rss/comments.php?id=2153510 Wed, 28 Jan 2009 05:00:00 +0100 2153510 http://www.medworm.com/index.php?rid=2122755&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19153809%26dopt%3DAbstract Authors: Schalk IJ, Lamont IL, Cobessi D FpvA is the primary outer membrane transporter required for iron acquisition via the siderophore pyoverdine (Pvd) in Pseudomonas aeruginosa. FpvA, like other ferrisiderophore transporters, consists of a membrane-spanning beta-barrel occluded by a plug domain. The beta-strands of the barrel are connected by large extracellular loops and periplasmic turns. Like some other TonB-dependent transporters, FpvA has a periplasmic domain involved in a signalling cascade that regulates expression of genes required for ferrisiderophore transport. Here, the structures of FpvA in different loading states are analysed in light of mutagenesis data. This analysis highlights the roles of different protein domains in Pvd-Fe uptake and the signalling cascade and re... Biometals journals http://www.medworm.com/rss/comments.php?id=2122755 Tue, 20 Jan 2009 05:00:00 +0100 2122755 http://www.medworm.com/index.php?rid=2117143&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19152114%26dopt%3DAbstract Authors: Posmyk MM, Janas KM, Kontek R Red cabbage is a source of health beneficial substances with antioxidant and antigenotoxic properties. HPLC analysis specifying the content of the investigated extract indicated that mainly anthocyanins (ATH) were responsible for its abilities. Cytological research was conducted with two experimental models: plant tissues-meristematic cells of Vicia faba, and animal tissue elements-human lymphocytes. Positive influence of ATH extract on mitotic activity of Vicia cells exposed to Cu(2+) stress, and inhibitory effect of ATH on cytotoxic actions of Cu(2+) on lymphocytes were demonstrated. In all experimental series with ATH application in combinations with Cu(2+), mitotic index (MI) were higher than those obtained for only Cu(2+) stressed tissues. Pr... Biometals journals http://www.medworm.com/rss/comments.php?id=2117143 Mon, 19 Jan 2009 05:00:00 +0100 2117143 http://www.medworm.com/index.php?rid=2102195&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19140013%26dopt%3DAbstract Authors: Pushie MJ, Rauk A, Jirik FR, Vogel HJ The native prion protein (PrP) has a two domain structure, with a globular folded alpha-helical C-terminal domain and a flexible extended N-terminal region. The latter can selectively bind Cu(2+) via four His residues in the octarepeat (OR) region, as well as two sites (His96 and His111) outside this region. In the disease state, the folded C-terminal domain of PrP undergoes a conformational change, forming amorphous aggregates high in beta-sheet content. Cu(2+) bound to the ORs can be redox active and has been shown to induce cleavage within the OR region, a process requiring conserved Trp residues. Using computational modeling, we have observed that electron transfer from Trp residues to copper can be favorable. These models also reveal ... Biometals journals http://www.medworm.com/rss/comments.php?id=2102195 Tue, 13 Jan 2009 05:00:00 +0100 2102195 http://www.medworm.com/index.php?rid=2102194&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19140014%26dopt%3DAbstract Authors: Justino MC, Baptista JM, Saraiva LM A key element in eukaryotic immune defenses against invading microbes is the production of reactive oxygen and nitrogen species. One of the main targets of these species are the iron-sulfur clusters, which are essential prosthetic groups that confer to proteins the ability to perform crucial roles in biological processes. Microbes have developed sophisticated systems to eliminate nitrosative and oxidative species and promote the repair of the damages inflicted. The Ric (Repair of Iron Centers) proteins constitute a novel family of microbial di-iron proteins with a widespread distribution among microbes, including Gram-positive and Gram-negative bacteria, protozoa and fungi. The Ric proteins are encoded by genes that are up-regulated by nitri... Biometals journals http://www.medworm.com/rss/comments.php?id=2102194 Tue, 13 Jan 2009 05:00:00 +0100 2102194 http://www.medworm.com/index.php?rid=2102193&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19140015%26dopt%3DAbstract Authors: Auld DS The inner shell coordination properties of zinc proteins have led to the identification of four types of zinc binding sites: catalytic, cocatalytic, structural, and protein interface. Outer shell coordination can influence the stability of the zinc site and its function as exemplified herein by the zinc sites in carbonic anhydrase, promatrix metalloproteases and alcohol dehydrogenase. Agents that disrupt these interactions, can lead to increased off rate constants for zinc. D: -penicillamine is the first drug to inhibit a zinc protease by catalyzing the removal of the metal. Since it can accept the released zinc we have referred to it as a catalytic chelator. Agents that catalyze the release of the metal in the presence of a scavenger chelator will also inhibit enzyme ... Biometals journals http://www.medworm.com/rss/comments.php?id=2102193 Tue, 13 Jan 2009 05:00:00 +0100 2102193 http://www.medworm.com/index.php?rid=2090647&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130262%26dopt%3DAbstract Authors: Kuehl CJ, Crosa JH TtpC is a fourth required protein in the TonB2 energy transduction system in Vibrio anguillarum. TtpC is necessary for iron transport mediated by the TonB2 system and is highly conserved in all pathogenic vibrio species studied to date as well as several marine organisms. We show here that the TtpC proteins from selected pathogenic vibrio species can function with the TonB2 system of V. anguillarum to allow iron transport mediated by a chimeric TonB2 system where the native ExbB2, ExbD2 and TonB2 function with an episomally expressed TtpC in trans from a different species. The discovery that inter-species complementation occurs can be used to identify the functional regions of the TtpC proteins and will lead to an investigation of the mechanism of interactio... Biometals journals http://www.medworm.com/rss/comments.php?id=2090647 Thu, 08 Jan 2009 05:00:00 +0100 2090647 http://www.medworm.com/index.php?rid=2090646&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130263%26dopt%3DAbstract Authors: Cornelis P, Matthijs S, Van Oeffelen L The Pseudomonas genus belongs to the gamma division of Proteobacteria and many species produce the characteristic yellow-green siderophore pyoverdine, and often a second siderophore, of lower affinity for iron. These bacteria are known for their ability to colonize different ecological niches and for their versatile metabolism. It is therefore not surprising that they are endowed with the capacity to take up exogenous xenosiderophores via different TonB-dependent receptors. Uptake of iron is controlled by the central regulator Fur, and via extracytoplasmic sigma factors or other types of regulators (two-component systems, AraC regulators). In this review the Fur regulon (experimentally proven and/or predicted) of P. aeruginosa will be pre... Biometals journals http://www.medworm.com/rss/comments.php?id=2090646 Thu, 08 Jan 2009 05:00:00 +0100 2090646 http://www.medworm.com/index.php?rid=2090643&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130266%26dopt%3DAbstract Authors: Darshan D, Anderson GJ The amount of iron in the plasma is determined by the regulated release of iron from most body cells, but macrophages, intestinal enterocytes and hepatocytes play a particularly important role in this process. This cellular iron efflux is modulated by the liver-derived peptide hepcidin, and this peptide is now regarded as the central regulator of body iron homeostasis. Hepcidin expression is influenced by systemic stimuli such as iron stores, the rate of erythropoiesis, inflammation, hypoxia and oxidative stress. These stimuli control hepcidin levels by acting through hepatocyte cell surface proteins including HFE, transferrin receptor 2, hemojuvelin, TMPRSS6 and the IL-6R. The surface proteins activate various cell signal transduction pathways, includin... Biometals journals http://www.medworm.com/rss/comments.php?id=2090643 Thu, 08 Jan 2009 05:00:00 +0100 2090643 http://www.medworm.com/index.php?rid=2090654&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130255%26dopt%3DAbstract Authors: Zimbler DL, Penwell WF, Gaddy JA, Menke SM, Tomaras AP, Connerly PL, Actis LA Acinetobacter baumannii is a gram-negative bacterium that causes serious infections in compromised patients. More recently, it has emerged as the causative agent of severe infections in military personnel wounded in Iraq and Afghanistan. This pathogen grows under a wide range of conditions including iron-limiting conditions imposed by natural and synthetic iron chelators. Initial studies using the type strain 19606 showed that the iron proficiency of this pathogen depends on the expression of the acinetobactin-mediated iron acquisition system. More recently, we have observed that hemin but not human hemoglobin serves as an iron source when 19606 isogenic derivatives affected in acinetobactin transpor... Biometals journals http://www.medworm.com/rss/comments.php?id=2090654 Wed, 07 Jan 2009 05:00:00 +0100 2090654 http://www.medworm.com/index.php?rid=2090653&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130256%26dopt%3DAbstract Authors: Lemos ML PMID: 19130256 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=2090653 Wed, 07 Jan 2009 05:00:00 +0100 2090653 http://www.medworm.com/index.php?rid=2090652&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130257%26dopt%3DAbstract Authors: Ralle M, Lutsenko S Metals and other trace elements play an important role in many physiological processes in all biological systems. Characterization of precise metal concentrations, their spatial distribution, and chemical speciation in individual cells and cell compartments will provide much needed information to explore the metallome in health and disease. Synchrotron-based X-ray fluorescent microscopy (SXRF) is the ideal tool to quantitatively measure trace elements with high sensitivity at high resolution. SXRF is based on the intrinsic fluorescent properties of each element and is therefore element specific. Recent advances in synchrotron technology and optimization of sample preparation have made it possible to image metals in mammalian tissue with submicron resolution... Biometals journals http://www.medworm.com/rss/comments.php?id=2090652 Wed, 07 Jan 2009 05:00:00 +0100 2090652 http://www.medworm.com/index.php?rid=2090651&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130258%26dopt%3DAbstract Authors: Braun V, Pramanik A, Gwinner T, Köberle M, Bohn E Sideromycins are antibiotics covalently linked to siderophores. They are actively transported into gram-positive and gram-negative bacteria. Energy-coupled transport across the outer membrane and the cytoplasmic membrane strongly increases their antibiotic efficiency; their minimal inhibitory concentration is at least 100-fold lower than that of antibiotics that enter cells by diffusion. This is particularly relevant for gram-negative bacteria because the outer membrane, which usually forms a permeability barrier, in this case actively contributes to the uptake of sideromycins. Sideromycin-resistant mutants can be used to identify siderophore transport systems since the mutations are usually in transport genes. Two siderom... Biometals journals http://www.medworm.com/rss/comments.php?id=2090651 Wed, 07 Jan 2009 05:00:00 +0100 2090651 http://www.medworm.com/index.php?rid=2090650&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130259%26dopt%3DAbstract Authors: Biswas KC, Woodards NA, Xu H, Barton LL Molybdate is an essential trace element required by biological systems including the anaerobic sulfate-reducing bacteria (SRB); however, detrimental consequences may occur if molybdate is present in high concentrations in the environment. While molybdate is a structural analog of sulfate and inhibits sulfate respiration of SRB, little information is available concerning the effect of molybdate on pure cultures. We followed the growth of Desulfovibrio gigas ATCC 19364, Desulfovibrio vulgaris Hildenborough, Desulfovibrio desulfuricans DSM 642, and D. desulfuricans DSM 27774 in media containing sub-lethal levels of molybdate and observed a red-brown color in the culture fluid. Spectral analysis of the culture fluid revealed absorption peaks... Biometals journals http://www.medworm.com/rss/comments.php?id=2090650 Wed, 07 Jan 2009 05:00:00 +0100 2090650 http://www.medworm.com/index.php?rid=2090649&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130260%26dopt%3DAbstract Authors: Lamont IL, Konings AF, Reid DW The bacterium Pseudomonas aeruginosa is commonly isolated from the general environment and also infects the lungs of patients with cystic fibrosis (CF). Iron in mammals is not freely available to infecting pathogens although significant amounts of extracellular iron are available in the sputum that occurs in the lungs of CF patients. P. aeruginosa has a large number of systems to acquire this essential nutrient and many of these systems have been characterised in the laboratory. However, which iron acquisition systems are active in CF is not well understood. Here we review recent research that sheds light on how P. aeruginosa obtains iron in the lungs of CF patients. PMID: 19130260 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=2090649 Wed, 07 Jan 2009 05:00:00 +0100 2090649 http://www.medworm.com/index.php?rid=2090648&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130261%26dopt%3DAbstract Authors: Páez-Espino D, Tamames J, de Lorenzo V, Cánovas D Microorganisms have evolved dynamic mechanisms for facing the toxicity of arsenic in the environment. In this sense, arsenic speciation and mobility is also affected by the microbial metabolism that participates in the biogeochemical cycle of the element. The ars operon constitutes the most ubiquitous and important scheme of arsenic tolerance in bacteria. This system mediates the extrusion of arsenite out of the cells. There are also other microbial activities that alter the chemical characteristics of arsenic: some strains are able to oxidize arsenite or reduce arsenate as part of their respiratory processes. These type of microorganisms require membrane associated proteins that transfer electrons from or to arsenic ... Biometals journals http://www.medworm.com/rss/comments.php?id=2090648 Wed, 07 Jan 2009 05:00:00 +0100 2090648 http://www.medworm.com/index.php?rid=2090645&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130264%26dopt%3DAbstract Authors: Brickman TJ, Armstrong SK The bacterial respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica employ multiple alternative iron acquisition pathways to adapt to changes in the mammalian host environment during infection. The alcaligin, enterobactin, and heme utilization pathways are differentially expressed in response to the cognate iron source availability by a mechanism involving substrate-inducible positive regulators. As inducers, the iron sources function as chemical signals termed ferrimones. Ferrimone-sensing allows the pathogen to adapt and exploit early and late events in the infection process. PMID: 19130264 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=2090645 Wed, 07 Jan 2009 05:00:00 +0100 2090645 http://www.medworm.com/index.php?rid=2090644&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130265%26dopt%3DAbstract Authors: Wyckoff EE, Boulette ML, Payne SM Shigella spp. have transport systems for both ferric and ferrous iron. The iron can be taken up as free iron or complexed to a variety of carriers. All Shigella species have both the Feo and Sit systems for acquisition of ferrous iron, and all have at least one siderophore-mediated system for transport of ferric iron. Several of the transport systems, including Sit, Iuc/IutA (aerobactin synthesis and transport), Fec (ferric di-citrate uptake), and Shu (heme transport) are encoded within pathogenicity islands. The presence and the genomic locations of these islands vary considerably among the Shigella species, and even between isolates of the same species. The expression of the iron transport systems is influenced by the concentration of iron a... Biometals journals http://www.medworm.com/rss/comments.php?id=2090644 Wed, 07 Jan 2009 05:00:00 +0100 2090644 http://www.medworm.com/index.php?rid=2090642&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130267%26dopt%3DAbstract Authors: Maret W Zinc(II) ions are essential for all forms of life. In humans, they have catalytic and structural functions in an estimated 3,000 zinc proteins. In addition, they interact with proteins transiently when they regulate proteins or when proteins regulate cellular zinc re-distribution. As yet, these types of zinc proteins have been explored poorly. Therefore the number of zinc/protein interactions is potentially larger than that given by the above estimate. Confronted with such a wide range of functions, which affect virtually all aspects of cellular physiology, investigators have begun to elucidate the molecular mechanisms of cellular homeostatic control of zinc, especially the functions of transporter, sensor, and trafficking proteins, such as metallothioneins, in providi... Biometals journals http://www.medworm.com/rss/comments.php?id=2090642 Wed, 07 Jan 2009 05:00:00 +0100 2090642 http://www.medworm.com/index.php?rid=2090641&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130268%26dopt%3DAbstract Authors: Miller MJ, Zhu H, Xu Y, Wu C, Walz AJ, Vergne A, Roosenberg JM, Moraski G, Minnick AA, McKee-Dolence J, Hu J, Fennell K, Kurt Dolence E, Dong L, Franzblau S, Malouin F, Möllmann U Pathogenic microbes rapidly develop resistance to antibiotics. To keep ahead in the "microbial war", extensive interdisciplinary research is needed. A primary cause of drug resistance is the overuse of antibiotics that can result in alteration of microbial permeability, alteration of drug target binding sites, induction of enzymes that destroy antibiotics (ie., beta-lactamase) and even induction of efflux mechanisms. A combination of chemical syntheses, microbiological and biochemical studies demonstrate that the known critical dependence of iron assimilation by microbes for growth and virulence... Biometals journals http://www.medworm.com/rss/comments.php?id=2090641 Wed, 07 Jan 2009 05:00:00 +0100 2090641 http://www.medworm.com/index.php?rid=2090640&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19130269%26dopt%3DAbstract Authors: Veldhuis NA, Gaeth AP, Pearson RB, Gabriel K, Camakaris J The copper-translocating Menkes (ATP7A, MNK protein) and Wilson (ATP7B, WND protein) P-type ATPases are pivotal for copper (Cu) homeostasis, functioning in the biosynthetic incorporation of Cu into copper-dependent enzymes of the secretory pathway, Cu detoxification via Cu efflux, and specialized roles such as systemic Cu absorption (MNK) and Cu excretion (WND). Essential to these functions is their Cu and hormone-responsive distribution between the trans-Golgi network (TGN) and exocytic vesicles located at or proximal to the apical (WND) or basolateral (MNK) cell surface. Intriguingly, MNK and WND Cu-ATPases expressed in the same tissues perform distinct yet complementary roles. While intramolecular differences may spe... Biometals journals http://www.medworm.com/rss/comments.php?id=2090640 Wed, 07 Jan 2009 05:00:00 +0100 2090640 http://www.medworm.com/index.php?rid=2054346&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19096759%26dopt%3DAbstract Authors: Chen H, Costa M Nickel compounds are important occupational and environmental pollutants. Chronic exposure to these pollutants has been connected with increased risks of respiratory cancers and cardiovascular diseases. However, it is still not clear what are the specific molecular targets for nickel toxicity and carcinogenicity. Here, we propose that the iron- and 2-oxoglutarate-dependent dioxygenase family enzymes are important intracellular targets that mediate the toxicity and carcinogenicity of nickel. In support of this hypothesis, our data show that three different classes of enzymes in this iron- and 2-oxoglutarate-dependent dioxygenase family, including HIF-prolyl hydroxylase PHD2, histone demethylase JHDM2A/JMJD1A, and DNA repair enzyme ABH3, are all highly sensitive ... Biometals journals http://www.medworm.com/rss/comments.php?id=2054346 Fri, 19 Dec 2008 05:00:00 +0100 2054346 http://www.medworm.com/index.php?rid=2054347&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19093075%26dopt%3DAbstract Authors: Small SK, Puri S, O'Brian MR Perception and response to nutritional iron by bacteria is essential for viability, and for the ability to adapt to the environment. The iron response regulator (Irr) is part of a novel regulatory scheme employed by Rhizobium and other Alpha-Proteobacteria to control iron-dependent gene expression. Bradyrhizobium japonicum senses iron through the status of heme biosynthesis to regulate gene expression, thus it responds to an iron-dependent process rather than to iron directly. Irr mediates this response by interacting directly with ferrochelatase, the enzyme that catalyzes the final step in heme biosynthesis. Irr is expressed under iron limitation to both positively and negatively modulate gene expression, but degrades in response to direct binding... Biometals journals http://www.medworm.com/rss/comments.php?id=2054347 Thu, 18 Dec 2008 05:00:00 +0100 2054347 http://www.medworm.com/index.php?rid=2042085&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19082779%26dopt%3DAbstract Authors: Rowan R, Moran C, McCann M, Kavanagh K Larvae of the insect Galleria mellonella were employed to assess the in vivo antifungal efficacy of ([Ag(2)(mal)(phen)(3)]), AgNO(3) and 1,10-phenanthroline. Larvae pre-inoculated with these compounds were protected from a subsequent lethal infection by the yeast Candida albicans while larvae inoculated 1 and 4 h post-infection showed significantly increased survival (P < 0.01) compared to control larvae. Administration of these compounds resulted in an increase over 48 h in the density of insect haemocytes (immune cells) but there was no widespread activation of genes for antimicrobial peptides. This work demonstrates that G. mellonella larvae may be employed to ascertain the antifungal efficacy of silver(I) compounds and offers a rap... Biometals journals http://www.medworm.com/rss/comments.php?id=2042085 Fri, 12 Dec 2008 05:00:00 +0100 2042085 http://www.medworm.com/index.php?rid=2007648&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19048189%26dopt%3DAbstract Authors: Albelda MT, García-España E, Frías JC The innovations in science and technology have allowed researchers to look inside the human body. In some cases, like MRI, the protons present in the body generate enough signal for an image. However, the employ of certain atoms, metallic or non-metallic, enable detection through different imaging techniques (computed tomography, nuclear imaging, ultrasound or optical imaging), and improve the quality of the images. Here we discuss the different imaging atoms used depending on the imaging technique and the new possible imaging atoms for medical applications. PMID: 19048189 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=2007648 Tue, 02 Dec 2008 05:00:00 +0100 2007648 http://www.medworm.com/index.php?rid=2007647&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19048190%26dopt%3DAbstract In conclusion, bismuth stimulates eryptosis, the suicidal death of erythrocytes. The effect may contribute to or even account for the development of anemia during bismuth treatment. Moreover, ceramide formation in intestinal cells may participate in the therapeutic efficacy of bismuth preparations. PMID: 19048190 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=2007647 Tue, 02 Dec 2008 05:00:00 +0100 2007647 http://www.medworm.com/index.php?rid=2007646&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19048191%26dopt%3DAbstract Authors: Derocco AJ, Yost-Daljev MK, Kenney CD, Cornelissen CN The transferrin iron acquisition system of Neisseria gonorrhoeae consists of two dissimilar transferrin binding proteins (Tbp) A and B. TbpA is a TonB dependent transporter while TbpB is a lipoprotein that makes iron acquisition from transferrin (Tf) more efficient. In an attempt to further define the individual roles of these receptors in the process of Tf-iron acquisition, the kinetics of the receptor proteins in regards to ligand association and dissociation were evaluated. Tf association with TbpB was rapid as compared to TbpA. Tf dissociation from the wild-type receptor occurred in a biphasic manner; an initial rapid release was followed by a slower dissociation over time. Both TbpA and TbpB demonstrated a two-phase re... Biometals journals http://www.medworm.com/rss/comments.php?id=2007646 Tue, 02 Dec 2008 05:00:00 +0100 2007646 http://www.medworm.com/index.php?rid=1997364&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19039664%26dopt%3DAbstract Authors: Smith A, Rish KR, Lovelace R, Hackney JF, Helston RM Hemopexin (HPX) binds heme tightly, thus protecting cells from heme toxicity during hemolysis, trauma and ischemia-reperfusion injury. Heme uptake via endocytosis of heme-HPX followed by heme catabolism by heme oxygenase-1 (HMOX1) raises regulatory iron pools, thus linking heme metabolism with that of iron. Normal iron homeostasis requires copper-replete cells. When heme-HPX induces HMOX1, the copper-storing metallothioneins (MTs) are also induced whereas the copper-responsive copper chaperone that delivers copper to Cu, Zn superoxide dismutase, CCS1, is decreased; both are known responses when cellular copper levels rise. Endocytosis of heme-HPX is needed to regulate CCS1 since the signaling ligand cobalt-protoporphyrin (Co... Biometals journals http://www.medworm.com/rss/comments.php?id=1997364 Fri, 28 Nov 2008 05:00:00 +0100 1997364 http://www.medworm.com/index.php?rid=1944149&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18989627%26dopt%3DAbstract Authors: Kiranmayi P, Tiwari A, Sagar KP, Haritha A, Maruthi Mohan P Previous work from our laboratory involved the description of the Neurospora metal transportome, which included seven hypothetical zinc transporters belonging to the ZIP family. The aim of the present study was to make a comparative functional evaluation of two hypothetical zinc transporters named tzn1 (NCU07621.3) and tzn2 (NCU11414.3). Phenotypic analysis of tzn1 and tzn2 mutants and a double mutant (tzn1tzn2) revealed that the deletion of tzn1 causes aconidiation and a greater defect in growth than the single deletion of tzn2. Supplementation with zinc restores growth but not conidiation in tzn1 and tzn1tzn2. TZN1 complemented a zinc-uptake-deficient Saccharomyces cerevisiae mutant (zrt1zrt2) in zinc-deficient cond... Biometals journals http://www.medworm.com/rss/comments.php?id=1944149 Fri, 07 Nov 2008 05:00:00 +0100 1944149 http://www.medworm.com/index.php?rid=1940624&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18985279%26dopt%3DAbstract Authors: Grąz M, Jarosz-Wilkołazka A, Pawlikowska-Pawlęga B The ability of Abortiporus biennis to tolerate and solubilize toxic metal oxides (Cu(2)O, Al(2)O(3), ZnO, CuFe(2)O(4)Zn, CdO, and MnO(2)) incorporated into agar media was investigated and the growth rate, oxalic acid secretion, and mycelial morphology were monitored. Among the tested metal oxides, formation of clear zones underneath the mycelium growing on Cu(2)O- and ZnO-amended plates was observed. ZnO, CdO and Cu(2)O caused the highest rate of fungal growth inhibition. An increased level of oxalic acid concentration was detected as a response of A. biennis to the presence of Cu(2)O, MnO(2), ZnO and CuFe(2)O(4)Zn in growth medium. The oxalate oxidase (OXO) was found to be responsible for oxalic acid degrada... Biometals journals http://www.medworm.com/rss/comments.php?id=1940624 Wed, 05 Nov 2008 05:00:00 +0100 1940624 http://www.medworm.com/index.php?rid=1934962&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18982410%26dopt%3DAbstract Authors: Mello LD, Ribeiro ES, Kubota LT, Elmroth SK, Pereira RM The interaction of Pt(II)(dppf)-complex, namely [Pt(dppf)(H(2)O)(2)](2+) with DNA was investigated by DPV and (1)H-NMR techniques. The results showed that the interaction process has been characterized by changes in the electrochemical parameters of both compounds and the formation of a new anodic current peak close to the anodic current peak of the [Pt(dppf)(H(2)O)(2)](2+). In addition, the (1)H-NMR spectra show that the coordination of Pt(II)(dppf)-complex to dsDNA occurs via N(7) of guanine. Others parameters like pH and ionic strength that affect the interaction process were also investigated. PMID: 18982410 [PubMed - as supplied by publisher] (Source: Biometals) Biometals journals http://www.medworm.com/rss/comments.php?id=1934962 Tue, 04 Nov 2008 05:00:00 +0100 1934962 http://www.medworm.com/index.php?rid=1934961&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18982411%26dopt%3DAbstract Authors: Mladěnka P, Semecký V, Bobrovová Z, Nachtigal P, Vávrová J, Holečková M, Palicka V, Mazurová Y, Hrdina R Lactoferrin is recently under intense investigation because of its proposed several pharmacologically positive effects. Based on its iron-binding properties and its physiological presence in the human body, it may have a significant impact on pathological conditions associated with iron-catalysed reactive oxygen species (ROS). Its effect on a catecholamine model of myocardial injury, which shares several pathophysiological features with acute myocardial infarction (AMI) in humans, was examined. Male Wistar rats were randomly divided into four groups according to the received medication: control (saline), isoprenaline (ISO, 100 mg kg... Biometals journals http://www.medworm.com/rss/comments.php?id=1934961 Tue, 04 Nov 2008 05:00:00 +0100 1934961 http://www.medworm.com/index.php?rid=1931166&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18979168%26dopt%3DAbstract We present a structural model of CopA derived by combining topological information obtained by intramolecular cross-linking with molecular modeling. Purified CopA was cross-linked with different bivalent reagents, followed by tryptic digestion and identification of cross-linked peptides by mass spectrometry. The structural proximity of tryptic fragments provided information about the structural arrangement of the hydrophilic protein domains, which was integrated into a three-dimensional model of CopA. Comparative modeling of CopA was guided by the sequence similarity to the calcium ATPase of the sarcoplasmic reticulum, Serca1, for which detailed structures are available. In addition, known partial structures of CPx-ATPase homologous to CopA were used as modeling templates. A docking approa... Biometals journals http://www.medworm.com/rss/comments.php?id=1931166 Sat, 01 Nov 2008 04:00:00 +0100 1931166 http://www.medworm.com/index.php?rid=1915646&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18956143%26dopt%3DAbstract Authors: Majumder S, Chatterjee S, Pal S, Biswas J, Efferth T, Choudhuri SK Multidrug resistance (MDR) is still a major threat to successful clinical application of cancer chemotherapy. Copper plays an important role in biological systems, and copper is also involved in carcinogenesis. In the present investigation, we addressed the question whether metal copper might be involved in drug resistance of murine and human tumors. By means of atomic absorption spectroscopy, we determined serum copper concentrations. We found that the blood serum of tumor-bearing mice contained higher amounts of copper than healthy mice with tumors. Secondly, mice bearing doxorubicin-resistant Ehrlich ascites carcinoma- or cyclophosphamide-resistant Lewis lung carcinoma contained more copper in their serum th... Biometals journals http://www.medworm.com/rss/comments.php?id=1915646 Tue, 28 Oct 2008 04:00:00 +0100 1915646 http://www.medworm.com/index.php?rid=1915645&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18956144%26dopt%3DAbstract We examined the in vivo effect of iron deficiency on hepatic URO accumulation in experimental porphyria. Mice were fed diets containing low (iron-deficient diet (IDD), 8.5 mg iron/kg) or normal (normal diet (ND), 213.7 mg iron/kg) levels of iron. They were treated with 3-methylcholanthrene (MC), an archetypal inducer of CYP1A, and 5-aminolevulinate (ALA), precursors of porphyrin and heme. We found that uroporphyrin (URO) levels and uroporphyrinogen oxidation (UROX) activity were markedly increased in ND mice treated with MC and ALA, while the levels were not raised in IDD mice with the same treatments. CYP1A2 levels and methoxyresorufin O-demethylase (MROD) activities, the CYP1A2-mediated reaction, were markedly induced in the livers of both ND and IDD mice treated with MC and ALA. UROX ac... Biometals journals http://www.medworm.com/rss/comments.php?id=1915645 Tue, 28 Oct 2008 04:00:00 +0100 1915645 http://www.medworm.com/index.php?rid=1903148&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18946633%26dopt%3DAbstract Authors: Crosa LM, Crosa JH, Heffron F The mechanism of iron transport in Francisella is still a puzzle since none of the sequenced Francisella strains appears to encode a TonB protein, the energy transducer of the proton motive force necessary to act on the bacterial outer membrane siderophore receptor to allow the internalization of iron. In this work we demonstrate using kinetic experiments of radioactive Fe(3+) utilization, that iron uptake in Francisella novicida, although with no recognizable TonB protein, is indeed dependent on energy generated by the proton motive force. Moreover, mutants of a predicted outer membrane receptor still transport iron and are sensitive to the iron dependent antimicrobial compound streptonigrin. Our studies suggest that alternative pathways to inter... Biometals journals http://www.medworm.com/rss/comments.php?id=1903148 Thu, 23 Oct 2008 04:00:00 +0100 1903148 http://www.medworm.com/index.php?rid=1903149&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18941904%26dopt%3DAbstract In this study, we assessed the role of lanthanum chloride (LaCl(3)) in H(2)O(2)-enhanced calcification in rat calcifying vascular cells (CVCs) and examined the involvement of MAPK signaling pathways. H(2)O(2) induced growth inhibition of CVCs, as well as increases in intracellular levels of calcium and reactive oxygen species, ALP activity, apoptosis and calcium deposition. These effects of H(2)O(2) were suppressed by pretreatment of the cells with 1 muM of LaCl(3) for 2 h. In addition, H(2)O(2) activated the phosphorylation of ERK1/2, JNK and p38 MAPK, but only the last two were associated with the ALP activity. Our findings demonstrate that H(2)O(2)-enhanced osteoblastic differentiation and apoptosis are responsible for the increased calcification in rat CVCs, and LaCl(3) can counteract ... Biometals journals http://www.medworm.com/rss/comments.php?id=1903149 Wed, 22 Oct 2008 04:00:00 +0100 1903149 http://www.medworm.com/index.php?rid=1896661&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18937033%26dopt%3DAbstract Authors: Liapi C, Zarros A, Theocharis S, Al-Humadi H, Anifantaki F, Gkrouzman E, Mellios Z, Skandali N, Tsakiris S Lanthanum (La) is a rare earth element that is widely used for industrial, medical and agricultural purposes. Its neurotoxic effects are linked to its physical and chemical properties and its interaction with certain trace elements and membrane-bound enzymes. The aim of this study was to investigate the effects of short-term La-administration (as LaCl(3), 53 mg/kg) on the adult rat whole brain total antioxidant status (TAS) and the activities of acetylcholinesterase (AChE), Na(+),K(+)-ATPase and Mg(2+)-ATPase, as well as the potential effect of the co-administration of the antioxidant L: -cysteine (Cys, 7 mg/kg) on the above parameters. Twenty-eight male Wistar rats were ... Biometals journals http://www.medworm.com/rss/comments.php?id=1896661 Tue, 21 Oct 2008 04:00:00 +0100 1896661 http://www.medworm.com/index.php?rid=1896662&cid=s_37611_60_f&fid=37611&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18931919%26dopt%3DAbstract Authors: Jiang Q, Zhu J, Zhang Y, Xiao N, Guo Z Two zinc(II) terpyridine complexes Zn(atpy)(2)(PF(6))(2) (1) (atpy = 4'-p-N9'-adeninylmethylphenyl-2,2':6,2''-terpyridine) and Zn(ttpy)(2)(PF(6))(2) (2) (ttpy = 4'-p-tolyl-2,2':6,2''-terpyridine) have been synthesized and characterized by elemental analysis, (1)H NMR and electrospray mass spectroscopy. The structure of complex 2 was also determined by X-ray crystallography, which revealed a ZnN(6) coordination in an octahedral geometry with two terpyridine acting as equatorial ligands. The circular dichroism data showed that complex 1 exhibited an ICD signal at around 300 nm and induced more evident disturbances on DNA base stacking than complex 2, reflecting the impact of the adenine moiety on DNA binding modes. Complex 1 exhibited highe... Biometals journals http://www.medworm.com/rss/comments.php?id=1896662 Sat, 18 Oct 2008 04:00:00 +0100 1896662