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Sample records for iron binding capacity

  1. Total iron binding capacity

    Science.gov (United States)

    ... the intestines not properly absorbing vitamin B12 ( pernicious anemia ) Sickle cell anemia Risks There is very little risk involved with ... test Hemoglobin Hemolytic anemia Iron deficiency anemia Pernicious anemia Serum iron test Sickle cell anemia Review Date 2/11/2016 Updated by: ...

  2. Diagnostic Accuracy of Serum Iron and Total Iron Binding Capacity (TIBC) in Iron Deficiency State.

    Science.gov (United States)

    Asif, Naveed; Ijaz, Aamir; Rafi, Tariq; Haroon, Zujaja Hina; Bashir, Saima; Ayyub, Muhammad

    2016-12-01

    To determine the diagnostic accuracy of serum iron and total iron binding capacity (TIBC) in detection of iron deficiency. Descriptive, analytical study. Department of Chemical Pathology and Endocrinology, from January 2013 to October 2015. Data of 1,815 patients with results of serum iron, TIBC and ferritin from January 2013 to October 2015 was retrieved from Laboratory information System (LIMS) of AFIP. Diagnostic Accuracy Studies (STARD) guidelines were followed. Subjects of either gender, aged 1 - 68 years were included. Cases with raised serum ferritin levels (male > 336 ng/ml, female > 307 ng/ml) were excluded. Serum Ferritin was taken as gold standard with specificity of 99% and sensitivity of 80% at concentration of 30 ng/ml. Transferrin saturation was determined by dividing serum iron by TIBC and multiplying by 100. Out of 1,815 subjects, 931 (51.29%) were males and 884 (48.71%) were females. The median age of the patients were 29.1 years (Inter-quartile range, IQR 19.1). Taking ferritin as gold standard, the sensitivity and specificity of serum iron was 63.5% and 38.6%, respectively; while that of TIBC was 64.5 % and 42.8%, respectively. Ferritin showed poor correlation with iron, TIBC and transferrin saturation. Serum iron and TIBC give no additional information in the diagnosis of iron deficiency anemia and these tests are redundant for the diagnosis of iron deficiency state, if serum ferritin is available.

  3. Immunological measurement of transferrin compared with chemical measurement of total iron-binding capacity.

    Science.gov (United States)

    Tsung, S H; Rosenthal, W A; Milewski, K A

    1975-07-01

    Because of uncertainty as to the molecular weight of transferrin, a previous comparison [Von der Heul et al., Clin. Chim. Acta 38, 347 (1972)] between transferrin content of serum and total iron-binding capacity cannot be definitive. We found a conversion factor for expressing the maximum amount of iron bound by 1 mg of transferrin. We compared the resulting calculated value with values obtained by three other methods for measuring total iron-binding capacity. We agree with the previous observation that the latter, as measured radioisotopically, give higher results than would be judged from the transferrin content but the same as those for two chemical methods. The diffusion rate of transferrin in agar was the same irrespective of the degree of iron saturation. Serum transferrin concentrations were low in patients with anemia resulting from malignancy, chronic disorders, and cirrhosis of the liver, and high or normal in patients with iron deficiency anemia and in pregnant women or women who were taking birth-control pills. Measurement of transferrin concentration can be used to distinguish iron deficiency anemia from anemia resulting from chronic disorders, but offers no advantages over existing methods for estimating total iron-binding capacity.

  4. 21 CFR 862.1415 - Iron-binding capacity test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Iron-binding capacity test system. 862.1415 Section 862.1415 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  5. Evaluation of iron status in lemurs by analysis of serum iron and ferritin concentrations, total iron-binding capacity, and transferrin saturation.

    Science.gov (United States)

    Williams, Cathy V; Junge, Randall E; Stalis, Ilse H

    2008-02-15

    To assess serum iron and ferritin concentrations, total iron-binding capacity, and transferrin saturation as indicators of iron metabolic status in 3 genera of lemurs and determine whether these variables are useful for screening for iron overload. Cross-sectional study. 11 ring-tailed lemurs (Lemur catta), 11 black lemurs (Eulemur macaco macaco), and 11 red-ruffed lemurs (Varecia rubra). Blood samples were collected weekly for 3 weeks and assayed for serum iron and ferritin concentrations and total iron-binding capacity. Liver biopsy specimens were evaluated histologically and assayed for total iron, nonheme iron, and trace mineral concentrations. Deposition of iron was scored on Prussian blue-stained slides. Hepatic iron content ranged from 497 to 12,800 Pg/g dry weight (median, 2,165 Pg/g). Differences were seen in mean hepatic iron content across genera, with ruffed lemurs having the highest concentrations and ring-tailed lemurs having the lowest. Iron accumulation in the liver was mild, and cellular pathologic changes associated with iron storage disease were not detected in any lemur. Ferritin concentration was the only variable that correlated significantly with hepatic iron content in all 3 genera of lemurs; however, both transferrin saturation and serum iron concentration were correlated with hepatic iron concentration in ring-tailed and ruffed lemurs. Serum ferritin concentration was the only variable that was consistently correlated with hepatic iron content in all 3 genera. Mean hepatic iron content varied across genera, suggesting that the propensity for lemurs to develop iron overload in captivity may vary across taxa.

  6. Serum iron level, ferritin and total iron binding capacity level among nonpregnant women with and without melasma

    Directory of Open Access Journals (Sweden)

    Elham Behrangi

    2015-01-01

    Full Text Available Background: Melasma is a common acquired disorder characterized by symmetric, hyperpigmented patches with an irregular outline, occurring most commonly on the face. It is most prevalent among young to middle-aged women. Although iron overload affects skin pigmentation, effect of iron deficiency on skin is not clear. So, we evaluated serum iron level, ferritin and total iron binding capacity (TIBC level among nonpregnant women with and without melasma. Materials and Methods: A cross-sectional case study was conducted in 2012 at university dermatologic department on 33 nonpregnant women with melasma (case and 33 nonpregnant women without melasma (control. Serum iron level, TIBC and ferritin in the two groups was measured and compared. Results: Serum iron level was lower in the case group (85 ± 11 in comparison with control group (102 ± 9, but the difference was not significant (P: 0.9. Mean TIBC and Ferritin were higher in the case group (TIBC: 329.4 ± 29, ferritin: 6 ± 18 than the control group (TIBC: 329.3 ± 29, ferritin: 33 ± 6 without significant difference. Conclusion: Although the serum iron level was lower in nonpregnant women with mealsma, it was not significant compared with those without melasma.

  7. Serum iron level, ferritin and total iron binding capacity level among nonpregnant women with and without melasma

    Science.gov (United States)

    Behrangi, Elham; Baniasadi, Farzaneh; Esmaeeli, Shooka; Hedayat, Kosar; Goodarzi, Azade; Azizian, Zahra

    2015-01-01

    Background: Melasma is a common acquired disorder characterized by symmetric, hyperpigmented patches with an irregular outline, occurring most commonly on the face. It is most prevalent among young to middle-aged women. Although iron overload affects skin pigmentation, effect of iron deficiency on skin is not clear. So, we evaluated serum iron level, ferritin and total iron binding capacity (TIBC) level among nonpregnant women with and without melasma. Materials and Methods: A cross-sectional case study was conducted in 2012 at university dermatologic department on 33 nonpregnant women with melasma (case) and 33 nonpregnant women without melasma (control). Serum iron level, TIBC and ferritin in the two groups was measured and compared. Results: Serum iron level was lower in the case group (85 ± 11) in comparison with control group (102 ± 9), but the difference was not significant (P: 0.9). Mean TIBC and Ferritin were higher in the case group (TIBC: 329.4 ± 29, ferritin: 6 ± 18) than the control group (TIBC: 329.3 ± 29, ferritin: 33 ± 6) without significant difference. Conclusion: Although the serum iron level was lower in nonpregnant women with mealsma, it was not significant compared with those without melasma. PMID:26109976

  8. Suppression of serum iron-binding capacity and bone marrow cellularity in pigs fed aflatoxin

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, R.B.; Clark, D.E.; Huff, W.E.; Kubena, L.F.; Corrier, D.E. (USDA, College Station, TX (USA)); Phillips, T.D. (Texas A M Univ., College Station (USA))

    1988-05-01

    Flavus-parasiticus species of the genus Aspergillus are recognized as the primary producers of aflatoxins B{sub 1}, B{sub 2}, G{sub 1}, and G{sub 2}, hereafter referred to as aflatoxin (AF). The effects of feeding AF-contaminated diets to growing and finishing pigs have been described with changes in clinical performance, serum biochemistry, histology, and hematology attributed to aflatoxicosis. However, most of these studies evaluated AF-induced changes for a single AF dosage at a given point in time. The present study was designed to characterize how various AF dosages influence bone marrow histology, hematology, prothrombin and activated thromboplastin times, serum amino acids, and serum iron binding capacity during aflatoxicosis in growing pigs.

  9. Suppression of serum iron-binding capacity and bone marrow cellularity in pigs fed aflatoxin

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, R.B.; Clark, D.E.; Huff, W.E.; Kubena, L.F.; Corrier, D.E.; Phillips, I.D.

    1988-04-01

    Flavus-parasiticus species of the genus Aspergillus are recognized as the primary producers of aflatoxins B/sub 1/, B/sup 2/, G/sup 1/, and G/sup 2/, hereafter referred to as aflatoxin (AF). The effects of feeding AF-contaminated diets to growing and finishing pigs have been described with changes in clinical performance, serum biochemistry, histology, and hematology attributed to aflatoxicosis. However, most of these studies evaluated AF-induced changes for a single AF dosage at a given point in time. The present study was designed to characterize how various AF dosages influence bone marrow histology, hematology, prothrombin and activated thromboplastin times, serum amino acids, and serum iron binding capacity during aflatoxicosis in growing pigs.

  10. Colorimetry and constant-potential coulometry determinations of transferrin-bound iron, total iron-binding capacity, and total iron in serum containing iron-dextran, with use of sodium dithionite and alumina columns.

    Science.gov (United States)

    Jacobs, J C; Alexander, N M

    1990-10-01

    After the parenteral administration of iron-dextran (imferon), the increased total iron concentrations in serum can be determined by atomic absorption spectroscopy and by colorimetric methods involving sodium dithionite, which reductively dissociates iron from the dextran complex. We report that constant-potential coulometry detects only about 55-70% of dextran-bound iron before dithionite reduction and variable amounts after reaction with the reducing agent. In addition, we have developed a procedure for determining transferrin-bound iron, total iron-binding capacity (TIBC), total iron, and dextran-bound iron with the Kodak Ektachem colorimetric system. In determining total serum iron, the sample is first mixed with sodium dithionite, which rapidly dissociates all dextran-bound iron, but does not remove iron from either transferrin or hemoglobin. After the mixture is applied to an Ektachem slide, transferrin-bound iron is released at pH 4 and is detected together with the iron previously bound to dextran. TIBC is determined by mixing serum with ferric citrate in moderate excess and filtering through a small alumina (Al2O3) column, which binds excess free iron and iron-dextran; the iron in the column eluate represents the TIBC. Transferrin-bound iron is determined by applying diluted serum without added ferric citrate to an alumina column and measuring the iron in the column eluate. Dextran-bound iron is equivalent to the difference between total and transferrin-bound iron. Using this method, we found that transferrin iron-binding sites are saturated in vitro by excess iron-dextran less efficiently than by ferric citrate.

  11. Alteration of the Copper-Binding Capacity of Iron-Rich Humic Colloids during Transport from Peatland to Marine Waters.

    Science.gov (United States)

    Muller, François L L; Cuscov, Marco

    2017-02-28

    Blanket bogs contain vast amounts of Sphagnum-derived organic substances which can act as powerful chelators for dissolved iron and thus enhance its export to the coastal ocean. To investigate the variations in quantity and quality of these exports, adsorptive cathodic stripping voltammetry (CSV) was used to characterize the metal binding properties of molecular weight-fractionated dissolved organic matter (MW-fractionated DOM) in the catchment and coastal plume of a small peat-draining river over a seasonal cycle. Within the plume, both iron- and copper-binding organic ligands showed a linear, conservative distribution with increasing salinity, illustrating the high stability of peatland-derived humic substances (HS). Within the catchment, humic colloids lost up to 50% of their copper-binding capacity, expressed as a molar ratio to organic carbon, after residing for 1 week or more in the main reservoir of the catchment. Immediately downstream of the reservoir, the molar ratio [L2]/[Corg], where L2 was the second strongest copper-binding ligand, was 0.75 × 10(-4) when the reservoir residence time was 5 h but 0.34 × 10(-4) when it was 25 days. Residence time did not affect the carbon specific iron-binding capacity of the humic substances which was [L]/[Corg] = (0.80 ± 0.20) × 10(-2). Our results suggest that the loss of copper-binding capacity with increasing residence time is caused by intracolloidal interactions between iron and HS during transit from peat soil to river mouth.

  12. Effect of testosterone on hepcidin, ferroportin, ferritin and iron binding capacity in patients with hypogonadotropic hypogonadism and type 2 diabetes.

    Science.gov (United States)

    Dhindsa, Sandeep; Ghanim, Husam; Batra, Manav; Kuhadiya, Nitesh D; Abuaysheh, Sanaa; Green, Kelly; Makdissi, Antoine; Chaudhuri, Ajay; Dandona, Paresh

    2016-11-01

    As the syndrome of hypogonadotropic hypogonadism (HH) is associated with anaemia and the administration of testosterone restores haematocrit to normal, we investigated the potential underlying mechanisms. Randomized, double-blind, placebo-controlled trial. We measured basal serum concentrations of erythropoietin, iron, iron binding capacity, transferrin (saturated and unsaturated), ferritin and hepcidin and the expression of ferroportin and transferrin receptor (TR) in peripheral blood mononuclear cells (MNC) of 94 men with type 2 diabetes. Forty-four men had HH (defined as subnormal free testosterone along with low or normal LH concentrations) while 50 were eugonadal. Men with HH were randomized to testosterone or placebo treatment every 2 weeks for 15 weeks. Blood samples were collected at baseline, 3 and 15 weeks after starting treatment. Twenty men in testosterone group and 14 men in placebo group completed the study. Haematocrit levels were lower in men with HH (41·1 ± 3·9% vs 43·8 ± 3·4%, P = 0·001). There were no differences in plasma concentrations of hepcidin, ferritin, erythropoietin, transferrin or iron, or in the expression of ferroportin or TR in MNC among HH and eugonadal men. Haematocrit increased to 45·3 ± 4·5%, hepcidin decreased by 28 ± 7% and erythropoietin increased by 21 ± 7% after testosterone therapy (P ferritin concentrations, but transferrin concentration increased while transferrin saturation and iron concentrations decreased (P < 0·05). Ferroportin and TR mRNA expression in MNC increased by 70 ± 13% and 43 ± 10%, respectively (P < 0·01), after testosterone therapy. The increase in haematocrit following testosterone therapy is associated with an increase in erythropoietin, the suppression of hepcidin, and an increase in the expression of ferroportin and TR. © 2016 John Wiley & Sons Ltd.

  13. Evaluation of iron metabolism indices and their relation with physical work capacity in athletes.

    OpenAIRE

    Karamizrak, S O; Işlegen, C; Varol, S R; Taşkiran, Y; Yaman, C; Mutaf, I; Akgün, N

    1996-01-01

    OBJECTIVE--To evaluate the relation between iron status and physical working capacity, and to assess the effect of oral iron treatment on these variables, in athletes with borderline iron status. METHODS--Blood haemoglobin (Hb), packed cell volume (PCV), red blood cell count (RBC), serum iron, total iron binding capacity (TIBC), and ferritin determinations were compared in 71 male and 18 female athletes participating in various sports and in matched male (n = 11) and female (n = 8) controls. ...

  14. Iron-binding properties of sugar cane yeast peptides.

    Science.gov (United States)

    de la Hoz, Lucia; Ponezi, Alexandre N; Milani, Raquel F; Nunes da Silva, Vera S; Sonia de Souza, A; Bertoldo-Pacheco, Maria Teresa

    2014-01-01

    The extract of sugar-cane yeast (Saccharomyces cerevisiae) was enzymatically hydrolysed by Alcalase, Protex or Viscozyme. Hydrolysates were fractionated using a membrane ultrafiltration system and peptides smaller than 5kDa were evaluated for iron chelating ability through measurements of iron solubility, binding capacity and dialyzability. Iron-chelating peptides were isolated using immobilized metal affinity chromatography (IMAC). They showed higher content of His, Lys, and Arg than the original hydrolysates. In spite of poor iron solubility, hydrolysates of Viscozyme provided higher iron dialyzability than those of other enzymes. This means that more chelates of iron or complexes were formed and these kept the iron stable during simulated gastro-intestinal digestion in vitro, improving its dialyzability.

  15. Binding capacity: cooperativity and buffering in biopolymers.

    Science.gov (United States)

    Di Cera, E; Gill, S J; Wyman, J

    1988-01-01

    The group of linkage potentials resulting from the energy of a physicochemical system expressed per mol of a reference component, say a polyfunctional macromolecule, leads to the concept of binding capacity. This concept applies equally to both chemical and physical ligands and opens the way to consideration of higher-order linkage relationships. It provides a means of exploring the consequences of thermodynamic stability on generalized binding phenomena in biopolymers. PMID:3422436

  16. METABOLIC CAPACITY REGULATES IRON HOMEOSTATIS IN ENDOTHELIAL CELLS

    Science.gov (United States)

    The sensitivity of endothelial cells to oxidative stress and the high concentrations of iron in mitochondria led us to test the hypotheses that (1) changes in respiratory capacity alter iron homeostasis, and (2) lack of aerobic metabolism decreases labile iron stores and attenuat...

  17. The Sulfide Capacity of Iron Oxide-Rich Slags

    Science.gov (United States)

    Motlagh, M.

    1988-03-01

    The relationship between the sulfide capacity of slags rich in iron oxide and the sulfur partition ratio between the metal and slag is strongly related to the slag's iron oxide concentration. For slags containing little or no lime, this relationship is linear for a constant concentration of iron oxide in the slag. The effect of silica on changes in the sulfide capacity of slags rich in iron oxide is similar to that of basic steel-making slags, particularly at low activity of silica in slag.

  18. Synthetic Detergents: Their Influence upon Iron-Binding Complexes of Natural Waters.

    Science.gov (United States)

    Kent, F; Hooper, F F

    1966-07-29

    Organic compounds extracted from Michigan lakes and streams and added to algal cultures increase the growth rate of the green alga (Chlamydomonas reinhardi) when iron is present. Two-dimensional paper chromatography has shown that the iron is complexed by organic fractions containing an amine group. When isolated from natural waters containing a concentration of over 0.3 part per million alkyl benzene sulfonate, these compounds do not show an iron-binding capacity. Separation of this sulfonate from the amine complexes restores the iron-binding capability. These findings suggest that detergents may influence the mobility of iron by reducing the number of binding sites, and in this way may have an important secondary effect upon the primary production of lakes and streams.

  19. Iron-binding haemerythrin RING ubiquitin ligases regulate plant iron responses and accumulation

    Science.gov (United States)

    Kobayashi, Takanori; Nagasaka, Seiji; Senoura, Takeshi; Itai, Reiko Nakanishi; Nakanishi, Hiromi; Nishizawa, Naoko K.

    2013-01-01

    Iron is essential for most living organisms. Plants transcriptionally induce genes involved in iron acquisition under conditions of low iron availability, but the nature of the deficiency signal and its sensors are unknown. Here we report the identification of new iron regulators in rice, designated Oryza sativa Haemerythrin motif-containing Really Interesting New Gene (RING)- and Zinc-finger protein 1 (OsHRZ1) and OsHRZ2. OsHRZ1, OsHRZ2 and their Arabidopsis homologue BRUTUS bind iron and zinc, and possess ubiquitination activity. OsHRZ1 and OsHRZ2 are susceptible to degradation in roots irrespective of iron conditions. OsHRZ-knockdown plants exhibit substantial tolerance to iron deficiency, and accumulate more iron in their shoots and grains irrespective of soil iron conditions. The expression of iron deficiency-inducible genes involved in iron utilization is enhanced in OsHRZ-knockdown plants, mostly under iron-sufficient conditions. These results suggest that OsHRZ1 and OsHRZ2 are iron-binding sensors that negatively regulate iron acquisition under conditions of iron sufficiency. PMID:24253678

  20. Iron Test

    Science.gov (United States)

    ... as: Serum Iron; Serum Fe Formal name: Iron, serum Related tests: Ferritin ; TIBC, UIBC and Transferrin ; Hemoglobin ; Hematocrit ; Complete Blood Count ; Reticulocyte Count ; Zinc Protoporphyrin ; Iron Tests ; Soluble Transferrin Receptor ... I should know? How is it used? Serum iron, total iron-binding capacity (TIBC) , and/or ...

  1. Iron-binding E3 ligase mediates iron response in plants by targeting basic helix-loop-helix transcription factors.

    Science.gov (United States)

    Selote, Devarshi; Samira, Rozalynne; Matthiadis, Anna; Gillikin, Jeffrey W; Long, Terri A

    2015-01-01

    Iron uptake and metabolism are tightly regulated in both plants and animals. In Arabidopsis (Arabidopsis thaliana), BRUTUS (BTS), which contains three hemerythrin (HHE) domains and a Really Interesting New Gene (RING) domain, interacts with basic helix-loop-helix transcription factors that are capable of forming heterodimers with POPEYE (PYE), a positive regulator of the iron deficiency response. BTS has been shown to have E3 ligase capacity and to play a role in root growth, rhizosphere acidification, and iron reductase activity in response to iron deprivation. To further characterize the function of this protein, we examined the expression pattern of recombinant ProBTS::β-GLUCURONIDASE and found that it is expressed in developing embryos and other reproductive tissues, corresponding with its apparent role in reproductive growth and development. Our findings also indicate that the interactions between BTS and PYE-like (PYEL) basic helix-loop-helix transcription factors occur within the nucleus and are dependent on the presence of the RING domain. We provide evidence that BTS facilitates 26S proteasome-mediated degradation of PYEL proteins in the absence of iron. We also determined that, upon binding iron at the HHE domains, BTS is destabilized and that this destabilization relies on specific residues within the HHE domains. This study reveals an important and unique mechanism for plant iron homeostasis whereby an E3 ubiquitin ligase may posttranslationally control components of the transcriptional regulatory network involved in the iron deficiency response.

  2. Phosphate binding by natural iron-rich colloids in streams

    NARCIS (Netherlands)

    Baken, S.; Moens, C.; Griffioen, J.J.; Smolders, E.

    2016-01-01

    Phosphorus (P) in natural waters may be bound to iron (Fe) bearing colloids. However, the natural variation in composition and P binding strength of these colloids remain unclear. We related the composition of "coarse colloids" (colloids in the 0.1-1.2 μm size range) in 47 Belgian streams to the

  3. Phosphate binding by natural iron-rich colloids in streams

    NARCIS (Netherlands)

    Baken, S.; Moens, C.; Griffioen, J.J.; Smolders, E.

    2016-01-01

    Phosphorus (P) in natural waters may be bound to iron (Fe) bearing colloids. However, the natural variation in composition and P binding strength of these colloids remain unclear. We related the composition of "coarse colloids" (colloids in the 0.1-1.2 μm size range) in 47 Belgian streams to the che

  4. Binding Affinity and Capacity for the Uremic Toxin Indoxyl Sulfate

    Directory of Open Access Journals (Sweden)

    Eric Devine

    2014-01-01

    Full Text Available Protein binding prevents uremic toxins from removal by conventional extracorporeal therapies leading to accumulation in maintenance dialysis patients. Weakening of the protein binding may enhance the dialytic elimination of these toxins. In ultrafiltration and equilibrium dialysis experiments, different measures to modify the plasma binding affinity and capacity were tested: (i, increasing the sodium chloride (NaCl concentration to achieve a higher ionic strength; (ii, increasing the temperature; and (iii, dilution. The effects on the dissociation constant KD and the protein bound fraction of the prototypical uremic toxin indoxyl sulfate (IS in plasma of healthy and uremic individuals were studied. Binding of IS corresponded to one site binding in normal plasma. KD increased linearly with the NaCl concentration between 0.15 (KD = 13.2 ± 3.7 µM and 0.75 M (KD = 56.2 ± 2.0 µM. Plasma dilution further reduced the protein bound toxin fraction by lowering the protein binding capacity of the plasma. Higher temperatures also decreased the protein bound fraction of IS in human plasma. Increasing the NaCl concentration was effective to weaken the binding of IS also in uremic plasma: the protein bound fraction decreased from 89% ± 3% to 81% ± 3% at 0.15 and 0.75 M NaCl, respectively. Dilution and increasing the ionic strength and temperature enhance the free fraction of IS allowing better removal of the substance during dialysis. Applied during clinical dialysis, this may have beneficial effects on the long-term outcome of maintenance dialysis patients.

  5. [Larval stages of Ascaris lumbricoides: hyaluronan-binding capacity].

    Science.gov (United States)

    Ponce-León, Patricia; Foresto, Patricia; Valverde, Juana

    2009-03-01

    Hyaluronic acid has important functions in inflammatory and tissue reparation processes. Owing to the varied strategies of the parasites to evade the host's immune response, as well as the multiple functions and physiological importance of hyaluronic acid, the aim was to study the hyaluronan binding capacity by Ascaris lumbricoides larval stages. Larval concentrates were prepared by hatching A. lumbricoides eggs. The larvae were collected by the Baermann method. The test of serum soluble CD44 detection by Agregation Inhibition was modified. All the larval concentrates presented hyaluronan binding capacity. The obtained results allow to suppose the existence of an hyaluronic acid specific receptor in A. lumbricoides. This receptor eventually might compete with the usual receptors of the host. The parasite might use this mechanism to evade the immune response.

  6. Optimization of Hydrolysis Conditions for the Production of Iron-Binding Peptides from Mackerel Processing Byproducts

    Directory of Open Access Journals (Sweden)

    Pan-Feng Wang

    2013-07-01

    Full Text Available The aim of this study was focused on optimization of enzymatic hydrolysis conditions for the production of iron-binding peptides from marine mackerel processing byproducts. The marine mackerel processing byproducts protein were hydrolyzed using trypsin, Protamex, Flavourzyme, Alcalase and Neutrase. Alcalase and Protamex proteolytic hydrolysates exhibited the highest iron-binding capacity; however, Alcalase proteolytic hydrolysate had higher degree of hydrolysis than that of Protamex. A four-factor-three-level composition central design experiment in response surface methodology was used to optimize the enzymatic hydrolysis conditions of Alcalase. The optimal enzymatic hydrolysis conditions were temperature of 46.0°C, time of 2.01 h, pH 8.35 and enzyme to substrate 6460 U/mL. The quadratic model predicted well about the actual measured value. The average iron-binding capacity of three verification experiment was 6.62 mg-EDTA/g-protein, which was much closed to model predicted value of 6.69 mg-EDTA/g-protein.

  7. Aging of iron (hydr)oxides by heat treatment and effects on heavy metal binding

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Starckpoole, M. M.; Frenkel, A. I.

    2000-01-01

    Amorphous iron (hydr)oxides are used to remove heavy metals from wastewater and in the treatment of air pollution control residues generated in waste incineration. In this study, iron oxides containing heavy metals (e.g., Pb, Hg, Cr, and Cd) were treated at 50, 600, and 900 °C to simulate...... oxides were transformed to hematite, which had a greater thermodynamic stability but less surface area than the initial products. Heat treatment also caused some volatilization of heavy metals (most notably, Hg). Leaching with water at pH 9 (L/S 10, 24 h) and weak acid extraction showed that heat...... of iron oxides may be advantageous to improve the thermodynamic stability of the product but that thermal treatment at both 600 and 900 °C significantly reduced the binding capacity for heavy metals....

  8. An iron-binding Trypanosoma cruzi urinary antigen.

    Science.gov (United States)

    Corral, R S; Bertot, G M; Petray, P B; Altcheh, J M; Singh, M; Orn, A; Rapoport, M F; Grinstein, S

    1995-12-01

    An 80-kDa Trypanosoma cruzi urinary antigen (UAg) was affinity-purified from the urine of infected dogs. We demonstrated that UAg is structurally and functionally related to proteins belonging to the transferrin family, as shown by amino acid sequence and iron binding experiments. Nevertheless, monoclonal antibodies raised against UAg specifically and selectively recognized this parasite's circulating antigen. The existence of an 80-kDa T. cruzi antigen co-migrating with UAg could be confirmed when epimastigotes were metabolically labelled with [35S] methionine and then immunoprecipitated with the above mentioned antibodies. We conclude that UAg is an iron-binding T. cruzi component eliminated in the urine of the infected host.

  9. Tracking inhomogeneity in high-capacity lithium iron phosphate batteries

    Science.gov (United States)

    Paxton, William A.; Zhong, Zhong; Tsakalakos, Thomas

    2015-02-01

    Energy-dispersive x-ray diffraction (EDXRD) is one of the few techniques that can internally probe a sealed battery under operating conditions. In this paper, we use EDXRD with ultrahigh energy synchrotron radiation to track inhomogeneity in a cycled high-capacity lithium iron phosphate cell under in-situ and operando conditions. A sequence of depth-profile x-ray diffraction spectra are collected with 40 μm resolution as the cell is discharged. Additionally, nine different locations of the cell are tracked independently throughout a second discharge process. In each case, a two-peak reference intensity ratio analysis (RIR) was used on the LiFePO4 311 and the FePO4 020 reflections to estimate the relative phase abundance of the lithiated and non-lithiated phases. The data provide a first-time look at the dynamics of electrochemical inhomogeneity in a real-world battery. We observe a strong correlation between inhomogeneity and overpotential in the galvanic response of the cell. Additionally, the data closely follow the behavior that is predicted by the resistive-reactant model originally proposed by Thomas-Alyea. Despite a non-linear response in the independently measured locations, the behavior of the ensemble is strikingly linear. This suggests that effects of inhomogeneity can be elusive and highlights the power of the EDXRD technique.

  10. Co-regulation of Iron Metabolism and Virulence Associated Functions by Iron and XibR, a Novel Iron Binding Transcription Factor, in the Plant Pathogen Xanthomonas.

    Science.gov (United States)

    Pandey, Sheo Shankar; Patnana, Pradeep Kumar; Lomada, Santosh Kumar; Tomar, Archana; Chatterjee, Subhadeep

    2016-11-01

    Abilities of bacterial pathogens to adapt to the iron limitation present in hosts is critical to their virulence. Bacterial pathogens have evolved diverse strategies to coordinately regulate iron metabolism and virulence associated functions to maintain iron homeostasis in response to changing iron availability in the environment. In many bacteria the ferric uptake regulator (Fur) functions as transcription factor that utilize ferrous form of iron as cofactor to regulate transcription of iron metabolism and many cellular functions. However, mechanisms of fine-tuning and coordinated regulation of virulence associated function beyond iron and Fur-Fe2+ remain undefined. In this study, we show that a novel transcriptional regulator XibR (named Xanthomonas iron binding regulator) of the NtrC family, is required for fine-tuning and co-coordinately regulating the expression of several iron regulated genes and virulence associated functions in phytopathogen Xanthomonas campestris pv. campestris (Xcc). Genome wide expression analysis of iron-starvation stimulon and XibR regulon, GUS assays, genetic and functional studies of xibR mutant revealed that XibR positively regulates functions involved in iron storage and uptake, chemotaxis, motility and negatively regulates siderophore production, in response to iron. Furthermore, chromatin immunoprecipitation followed by quantitative real-time PCR indicated that iron promoted binding of the XibR to the upstream regulatory sequence of operon's involved in chemotaxis and motility. Circular dichroism spectroscopy showed that purified XibR bound ferric form of iron. Electrophoretic mobility shift assay revealed that iron positively affected the binding of XibR to the upstream regulatory sequences of the target virulence genes, an effect that was reversed by ferric iron chelator deferoxamine. Taken together, these data revealed that how XibR coordinately regulates virulence associated and iron metabolism functions in Xanthomonads in

  11. Formation and characterization of iron-binding phosphorylated human-like collagen as a potential iron supplement

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jianjun; Chen, Fei; Fan, Daidi, E-mail: fandaidi@nwu.edu.cn; Zhu, Chenhui; Ma, Xiaoxuan; Xue, Wenjiao

    2013-10-01

    Iron incorporated into food can induce precipitation and unwanted interaction with other components in food. Iron-binding proteins represent a possibility to avoid these problems and other side effects, as the iron is protected. However, there are several technical problems associated with protein–iron complex formation. In this paper, the iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared under physiological conditions through phosphorylated modification. One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. Spectroscopy analysis, differential scanning calorimetry (DSC) and equilibrium dialysis techniques were employed to investigate the characteristics of the Fe-G6P-HLC. The binding sites (n{sub b}) and apparent association constant (K{sub app}) between iron and phosphorylated HLC were measured at n{sub b} = 23.7 and log K{sub app} = 4.57, respectively. The amount of iron (Fe{sup 2+} sulfate) binding to phosphorylated HLC was found to be a function of pH and phosphate content. In addition, the solubility and thermal stability of HLC were not significantly affected. The results should facilitate the utilization of HLC as a bioactive iron supplement in the food and medical industry and provide an important theoretical evidence for the application of HLC chelates. - Highlights: • The iron-binding phosphorylated human-like collagen (Fe-G6P-HLC) was prepared. • One molecule of Fe-G6P-HLC possesses about 24 atoms of Fe. • The binding properties could be modulated through alterations in pH and phosphate content presented in HLC. • A novel strategy for preparing iron-binding proteins was provided.

  12. Influence of Four Factors on Discharge Capacity and Self-Discharge Rate of Iron Electrode

    Institute of Scientific and Technical Information of China (English)

    Dongfeng LIN; Shihai YE; Rong CAI; Deying SONG; Panwen SHEN

    2003-01-01

    Ni-Fe rechargeable batteries possess the advantages of long cycle life, high theoretical specific energy, abundant raw material,Iow price and environmental friendship. It has a wide applied perspective. The advantages, disadvantages and preparation methods of iron electrodes were summarized. The influence of four factors on discharge capacity and self-discharge rate of iron electrode were discussed by means of orthogonal experiments, galvanostatic charges and discharges. The influences of graphite on the discharge capacity and self-discharge rate of iron electrode were the most remarkable, the most unapparent influences on the discharge capacity and self-discharge rate were HPMC (hydroxy propoxy methoxy cellulose) and sodium sulphide, respectively. The aim of the present research was to study the effects of graphite, HPMC and iron powder added in the electrodes, sodium sulphide added in the electrolytes on the discharge capacity and self-discharge rate of iron electrodes.The largest discharge capacity of the iron electrodes was 488.5 mAh/g-Fe at 66.4 mA/g-Fe in the first ten cycles, and the average self-discharge rate was 0.367% per hour.

  13. Iron binding at specific sites within the octameric HbpS protects streptomycetes from iron-mediated oxidative stress.

    Directory of Open Access Journals (Sweden)

    Ina Wedderhoff

    Full Text Available The soil bacterium Streptomyces reticuli secretes the octameric protein HbpS that acts as a sensory component of the redox-signalling pathway HbpS-SenS-SenR. This system modulates a genetic response on iron- and haem-mediated oxidative stress. Moreover, HbpS alone provides this bacterium with a defence mechanism to the presence of high concentrations of iron ions and haem. While the protection against haem has been related to its haem-binding and haem-degrading activity, the interaction with iron has not been studied in detail. In this work, we biochemically analyzed the iron-binding activity of a set of generated HbpS mutant proteins and present evidence showing the involvement of one internal and two exposed D/EXXE motifs in binding of high quantities of ferrous iron, with the internal E78XXE81 displaying the tightest binding. We additionally show that HbpS is able to oxidize ferrous to ferric iron ions. Based on the crystal structure of both the wild-type and the mutant HbpS-D78XXD81, we conclude that the local arrangement of the side chains from the glutamates in E78XXE81 within the octameric assembly is a pre-requisite for interaction with iron. The data obtained led us to propose that the exposed and the internal motif build a highly specific route that is involved in the transport of high quantities of iron ions into the core of the HbpS octamer. Furthermore, physiological studies using Streptomyces transformants secreting either wild-type or HbpS mutant proteins and different redox-cycling compounds led us to conclude that the iron-sequestering activity of HbpS protects these soil bacteria from the hazardous side effects of peroxide- and iron-based oxidative stress.

  14. Iron Status in Chronic Heart Failure: Impact on Symptoms, Functional Class and Submaximal Exercise Capacity.

    Science.gov (United States)

    Enjuanes, Cristina; Bruguera, Jordi; Grau, María; Cladellas, Mercé; Gonzalez, Gina; Meroño, Oona; Moliner-Borja, Pedro; Verdú, José M; Farré, Nuria; Comín-Colet, Josep

    2016-03-01

    To evaluate the effect of iron deficiency and anemia on submaximal exercise capacity in patients with chronic heart failure. We undertook a single-center cross-sectional study in a group of stable patients with chronic heart failure. At recruitment, patients provided baseline information and completed a 6-minute walk test to evaluate submaximal exercise capacity and exercise-induced symptoms. At the same time, blood samples were taken for serological evaluation. Iron deficiency was defined as ferritin < 100 ng/mL or transferrin saturation < 20% when ferritin is < 800 ng/mL. Additional markers of iron status were also measured. A total of 538 heart failure patients were eligible for inclusion, with an average age of 71 years and 33% were in New York Heart Association class III/IV. The mean distance walked in the test was 285 ± 101 meters among those with impaired iron status, vs 322 ± 113 meters (P=.002). Symptoms during the test were more frequent in iron deficiency patients (35% vs 27%; P=.028) and the most common symptom reported was fatigue. Multivariate logistic regression analyses showed that increased levels of soluble transferrin receptor indicating abnormal iron status were independently associated with advanced New York Heart Association class (P < .05). Multivariable analysis using generalized additive models, soluble transferrin receptor and ferritin index, both biomarkers measuring iron status, showed a significant, independent and linear association with submaximal exercise capacity (P=.03 for both). In contrast, hemoglobin levels were not significantly associated with 6-minute walk test distance in the multivariable analysis. In patients with chronic heart failure, iron deficiency but not anemia was associated with impaired submaximal exercise capacity and symptomatic functional limitation. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  15. Calcium-binding capacity of organic and inorganic ortho- and polyphosphates

    NARCIS (Netherlands)

    Kort, de E.J.P.; Minor, M.; Snoeren, T.H.M.; Hooijdonk, van A.C.M.; Linden, van der E.

    2009-01-01

    The aim of this research was to determine the calcium-binding capacity of inorganic and organic ortho- and polyphosphates. This calcium-binding capacity can be used to influence the stability of, for example, casein micelles in dairy systems. Four phosphates were selected: disodium uridine

  16. Iron-binding ligands in the southern California Current System: mechanistic studies

    Directory of Open Access Journals (Sweden)

    Randelle M Bundy

    2016-03-01

    Full Text Available The distributions of dissolved iron and organic iron-binding ligands were examined in water column profiles and deckboard incubation experiments in the southern California Current System (sCCS along a transition from coastal to semi-oligotrophic waters. Analysis of the iron-binding ligand pool by competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV using multiple analytical windows (MAWs revealed three classes of iron-binding ligands present throughout the water column (L1-L3, whose distributions closely matched those of dissolved iron and nitrate. Despite significant biogeochemical gradients, ligand profiles were similar between stations, with surface minima in strong ligands (L1 and L2, and relatively constant concentrations of weaker ligands (L3 down to 500 m. A phytoplankton grow-out incubation, initiated from an iron-limited water mass, showed dynamic temporal cycling of iron-binding ligands. A biological iron model was able to capture the patterns of the strong ligands in the grow-out incubation relatively well with only the microbial community as a biological source. An experiment focused on remineralization of particulate organic matter showed production of both strong and weak iron-binding ligands by the heterotrophic community, supporting a mechanism for in-situ production of both strong and weak iron-binding ligands in the subsurface water column. Photochemical experiments showed a variable influence of sunlight on the degradation of natural iron-binding ligands, providing some evidence to explain differences in surface ligand concentrations between stations. Patterns in ligand distributions between profiles and in the incubation experiments were primarily related to macronutrient concentrations, suggesting microbial remineralization processes might dominate on longer time-scales over short-term changes associated with photochemistry or phytoplankton growth.

  17. Routes to improve binding capacities of affinity resins demonstrated for Protein A chromatography.

    Science.gov (United States)

    Müller, Egbert; Vajda, Judith

    2016-05-15

    Protein A chromatography is a well-established platform in downstream purification of monoclonal antibodies. Dynamic binding capacities are continuously increasing with almost every newly launched Protein A resin. Nevertheless, binding capacities of affinity chromatography resins cannot compete with binding capacities obtained with modern ion exchange media. Capacities of affinity resins are roughly 50% lower. High binding capacities of ion exchange media are supported by spacer technologies. In this article, we review existing spacer technologies of affinity chromatography resins. A yet known effective approach to increase the dynamic binding capacity of Protein A resins is oligomerization of the particular Protein A motifs. This resembles the tentacle technology used in ion exchange chromatography. Dynamic binding capacities of a hexameric ligand are roughly twice as high compared to capacities obtained with a tetrameric ligand. Further capacity increases up to 130mg/ml can be realized with the hexamer ligand, if the sodium phosphate buffer concentration is increased from 20 to 100mM. Equilibrium isotherms revealed a BET shape for the hexamer ligand at monoclonal antibody liquid phase concentrations higher than 9mg/ml. The apparent multilayer formation may be due to hydrophobic forces. Other quality attributes such as recovery, aggregate content, and overall purity of the captured monoclonal antibody are not affected.

  18. Detection of iron(III)-binding ligands originating from marine phytoplankton using cathodic stripping voltammetry.

    Science.gov (United States)

    Hasegawa, Hiroshi; Maki, Teruya; Asano, Kohnosuke; Ueda, Kentaro; Ueda, Kazumasa

    2004-01-01

    The sample preparation and analytical methodology are described for detecting biologically produced iron(III)-binding ligands in laboratory cultures of coastal marine phytoplankton. The iron(III)-binding ligands from the culture media were purified by passage through a column packing with a hydrophobic absorbent. The concentrations and stability constants of the ligands were determined by adsorptive cathodic stripping voltammetry with competitive ligand equilibration. The analytical results of the cultivated cultures suggest that eukaryotic phytoplankton would produce iron(III)-binding ligands in analogy with other microorganisms.

  19. An iron-binding protein, Dpr, from Streptococcus mutans prevents iron-dependent hydroxyl radical formation in vitro.

    Science.gov (United States)

    Yamamoto, Yuji; Poole, Leslie B; Hantgan, Roy R; Kamio, Yoshiyuki

    2002-06-01

    The dpr gene is an antioxidant gene which was isolated from the Streptococcus mutans chromosome by its ability to complement an alkyl hydroperoxide reductase-deficient mutant of Escherichia coli, and it was proven to play an indispensable role in oxygen tolerance in S. mutans. Here, we purified the 20-kDa dpr gene product, Dpr, from a crude extract of S. mutans as an iron-binding protein and found that Dpr formed a spherical oligomer about 9 nm in diameter. Molecular weight determinations of Dpr in solution by analytical ultracentrifugation and light-scattering analyses gave values of 223,000 to 292,000, consistent with a subunit composition of 11.5 to 15 subunits per molecule. The purified Dpr contained iron and zinc atoms and had an ability to incorporate up to 480 iron and 11.2 zinc atoms per molecule. Unlike E. coli Dps and two other members of the Dps family, Dpr was unable to bind DNA. One hundred nanomolar Dpr prevented by more than 90% the formation of hydroxyl radical generated by 10 microM iron(II) salt in vitro. The data shown in this study indicate that Dpr may act as a ferritin-like iron-binding protein in S. mutans and may allow this catalase- and heme-peroxidase-deficient bacterium to grow under air by limiting the iron-catalyzed Fenton reaction.

  20. Iron uptake and increased intracellular enzyme activity follow host lactoferrin binding by Trichomonas vaginalis receptors

    OpenAIRE

    1984-01-01

    Lactoferrin acquisition and iron uptake by pathogenic Trichomonas vaginalis was examined. Saturation binding kinetics were obtained for trichomonads using increasing amounts of radioiodinated lactoferrin, while no significant binding by transferrin under similar conditions was achieved. Only unlabeled lactoferrin successfully and stoichiometrically competed with 125I-labeled lactoferrin binding. Time course studies showed maximal lactoferrin binding by 30 min at 37 degrees C. Data suggest no ...

  1. Host iron binding proteins acting as niche indicators for Neisseria meningitidis.

    Directory of Open Access Journals (Sweden)

    Philip W Jordan

    Full Text Available Neisseria meningitidis requires iron, and in the absence of iron alters its gene expression to increase iron acquisition and to make the best use of the iron it has. During different stages of colonization and infection available iron sources differ, particularly the host iron-binding proteins haemoglobin, transferrin, and lactoferrin. This study compared the transcriptional responses of N. meningitidis, when grown in the presence of these iron donors and ferric iron, using microarrays.Specific transcriptional responses to the different iron sources were observed, including genes that are not part of the response to iron restriction. Comparisons between growth on haemoglobin and either transferrin or lactoferrin identified changes in 124 and 114 genes, respectively, and 33 genes differed between growth on transferrin or lactoferrin. Comparison of gene expression from growth on haemoglobin or ferric iron showed that transcription is also affected by the entry of either haem or ferric iron into the cytoplasm. This is consistent with a model in which N. meningitidis uses the relative availability of host iron donor proteins as niche indicators.Growth in the presence of haemoglobin is associated with a response likely to be adaptive to survival within the bloodstream, which is supported by serum killing assays that indicate growth on haemoglobin significantly increases survival, and the response to lactoferrin is associated with increased expression of epithelial cell adhesins and oxidative stress response molecules. The transferrin receptor is the most highly transcribed receptor and has the fewest genes specifically induced in its presence, suggesting this is the favoured iron source for the bacterium. Most strikingly, the responses to haemoglobin, which is associated with unrestricted growth, indicates a low iron transcriptional profile, associated with an aggressive phenotype that may be adaptive to access host iron sources but which may also

  2. 针刺提插补泻法对血虚证模型家兔血清铁蛋白、总铁结合力的影响%Effect of Lifting-thrusting Reinforcing-reducing Manipulations of Acupuncture on Serum Ferritin Content and Total Iron Binding Capacity in Blood-deficiency Syndrome Rabbits

    Institute of Scientific and Technical Information of China (English)

    徐敏; 许安萍; 睢明河

    2012-01-01

    Objective To observe the influence of lift-thrust reinforcing-reducing manipulations of acupuncture on serum ferritin (SF) content and total iron binding capacity (TIBC) in blood-deficiency syndrome rabbits so as to study its underlying mechanisms. Methods Sixty Japanese white rabbits were randomized into blank control,model. Acupuncture needle-retaining, reinforcing-manipulation (reinforcing) and reducing-manipulation (reducing) groups (n = 12 in each group). Blood-deficiency syndrome model was duplicated by bleeding (about 10 mL/time, once every other day, for 5 times) and food restriction (half of the normal quantity). Bilateral "Zusanli" (ST 36) were punctured by using filiform needles. The needles were not lifted and thrust for rabbits of the needle-retaining group, but lifted and thrust for 15 min for rabbits of the reinforcing and reducing groups. The treatment was given once every other day, 10 times altogether. Serum SF and TIBC levels were assayed by radioimmunoassay. Results Following modeling, compared to the blank control group, serum SF content was decreased significantly (P0. 05). Conclusion Both reinforcing and reducing manipulation of acupuncture of "2usanli"(ST 36) can up-regulate serum SF content and down-regulate TIBC level in blood-deficiency syndrome rabbits, which may contribute to their effects in improving blood-deficiency syndrome and has no significant difference.%目的:通过观察针刺提插补泻“足三里”穴对血虚证家兔血清铁蛋白(SF)和总铁结合力(TIBC)的影响,探讨提插补泻与效应的关系.方法:将60只家兔随机分为5组:空白组、模型组、留针组、补法组、泻法组,每组12只.采用放血加限食法制造血虚证模型.针刺各组每次治疗15 min,隔天治疗1次,共计10次.采用放射免疫法检测血清SF及TIBC.结果:针刺治疗后第17天,补法、泻法两组的SF与针刺前相比明显升高(P<0.05),TIBC明显降低(P<0.05);针刺治疗后第32天,

  3. Iron and Ferritin Levels in Saliva of Patients with Thalassemia and Iron Deficiency Anemia

    OpenAIRE

    Canatan, Duran; Akdeniz, Sevgi Kosaci

    2012-01-01

    Most of the techniques for measuring iron stores such as serum iron concentration, iron binding capacity, serum ferritin level, liver biopsy can be troublesome or invasive for patients with thalassemia. The salivary iron measurement could be of potential advantage being an easy and non invasive approach for diagnosis of iron deficiency and iron overload . The aim of this study was to compare the levels of iron and ferritin in saliva and serum of patients affected by thalassemia or iron defici...

  4. Mechanism of ferrous iron binding and oxidation by ferritin from a pennate diatom.

    Science.gov (United States)

    Pfaffen, Stephanie; Abdulqadir, Raz; Le Brun, Nick E; Murphy, Michael E P

    2013-05-24

    A novel ferritin was recently found in Pseudo-nitzschia multiseries (PmFTN), a marine pennate diatom that plays a major role in global primary production and carbon sequestration into the deep ocean. Crystals of recombinant PmFTN were soaked in iron and zinc solutions, and the structures were solved to 1.65-2.2-Å resolution. Three distinct iron binding sites were identified as determined from anomalous dispersion data from aerobically grown ferrous soaked crystals. Sites A and B comprise the conserved ferroxidase active site, and site C forms a pathway leading toward the central cavity where iron storage occurs. In contrast, crystal structures derived from anaerobically grown and ferrous soaked crystals revealed only one ferrous iron in the active site occupying site A. In the presence of dioxygen, zinc is observed bound to all three sites. Iron oxidation experiments using stopped-flow absorbance spectroscopy revealed an extremely rapid phase corresponding to Fe(II) oxidation at the ferroxidase site, which is saturated after adding 48 ferrous iron to apo-PmFTN (two ferrous iron per subunit), and a much slower phase due to iron core formation. These results suggest an ordered stepwise binding of ferrous iron and dioxygen to the ferroxidase site in preparation for catalysis and a partial mobilization of iron from the site following oxidation.

  5. The Relationship between Albumin-Binding Capacity of Recombinant Polypeptide and Changes in the Structure of Albumin-Binding Domain.

    Science.gov (United States)

    Bormotova, E A; Gupalova, T V

    2015-07-01

    Many bacteria express surface proteins interacting with human serum albumin (HSA). One of these proteins, PAB from anaerobic bacteria, contains an albumin-binding domain consisting of 45 amino acid residues known as GA domain. GA domains are also found in G proteins isolated from human streptococcal strains (groups C and G) and of albumin-binding protein isolated from group G streptococcal strains of animal origin. The GA domain is a left-handed three-helix bundle structure in which amino acid residues of the second and third helixes are involved in albumin binding. We studied the relationship between HSA-binding activity of the recombinant polypeptide isolated from group G streptococcus of animal origin and structure of the GA domain is studied. Structural changes in GA domain significantly attenuated HAS-binding capacity of the recombinant polypeptide. Hence, affinity HSA-binding polypeptide depends on stability of GA domain structure.

  6. The Mycobacterium tuberculosis high-affinity iron importer, IrtA, contains an FAD-binding domain.

    Science.gov (United States)

    Ryndak, Michelle B; Wang, Shuishu; Smith, Issar; Rodriguez, G Marcela

    2010-02-01

    Iron is an essential nutrient not freely available to microorganisms infecting mammals. To overcome iron deficiency, bacteria have evolved various strategies including the synthesis and secretion of high-affinity iron chelators known as siderophores. The siderophores produced and secreted by Mycobacterium tuberculosis, exomycobactins, compete for iron with host iron-binding proteins and, together with the iron-regulated ABC transporter IrtAB, are required for the survival of M. tuberculosis in iron deficient conditions and for normal replication in macrophages and in mice. This study further characterizes the role of IrtAB in M. tuberculosis iron acquisition. Our results demonstrate a role for IrtAB in iron import and show that the amino terminus domain of IrtA is a flavin-adenine dinucleotide-binding domain essential for iron acquisition. These results suggest a model in which the amino terminus of IrtA functions to couple iron transport and assimilation.

  7. In Vitro Bile Acid Binding Capacities of Red Leaf Lettuce and Cruciferous Vegetables.

    Science.gov (United States)

    Yang, Isabelle F; Jayaprakasha, Guddadarangavvanahally K; Patil, Bhimanagouda S

    2017-09-13

    In the present study, we tested the bile acid binding capacity of red leaf lettuce, red cabbage, red kale, green kale, and Brussels sprouts through in vitro digestion process by simulating mouth, gastric, and intestinal digestion using six bile acids at physiological pH. Green and red kale exhibited significantly higher (86.5 ± 2.9 and 89.7 ± 0.9%, respectively) bile acid binding capacity compared to the other samples. Further, three different compositions of bile acids were tested to understand the effect on different health conditions. To predict the optimal dose for bile acid binding, we established a logistic relationship between kale dose and bile acid binding capacity. The results indicated that kale showed significantly higher bile acid binding capacity (82.5 ± 2.9% equivalent to 72.06 mg) at 1.5 g sample and remained constant up to 2.5 g. In addition, minimally processed (microwaved 3 min or steamed 8 min) green kale showed significantly enhanced bile acid binding capacity (91.1 ± 0.3 and 90.2 ± 0.7%, respectively) compared to lyophilized kale (85.5 ± 0.24%). Among the six bile acids tested, kale preferentially bound hydrophobic bile acids chenodeoxycholic acid and deoxycholic acid. Therefore, regular consumption of kale, especially minimally processed kale, can help excrete more bile acids and, thus, may lower the risk of hypercholesterolemia.

  8. A computational study of ligand binding affinities in iron(III) porphine and protoporphyrin IX complexes.

    Science.gov (United States)

    Durrant, Marcus C

    2014-07-01

    The search for novel anti-malarial drugs that can disrupt biomineralization of ferriprotoporphyrin IX to haemozoin requires an understanding of the fundamental chemistry of the porphyrin's iron(iii) centre at the water-lipid interface. Towards this end, the binding affinities for a diverse set of 31 small ligands with iron(iii) porphine have been calculated using density functional theory, in the gas phase and also with implicit solvent corrections for both water and n-octanol. In addition, the binding of hydroxide, chloride, acetate, methylamine and water to ferriprotoporphyrin IX has been studied, and very similar trends are observed for the smaller and larger models. Anionic ligands generally give stronger binding than neutral ones; the strongest binding is observed for RO(-) and OH(-) ligands, whilst acetate binds relatively weakly among the anions studied. Electron-rich nitrogen donors tend to bind more strongly than electron-deficient ones, and the weakest binding is found for neutral O and S donors such as oxazole and thiophene. In all cases, ligand binding is stronger in n-octanol than in water, and the differences in binding energies for the two solvents are greater for ionic ligands than for neutrals. Finally, dimerization of ferriprotoporphyrin IX by means of iron(iii)-carboxylate bond formation has been modelled. The results are discussed in terms of haemozoin crystal growth and its disruption by known anti-malarial drugs.

  9. Carboxymethyl cellulose coating decreases toxicity and oxidizing capacity of nanoscale zerovalent iron.

    Science.gov (United States)

    Zhou, Lei; Thanh, Thao Le; Gong, Jianyu; Kim, Jae-Hwan; Kim, Eun-Ju; Chang, Yoon-Seok

    2014-06-01

    Nanoscale zerovalent iron (NZVI) with modified surface via coating with organic stabilizers has been documented with enhanced colloidal stability and dispersity. Therefore, the expanded application potential and accompanying intrinsic exposure of such nanoparticle can be anticipated. In our study, carboxymethyl cellulose (CMC)-stabilized NZVI (CNZVI) exerted minimized oxidative stress response and slower disruption of cell membrane integrity, resulting in mitigated cytotoxicity towards bacteria Agrobacterium sp. PH-08 as compared with the uncoated counterpart. The corrosive oxidation of both nanoparticles in oxygenic water provided a better understanding of coating effect. The decreased oxidative degradation of probe 4-chlorophenol with CNZVI than NZVI implicated a weaker oxidizing capacity, which might overweight massive adhesion-mediated redox damage and explain the different exposure outcome. However, enhanced evolution of iron oxide as well as the promoted production of hydrogen peroxide adversely demonstrated CMC-coating facilitated iron corrosion by oxygen, suggesting CMC was most likely to act as a radical scavenger and compete with organics or bacteria for oxidants. Moreover, XRD, XPS and TEM results showed that the spherical NZVI was oxidized to form needle-shaped iron oxide-hydroxide (γFeOOH) with no detectable oxidative stress for PH-08, alleviating worries regarding exotoxicological impact of iron nanotechnology.

  10. Binding of serum ferritin to concanavalin A in patients with iron overload and with chronic liver disease.

    OpenAIRE

    Chapman, R. W.; Gorman, A; Laulicht, M; Hussain, M A; Sherlock, S; Hoffbrand, A V

    1982-01-01

    Total serum ferritin and the proportion of serum ferritin binding to concanavalin A (glycosylated ferritin) was measured in 18 healthy volunteers and in 84 patients, eight with primary haemochromatosis, 43 with beta-thalassaemia major and secondary iron overload and 33 with chronic liver diseases without iron overload. The total serum ferritin was either equally or even more closely related than either the non-binding or the concanavalin A binding ferritin, to the liver iron concentration in ...

  11. Formation of crystalline nanoparticles by iron binding to pentapeptide (Asp-His-Thr-Lys-Glu) from egg white hydrolysates.

    Science.gov (United States)

    Sun, Na; Cui, Pengbo; Li, Dongmei; Jin, Ziqi; Zhang, Shuyu; Lin, Songyi

    2017-09-20

    A novel peptide from egg white, Asp-His-Thr-Lys-Glu (DHTKE), contains specific amino acids associated with iron binding. The present study aims to better understand the molecular basis of interactions between the DHTKE peptide and iron ions. The ultraviolet-visible and fluorescence spectra indicate an interaction between the DHTKE peptide and iron ions, which leads to the formation of a DHTKE-iron complex. Notably, Asp, Glu, His, and Lys in the DHTKE peptide play crucial roles in the formation of the DHTKE-iron complex, and the iron-binding site of the DHTKE peptide corresponds primarily to the amide and carboxyl groups. The DHTKE peptide can bind iron ions in a 1 : 2 ratio with a binding constant of 1.312 × 10(5) M(-1). Moreover, the DHTKE-iron complex belongs to thermodynamically stable nanoparticles that are present in the crystalline structure, which might be attributed to peptide folding induced by iron binding. Meanwhile, the DHTKE-iron complex exhibits a relatively high iron-releasing percentage and exerts excellent solubility in the human gastrointestinal tract in vitro. This suggests a potential application of peptides containing Asp, Glu, His, or Lys residues as potential iron supplements.

  12. Effect of peripheral trifluoromethyl groups in artificial iron porphycene cofactor on ligand binding properties of myoglobin.

    Science.gov (United States)

    Matsuo, Takashi; Ito, Kazuyuki; Nakashima, Yuji; Hisaeda, Yoshio; Hayashi, Takashi

    2008-02-01

    An iron porphycene, a structural isomer of iron porphyrin, with trifluoromethyl groups at the peripheral position of the framework was incorporated into sperm whale apomyoglobin. The prepared myoglobin shows the higher O(2) affinity than the native protein. However, the oxygen affinity of the reconstituted myoglobin is lower than that of the myoglobin having an iron porphycene without trifluoromethyl groups, which is mainly originated from the enhancement of the O(2) dissociation. The CO affinity of the myoglobin with the trifluoromethylated iron porphycene is similar to that observed for the reference protein having the iron porphycene without trifluoromethyl groups, although their C-O stretching frequencies are significantly different. The relationship between the electronic states of the porphycene ring and the ligand bindings is discussed.

  13. Iron deficiency.

    Science.gov (United States)

    Scrimshaw, N S

    1991-10-01

    The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world.

  14. Effects of Iron Supplementation and Activity on Serum Iron Depletion and Hemoglobin Levels in Female Athletes

    Science.gov (United States)

    Cooter, G. Rankin; Mowbray, Kathy W.

    1978-01-01

    Research revealed that a four-month basketball training program did not significantly alter serum iron, total iron binding capacity, hemoglobin, and percent saturation levels in female basketball athletes. (JD)

  15. Influence of binding pH and protein solubility on the dynamic binding capacity in hydrophobic interaction chromatography.

    Science.gov (United States)

    Baumann, Pascal; Baumgartner, Kai; Hubbuch, Jürgen

    2015-05-29

    Hydrophobic interaction chromatography (HIC) is one of the most frequently used purification methods in biopharmaceutical industry. A major drawback of HIC, however, is the rather low dynamic binding capacity (DBC) obtained when compared to e.g. ion exchange chromatography (IEX). The typical purification procedure for HIC includes binding at neutral pH, independently of the proteins nature and isoelectric point. Most approaches to process intensification are based on resin and salt screenings. In this paper a combination of protein solubility data and varying binding pH leads to a clear enhancement of dynamic binding capacity. This is shown for three proteins of acidic, neutral, and alkaline isoelectric points. High-throughput solubility screenings as well as miniaturized and parallelized breakthrough curves on Media Scout RoboColumns (Atoll, Germany) were conducted at pH 3-10 on a fully automated robotic workstation. The screening results show a correlation between the DBC and the operational pH, the protein's isoelectric point and the overall solubility. Also, an inverse relationship of DBC in HIC and the binding kinetics was observed. By changing the operational pH, the DBC could be increased up to 30% compared to the standard purification procedure performed at neutral pH. As structural changes of the protein are reported during HIC processes, the applied samples and the elution fractions were proven not to be irreversibly unfolded. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Effect of iron overload on exercise capacity in thalassemic patients with heart failure.

    Science.gov (United States)

    Mavrogeni, Sophie; Gotsis, Efstathios; Verganelakis, Dimitrios; Berdousis, Eleni; Dritsas, Athanasios; Kolovou, Genovefa; Toulas, Panagiotis; Ladis, Vassilios

    2009-12-01

    In b-thalassemia, myocardial iron overload contributes to heart failure, despite chelation treatment. We hypothesized that myocardial T2*, an index of iron overload, influences patients' physical activity. We assessed a thalassemic population by both cardiovascular magnetic resonance imaging (CMR) and ergospirometry test. Sixty-six thalassemic patients aged 27 (19-40) years, 30 without (NHF) and 36 with heart failure (HF), were studied. Cardiac T2* and left ventricular ejection fraction (LVEF) were evaluated using a 1.5 T system. VO(2max), AT, Mets and duration of exercise by ergospirometry were also assessed. Myocardial T2* was lower in HF compared to NHF patients (14.7 +/- 6.6 vs. 39 +/- 2 ms, P iron overloaded (HF-H) and the rest of them (n = 23) as (HF-L). Although LVEDV, LVESV, LVEF were similar in the two subgroups, the exercise parameters were significantly lower in the HF-H group (P Heart T2* correlated with all exercise parameters (P iron overload, expressed as T2*, has a direct influence on exercise capacity, independent of LV ejection fraction and functional class.

  17. Ionic residues of human serum transferrin affect binding to the transferrin receptor and iron release.

    Science.gov (United States)

    Steere, Ashley N; Miller, Brendan F; Roberts, Samantha E; Byrne, Shaina L; Chasteen, N Dennis; Smith, Valerie C; MacGillivray, Ross T A; Mason, Anne B

    2012-01-17

    Efficient delivery of iron is critically dependent on the binding of diferric human serum transferrin (hTF) to its specific receptor (TFR) on the surface of actively dividing cells. Internalization of the complex into an endosome precedes iron removal. The return of hTF to the blood to continue the iron delivery cycle relies on the maintenance of the interaction between apohTF and the TFR after exposure to endosomal pH (≤6.0). Identification of the specific residues accounting for the pH-sensitive nanomolar affinity with which hTF binds to TFR throughout the cycle is important to fully understand the iron delivery process. Alanine substitution of 11 charged hTF residues identified by available structures and modeling studies allowed evaluation of the role of each in (1) binding of hTF to the TFR and (2) TFR-mediated iron release. Six hTF mutants (R50A, R352A, D356A, E357A, E367A, and K511A) competed poorly with biotinylated diferric hTF for binding to TFR. In particular, we show that Asp356 in the C-lobe of hTF is essential to the formation of a stable hTF-TFR complex: mutation of Asp356 in the monoferric C-lobe hTF background prevented the formation of the stoichiometric 2:2 (hTF:TFR monomer) complex. Moreover, mutation of three residues (Asp356, Glu367, and Lys511), whether in the diferric or monoferric C-lobe hTF, significantly affected iron release when in complex with the TFR. Thus, mutagenesis of charged hTF residues has allowed identification of a number of residues that are critical to formation of and release of iron from the hTF-TFR complex.

  18. Circulating Retinol-Binding Protein-4 Concentration Might Reflect Insulin Resistance–Associated Iron Overload

    Science.gov (United States)

    Fernández-Real, José Manuel; Moreno, José María; Ricart, Wifredo

    2008-01-01

    OBJECTIVES—The mechanisms behind the association between retinol-binding protein-4 (RBP4) and insulin resistance are not well understood. An interaction between iron and vitamin A status, of which RBP4 is a surrogate, has long been recognized. We hypothesized that iron-associated insulin resistance could be behind the impaired insulin action caused by RBP4. RESEARCH DESIGN AND METHODS—Serum ferritin and RBP4 concentration and insulin resistance were evaluated in a sample of middle-aged men (n = 132) and in a replication independent study. Serum RBP4 was also studied before and after iron depletion in patients with type 2 diabetes. Finally, the effect of iron on RBP4 release was evaluated in vitro in adipose tissue. RESULTS—A positive correlation between circulating RBP4 and log serum ferritin (r = 0.35 and r = 0.61, respectively; P diabetic patients (percent mean difference −13.7 [95% CI −25.4 to −2.04]; P = 0.024). The iron donor lactoferrin led to increased dose-dependent adipose tissue release of RBP4 (2.4-fold, P = 0.005) and increased RBP4 expression, while apotransferrin and deferoxamine led to decreased RBP4 release. CONCLUSIONS—The relationship between circulating RBP4 and iron stores, both cross-sectional and after iron depletion, and in vitro findings suggest that iron could play a role in the RBP4–insulin resistance relationship. PMID:18426863

  19. The coproporphyrin ferrochelatase of Staphylococcus aureus : mechanistic insights into a regulatory iron binding site.

    Science.gov (United States)

    Hobbs, Charlie; Reid, J D; Shepherd, Mark

    2017-09-01

    The majority of characterised ferrochelatase enzymes catalyse the final step of classical haem synthesis, inserting ferrous iron into protoporphyrin IX. However, for the recently-discovered coproporphyrin-dependent pathway, ferrochelatase catalyses the penultimate reaction where ferrous iron is inserted into coproporphyrin III. Ferrochelatase enzymes from the bacterial phyla Firmicutes and Actinobacteria have previously been shown to insert iron into coproporphyrin, and those from Bacillus subtilis and Staphylococcus aureus are known to be inhibited by elevated iron concentrations. The work herein reports a Km (coproporphyrin III) for S. aureus ferrochelatase of 1.5 µM and it is shown that elevating the iron concentration increases the Km for coproporphyrin III, providing a potential explanation for the observed iron-mediated substrate inhibition. Together, structural modelling, site-directed mutagenesis, and kinetic analyses confirm residue Glu271 as being essential for the binding of iron to the inhibitory regulatory site on S. aureus ferrochelatase, providing a molecular explanation for the observed substrate inhibition patterns. This work therefore has implications for how haem biosynthesis in S. aureus is regulated by iron availability. ©2017 The Author(s).

  20. Decreased angiotensin II binding affinity and binding capacity in the anterior pituitary gland of adult spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Gutkind, J.S.; Castren, E.; Saavedra, J.M.

    1988-01-01

    Angiotensin II (ANG) binding sites were quantified in single pituitary glands from 4-week-old and 14-week-old male spontaneously hypertensive rats (SHR) and age-matched male normotensive Wistar-Kyoto (WKY) control rats after incubation with /sup 125/I-(Sar/sup 1/)-ANG, autoradiography with computerized densitometry, and comparison to /sup 125/I-standards. The maximum binding capacity (B/sub max/) decreased while the dissociation constant (K/sub d/) for ANG increased in 14-week-old SHR when compared to age-matched WKY control rats. Conversely, no difference between rat strains was found in 4-week-old animals. Our results suggest that pituitary ANG binding sites may play a role in the pathophysiology of established genetic hypertension.

  1. Distinct Iron-binding Ligands in the Upper Water Column at Station ALOHA

    Science.gov (United States)

    Bundy, R.; Boiteau, R.; Repeta, D.

    2016-02-01

    The distribution and chemical properties of iron-binding organic ligands at station ALOHA were examined using a combination of solid phase extraction (SPE) followed by high pressure liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS). HPLC-ICPMS ligand measurements were complemented by competitive ligand exchange adsorptive cathodic stripping voltammetry (CLE-ACSV) analysis using salicylaldoxime as the added ligand. By HPLC-ICPMS, we find enhanced concentrations of distinct naturally-occurring polar iron-binding ligands present at the surface and in the chlorophyll maximum. Lower concentrations were found in the subsurface, where a suite of non-polar ligands was detected. Siderophores were present at the deepest depths sampled at station ALOHA, down to 400m. Incubation studies provided evidence for the production of iron-binding ligands associated with nutrient amended phytoplankton growth in surface waters, and as a result of microbial particle remineralization in the subsurface water column. Ligands classes identified via SPE were then compared to CLE-ACSV ligand measurements, as well as the conditional stability constants measured from model polar and non-polar siderophores, yielding insight to the sources of iron-binding ligands throughout the water column at station ALOHA.

  2. Analysis of novel iron-regulated, surface-anchored hemin-binding proteins in Corynebacterium diphtheriae.

    Science.gov (United States)

    Allen, Courtni E; Burgos, Jonathan M; Schmitt, Michael P

    2013-06-01

    Corynebacterium diphtheriae utilizes hemin and hemoglobin (Hb) as iron sources during growth in iron-depleted environments, and recent studies have shown that the surface-exposed HtaA protein binds both hemin and Hb and also contributes to the utilization of hemin iron. Conserved (CR) domains within HtaA and in the associated hemin-binding protein, HtaB, are required for the ability to bind hemin and Hb. In this study, we identified and characterized two novel genetic loci in C. diphtheriae that encode factors that bind hemin and Hb. Both genetic systems contain two-gene operons that are transcriptionally regulated by DtxR and iron. The gene products of these operons are ChtA-ChtB and ChtC-CirA (previously DIP0522-DIP0523). The chtA and chtB genes are carried on a putative composite transposon associated with C. diphtheriae isolates that dominated the diphtheria outbreak in the former Soviet Union in the 1990s. ChtA and ChtC each contain a single N-terminal CR domain and exhibit significant sequence similarity to each other but only limited similarity with HtaA. The chtB and htaB gene products exhibited a high level of sequence similarity throughout their sequences, and both proteins contain a single CR domain. Whole-cell binding studies as well as protease analysis indicated that all four of the proteins encoded by these two operons are surface exposed, which is consistent with the presence of a transmembrane segment in their C-terminal regions. ChtA, ChtB, and ChtC are able to bind hemin and Hb, with ChtA showing the highest affinity. Site-directed mutagenesis showed that specific tyrosine residues within the ChtA CR domain were critical for hemin and Hb binding. Hemin iron utilization assays using various C. diphtheriae mutants indicate that deletion of the chtA-chtB region and the chtC gene has no affect on the ability of C. diphtheriae to use hemin or Hb as iron sources; however, a chtB htaB double mutant exhibits a significant decrease in hemin iron use

  3. Iron-Binding Protein Degradation by Cysteine Proteases of Naegleria fowleri.

    Science.gov (United States)

    Martínez-Castillo, Moisés; Ramírez-Rico, Gerardo; Serrano-Luna, Jesús; Shibayama, Mineko

    2015-01-01

    Naegleria fowleri causes acute and fulminant primary amoebic meningoencephalitis. This microorganism invades its host by penetrating the olfactory mucosa and then traveling up the mesaxonal spaces and crossing the cribriform plate; finally, the trophozoites invade the olfactory bulbs. During its invasion, the protozoan obtains nutrients such as proteins, lipids, carbohydrates, and cationic ions (e.g., iron, calcium, and sodium) from the host. However, the mechanism by which these ions are obtained, particularly iron, is poorly understood. In the present study, we evaluated the ability of N. fowleri to degrade iron-binding proteins, including hololactoferrin, transferrin, ferritin, and hemoglobin. Zymography assays were performed for each substrate under physiological conditions (pH 7 at 37°C) employing conditioned medium (CM) and total crude extracts (TCEs) of N. fowleri. Different degradation patterns with CM were observed for hololactoferrin, transferrin, and hemoglobin; however, CM did not cause ferritin degradation. In contrast, the TCEs degraded only hololactoferrin and transferrin. Inhibition assays revealed that cysteine proteases were involved in this process. Based on these results, we suggest that CM and TCEs of N. fowleri degrade iron-binding proteins by employing cysteine proteases, which enables the parasite to obtain iron to survive while invading the central nervous system.

  4. Iron-Binding Protein Degradation by Cysteine Proteases of Naegleria fowleri

    Directory of Open Access Journals (Sweden)

    Moisés Martínez-Castillo

    2015-01-01

    Full Text Available Naegleria fowleri causes acute and fulminant primary amoebic meningoencephalitis. This microorganism invades its host by penetrating the olfactory mucosa and then traveling up the mesaxonal spaces and crossing the cribriform plate; finally, the trophozoites invade the olfactory bulbs. During its invasion, the protozoan obtains nutrients such as proteins, lipids, carbohydrates, and cationic ions (e.g., iron, calcium, and sodium from the host. However, the mechanism by which these ions are obtained, particularly iron, is poorly understood. In the present study, we evaluated the ability of N. fowleri to degrade iron-binding proteins, including hololactoferrin, transferrin, ferritin, and hemoglobin. Zymography assays were performed for each substrate under physiological conditions (pH 7 at 37°C employing conditioned medium (CM and total crude extracts (TCEs of N. fowleri. Different degradation patterns with CM were observed for hololactoferrin, transferrin, and hemoglobin; however, CM did not cause ferritin degradation. In contrast, the TCEs degraded only hololactoferrin and transferrin. Inhibition assays revealed that cysteine proteases were involved in this process. Based on these results, we suggest that CM and TCEs of N. fowleri degrade iron-binding proteins by employing cysteine proteases, which enables the parasite to obtain iron to survive while invading the central nervous system.

  5. An Iron-Binding Protein, Dpr, from Streptococcus mutans Prevents Iron-Dependent Hydroxyl Radical Formation In Vitro

    OpenAIRE

    Yamamoto, Yuji; Poole, Leslie B.; Hantgan, Roy R.; Kamio, Yoshiyuki

    2002-01-01

    The dpr gene is an antioxidant gene which was isolated from the Streptococcus mutans chromosome by its ability to complement an alkyl hydroperoxide reductase-deficient mutant of Escherichia coli, and it was proven to play an indispensable role in oxygen tolerance in S. mutans. Here, we purified the 20-kDa dpr gene product, Dpr, from a crude extract of S. mutans as an iron-binding protein and found that Dpr formed a spherical oligomer about 9 nm in diameter. Molecular weight determinations of ...

  6. Isolation of an iron-binding protein from the hemolymph of the horseshoe crab (Limulus polyhemus)

    Energy Technology Data Exchange (ETDEWEB)

    Topham, R.; Cooper, B.; Tesh, S.; Bonaventura, C.

    1987-05-01

    The presence of an iron-binding protein in the hemolymph of Limulus was detected by gel-filtration of /sup 59/Fe-labeled hemolymph. This protein was easily separated from hemocyanin, the oxygen transport protein that constitutes greater than 90% of the protein of Limulus hemolymph. The amount of the Limulus iron-binding protein (LIBP) in hemolymph samples prepared under sterile and non-sterile conditions was identical. LIBP was purified to homogeneity by ion-exchange chromatography. The molecular weight of purified LIBP was estimated by gel-filtration to be 282,000 + 10,000. SDS-electrophoresis demonstrated that LIBP was an oligomeric protein composed of subunits with a molecular weight of 28,000 +/- 2000. The isoelectric point of LIBP was 6.5 as determined by electrofocusing. No /sup 49/Fe was removed from purified LIBP by extensive dialysis with EDTA or 2,2'-dipyridyl. Purified, unlabeled LIBP efficiently sequestered /sup 59/Fe in the absence of hemolymph indicating that no other hemolymph factors are required for the incorporation of iron into LIBP. The isolation of LIBP would support the proposal that the development of specific iron-binding and transport proteins was not necessarily coupled to the development of hemoglobin as a means to accomplish oxygen transport.

  7. Ca sup 2+ binding capacity of cytoplasmic proteins from rod photoreceptors is mainly due to arrestin

    Energy Technology Data Exchange (ETDEWEB)

    Huppertz, B.; Weyand, I.; Bauer, P.J. (Institut fuer Biologische Informationsverarbeitung, Forschungszentrum Juelich GmbH (Germany, F.R.))

    1990-06-05

    Arrestin (also called S-antigen or 48-kDa protein) binds to photoexcited and phosphorylated rhodopsin and, thereby, blocks competitively the activation of transducin. Using Ca{sup 2+} titration in the presence of the indicator arsenazo III and {sup 45}Ca{sup 2+} autoradiography, we show that arrestin is a Ca2(+)-binding protein. The Ca{sup 2+} binding capacity of arresting-containing protein extracts from bovine rod outer segments is about twice as high as that of arrestin-depleted extracts. The difference in the Ca{sup 2+} binding of arrestin-containing and arrestin-depleted protein extracts was attributed to arrestin. Both, these difference-measurements of protein extracts and the measurements of purified arrestin yield dissociation constants for the Ca{sup 2+} binding of arrestin between 2 and 4 microM. The titration curves are consistent with a molar ratio of one Ca{sup 2+} binding site per arrestin. No Ca{sup 2+} binding in the micromolar range was found in extracts containing mainly transducin and cGMP-phosphodiesterase. Since arrestin is one of the most abundant proteins in rod photoreceptors occurring presumably up to millimolar concentrations in rod outer segments, we suggest that aside from its function to prevent the activation of transducin, arrestin acts probably as an intracellular Ca{sup 2+} buffer.

  8. Utilization of host iron sources by Corynebacterium diphtheriae: multiple hemoglobin-binding proteins are essential for the use of iron from the hemoglobin-haptoglobin complex.

    Science.gov (United States)

    Allen, Courtni E; Schmitt, Michael P

    2015-02-01

    The use of hemin iron by Corynebacterium diphtheriae requires the DtxR- and iron-regulated ABC hemin transporter HmuTUV and the secreted Hb-binding protein HtaA. We recently described two surface anchored proteins, ChtA and ChtC, which also bind hemin and Hb. ChtA and ChtC share structural similarities to HtaA; however, a function for ChtA and ChtC was not determined. In this study, we identified additional host iron sources that are utilized by C. diphtheriae. We show that several C. diphtheriae strains use the hemoglobin-haptoglobin (Hb-Hp) complex as an iron source. We report that an htaA deletion mutant of C. diphtheriae strain 1737 is unable to use the Hb-Hp complex as an iron source, and we further demonstrate that a chtA-chtC double mutant is also unable to use Hb-Hp iron. Single-deletion mutants of chtA or chtC use Hb-Hp iron in a manner similar to that of the wild type. These findings suggest that both HtaA and either ChtA or ChtC are essential for the use of Hb-Hp iron. Enzyme-linked immunosorbent assay (ELISA) studies show that HtaA binds the Hb-Hp complex, and the substitution of a conserved tyrosine (Y361) for alanine in HtaA results in significantly reduced binding. C. diphtheriae was also able to use human serum albumin (HSA) and myoglobin (Mb) but not hemopexin as iron sources. These studies identify a biological function for the ChtA and ChtC proteins and demonstrate that the use of the Hb-Hp complex as an iron source by C. diphtheriae requires multiple iron-regulated surface components.

  9. Binding of zinc and iron to wheat bread, wheat bran, and their components.

    Science.gov (United States)

    Ismail-Beigi, F; Faraji, B; Reinhold, J G

    1977-10-01

    Wholemeal wheat bread decreases the availability and intestinal absorption of divalent metals. To define this action further, binding of zinc in vitro to a wheat wholemeal bread (Tanok), dephytinized Tanok, and cellulose was determined at pH 5.0 to 7.5. Zinc binding by each was highly pH-dependent and reached a maximum at pH 6.5 to 7.5. Removal of phytate from Tanok did not reduce its binding capability. Wheat bran at pH 6.5 and 6.8 bound 72% of iron (0.5 microgram/ml of solution) and 82.5% of zinc (1.43 microgram/ml solution), respectively. Lignin and two of the hemicellulose fractions of wheat bran and high binding capabilities for zinc (85.6, 87.1, and 82.1%, respectively) whereas a third had a lower zinc-binding capability (38.7%). Binding of zinc to various celluloses and dextrans is also demonstrated. Formation of complexes of these metals with wheat fiber can explain, at least in part, the decreased availability of dietary iron and zinc in wholemeal wheat bread.

  10. Interrelationship between Manganese and Iron for Binding to Apo-Transferrin

    Directory of Open Access Journals (Sweden)

    T. Hassanzadeh Ghasabeh

    2003-07-01

    Full Text Available Manganese is an essential trace elenent. There is a little evidence for deficiency of manganese in human , while as its toxicity has been reported in several cases. Manganese toxicity occurrs in humans exposed to high enviromental concentrations (for example workers in the dry battery production and may be particularly important in the neonatal period. The chemical similarities between manganese and iron and their binding to apo-transferrin (apo-tf may lead to the disturbances of iron metabolism. In the present project the interrelationship of anemia and manganese toxicity by techniques such as Affinity chromatography ; Equilibrium dialysis ; Urea polyacrylamide gel electrophoresis ; Spectrophotometric titration was investigated. The charactristics of Mn and Fe binding to apo-tf have been investigated and compared in this article . Using Equilibrium dialysis technique the binding of Fe and Mn to apo-tf was also studied. The binding constant of Mn to apo-tf was calculated using scatchared plot analysis. Addition of Mn (1.5 g/ml to reaction mixture containing Fe and apo-tf reduced Fe binding to apo-transferrin in comparison to control. Using Urea polyacrylamide gel electrophoresis (Urea-PAGE technique conforming the binding of Mn to apo-tf. The data that has been presented in this article elucidated the probable mechanism by which Mn interference with Fe metabolism; which result in the apperance of anemia.

  11. Iron uptake and increased intracellular enzyme activity follow host lactoferrin binding by Trichomonas vaginalis receptors

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, K.M.; Alderete, J.F.

    1984-08-01

    Lactoferrin acquisition and iron uptake by pathogenic Trichomonas vaginalis was examined. Saturation binding kinetics were obtained for trichomonads using increasing amounts of radioiodinated lactoferrin, while no significant binding by transferrin under similar conditions was achieved. Only unlabeled lactoferrin successfully and stoichiometrically competed with 125I-labeled lactoferrin binding. Time course studies showed maximal lactoferrin binding by 30 min at 37 degrees C. Data suggest no internalization of bound lactoferrin. The accumulation of radioactivity in supernatants after incubation of T. vaginalis with 125I-labeled lactoferrin and washing in PBS suggested the presence of low affinity sites for this host macromolecule. Scatchard analysis indicated the presence of 90,000 receptors per trichomonad with an apparent Kd of 1.0 microM. Two trichomonad lactoferrin binding proteins were identified by affinity chromatography and immunoprecipitation of receptor-ligand complexes. A 30-fold accumulation of iron was achieved using 59Fe-lactoferrin when compared to the steady state concentration of bound lactoferrin. The activity of pyruvate/ferrodoxin oxidoreductase, an enzyme involved in trichomonal energy metabolism, increased more than sixfold following exposure of the parasites to lactoferrin, demonstrating a biologic response to the receptor-mediated binding of lactoferrin. These data suggest that T. vaginalis possesses specific receptors for biologically relevant host proteins and that these receptors contribute to the metabolic processes of the parasites.

  12. Iron titanium phosphates as high-specific-capacity electrode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Essehli, R., E-mail: essehli.rachid@yahoo.fr [Laboratory of Mineral Solid and Analytical Chemistry (LMSAC), Department of Chemistry, Faculty of Sciences, University Mohamed I, PO. Box 717, 60000 Oujda (Morocco); ESECO SYSTEMS 270 rue Thomas Edison, Atelier Relais No 6, 34400 Lunel (France); El Bali, B. [Laboratory of Mineral Solid and Analytical Chemistry (LMSAC), Department of Chemistry, Faculty of Sciences, University Mohamed I, PO. Box 717, 60000 Oujda (Morocco); Faik, A. [CIC energigune, Parque Tecnológico de Álava, Albert Einstein 48, 01510 Miñano, Álava (Spain); Naji, M. [CNRS, UPR3079 CEMHTI, 1D avenue de la Recherche Scientifique, 45071 Orléans cedex 2 (France); Benmokhtar, S. [LCPGM, Laboratoire de Chimie-Physique Générale des Matériaux, Département de Chimie, Université Hassan II-Mohammedia, Faculté des Sciences Ben M’Sik, Casablanca (Morocco); Zhong, Y.R.; Su, L.W.; Zhou, Z. [Institute of New Energy Material Chemistry, Synergetic Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071 (China); Kim, J.; Kang, K. [Department of Materials Science and Engineering, Seoul National University, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Dusek, M. [Institute of Physics of the ASCR, v.v.i., Na Slovance 2, 182 21 Praha 8 (Czech Republic)

    2014-02-05

    Highlights: • Iron Titanium Phosphates as High-Specific-Capacity. • Electrode Materials for Lithium ion Batteries. • During the following cycles, good reversible capacity retention and better cyclabilit. • Ex-situ XRD analysis during the first discharge shows an amorphization of this anode material. -- Abstract: Two iron titanium phosphates, Fe{sub 0.5}TiOPO{sub 4} and Fe{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3}, were prepared, and their crystal structures and electrochemical performances were compared. The electrochemical measurements of Fe{sub 0.5}TiOPO{sub 4} as an anode of a lithium ion cell showed that upon the first discharge down to 0.5 V, the cell delivered a capacity of 560 mA h/g, corresponding to the insertion of 5 Li’s per formula unit Fe{sub 0.5}TiOPO{sub 4}. Ex-situ XRD reveals a gradual evolution of the structure during cycling of the material, with lower crystallinity after the first discharge cycle. By correlating the electrochemical performances with the structural studies, new insights are achieved into the electrochemical behaviour of the Fe{sub 0.5}TiOPO{sub 4} anode material, suggesting a combination of intercalation and conversion reactions. The Nasicon-type Fe{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3} consists of a three-dimensional network made of corners and edges sharing [TiO{sub 6}] and [FeO{sub 6}] octahedra and [PO{sub 4}] tetrahedra leading to the formation of trimmers [FeTi{sub 2}O{sub 12}]. The first discharge of lithium ion cells based on Fe{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3} materials showed electrochemical activity of Ti{sup 4+}/Ti{sup 3+} and Fe{sup 2+}/Fe{sup 0} couples in the 2.5–1 V region. Below this voltage, the discharge profiles are typical of phosphate systems where Li{sub 3}PO{sub 4} is a product of the electrochemical reaction with lithium; moreover, the electrolyte solvent is reduced. An initial capacities as high as 1100 mA h g{sup −1} can be obtained at deep discharge. However, there is an irreversible capacity

  13. Heat Capacity Changes for Transition-State Analogue Binding and Catalysis with Human 5'-Methylthioadenosine Phosphorylase.

    Science.gov (United States)

    Firestone, Ross S; Cameron, Scott A; Karp, Jerome M; Arcus, Vickery L; Schramm, Vern L

    2017-02-17

    Human 5'-methylthioadenosine phosphorylase (MTAP) catalyzes the phosphorolysis of 5'-methylthioadenosine (MTA). Its action regulates cellular MTA and links polyamine synthesis to S-adenosylmethionine (AdoMet) salvage. Transition state analogues with picomolar dissociation constants bind to MTAP in an entropically driven process at physiological temperatures, suggesting increased hydrophobic character or dynamic structure for the complexes. Inhibitor binding exhibits a negative heat capacity change (-ΔCp), and thus the changes in enthalpy and entropy upon binding are strongly temperature-dependent. The ΔCp of inhibitor binding by isothermal titration calorimetry does not follow conventional trends and is contrary to that expected from the hydrophobic effect. Thus, ligands of increasing hydrophobicity bind with increasing values of ΔCp. Crystal structures of MTAP complexed to transition-state analogues MT-DADMe-ImmA, BT-DADMe-ImmA, PrT-ImmA, and a substrate analogue, MT-tubercidin, reveal similar active site contacts and overall protein structural parameters, despite large differences in ΔCp for binding. In addition, ΔCp values are not correlated with Kd values. Temperature dependence of presteady state kinetics revealed the chemical step for the MTAP reaction to have a negative heat capacity for transition state formation (-ΔCp(‡)). A comparison of the ΔCp(‡) for MTAP presteady state chemistry and ΔCp for inhibitor binding revealed those transition-state analogues most structurally and thermodynamically similar to the transition state. Molecular dynamics simulations of MTAP apoenzyme and complexes with MT-DADMe-ImmA and MT-tubercidin show small, but increased dynamic motion in the inhibited complexes. Variable temperature CD spectroscopy studies for MTAP-inhibitor complexes indicate remarkable protein thermal stability (to Tm = 99 °C) in complexes with transition-state analogues.

  14. Effects of various anesthesia maintenance on serum levels of selenium, copper, zinc, iron and antioxidant capacity

    Directory of Open Access Journals (Sweden)

    Mehmet Akin

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: In this study, we aimed to investigate the effects of sevoflurane, desflurane and propofol maintenances on serum levels of selenium, copper, zinc, iron, malondialdehyde, and glutathion peroxidase measurements, and antioxidant capacity. METHODS: 60 patients scheduled for unilateral lower extremity surgery which would be performed with tourniquet under general anesthesia were divided into three groups. Blood samples were collected to determine the baseline serum levels of selenium, copper, zinc, iron, malondialdehyde and glutathion peroxidase. Anesthesia was induced using 2-2.5 mg kg-1 propofol, 1 mg kg-1 lidocaine and 0.6 mg kg-1 rocuronium. In the maintenance of anesthesia, under carrier gas of 50:50% O2:N2O 4 L min-1, 1 MAC sevoflorane was administered to Group S and 1 MAC desflurane to Group D; and under carrier gas of 50:50% O2:air 4 L min-1 6 mg kg h-1 propofol and 1 µg kg h-1 fentanyl infusion were administered to Group P. At postoperative blood specimens were collected again. RESULTS: It was observed that only in Group S and P, levels of MDA decreased at postoperative 48th hour; levels of glutathion peroxidase increased in comparison to the baseline values. Selenium levels decreased in Group S and Group P, zinc levels decreased in Group P, and iron levels decreased in all three groups, and copper levels did not change in any groups in the postoperative period. CONCLUSION: According to the markers of malondialdehyde and glutathion peroxidase, it was concluded that maintenance of general anesthesia using propofol and sevoflurane activated the antioxidant system against oxidative stress and using desflurane had no effects on oxidative stress and antioxidant system.

  15. [Effects of various anesthesia maintenance on serum levels of selenium, copper, zinc, iron and antioxidant capacity].

    Science.gov (United States)

    Akın, Mehmet; Ayoglu, Hilal; Okyay, Dilek; Ayoglu, Ferruh; Gür, Abdullah; Can, Murat; Yurtlu, Serhan; Hancı, Volkan; Küçükosman, Gamze; Turan, Işıl

    2015-01-01

    In this study, we aimed to investigate the effects of sevoflurane, desflurane and propofol maintenances on serum levels of selenium, copper, zinc, iron, malondialdehyde, and glutathion peroxidase measurements, and antioxidant capacity. 60 patients scheduled for unilateral lower extremity surgery which would be performed with tourniquet under general anesthesia were divided into three groups. Blood samples were collected to determine the baseline serum levels of selenium, copper, zinc, iron, malondialdehyde and glutathion peroxidase. Anesthesia was induced using 2-2.5mgkg(-1) propofol, 1mgkg(-1) lidocaine and 0.6mgkg(-1) rocuronium. In the maintenance of anesthesia, under carrier gas of 50:50% O2:N2O 4Lmin(-1), 1 MAC sevoflorane was administered to Group S and 1 MAC desflurane to Group D; and under carrier gas of 50:50% O2:air 4Lmin(-1) 6mgkgh(-1) propofol and 1μgkgh(-1) fentanyl infusion were administered to Group P. At postoperative blood specimens were collected again. It was observed that only in Group S and P, levels of MDA decreased at postoperative 48th hour; levels of glutathion peroxidase increased in comparison to the baseline values. Selenium levels decreased in Group S and Group P, zinc levels decreased in Group P, and iron levels decreased in all three groups, and copper levels did not change in any groups in the postoperative period. According to the markers of malondialdehyde and glutathion peroxidase, it was concluded that maintenance of general anesthesia using propofol and sevoflurane activated the antioxidant system against oxidative stress and using desflurane had no effects on oxidative stress and antioxidant system. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  16. Phosphorus retention capacity of iron-ore and blast furnace slag in subsurface flow constructed wetlands.

    Science.gov (United States)

    Grüneberg, B; Kern, J

    2001-01-01

    The suitability of iron-ore and blast furnace slag for subsurface flow (SSF) constructed wetlands was studied over a period of four months. Dairy farm wastewater (TP 45 mg l(-1)) was percolated through buckets planted with reed (volume 9.1 l; hydraulic load 151 m(-2) d(-1)). One group of buckets was kept under aerobic conditions and the other group under anaerobic conditions, monitored by continuous redox potential measurements. Even at high mass loading rates of 0.65 g P m(-1) d(-1) the slag provided 98% removal efficiency and showed no decrease in performance with time. However, phosphorus fractionation data indicate that the high phosphorus retention capacity under aerobic conditions is to a great extent attributable to unstable sorption onto calcium compounds (NH4Cl-P). Phosphorus sorption of both the slag (200 microg P g(-1)) and the iron-ore (140 microg P g(-1)) was promoted by predominantly anaerobic conditions due to continuous formation of amorphous ferrous hydroxides. None of the substrates had adverse affects on reed growth.

  17. Copper, iron and the organic ligands that bind them - updates from San Francisco Bay and beyond

    Science.gov (United States)

    Buck, K. N.; Bundy, R.; Biller, D.; Bruland, K. W.; Barbeau, K.

    2015-12-01

    Building on more than 30 years of measurements in San Francisco Bay by Russ Flegal and others, the concentrations of dissolved manganese, iron, cobalt, nickel, copper, zinc, cadmium and lead were determined from a suite of water quality monitoring program stations in North, Central and South Bay using inductively coupled plasma- mass spectrometry following preconcentration on a Nobias-chelate PA1 resin. Given the importance of organic ligands in governing iron solubility and copper bioavailability in natural waters, the organic complexation of dissolved iron and copper in these samples was determined from multiple analytical windows applied to competitive ligand exchange- adsorptive cathodic stripping voltammetry. This study constitutes the first dataset of iron speciation in San Francisco Bay and expands upon prior work evaluating the potential for copper toxicity in this urbanized estuary. Recent advances in voltammetric techniques emerging from a Scientific Committee on Oceanic Research (SCOR) working group on metal-binding ligands in the marine environment, and insights gained from high-resolution ligand measurements from the U.S. GEOTRACES program, highlight how metal-binding ligands in San Francisco Bay compare with those of the coastal and open ocean.

  18. Heavy metal binding capacity (HMBC) of municipal solid waste landfill leachates.

    Science.gov (United States)

    Ward, Marnie L; Bitton, Gabriel; Townsend, Timothy

    2005-07-01

    This research describes the use of a toxicity assay for the identification of metal toxicity, bioavailability and heavy metal binding capacity (HMBC) of municipal solid waste (MSW) landfill leachates. MetPLATE, an assay specific for heavy metal toxicity, was used to determine the HMBC of MSW leachates collected from 14 sites in Florida, with a wide range of chemical and physical characteristics. The leachates displayed a low toxicity which was attributed to the site-specific parameters, including, high concentrations of both organic and inorganic ligands. The HMBC test was undertaken to measure the effect of these site-specific parameters on metal toxicity. The potential for MSW leachate to bind and, thus, detoxify heavy metals was investigated with copper, zinc, and mercury. The HMBC values obtained ranged from 3 to 115, 5 to 93 and 4 to 101 for HMBC-Cu+2, HMBC-Zn+2, and HMBC-Hg+2, respectively. Additionally, the high strength leachates displayed the highest binding capacities, although the landfills sampled represented a wide range of characteristics. For comparison, the HMBC values reported with local lake water, Lake Alice and Lake Beverly, and a wastewater treatment plant effluent were all below 3. A partial fractionation of MSW leachate samples from sites 1, 5 and 8, was conducted to further investigate the influence of selected site-specific physico-chemical parameters on metal binding. The fractionation revealed that the HMBC of the leachate samples was heavily influenced by the concentration of solids, organics and hardness.

  19. COMPARATIVE ANALYSIS FOR METAL BINDING CAPACITY OF CYSTEINE BY USING UV-VIS SPECTROPHOTOMETER

    Directory of Open Access Journals (Sweden)

    Shivendu Ranjan

    2012-05-01

    Full Text Available The metal binding capacity of cysteine with three different metals Nickel, Copper and Lead was studied using UV-Vis spectrophotometer for which absorbance values were taken after interaction of cysteine with metal salt solutions (10ppm and 100ppm. Before taking above absorbance dilution factor was set using cysteine stock. The increase in peak intensity was observed when metal salt solution and metal saltcysteine solution were compared. Based on peak shift and peak intensity finally it can be concluded that the binding capacity of cysteine with Nickel is more, followed by lead and copper. The normal chromophore activity in cysteine is due to the sulphur in which the transition takes place from non bonding orbital’s to the excited antibonding orbital in the range of 210-215nm range. The binding of the metals with cysteine may affect the chromophore activity and may also lead to structural damage of the chromophore. This can give the decrease in the peak intensity or the complete shift in the peak. These results suggest that cysteine metal binding ability can be used for the removal of the metals in water purification. Also this property can be used in removal of metals from our body considering the fact that cysteine may not show adverse effect in the system. So we can go for designing a new type of drug containing cysteine which helps to prevent the accumulation of such metals and thus prevent us from adverse effect.

  20. Function of the iron-binding chelator produced by Coriolus versicolor in lignin biodegradation

    Institute of Scientific and Technical Information of China (English)

    WANG Lu; YAN WenChao; CHEN JiaChuan; HUANG Feng; GAO PeiJi

    2008-01-01

    An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor. This preparation could chelate Fe3+ and reduce Fe3+ to Fe2+, demonstrating that the substance may serve as a ferric chelator,oxygen-reducing agent, and redox-cycling molecule, which would include functioning as the electron transport carrier in Fenton reaction. Lignin was treated with the iron-binding chelator and the changes in structure were investigated by 1H-NMR, 13C-NMR, difference spectrum caused by ionization under alkaline conditions and nitrobenzene oxidation. The results indicated that the iron-binding chelator could destroy the β-O-4 bonds in etherified lignin units and insert phenolic hydroxyl groups. The low-molecular-weight chelator secreted by C. versicolor resulted in new phenolic substructures in the lignin polymer, making it susceptible to attack by laccase or manganese peroxidase. Thus, the synergic action of the iron-binding chelator and the lignocellulolytic enzymes made the substrate more accessible to degradation.

  1. Function of the iron-binding chelator produced by Coriolus versicolor in lignin biodegradation.

    Science.gov (United States)

    Wang, Lu; Yan, WenChao; Chen, JiaChuan; Huang, Feng; Gao, PeiJi

    2008-03-01

    An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor. This preparation could chelate Fe3+ and reduce Fe3+ to Fe2+, demonstrating that the substance may serve as a ferric chelator, oxygen-reducing agent, and redox-cycling molecule, which would include functioning as the electron transport carrier in Fenton reaction. Lignin was treated with the iron-binding chelator and the changes in structure were investigated by 1H-NMR, 13C-NMR, difference spectrum caused by ionization under alkaline conditions and nitrobenzene oxidation. The results indicated that the iron-binding chelator could destroy the beta-O-4 bonds in etherified lignin units and insert phenolic hydroxyl groups. The low-molecular-weight chelator secreted by C. versicolor resulted in new phenolic substructures in the lignin polymer, making it susceptible to attack by laccase or manganese peroxidase. Thus, the synergic action of the iron-binding chelator and the lignocellulolytic enzymes made the substrate more accessible to degradation.

  2. Function of the iron-binding chelator produced by Coriolus versicolor in lignin biodegradation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor. This preparation could chelate Fe3+ and reduce Fe3+ to Fe2+, demonstrating that the substance may serve as a ferric chelator, oxygen-reducing agent, and redox-cycling molecule, which would include functioning as the electron transport carrier in Fenton reaction. Lignin was treated with the iron-binding chelator and the changes in structure were investigated by 1H-NMR, 13C-NMR, difference spectrum caused by ionization under alkaline conditions and nitrobenzene oxidation. The results indicated that the iron-binding chelator could destroy the β-O-4 bonds in etherified lignin units and insert phenolic hydroxyl groups. The low-molecular-weight chelator secreted by C. versicolor resulted in new phenolic substructures in the lignin polymer, making it susceptible to attack by laccase or manganese peroxidase. Thus, the synergic action of the iron-binding chelator and the lignocellulolytic enzymes made the substrate more acces- sible to degradation.

  3. The distribution of iron between the metal-binding sites of transferrin human serum.

    Science.gov (United States)

    Williams, J; Moreton, K

    1980-02-01

    The Makey & Seal [(1976) Biochim. Biophys. Acta 453, 250--256] method of polyacrylamide-gel electrophoresis in buffer containing 6 M-urea was used to determine the distribution of iron between the N-terminal and C-terminal iron-binding sites of transferrin in human serum. In fresh serum the two sites are unequally occupied; there is preferential occupation of the N-terminal site. On incubation of the serum at 37 degrees C the preference of iron for the N-terminal site becomes more marked. On storage of serum at -15 degrees C the iron distribution changes so that there is a marked preference for the C-terminal site. Dialysis of serum against buffer at pH 7.4 also causes iron to be bound much more strongly by the C-terminal than by the N-terminal site. The original preference for the N-terminal site can be resroted to the dialysed serum by addition of the diffusible fraction.

  4. The relation between major histocompatibility complex (MHC) restriction and the capacity of Ia to bind immunogenic peptides

    DEFF Research Database (Denmark)

    Buus, S; Sette, A; Colon, S M;

    1987-01-01

    The capacity of purified I-Ad, I-Ed, I-Ak, and I-Ek to bind to protein derived peptides that have been previously reported to be T cell immunogens has been examined. For each of the 12 peptides studied strong binding to the relevant Ia restriction element was observed. All the peptides bound more...... than one Ia molecule; however, for 11 of 12 peptides, the dominant binding was to the restriction element, whereas in one instance the dominant binding was to a nonrestriction element. When the peptides were used to inhibit the presentation of antigen by prefixed accessory cells to T cells......, an excellent correlation was found between the capacity of a peptide to inhibit the binding of an antigen to purified Ia and the capacity of the peptide to inhibit accessory cell presentation of the antigen. Thus, the binding of peptide to purified Ia is immunologically relevant, and Ia seems to be the only...

  5. Correlation study between sperm concentration, hyaluronic acid-binding capacity and sperm aneuploidy in Hungarian patients.

    Science.gov (United States)

    Mokánszki, Attila; Molnár, Zsuzsanna; Ujfalusi, Anikó; Balogh, Erzsébet; Bazsáné, Zsuzsa Kassai; Varga, Attila; Jakab, Attila; Oláh, Éva

    2012-12-01

    chromosomes and chromosome 17, diploidy and estimated numerical chromosome aberration frequencies were significantly higher in the oligoasthenozoospermic group compared with the three other groups. A significant positive correlation was found between the sperm concentration and the HA-binding capacity, and significant negative correlations between the sperm concentration and the estimated numerical chromosomes aberrations as well as between the HA-binding ability and the estimated numerical chromosome aberrations were identified. We conclude that HA-binding assay and sperm aneuploidy study using FISH may help to predict the reproductive ability of selected infertile male patients and to provide appropriate genetic counselling.

  6. The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-Jin; Lee, Kang-Lok; Kim, Kyoung-Dong; Roe, Jung-Hye, E-mail: jhroe@snu.ac.kr

    2016-09-09

    Iron homeostasis is tightly regulated since iron is an essential but toxic element in the cell. The GATA-type transcription factor Fep1 and its orthologs contribute to iron homeostasis in many fungi by repressing genes for iron uptake when intracellular iron is high. Even though the function and interaction partners of Fep1 have been elucidated extensively In Schizosaccharomyces pombe, the mechanism behind iron-sensing by Fep1 remains elusive. It has been reported that Fep1 interacts with Fe-S-containing monothiol glutaredoxin Grx4 and Grx4-Fra2 complex. In this study, we demonstrate that Fep1 also binds iron, in the form of Fe-S cluster. Spectroscopic and biochemical analyses of as isolated and reconstituted Fep1 suggest that the dimeric Fep1 binds Fe-S clusters. The mutation study revealed that the cluster-binding depended on the conserved cysteines located between the two zinc fingers in the DNA binding domain. EPR analyses revealed [Fe-S]-specific peaks indicative of mixed presence of [2Fe-2S], [3Fe-4S], or [4Fe-4S]. The finding that Fep1 is an Fe-S protein fits nicely with the model that the Fe-S-trafficking Grx4 senses intracellular iron environment and modulates the activity of Fep1. - Highlights: • Fep1, a prototype fungal iron uptake regulator, was isolated stably from Schizosaccharomyces pombe. • Fep1 exhibits UV–visible absorption spectrum, characteristic of [Fe-S] proteins. • The iron and sulfide contents in purified or reconstituted Fep1 also support [Fe-S]. • The conserved cysteines are critical for [Fe-S]-binding. • EPR spectra at 5 K and 123 K suggest a mixed population of [Fe-S].

  7. Comparative study of random and oriented antibody immobilization techniques on the binding capacity of immunosensor.

    Science.gov (United States)

    Kausaite-Minkstimiene, A; Ramanaviciene, A; Kirlyte, J; Ramanavicius, A

    2010-08-01

    A comparative study of four different antibody immobilization techniques that are suitable for modification of surface plasmon resonance (SPR) chip (SPR-chip) is reported. Antibodies against human growth hormone (anti-HGH) were used as the model system. The evaluated SPR-chip modification techniques were (i) random immobilization of intact anti-HGH (intact-anti-HGH) via self-assembled monolayer (SAM) based on 11-mercaptoundecanoic acid (MUA); (ii) random immobilization of intact-anti-HGH within carboxymethyl dextran (CMD) hydrogel by direct covalent amine coupling technique; (iii) oriented coupling of intact-anti-HGH via Fc-fragment to protein-G layer assembled on SAM consisting of MUA (MUA/pG); (iv) oriented immobilization of fragmented anti-HGH antibodies (frag-anti-HGH) via their native thiol-groups directly coupled to the gold. To liberate these thiol groups, the intact-anti-HGH was chemically "divided" into two frag-anti-HGH fragments by chemical reduction with 2-mercaptoethylamine (2-MEA). Optimal concentration of 2-MEA for preparation of anti-HGH was 15 mM. The surface concentration of immobilized antibodies and the antigen binding capacity for all four differently modified SPR-chips was evaluated and compared. The maximum surface concentration of immobilized intact-anti-HGH was obtained by immobilizing the antibody within CMD-hydrogel. The maximal antigen binding capacity was obtained by SPR-chip based on intact-anti-HGH immobilized via MUA/pG. The immobilization based on application of frag-anti-HGH was found to be the most suitable for design of SPR-immunosensor for HGH detection, due to its sufficient antigen binding capacity, simplicity, and low cost in respect to the currently evaluated techniques.

  8. Competition of Chromium on Iron binding sites in the biological system

    Directory of Open Access Journals (Sweden)

    *F. S. Rehmani

    2011-09-01

    Full Text Available Hexavalent chromium is mutagenic and neurotoxic. Trivalent Chromium is involved in the enzymes of glucose metabolism. Chromium is generally found in +3 oxidation state and sometimes it competes for the binding sites of iron in the biological system, when the concentration of chromium exceeds above the normal, it inhibits the absorption of iron and iron deficiency leads diseases such as anemia, tinnitus and depression. Salicylicdhydroxamic acid a hydroxamate type siderophore is used as a drug in the chelation therapy of iron overload patients. The complex formation of Cr(III and Fe(III with salicyclic hydroxamate were studied potentiometrically at different temperatures and data was subjected to computer programs. The stability constant (log beta values and thermodynamic stabilities were calculated. It was found that salicyclic hydroxamate forms 1:1 complex at pH 3 and 1:2 complex at pH 4 with Cr(III and Fe(III, respectively. The stability constant (Log beta and thermodynamic stabilities of Cr(III Salicyclic hydroxamate complexes are close to Fe(III Salicyclic hydroxamate complexes. It was observed from the stability constant values that after chelating therapy the concentration of chromium become low and deficiency symptoms appear resulting diabetes.

  9. Neelaredoxin, an iron-binding protein from the syphilis spirochete, Treponema pallidum, is a superoxide reductase.

    Science.gov (United States)

    Jovanović, T; Ascenso, C; Hazlett, K R; Sikkink, R; Krebs, C; Litwiller, R; Benson, L M; Moura, I; Moura, J J; Radolf, J D; Huynh, B H; Naylor, S; Rusnak, F

    2000-09-15

    Treponema pallidum, the causative agent of venereal syphilis, is a microaerophilic obligate pathogen of humans. As it disseminates hematogenously and invades a wide range of tissues, T. pallidum presumably must tolerate substantial oxidative stress. Analysis of the T. pallidum genome indicates that the syphilis spirochete lacks most of the iron-binding proteins present in many other bacterial pathogens, including the oxidative defense enzymes superoxide dismutase, catalase, and peroxidase, but does possess an orthologue (TP0823) for neelaredoxin, an enzyme of hyperthermophilic and sulfate-reducing anaerobes shown to possess superoxide reductase activity. To analyze the potential role of neelaredoxin in treponemal oxidative defense, we examined the biochemical, spectroscopic, and antioxidant properties of recombinant T. pallidum neelaredoxin. Neelaredoxin was shown to be expressed in T. pallidum by reverse transcriptase-polymerase chain reaction and Western blot analysis. Recombinant neelaredoxin is a 26-kDa alpha(2) homodimer containing, on average, 0.7 iron atoms/subunit. Mössbauer and EPR analysis of the purified protein indicates that the iron atom exists as a mononuclear center in a mixture of high spin ferrous and ferric oxidation states. The fully oxidized form, obtained by the addition of K(3)(Fe(CN)(6)), exhibits an optical spectrum with absorbances at 280, 320, and 656 nm; the last feature is responsible for the protein's blue color, which disappears upon ascorbate reduction. The fully oxidized protein has a A(280)/A(656) ratio of 10.3. Enzymatic studies revealed that T. pallidum neelaredoxin is able to catalyze a redox equilibrium between superoxide and hydrogen peroxide, a result consistent with it being a superoxide reductase. This finding, the first description of a T. pallidum iron-binding protein, indicates that the syphilis spirochete copes with oxidative stress via a primitive mechanism, which, thus far, has not been described in pathogenic

  10. How the binding of human transferrin primes the transferrin receptor potentiating iron release at endosomal pH.

    Science.gov (United States)

    Eckenroth, Brian E; Steere, Ashley N; Chasteen, N Dennis; Everse, Stephen J; Mason, Anne B

    2011-08-09

    Delivery of iron to cells requires binding of two iron-containing human transferrin (hTF) molecules to the specific homodimeric transferrin receptor (TFR) on the cell surface. Through receptor-mediated endocytosis involving lower pH, salt, and an unidentified chelator, iron is rapidly released from hTF within the endosome. The crystal structure of a monoferric N-lobe hTF/TFR complex (3.22-Å resolution) features two binding motifs in the N lobe and one in the C lobe of hTF. Binding of Fe(N)hTF induces global and site-specific conformational changes within the TFR ectodomain. Specifically, movements at the TFR dimer interface appear to prime the TFR to undergo pH-induced movements that alter the hTF/TFR interaction. Iron release from each lobe then occurs by distinctly different mechanisms: Binding of His349 to the TFR (strengthened by protonation at low pH) controls iron release from the C lobe, whereas displacement of one N-lobe binding motif, in concert with the action of the dilysine trigger, elicits iron release from the N lobe. One binding motif in each lobe remains attached to the same α-helix in the TFR throughout the endocytic cycle. Collectively, the structure elucidates how the TFR accelerates iron release from the C lobe, slows it from the N lobe, and stabilizes binding of apohTF for return to the cell surface. Importantly, this structure provides new targets for mutagenesis studies to further understand and define this system.

  11. Iron-binding characterization and polysaccharide production by Klebsiella oxytoca strain isolated from mine acid drainage

    Science.gov (United States)

    Baldi, F; Marchetto, D; Battistel, D; Daniele, S; Faleri, C; De Castro, C; Lanzetta, R

    2009-01-01

    Aims: To investigate Klebsiella oxytoca strain BAS-10 growth on ferric citrate under anaerobic conditions for exopolysaccharide (EPS) production and localization on cell followed by the purification and the EPS determination of the iron-binding stability constant to EPS or biotechnological applications. Methods and Results: Klebsiella oxytoca ferments ferric citrate under anaerobic conditions and produces a ferric hydrogel, whereas ferrous ions were formed in solution. During growth, cells precipitate and a hydrogel formation was observed: the organic material was constituted of an EPS bound to Fe(III) ions, this was found by chemical analyses of the iron species and transmission electron microscopy of the cell cultures. Iron binding to EPS was studied by cyclic voltammetric measurements, either directly on the hydrogel or in an aqueous solutions containing Fe(III)-citrate and purified Fe(III)-EPS. From the voltammetric data, the stability constant for the Fe(III)-EPS complex can be assumed to have values of approx. 1012–1013. It was estimated that this is higher than for the Fe(III)-citrate complex. Conclusions: The production of Fe(III)-EPS under anaerobic conditions is a strategy for the strain to survive in mine drainages and other acidic conditions. This physiological feature can be used to produce large amounts of valuable Fe(III)-EPS, starting from a low cost substrate such as Fe(III)-citrate. Significant and Impact of the Study: The data herein demonstrates that an interesting metal-binding molecule can be produced as a novel catalyst for a variety of potential applications and the EPS itself is a valuable source for rhamnose purification. PMID:19508299

  12. The tumorigenic diversity of the three PLAG family members is associated with different DNA binding capacities.

    Science.gov (United States)

    Hensen, Karen; Van Valckenborgh, Isabelle C C; Kas, Koen; Van de Ven, Wim J M; Voz, Marianne L

    2002-03-01

    Pleomorphic adenoma gene (PLAG) 1, the main translocation target in pleomorphic adenomas of the salivary glands, is a member of a new subfamily of zinc finger proteins comprising the tumor suppressor candidate PLAG-like1 (also called ZAC1 or lost on transformation 1) and PLAGL2. In this report, we show that NIH3T3 cells overexpressing PLAG1 or PLAGL2 display the typical markers of neoplastic transformation: (a) the cells lose cell-cell contact inhibition; (b) show anchorage-independent growth; and (c) are able to induce tumors in nude mice. In contrast, PLAGL1 has been shown to prevent the proliferation of tumor cells by inducing cell cycle arrest and apoptosis. This difference in function is also reflected in their DNA binding, as we show here that the three PLAG proteins, although highly homologous in their DNA-binding domain, bind different DNA sequences in a distinct fashion. Interestingly, the PLAG1- and PLAGL2-induced transformation is accompanied by a drastic up-regulation of insulin-like growth factor-II, which we prove is a target of PLAG1 and PLAGL2. This strongly suggests that the oncogenic capacity of PLAG1 and PLAGL2 is mediated at least partly by activating the insulin-like growth factor-II mitogenic pathway.

  13. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  14. Iron

    Science.gov (United States)

    ... of iron stored in the body become low, iron deficiency anemia sets in. Red blood cells become smaller and ... from the lungs throughout the body. Symptoms of iron deficiency anemia include tiredness and lack of energy, GI upset, ...

  15. Selective Binding of O(2) over N(2) in a Redox-Active Metal-Organic Framework with Open Iron(II) Coordination Sites

    Energy Technology Data Exchange (ETDEWEB)

    Bloch, Eric D; Murray, Leslie J; Queen, Wendy L; Chavan, Sachin; Maximoff, Sergey N; Bigi, Julian P; Krishna, Rajamani; Peterson, Vanessa K; Grandjean, Fernande; Long, Gary J; Smit, Berend; Bordiga, Silvia; Brown, Craig M; Long, Jeffrey R

    2011-09-21

    The air-free reaction between FeCl₂ and H₄dobdc (dobdc{sup 4–} = 2,5-dioxido-1,4-benzenedicarboxylate) in a mixture of N,N-dimethylformamide (DMF) and methanol affords Fe₂(dobdc)·4DMF, a metal–organic framework adopting the MOF-74 (or CPO-27) structure type. The desolvated form of this material displays a Brunauer–Emmett–Teller (BET) surface area of 1360 m²/g and features a hexagonal array of one-dimensional channels lined with coordinatively unsaturated Fe{sup II} centers. Gas adsorption isotherms at 298 K indicate that Fe₂(dobdc) binds O₂ preferentially over N₂, with an irreversible capacity of 9.3 wt %, corresponding to the adsorption of one O₂ molecule per two iron centers. Remarkably, at 211 K, O₂ uptake is fully reversible and the capacity increases to 18.2 wt %, corresponding to the adsorption of one O₂ molecule per iron center. Mössbauer and infrared spectra are consistent with partial charge transfer from iron(II) to O₂ at low temperature and complete charge transfer to form iron(III) and O₂{sup 2–} at room temperature. The results of Rietveld analyses of powder neutron diffraction data (4 K) confirm this interpretation, revealing O₂ bound to iron in a symmetric side-on mode with d{sub O–O} = 1.25(1) Å at low temperature and in a slipped side-on mode with dO–O = 1.6(1) Å when oxidized at room temperature. Application of ideal adsorbed solution theory in simulating breakthrough curves shows Fe₂(dobdc) to be a promising material for the separation of O₂ from air at temperatures well above those currently employed in industrial settings.

  16. Quercetin-Iron Complex: Synthesis, Characterization, Antioxidant, DNA Binding, DNA Cleavage, and Antibacterial Activity Studies.

    Science.gov (United States)

    Raza, Aun; Xu, Xiuquan; Xia, Li; Xia, Changkun; Tang, Jian; Ouyang, Zhen

    2016-11-01

    Quercetin-iron (II) complex was synthesized and characterized by elemental analysis, ultraviolet-visible spectrophotometry, fourier transform infrared spectroscopy, mass spectrometry, proton nuclear magnetic resonance spectroscopy, thermogravimetry and differential scanning calorimetry, scanning electron micrography and molar conductivity. The low molar conductivity value investigates the non-electrolyte nature of the complex. The elemental analysis and other physical and spectroscopic methods reveal the 1:2 stoichiometric ratio (metal:ligand) of the complex. Antioxidant study of the quercetin and its metal complex against 2, 2-di-phenyl-1-picryl hydrazyl radical showed that the complex has much more radical scavenging activity than free quercetin. The interaction of quercetin-iron (II) complex with DNA was determined using ultraviolet visible spectra, fluorescence spectra and agarose gel electrophoresis. The results showed that quercetin-iron (II) complex can intercalate moderately with DNA, quench a strong intercalator ethidium bromide and compete for the intercalative binding sites. The complex showed significant cleavage of pBR 322 DNA from supercoiled form to nicked circular form and these cleavage effects were dose-dependent. Moreover, the mechanism of DNA cleavage indicated that it was an oxidative cleavage pathway. These results revealed the potential nuclease activity of complex to cleave DNA. In addition, antibacterial activity of complex on E.coli and S. aureus was also investigated. The results showed that complex has higher antibacterial activity than ligand.

  17. Assessing the capacity of zero valent iron nanofluids to remediate NAPL-polluted porous media.

    Science.gov (United States)

    Tsakiroglou, Christos; Terzi, Katerina; Sikinioti-Lock, Alexandra; Hajdu, Kata; Aggelopoulos, Christos

    2016-09-01

    A variety of aqueous suspensions (nanofluids) of zero-valent nano-particles (nZVI) are prepared by wet chemistry techniques, their stability and longevity is evaluated by physic-chemical methods of characterization, and their reactivity toward the dechlorination of per-chloro-ethylene (PCE) is examined with tests in batch reactors. For assessing the mobility, longevity and reactivity of nZVI suspensions (nanofluids), under flow-through conditions, visualization multiphase flow and transport tests are performed on a glass-etched pore network. The nZVI breakthrough curves are constructed by measuring the transient variation of the iron concentration in the effluent with atomic absorption spectroscopy. The capacity of nZVI to remediate the bulk phase of PCE is quantified by detecting the mass loss rate of PCE ganglia trapped in glass-etched pore networks during the continuous injection of nZVI suspension or pure water. The nZVI injection in porous media is simulated as an advection- dispersion process by accounting for the attachment/detachment of nanoparticles on the pore-walls, and describing the kinetics of PCE dissolution and reaction by 1st order equations. Visualization experiments reveal that the gradual elimination of PCE ganglia by the injected nZVI is associated with the preferential "erosion" of the upstream interfacial regions. The step controlling the overall process kinetics might be either (i) the enhanced PCE dissolution or (ii) the direct reaction of bulk PCE with the nZVI deposited upon the ganglia interfaces. Inverse modeling of the experiments under the simplifying assumption of one active mechanism indicates that the estimated kinetic coefficients are increasing functions of the flow rate.

  18. A synthetic peptide with the putative iron binding motif of amyloid precursor protein (APP) does not catalytically oxidize iron.

    Science.gov (United States)

    Ebrahimi, Kourosh Honarmand; Hagedoorn, Peter-Leon; Hagen, Wilfred R

    2012-01-01

    The β-amyloid precursor protein (APP), which is a key player in Alzheimer's disease, was recently reported to possess an Fe(II) binding site within its E2 domain which exhibits ferroxidase activity [Duce et al. 2010, Cell 142: 857]. The putative ligands of this site were compared to those in the ferroxidase site of ferritin. The activity was indirectly measured using transferrin, which scavenges the Fe(III) product of the reaction. A 22-residue synthetic peptide, named FD1, with the putative ferroxidase site of APP, and the E2 domain of APP were each reported to exhibit 40% of the ferroxidase activity of APP and of ceruloplasmin. It was also claimed that the ferroxidase activity of APP is inhibited by Zn(II) just as in ferritin. We measured the ferroxidase activity indirectly (i) by the incorporation of the Fe(III) product of the ferroxidase reaction into transferrin and directly (ii) by monitoring consumption of the substrate molecular oxygen. The results with the FD1 peptide were compared to the established ferroxidase activities of human H-chain ferritin and of ceruloplasmin. For FD1 we observed no activity above the background of non-enzymatic Fe(II) oxidation by molecular oxygen. Zn(II) binds to transferrin and diminishes its Fe(III) incorporation capacity and rate but it does not specifically bind to a putative ferroxidase site of FD1. Based on these results, and on comparison of the putative ligands of the ferroxidase site of APP with those of ferritin, we conclude that the previously reported results for ferroxidase activity of FD1 and - by implication - of APP should be re-evaluated.

  19. A synthetic peptide with the putative iron binding motif of amyloid precursor protein (APP does not catalytically oxidize iron.

    Directory of Open Access Journals (Sweden)

    Kourosh Honarmand Ebrahimi

    Full Text Available The β-amyloid precursor protein (APP, which is a key player in Alzheimer's disease, was recently reported to possess an Fe(II binding site within its E2 domain which exhibits ferroxidase activity [Duce et al. 2010, Cell 142: 857]. The putative ligands of this site were compared to those in the ferroxidase site of ferritin. The activity was indirectly measured using transferrin, which scavenges the Fe(III product of the reaction. A 22-residue synthetic peptide, named FD1, with the putative ferroxidase site of APP, and the E2 domain of APP were each reported to exhibit 40% of the ferroxidase activity of APP and of ceruloplasmin. It was also claimed that the ferroxidase activity of APP is inhibited by Zn(II just as in ferritin. We measured the ferroxidase activity indirectly (i by the incorporation of the Fe(III product of the ferroxidase reaction into transferrin and directly (ii by monitoring consumption of the substrate molecular oxygen. The results with the FD1 peptide were compared to the established ferroxidase activities of human H-chain ferritin and of ceruloplasmin. For FD1 we observed no activity above the background of non-enzymatic Fe(II oxidation by molecular oxygen. Zn(II binds to transferrin and diminishes its Fe(III incorporation capacity and rate but it does not specifically bind to a putative ferroxidase site of FD1. Based on these results, and on comparison of the putative ligands of the ferroxidase site of APP with those of ferritin, we conclude that the previously reported results for ferroxidase activity of FD1 and - by implication - of APP should be re-evaluated.

  20. Plasma TNF binding capacity profiles during treatment with etanercept in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Gudbrandsdottir, S; Bliddal, H; Petri, A;

    2004-01-01

    Etanercept (Enbrel) induces a rapid and sustained decline in disease activity in the majority of patients with refractory rheumatoid arthritis (RA). In these patients neutralization of TNFalpha and lymphotoxin (LT), previously termed TNFbeta is mediated by etanercept itself, as well as by naturally...... occurring soluble TNF receptors. However, the clinical response to treatment with etanercept may vary. Previously, pharmacokinetic studies have focused on the molar concentrations of etanercept, but very little is known about the kinetics of bioactive etanercept in patients treated with etanercept....... The purpose of this study was to evaluate kinetics, including inter- and intraindividual variations of the total TNF binding capacity, in RA patients who were on a standard treatment schedule with etanercept....

  1. [Is cobalt-binding capacity of serum a new perspective diagnostic marker?].

    Science.gov (United States)

    Litus, E A; Zaĭtsev, V G; Verovskiĭ, V E; Goncharova, L V; Dudchenko, G P; Ostrovskiĭ, O V

    2014-01-01

    The aim of this study was to determine the reference interval of serum cobalt-binding capacity (CoBC) and to estimate the effect of factors unrelated to oxidative modification of serum albumin on this diagnostic marker. A group of healthy volunteers (n=194), a group of patients with autoimmune diseases (n=44) and a group of patients with diabetes type 2 (n=50) participated in this study. The regional reference interval was found to be 0,462-0,744 mmol Co 2+ /l of serum. The study of serum CoBC in two groups of patients showed that the CoBC level strongly depends on the serum protein profile. Therefore, this diagnostic test may be used for diagnosing ischemia, but other pathologies associated with changes in a ratio of blood protein fractions can also influence the serum CoBC level.

  2. RNA-Binding Proteins in Trichomonas vaginalis: Atypical Multifunctional Proteins Involved in a Posttranscriptional Iron Regulatory Mechanism

    Science.gov (United States)

    Figueroa-Angulo, Elisa E.; Calla-Choque, Jaeson S.; Mancilla-Olea, Maria Inocente; Arroyo, Rossana

    2015-01-01

    Iron homeostasis is highly regulated in vertebrates through a regulatory system mediated by RNA-protein interactions between the iron regulatory proteins (IRPs) that interact with an iron responsive element (IRE) located in certain mRNAs, dubbed the IRE-IRP regulatory system. Trichomonas vaginalis, the causal agent of trichomoniasis, presents high iron dependency to regulate its growth, metabolism, and virulence properties. Although T. vaginalis lacks IRPs or proteins with aconitase activity, possesses gene expression mechanisms of iron regulation at the transcriptional and posttranscriptional levels. However, only one gene with iron regulation at the transcriptional level has been described. Recently, our research group described an iron posttranscriptional regulatory mechanism in the T. vaginalis tvcp4 and tvcp12 cysteine proteinase mRNAs. The tvcp4 and tvcp12 mRNAs have a stem-loop structure in the 5'-coding region or in the 3'-UTR, respectively that interacts with T. vaginalis multifunctional proteins HSP70, α-Actinin, and Actin under iron starvation condition, causing translation inhibition or mRNA stabilization similar to the previously characterized IRE-IRP system in eukaryotes. Herein, we summarize recent progress and shed some light on atypical RNA-binding proteins that may participate in the iron posttranscriptional regulation in T. vaginalis. PMID:26703754

  3. Acanthamoeba castellanii Proteases are Capable of Degrading Iron-Binding Proteins as a Possible Mechanism of Pathogenicity.

    Science.gov (United States)

    Ramírez-Rico, Gerardo; Martínez-Castillo, Moisés; de la Garza, Mireya; Shibayama, Mineko; Serrano-Luna, Jesús

    2015-01-01

    Acanthamoeba castellanii, a free-living amoeba, is an amphizoic organism that can behave as an opportunistic pathogen, causing granulomatous amoebic encephalitis in immunocompromised patients or infecting immunocompetent individuals via cutaneous lesions, sinusoidal infections, or amoebic keratitis. Therefore, this amoeba could be in contact with different iron-binding proteins, such as lactoferrin in tears and mucosa and transferrin and hemoglobin in blood. Iron is a vital and necessary element for host metabolism but also for parasite survival. Accordingly, parasites have developed iron uptake mechanisms, one of which is the utilization of proteases to degrade host iron-binding proteins. In this work, we performed a partial biochemical characterization of A. castellanii proteases at different pHs and utilizing protease inhibitors with 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and copolymerized with different iron-binding proteins. We describe for the first time the presence of several cysteine proteases in a total A. castellanii crude extract and in conditioned culture medium precipitated with ethanol. These amoebic peptidases degraded human holo-lactoferrin, holo-transferrin, hemoglobin, and horse spleen ferritin; some of these proteases were substrate specific, and others degraded multiple substrates. These proteases could be considered virulence factors that promote iron acquisition from the host.

  4. Iron-binding Ligands in the Eastern Tropical South Pacific: Results from U.S. GEOTRACES Cruise GP16

    Science.gov (United States)

    Buck, K. N.; Fitzsimmons, J. N.; Sherrell, R. M.; Sohst, B. M.; Sedwick, P.; John, S.

    2016-02-01

    High-resolution depth profiles, consisting of 25-49 samples each, were collected as part of the U.S. GEOTRACES Eastern Pacific Zonal Transect (GEOTRACES cruise GP16). The organic complexation of dissolved iron in these samples, including the concentrations and conditional stability constants of iron-binding ligands, was measured by competitive ligand exchange-adsorptive cathodic stripping voltammetry using the added competitive ligand salicylaldoxime. In addition to the conventional depth profile samples for dissolved (<0.2 µm) iron-binding ligands, samples were collected for size-fractionated ligand analyses using cross flow filtration. These samples were obtained from in and around the mid-depth near-field to distal hydrothermal plume emanating from the East Pacific Rise, and allowed for iron-binding ligand analyses in the dissolved (<0.45 µm), colloidal (10 kDa to 0.45 µm) and soluble (<10 kDa) size fractions. Results from this work will be presented in the context of the few previous studies of iron-binding ligands in the South Pacific, and compared with results from the North U.S. GEOTRACES North Atlantic Transect (GEOTRACES cruise GA03).

  5. Effects of acute creatine supplementation on iron homeostasis and uric acid-based antioxidant capacity of plasma after wingate test

    Directory of Open Access Journals (Sweden)

    Barros Marcelo P

    2012-06-01

    Full Text Available Abstract Background Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 ± 5.8 years old immediately before and 5 and 60 min after the exhaustive Wingate test. Results Maximum anaerobic power was improved by acute creatine supplementation (10.5 %, but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP, leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. Conclusions Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent and inherent antioxidant activity of creatine.

  6. Effects of acute creatine supplementation on iron homeostasis and uric acid-based antioxidant capacity of plasma after wingate test.

    Science.gov (United States)

    Barros, Marcelo P; Ganini, Douglas; Lorenço-Lima, Leandro; Soares, Chrislaine O; Pereira, Benedito; Bechara, Etelvino Jh; Silveira, Leonardo R; Curi, Rui; Souza-Junior, Tacito P

    2012-06-12

    Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 ± 5.8 years old) immediately before and 5 and 60 min after the exhaustive Wingate test. Maximum anaerobic power was improved by acute creatine supplementation (10.5 %), but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP), leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent) and inherent antioxidant activity of creatine.

  7. On-board capacity estimation of lithium iron phosphate batteries by means of half-cell curves

    Science.gov (United States)

    Marongiu, Andrea; Nlandi, Nsombo; Rong, Yao; Sauer, Dirk Uwe

    2016-08-01

    This paper presents a novel methodology for the on-board estimation of the actual battery capacity of lithium iron phosphate batteries. The approach is based on the detection of the actual degradation mechanisms by collecting plateau information. The tracked degradation modes are employed to change the characteristics of the fresh electrode voltage curves (mutual position and dimension), to reconstruct the full voltage curve and therefore to obtain the total capacity. The work presents a model which describes the relation between the single degradation modes and the electrode voltage curves characteristics. The model is then implemented in a novel battery management system structure for aging tracking and on-board capacity estimation. The working principle of the new algorithm is validated with data obtained from lithium iron phosphate cells aged in different operating conditions. The results show that both during charge and discharge the algorithm is able to correctly track the actual battery capacity with an error of approx. 1%. The use of the obtained results for the recalibration of a hysteresis model present in the battery management system is eventually presented, demonstrating the benefit of the tracked aging information for additional scopes.

  8. Assessing the capacity of zero valent iron nanofluids to remediate NAPL-polluted porous media

    Energy Technology Data Exchange (ETDEWEB)

    Tsakiroglou, Christos, E-mail: ctsakir@iceht.forth.gr [Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras (Greece); Terzi, Katerina; Sikinioti-Lock, Alexandra [Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras (Greece); Department of Chemical Engineering, University of Patras, 26504 Patras (Greece); Hajdu, Kata; Aggelopoulos, Christos [Foundation for Research and Technology Hellas-Institute of Chemical Engineering Sciences, Stadiou street, Platani, 26504 Patras (Greece)

    2016-09-01

    A variety of aqueous suspensions (nanofluids) of zero-valent nano-particles (nZVI) are prepared by wet chemistry techniques, their stability and longevity is evaluated by physic-chemical methods of characterization, and their reactivity toward the dechlorination of per-chloro-ethylene (PCE) is examined with tests in batch reactors. For assessing the mobility, longevity and reactivity of nZVI suspensions (nanofluids), under flow-through conditions, visualization multiphase flow and transport tests are performed on a glass-etched pore network. The nZVI breakthrough curves are constructed by measuring the transient variation of the iron concentration in the effluent with atomic absorption spectroscopy. The capacity of nZVI to remediate the bulk phase of PCE is quantified by detecting the mass loss rate of PCE ganglia trapped in glass-etched pore networks during the continuous injection of nZVI suspension or pure water. The nZVI injection in porous media is simulated as an advection- dispersion process by accounting for the attachment/detachment of nanoparticles on the pore-walls, and describing the kinetics of PCE dissolution and reaction by 1st order equations. Visualization experiments reveal that the gradual elimination of PCE ganglia by the injected nZVI is associated with the preferential “erosion” of the upstream interfacial regions. The step controlling the overall process kinetics might be either (i) the enhanced PCE dissolution or (ii) the direct reaction of bulk PCE with the nZVI deposited upon the ganglia interfaces. Inverse modeling of the experiments under the simplifying assumption of one active mechanism indicates that the estimated kinetic coefficients are increasing functions of the flow rate. - Highlights: • The PCE remediation by nZVI is studied with visualization tests on pore networks. • The remediation of PCE ganglia by nZVI follows a non-uniform “erosion” pattern. • The preferential erosion of the upstream interfacial regions of

  9. Increases thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase by fusion of cellulose binding domain derived from Trichoderma reesei

    Energy Technology Data Exchange (ETDEWEB)

    Thongekkaew, Jantaporn, E-mail: jantaporn_25@yahoo.com [Department of Biological Science, Faculty of Science, Ubon-Ratchathani University, Warinchumrab, Ubon-Ratchathani 34190 (Thailand); Ikeda, Hiroko; Iefuji, Haruyuki [Application Research Division, National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer The CSLP and fusion enzyme were successfully expressed in the Pichia pastoris. Black-Right-Pointing-Pointer The fusion enzyme was stable at 80 Degree-Sign C for 120-min. Black-Right-Pointing-Pointer The fusion enzyme was responsible for cellulose-binding capacity. Black-Right-Pointing-Pointer The fusion enzyme has an attractive applicant for enzyme immobilization. -- Abstract: To improve the thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase (CSLP), the cellulose-binding domain originates from Trichoderma reesei cellobiohydrolase I was engineered into C-terminal region of the CSLP (CSLP-CBD). The CSLP and CSLP-CBD were successfully expressed in the Pichia pastoris using the strong methanol inducible alcohol oxidase 1 (AOX1) promoter and the secretion signal sequence from Saccharomyces cerevisiae ({alpha} factor). The recombinant CSLP and CSLP-CBD were secreted into culture medium and estimated by SDS-PAGE to be 22 and 27 kDa, respectively. The fusion enzyme was stable at 80 Degree-Sign C and retained more than 80% of its activity after 120-min incubation at this temperature. Our results also found that the fusion of fungal exoglucanase cellulose-binding domain to CSLP is responsible for cellulose-binding capacity. This attribute should make it an attractive applicant for enzyme immobilization.

  10. Study of Water Binding Capacity, pH, Chemical Composition and Microstructure of Livestock Meat and Poultry

    OpenAIRE

    Eleonora Okuskhanova; Maksim Rebezov; Zhanibek Yessimbekov; Anuarbek Suychinov; Natalya Semenova; Yaroslav Rebezov; Olga Gorelik; Oksana Zinina

    2017-01-01

    This paper shows the results of analysis of chemical composition, water binding capacity, pH and microstructure of maral meat, goat meat, lamb, and turkey meat. From the analysis, the high content of protein and ash is observed in turkey meat, fat prevails in lamb, and less amount in maral meat and goat meat. pH value lies between 5.7 (turkey white meat) and 6.4 (goat meat). Low value of water binding capacity is detected in turkey meat (58.2% in red meat, 59.2% in white meat) and high value ...

  11. Visualization of Iron-Binding Micelles in Acidic Recombinant Biomineralization Protein, MamC

    Energy Technology Data Exchange (ETDEWEB)

    Kashyap, Sanjay [Ames Laboratory; Woehl, Taylor [Ames Laboratory; Valverde-Tercedor, Carmen [University of Granada; Sanchez-Quesada, Miguel [University of Granada; Lopez, Concepcion Jimenez [University of Granada; Prozorov, Tanya [Ames Laboratory

    2014-03-07

    Biological macromolecules are utilized in low-temperature synthetic methods to exert precise control over nanoparticle nucleation and placement. They enable low-temperature formation of a variety of functional nanostructured materials with properties often not achieved via conventional synthetic techniques. Here we report on the in situ visualization of a novel acidic bacterial recombinant protein, MamC, commonly present in the magnetosome membrane of several magnetotactic bacteria, including Magnetococcus marinus, strain MC-1. Our findings provide an insight into the self-assembly of MamC and point to formation of the extended protein surface, which is assumed to play an important role in the formation of biotemplated inorganic nanoparticles. The self-organization of MamC is compared to the behavior of another acidic recombinant iron-binding protein, Mms6.

  12. Visualization of Iron-Binding Micelles in Acidic Recombinant Biomineralization Protein, MamC

    Directory of Open Access Journals (Sweden)

    Sanjay Kashyap

    2014-01-01

    Full Text Available Biological macromolecules are utilized in low-temperature synthetic methods to exert precise control over nanoparticle nucleation and placement. They enable low-temperature formation of a variety of functional nanostructured materials with properties often not achieved via conventional synthetic techniques. Here we report on the in situ visualization of a novel acidic bacterial recombinant protein, MamC, commonly present in the magnetosome membrane of several magnetotactic bacteria, including Magnetococcus marinus, strain MC-1. Our findings provide an insight into the self-assembly of MamC and point to formation of the extended protein surface, which is assumed to play an important role in the formation of biotemplated inorganic nanoparticles. The self-organization of MamC is compared to the behavior of another acidic recombinant iron-binding protein, Mms6.

  13. Predicting copper-, iron- and zinc-binding proteins in pathogenic species of the Paracoccidioides genus

    Directory of Open Access Journals (Sweden)

    Gabriel B Tristao

    2015-01-01

    Full Text Available Approximately one-third of all proteins have been estimated to contain at least one metal cofactor, and these proteins are referred to as metalloproteins. These represent one of the most diverse classes of proteins, containing metal ions that bind to specific sites to perform catalytic, regulatory and structural functions. Bioinformatic tools have been developed to predict metalloproteins encoded by an organism based only on its genome sequence. Its function and the type of metal binder can also be predicted via a bioinformatics approach. Paracoccidioides complex includes termodimorphic pathogenic fungi that are found as saprobic mycelia in the environment and as yeast, the parasitic form, in host tissues. They are the etiologic agents of Paracoccidioidomycosis, a prevalent systemic mycosis in Latin America. Many metalloproteins are important for the virulence of several pathogenic microorganisms. Accordingly, the present work aimed to predict the cooper, iron and zinc proteins encoded by the genomes of three phylogenetic species of Paracoccidioides (Pb01, Pb03 and Pb18. The metalloproteins were identified using bioinformatics approaches based on structure, annotation and domains. Cu-, Fe- and Zn-binding proteins represent 7% of the total proteins encoded by Paracoccidioides spp. genomes. Zinc proteins were the most abundant metalloproteins, representing 5.7% of the fungus proteome, whereas copper and iron proteins represent 0.3% and 1.2%, respectively. Functional classification revealed that metalloproteins are related to many cellular processes. Furthermore, it was observed that many of these metalloproteins serve as virulence factors in the biology of the fungus. Thus, it is concluded that the Cu, Fe and Zn metalloproteomes of the Paracoccidioides spp. are of the utmost importance for the biology and virulence of these particular human pathogens.

  14. Iron Oxide Surface Chemistry: The Effect of Chemical Structure on Binding in Benzoic Acid and Catechol Derivatives.

    Science.gov (United States)

    Korpany, Katalin V; Majewski, Dorothy D; Chiu, Cindy T; Cross, Shoronia N; Blum, Amy Szuchmacher

    2017-02-18

    Excellent performance of functionalized iron oxide nanoparticles in nanomaterial and biomedical applications often relies on achieving attachment of ligands to the iron oxide surface both in sufficient number and with proper orientation. Towards this end, we determine relationships between ligand chemical structure and surface binding on magnetic iron oxide nanoparticles for a series of related benzoic acid and catechol derivatives. Ligand exchange was used to introduce the model ligands, and the resulting nanoparticles were characterized by FTIR-ATR, transmission electron microscopy (TEM), and nanoparticle solubility behavior. An in-depth analysis of ligand electronic effects and reaction conditions reveals that the nature of ligand binding does not solely depend on the presence of functional groups known to bind to iron oxide nanoparticles. The structure of the resulting ligand-surface complex was primarily influenced by the relative positioning of hydroxyl and carboxylic acid groups within the ligand as well as whether or not HCl(aq) was added to the ligand exchange reaction. Overall, this study will help guide future ligand design and ligand exchange strategies towards realizing truly custom-built iron oxide nanoparticles.

  15. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    The interest in the role of ferrous iron in diabetes pathophysiology has been revived by recent evidence of iron as an important determinant of pancreatic islet inflammation and as a biomarker of diabetes risk and mortality. The iron metabolism in the β-cell is complex. Excess free iron is toxic......, but at the same time, iron is required for normal β-cell function and thereby glucose homeostasis. In the pathogenesis of diabetes, iron generates reactive oxygen species (ROS) by participating in the Fenton chemistry, which can induce oxidative damage and apoptosis. The aim of this review is to present...... and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...

  16. Yield point of iron materials in dependence of lattice binding and microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, H.; Hildebrand, M. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Metallformung

    2001-11-01

    Ferritic/perlitic iron materials with {proportional_to}0.35% C and alloying elements of the groups III A/B to VIII of the periodic table (PT) showed that values of the yield point, measured statically by tension tests, do not only depend on the kind of alloying element or its content, but that they also depend on the microstructure (grain size and phase arrangement of the second phase M{sub 3}C) in polycrystals. In the same way that the minimum of lattice binding between two neighbouring atoms (or ions) of the same kind is at half distance between them and corresponds to the equilibrium, we can find the yield point of polycrystals at distinct grain sizes (after thermal treatment) as well. The yield point behaves like the Young modulus, which is an expression of lattice binding. It should be noted that added alloying elements can accelerate the grain growth, but there are also cases where these elements cause hindrance. To raise the yield point the non-equilibrium states on both sides of the determined minimum of yield point should be used, which depends on the grain size (and heat-treatment conditions). This is especially meaningful for the employment of steel sheets in the car industry. (orig.)

  17. Effect of carboxymethylation conditions on the water-binding capacity of chitosan-based superabsorbents.

    Science.gov (United States)

    Bidgoli, Hosein; Zamani, Akram; Taherzadeh, Mohammad J

    2010-12-10

    A superabsorbent polymer (SAP) from chitosan was provided via carboxymethylation of chitosan, followed by cross-linking with glutaraldehyde and freeze-drying. This work was focused on an investigation of the effects of monochloroacetic acid (MCAA), sodium hydroxide, and reaction time on preparation of carboxymethyl chitosan (CMCS). The CMCS products were characterized using FTIR spectroscopy, and their degrees of substitution (DS) were measured using conductimetry and FTIR analysis. The highest DS value was obtained when the carboxymethylation reaction was carried out using 1.75g MCAA and 1.75g NaOH per g of chitosan in 4h. The water solubilities of the CMCS products at various pHs were also evaluated, and the results indicated a significant impact of the reaction parameters on the solubility of CMCS. The CMCSs with the highest DS value resulted in SAPs having the highest water-binding capacity (WBC). The WBC of the best SAP measured after 10min exposure in distilled water, 0.9% NaCl solution, synthetic urine, and artificial blood was 104, 33, 30, and 57g/g, respectively. The WBC of this SAP at pH 2-9 passed a maximum at pH 6.

  18. "Off-Target" (18)F-AV-1451 Binding in the Basal Ganglia Correlates with Age-Related Iron Accumulation.

    Science.gov (United States)

    Choi, Jae Yong; Cho, Hanna; Ahn, Sung Jun; Lee, Jae Hoon; Ryu, Young Hoon; Lee, Myung Sik; Lyoo, Chul Hyoung

    2017-08-03

    Backgrounds: "Off-target" binding in the basal ganglia is commonly observed in the (18)F-AV-1451 positron emission tomography (PET) studies of the elderly. We sought to investigate the relationship between this phenomenon in the basal ganglia and iron accumulation using iron-sensitive R2(*) magnetic resonance (MR) imaging. Methods: 59 healthy controls and 61 patients with Alzheimer's disease and mild cognitive impairment (AD/MCI) underwent (18)F-AV-1451 PET and R2(*) MR imaging studies. A correlation analysis was performed for age, (18)F-AV-1451 binding, and R2(*) values. Results: There was an age-related increase in both (18)F-AV-1451 binding in the basal ganglia and R2(*) values in the putamen in both the controls and AD/MCI patients. (18)F-AV-1451 binding in the basal ganglia increased with R2(*) values. Conclusion: "Off-target" (18)F-AV-1451 binding in the basal ganglia is associated with the age-related increases in iron accumulation. Postmortem studies are required to further investigate the nature of this association. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  19. Iron stress increases Bordetella pertussis mucin-binding capacity and attachment to respiratory epithelial cells

    NARCIS (Netherlands)

    Perez Vidakovics, Maria L. A.; Lamberti, Yanina; Serra, Diego; Berbers, Guy A. M.; van der Pol, W.-Ludo; Rodriguez, Maria Eugenia

    2007-01-01

    Whooping cough is a reemerging infectious disease of the respiratory tract caused by Bordetella pertussis. The incomplete understanding of the molecular mechanisms of host colonization hampers the efforts to control this disease. Among the environmental factors that commonly determine the bacterial

  20. A study on the effects of pica and iron-deficiency anemia on oxidative stress, antioxidant capacity and trace elements.

    Science.gov (United States)

    Bay, A; Dogan, M; Bulan, K; Kaba, S; Demir, N; Öner, A F

    2013-09-01

    Pica is defined as developmentally inappropriate consumption of nonnutritive substances for at least 1 month. There are a few studies on serum trace element levels of patients with pica. The literature contains contracting data on the levels of oxidative stress and antioxidant levels in patients with iron-deficiency anemia (IDA). The effect of pica on oxidative stress and antioxidant capacity has not been investigated yet. The present study evaluated the effects of pica and IDA on oxidative stress and antioxidant capacity as well as on the levels of trace elements including serum zinc and selenium in 47 children with IDA plus pica, 22 children with IDA only and 21 nonanemic children as controls. The results demonstrated significantly lower levels of serum selenium and zinc in pica and IDA groups compared to the control group. Total oxidant levels were highest in the pica group and consistently, the lowest total antioxidant capacity was observed again in the pica group. Comparison of pica and IDA groups yielded significantly lower levels of total antioxidant levels and significantly higher oxidative stress index in the pica group. Consequently, it is thought that the detrimental effects of pica within the organism were mediated by adverse impacts on antioxidant capacity and oxidative stress. These effects should be kept in mind while managing patients with pica.

  1. Specific erythrocyte binding capacity and biological activity of Plasmodium falciparum erythrocyte binding ligand 1 (EBL-1)-derived peptides.

    Science.gov (United States)

    Curtidor, Hernando; Rodríguez, Luis E; Ocampo, Marisol; López, Ramses; García, Javier E; Valbuena, John; Vera, Ricardo; Puentes, Alvaro; Vanegas, Magnolia; Patarroyo, Manuel E

    2005-02-01

    Erythrocyte binding ligand 1 (EBL-1) is a member of the ebl multigene family involved in Plasmodium falciparum invasion of erythrocytes. We found that five EBL-1 high-activity binding peptides (HABPs) bound specifically to erythrocytes: 29895 ((41)HKKKSGELNNNKSGILRSTY(60)), 29903 ((201)LYECGK-KIKEMKWICTDNQF(220)), 29923 ((601)CNAILGSYADIGDIVRGLDV(620)), 29924((621)WRDINTNKLSEK-FQKIFMGGY(640)), and 30018 ((2481)LEDIINLSKKKKKSINDTSFY(2500)). We also show that binding was saturable, not sialic acid-dependent, and that all peptides specifically bound to a 36-kDa protein on the erythrocyte membrane. The five HABPs inhibited in vitro merozoite invasion depending on the peptide concentration used, suggesting their possible role in the invasion process.

  2. LRRK2 kinase activity is dependent on LRRK2 GTP binding capacity but independent of LRRK2 GTP binding.

    Science.gov (United States)

    Taymans, Jean-Marc; Vancraenenbroeck, Renée; Ollikainen, Petri; Beilina, Alexandra; Lobbestael, Evy; De Maeyer, Marc; Baekelandt, Veerle; Cookson, Mark R

    2011-01-01

    Leucine rich repeat kinase 2 (LRRK2) is a Parkinson's disease (PD) gene that encodes a large multidomain protein including both a GTPase and a kinase domain. GTPases often regulate kinases within signal transduction cascades, where GTPases act as molecular switches cycling between a GTP bound "on" state and a GDP bound "off" state. It has been proposed that LRRK2 kinase activity may be increased upon GTP binding at the LRRK2 Ras of complex proteins (ROC) GTPase domain. Here we extensively test this hypothesis by measuring LRRK2 phosphorylation activity under influence of GDP, GTP or non-hydrolyzable GTP analogues GTPγS or GMPPCP. We show that autophosphorylation and lrrktide phosphorylation activity of recombinant LRRK2 protein is unaltered by guanine nucleotides, when co-incubated with LRRK2 during phosphorylation reactions. Also phosphorylation activity of LRRK2 is unchanged when the LRRK2 guanine nucleotide binding pocket is previously saturated with various nucleotides, in contrast to the greatly reduced activity measured for the guanine nucleotide binding site mutant T1348N. Interestingly, when nucleotides were incubated with cell lysates prior to purification of LRRK2, kinase activity was slightly enhanced by GTPγS or GMPPCP compared to GDP, pointing to an upstream guanine nucleotide binding protein that may activate LRRK2 in a GTP-dependent manner. Using metabolic labeling, we also found that cellular phosphorylation of LRRK2 was not significantly modulated by nucleotides, although labeling is significantly reduced by guanine nucleotide binding site mutants. We conclude that while kinase activity of LRRK2 requires an intact ROC-GTPase domain, it is independent of GDP or GTP binding to ROC.

  3. LRRK2 kinase activity is dependent on LRRK2 GTP binding capacity but independent of LRRK2 GTP binding.

    Directory of Open Access Journals (Sweden)

    Jean-Marc Taymans

    Full Text Available Leucine rich repeat kinase 2 (LRRK2 is a Parkinson's disease (PD gene that encodes a large multidomain protein including both a GTPase and a kinase domain. GTPases often regulate kinases within signal transduction cascades, where GTPases act as molecular switches cycling between a GTP bound "on" state and a GDP bound "off" state. It has been proposed that LRRK2 kinase activity may be increased upon GTP binding at the LRRK2 Ras of complex proteins (ROC GTPase domain. Here we extensively test this hypothesis by measuring LRRK2 phosphorylation activity under influence of GDP, GTP or non-hydrolyzable GTP analogues GTPγS or GMPPCP. We show that autophosphorylation and lrrktide phosphorylation activity of recombinant LRRK2 protein is unaltered by guanine nucleotides, when co-incubated with LRRK2 during phosphorylation reactions. Also phosphorylation activity of LRRK2 is unchanged when the LRRK2 guanine nucleotide binding pocket is previously saturated with various nucleotides, in contrast to the greatly reduced activity measured for the guanine nucleotide binding site mutant T1348N. Interestingly, when nucleotides were incubated with cell lysates prior to purification of LRRK2, kinase activity was slightly enhanced by GTPγS or GMPPCP compared to GDP, pointing to an upstream guanine nucleotide binding protein that may activate LRRK2 in a GTP-dependent manner. Using metabolic labeling, we also found that cellular phosphorylation of LRRK2 was not significantly modulated by nucleotides, although labeling is significantly reduced by guanine nucleotide binding site mutants. We conclude that while kinase activity of LRRK2 requires an intact ROC-GTPase domain, it is independent of GDP or GTP binding to ROC.

  4. Monothiol CGFS glutaredoxins and BolA-like proteins: [2Fe-2S] binding partners in iron homeostasis.

    Science.gov (United States)

    Li, Haoran; Outten, Caryn E

    2012-06-05

    Monothiol glutaredoxins (Grxs) with a signature CGFS active site and BolA-like proteins have recently emerged as novel players in iron homeostasis. Elegant genetic and biochemical studies examining the functional and physical interactions of CGFS Grxs in the fungi Saccharomyces cerevisiae and Schizosaccharomyces pombe have unveiled their essential roles in intracellular iron signaling, iron trafficking, and the maturation of Fe-S cluster proteins. Biophysical and biochemical analyses of the [2Fe-2S] bridging interaction between CGFS Grxs and a BolA-like protein in S. cerevisiae provided the first molecular-level understanding of the iron regulation mechanism in this model eukaryote and established the ubiquitous CGFS Grxs and BolA-like proteins as novel Fe-S cluster-binding regulatory partners. Parallel studies focused on Escherichia coli and human homologues for CGFS Grxs and BolA-like proteins have supported the studies in yeast and provided additional clues about their involvement in cellular iron metabolism. Herein, we review recent progress in uncovering the cellular and molecular mechanisms by which CGFS Grxs and BolA-like proteins help regulate iron metabolism in both eukaryotic and prokaryotic organisms.

  5. Intravenous Iron Sucrose for Children With Iron Deficiency Anemia.

    Science.gov (United States)

    Kaneva, Kristiyana; Chow, Erika; Rosenfield, Cathy G; Kelly, Michael J

    2017-07-01

    Iron deficiency anemia (IDA) is the most common nutritional deficiency in children. Most children with IDA are treated with oral iron preparations. However, intravenous (IV) iron is an alternative for children with severe IDA who have difficulty in adhering to or absorbing oral iron. We sought to describe the safety and effectiveness of IV iron sucrose for treatment of IDA in children. Pharmacy records of children who received IV iron sucrose at a children's hospital between 2004 and 2014 were reviewed. Laboratory markers of anemia and iron studies were obtained and preinfusion and postinfusion values were compared. Records were also reviewed for adverse reactions. A total of 142 patients received IV iron sucrose over 10 years. The mean age was 11 years, 9 months. One patient of 142 developed cough and wheezing during the infusion. No other adverse events were found. IV iron sucrose resulted in a statistically significant and clinically meaningful increase in hemoglobin, mean corpuscular volume, serum iron, ferritin, and % iron saturation, with a corresponding decrease in total iron binding capacity. The use of IV iron sucrose in pediatric patients with IDA is safe and leads to a moderate increase in hemoglobin and substantial improvement in iron studies.

  6. High-capacity lithium-ion battery conversion cathodes based on iron fluoride nanowires and insights into the conversion mechanism.

    Science.gov (United States)

    Li, Linsen; Meng, Fei; Jin, Song

    2012-11-14

    The increasing demands from large-scale energy applications call for the development of lithium-ion battery (LIB) electrode materials with high energy density. Earth abundant conversion cathode material iron trifluoride (FeF(3)) has a high theoretical capacity (712 mAh g(-1)) and the potential to double the energy density of the current cathode material based on lithium cobalt oxide. Such promise has not been fulfilled due to the nonoptimal material properties and poor kinetics of the electrochemical conversion reactions. Here, we report for the first time a high-capacity LIB cathode that is based on networks of FeF(3) nanowires (NWs) made via an inexpensive and scalable synthesis. The FeF(3) NW cathode yielded a discharge capacity as high as 543 mAh g(-1) at the first cycle and retained a capacity of 223 mAh g(-1) after 50 cycles at room temperature under the current of 50 mA g(-1). Moreover, high-resolution transmission electron microscopy revealed the existence of continuous networks of Fe in the lithiated FeF(3) NWs after discharging, which is likely an important factor for the observed improved electrochemical performance. The loss of active material (FeF(3)) caused by the increasingly ineffective reconversion process during charging was found to be a major factor responsible for the capacity loss upon cycling. With the advantages of low cost, large quantity, and ease of processing, these FeF(3) NWs are not only promising battery cathode materials but also provide a convenient platform for fundamental studies and further improving conversion cathodes in general.

  7. Cu Binding to Iron Oxide-Organic Matter Coprecipitates in Solid and Dissolved Phases

    Science.gov (United States)

    Vadas, T. M.; Koenigsmark, F.

    2015-12-01

    Recent studies indicate that Cu is released from wetlands following storm events. Assymetrical field flow field fractionation (AF4) analyses as well as total and dissolved metal concentration measurements suggest iron oxide-organic matter complexes control Cu retention and release. Coprecipitation products of Fe oxide and organic matter were prepared under conditions similar to the wetland to assess Cu partitioning to and availability from solid phases that settle from solution as well as phases remaining suspended. Cu coprecipitation and sorption to organomineral precipitation solids formed at different Fe:organic carbon (OC) ratios were compared for net Cu removal and extractability. As more humic acid was present during precipitation of Fe, TEM images indicated smaller Fe oxide particles formed within an organic matrix as expected. In coprecipitation reactions, as the ratio of Fe:OC decreased, more Cu was removed from solution at pH 5.5 and below. However, in sorption reactions, there was an inhibition of Cu removal at low OC concentrations. As the pH increased from 5.5 to 7 and as solution phase OC concentration increased, more Cu remained dissolved in both coprecipitation and sorption reactions. The addition of Ca2+, glycine, histidine and citric acid or lowering the pH resulted in more extractable Cu from the coprecipitation compared with the sorption reactions. The variations in Cu extraction were likely due to a combination of a more amorphous structure in CPT products, and the relative abundance of available Fe oxide or OC binding sites. Suspended Fe oxide-organic matter coprecipitates were assessed using AF4 coupled to online TOC analysis and ICP-MS. In laboratory prepared samples, Cu was observed in a mixture of small 1-5 nm colloids of Fe oxide-organic matter precipitates, but the majority was observed in larger organic matter colloids and were not UV absorbing, suggesting more aliphatic carbon materials. In field samples, up to 60% of the dissolved Cu

  8. Ab initio design of Ca-decorated organic frameworks for high capacity molecular hydrogen storage with enhanced binding

    Science.gov (United States)

    Sun, Y. Y.; Lee, Kyuho; Kim, Yong-Hyun; Zhang, S. B.

    2009-07-01

    Ab initio calculations show that Ca can decorate organic linkers of metal-organic framework, MOF-5, with a binding energy of 1.25 eV. The Ca-decorated MOF-5 can store molecular hydrogen (H2) in both high gravimetric (4.6 wt %) and high volumetric (36 g/l) capacities. Even higher capacities (5.7 wt % and 45 g/l) can be obtained in a rationally designed covalent organic framework system, COF-α, with decorated Ca. Both density functional theory and second-order Møller-Plesset perturbation calculations show that the H2 binding in these systems is significantly stronger than the van der Waals interactions, which is required for H2 storage at near ambient conditions.

  9. Significance of tests of iron nutrition in pregnancy

    Science.gov (United States)

    Metz, J.; Turchetti, L.; Combrink, B.; Krawitz, S.

    1966-01-01

    Tests of iron and folate nutrition have been carried out in early pregnancy and at delivery in 63 Bantu females. Accepted normal values for serum iron, and percentage saturation of transferrin, but not for unsaturated iron-binding capacity, for non-pregnant subjects were found to apply equally well in pregnancy. Concomitant folate deficiency in early pregnancy did not render tests of iron deficiency less valid. The unsaturated iron-binding capacity, percentage saturation, and marrow iron stores in early pregnancy all showed a significant correlation with the haemoglobin value at term. Patients with normal marrow iron stores and a percentage saturation of transferrin of 20 or more at or before the 24th week are unlikely to become anaemic from iron deficiency during pregnancy. PMID:5909700

  10. HtaA is an iron-regulated hemin binding protein involved in the utilization of heme iron in Corynebacterium diphtheriae.

    Science.gov (United States)

    Allen, Courtni E; Schmitt, Michael P

    2009-04-01

    Many human pathogens, including Corynebacterium diphtheriae, the causative agent of diphtheria, use host compounds such as heme and hemoglobin as essential iron sources. In this study, we examined the Corynebacterium hmu hemin transport region, a genetic cluster that contains the hmuTUV genes encoding a previously described ABC-type hemin transporter and three additional genes, which we have designated htaA, htaB, and htaC. The hmu gene cluster is composed of three distinct transcriptional units. The htaA gene appears to be part of an iron- and DtxR-regulated operon that includes hmuTUV, while htaB and htaC are transcribed from unique DtxR-regulated promoters. Nonpolar deletion of either htaA or the hmuTUV genes resulted in a reduced ability to use hemin as an iron source, while deletion of htaB had no effect on hemin iron utilization in C. diphtheriae. A comparison of the predicted amino acid sequences of HtaA and HtaB showed that they share some sequence similarity, and both proteins contain leader sequences and putative C-terminal transmembrane regions. Protein localization studies with C. diphtheriae showed that HtaA is associated predominantly with the cell envelope when the organism is grown in minimal medium but is secreted during growth in nutrient-rich broth. HtaB and HmuT were detected primarily in the cytoplasmic membrane fraction regardless of the growth medium. Hemin binding studies demonstrated that HtaA and HtaB are able to bind hemin, suggesting that these proteins may function as cell surface hemin receptors in C. diphtheriae.

  11. Iron binding efficiency of polyphenols: Comparison of effect of ascorbic acid and ethylenediaminetetraacetic acid on catechol and galloyl groups.

    Science.gov (United States)

    Tamilmani, Poonkodi; Pandey, Mohan Chandra

    2016-04-15

    Dietary polyphenols are markedly studied for their antioxidant activity. They also have a negative impact on nutrition whereby they interfere with iron absorption. Common dietary polyphenols include: catechins, flavonols, flavanols, flavones, anthocyanins, proanthocyanidins and phenolic acids. Ascorbic acid (AA) and Ethylenediaminetetraacetic acid (EDTA) are commonly used to counter act this reaction and increase iron bioavailability. This study was aimed at determining the effect of AA and EDTA on the catechol or galloyl iron binding ability of pure phenolics, coffee and tea. Phenolic concentrations of 40, 80, 610, 240, 320, 400, 520 and 900 μg/ml were tested against six levels of AA and EDTA. These effects were studied in detail using Multivariate Analysis of Variance (MANOVA) with the hypothesis that there would be one or more mean differences between the ratio of enhancer and the different concentrations of samples tested. AA was found to be more efficient than EDTA in a way that lesser quantity is required for completely overcoming negative iron binding effects of polyphenols and similar samples.

  12. Analysis of Heme Iron Coordination in DGCR8: The Heme-Binding Component of the Microprocessor Complex.

    Science.gov (United States)

    Girvan, Hazel M; Bradley, Justin M; Cheesman, Myles R; Kincaid, James R; Liu, Yilin; Czarnecki, Kazimierz; Fisher, Karl; Leys, David; Rigby, Stephen E J; Munro, Andrew W

    2016-09-13

    DGCR8 is the RNA-binding partner of the nuclease Drosha. Their complex (the "Microprocessor") is essential for processing of long, primary microRNAs (pri-miRNAs) in the nucleus. Binding of heme to DGCR8 is essential for pri-miRNA processing. On the basis of the split Soret ultraviolet-visible (UV-vis) spectrum of ferric DGCR8, bis-thiolate sulfur (cysteinate, Cys(-)) heme iron coordination of DGCR8 heme iron was proposed. We have characterized DGCR8 heme ligation using the Δ276 DGCR8 variant and combined electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD), electron nuclear double resonance, resonance Raman, and electronic absorption spectroscopy. These studies indicate DGCR8 bis-Cys heme iron ligation, with conversion from bis-thiolate (Cys(-)/Cys(-)) axial coordination in ferric DGCR8 to bis-thiol (CysH/CysH) coordination in ferrous DGCR8. Pri-miRNA binding does not perturb ferric DGCR8's optical spectrum, consistent with the axial ligand environment being separated from the substrate-binding site. UV-vis absorption spectra of the Fe(II) and Fe(II)-CO forms indicate discrete species exhibiting peaks with absorption coefficients substantially larger than those for ferric DGCR8 and that previously reported for a ferrous form of DGCR8. Electron-nuclear double resonance spectroscopy data exclude histidine or water as axial ligands for ferric DGCR8 and favor bis-thiolate coordination in this form. UV-vis MCD and near-infrared MCD provide data consistent with this conclusion. UV-vis MCD data for ferrous DGCR8 reveal features consistent with bis-thiol heme iron coordination, and resonance Raman data for the ferrous-CO form are consistent with a thiol ligand trans to the CO. These studies support retention of DGCR8 cysteine coordination upon reduction, a conclusion distinct from those of previous studies of a different ferrous DGCR8 isoform.

  13. Characteristic of the nutritive value of the protein from rye coryopses. II. Evaluation of rye grain protein quality by Dye-Binding Capacity method

    OpenAIRE

    K. Kubiczek; G. Chojnacki

    2015-01-01

    The usefulness for breeding porposes of the azosulphonic dye-binding capacity (DBC method) by proteins for large scale screening nutritive value characteristic of rye grain protein was studied. It was established that binding capacity of dye by rye grain protein is positively, significantly correlated with protein nutritive value indicators, e.g. CS (Chemical Score). The amounts of the binded dye by 1 g of milled rye grains were positively, significantly correlated with "useful" protein conte...

  14. Lateral load-carrying capacity analyses of composite shear walls with double steel plates and filled concrete with binding bars

    Institute of Scientific and Technical Information of China (English)

    周德源; 刘凌飞; 朱立猛

    2016-01-01

    A method is developed to predict the lateral load-carrying capacity of composite shear walls with double steel plates and filled concrete with binding bars (SCBs). Nonlinear finite element models of SCBs were established by using the finite element tool, Abaqus. Tie constraints were used to connect the binding bars and the steel plates. Surface-to-surface contact provided by the Abaqus was used to simulate the interaction between the steel plate and the core concrete. The established models could predict the lateral load-carrying capacity of SCBs with a reasonable degree of accuracy. A calculation method was developed by superposition principle to predict the lateral load-carrying capacity of SCBs for the engineering application. The concrete confined by steel plates and binding bars is under multi-axial compression; therefore, its shear strength was calculated by using the Guo-Wang concrete failure criterion. The shear strength of the steel plates of SCBs was calculated by using the von Mises yielding criterion without considering buckling. Results of the developed method are in good agreement with the testing and finite element results.

  15. Iron-nucleated folding of a metalloprotein in high urea: resolution of metal binding and protein folding events.

    Science.gov (United States)

    Morleo, Anna; Bonomi, Francesco; Iametti, Stefania; Huang, Victor W; Kurtz, Donald M

    2010-08-10

    Addition of iron salts to chaotrope-denatured aporubredoxin (apoRd) leads to nearly quantitative recovery of its single Fe(SCys)(4) site and native protein structure without significant dilution of the chaotrope. This "high-chaotrope" approach was used to examine iron binding and protein folding events using stopped-flow UV-vis absorption and CD spectroscopies. With a 100-fold molar excess of ferrous iron over denatured apoRd maintained in 5 M urea, the folded holoFe(III)Rd structure was recovered in >90% yield with a t(1/2) of Ser iron ligand variants support formation of an unfolded-Fe(SCys)(3) complex between steps 1 and 2, which we propose is the key nucleation event that pulls together distal regions of the protein chain. These results show that folding of chaotrope-denatured apoRd is iron-nucleated and driven by extraordinarily rapid formation of the Fe(SCys)(4) site from an essentially random coil apoprotein. This high-chaotrope, multispectroscopy approach could clarify folding pathways of other [M(SCys)(3)]- or [M(SCys)(4)]-containing proteins.

  16. Evaluation of the arsenic binding capacity of plant proteins under conditions of protein extraction for gel electrophoretic analysis.

    Science.gov (United States)

    Schmidt, Anne-Christine; Steier, Sandra; Otto, Matthias

    2009-03-15

    As prerequisite for the investigation of arsenic-binding proteins in plants, the general influence of different extraction parameters on the binding behaviour of arsenic to the plant protein pool was investigated. The concentration of the extraction buffer affected the extraction yield both for proteins and for arsenic revealing an optimal buffer concentration of 5mM Tris/HCl, pH 8. The addition of 1 or 2% (w/v) SDS to the extraction buffer produced a two- to threefold enhancement of the total protein extraction yield but strongly suppressed the simultaneous extraction of arsenic from 80+/-8% extraction yield obtained without SDS to 48+/-2% in presence of 2% (w/v) SDS. The arsenic binding capacity of the protein fraction obtained after extraction with Tris buffer and protein precipitation by trichloroacetic acid in acetone was estimated to be 1.4+/-0.6% independently on the original spiking concentration of arsenic provided in the form of monomethylarsonate to the extracts. Due to the low total protein concentrations of the plant extracts that varied in the range from 75 to 412 microgmL(-1) depending on the extraction parameters, high arsenic concentrations of 263-1001 mg (kgproteinmass)(-1) resulted for spiking concentrations of 10 mgAsL(-1). The optimized protein isolation procedure was applied to plants grown under arsenic exposure and revealed a similar arsenic binding capacity as for the spiked protein extracts.

  17. Protein imprinted ionic liquid polymer on the surface of multiwall carbon nanotubes with high binding capacity for lysozyme.

    Science.gov (United States)

    Yuan, Shifang; Deng, Qiliang; Fang, Guozhen; Wu, Jianhua; Li, Wangwang; Wang, Shuo

    2014-06-01

    In this research, ionic liquid as functional monomer to prepare molecularly imprinted polymers for protein recognition was for the first time demonstrated, in which, 1-vinyl-3-butylimidazolium chloride was selected as functional monomer, acrylamide as co-functional monomer and lysozyme (Lyz) as template protein to synthesize imprinted polymers on the surface of multiwall carbon nanotubes in aqueous medium. The results indicated that ionic liquid was helpful to improve binding capacity of imprinted polymers, which had a maximum binding capacity of 763.36 mg/g in the optimum adsorption conditions. The prepared imprinted polymers had a fast adsorption rate and a much higher adsorption capacity than the corresponding non-imprinted polymers, with the difference in adsorption capacity up to 258.31 mg/g. The obtained polymer was evaluated by Lyz, bovine serum albumin (BSA), bovine hemoglobin (BHb), equine myoglobin (MB) and cytochrome c (Cyt c). The selectivity factor (β) for Lyz/BSA, Lyz/Mb, Lyz/BHb, and Lyz/Cyt c were 7.17, 2.12, 1.76 and 1.57, respectively, indicating the imprinted polymers had a good selectivity. Easy preparation of the imprinted polymers as well as high ability and selectivity to adsorb template proteins makes this polymer attractive and broadly applicable in biomacromolecular separation, biotechnology and sensors.

  18. Different behaviours in phytoremediation capacity of two heavy metal tolerant poplar clones in relation to iron and other trace elements.

    Science.gov (United States)

    Baldantoni, Daniela; Cicatelli, Angela; Bellino, Alessandro; Castiglione, Stefano

    2014-12-15

    Plant biodiversity and intra-population genetic variability have not yet been properly exploited in the framework of phytoremediation and soil reclamation. For this reason, iron and other metal accumulation capacity of two Cu and Zn tolerant poplar clones, namely AL22 (Populus alba L.) and N12 (Populus nigra L.), was investigated in a pot experiment. Cuttings of the two clones were planted in iron rich soil collected from an urban-industrial area. Concentrations of Cd, Cu, Fe, Pb and Zn were analysed in leaves (at different times), as well as in stems and in roots (at the end of the experiment), both in control plants and in plants grown on a soil whose Fe availability was artificially enhanced. Results showed that Cd and Zn were preferentially accumulated in leaves, whereas Cu, Fe and Pb were mainly accumulated in roots. The main differences in metal accumulation between clones were related to Cd (about tenfold higher concentrations in N12) and Cu (higher concentrations in AL22). Once soil Fe availability was enhanced, the uptake and accumulation of all metals declined, with the exception of Fe at the first sampling time in AL22 leaves. The different behaviour of the two poplar clones suggests that a thoughtful choice should be made for their use in relation to soil heavy metal remediation.

  19. Iron decorated - functionalized MOF for high-capacity hydrogen storage: First-principles calculations

    Science.gov (United States)

    Cha, Moon-Hyun; Ihm, Jisoon

    2011-03-01

    We perform electronic structure calculations for the Fe-decorated, OH-functionalized isoreticular metal organic framework 16 (IRMOF16) to investigate the hydrogen storage capacity. Because of the relatively strong Kubas interaction between Fe and H2 , hydrogen molecule can be adsorbed on the proposed MOF even at room temperature. The reversibly usable storage capacity under ambient conditions reaches 6.0 wt%. Fe has a much lower oxidation tendency than other metals (e.g., Ti, Ca, or Li) used for decorating backbone structures and therefore far more convenient in practical implementation. We also find that the spin flip, which comes from the competition between exchange field splitting and ligand field splitting, plays a significant role in the interaction between Fe and H2 .

  20. Stability of the octameric structure affects plasminogen-binding capacity of streptococcal enolase.

    Directory of Open Access Journals (Sweden)

    Amanda J Cork

    Full Text Available Group A Streptococcus (GAS is a human pathogen that has the potential to cause invasive disease by binding and activating human plasmin(ogen. Streptococcal surface enolase (SEN is an octameric α-enolase that is localized at the GAS cell surface. In addition to its glycolytic role inside the cell, SEN functions as a receptor for plasmin(ogen on the bacterial surface, but the understanding of the molecular basis of plasmin(ogen binding is limited. In this study, we determined the crystal and solution structures of GAS SEN and characterized the increased plasminogen binding by two SEN mutants. The plasminogen binding ability of SENK312A and SENK362A is ~2- and ~3.4-fold greater than for the wild-type protein. A combination of thermal stability assays, native mass spectrometry and X-ray crystallography approaches shows that increased plasminogen binding ability correlates with decreased stability of the octamer. We propose that decreased stability of the octameric structure facilitates the access of plasmin(ogen to its binding sites, leading to more efficient plasmin(ogen binding and activation.

  1. Binding of heavy metal ions in aggregates of microbial cells, EPS and biogenic iron minerals measured in-situ using metal- and glycoconjugates-specific fluorophores

    Science.gov (United States)

    Hao, Likai; Guo, Yuan; Byrne, James M.; Zeitvogel, Fabian; Schmid, Gregor; Ingino, Pablo; Li, Jianli; Neu, Thomas R.; Swanner, Elizabeth D.; Kappler, Andreas; Obst, Martin

    2016-05-01

    Aggregates consisting of bacterial cells, extracellular polymeric substances (EPS) and Fe(III) minerals formed by Fe(II)-oxidizing bacteria are common at bulk or microscale chemical interfaces where Fe cycling occurs. The high sorption capacity and binding capacity of cells, EPS, and minerals controls the mobility and fate of heavy metals. However, it remains unclear to which of these component(s) the metals will bind in complex aggregates. To clarify this question, the present study focuses on 3D mapping of heavy metals sorbed to cells, glycoconjugates that comprise the majority of EPS constituents, and Fe(III) mineral aggregates formed by the phototrophic Fe(II)-oxidizing bacteria Rhodobacter ferrooxidans SW2 using confocal laser scanning microscopy (CLSM) in combination with metal- and glycoconjugates-specific fluorophores. The present study evaluated the influence of glycoconjugates, microbial cell surfaces, and (biogenic) Fe(III) minerals, and the availability of ferrous and ferric iron on heavy metal sorption. Analyses in this study provide detailed knowledge on the spatial distribution of metal ions in the aggregates at the sub-μm scale, which is essential to understand the underlying mechanisms of microbe-mineral-metal interactions. The heavy metals (Au3+, Cd2+, Cr3+, CrO42-, Cu2+, Hg2+, Ni2+, Pd2+, tributyltin (TBT) and Zn2+) were found mainly sorbed to cell surfaces, present within the glycoconjugates matrix, and bound to the mineral surfaces, but not incorporated into the biogenic Fe(III) minerals. Statistical analysis revealed that all ten heavy metals tested showed relatively similar sorption behavior that was affected by the presence of sorbed ferrous and ferric iron. Results in this study showed that in addition to the mineral surfaces, both bacterial cell surfaces and the glycoconjugates provided most of sorption sites for heavy metals. Simultaneously, ferrous and ferric iron ions competed with the heavy metals for sorption sites on the organic

  2. Antioxidant and iron-binding properties of curcumin, capsaicin, and S-allylcysteine reduce oxidative stress in rat brain homogenate.

    Science.gov (United States)

    Dairam, Amichand; Fogel, Ronen; Daya, Santy; Limson, Janice L

    2008-05-14

    Research demonstrates that antioxidants and metal chelators may be of beneficial use in the treatment of neurodegenerative diseases, such as Alzheimer's disease (AD). This study investigated the antioxidant and metal-binding properties of curcumin, capsaicin, and S-allylcysteine, which are major components found in commonly used dietary spice ingredients turmeric, chilli, and garlic, respectively. The DPPH assay demonstrates that these compounds readily scavenge free radicals. These compounds significantly curtail iron- (Fe2+) and quinolinic acid (QA)-induced lipid peroxidation and potently scavenge the superoxide anion generated by 1 mM cyanide in rat brain homogenate. The ferrozine assay was used to measure the extent of Fe2+ chelation, and electrochemistry was employed to measure the Fe3+ binding activity of curcumin, capsaicin, and S-allylcysteine. Both assays demonstrate that these compounds bind Fe2+ and Fe3+ and prevent the redox cycling of iron, suggesting that this may be an additional method through which these agents reduce Fe2+-induced lipid peroxidation. This study demonstrates the antioxidant and metal-binding properties of these spice ingredients, and it is hereby postulate that these compounds have important implications in the prevention or treatment of neurodegenerative diseases such as AD.

  3. Calcium-binding capacity of centrin2 is required for linear POC5 assembly but not for nucleotide excision repair.

    Directory of Open Access Journals (Sweden)

    Tiago J Dantas

    Full Text Available Centrosomes, the principal microtubule-organising centres in animal cells, contain centrins, small, conserved calcium-binding proteins unique to eukaryotes. Centrin2 binds to xeroderma pigmentosum group C protein (XPC, stabilising it, and its presence slightly increases nucleotide excision repair (NER activity in vitro. In previous work, we deleted all three centrin isoforms present in chicken DT40 cells and observed delayed repair of UV-induced DNA lesions, but no centrosome abnormalities. Here, we explore how centrin2 controls NER. In the centrin null cells, we expressed centrin2 mutants that cannot bind calcium or that lack sites for phosphorylation by regulatory kinases. Expression of any of these mutants restored the UV sensitivity of centrin null cells to normal as effectively as expression of wild-type centrin. However, calcium-binding-deficient and T118A mutants showed greatly compromised localisation to centrosomes. XPC recruitment to laser-induced UV-like lesions was only slightly slower in centrin-deficient cells than in controls, and levels of XPC and its partner HRAD23B were unaffected by centrin deficiency. Interestingly, we found that overexpression of the centrin interactor POC5 leads to the assembly of linear, centrin-dependent structures that recruit other centrosomal proteins such as PCM-1 and NEDD1. Together, these observations suggest that assembly of centrins into complex structures requires calcium binding capacity, but that such assembly is not required for centrin activity in NER.

  4. Purification and characterisation of a glutamic acid-containing peptide with calcium-binding capacity from whey protein hydrolysate.

    Science.gov (United States)

    Huang, Shun-Li; Zhao, Li-Na; Cai, Xixi; Wang, Shao-Yun; Huang, Yi-Fan; Hong, Jing; Rao, Ping-Fan

    2015-02-01

    The bioavailability of dietary ionised calcium is affected by intestinal basic environment. Calcium-binding peptides can form complexes with calcium to improve its absorption and bioavailability. The aim of this study was focused on isolation and characterisation of a calcium-binding peptide from whey protein hydrolysates. Whey protein was hydrolysed using Flavourzyme and Protamex with substrate to enzyme ratio of 25:1 (w/w) at 49 °C for 7 h. The calcium-binding peptide was isolated by DEAE anion-exchange chromatography, Sephadex G-25 gel filtration and reversed phase high-performance liquid chromatography (RP-HPLC). A purified peptide of molecular mass 204 Da with strong calcium binding ability was identified on chromatography/electrospray ionisation (LC/ESI) tandem mass spectrum to be Glu-Gly (EG) after analysis and alignment in database. The calcium binding capacity of EG reached 67·81 μg/mg, and the amount increased by 95% compared with whey protein hydrolysate complex. The UV and infrared spectrometer analysis demonstrated that the principal sites of calcium-binding corresponded to the carboxyl groups and carbonyl groups of glutamic acid. In addition, the amino group and peptide amino are also the related groups in the interaction between EG and calcium ion. Meanwhile, the sequestered calcium percentage experiment has proved that EG-Ca is significantly more stable than CaCl2 in human gastrointestinal tract in vitro. The findings suggest that the purified dipeptide has the potential to be used as ion-binding ingredient in dietary supplements.

  5. Oxidizing capacity of periodate activated with iron-based bimetallic nanoparticles.

    Science.gov (United States)

    Lee, Hongshin; Yoo, Ha-Young; Choi, Jihyun; Nam, In-Hyun; Lee, Sanghyup; Lee, Seunghak; Kim, Jae-Hong; Lee, Changha; Lee, Jaesang

    2014-07-15

    Nanosized zerovalent iron (nFe0) loaded with a secondary metal such as Ni or Cu on its surface was demonstrated to effectively activate periodate (IO4-) and degrade selected organic compounds at neutral pH. The degradation was accompanied by a stoichiometric conversion of IO4- to iodate (IO3-). nFe0 without bimetallic loading led to similar IO4- reduction but no organic degradation, suggesting the production of reactive iodine intermediate only when IO4- is activated by bimetallic nFe0 (e.g., nFe0-Ni and nFe0-Cu). The organic degradation kinetics in the nFe0-Ni(or Cu)/IO4- system was substrate dependent: 4-chlorophenol, phenol, and bisphenol A were effectively degraded, whereas little or no degradation was observed with benzoic acid, carbamazepine, and 2,4,6-trichlorophenol. The substrate specificity, further confirmed by little kinetic inhibition with background organic matter, implies the selective nature of oxidant in the nFe0-Ni(or Cu)/IO4- system. The comparison with the photoactivated IO4- system, in which iodyl radical (IO3•) is a predominant oxidant in the presence of methanol, suggests IO3• also as primary oxidant in the nFe0-Ni(or Cu)/IO4- system.

  6. A Synthetic Peptide with the Putative Iron Binding Motif of Amyloid Precursor Protein (APP) Does Not Catalytically Oxidize Iron

    NARCIS (Netherlands)

    Honarmand Ebrahimi, K.; Hagedoorn, P.L.; Hagen, W.R.

    2012-01-01

    The β-amyloid precursor protein (APP), which is a key player in Alzheimer's disease, was recently reported to possess an Fe(II) binding site within its E2 domain which exhibits ferroxidase activity [Duce et al. 2010, Cell 142: 857]. The putative ligands of this site were compared to those in the fer

  7. Construction of an S-layer protein exhibiting modified self-assembling properties and enhanced metal binding capacities.

    Science.gov (United States)

    Pollmann, Katrin; Matys, Sabine

    2007-07-01

    The functional S-layer protein gene slfB of the uranium mining waste pile isolate Bacillus sphaericus JG-A12 was cloned as a polymerase chain reaction product into the expression vector pET Lic/Ek 30 and heterologously expressed in Escherichia coli Bl21(DE3). The addition of His tags to the N and C termini enabled the purification of the recombinant protein by Ni-chelating chromatography. The Ni binding capacity of the His-tagged recombinant S-layer protein was compared with that of the wild-type S layer. The inductively coupled plasma mass spectrometry analyses demonstrate a significantly enhanced Ni binding capability of the recombinant protein. In addition, the self-assembling properties of the purified modified S-layer proteins were studied by light microscopy and scanning electron microscopy. Whereas the wild-type S-layer proteins re-assembled into regular cylindric structures, the recombinant S-layer proteins reassembled into regular sheets that formed globular agglomerating structures. The nanoporous structure of the protein meshwork, together with its enhanced Ni binding capacity, makes the recombinant S-layer attractive as a novel self-assembling biological template for the fabrication of metal nanoclusters and construction of nanomaterials that are of technical interest.

  8. Conformational changes in Bcl-2 pro-survival proteins determine their capacity to bind ligands.

    Science.gov (United States)

    Lee, Erinna F; Czabotar, Peter E; Yang, Hong; Sleebs, Brad E; Lessene, Guillaume; Colman, Peter M; Smith, Brian J; Fairlie, W Douglas

    2009-10-30

    Antagonists of anti-apoptotic Bcl-2 family members hold promise as cancer therapeutics. Apoptosis is triggered when a peptide containing a BH3 motif or a small molecule BH3 peptidomimetic, such as ABT 737, binds to the relevant Bcl-2 family members. ABT-737 is an antagonist of Bcl-2, Bcl-x(L), and Bcl-w but not of Mcl-1. Here we describe new structures of mutant BH3 peptides bound to Bcl-x(L) and Mcl-1. These structures suggested a rationale for the failure of ABT-737 to bind Mcl-1, but a designed variant of ABT-737 failed to acquire binding affinity for Mcl-1. Rather, it was selective for Bcl-x(L), a result attributable in part to significant backbone refolding and movements of helical segments in its ligand binding site. To date there are few reported crystal structures of organic ligands in complex with their pro-survival protein targets. Our structure of this new organic ligand provided insights into the structural transitions that occur within the BH3 binding groove, highlighting significant differences in the structural properties of members of the Bcl-2 pro-survival protein family. Such differences are likely to influence and be important in the quest for compounds capable of selectively antagonizing the different family members.

  9. Soluble Fiber with High Water-Binding Capacity, Swelling Capacity, and Fermentability Reduces Food Intake by Promoting Satiety Rather Than Satiation in Rats

    Science.gov (United States)

    Tan, Chengquan; Wei, Hongkui; Zhao, Xichen; Xu, Chuanhui; Zhou, Yuanfei; Peng, Jian

    2016-01-01

    To understand whether soluble fiber (SF) with high water-binding capacity (WBC), swelling capacity (SC) and fermentability reduces food intake and whether it does so by promoting satiety or satiation or both, we investigated the effects of different SFs with these properties on the food intake in rats. Thirty-two male Sprague-Dawley rats were randomized to four equal groups and fed the control diet or diet containing 2% konjac flour (KF), pregelatinized waxy maize starch (PWMS) plus guar gum (PG), and PWMS starch plus xanthan gum (PX) for three weeks, with the measured values of SF, WBC, and SC in the four diets following the order of PG > KF > PX > control. Food intake, body weight, meal pattern, behavioral satiety sequence, and short-chain fatty acids (SCFAs) in cecal content were evaluated. KF and PG groups reduced the food intake, mainly due to the decreased feeding behavior and increased satiety, as indicated by decreased meal numbers and increased inter-meal intervals. Additionally, KF and PG groups increased concentrations of acetate acid, propionate acid, and SCFAs in the cecal contents. Our results indicate that SF with high WBC, SC, and fermentability reduces food intake—probably by promoting a feeling of satiety in rats to decrease their feeding behavior. PMID:27706095

  10. Soluble Fiber with High Water-Binding Capacity, Swelling Capacity, and Fermentability Reduces Food Intake by Promoting Satiety Rather Than Satiation in Rats.

    Science.gov (United States)

    Tan, Chengquan; Wei, Hongkui; Zhao, Xichen; Xu, Chuanhui; Zhou, Yuanfei; Peng, Jian

    2016-10-02

    To understand whether soluble fiber (SF) with high water-binding capacity (WBC), swelling capacity (SC) and fermentability reduces food intake and whether it does so by promoting satiety or satiation or both, we investigated the effects of different SFs with these properties on the food intake in rats. Thirty-two male Sprague-Dawley rats were randomized to four equal groups and fed the control diet or diet containing 2% konjac flour (KF), pregelatinized waxy maize starch (PWMS) plus guar gum (PG), and PWMS starch plus xanthan gum (PX) for three weeks, with the measured values of SF, WBC, and SC in the four diets following the order of PG > KF > PX > control. Food intake, body weight, meal pattern, behavioral satiety sequence, and short-chain fatty acids (SCFAs) in cecal content were evaluated. KF and PG groups reduced the food intake, mainly due to the decreased feeding behavior and increased satiety, as indicated by decreased meal numbers and increased inter-meal intervals. Additionally, KF and PG groups increased concentrations of acetate acid, propionate acid, and SCFAs in the cecal contents. Our results indicate that SF with high WBC, SC, and fermentability reduces food intake-probably by promoting a feeling of satiety in rats to decrease their feeding behavior.

  11. High-intensity ultrasonication as a way to prepare graphene/amorphous iron oxyhydroxide hybrid electrode with high capacity in lithium battery.

    Science.gov (United States)

    González, José R; Menéndez, Rosa; Alcántara, Ricardo; Nacimiento, Francisco; Tirado, José L; Zhecheva, Ekaterina; Stoyanova, Radostina

    2015-05-01

    The preparation of graphene/iron oxyhydroxide hybrid electrode material with very homogeneous distribution and close contact of graphene and amorphous iron oxyhydroxide nanoparticles has been achieved by using high-intensity ultrasonication. Due to the negative charge of the graphene surface, iron ions are attracted toward the surface of dispersed graphene, according to the zeta potential measurements. The anchoring of the FeO(OH) particles to the graphene layers has been revealed by using mainly TEM, XPS and EPR. TEM observations show that the size of the iron oxide particles is about 4 nm. The ultrasonication treatment is the key parameter to achieve small particle size in these graphene/iron oxyhydroxide hybrid materials. The electrochemical behavior of composite graphene/amorphous iron oxyhydroxide prepared by using high-intensity ultrasonication is outstanding in terms of gravimetric capacity and cycling stability, particularly when metallic foam is used as both the substrate and current collector. The XRD-amorphous character of iron oxyhydroxide in the hybrid electrode material and the small particle size contribute to achieve the improved electrochemical performance.

  12. Capacity of intact proteins to bind to MHC class II molecules

    DEFF Research Database (Denmark)

    Sette, A; Adorini, L; Colon, S M

    1989-01-01

    observations that some T cells can recognize denatured antigens without a further processing requirement. Moreover, a striking correlation was observed between the in vitro binding pattern of denatured proteins and the pattern of restriction of T cell responses elicited by immunization with the native antigen...

  13. Effect of crosslink density on the water-binding capacity of whey protein microparticles

    NARCIS (Netherlands)

    Peters, J.P.C.M.; Luyten, H.; Alting, A.C.; Boom, R.M.; Goot, van der A.J.

    2015-01-01

    The ability of whey protein microparticles (MPs) to bind water and consequently to swell is, amongst others, determined by the crosslink density of the MPs. The Flory-Rehner model states that a decrease in crosslink density should lead to an increased swelling of the MPs. Decreasing the crosslink

  14. Techno-functional properties and in vitro bile acid-binding capacities of tamarillo (Solanum betaceum Cav.) hydrocolloids.

    Science.gov (United States)

    Gannasin, Sri Puvanesvari; Adzahan, Noranizan Mohd; Mustafa, Shuhaimi; Muhammad, Kharidah

    2016-04-01

    Hydrocolloids were extracted from seed mucilage and the pulp fractions from red tamarillo (Solanum betaceum Cav.) mesocarp, and characterisation of their techno-functional properties and in vitro bile acid-binding capacities was performed. The seed mucilage hydrocolloids that were extracted, using either 1% citric acid (THC) or water (THW), had a good foaming capacity (32-36%), whereas the pulp hydrocolloids that were extracted, using 72% ethanol (THE) or 20mM HEPES buffer (THH), had no foaming capacity. The pulp hydrocolloid, however, possessed high oil-holding and water-holding capacities in the range of 3.3-3.6 g oil/g dry sample and 25-27 g water/g dry sample, respectively. This enabled the pulp hydrocolloid to entrap more bile acids (35-38% at a hydrocolloid concentration of 2%) in its gelatinous network in comparison to commercial oat fibre and other hydrocolloids studied. The exceptional emulsifying properties (80-96%) of both hydrocolloids suggest their potential applications as food emulsifiers and bile acid binders.

  15. Yerba mate (Ilex paraguariensis St. Hill.)-based beverages: How successive extraction influences the extract composition and its capacity to chelate iron and scavenge free radicals.

    Science.gov (United States)

    Colpo, Ana C; Rosa, Hemerson; Lima, Maria Eduarda; Pazzini, Camila Eliza F; de Camargo, Vanessa B; Bassante, Felipa E M; Puntel, Robson; Ávila, Daiana Silva; Mendez, Andreas; Folmer, Vanderlei

    2016-10-15

    Chimarrão or mate is a popular beverage from South America that is drank with successive infusions. Although yerba mate extracts have been widely studied, few studies have described the extract contents in beverages. Using yerba mate samples from Brazil, Argentina, and Uruguay, we examined the extract chromatographic profiles, total polyphenol content and their capacities to chelate iron. In addition, we analyzed antioxidant activity by examining the ability of the extracts to scavenge DPPH and NO. Our results showed that the amount of extracted compound was highest in yerba mate extract from Uruguay, followed by Argentina, then Brazil. Herbs from all three areas had a significant capacity to inhibit DPPH and NO free radicals. The Brazilian and Uruguayan herbs had an 80% iron chelation capacity (p<0.001), while the iron chelation capacity of the Argentinean herb was lower but still significant (p⩽0.05). We conclude that the compound concentration decreases with successive extractions, while the antioxidant capacity is maintained at significant levels.

  16. Iron mineralogy and uranium-binding environment in the rhizosphere of a wetland soil

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset contains two XRF images of iron and uranium distribution on plant roots and a database of XANES data used to produce XANES spectra figure for Figure 7 in...

  17. Novel Peptide with Specific Calcium-Binding Capacity from Schizochytrium sp. Protein Hydrolysates and Calcium Bioavailability in Caco-2 Cells.

    Science.gov (United States)

    Cai, Xixi; Lin, Jiaping; Wang, Shaoyun

    2016-12-27

    Peptide-calcium can probably be a suitable supplement to improve calcium absorption in the human body. In this study, a specific peptide Phe-Tyr (FY) with calcium-binding capacity was purified from Schizochytrium sp. protein hydrolysates through gel filtration chromatography and reversed phase HPLC. The calcium-binding capacity of FY reached 128.77 ± 2.57 μg/mg. Results of ultraviolet spectroscopy, fluorescence spectroscopy, and infrared spectroscopy showed that carboxyl groups, amino groups, and amido groups were the major chelating sites. FY-Ca exhibited excellent thermal stability and solubility, which were beneficial to be absorbed and transported in the basic intestinal tract of the human body. Moreover, the calcium bioavailability in Caco-2 cells showed that FY-Ca could enhance calcium uptake efficiency by more than three times when compared with CaCl₂, and protect calcium ions against dietary inhibitors, such as tannic acid, oxalate, phytate, and Zn(2+). Our findings further the progress of algae-based peptide-calcium, suggesting that FY-Ca has the potential to be developed as functionally nutraceutical additives.

  18. Novel Peptide with Specific Calcium-Binding Capacity from Schizochytrium sp. Protein Hydrolysates and Calcium Bioavailability in Caco-2 Cells

    Science.gov (United States)

    Cai, Xixi; Lin, Jiaping; Wang, Shaoyun

    2016-01-01

    Peptide-calcium can probably be a suitable supplement to improve calcium absorption in the human body. In this study, a specific peptide Phe-Tyr (FY) with calcium-binding capacity was purified from Schizochytrium sp. protein hydrolysates through gel filtration chromatography and reversed phase HPLC. The calcium-binding capacity of FY reached 128.77 ± 2.57 μg/mg. Results of ultraviolet spectroscopy, fluorescence spectroscopy, and infrared spectroscopy showed that carboxyl groups, amino groups, and amido groups were the major chelating sites. FY-Ca exhibited excellent thermal stability and solubility, which were beneficial to be absorbed and transported in the basic intestinal tract of the human body. Moreover, the calcium bioavailability in Caco-2 cells showed that FY-Ca could enhance calcium uptake efficiency by more than three times when compared with CaCl2, and protect calcium ions against dietary inhibitors, such as tannic acid, oxalate, phytate, and Zn2+. Our findings further the progress of algae-based peptide-calcium, suggesting that FY-Ca has the potential to be developed as functionally nutraceutical additives. PMID:28036002

  19. Novel Peptide with Specific Calcium-Binding Capacity from Schizochytrium sp. Protein Hydrolysates and Calcium Bioavailability in Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Xixi Cai

    2016-12-01

    Full Text Available Peptide-calcium can probably be a suitable supplement to improve calcium absorption in the human body. In this study, a specific peptide Phe-Tyr (FY with calcium-binding capacity was purified from Schizochytrium sp. protein hydrolysates through gel filtration chromatography and reversed phase HPLC. The calcium-binding capacity of FY reached 128.77 ± 2.57 μg/mg. Results of ultraviolet spectroscopy, fluorescence spectroscopy, and infrared spectroscopy showed that carboxyl groups, amino groups, and amido groups were the major chelating sites. FY-Ca exhibited excellent thermal stability and solubility, which were beneficial to be absorbed and transported in the basic intestinal tract of the human body. Moreover, the calcium bioavailability in Caco-2 cells showed that FY-Ca could enhance calcium uptake efficiency by more than three times when compared with CaCl2, and protect calcium ions against dietary inhibitors, such as tannic acid, oxalate, phytate, and Zn2+. Our findings further the progress of algae-based peptide-calcium, suggesting that FY-Ca has the potential to be developed as functionally nutraceutical additives.

  20. Sequential Proton Loss Electron Transfer in Deactivation of Iron(IV) Binding Protein by Tyrosine Based Food Components

    DEFF Research Database (Denmark)

    Tang, Ning; Skibsted, Leif Horsfelt

    2017-01-01

    The iron(IV) binding protein ferrylmyoglobin, MbFe(IV)=O, was found to be reduced by tyrosine based food components in aqueous solution through a sequential proton loss electron transfer reaction mechanism without binding to the protein as confirmed by isothermal titration calorimetry. Dopamine...... by protonation of ferrylmyoglobin and facilitated proton transfer at acidic conditions. Enthalpy-entropy compensation effects were observed for the activation parameters (ΔH† and ΔS†), indicating the common reaction mechanism. Moreover, principal component analysis combined with heat map were performed...... to understand the relationship between density functional theory calculated molecular descriptors and kinetic data, which was further modeled by partial least squares for quantitative structure-activity relationship analysis. In addition, a three tyrosine residue containing protein, lysozyme, was also found...

  1. MetalPredator: a web server to predict iron-sulfur cluster binding proteomes.

    Science.gov (United States)

    Valasatava, Yana; Rosato, Antonio; Banci, Lucia; Andreini, Claudia

    2016-09-15

    The prediction of the iron-sulfur proteome is highly desirable for biomedical and biological research but a freely available tool to predict iron-sulfur proteins has not been developed yet. We developed a web server to predict iron-sulfur proteins from protein sequence(s). This tool, called MetalPredator, is able to process complete proteomes rapidly with high recall and precision. The web server is freely available at: http://metalweb.cerm.unifi.it/tools/metalpredator/ andreini@cerm.unifi.it Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. A Specific Peptide with Calcium-Binding Capacity from Defatted Schizochytrium sp. Protein Hydrolysates and the Molecular Properties

    Directory of Open Access Journals (Sweden)

    Xixi Cai

    2017-03-01

    Full Text Available Marine microorganisms have been proposed as a new kind of protein source. Efforts are needed in order to transform the protein-rich biological wastes left after lipid extraction into value-added bio-products. Thus, the utilization of protein recovered from defatted Schizochytrium sp. by-products presents an opportunity. A specific peptide Tyr-Leu (YL with calcium-binding capacity was purified from defatted Schizochytrium sp. protein hydrolysates through gel filtration chromatography and RP-HPLC. The calcium-binding activity of YL reached 126.34 ± 3.40 μg/mg. The calcium-binding mechanism was investigated through ultraviolet, fluorescence and infrared spectroscopy. The results showed that calcium ions could form dative bonds with carboxyl oxygen atoms and amino nitrogen atoms as well as the nitrogen and oxygen atoms of amide bonds. YL-Ca exhibited excellent thermal stability and solubility, which was beneficial for its absorption and transport in the basic intestinal tract of the human body. Moreover, the cellular uptake of calcium in Caco-2 cells showed that YL-Ca could enhance calcium uptake efficiency and protect calcium ions against precipitation caused by dietary inhibitors such as tannic acid, oxalate, phytate and metal ions. The findings indicate that the by-product of Schizochytrium sp. is a promising source for making peptide-calcium bio-products as algae-based functional supplements for human beings.

  3. A Specific Peptide with Calcium-Binding Capacity from Defatted Schizochytrium sp. Protein Hydrolysates and the Molecular Properties.

    Science.gov (United States)

    Cai, Xixi; Yang, Qian; Lin, Jiaping; Fu, Nanyan; Wang, Shaoyun

    2017-03-29

    Marine microorganisms have been proposed as a new kind of protein source. Efforts are needed in order to transform the protein-rich biological wastes left after lipid extraction into value-added bio-products. Thus, the utilization of protein recovered from defatted Schizochytrium sp. by-products presents an opportunity. A specific peptide Tyr-Leu (YL) with calcium-binding capacity was purified from defatted Schizochytrium sp. protein hydrolysates through gel filtration chromatography and RP-HPLC. The calcium-binding activity of YL reached 126.34 ± 3.40 μg/mg. The calcium-binding mechanism was investigated through ultraviolet, fluorescence and infrared spectroscopy. The results showed that calcium ions could form dative bonds with carboxyl oxygen atoms and amino nitrogen atoms as well as the nitrogen and oxygen atoms of amide bonds. YL-Ca exhibited excellent thermal stability and solubility, which was beneficial for its absorption and transport in the basic intestinal tract of the human body. Moreover, the cellular uptake of calcium in Caco-2 cells showed that YL-Ca could enhance calcium uptake efficiency and protect calcium ions against precipitation caused by dietary inhibitors such as tannic acid, oxalate, phytate and metal ions. The findings indicate that the by-product of Schizochytrium sp. is a promising source for making peptide-calcium bio-products as algae-based functional supplements for human beings.

  4. Hydration properties and binding capacities of dietary fibers from bamboo shoot shell and its hypolipidemic effects in mice.

    Science.gov (United States)

    Luo, Xianliang; Wang, Qi; Zheng, Baodong; Lin, Liangmei; Chen, Bingyan; Zheng, Yafeng; Xiao, Jianbo

    2017-02-22

    In the bamboo shoot processing industries, bamboo shoot shells are discarded without any utilization. As a cheap potential dietary fibers resource, bamboo shoot (Leleba oldhami Nakal) shell was decomposed to dietary fibers by multiple enzymes. The extraction yields of insoluble dietary fiber and soluble dietary fiber were 56.21% and 8.67%, respectively. The resulting fibers showed significant swelling capacity, water holding capacity and exhibit in vitro binding capacities to fat, cholesterol, bile acids and nitrites. The administration of bamboo shoot shell fibers improved the lipid metabolism disorderly situation of hyperlipidemia mice. Compared with normal group, total dietary fiber supplement could exhibit the lowest body weight gain (2.84%) in mice, and decrease total cholesterol, triglyceride and low density lipoprotein-cholesterol by 31.53%, 21.35% and 31.53%, respectively; while it can increase high density lipoprotein-cholesterol by 37.6%. The bamboo shoot shell fibers could be a potentially available dietary ingredient in functional food industries.

  5. Comparison of Iron-Binding Ability Between Thr70-NapA and Ser70-NapA of Helicobacter pylori.

    Science.gov (United States)

    Shan, Weiran; Kung, Hsiang-Fu; Ge, Ruiguang

    2016-06-01

    The neutrophil-activating protein (NapA) of Helicobacter pylori (H. pylori), with DNA-binding and iron seizing properties, is a fundamental virulence factor involved in H. pylori-related diseases. Compared with Ser70-NapA strain, Thr70-NapA strain is more intimately correlated with iron-deficiency anemia. To investigate whether two types of proteins differ in iron-binding ability, mutated Thr70-NapA and Ser70-NapA strains were established. Isothermal titration calorimetry (ITC) method was conducted to measure the binding between the NapA protein and Fe(2+) . The structural changes of NapA protein were also tested during iron interaction by fast protein liquid chromatography (FPLC) and circular dichroism (CD) methods. DNA-binding assay was performed for evaluate the affinity of both mutated and wild types of NapA with DNA. Mutated Thr70-NapA had higher iron-binding ability than wild Ser70-NapA. The structural stability of Thr70-NapA was disrupted and became more active along with the rising concentration of Fe(2+) , whereas no similar association was observed between Ser70-NapA and Fe(2+) level. When the iron/protein molar ratio ranged from 10 to 20, both Ser70-NapA and Thr70-NapA displayed weaker DNA-binding ability. Thr70-NapA has much stronger ability to sequester ferrous ion compared with Ser70-NapA in H. pylori. In addition, the DNA-binding property of NapA is dependent upon the Fe(2+) concentration. © 2015 John Wiley & Sons Ltd.

  6. Characteristic of the nutritive value of the protein from rye coryopses. II. Evaluation of rye grain protein quality by Dye-Binding Capacity method

    Directory of Open Access Journals (Sweden)

    K. Kubiczek

    2015-06-01

    Full Text Available The usefulness for breeding porposes of the azosulphonic dye-binding capacity (DBC method by proteins for large scale screening nutritive value characteristic of rye grain protein was studied. It was established that binding capacity of dye by rye grain protein is positively, significantly correlated with protein nutritive value indicators, e.g. CS (Chemical Score. The amounts of the binded dye by 1 g of milled rye grains were positively, significantly correlated with "useful" protein content of grains. DBC plus Kjeldahl protein evaluations are together suitable for mass screening quantitative and qualitative characteristic of rye grain protein.

  7. Fusing a carbohydrate-binding module into the Aspergillus usamii β-mannanase to improve its thermostability and cellulose-binding capacity by in silico design.

    Directory of Open Access Journals (Sweden)

    Cun-Duo Tang

    Full Text Available The AuMan5A, an acidophilic glycoside hydrolase (GH family 5 β-mannanase derived from Aspergillus usamii YL-01-78, consists of an only catalytic domain (CD. To perfect enzymatic properties of the AuMan5A, a family 1 carbohydrate-binding module (CBM of the Trichoderma reesei cellobiohydrolase I (TrCBH I, having the lowest binding free energy with cellobiose, was selected by in silico design, and fused into its C-terminus forming a fusion β-mannanase, designated as AuMan5A-CBM. Then, its encoding gene, Auman5A-cbm, was constructed as it was designed theoretically, and expressed in Pichia pastoris GS115. SDS-PAGE analysis displayed that both recombinant AuMan5A-CBM (reAuMan5A-CBM and AuMan5A (reAuMan5A were secreted into the cultured media with apparent molecular masses of 57.3 and 49.8 kDa, respectively. The temperature optimum of the reAuMan5A-CBM was 75°C, being 5°C higher than that of the reAuMan5A. They were stable at temperatures of 68 and 60°C, respectively. Compared with reAuMan5A, the reAuMan5A-CBM showed an obvious decrease in K m and a slight alteration in V max. In addition, the fusion of a CBM of the TrCBH I into the AuMan5A contributed to its cellulose-binding capacity.

  8. Phosphorus binding by poorly crystalline iron oxides in North Sea sediments

    NARCIS (Netherlands)

    Slomp, C.P.; Gaast, S. J. van der; Raaphorst, W. van

    1996-01-01

    Differential X-ray powder diffraction (DXRD) and extraction procedures were used to characterize the iron oxides present in four sediments from contrasting environments in the North Sea. Stations were located in depositional areas on the southern shelf (German Bight) and on the north-eastern

  9. Phosphorus binding by poorly crystalline iron oxides in North Sea sediments

    NARCIS (Netherlands)

    Slomp, C.P.; Gaast, S. J. van der; Raaphorst, W. van

    1996-01-01

    Differential X-ray powder diffraction (DXRD) and extraction procedures were used to characterize the iron oxides present in four sediments from contrasting environments in the North Sea. Stations were located in depositional areas on the southern shelf (German Bight) and on the north-eastern shelf-s

  10. Effects of Protein-Iron Complex Concentrate Supplementation on Iron Metabolism, Oxidative and Immune Status in Preweaning Calves

    Directory of Open Access Journals (Sweden)

    Robert Kupczyński

    2017-07-01

    Full Text Available The objective of this study was to determine the effects of feeding protein-iron complex (PIC on productive performance and indicators of iron metabolism, hematology parameters, antioxidant and immune status during first 35 days of a calf’s life. Preparation of the complex involved enzymatic hydrolysis of milk casein (serine protease from Yarrowia lipolytica yeast. Iron chloride was then added to the hydrolyzate and lyophilizate. Calves were divided into treated groups: LFe (low iron dose 10 g/day calf of protein-iron complex, HFe (height iron dose 20 g/day calf, and control group. Dietary supplements containing the lower dose of concentrate had a significant positive effect on iron metabolism, while the higher dose of concentrate resulted in increase of total iron binding capacity (TIBC, saturation of transferrin and decrease of and unsaturated iron binding capacity (UIBC, which suggest iron overload. Additionally, treatment with the lower dose of iron remarkably increased the antioxidant parameters, mainly total antioxidant (TAS and glutathione peroxidase activity (GPx. Higher doses of PIC were related to lower total antioxidant status. IgG, IgM, insulin, glucose, TNFα and IGF-1 concentration did not change significantly in either group after supplementation. In practice, the use of protein-iron complex concentrate requires taking into account the iron content in milk replacers and other feedstuffs.

  11. Mechanism of Iron-Dependent Repressor (IdeR Activation and DNA Binding: A Molecular Dynamics and Protein Structure Network Study.

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    Soma Ghosh

    2015-12-01

    Full Text Available Metalloproteins form a major class of enzymes in the living system that are involved in crucial biological functions such as catalysis, redox reactions and as 'switches' in signal transductions. Iron dependent repressor (IdeR is a metal-sensing transcription factor that regulates free iron concentration in Mycobacterium tuberculosis. IdeR is also known to promote bacterial virulence, making it an important target in the field of therapeutics. Mechanistic details of how iron ions modulate IdeR such that it dimerizes and binds to DNA is not understood clearly. In this study, we have performed molecular dynamic simulations and integrated it with protein structure networks to study the influence of iron on IdeR structure and function. A significant structural variation between the metallated and the non-metallated system is observed. Our simulations clearly indicate the importance of iron in stabilizing its monomeric subunit, which in turn promotes dimerization. However, the most striking results are obtained from the simulations of IdeR-DNA complex in the absence of metals, where at the end of 100ns simulations, the protein subunits are seen to rapidly dissociate away from the DNA, thereby forming an excellent resource to investigate the mechanism of DNA binding. We have also investigated the role of iron as an allosteric regulator of IdeR that positively induces IdeR-DNA complex formation. Based on this study, a mechanistic model of IdeR activation and DNA binding has been proposed.

  12. Incessant formation of chain-like mesoporous silica with a superior binding capacity for mercury.

    Science.gov (United States)

    Ravi, S; Selvaraj, M

    2014-04-14

    A novel incessant formation of chain like mesoporous silica (ICMS) has been easily materialized using a mixed surfactant (Pluronic P123 and FC-4) as a structuring reagent in conjunction with a thiol precursor (3-MPS) through a one-pot synthetic method. A particular thiol concentration facilitated the interaction of the micelle head groups to form long-chain micelles, where FC-4 enhanced further growth. The rapid interactions of the micelles and the condensation of silicic acid and its oligomeric derivatives by coordinating 3-MPS through hydrogen bonding interactions leads to form ICMS. The characterization results for the ICMS illustrated that it has an ordered hexagonal pore geometry. The capability of the ICMS for Hg(2+) adsorption was extensively studied under different optimal parameters and the adsorption isothermal values clearly fit with the Langmuir and Freundlich isothermal plots. This novel material exhibited an unprecedentedly high binding affinity toward even microgram levels of mercury ions in wastewater, compared to other thiol-based mesoporous silica.

  13. Zirconium oxide aerogel for effective enrichment of phosphopeptides with high binding capacity.

    Science.gov (United States)

    Zhang, Liyuan; Xu, Jin; Sun, Liangliang; Ma, Junfeng; Yang, Kaiguang; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2011-04-01

    In this study, zirconium oxide (ZrO(2)) aerogel was synthesized via a green sol-gel approach, with zirconium oxychloride, instead of the commonly used alkoxide with high toxicity, as the precursor. With such material, phosphopeptides from the digests of 4 pmol of β-casein with the coexistence of 100 times (mol ratio) BSA could be selectively captured, and identified by MALDI-TOF MS. Due to the large surface area (416.0 m(2) g(-1)) and the mesoporous structure (the average pore size of 10.2 nm) of ZrO(2) aerogel, a 20-fold higher loading capacity for phosphopeptide, YKVPQLEIVPN[pS]AEER (MW 1952.12), was obtained compared to that of commercial ZrO(2) microspheres (341.5 vs. 17.87 mg g(-1)). The metal oxide aerogel was further applied in the enrichment of phosphopeptides from 100 ng nonfat milk, and 17 phosphopeptides were positively identified, with a 1.5-fold improvement in phosphopeptide detection compared with previously reported results. These results demonstrate that ZrO(2) aerogel can be a powerful enrichment material for phosphoproteome study.

  14. Antioxidant capacity of parsley cells (Petroselinum crispum L.) in relation to iron-induced ferritin levels and static magnetic field.

    Science.gov (United States)

    Rajabbeigi, Elham; Ghanati, Faezeh; Abdolmaleki, Parviz; Payez, Atefeh

    2013-12-01

    This study was aimed to evaluate antioxidant response of parsley cells to 21 ppm iron and static magnetic field (SMF; 30 mT). The activity of catalase (CAT) and ascorbate peroxidase (APX) and the contents of malonyldialdehyde, iron and ferritin were measured at 6 and 12 h after treatments. Exposure to SMF increased the activity of CAT in treated cells, while combination of iron and SMF treatments as well as iron supply alone decreased CAT activity, compared to that of control cells. Combination of SMF with iron treatment reduced iron content of the cells and ameliorated mal effect of iron on CAT activity. All treatments reduced APX activity; however, the content of total ascorbate increased in response to iron and SMF+iron. The results showed that among the components of antioxidant system of parsley cells, enhanced activity of CAT in SMF-treated cells and increase of ascorbate in SMF+Fe-treated ones were responsible for the maintenance of membranes integrity. Ferritin contents of SMF- and SMF+Fe-treated cells also decreased significantly 12 h after treatments, compared to those of the control cells. These results cast doubt on the proposed functions of ferritin as a putative reactive oxygen species detoxifying molecule.

  15. Determination of the heavy metal binding capacity of aquatic samples using MetPLATE: a preliminary study.

    Science.gov (United States)

    Huang, F; Bitton, G; Kong, I C

    1999-08-30

    MetPLATE, a microbial toxicity test which is specific for heavy metal toxicity, was used to rapidly determine the heavy metal binding capacity (HMBC) of a wide range of surface waters from Florida and Georgia. HMBC determines the impact of physicochemical factors on metal bioavailability and toxicity. The new developed protocol, using MetPLATE as the toxicity assay, showed that HMBC varied from 1.7 to 39.2 for Cd whereas the ranges for Cu and Ag were Hogtown Creek, Gainesville, FL, and from the St John's river in Jacksonville, FL. Both surface waters displayed the highest HMBC during the Fall season. Preliminary examination of the limited data set confirms that HMBC may be influenced by the concentration of dissolved organic carbon (DOC). These preliminary data show that the impact of physical and chemical parameters on the toxicity of metals in aquatic environments can be rapidly assessed using rapid and low-cost microbiotests.

  16. Iron Mineralogy and Uranium-Binding Environment in the Rhizosphere of a Wetland Soil

    Science.gov (United States)

    Wetlands mitigate the migration of groundwater contaminants through a series of biogeochemical gradients that enhance multiple contaminant-binding processes. The hypothesis of this study was that wetland plant roots contribute organic carbon and release O2 within the ...

  17. AN INVESTIGATION OF THE PROTONATION STATES OF HUMAN LACTOFERRIN IRON-BINDING PROTEIN

    Directory of Open Access Journals (Sweden)

    Lilia Anghel

    2015-06-01

    Full Text Available In this study, the protonation states of ionizable groups of human lactoferrin in various conformations were investigated theoretically, at physiological pH (7.365. These calculations show that the transition of the protein from a conformation to another one is accompanied by changes in the protonation state of specific amino acid residues. Analysis of the pKa calculatons underlined the importance of participation of two arginines and one lysine in the opening / closing of the protein. In addition, it was found that the mechanism of iron release depends on the protonation state of TYR-192. Protonated state of this residue in the closed form of lactoferrin will trigger the opening of protein and release of iron ions.

  18. Tissue Plasminogen Activator Binding to Superparamagnetic Iron Oxide Nanoparticle—Covalent Versus Adsorptive Approach

    Science.gov (United States)

    Friedrich, Ralf P.; Zaloga, Jan; Schreiber, Eveline; Tóth, Ildikó Y.; Tombácz, Etelka; Lyer, Stefan; Alexiou, Christoph

    2016-06-01

    Functionalized superparamagnetic iron oxide nanoparticles are frequently used to develop vehicles for drug delivery, hyperthermia, and photodynamic therapy and as tools used for magnetic separation and purification of proteins or for biomolecular imaging. Depending on the application, there are various possible covalent and non-covalent approaches for the functionalization of particles, each of them shows different advantages and disadvantages for drug release and activity at the desired location.

  19. Iron-Binding Protein Degradation by Cysteine Proteases of Naegleria fowleri

    OpenAIRE

    Moisés Martínez-Castillo; Gerardo Ramírez-Rico; Jesús Serrano-Luna; Mineko Shibayama

    2015-01-01

    Naegleria fowleri causes acute and fulminant primary amoebic meningoencephalitis. This microorganism invades its host by penetrating the olfactory mucosa and then traveling up the mesaxonal spaces and crossing the cribriform plate; finally, the trophozoites invade the olfactory bulbs. During its invasion, the protozoan obtains nutrients such as proteins, lipids, carbohydrates, and cationic ions (e.g., iron, calcium, and sodium) from the host. However, the mechanism by which these ions are obt...

  20. ApproachtoAcuteIronIntoxication: A Case Report

    Directory of Open Access Journals (Sweden)

    Ülkü Özgül

    2011-12-01

    Full Text Available In adults, the main causes of iron poisoning are intake suicide attempts and an overdose of iron during pregnancy. The severity of intoxication depends on the amount of iron. When serum iron level exceeds the iron binding capacity of the body, free radicals occurs, leading to lipid peroxidation and cellular membrane damage. In iron poisoning, especially the liver, heart, kidney, lung, and hematologic systems are affected negatively. Acute iron poisoning can cause serious complications resulting in death. Clinical, laboratory observation and early treatment are important. In this case report, we examined to approach the acute iron poisoning with the occasion of high-dose iron intake for suicide attempt. (Journal of the Turkish Society Intensive Care 2011; 9: 107-9ntakeforsuicideattempt. (Journal of theTurkishSocietyIntensiveCare 2011; 9: 107-9

  1. Modification of arginine residues in ovine prolactin by 1,2-cyclohexanedione. Effect on binding capacity to lactogenic receptors.

    Science.gov (United States)

    Cymes, G D; Atlasovich, F M; Caridad, J J; Iglesias, M M; Wolfenstein-Todel, C

    1994-07-01

    The reactivity of arginine residues in ovine prolactin was studied by reaction with 1,2-cyclohexanedione. Kinetic analysis of the data showed a good fit with two simultaneous pseudo-first-order equations with apparent velocity constants of 0.28 and 1.2 x 10(-2) min-1, corresponding to 1.8 'fast' and 8.7 'slow' residues, respectively. Modification led to a decrease in binding capacity to lactogenic rat liver receptors, and apparently the modification of the two 'fast' reacting arginine residues is responsible for the rapid loss of this capacity. The presence of a non-reacting arginine has been described in human and bovine growth hormones, and it is located near the carboxy-terminus. This lack of reactivity is probably due to the formation of a salt bridge, since the arginine residue becomes susceptible to modification once the peptide is separated from the rest of the molecule. This salt bridge is absent in ovine prolactin, since the homologous arginine residue is reactive with cyclohexanedione. This result suggests that there could be a difference between the three-dimensional structure of ovine prolactin and of the growth hormones, at least near the carboxy-terminal region of the molecule.

  2. Mechanochemical effect in the iron(III) spin crossover complex [Fe(3-MeO-salenEt2]PF6 as studied by heat capacity calorimetry.

    Science.gov (United States)

    Sorai, Michio; Burriel, Ramón; Westrum, Edgar F; Hendrickson, David N

    2008-04-10

    Magnetic and thermal properties of the iron(III) spin crossover complex [Fe(3MeO-salenEt)(2)]PF(6) are very sensitive to mechanochemical perturbations. Heat capacities for unperturbed and differently perturbed samples were precisely determined by adiabatic calorimetry at temperatures in the 10-300 K range. The unperturbed compound shows a cooperative spin crossover transition at 162.31 K, presenting a hysteresis of 2.8 K. The anomalous enthalpy and entropy contents of the transition were evaluated to be Delta(trs)H = 5.94 kJ mol(-1) and Delta(trs)S = 36.7 J K(-1) mol(-1), respectively. By mechanochemical treatments, (1) the phase transition temperature was lowered by 1.14 K, (2) the enthalpy and entropy gains at the phase transition due to the spin crossover phenomenon were diminished to Delta(trs)H = 4.94 kJ mol(-1) and Delta(trs)S = 31.1 J K(-1) mol(-1), and (3) the lattice heat capacities were larger than those of the unperturbed sample over the whole temperature range. In spite of different mechanical perturbations (grinding with a mortar and pestle and grinding in a ball-mill), two sets of heat capacity measurements provided basically the same results. The mechanochemical perturbation exerts its effect more strongly on the low-spin state than on the high-spin state. It shows a substantial increase of the number of iron(III) ions in the high-spin state below the transition temperature. The heat capacities of the diamagnetic cobalt(III) analogue [Co(3MeO-salenEt)(2)]PF(6) also were measured. The lattice heat capacity of the iron compounds has been estimated from either the measurements on the cobalt complex using a corresponding states law or the effective frequency distribution method. These estimations have been used for the evaluation of the transition anomaly.

  3. The presence of high-affinity, low-capacity estradiol-17β binding in rainbow trout scale indicates a possible endocrine route for the regulation of scale resorption

    Science.gov (United States)

    Persson, Petra; Shrimpton, J.M.; McCormick, S.D.; Bjornsson, Bjorn Thrandur

    2000-01-01

    High-affinity, low-capacity estradiol-17β (E2) binding is present in rainbow trout scale. The Kd and Bmax of the scale E2 binding are similar to those of the liver E2 receptor (Kd is 1.6 ± 0.1 and 1.4 ± 0.1 nM, and Bmax is 9.1 ± 1.2 and 23.1 ± 2.2 fmol x mg protein-1, for scale and liver, respectively), but different from those of the high-affinity, low-capacity E2 binding in plasma (Kd is 4.0 ± 0.4 nM and Bmax is 625.4 ± 63.1 fmol x mg protein-1). The E2 binding in scale was displaced by testosterone, but not by diethylstilbestrol. Hence, the ligand binding specificity is different from that of the previously characterized liver E2 receptor, where E2 is displaced by diethylstilbestrol, but not by testosterone. The putative scale E2 receptor thus appears to bind both E2 and testosterone, and it is proposed that the increased scale resorption observed during sexual maturation in both sexes of several salmonid species may be mediated by this receptor. No high-affinity, low-capacity E2 binding could be detected in rainbow trout gill or skin.

  4. Labaratory capacity of differential anemia diagnosis

    Directory of Open Access Journals (Sweden)

    L. M. Meshсheryakova

    2015-06-01

    Full Text Available The paper presents the laboratory values by which modern differential diagnosis of anemias can be performed. This takes into account a widerange of laboratory tests, including: serum ferritin, erythrocyte ferritin, serum iron, total serum iron binding capacity, iron transferrin saturation,transferrin, transferrin receptor, serum vitamin B12, erythrocyte vitamin B12, serum folate, erythrocyte folate, hepsidin, HIF-1 (hypoxiainducible factor-1, immunoglobulins on erythrocytes end others. The combination of these studies helps to accurate diagnosis and appropriate therapy.

  5. Abundances of iron-binding photosynthetic and nitrogen-fixing proteins of Trichodesmium both in culture and in situ from the North Atlantic.

    Directory of Open Access Journals (Sweden)

    Sophie Richier

    Full Text Available Marine cyanobacteria of the genus Trichodesmium occur throughout the oligotrophic tropical and subtropical oceans, where they can dominate the diazotrophic community in regions with high inputs of the trace metal iron (Fe. Iron is necessary for the functionality of enzymes involved in the processes of both photosynthesis and nitrogen fixation. We combined laboratory and field-based quantifications of the absolute concentrations of key enzymes involved in both photosynthesis and nitrogen fixation to determine how Trichodesmium allocates resources to these processes. We determined that protein level responses of Trichodesmium to iron-starvation involve down-regulation of the nitrogen fixation apparatus. In contrast, the photosynthetic apparatus is largely maintained, although re-arrangements do occur, including accumulation of the iron-stress-induced chlorophyll-binding protein IsiA. Data from natural populations of Trichodesmium spp. collected in the North Atlantic demonstrated a protein profile similar to iron-starved Trichodesmium in culture, suggestive of acclimation towards a minimal iron requirement even within an oceanic region receiving a high iron-flux. Estimates of cellular metabolic iron requirements are consistent with the availability of this trace metal playing a major role in restricting the biomass and activity of Trichodesmium throughout much of the subtropical ocean.

  6. Iron porphyrin-modified PVDF membrane as a biomimetic material and its effectiveness on nitric oxide binding

    Science.gov (United States)

    Can, Faruk; Demirci, Osman Cahit; Dumoulin, Fabienne; Erhan, Elif; Arslan, Leyla Colakerol; Ergenekon, Pınar

    2017-10-01

    Nitric oxide (NO) is a reactive gas well-known as an air pollutant causing severe environmental problems. NO is also an important signaling molecule having a strong affinity towards heme proteins in the body. Taking this specialty as a model, a biomimetic membrane was developed by modification of the membrane surface with iron-porphyrin which depicts very similar structure to heme proteins. In this study, PVDF membrane was coated with synthesized (4-carboxyphenyl)-10,15,20-triphenyl-porphyrin iron(III) chloride (FeCTPP) to promote NO fixation on the surface. The coated membrane was characterized in terms of ATR-IR spectra, contact angle measurement, chemical composition, and morphological structure. Contact angle of original PVDF first decreased sharply after plasma treatment and surface polymerization steps but after incorporation of FeCTPP, the surface acquired its hydrophobicity again. NO binding capability of modified membrane surface was evaluated on the basis of X-ray Photoelectron. Upon exposure to NO gas, a chemical shift of Fe+3 and appearance of new N peak was observed due to the electron transfer from NO ligand to Fe ion with the attachment of nitrosyl group to FeCTPP. This modification brings the functionality to the membrane for being used in biological systems such as membrane bioreactor material in biological NO removal technology.

  7. Analysis of NFU-1 Metallocofactor Binding Site Substitutions: Impacts on Iron-Sulfur Cluster Coordination and Protein Structure and Function.

    Science.gov (United States)

    Wesley, Nathaniel A; Wachnowsky, Christine; Fidai, Insiya; Cowan, J A

    2017-09-14

    Iron-sulfur (Fe/S) clusters are ancient prosthetic groups found in numerous metalloproteins and are conserved across all kingdoms of life due to their diverse, yet essential functional roles. Genetic mutations to a specific subset of mitochondrial Fe/S cluster delivery proteins are broadly categorized as disease related under multiple mitochondrial dysfunction syndrome (MMDS), with symptoms indicative of a general failure of the metabolic system. Multiple mitochondrial dysfunction syndrome 1 (MMDS1) arises as a result of the missense mutation in NFU1, an Fe/S cluster scaffold protein, which substitutes a glycine near the Fe/S cluster binding pocket to a cysteine (p.Gly208Cys). This substitution has been shown to promote protein dimerization such that cluster delivery to NFU1 is blocked, preventing downstream cluster trafficking. However, the possibility of this additional cysteine, located adjacent to the cluster binding site, serving as an Fe/S cluster ligand has not yet been explored. To fully understand the consequences of this Gly208Cys replacement, complementary substitutions at the Fe/S cluster binding pocket for native and Gly208Cys NFU1 were made, along with six other variants. Herein we report the results of an investigation on the effect of these substitutions on both cluster coordination and NFU1 structure and function. The data suggest that the G208C substitution does not contribute to cluster binding. Rather, replacement of the glycine at position 208 changes the oligomerization state as a result of global structural alterations that result in the downstream effects manifest as MMDS1, but does not perturb the coordination chemistry of the Fe-S cluster. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  8. Legume seeds and cereal grains’ capacity to accumulate iron while sprouting in order to obtain food fortifi cant.

    Directory of Open Access Journals (Sweden)

    Magdalena Zielińska-Dawidziak

    2016-09-01

    Full Text Available Background. Prepared sprouts, after culturing in a medium with an increased iron concentration, could become a benefi cial food iron fortifi cant. However, the effi cient iron accumulation depends on the plants genus, species and/or varieties. The aim of the study was to indicate the seeds or grains which accumulate iron most effi ciently during the sprouting process. Material and methods. Alfalfa, lentil, lupine and soybean seeds as well as wheat grains were sprouted in abiotic stress conditions induced by the excess of iron(II in culture media. The tolerance of these plants to iron concentration and its accumulation in the material obtained (with FAAS method were analyzed. Results. The smallest tolerance was noted for lentil seeds and wheat grains. Other plants developed in 25 mM solution of FeSO4. The highest accumulation of iron was observed in alfalfa sprouts. However, lupine and soybean seeds are the most recommended raw material for the production of the sprouts on an industrial scale.

  9. α -Actinin TvACTN3 of Trichomonas vaginalis is an RNA-binding protein that could participate in its posttranscriptional iron regulatory mechanism.

    Science.gov (United States)

    Calla-Choque, Jaeson Santos; Figueroa-Angulo, Elisa Elvira; Ávila-González, Leticia; Arroyo, Rossana

    2014-01-01

    Trichomonas vaginalis is a sexually transmitted flagellated protist parasite responsible for trichomoniasis. This parasite is dependent on high levels of iron, favoring its growth and multiplication. Iron also differentially regulates some trichomonad virulence properties by unknown mechanisms. However, there is evidence to support the existence of gene regulatory mechanisms at the transcriptional and posttranscriptional levels that are mediated by iron concentration in T. vaginalis. Thus, the goal of this study was to identify an RNA-binding protein in T. vaginalis that interacts with the tvcp4 RNA stem-loop structure, which may participate in a posttranscriptional iron regulatory mechanism mediated by RNA-protein interactions. We performed RNA electrophoretic mobility shift assay (REMSA) and supershift, UV cross-linking, Northwestern blot, and western blot (WB) assays using cytoplasmic protein extracts from T. vaginalis with the tvcp4 RNA hairpin structure as a probe. We identified a 135-kDa protein isolated by the UV cross-linking assays as α-actinin 3 (TvACTN3) by MALDI-TOF-MS that was confirmed by LS-MS/MS and de novo sequencing. TvACTN3 is a cytoplasmic protein that specifically binds to hairpin RNA structures from trichomonads and humans when the parasites are grown under iron-depleted conditions. Thus, TvACTN3 could participate in the regulation of gene expression by iron in T. vaginalis through a parallel posttranscriptional mechanism similar to that of the IRE/IRP system.

  10. Iron-binding ligands in Dutch estuaries are not affected by UV induced photochemical degradation

    NARCIS (Netherlands)

    Rijkenberg, MJA; Gerringa, LJA; Velzeboer, [No Value; Timmermans, KR; Buma, AGJ; de Baar, HJW; Gerringa, Loes J.A.; Velzeboer, Ilona; Timmermans, Klaas R.; Baar, Hein J.W. de

    2006-01-01

    This study shows that ultraviolet B (UV-B: 280-315 nm) and UV-A (315-400 nm) have no significant influence on the photodegradation of organic Fe(III)-binding ligands in estuarine waters from Marsdiep and Scheldt (The Netherlands). High salinity estuarine seawater from the Marsdiep and Scheldt

  11. The endocytic receptor megalin binds the iron transporting neutrophil-gelatinase-associated lipocalin with high affinity and mediates its cellular uptake

    DEFF Research Database (Denmark)

    Hvidberg, Vibeke; Jacobsen, Christian; Strong, Roland K

    2005-01-01

    in delivering iron to cells during formation of the tubular epithelial cells of the primordial kidney. No cellular receptor for NGAL has been described. We show here that megalin, a member of the low-density lipoprotein receptor family expressed in polarized epithelia, binds NGAL with high affinity, as shown...

  12. Rapid binding of electrostatically stabilized iron oxide nanoparticles to THP-1 monocytic cells via interaction with glycosaminoglycans.

    Science.gov (United States)

    Ludwig, Antje; Poller, Wolfram C; Westphal, Kera; Minkwitz, Susann; Lättig-Tünnemann, Gisela; Metzkow, Susanne; Stangl, Karl; Baumann, Gert; Taupitz, Matthias; Wagner, Susanne; Schnorr, Jörg; Stangl, Verena

    2013-03-01

    Magnetic resonance imaging (MRI) with contrast agents that target specific inflammatory components of atherosclerotic lesions has the potential to emerge as promising diagnostic modality for detecting unstable plaques. Since a high content of macrophages and alterations of the extracellular matrix are hallmarks of plaque instability, these structures represent attractive targets for new imaging modalities. In this study, we compared in vitro uptake and binding of electrostatically stabilized citrate-coated very small superparamagnetic iron oxide particles (VSOP) to THP-1 cells with sterically stabilized carboxydextran-coated Resovist(®). Uptake of VSOP in both THP-1 monocytic cells and THP-derived macrophages (THP-MΦ) was more efficient compared to Resovist(®) without inducing cytotoxicity or modifying normal cellular functions (no changes in levels of reactive oxygen species, caspase-3 activity, proliferation, cytokine production). Importantly, VSOP bound with high affinity to the cell surface and to apoptotic membrane vesicles. Inhibition of glycosaminoglycan (GAG) synthesis by glucose deprivation in THP-MΦ was associated with a significant reduction of VSOP attachment suggesting that the strong interaction of VSOP with the membranes of cells and apoptotic vesicles occurs via binding to negatively charged GAGs. These in vitro experiments show that VSOP-enhanced MRI may represent a new imaging approach for visualizing high-risk plaques on the basis of targeting pathologically increased GAGs or apoptotic membrane vesicles in atherosclerotic lesions. VSOP should be investigated further in appropriate in vivo experiments to characterize accumulation in unstable plaque.

  13. Novel hemin binding domains in the Corynebacterium diphtheriae HtaA protein interact with hemoglobin and are critical for heme iron utilization by HtaA.

    Science.gov (United States)

    Allen, Courtni E; Schmitt, Michael P

    2011-10-01

    The human pathogen Corynebacterium diphtheriae utilizes hemin and hemoglobin as iron sources for growth in iron-depleted environments. The use of hemin iron in C. diphtheriae involves the dtxR- and iron-regulated hmu hemin uptake locus, which encodes an ABC hemin transporter, and the surface-anchored hemin binding proteins HtaA and HtaB. Sequence analysis of HtaA and HtaB identified a conserved region (CR) of approximately 150 amino acids that is duplicated in HtaA and present in a single copy in HtaB. The two conserved regions in HtaA, designated CR1 and CR2, were used to construct glutathione S-transferase (GST) fusion proteins (GST-CR1 and GST-CR2) to assess hemin binding by UV-visual spectroscopy. These studies showed that both domains were able to bind hemin, suggesting that the conserved sequences are responsible for the hemin binding property previously ascribed to HtaA. HtaA and the CR2 domain were also shown to be able to bind hemoglobin (Hb) by the use of an enzyme-linked immunosorbent assay (ELISA) method in which Hb was immobilized on a microtiter plate. The CR1 domain exhibited a weak interaction with Hb in the ELISA system, while HtaB showed no significant binding to Hb. Competitive binding studies demonstrated that soluble hemin and Hb were able to inhibit the binding of HtaA and the CR domains to immobilized Hb. Moreover, HtaA was unable to bind to Hb from which the hemin had been chemically removed. Alignment of the amino acid sequences of CR domains from various Corynebacterium species revealed several conserved residues, including two highly conserved tyrosine (Y) residues and one histidine (H) residue. Site-directed mutagenesis studies showed that Y361 and H412 were critical for the binding to hemin and Hb by the CR2 domain. Biological assays showed that Y361 was essential for the hemin iron utilization function of HtaA. Hemin transfer experiments demonstrated that HtaA was able to acquire hemin from Hb and that hemin bound to HtaA could be

  14. Binding and activation of halocarbons by iron(II) and ruthenium(II)

    Energy Technology Data Exchange (ETDEWEB)

    Kulawiec, R.J.; Faller, J.W.; Crabtree, R.H. (Yale Univ., New Haven, CT (USA))

    1990-03-01

    A series of cyclopentadienylruthenium(II) and -iron(II) complexes contain intact iodoalkanes, p-iodotoluene, or chelating (P, X) (o-halophenyl)diphenylphosphine (X = Cl, Br) ligands. The halocarbons coordinate via {sigma}-donation of a halogen lone pair and retain their carbon-halogen bonds. The complexes are synthesized from the halocarbon, metal halide, and silver(I) ion. Full characterization shows that they are Ru(II) complexes of intact halocarbons rather than Ru(IV) products of oxidative addition. The crystal and molecular structure of one such complex, (Cp(CO)(PPh{sub 3})Ru(IC{sub 6}H{sub 4}-p-CH{sub 3}))PF{sub 6}, is reported (P{bar 1}, a = 10.976 (3) {angstrom}, b = 11.329 (3) {angstrom}, c = 13.666 (4) {angstrom}, {beta} = 102.62 (3){degree}, Z = 2, R{sub 1} = 0.054, R{sub 2} = 0.065).

  15. Brain iron homeostasis.

    Science.gov (United States)

    Moos, Torben

    2002-11-01

    [125I]transferrin in the brain. Some of the 59Fe was detected in CSF in a fraction less than 30 kDa (III). It was estimated that the iron-binding capacity of transferrin in CSF was exceeded, suggesting that iron is transported into the brain in a quantity that exceeds that of transferrin. Accordingly, it was concluded that the paramount iron transport across the BBB is the result of receptor-mediated endocytosis of iron-containing transferrin by capillary endothelial cells, followed by recycling of transferrin to the blood and transport of non-transferrin-bound iron into the brain. It was found that retrograde axonal transport in a cranial motor nerve is age-dependent, varying from almost negligible in the neonatal brain to high in the adult brain. The principle sources of extracellular transferrin in the brain are hepatocytes, oligodendrocytes, and the choroid plexus. As the passage of liver-derived transferrin into the brain is restricted due to the BBB, other candidates for binding iron in the interstitium should be considered. In vitro studies have revealed secretion of transferrin from the choroid plexus and oligodendrocytes. The second part of the thesis encompasses the circulation of iron in the extracellular fluids of the brain, i.e. the brain interstitial fluid and the CSF. As the latter receives drainage from the interstitial fluid, the CSF of the ventricles can be considered a mixture of these fluids, which may allow for analysis of CSF in matters that relate to the brain interstitial fluid. As the choroid plexus is known to synthesize transferrin, a key question is whether transferrin of the CSF might play a role for iron homeostasis by diffusing from the ventricles and subarachnoid space to the brain interstitium. Intracerebroventricular injection of [59Fe125I]transferrin led to a higher accumulation of 59Fe than of [125I]transferrin in the brain. Except for uptake and axonal transport by certain neurons with access to the ventricular CSF, both iron and

  16. Organic Complexation of Dissolved Copper and Iron from Shipboard Incubations in the Central California Current System: Investigating the Impacts of Light Conditions and Phytoplankton Growth on Iron- and Copper-Binding Ligand Characteristics

    Science.gov (United States)

    Mellett, T.; Parker, C.; Brown, M.; Coale, T.; Duckham, C.; Chappell, D.; Maldonado, M. T.; Bruland, K. W.; Buck, K. N.

    2016-02-01

    Two shipboard incubation experiments were carried out in July of 2014 to investigate potential sources and sinks of iron- and copper-binding organic ligands in the surface ocean. Seawater for the experiments was collected from the central California Current System (cCCS) and incubated under varying light conditions and in the presence and absence of natural phytoplankton communities. Incubation treatments were sampled over a period of up to 3 days for measurements of total dissolved copper and iron, and for the concentration and conditional stability constants of copper- and iron-binding organic ligands. Dissolved copper and iron were determined by inductively coupled plasma-mass spectrometry (ICP-MS) following preconcentration on a Nobias PA1 resin. Organic ligand characteristics for iron and copper were determined using a method of competitive ligand exchange-absorptive cathodic stripping voltammetry (CLE-ACSV) with the added competing ligand salicylaldoxime. Trends in ligand concentrations and conditional stability constants across the different treatments and over the course of the incubation experiments will be presented.

  17. The genes that encode the gonococcal transferrin binding proteins, TbpB and TbpA, are differentially regulated by MisR under iron-replete and iron-depleted conditions.

    Science.gov (United States)

    Kandler, Justin L; Acevedo, Rosuany Vélez; Dickinson, Mary Kathryne; Cash, Devin R; Shafer, William M; Cornelissen, Cynthia Nau

    2016-10-01

    Neisseria gonorrhoeae produces two transferrin binding proteins, TbpA and TbpB, which together enable efficient iron transport from human transferrin. We demonstrate that expression of the tbp genes is controlled by MisR, a response regulator in the two-component regulatory system that also includes the sensor kinase MisS. The tbp genes were up-regulated in the misR mutant under iron-replete conditions but were conversely down-regulated in the misR mutant under iron-depleted conditions. The misR mutant was capable of transferrin-iron uptake at only 50% of wild-type levels, consistent with decreased tbp expression. We demonstrate that phosphorylated MisR specifically binds to the tbpBA promoter and that MisR interacts with five regions upstream of the tbpB start codon. These analyses confirm that MisR directly regulates tbpBA expression. The MisR binding sites in the gonococcus are only partially conserved in Neisseria meningitidis, which may explain why tbpBA was not MisR-regulated in previous studies using this related pathogen. This is the first report of a trans-acting protein factor other than Fur that can directly contribute to gonococcal tbpBA regulation.

  18. A diclofenac suppository-nabumetone combination therapy for arthritic pain relief and a monitoring method for the diclofenac binding capacity of HSA site II in rheumatoid arthritis.

    Science.gov (United States)

    Setoguchi, Nao; Takamura, Norito; Fujita, Ken-ichi; Ogata, Kenji; Tokunaga, Jin; Nishio, Toyotaka; Chosa, Etsuo; Arimori, Kazuhiko; Kawai, Keiichi; Yamamoto, Ryuichi

    2013-03-01

    Diclofenac suppository, a non-steroidal anti-inflammatory drug (NSAID), is used widely in rheumatoid arthritis (RA) patients with severe arthritic pain. As the binding percentage of diclofenac to serum proteins is high, its free (unbound) concentration after rectal administration is low. To increase temporarily the free concentration of diclofenac and to enhance its analgesic effect by inhibiting the protein binding of diclofenac, the analgesic effect of diclofenac was examined before and after the start of an inhibitor administration to RA patients with insufficient control of arthritic pain, and the protein binding capacity of diclofenac was evaluated. Binding experiments were performed by ultrafiltration, and arthritic pain was recorded by the face scale. Free fractions of diazepam and diclofenac were augmented by increasing 6-methoxy-2-naphthylacetic acid (6-MNA; the active metabolite of the NSAID nabumetone) concentrations. The free fraction of diazepam increased after the start of nabumetone administration to RA patients, and arthritic pain relief was observed. These results suggest that 6-MNA has an inhibitory effect on the protein binding of diclofenac and the free fraction of diazepam can be used to evaluate the binding capacity of diclofenac. It is considered that diclofenac suppository-nabumetone combination therapy and the method for protein binding monitoring by diazepam can positively benefit RA patients with insufficient control of arthritic pain.

  19. Role of citrate and phosphate anions in the mechanism of iron(III) sequestration by ferric binding protein: kinetic studies of the formation of the holoprotein of wild-type FbpA and its engineered mutants.

    Science.gov (United States)

    Weaver, Katherine D; Gabricević, Mario; Anderson, Damon S; Adhikari, Pratima; Mietzner, Timothy A; Crumbliss, Alvin L

    2010-07-27

    Ferric binding protein A (FbpA) plays a central role in the iron acquisition processes of pathogenic Neisseria gonorrheae, Neisseria meningitidis, and Haemophilus influenzae. FbpA functions as an iron shuttle within the periplasmic space of these Gram-negative human pathogens. Iron is picked up by FbpA at the periplasmic aspect of the outer membrane with concomitant acquisition of a synergistic anion. Here we report the kinetics and mechanisms involved with loading of iron(III) into iron-free FbpA using iron(III) citrate as an iron source in the presence of excess citrate or phosphate (physiologically available anions) at pH 6.5. In the presence of excess phosphate, iron(III) citrate loads into apo-FbpA in three kinetically distinguishable steps, while in the presence of excess citrate, only two steps are discernible. A stable intermediate containing iron(III) citrate-bound FbpA is observed in each case. The observation of an additional kinetic step and moderate increase in apparent rate constants suggests an active role for phosphate in the iron insertion process. To further elucidate a mechanism for iron loading, we report on the sequestration kinetics of iron(III) citrate in the presence of phosphate with binding site mutant apo-FbpAs, H9E, E57D, E57Q, Q58A, Y195F, and Y196H. Tyrosine mutations drastically alter the kinetics and hamper iron sequestration ability. H9E, E57D, and E57Q have near native iron sequestration behavior; however, iron binding rates are altered, enabling assignment of sequential side chain interactions. Additionally, this investigation elaborates on the function of FbpA as a carrier for iron chelates as well as "naked" or free iron as originally proposed.

  20. Acrosin-binding protein (ACRBP) and triosephosphate isomerase (TPI) are good markers to predict boar sperm freezing capacity.

    Science.gov (United States)

    Vilagran, Ingrid; Castillo, Judit; Bonet, Sergi; Sancho, Sílvia; Yeste, Marc; Estanyol, Josep M; Oliva, Rafael

    2013-09-15

    Sperm cryopreservation is the most efficient method for storing boar sperm samples for a long time. However, one of the inconveniences of this method is the large variation between and within boars in the cryopreservation success of their sperm. The aim of the present work was thus to find reliable and useful predictive biomarkers of the good and poor capacity to withstand the freeze-thawing process in boar ejaculates. To find these biomarkers, the amount of proteins present in the total proteome in sperm cells were compared between good freezability ejaculates (GFE) and poor freezability ejaculates (PFE) using the two-dimensional difference gel electrophoresis technique. Samples were classified as GFE and PFE using progressive motility and viability of the sperm at 30 and 240 minutes after thawing, and the proteomes from each group, before starting cryopreservation protocols, were compared. Because two proteins, acrosin binding protein (ACRBP) and triosephosphate isomerase (TPI), presented the highest significant differences between GFE and PFE groups in two-dimensional difference gel electrophoresis assessment, Western blot analyses for ACRBP and TPI were also performed for validation. ACRBP normalized content was significantly lower in PFE than in GFE (P sperm viability and motility was confirmed using Pearson's linear correlation. In conclusion, ACRBP and TPI can be used as markers of boar sperm freezability before starting the cryopreservation procedure, thereby avoiding unnecessary costs involved in this practice.

  1. Decreased binding capacity (Bmax) of muscarinic acetylcholine receptors in fibroblasts from boys with attention-deficit/hyperactivity disorder (ADHD).

    Science.gov (United States)

    Johansson, Jessica; Landgren, Magnus; Fernell, Elisabeth; Lewander, Tommy; Venizelos, Nikolaos

    2013-09-01

    Monoaminergic dysregulation is implicated in attention-deficit/hyperactivity disorder (ADHD), and methylphenidate and amphetamines are the most frequently prescribed pharmacological agents for treating ADHD. However, it has recently been proposed that the core symptoms of the disorder might be due to an imbalance between monoaminergic and cholinergic systems. In this study, we used fibroblast cell homogenates from boys with and without ADHD as an extraneural cell model to examine the cholinergic receptor density, that is, muscarinic acetylcholine receptors (mAChRs). We found that the binding capacity (Bmax) of [³H] Quinuclidinyl benzilate (³H-QNB) to mAChRs was decreased by almost 50 % in the children with ADHD (mean = 30.6 fmol/mg protein, SD = 25.6) in comparison with controls [mean = 63.1 fmol/mg protein, SD = 20.5, p ≤ 0.01 (Student's unpaired t test)]. The decreased Bmax indicates a reduced cholinergic receptor density, which might constitute a biomarker for ADHD. However, these preliminary findings need to be replicated in larger ADHD and comparison cohorts.

  2. Tree species affect cation exchange capacity (CEC) and cation binding properties of organic matter in acid forest soils.

    Science.gov (United States)

    Gruba, Piotr; Mulder, Jan

    2015-04-01

    Soil organic matter (SOM) in forest soil is of major importance for cation binding and acid buffering, but its characteristics may differ among soils under different tree species. We investigated acidity, cation exchange properties and Al bonding to SOM in stands of Scots pine, pedunculate oak, Norway spruce, European beech and common hornbeam in southern Poland. The content of total carbon (Ct) was by far the major contributor to total cation exchange capacity (CECt) even in loamy soils and a strong relationship between Ct and CECt was found. The slope of the regression of CECt to Ct increased in the order hornbeam≈oakacid pH range was smallest for hornbeam and oak, and largest for spruce and pine soils. This was supported by the apparent dissociation constant (pKapp) values of SOM, which were largest in soils under oak. The maximum values of Al saturation were similar between the stands. However, maximum Al bonding to SOM occurred at higher pH values in soils under pine and spruce than under oak. Therefore, at any value in the acid pH range, the SOM in pine soil has less Al complexed and more adsorbed H+ than SOM from oak soils. Such differences in Al and H bonding are not only important for pH buffering and metal solubility controls, but also for stabilization of SOM via saturation of functional groups by Al and H. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Dysmetabolic Hyperferritinemia: All Iron Overload Is Not Hemochromatosis

    Directory of Open Access Journals (Sweden)

    Jasbir Makker

    2015-01-01

    Full Text Available Disturbances in iron metabolism can be genetic or acquired and accordingly manifest as primary or secondary iron overload state. Organ damage may result from iron overload and manifest clinically as cirrhosis, diabetes mellitus, arthritis, endocrine abnormalities and cardiomyopathy. Hemochromatosis inherited as an autosomal recessive disorder is the most common genetic iron overload disorder. Expert societies recommend screening of asymptomatic and symptomatic individuals with hemochromatosis by obtaining transferrin saturation (calculated as serum iron/total iron binding capacity × 100. Further testing for the hemochromatosis gene is recommended if transferrin saturation is >45% with or without hyperferritinemia. However, management of individuals with low or normal transferrin saturation is not clear. In patients with features of iron overload and high serum ferritin levels, low or normal transferrin saturation should alert the physician to other - primary as well as secondary - causes of iron overload besides hemochromatosis. We present here a possible approach to patients with hyperferritinemia but normal transferrin saturation.

  4. Dysmetabolic hyperferritinemia: all iron overload is not hemochromatosis.

    Science.gov (United States)

    Makker, Jasbir; Hanif, Ahmad; Bajantri, Bharat; Chilimuri, Sridhar

    2015-01-01

    Disturbances in iron metabolism can be genetic or acquired and accordingly manifest as primary or secondary iron overload state. Organ damage may result from iron overload and manifest clinically as cirrhosis, diabetes mellitus, arthritis, endocrine abnormalities and cardiomyopathy. Hemochromatosis inherited as an autosomal recessive disorder is the most common genetic iron overload disorder. Expert societies recommend screening of asymptomatic and symptomatic individuals with hemochromatosis by obtaining transferrin saturation (calculated as serum iron/total iron binding capacity × 100). Further testing for the hemochromatosis gene is recommended if transferrin saturation is >45% with or without hyperferritinemia. However, management of individuals with low or normal transferrin saturation is not clear. In patients with features of iron overload and high serum ferritin levels, low or normal transferrin saturation should alert the physician to other - primary as well as secondary - causes of iron overload besides hemochromatosis. We present here a possible approach to patients with hyperferritinemia but normal transferrin saturation.

  5. Fermentation of liquid coproducts and liquid compound diets: Part 2. Effects on pH, acid-binding capacity, organic acids and ethanol during a 6-day period

    NARCIS (Netherlands)

    Scholten, R.H.J.; Rijnen, M.M.J.A.; Schrama, J.W.; Boer, H.; Peet-Schwering, van der C.M.C.; Hartog, den L.A.; Vesseur, P.C.

    2001-01-01

    The effects of a 6-day storage period on changes in pH, acid-binding capacity, level of organic acids and ethanol of three liquid coproducts [liquid wheat starch (LWS), mashed potato steam peel (PSP) and cheese whey (CW)] and two liquid compound diets [liquid grower diet (LGD) and liquid finisher

  6. Tumor necrosis factor-alpha binding capacity and anti-infliximab antibodies measured by fluid-phase radioimmunoassays as predictors of clinical efficacy of infliximab in Crohn's disease

    DEFF Research Database (Denmark)

    Ainsworth, Mark A; Bendtzen, Klaus; Brynskov, Jørn

    2007-01-01

    To investigate if the combined assessment of anti-infliximab antibodies (Ab) and the degree of TNF-alpha binding capacity (TNF-alpha-BC) afforded by infliximab may predict the response to infliximab treatment in patients with Crohn's disease (CD)....

  7. Distribution of dissolved organic carbon and metal-binding capacity among ultrafilterable fractions isolated from selected surface waters of the southeastern United States

    Science.gov (United States)

    Alberts, James J.; Giesy, John P.; Evans, David W.

    1984-06-01

    The binding capacities of surface waters for Cd, Cu, and Pb were determined for eight water samples representing four rivers and two swamps from Florida and Georgia in the southeastern United States The binding capacity ranges were CdBC=0 04 to 0 79 μg atm/L, CuBC=1 0 to 5 4 μg atm/L, and PbBC=5 0 to 17 8 μg atm/L Binding capacity values from the southeastern United States are shown to be in good agreement with values reported from the northeastern part of the country and northern Europe The CdBC was due primarily to inorganic ligand binding, while PbBC was predominantly a result of organic matter The CuBC was due to a complex function of both organic and inorganic binding Significant portions of the CuBC and PbBC could be removed from the waters by ultrafiltration of particles between 0·45 μm and 52 Å in diameter Ultrafiltration, even to removing particles > 13 Å diameter, did not affect the CdBC Distributional studies of the dissolved organic carbon in these systems reveal that significant fractions of the DOC are present in the ultrafilterable fraction which contains significant portions of the CuBC and PbBC

  8. Iron mineralogy and uranium-binding environment in the rhizosphere of a wetland soil

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel I.; Kukkadapu, Ravi; Seaman, John C.; Arey, Bruce W.; Dohnalkova, Alice C.; Buettner, Shea; Li, Dien; Varga, Tamas; Scheckel, Kirk G.; Jaffé, Peter R.

    2016-11-01

    Wetlands mitigate the migration of groundwater contaminants through the creation of biogeochemical gradients that enhance multiple contaminant-binding processes. Our hypothesis was that wetland plants not only contribute organic carbon, produce strong redox gradients, and elevate microbial populations to soils, but together these conditions also promote the formation of Fe (oxyhydr)oxides within the plant rhizosphere that may also contribute to contaminant immobilization. Mineralogy and U binding environments of the rhizosphere (plant-impacted soil zone) were evaluated in samples collected from contaminated and non-contaminated areas of a wetland on the Savannah River Site in South Carolina. Based on Mossbauer spectroscopy, rhizosphere soil collected from the field study site was greatly enriched with poorly crystalline nanoparticulate Fe-oxide/ferrihydrite-like materials and nano-goethite (<15-nm). X-ray computed tomography or various microscopy techniques showed that root plaques, tens-of microns thick, were consisted of highly oriented nanoparticles in an orientation suggestive that the roots were involved in the Fe-nanoparticle formation. Because of detection limits, SEM/EDS could not confirm whether U was enriched in the rhizosphere but did demonstrate that U was enriched on root plaques. Uranium in the plaques was always found in association with P and frequently with Fe. Together these findings suggest that plants may not only alter soil microbial and chemical conditions, but also mineralogical conditions that may be conducive to aqueous contaminant immobilization in wetlands.

  9. Breastfeeding and Red Meat Intake Are Associated with Iron Status in Healthy Korean Weaning-age Infants

    OpenAIRE

    Hong, Jeana; Chang, Ju Young; Shin, Sue; Oh, Sohee

    2017-01-01

    The present study investigated risk factors for iron deficiency (ID) and iron deficiency anemia (IDA) during late infancy, including feeding type and complementary feeding (CF) practice. Healthy term Korean infants (8?15 months) were weighed, and questionnaires regarding delivery, feeding, and weaning were completed by their caregivers. We also examined levels of hemoglobin, serum iron/total iron-binding capacity, serum ferritin, and mean corpuscular volume (MCV). Among 619 infants, ID and ID...

  10. Ambivalent binding between a radical-based pincer ligand and iron.

    Science.gov (United States)

    Harriman, Katie L M; Leitch, Alicea A; Stoian, Sebastian A; Habib, Fatemah; Kneebone, Jared L; Gorelsky, Serge I; Korobkov, Ilia; Desgreniers, Serge; Neidig, Michael L; Hill, Stephen; Murugesu, Muralee; Brusso, Jaclyn L

    2015-06-14

    A complex exhibiting valence delocalization was prepared from 3,5-bis(2-pyridyl)-1,2,4,6-thiatriazinyl (), an inherently redox active pincer-type ligand, coordinated to iron ( ()). Complex can be prepared via two routes, either from the reaction of the neutral radical with FeCl2 or by treatment of the anionic ligand () with FeCl3, demonstrating its unique redox behaviour. Electrochemical studies, solution absorption and solid-state diffuse reflectance measurements along with X-ray crystallography were carried out to elucidate the molecular and solid-state properties. Temperature- and field-dependent Mössbauer spectroscopy coupled with magnetic measurements revealed that exhibits an isolated S = 5/2 ground spin state for which the low-temperature magnetic behaviour is dominated by exchange interactions between neighbouring molecules. This ground state is rationalized on the basis of DFT calculations that predict the presence of strong electronic interactions between the redox active ligand and metal. This interaction leads to the delocalization of β electron density over the two redox active centres and highlights the difficulty in assigning formal charges to .

  11. Wheat and barley allergens associated with baker's asthma. Glycosylated subunits of the alpha-amylase-inhibitor family have enhanced IgE-binding capacity.

    Science.gov (United States)

    Sanchez-Monge, R; Gomez, L; Barber, D; Lopez-Otin, C; Armentia, A; Salcedo, G

    1992-01-15

    A 16 kDa protein, designated CM16*, which strongly binds IgE from baker's-asthma patients has been identified as a glycosylated form of the previously reported WTAI-CM16, which is a subunit of the wheat tetrameric alpha-amylase inhibitor. A glycosylated form (CMb*) of BTAI-CMb, the equivalent inhibitor subunit from barley, has been also found to have significantly enhanced IgE-binding capacity. In all, 14 purified members of the alpha-amylase/trypsin-inhibitor family showed very different IgE-binding capacities when tested by a dot-blot assay. The glycosylated components CM16*, CMb* and the previously described non-glycosylated 14.5 kDa allergen from barley (renamed BMAI-1) were found to be the strongest allergens.

  12. Evaluation of Chemical and Mineralogical Transformation of Iron in Different Soils in Saturated and Field Capacity Conditions

    Directory of Open Access Journals (Sweden)

    M. Saadatpour Mogaddam

    2016-09-01

    Full Text Available Introduction: Redox potential is one of the most important factors affecting on the solubility of iron minerals in soil. Decreasing redox potential in soil reduces Fe3+ to Fe2+, thereby affecting on solubility of Fe minerals. Application of organic matter to soil under waterlogging condition, decrease redox potential and as a consequence, accelerate the transformation of Fe minerals. The objectives of this study were: 1- The effect of waterlogging on the soluble total Fe concentration and transformation of Fe minerals in different soil pH values. 2- The indirect effects of organic matter on solubility of Fe minerals by changing the redox potential of the soils. Materials and Methods: A study was conducted to determine the effects of redox potential on solubility of Fe and transformation of Fe minerals during the time. Four agricultural soils were selected from different regions of Iran. The soil samples were treated with 0 (Cand 2% (O alfalfa powder and then incubated for 12 weeks under 60% Field capacity (F and waterlogged conditions (S. Subsamples were taken after 1and 12 weeks of incubation and the redox potential, pH value, electrical conductivity (EC, soluble cations (such as Ca2+, Mg2+, K+ and Na+ and anions (such as Cl-, SO42-, PO43- and NO3- and soluble Fe concentrations in the subsamples were measured. Concentrations of Fe2+ and Fe3+ species in soil solution were also predicted using Visual MINTEQ speciation program. Mineralogical transformation of Fe minerals was also determined by X-ray diffraction (XRD technique. Results and Discussion: The results in 60% Field capacity condition showed that pH value by organic matter (alfalfa powder application (OF increased significantly (p≤ 0.05 in acid and neutral soils and decreased in calcareous soils when compared to the control (CF. Organic matter is usually capable of lowering pH of alkaline soils by releasing hydrogen ions associated with organic anions or by nitrification in an open

  13. Kilogram-scale synthesis of iron oxy-hydroxides with improved arsenic removal capacity: study of Fe(II) oxidation--precipitation parameters.

    Science.gov (United States)

    Tresintsi, Sofia; Simeonidis, Konstantinos; Vourlias, George; Stavropoulos, George; Mitrakas, Manassis

    2012-10-15

    Various iron oxy-hydroxides were synthesized in a continuous flow kilogram-scale production reactor through the precipitation of FeSO(4) and FeCl(2) in the pH range 3-12 under intense oxidative conditions to serve as arsenic adsorbents. The selection of the optimum adsorbent and the corresponding conditions of the synthesis was based not only on its maximum As(III) and As(V) adsorption capacity but also on its potential efficiency to achieve the arsenic health regulation limit in NSF challenge water. As a result, the adsorbent prepared at pH 4, which consists of schwertmannite, was selected because it exhibited the highest adsorption capacity of 13 μg As(V)/mg, while maintaining a residual arsenic concentration of 10 μg/L at an equilibrium pH 7. The high surface charge and the activation of an ion-exchange mechanism between SO(4)(2-) adsorbed in the Stern layer and arsenate ions were found to significantly contribute to the increased adsorption capacity. Adsorption capacity values observed in rapid scale column experiments illustrate the improved efficiency of the qualified adsorbent compared to the common commercial arsenic adsorbents.

  14. Mössbauer spectroscopic study of iron-chelate trammels

    Science.gov (United States)

    Pal, Sangita; Meena, S. S.; Ningthoujam, R. S.; Goswami, D.

    2014-04-01

    Any kind of waste effluent in the Indian context and other countries contains a lot of iron in any ore. During mining, milling, extraction and purification process iron acts as contaminant towards other metal's purity. It is essential to remove iron to the maximum extent. In this case, an "IN-HOUSE" resin polyacrylamidehydroxamic acid (PHOA) has been designed and developed which is highly hydrophilic three dimensionally cross-linked. It has an excellent iron binding capacity with almost no leaching. Interaction of resin with ammonium ferrous sulphate and red-mod (Fe2O3) is studied using Mössbauer spectroscopy.

  15. Sites for phosphates and iron-sulfur thiolates in the first membranes: 3 to 6 residue anion-binding motifs (nests).

    Science.gov (United States)

    Milner-White, E James; Russell, Michael J

    2005-02-01

    Nests are common three to six amino acid residue motifs in proteins where successive main chain NH groups bind anionic atoms or groups. On average 8% of residues in proteins belong to nests. Nests form a key part of a number of phosphate binding sites, notably the P-loop, which is the commonest of the binding sites for the phosphates of ATP and GTP. They also occur regularly in sites that bind [Fe2S2](RS)4 [Fe3S4](RS)3and [Fe4S4](RS)4 iron-sulfur centers, which are also anionic groups. Both phosphates and iron-sulfur complexes would have occurred in the precipitates within hydrothermal vents of moderate temperature as key components of the earliest metabolism and it is likely existing organisms emerging in this milieu would have benefited from evolving molecules binding such anions. The nest conformation is favored by high proportions of glycine residues and there is evidence for glycine being the commonest amino acid during the stage of evolution when proteins were evolving so it is likely nests would have been common features in peptides occupying the membranes at the dawn of life.

  16. Study of the thermodynamics of chromium(III) and chromium(VI) binding to iron(II/III)oxide or magnetite or ferrite and magnanese(II) iron (III) oxide or jacobsite or manganese ferrite nanoparticles.

    Science.gov (United States)

    Luther, Steven; Brogfeld, Nathan; Kim, Jisoo; Parsons, J G

    2013-06-15

    Removal of chromium(III) or (VI) from aqueous solution was achieved using Fe3O4, and MnFe2O4 nanomaterials. The nanomaterials were synthesized using a precipitation method and characterized using XRD. The size of the nanomaterials was determined to be 22.4±0.9 nm (Fe3O4) and 15.5±0.5 nm (MnFe2O4). The optimal binding pH for chromium(III) and chromium(VI) were pH 6 and pH 3. Isotherm studies were performed, under light and dark conditions, to determine the capacity of the nanomaterials. The capacities for the light studies with MnFe2O4 and Fe3O4 were determined to be 7.189 and 10.63 mg/g, respectively, for chromium(III). The capacities for the light studies with MnFe2O4 and Fe3O4 were 3.21 and 3.46 mg/g, respectively, for chromium(VI). Under dark reaction conditions the binding of chromium(III) to the MnFe2O4 and Fe3O4 nanomaterials were 5.74 and 15.9 mg/g, respectively. The binding capacity for the binding of chromium(VI) to MnFe2O4 and Fe3O4 under dark reaction conditions were 3.87 and 8.54 mg/g, respectively. The thermodynamics for the reactions showed negative ΔG values, and positive ΔH values. The ΔS values were positive for the binding of chromium(III) and for chromium(VI) binding under dark reaction conditions. The ΔS values for chromium(VI) binding under the light reaction conditions were determined to be negative.

  17. Ferrous Iron Binding Key to Mms6 Magnetite Biomineralisation: A Mechanistic Study to Understand Magnetite Formation Using pH Titration and NMR Spectroscopy.

    Science.gov (United States)

    Rawlings, Andrea E; Bramble, Jonathan P; Hounslow, Andrea M; Williamson, Michael P; Monnington, Amy E; Cooke, David J; Staniland, Sarah S

    2016-06-01

    Formation of magnetite nanocrystals by magnetotactic bacteria is controlled by specific proteins which regulate the particles' nucleation and growth. One such protein is Mms6. This small, amphiphilic protein can self-assemble and bind ferric ions to aid in magnetite formation. To understand the role of Mms6 during in vitro iron oxide precipitation we have performed in situ pH titrations. We find Mms6 has little effect during ferric salt precipitation, but exerts greatest influence during the incorporation of ferrous ions and conversion of this salt to mixed-valence iron minerals, suggesting Mms6 has a hitherto unrecorded ferrous iron interacting property which promotes the formation of magnetite in ferrous-rich solutions. We show ferrous binding to the DEEVE motif within the C-terminal region of Mms6 by NMR spectroscopy, and model these binding events using molecular simulations. We conclude that Mms6 functions as a magnetite nucleating protein under conditions where ferrous ions predominate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Effects of carboxylic acids on the uptake of non-transferrin-bound iron by astrocytes.

    Science.gov (United States)

    Keenan, Belinda M; Robinson, Stephen R; Bishop, Glenda M

    2010-01-01

    The concentrations of non-transferrin-bound iron are elevated in the brain during pathological conditions such as stroke and Alzheimer's disease. Astrocytes are specialised for sequestering this iron, however little is known about the mechanisms involved. Carboxylates, such as citrate, have been reported to facilitate iron uptake by intestinal cells. Citrate binds iron and limits its redox activity. The presence of high citrate concentrations in the interstitial fluid of the brain suggests that citrate may be an important ligand for iron transport by astrocytes. This study investigates whether iron accumulation by cultured rat astrocytes is facilitated by citrate or other carboxylates. Contrary to expectations, citrate, tartrate and malate were found to block iron accumulation in a concentration-dependent manner; alpha-ketoglutarate had limited effects, while fumarate, succinate and glutarate had no effect. This blockade was not due to an inhibition of ferric reductase activity. Instead, it appeared to be related to the capacity of these carboxylates to bind iron, since phosphate, which also binds iron, diminished the capacity of citrate, tartrate and malate to block the cellular accumulation of iron. These findings raise the possibility that citrate may have therapeutic potential in the management of neurodegenerative conditions that involve cellular iron overload.

  19. Exposure to positively- and negatively-charged plasma cluster ions impairs IgE-binding capacity of indoor cat and fungal allergens

    OpenAIRE

    NISHIKAWA, Kazuo; Fujimura, Takashi; Ota, Yasuhiro; Abe, Takuya; ElRamlawy, Kareem Gamal; Nakano, Miyako; Takado, Tomoaki; Uenishi, Akira; Kawazoe, Hidechika; Sekoguchi, Yoshinori; Tanaka, Akihiko; Ono, Kazuhisa; Kawamoto, Seiji

    2016-01-01

    Background Environmental control to reduce the amount of allergens in a living place is thought to be important to avoid sensitization to airborne allergens. However, efficacy of environmental control on inactivation of airborne allergens is not fully investigated. We have previously reported that positively- and negatively-charged plasma cluster ions (PC-ions) reduce the IgE-binding capacity of crude allergens from Japanese cedar pollen as important seasonal airborne allergens. Cat (Felis do...

  20. Red Blood Cell Immune Complex Binding Capacity in Children with Sickle Cell Trait (HbAS) Living in P. falciparum Malaria Holoendemic Region of Western Kenya

    Science.gov (United States)

    2012-12-08

    Children with Sickle Cell Trait (HbAS) Living in P. falciparum Malaria Holoendemic Region of Western Kenya Walter Otieno1,2, Benson BA Estambale1...anemia. Children with sickle cell trait (HbAS) are less predisposed to getting severe manifestations of malaria. We carried out a study to determine the...2012 to 00-00-2012 4. TITLE AND SUBTITLE Red Blood Cell Immune Complex Binding Capacity in Children with Sickle Cell Trait (HbAS) Living in P

  1. Reticulocyte hemoglobin content in the diagnosis of iron deficiency in Chinese pre-menopausal women

    Institute of Scientific and Technical Information of China (English)

    LUO Dan; CHEN Yu; WU Wei; ZHANG Feng; XU Jia; CUI Wei; LI Shu-lan; LI Rong-sheng

    2007-01-01

    @@ Pre-menopausal women are at risk for iron deficiency due to menstrual blood losses. The prevalence rates (PR) of iron depletion, iron deficiency anemia (IDA), and iron deficiency were 34.4%, 15.1% and 49.5% in pre-menopausal non-pregnant women respectively in China.1 Traditionally, the diagnosis of iron deficiency relies on the hematological markers (hemoglobin (HGB),mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), red cell distribution width (RDW))and biochemical markers (serum ferritin (SF), serum iron (SI), transferrin saturation (TS), total iron-binding capacity (TIBC)). Recently, the reticulocyte hemoglobin content (CHr) is considered to be used as a marker of iron deficiency.2 The aim of this study was to compare the diagnostic efficiency of CHr with the old markers in diagnosis of iron deficiency in Chinese pre-menopausal women.

  2. Self-peptides with intermediate capacity to bind and stabilize MHC class I molecules may be immunogenic

    DEFF Research Database (Denmark)

    Andersen, M L M; Ruhwald, Morten; Nissen, M H;

    2003-01-01

    Thirty self-peptides were selected on the basis of their predicted binding to H-2b molecules. The binding of peptides was ascertained experimentally by biochemical (KD measurements) and cellular [major histocompatibility complex class I (MHC-I) stabilization] assays. A weak, but significant, corr...

  3. Effects of a Tripeptide Iron on Iron-Deficiency Anemia in Rats.

    Science.gov (United States)

    Xiao, Chen; Lei, Xingen; Wang, Qingyu; Du, Zhongyao; Jiang, Lu; Chen, Silu; Zhang, Mingjie; Zhang, Hao; Ren, Fazheng

    2016-02-01

    This study aims to investigate the effects of a tripeptide iron (REE-Fe) on iron-deficiency anemia rats. Sprague-Dawley rats were randomly divided into seven groups: a normal control group, an iron-deficiency control group, and iron-deficiency groups treated with ferrous sulfate (FeSO4), ferrous glycinate (Fe-Gly), or REE-Fe at low-, medium-, or high-dose groups. The rats in the iron-deficiency groups were fed on an iron-deficient diet to establish iron-deficiency anemia (IDA) model. After the model established, different iron supplements were given to the rats once a day by intragastric administration for 21 days. The results showed that REE-Fe had effective restorative action returning body weight, organ coefficients, and hematological parameters in IDA rats to normal level. In addition, comparing with FeSO4 or Fe-Gly, high-dose REE-Fe was more effective on improving the levels of renal coefficient, total iron-binding capacity, and transferrin. Furthermore, the liver hepcidin messenger RNA (mRNA) expression in the high-dose group was significantly higher (p  0.05) with the normal control group. The findings suggest that REE-Fe is an effective source of iron supplement for IDA rats and might be exploited as a new iron fortifier.

  4. Secretory component as the mucosal transport receptor: separation of physicochemically analogous human IgA fractions with different receptor-binding capacities.

    Science.gov (United States)

    Schiff, J M; Fisher, M M; Underdown, B J

    1986-01-01

    This paper describes the separation and characterization of several IgA fractions from the same human monoclonal source, based on their ability to bind secretory component (SC). The study was undertaken to elucidate features of the immunoglobulin-binding site for SC, and to examine the dependence of mucosal transport on IgA-SC interaction. Enrichment or depletion of SC-binding activity was accomplished on an affinity adsorbant made with SC from human colostral whey. The affinity-purified human IgA fractions contained IgA polymers and were 77% active in rebinding to the adsorbant; this activity was diminished significantly by direct radioiodination. The non-adherent IgA fractions contained both polymer and monomer, and were only 8% active in rebinding to the adsorbant. When the polymer and monomer components were separated from each other, the non-adherent polymer was found to resemble the affinity-purified fraction by all criteria examined including J-chain content, except that the SC-binding capacity was greater than five-fold lower. These findings have two implications for the SC-binding site on human IgA: first, the presence of J-chain is insufficient to bestow IgA with SC-binding activity; second, a critical tyrosine participates in maintaining the SC-binding region, possibly on the IgA heavy chain. The relationship between SC binding and mucosal transport was tested in the rat hepatobiliary model. All radiolabeled human IgA fractions were captured rapidly from blood by the rat liver, but only the SC-binding fractions underwent substantial intact transport to bile (greater than 70% of the injected dose). Even though a nominal proportion of the SC-non-adherent IgA appeared in bile (4-15% of the dose), most IgA in these fractions was rapidly degraded within the liver. Thus, only a small amount of monomeric and polymeric IgA can use alternative receptors to get to bile by diversion from the degradative pathway. Polymeric IgA can undergo efficient transport across

  5. [The binding of iron to normal human erythrocyte membranes and its intracellular penetration as a function of different glucides].

    Science.gov (United States)

    Bouvet, D; Boulard, M; Najean, Y

    1975-04-14

    In vivo intestinal absorption of iron in rat is greatly enhanced by Lactose and D-Xylose. Both sugars are also able to increase the amount of iron bound to the red cell membrane in the animal. Similar effects have been noted when using human normal red cells. Lactose of D-Xylose are able to convert into an active transport curve the linear diffusion curve which is noted when iron is used without any ligand. It is possible to quantify the effect of both sugars on the flux of iron towards the red cell membrane.

  6. Treatment of iron deficiency anemia with Ferro-Folgamma.

    Science.gov (United States)

    Ghinea, Mihaela Maria

    2004-01-01

    Iron deficiency anemia is a hypochromic anemia in which hemoglobin poor synthesis is due to a decrease in the amount of iron in the body. The decrease of iron quantity has many causes: insufficient intake of aliments rich in iron (meat, viscera, green vegetables), increased necessities during growth period, pregnancy, erythrocytes hyperregeneration, high-performance sportsmen, increased loss by digestive way, genito-urinary way, respiratory, hemorrhagic syndromes. Clinically, symptoms and signs specific to all types of anemia and those specific to lack of iron occur besides the symptoms and signs of the underlying disease: atrophic glositis, angular stomatitis, sideropenic dysphagia, pica, skin and nails changes. Laboratory investigations useful for diagnosis are: microcytic, hypochromic anemia, decreased serum iron level, total capacity of iron binding increased, medullar iron store absent, good response to iron therapy. Ferro-Folgamma is one of the most indicated medicines in iron deficiency anemia. Due to its components this medicine has many indications: insufficient alimentary intake concerning iron, folic acid, B12 vitamin, vegetarian alimentation, increased needs during growth period, iron deficiency anaemia secondary to chronic hemorrhages, malnutrition, anemias associated with chronic alcohol intake, preventive treatment of iron deficiency anemia and megaloblastic anemia during pregnancy and lactation.

  7. Binding interactions of dissolved organic matter with iron and copper: Effects of source and pH

    Science.gov (United States)

    Du, Y.; Jaffe, R.

    2014-12-01

    Dissolved organic matter(DOM) fluxes from terrestrial to marine environments have increased as a result of anthropogenic activities and climate change, and DOM is known to facilitate the transport of both metals and trace organics. The nature and composition of DOM may influence its binding properties to metals and thus affect their mobility and fate in aquatic environments. Humic substances make up the majority of DOM in many aquatic ecosystems. Metals such as Fe and Cu are not only important as nutrients in aquatic systems, but also in controlling biogeochemical and ecotoxicological processes respectively. Thus, gaining a better understanding on the interaction of humic substances with Fe or Cu is important in the assessment of the bioavailability of such metals in aquatic systems. In this study, the binding processes of two different DOM samples (Suwanee River humic acid, SRHA and Nordic Lake fulvic acid, NLFA)with Fe(III) and Cu(II) were examined. With the assistance of excitation-emission matrix fluorescence (EEM) and parallel factor analysis (PARAFAC), three humic-like components (C1, C2 and C4), and one microbial humic-like component (C3), were identified in the characterization of the samples. The quenching rates of C2 and C4 fluorescence in the presence of Cu were similar, which were slightly faster than that forC1. In contrast, the C3 fluorescence was significantly less affected by the addition of metals. In the presence of Fe, the most significant quenching was also observed for C2, and the behavior of C4 fluorescence was dependent on the pH value. Some differences in the fluorescence quenching were also observed between the two humic acid standards (one more higher-plant/terrestrially derived vs. the other more microbial/aquatic derived). In addition, pH had a significant effect on the metal binding with significantly lower quenching at lower pH values. Some variations where observed for the higher pH conditions particularly for Cu(II). A modified

  8. DNA Mutagenic Activity and Capacity for HIV-1 Restriction of the Cytidine Deaminase APOBEC3G Depends on Whether DNA or RNA Binds to Tyrosine 315.

    Science.gov (United States)

    Polevoda, Bogdan; Joseph, Rebecca; Friedman, Alan E; Bennett, Ryan P; Greiner, Rebecca; De Zoysa, Thareendra; Stewart, Ryan A; Smith, Harold C

    2017-04-05

    APOBEC3G (A3G) belongs to the AID/APOBEC protein family of cytidine deaminases (CDA) that bind to nucleic acids. A3G mutates the HIV genome by deamination of dC to dU, leading to accumulation of virus-inactivating mutations. Binding to cellular RNAs inhibits A3G binding to substrate single-stranded (ss) DNA and CDA activity. RNA and ssDNA bind to the same three A3G tryptic peptides (amino acids 181-194, 314-320, and 345-374) that form parts of a continuously exposed protein surface extending from the catalytic domain in the C-terminus of A3G to its N-terminus. We show here that the A3G tyrosines 181 and 315 directly cross-link ssDNA. Binding experiments showed that a Y315A mutation alone significantly reduced A3G binding to both ssDNA and RNA, whereas Y181A and Y182A mutations only moderately affected A3G nucleic acid binding. Consistent with these findings, the Y315A mutant exhibited little to no deaminase activity in an E. coli DNA mutator reporter, while Y181A and Y182A mutants retained ~50% of wild-type A3G activity. The Y315A mutant also showed a markedly reduced ability to assemble into viral particles and had reduced antiviral activity. In uninfected cells, the impaired RNA-binding capacity of Y315A was evident by a shift of A3G from high-molecular-mass ribonucleoprotein complexes to low-molecular-mass complexes. We conclude that Y315 is essential for coordinating ssDNA interaction with or entry to the deaminase domain and hypothesize that RNA bound to Y315 may be sufficient to competitively inhibit ssDNA deaminase-dependent antiviral activity.

  9. Total antioxidant capacity, total phenolic content and iron and zinc dialyzability in selected Greek varieties of table olives, tomatoes and legumes from conventional and organic farming.

    Science.gov (United States)

    Drakou, Marina; Birmpa, Angeliki; Koutelidakis, Antonios E; Komaitis, Michael; Panagou, Efstathios Z; Kapsokefalou, Maria

    2015-03-01

    The objective was to compare 10 types of table olives, 11 types of tomatoes and tomato products and 18 types of legumes from conventional or organic farming for selected nutritional properties. All products were tested for their total antioxidant capacity (TAC) (Ferric Reducing Antioxidant Power (FRAP) assay) and total phenolic content (Folin-Ciocalteau method). Tomatoes and legumes were further tested for iron and zinc dialyzability after in vitro digestion. Ascorbic acid content of tomatoes was also measured. The study resulted that the nutritional properties of olives, tomatoes and legumes tested were different among the various cultivars but, in most cases, not between products from organic or conventional farming. Natural black olives, cherry and santorini tomatoes and lentils exhibited superior nutritional properties.

  10. Limiting Factors in Photosynthesis: IV. Iron Stress-Mediated Changes in Light-Harvesting and Electron Transport Capacity and its Effects on Photosynthesis in Vivo.

    Science.gov (United States)

    Terry, N

    1983-04-01

    Using iron stress to reduce the total amount of light-harvesting and electron transport components per unit leaf area, the influence of light-harvesting and electron transport capacity on photosynthesis in sugar beet (Beta vulgaris L. cv F58-554H1) leaves was explored by monitoring net CO(2) exchange rate (P) in relation to changes in the content of Chl.In most light/CO(2) environments, and especially those with high light (>/=1000 microeinsteins photosynthetically active radiation per square meter per second) and high CO(2) (>/=300 microliters CO(2) per liter air), P per area was positively correlated with changes in Chl (a + b) content (used here as an index of the total amount of light-harvesting and electron transport components). This positive correlation of P per area with Chl per area was obtained not only with Fe-deficient plants, but also over the normal range of variation in Chl contents found in healthy, Fe-sufficient plants. For example, light-saturated P per area at an ambient CO(2) concentration close to normal atmospheric levels (300 microliters CO(2) per liter air) increased by 36% with increase in Chl over the normal range, i.e. from 40 to 65 micrograms Chl per square centimeter. Iron deficiency-mediated changes in Chl content did not affect dark respiration rate or the CO(2) compensation point. The results suggest that P per area of sugar beet may be colimited by light-harvesting and electron transport capacity (per leaf area) even when CO(2) is limiting photosynthesis as occurs under field conditions.

  11. Safety and efficacy of iron sucrose in patients sensitive to iron dextran: North American clinical trial.

    Science.gov (United States)

    Van Wyck, D B; Cavallo, G; Spinowitz, B S; Adhikarla, R; Gagnon, S; Charytan, C; Levin, N

    2000-07-01

    Sensitivity to iron dextran is a potent obstacle to maintaining optimum iron status in patients with dialysis-associated anemia. As part of the North American clinical trials for iron sucrose injection, we examined the effect of intravenous (IV) iron sucrose in 23 hemodialysis patients with documented sensitivity to iron dextran, ongoing epoetin alfa therapy, and below-target-range hemoglobin (Hgb) levels (iron dextran were judged to be mild (n = 16; group A) or severe (n = 7; group B). We prospectively examined adverse events and vital signs after administering 100 mg of IV iron sucrose in each of 10 consecutive dialysis treatment sessions and compared results with those recorded in each of three consecutive dialysis sessions without iron treatment. We administered iron sucrose by IV push over 5 minutes to group A patients and by IV push over 5 minutes or IV infusion over 15 to 30 minutes to group B patients. We did not administer a test dose. Results showed no serious adverse drug reactions after a total of 223 doses of iron sucrose (184 doses by IV push, 39 doses by IV infusion). Intradialytic blood pressure changes after IV iron sucrose injection did not differ from those recorded during dialysis sessions without treatment. An increase in values for Hgb, hematocrit, transferrin saturation, and ferritin, coupled with no significant change in epoetin dose and a decrease in total iron-binding capacity, confirmed the efficacy of iron sucrose injection in managing anemia. We conclude that iron sucrose injection is safe and effective in the management of anemia in patients sensitive to iron dextran and can be administered without a test dose by IV push or infusion.

  12. Improving stability of virus-like particles by ion-exchange chromatographic supports with large pore size: advantages of gigaporous media beyond enhanced binding capacity.

    Science.gov (United States)

    Yu, Mengran; Li, Yan; Zhang, Songping; Li, Xiunan; Yang, Yanli; Chen, Yi; Ma, Guanghui; Su, Zhiguo

    2014-02-28

    Limited binding capacity and low recovery of large size multi-subunits virus-like particles (VLPs) in conventional agarose-gel based chromatographic supports with small pores have long been a bottleneck limiting the large scale purification and application of VLPs. In this study, four anion exchange media including DEAE-Sepharose FF (DEAE-FF), DEAE-Capto, gigaporous DEAE-AP-120nm and DEAE-AP-280nm with average pore diameters of 32nm, 20nm, 120nm and 280nm, respectively, were applied for purification of hepatitis B virus surface antigen (HBsAg) VLPs. Pore size effects of media on the VLPs adsorption equilibrium, adsorption kinetics, dynamic binding capacity (DBC), and recovery were investigated in detail. According to the confocal laser scanning microscopy observation, adsorption of the VLPs in DEAE-FF and DEAE-Capto was mostly confined to a thin shell on the outer surface of the beads, leaving the underlying pore space and the binding sites inaccessibly, while the large pores in gigaporous media enabled the VLPs to access to the interior pore spaces by diffusion transport efficiently. Compared to the most widely used DEAE-FF, gigaporous media DEAE-AP-280nm gained about 12.9 times increase in static adsorption capacity, 8.0 times increase in DBC, and 11.4 times increase in effective pore diffusivity. Beyond increasing the binding capacity and enhancing the mass transfer, the gigaporous structure also significantly improved the stability of the VLPs during intensive adsorption-desorption process by lowing the multi-point interaction between the VLPs and binding sites in the pores. At 2.0mg/mL-media loading quantity, about 85.5% VLPs were correctly self-assembled after the chromatography with DEAE-AP-280nm media; oppositely about 85.2% VLPs lost their normal assembly with DEAE-FF due to irreversible disassembly. Comparative investigation was made to study the purifying performance of these four chromatographic media for actual VLPs purification from recombinant

  13. Viability, differentiation capacity, and detectability of super-paramagnetic iron oxide-labeled muscle precursor cells for magnetic-resonance imaging.

    Science.gov (United States)

    Azzabi, Fahd; Rottmar, Markus; Jovaisaite, Virginija; Rudin, Markus; Sulser, Tullio; Boss, Andreas; Eberli, Daniel

    2015-02-01

    Cell therapies are a promising approach for the treatment of a variety of human conditions including stress urinary incontinence, but their success greatly depends on the biodistribution, migration, survival, and differentiation of the transplanted cells. Noninvasive in vivo cell tracking therefore presents an important aspect for translation of such a procedure into the clinics. Upon labeling with superparamagnetic iron oxide (SPIO) nanoparticles, cells can be tracked by magnetic resonance imaging (MRI), but possible adverse effect of the labeling have to be considered when labeling stem cells with SPIOs. In this study, human muscle precursor cells (hMPC) were labeled with increasing concentrations of SPIO nanoparticles (100-1600 μg/mL) and cell viability and differentiation capacity upon labeling was assessed in vitro. While a linear dependence between cell viability and nanoparticle concentration could be observed, differentiation capacity was not affected by the presence of SPIOs. Using a nude mouse model, a concentration (400 μg/mL) could be defined that allows reliable detection of hMPCs by MRI but does not influence myogenic in vivo differentiation to mature and functional muscle tissue. This suggests that such an approach can be safely used in a clinical setting to track muscle regeneration in patients undergoing cell therapy without negative effects on the functionality of the bioengineered muscle.

  14. Viability, Differentiation Capacity, and Detectability of Super-Paramagnetic Iron Oxide-Labeled Muscle Precursor Cells for Magnetic-Resonance Imaging

    Science.gov (United States)

    Azzabi, Fahd; Rottmar, Markus; Jovaisaite, Virginija; Rudin, Markus; Sulser, Tullio; Boss, Andreas

    2015-01-01

    Cell therapies are a promising approach for the treatment of a variety of human conditions including stress urinary incontinence, but their success greatly depends on the biodistribution, migration, survival, and differentiation of the transplanted cells. Noninvasive in vivo cell tracking therefore presents an important aspect for translation of such a procedure into the clinics. Upon labeling with superparamagnetic iron oxide (SPIO) nanoparticles, cells can be tracked by magnetic resonance imaging (MRI), but possible adverse effect of the labeling have to be considered when labeling stem cells with SPIOs. In this study, human muscle precursor cells (hMPC) were labeled with increasing concentrations of SPIO nanoparticles (100–1600 μg/mL) and cell viability and differentiation capacity upon labeling was assessed in vitro. While a linear dependence between cell viability and nanoparticle concentration could be observed, differentiation capacity was not affected by the presence of SPIOs. Using a nude mouse model, a concentration (400 μg/mL) could be defined that allows reliable detection of hMPCs by MRI but does not influence myogenic in vivo differentiation to mature and functional muscle tissue. This suggests that such an approach can be safely used in a clinical setting to track muscle regeneration in patients undergoing cell therapy without negative effects on the functionality of the bioengineered muscle. PMID:24988198

  15. Decreased serum hepcidin concentration correlates with brain iron deposition in patients with HBV-related cirrhosis.

    Directory of Open Access Journals (Sweden)

    Dong Lin

    Full Text Available PURPOSE: Excessive brain iron accumulation contributes to cognitive impairments in hepatitis B virus (HBV-related cirrhotic patients. The underlying mechanism remains unclear. Hepcidin, a liver-produced, 25-aminoacid peptide, is the major regulator of systemic iron metabolism. Abnormal hepcidin level is a key factor in some body iron accumulation or deficiency disorders, especially in those associated with liver diseases. Our study was aimed to explore the relationship between brain iron content in patients with HBV-related cirrhosis and serum hepcidin level. METHODS: Seventy HBV-related cirrhotic patients and forty age- sex-matched healthy controls were enrolled. Brain iron content was quantified by susceptibility weighted phase imaging technique. Serum hepcidin as well as serum iron, serum transferrin, ferritin, soluble transferrin receptor, total iron binding capacity, and transferrin saturation were tested in thirty cirrhotic patients and nineteen healthy controls. Pearson correlation analysis was performed to investigate correlation between brain iron concentrations and serum hepcidin, or other iron parameters. RESULTS: Cirrhotic patients had increased brain iron accumulation compared to controls in the left red nuclear, the bilateral substantia nigra, the bilateral thalamus, the right caudate, and the right putamen. Cirrhotic patients had significantly decreased serum hepcidin concentration, as well as lower serum transferring level, lower total iron binding capacity and higher transferrin saturation, compared to controls. Serum hepcidin level negatively correlated with the iron content in the right caudate, while serum ferritin level positively correlated with the iron content in the bilateral putamen in cirrhotic patients. CONCLUSIONS: Decreased serum hepcidin level correlated with excessive iron accumulation in the basal ganglia in HBV-related cirrhotic patients. Our results indicated that systemic iron overload underlined regional

  16. The effects of lean beef supplementation on the iron status of college athletes

    Directory of Open Access Journals (Sweden)

    Johnson J

    2012-07-01

    Full Text Available Jocelyn Johnson, Danielle Burke, Matthew Vukovich, Kendra KattelmannHealth and Nutritional Sciences Department, South Dakota State University, Brookings, SD, USAAbstract: The purpose of this study was to determine whether weekly supplementation with nine ounces of prepackaged lean beef sticks could maintain the iron status of college endurance athletes. Thirty-four college endurance athletes (20 female, 14 male were stratified by sex, baseline serum ferritin concentration, and use of iron supplements, and randomized into an intervention (n = 18 or control (n = 16 group. The participants in the intervention group supplemented their usual diet with nine ounces of prepackaged lean beef sticks per week and a daily multivitamin/mineral supplement containing 18 mg iron. The participants in the control group consumed their normal diet and the daily multivitamin/mineral supplement only. Body composition, dietary intake, and blood markers of iron status (hemoglobin, hematocrit, serum iron, serum ferritin, and total iron binding capacity were measured at baseline and postintervention. A two-way analysis of variance with group and time as treatment factors was used to determine the main effect of beef supplementation on variables measured. None of the participants in this study was categorized as iron deficient at baseline or postintervention. Heme iron intake was significantly greater (P < 0.003 in the intervention group (3.1 ± 0.3 mg per day than in the control group (1.5 ± 0.3 mg per day as a result of the intervention. The intervention participants had significant improvements in hematocrit concentrations; there were, however, no differences in blood iron parameters of serum iron, hemoglobin, serum ferritin, or total iron binding capacity as a result of the intervention. The results of this study suggest that daily intake of bioavailable iron may attenuate the effects of exercise on the iron status of endurance athletes.Keywords: bioavailable iron

  17. Mother's iron status, breastmilk iron and lactoferrin--are they related?

    Science.gov (United States)

    Shashiraj; Faridi, M M A; Singh, O; Rusia, U

    2006-07-01

    Exclusive breastfeeding is recommended till 6 months age. Factors regulating the breastmilk iron and lactoferrin levels are incompletely known. Considering high prevalence of nutritional anemia in lactating mothers, we studied the iron status of lactating mothers, their breastmilk iron and lactoferrin levels to determine any relationship between them. Prospective study with 6 months follow-up. Tertiary care referral hospital. Hundred nonanemic and 100 anemic mothers with their babies recruited at birth. Fifty-two nonanemic and 50 anemic mothers and their babies completed the 6-month follow-up. Hemoglobin (Hb), total iron binding capacity (TIBC), percent transferrin saturation (%TS), serum iron (SI) and serum ferritin measured on day 1 and 6 months postpartum. Breastmilk iron and lactoferrin measured on day 1, 14 weeks and 6 months after delivery. Breastmilk iron decreased progressively from day 1 to 14 weeks and at 6 months in both groups, but no significant difference was noted between nonanemic and anemic mothers (P>0.05). Significant decline in breastmilk lactoferrin concentration from day 1 to 14 weeks in nonanemic and anemic mothers (P<0.001) noted. Hemoglobin, TIBC, %TS, SI and serum ferritin of both groups had no correlation with breastmilk iron and lactoferrin concentration on day 1, 14 weeks and 6 months after delivery. Breastmilk iron and lactoferrin concentration had no relationship with the mother's Hb and iron status.

  18. Effect of iron supplementation on maximal oxygen uptake in female athletes

    Directory of Open Access Journals (Sweden)

    Rađen Slavica

    2011-01-01

    Full Text Available Background/Aim. Iron is a vital constituent of hemoglobin, myoglobin, and some mitochondrial enzymes; therefore, body iron deficiency may result in reduced aerobic capacity. The aim of this study was to evaluate the effects of daily oral iron supplementation on body iron status, and the maximal oxygen uptake (VO2max in female athletes with latent iron deficiency, as well as with irondeficiency anemia. Methods. A total of 37 female volleyball players were included in the study. Seventeen female athletes had latent iron deficiency, and 20 ones iron deficiency anemia. Both groups were divided into the experimental and the control group. The experimental groups received a daily oral iron supplement (200 mg ferrous sulfate, for a two-month training course. Iron status was determined by serum parameters as follows: red blood cells count, hemoglobin concentration, serum iron and ferritin levels, an unsaturated iron binding capacity, total iron binding capacity and transferrin saturation. VO2max was determined by an indirect test. Results. Statistical difference between the latent iron deficient group versus the iron deficient anemic group was found regarding VO2max (p < 0.001. There were correlations between hemoglobin concentration and VO2max in the latent iron deficient group, as well as in the iron deficient anaemic group (p < 0.05. After two months, there was a significant increase in VO2max in all groups (from 7.0% to 18.2%. Values of VO2max at the end of training period were significantly different (45.98 ± 1.76 vs 42.40 ± 1.22 mL/kg/min; p <0.001 between the experimental and the control group only in female athletes with iron deficiency anemia. After the supplementation, markers of iron status were significantly higher in supplemented groups than in the controls. Conclusion. VO2max was significantly lower in the iron deficient anemic group versus the latent iron deficient group. Iron supplementation during a two-month training period

  19. Radiation-induced and sonochemical degradation of chitosan as a way to increase its fat-binding capacity

    Science.gov (United States)

    Czechowska-Biskup, R.; Rokita, B.; Ulanski, P.; Rosiak, J. M.

    2005-07-01

    Three physical methods of chitosan degradation: irradiation in dry state, irradiation in aqueous solution and sonication in aqueous solution were tested and compared in the terms of yields and side effects. The influence of average molecular weight of chitosan in its fat-binding ability in vitro has been studied by using a biopharmaceutical model of digestive tract. It was found that reduction in molecular weight leads to a significant increase in the amount of fat bound by 1 g of chitosan. Thus, radiation- or sonochemical treatment may be useful in improving fat-binding properties of chitosan as an active component of dietary food additives.

  20. Development of porcine ficolin-alpha monoclonal and polyclonal antibodies for determining the binding capacity of multiple GlcNAc-binding proteins to bacterial danger components.

    Science.gov (United States)

    Nahid, M Abu; Ross, Steven J; Umiker, Benjamin R; Li, Huapeng; Sugii, Sunji; Bari, Latiful

    2016-02-01

    Ficolins are a group of oligomeric defense proteins assembled from collagen-like stalks and fibrinogen-like domains that have common biochemical specificity for N-acetyl-d-glucose amine (GlcNAc) and can function as opsonins. In this report, GlcNAc-binding protein (GBP) purified from porcine nonimmune serum was biochemically characterized as ficolin-α. Ficolin-α was used as an immunogen to generate both rabbit polyclonal and murine monoclonal anti-ficolin-α antibodies, which are not yet commercially available. GBPs have been shown to be present in many animals, including humans; however, their functions are largely unknown. GBPs from chicken, dog, horse, bovine, and human sera were isolated using various chromatography methods. Interestingly, anti-ficolin-α antibody showed cross-reaction with those animal sera GBPs. Furthermore, anti-ficolin-α antibody was reactive with the GlcNAc eluate of Escherichia coli O26-bound and Salmonella-bound porcine serum proteins. Functionally, GBPs and bacteria-reactive pig serum proteins were able to bind with pathogen-associated molecular patterns such as lipopolysaccharides and lipoteichoic acids. Our studies demonstrate that ficolin-α specific antibody was reactive with GBPs from many species as well as bacteria-reactive serum proteins. These proteins may play important roles in innate immunity by sensing danger components that can lead to antibacterial activity.

  1. Exercise-induced TBC1D1 Ser237 phosphorylation and 14-3-3 protein binding capacity in human skeletal muscle

    DEFF Research Database (Denmark)

    Frøsig, Christian; Pehmøller, Christian; Birk, Jesper Bratz

    2010-01-01

    TBC1D1 is a Rab-GTPase activating protein involved in regulation of GLUT4 translocation in skeletal muscle. We here evaluated exercise-induced regulation of TBC1D1 Ser237 phosphorylation and 14-3-3 protein binding capacity in human skeletal muscle. In separate experiments healthy men performed all......-out cycle exercise lasting either 30 sec, 2 min or 20 min. After all exercise protocols, TBC1D1 Ser237 phosphorylation increased (~70 - 230%, Pprotein showed a similar pattern of regulation...... increasing 60 - 250% (Pprotein kinase (AMPK) induced both Ser237 phosphorylation and 14-3-3 binding properties on human TBC1D1 when evaluated in vitro. To further characterize the role of AMPK as an upstream kinase regulating TBC1D1, extensor digitorum longus...

  2. Synthesis, characterisation and adsorption properties of a porous copper(II) 3D coordination polymer exhibiting strong binding enthalpy and adsorption capacity for carbon dioxide.

    Science.gov (United States)

    Eckold, Pierre; Gee, William J; Hill, Matthew R; Batten, Stuart R

    2012-11-21

    The synthesis and characterisation of microporous coordination polymers containing copper(II) or cobalt(II) and 2-(pyridin-4-yl)malonaldehyde (Hpma) is described and the gas adsorption properties evaluated. Single-crystal X-ray structure determinations identified the structures as [M(pma)(2)]·2X (M = Cu, 1; Co, 2; X = MeOH, MeCN), which contain 3D networks with rutile topology and continuous 1D rectangular channels with diameters ranging from 3 to 4 Å. The materials exhibit low BET surface areas of 143 m(2) g(-1), but possess large capacities for carbon dioxide capture of 14.1 wt%. The small pore channels are shown to account for this, delivering a particularly strong binding enthalpy to adsorbed CO(2) of 38 kJ mol(-1), and a very large adsorption capacity relative to the low surface area.

  3. LABILE IRON IN CELLS AND BODY FLUIDS . Physiology, Pathology and Pharmacology

    Directory of Open Access Journals (Sweden)

    Zvi Ioav Cabantchik

    2014-03-01

    Full Text Available In living systems iron appears predominantly associated with proteins, but can also be detected in forms referred as labile iron, which denotes the combined redox properties of iron and its amenability to exchange between ligands, including chelators. The labile cell iron (LCI composition varies with metal concentration and substances with chelating groups but also with pH and the redox potential. Although physiologically in the lower µM range, LCI plays a key role in cell iron economy as cross-roads of metabolic pathways. LCI levels are continually regulated by an iron-responsive machinery that balances iron uptake versus deposition into ferritin. However, LCI rises aberrantly in some cell types due to faulty cell utilization pathways or infiltration by pathological iron forms that are found in hemosiderotic plasma. As LCI attains pathological levels, it can catalyze reactive O species (ROS formation that, at particular threshold, can surpass cellular anti-oxidant capacities and seriously damage its constituents. While in normal plasma and interstitial fluids, virtually all iron is securely carried by circulating transferrin (that renders iron essentially non-labile, in systemic iron overload (IO, the total plasma iron binding capacity is often surpassed by a massive iron influx from hyperabsorptive gut or from erythrocyte overburdened spleen and/or liver. As plasma transferrin approaches iron saturation, labile plasma iron (LPI emerges in forms that can infiltrate cells by unregulated routes and raise LCI to toxic levels. Despite the limited knowledge available on LPI speciation in different types and degrees of iron overload, LPI measurements can be and are in fact used for identifying systemic IO and for initiating/adjusting chelation regimens to attain full-day LPI protection. A recent application of labile iron assay is the detection of labile components in iv iron formulations per se as well as in plasma (LPI following parenteral iron

  4. The Role of the Cytoplasmic Heme-binding Protein (PhuS) of Pseudomonas aeruginosa in Intracellular Heme Trafficking and Iron Homeostasis*S⃞

    OpenAIRE

    2009-01-01

    The cytoplasmic heme-binding protein PhuS, encoded within the Fur-regulated Pseudomonas heme utilization (phu) operon, has previously been shown to traffic heme to the iron-regulated heme oxygenase (HO). We further investigate the role of PhuS in heme trafficking to HO on disruption of the phuS and hemO genes in a Pseudomonas aeruginosa siderophore-deficient and wild-type background. Previous studies have shown that deletion of hemO prevents the cells from utilizin...

  5. Diverted Total Synthesis of Promysalin Analogs Demonstrates That an Iron-Binding Motif Is Responsible for Its Narrow-Spectrum Antibacterial Activity.

    Science.gov (United States)

    Steele, Andrew D; Keohane, Colleen E; Knouse, Kyle W; Rossiter, Sean E; Williams, Sierra J; Wuest, William M

    2016-05-11

    Promysalin is a species-specific Pseudomonad metabolite with unique bioactivity. To better understand the mode of action of this natural product, we synthesized 16 analogs utilizing diverted total synthesis (DTS). Our analog studies revealed that the bioactivity of promysalin is sensitive to changes within its hydrogen bond network whereby alteration has drastic biological consequences. The DTS library not only yielded three analogs that retained potency but also provided insights that resulted in the identification of a previously unknown ability of promysalin to bind iron. These findings coupled with previous observations hint at a complex multifaceted role of the natural product within the rhizosphere.

  6. Ribosomal RNA in Alzheimer disease is oxidized by bound redox-active iron.

    Science.gov (United States)

    Honda, Kazuhiro; Smith, Mark A; Zhu, Xiongwei; Baus, Diane; Merrick, William C; Tartakoff, Alan M; Hattier, Thomas; Harris, Peggy L; Siedlak, Sandra L; Fujioka, Hisashi; Liu, Quan; Moreira, Paula I; Miller, Frank P; Nunomura, Akihiko; Shimohama, Shun; Perry, George

    2005-06-03

    Oxidative modification of cytoplasmic RNA in vulnerable neurons is an important, well documented feature of the pathophysiology of Alzheimer disease. Here we report that RNA-bound iron plays a pivotal role for RNA oxidation in vulnerable neurons in Alzheimer disease brain. The cytoplasm of hippocampal neurons showed significantly higher redox activity and iron(II) staining than age-matched controls. Notably, both were susceptible to RNase, suggesting a physical association of iron(II) with RNA. Ultrastructural analysis further suggested an endoplasmic reticulum association. Both rRNA and mRNA showed twice the iron binding as tRNA. rRNA, extremely abundant in neurons, was considered to provide the greatest number of iron binding sites among cytoplasmic RNA species. Interestingly, the difference of iron binding capacity disappeared after denaturation of RNA, suggesting that the higher order structure may contribute to the greater iron binding of rRNA. Reflecting the difference of iron binding capacity, oxidation of rRNA by the Fenton reaction formed 13 times more 8-hydroxyguanosine than tRNA. Consistent with in situ findings, ribosomes purified from Alzheimer hippocampus contained significantly higher levels of RNase-sensitive iron(II) and redox activity than control. Furthermore, only Alzheimer rRNA contains 8-hydroxyguanosine in reverse transcriptase-PCR. Addressing the biological significance of ribosome oxidation by redox-active iron, in vitro translation with oxidized ribosomes from rabbit reticulocyte showed a significant reduction of protein synthesis. In conclusion these results suggest that rRNA provides a binding site for redox-active iron and serves as a redox center within the cytoplasm of vulnerable neurons in Alzheimer disease in advance of the appearance of morphological change indicating neurodegeneration.

  7. Enhanced binding affinity, remarkable selectivity, and high capacity of CO 2 by dual functionalization of a rht-type metal-organic framework

    KAUST Repository

    Li, Baiyan

    2011-12-23

    Open and friendly: The smallest member of the rht-type metal-organic frameworks (MOFs, see picture) constructed by a hexacarboxylate ligand with a nitrogen-rich imino triazine backbone shows a significantly enhanced gas binding affinity relative to all other isoreticular rht-type MOFs. The high adsorption capacity and remarkable selectivity of CO 2 are attributed to the high density of open metal and Lewis basic sites in the framework. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. SALIVA IRON AND FERRITIN LEVELS IN PATIENTS WITH THALASSEMIA AND IRON DEFICIENCY ANEMIA

    Directory of Open Access Journals (Sweden)

    Duran Canatan

    2012-01-01

    Full Text Available

    Most of the  techniques for measuring iron accumulation such as serum iron concentration, iron binding capacity, serum ferritin level, liver biopsy are invasive and hard methods for patients. The changes in trace element concentrations in saliva at different systemic diseases shows the quantity of the element at the body. The aim of this study was to compare the levels of iron and ferritin in saliva and serum in patients  with thalassemia and iron deficiency anemia. For this purpose, 35 healthy children as control group and 71 thalassemia major, 10 thalassemia intermedia and 15 thalassemia trait patients were involved. Their saliva  and serum iron and ferritin levels were measured.  There was no statistically difference between age and gender in all groups and control group (p>0.05.  In all groups saliva iron levels are higher than serum iron levels(p<0.05. Furthermore there was a positive correlation betwen serum and saliva  iron levels in thalassemia major, intermedia and trait groups ( p=0.000, r=0.972, r=0.720, r=0.955 and also there was a positive correlation between serum and saliva iron levels in control and iron deficiency group (p= 0.000, r= 0.885, r= 0.368.  In conclusion,  Saliva iron and ferritin levels increase  as well as serum in patients with thalassemia and decrease in patients with iron deficiency anemia. Saliva can be used for diagnosis routinely  to shows the iron overload  and deficiency of the body and its easy applicability and also a non-invasive procedure is important advantage.

  9. SALIVA IRON AND FERRITIN LEVELS IN PATIENTS WITH THALASSEMIA AND IRON DEFICIENCY ANEMIA

    Directory of Open Access Journals (Sweden)

    Duran Canatan

    2012-08-01

    Full Text Available Most of the  techniques for measuring iron accumulation such as serum iron concentration, iron binding capacity, serum ferritin level, liver biopsy are invasive and hard methods for patients. The changes in trace element concentrations in saliva at different systemic diseases shows the quantity of the element at the body. The aim of this study was to compare the levels of iron and ferritin in saliva and serum in patients  with thalassemia and iron deficiency anemia. For this purpose, 35 healthy children as control group and 71 thalassemia major, 10 thalassemia intermedia and 15 thalassemia trait patients were involved. Their saliva  and serum iron and ferritin levels were measured.  There was no statistically difference between age and gender in all groups and control group (p>0.05.  In all groups saliva iron levels are higher than serum iron levels(p<0.05. Furthermore there was a positive correlation betwen serum and saliva  iron levels in thalassemia major, intermedia and trait groups ( p=0.000, r=0.972, r=0.720, r=0.955 and also there was a positive correlation between serum and saliva iron levels in control and iron deficiency group (p= 0.000, r= 0.885, r= 0.368.  In conclusion,  Saliva iron and ferritin levels increase  as well as serum in patients with thalassemia and decrease in patients with iron deficiency anemia. Saliva can be used for diagnosis routinely  to shows the iron overload  and deficiency of the body and its easy applicability and also a non-invasive procedure is important advantage.

  10. The Werner syndrome protein is distinguished from the Bloom syndrome protein by its capacity to tightly bind diverse DNA structures.

    Science.gov (United States)

    Kamath-Loeb, Ashwini; Loeb, Lawrence A; Fry, Michael

    2012-01-01

    Loss of Werner syndrome helicase-exonuclease (WRN) or of its homolog Bloom syndrome helicase (BLM) results in different inherited disorders. Whereas Werner syndrome is characterized by premature onset of aging and age-associated diseases, Bloom syndrome involves developmental abnormalities and increased predisposition to diverse malignancies. To identify biochemical differences between WRN and BLM that might contribute to the dissimilar outcomes of their loss, we compared their abilities to unwind and bind in vitro diverse DNA structures. Full-length recombinant WRN and BLM proteins expressed in and purified from Sf9 insect cells unwound to comparable extents and with similar K(m) values partial DNA duplex, splayed arm DNA and G'2 bimolecular quadruplex DNA. However, WRN resolved bubble DNA ∼25-fold more efficiently than BLM. The two enzymes were mainly distinguished by their contrasting abilities to bind DNA. WRN bound partial duplexes, bubble and splayed arm DNA and G'2 bimolecular and G4 four-molecular quadruplexes with dissociation constants of 0.25 to 25 nM. By contrast, BLM formed substantial complexes with only G4 quadruplex DNA while binding only marginally other DNA structures. We raise the possibility that in addition to its enzymatic activities WRN may act as a scaffold for the assembly on DNA of additional DNA processing proteins.

  11. The Werner syndrome protein is distinguished from the Bloom syndrome protein by its capacity to tightly bind diverse DNA structures.

    Directory of Open Access Journals (Sweden)

    Ashwini Kamath-Loeb

    Full Text Available Loss of Werner syndrome helicase-exonuclease (WRN or of its homolog Bloom syndrome helicase (BLM results in different inherited disorders. Whereas Werner syndrome is characterized by premature onset of aging and age-associated diseases, Bloom syndrome involves developmental abnormalities and increased predisposition to diverse malignancies. To identify biochemical differences between WRN and BLM that might contribute to the dissimilar outcomes of their loss, we compared their abilities to unwind and bind in vitro diverse DNA structures. Full-length recombinant WRN and BLM proteins expressed in and purified from Sf9 insect cells unwound to comparable extents and with similar K(m values partial DNA duplex, splayed arm DNA and G'2 bimolecular quadruplex DNA. However, WRN resolved bubble DNA ∼25-fold more efficiently than BLM. The two enzymes were mainly distinguished by their contrasting abilities to bind DNA. WRN bound partial duplexes, bubble and splayed arm DNA and G'2 bimolecular and G4 four-molecular quadruplexes with dissociation constants of 0.25 to 25 nM. By contrast, BLM formed substantial complexes with only G4 quadruplex DNA while binding only marginally other DNA structures. We raise the possibility that in addition to its enzymatic activities WRN may act as a scaffold for the assembly on DNA of additional DNA processing proteins.

  12. Binding affinity and capacities for ytterbium(3+) and hafinum(4+) by chemical entities of plant tissue fragments.

    Science.gov (United States)

    Worley, R; Clearfield, A; Ellis, W C

    2002-12-01

    The binding affinity of ytterbium (Yb3+) and hafinum (Hf4+) to ligands of chemical entities of fragments of bermudagrass tissues and their resistance to exchanging Yb with other ligands and to displacement by protons were investigated. Chemical entities of acid resistant NDF (ARNDF), 0.1 N acid detergent fiber (0.1 N ADF), and permanganate cellulose (CELL) were prepared from fragments of bermudagrass hay (Cynodon dactylon [L.] Pers.) obtained by grinding to pass a 2-mm sieve. 175Ytterbium and Yb, as YbCl3, were initially bound to each preparation by soaking for 12 h in pH 5.5 borate buffer to obtain Yb bound onto ligands having affinity constants for Yb equal to or greater than that for the weakly stable borate ligand, Yb > or = borate. The fraction of Yb > or = borate was measured and fragments then sequentially exposed to acetate, citrate, nitrotriacetate (NTA), and EDTA ions to allow exchange of Yb from Yb > or = borate with ligands having affinity constants for Yb equal to or greater than acetate (Yb > or = acetate), citrate (Yb > or = citrate), NTA (Yb > or = NTA), and EDTA (Yb > or = EDTA) ions. Binding of Yb > or = borate indicated the existence of two species of ligands: strong ligands binding essentially 100% of added Yb at levels of 1 to 1,300 ppm (0.1 N ADF) and at 1 to 7,000 ppm (ARNDF); and weaker ligands binding 4 and 8% of the Yb, respectively, at levels of added Yb greater than 1,300 ppm and 7,000 ppm. Ytterbium > or = acetate of ARNDF, but not 0.1 N ADF, was as resistant to exchange as Yb > or = citrate. Ytterbium > or = borate was exchanged extensively (85% or greater) with soluble ligands having affinity constants > or = NTA. Ytterbium resistance to proton displacement at pH of 1.5 increased with Yb > or = EDTA > Yb > or = NTA > Yb > or = citrate > Yb > or = acetate. Very efficient binding of Yb to CELL suggested that such chemical preparations are not representative of native cellulose. Hafnium (4+) was strongly bound to plant tissues rendering

  13. HIV-1 Rev–binding protein accelerates cellular uptake of iron to drive Notch-induced T cell leukemogenesis in mice

    Science.gov (United States)

    Khwaja, Shariq S.; Liu, Hudan; Tong, Caili; Jin, Fang; Pear, Warren S.; van Deursen, Jan; Bram, Richard J.

    2010-01-01

    Somatic activating mutations in Notch1 contribute to the pathogenesis of T cell acute lymphoblastic lymphoma (T-ALL), but how activated Notch1 signaling exerts this oncogenic effect is not completely understood. Here we identify HIV-1 Rev–binding protein (Hrb), a component of the clathrin-mediated endocytosis machinery, as a critical mediator of Notch-induced T-ALL development in mice. Hrb was found to be a direct transcriptional target of Notch1, and Hrb loss reduced the incidence or delayed the onset of T-ALL in mouse models in which activated Notch1 signaling either contributes to or drives leukemogenesis. Consistent with this observation, Hrb supported survival and proliferation of hematopoietic and T cell precursor cells in vitro. We demonstrated that Hrb accelerated the uptake of transferrin, which was required for upregulation of the T cell protooncogene p21. Indeed, iron-deficient mice developed Notch1-induced T-ALL substantially more slowly than control mice, further supporting a critical role for iron uptake during leukemogenesis. Taken together, these results reveal that Hrb is a critical Notch target gene that mediates lymphoblast transformation and disease progression via its ability to satisfy the enhanced demands of transformed lymphoblasts for iron. Further, our data suggest that Hrb may be targeted to improve current treatment or design novel therapies for human T-ALL patients. PMID:20516639

  14. Origin of low sodium capacity in graphite and generally weak substrate binding of Na and Mg among alkali and alkaline earth metals.

    Science.gov (United States)

    Liu, Yuanyue; Merinov, Boris V; Goddard, William A

    2016-04-05

    It is well known that graphite has a low capacity for Na but a high capacity for other alkali metals. The growing interest in alternative cation batteries beyond Li makes it particularly important to elucidate the origin of this behavior, which is not well understood. In examining this question, we find a quite general phenomenon: among the alkali and alkaline earth metals, Na and Mg generally have the weakest chemical binding to a given substrate, compared with the other elements in the same column of the periodic table. We demonstrate this with quantum mechanics calculations for a wide range of substrate materials (not limited to C) covering a variety of structures and chemical compositions. The phenomenon arises from the competition between trends in the ionization energy and the ion-substrate coupling, down the columns of the periodic table. Consequently, the cathodic voltage for Na and Mg is expected to be lower than those for other metals in the same column. This generality provides a basis for analyzing the binding of alkali and alkaline earth metal atoms over a broad range of systems.

  15. Modification of arginine residues in human growth hormone by 1,2-cyclohexanedione: effects on the binding capacity to lactogenic and somatogenic receptors.

    Science.gov (United States)

    Atlasovich, F M; Caridad, J J; Nowicki, C; Santomé, J A; Wolfenstein-Todel, C

    1990-08-15

    Reactivity of arginine residues in human growth hormone was studied by reaction with 1,2-cyclohexanedione. Kinetic analysis of the data showed a good fit to a pseudo first order curve, with an apparent velocity constant k = 1.26 x 10(-2) min-1 and a maximum modification of 9.6 out of the 11 arginines of the molecule. Modification led to a decrease in binding capacity to both lactogenic and somatogenic rat liver receptors. In either case Tsou plots suggest that the modification of two arginine residues is responsible for this behavior, although it cannot be ascertained whether the two relevant residues are the same for both receptor types. Circular dichroism studies indicated no apparent changes in protein conformation in the modified hormone. Binding capacity was restored upon regeneration of arginines by incubation with Tris-HCl buffer. Only the carboxy-terminal peptide was isolated by HPLC from a tryptic digest of succinylated Arg-modified hGH, indicating that 183 is the nonreacting arginine residue.

  16. Origin of low sodium capacity in graphite and generally weak substrate binding of Na and Mg among alkali and alkaline earth metals

    Science.gov (United States)

    Liu, Yuanyue; Merinov, Boris V.; Goddard, William A., III

    2016-04-01

    It is well known that graphite has a low capacity for Na but a high capacity for other alkali metals. The growing interest in alternative cation batteries beyond Li makes it particularly important to elucidate the origin of this behavior, which is not well understood. In examining this question, we find a quite general phenomenon: among the alkali and alkaline earth metals, Na and Mg generally have the weakest chemical binding to a given substrate, compared with the other elements in the same column of the periodic table. We demonstrate this with quantum mechanics calculations for a wide range of substrate materials (not limited to C) covering a variety of structures and chemical compositions. The phenomenon arises from the competition between trends in the ionization energy and the ion-substrate coupling, down the columns of the periodic table. Consequently, the cathodic voltage for Na and Mg is expected to be lower than those for other metals in the same column. This generality provides a basis for analyzing the binding of alkali and alkaline earth metal atoms over a broad range of systems.

  17. 纳米晶体铁的低温热容和热稳定性%LOW TEMPERATURE HEAT CAPACITY AND THERMAL STABILITY OF NANOCRYSTALLINE IRON

    Institute of Scientific and Technical Information of China (English)

    王岚; 谭志诚; 孟霜鹤; 梁东白; 高东升; 孙志忠; 刘振田

    2002-01-01

    用等离子体法制备的纳米晶体铁由XRD和SEM等方法测定其晶粒尺寸的平均值为87nm.用绝热量热方法在79~371K温区精确测定了其低温热容,测量结果比大晶粒Fe的热容值有明显的增强.在80~300 K温区之间增强热容为8%~14%.差示扫描量热(DSC)在高温区的研究结果则表明,纳米晶体Fe在400~700 K温区有一个宽的放热峰,对应于非平衡晶格缺陷所引起的焓释放850 K观察到一个放热峰.是纳米晶体铁从α相向α+γ相转变所引起的%The sample of nanocrystalline iron with the average grain size of 87nm was prepared by thermal plasma technique, and characterized by XRD and SEM. Measurement of low temperature heat capacity of the nano-Fe has been performed in the temperature range of 79~371K with an automated adiabatic calorimeter. Enhanced heat capacities varying from 8% to 14% were observed.The differential scanning calorimetric measurement showed one broad exothermic regime from 400K to700K corresponding to the enthalpy releasing, due to the contribution of nonequibrium lattice defects.An endothermic peak at 850K due to a γ→α + γ phase transition of nc-Fe was observed.

  18. Conflicting effects of BMI and waist circumference on iron status.

    Science.gov (United States)

    Choma, Solomon Simon Ramphai; Alberts, Marianne; Modjadji, Sewela Elizabeth Perpetua

    2015-10-01

    The association between obesity and iron status has a long history and is still receiving attention. However comparative analysis of the association between general obesity (BMI) and visceral obesity (waist circumference) with iron status has not been extensively researched. The aim of the present study is thus to determine if body mass index and waist circumference have the same correlation with iron status. One thousand one hundred and thirty people (225 men and 905 women) aged 30 years and above participated in this study. Anthropometric parameters, haemoglobin, iron and total iron binding capacity concentrations were measured using standard methods. Percentage transferrin saturation was calculated and ferritin concentrations were measured using an enzyme linked immunosorbent assay. Obese or overweight women had significantly lower iron and transferrin saturation concentration when compared to non-obese women. In contrast, women with high waist circumference had comparable plasma iron and transferrin saturation to women with normal waist circumference. Partial correlation analysis and linear regression analysis showed that BMI is negatively and significantly associated with plasma iron, transferrin saturation, Hb and ferritin concentration, whilst waist circumference is positively but insignificantly associated with plasma iron, transferrin saturation, Hb and ferritin concentration. Binary regression analysis showed that obese or overweight people are more likely to have iron deficiency, whilst those with raised waist circumference are more likely to have iron overload. Multivariate analysis showed that body mass index is negatively and significantly associated with low iron status, while waist circumference is positively and insignificantly associated with iron status. This is supported by a comparison of plasma iron, transferrin saturation and ferritin concentrations in participants with high body mass index and normal waist circumference and participants with

  19. Associations between single nucleotide polymorphisms in iron-related genes and iron status in multiethnic populations.

    Directory of Open Access Journals (Sweden)

    Christine E McLaren

    Full Text Available The existence of multiple inherited disorders of iron metabolism suggests genetic contributions to iron deficiency. We previously performed a genome-wide association study of iron-related single nucleotide polymorphisms (SNPs using DNA from white men aged ≥ 25 y and women ≥ 50 y in the Hemochromatosis and Iron Overload Screening (HEIRS Study with serum ferritin (SF ≤ 12 µg/L (cases and controls (SF >100 µg/L in men, SF >50 µg/L in women. We report a follow-up study of white, African-American, Hispanic, and Asian HEIRS participants, analyzed for association between SNPs and eight iron-related outcomes. Three chromosomal regions showed association across multiple populations, including SNPs in the TF and TMPRSS6 genes, and on chromosome 18q21. A novel SNP rs1421312 in TMPRSS6 was associated with serum iron in whites (p = 3.7 × 10(-6 and replicated in African Americans (p = 0.0012.Twenty SNPs in the TF gene region were associated with total iron-binding capacity in whites (p<4.4 × 10(-5; six SNPs replicated in other ethnicities (p<0.01. SNP rs10904850 in the CUBN gene on 10p13 was associated with serum iron in African Americans (P = 1.0 × 10(-5. These results confirm known associations with iron measures and give unique evidence of their role in different ethnicities, suggesting origins in a common founder.

  20. TNF and LT binding capacities in the plasma of arthritis patients: effect of etanercept treatment in juvenile idiopathic arthritis

    DEFF Research Database (Denmark)

    Gudbrandsdottir, S; Larsen, R; Sørensen, L K;

    2004-01-01

    Etanercept (Enbrel) induces a rapid and sustained decline in disease activity in the majority of patients with refractory juvenile idiopathic arthritis (JIA). For unknown reasons, however, a number of JIA patients fail to respond to this therapy. During this treatment neutralisation of tumour...... necrosis factor (TNF, previously termed TNF alpha) and lymphotoxin (LT, previously termed TNF beta) may be mediated by etanercept itself as well as by naturally occurring soluble TNF receptors. In light of this, it was of interest to study the total TNF neutralizing capacity in plasma before and during...... treatment with etanercept....

  1. Iron profile in children with behavioural disorders: a prospective study in a tertiary care hospital in north India.

    Science.gov (United States)

    Mahajan, Garima; Sikka, Meera; Rusia, Usha; Bhatia, M S

    2011-06-01

    Iron deficiency anemia is the most frequent micronutrient deficiency in the developing countries like India especially affecting pregnant women and young children. Iron is an essential element involved in myelin formation, neurotransmitter synthesis and neuro-metabolism. Several behavioural disturbances have been reported in iron deficient children. In the present study, we determined the prevalence of iron deficiency anemia in children with behavioural disorders and assessed the improvement in terms of symptoms (by child behaviour check list), haematological parameters and iron status after treatment with oral iron. In this prospective study, 44 children in the age group of 3-12 years who were diagnosed with behavioural disorders were evaluated. Complete blood counts using automated hematology analyzer and iron parameters (serum iron, total iron binding capacity, % transferrin saturation and serum ferritin) were measured in all the patients to assess the prevalence of iron deficiency in these children. Thirty age matched controls were also studied. Iron deficiency was found in 32 (73%) children, as assessed by transferrin saturation <16% and/or serum ferritin <16 μg/l. Following treatment with iron for 100 ± 10 days, there was a statistically (P ≤ 0.05) significant improvement in the clinical features, haematological profile and iron status. The presence of iron deficiency in children with behavioural disorders and subsequent improvement in clinical features, haematological profile and iron status suggests a possible causal relationship between iron deficiency and behavioural disorders.

  2. Analysis of the draft genome of Pseudomonas fluorescens ATCC17400 indicates a capacity to take up iron from a wide range of sources, including different exogenous pyoverdines.

    Science.gov (United States)

    Ye, Lumeng; Matthijs, Sandra; Bodilis, Josselin; Hildebrand, Falk; Raes, Jeroen; Cornelis, Pierre

    2014-08-01

    All fluorescent pseudomonads (Pseudomonas aeruginosa, P. putida, P. fluorescens, P. syringae and others) are known to produce the high-affinity peptidic yellow-green fluorescent siderophore pyoverdine. These siderophores have peptide chains that are quite diverse and more than 50 pyoverdine structures have been elucidated. In the majority of the cases, a Pseudomonas species is also able to produce a second siderophore of lower affinity for iron. Pseudomonas fluorescens ATCC 17400 has been shown to produce a unique second siderophore, (thio)quinolobactin, which has an antimicrobial activity against the phytopathogenic Oomycete Pythium debaryanum. We show that this strain has the capacity to utilize 16 different pyoverdines, suggesting the presence of several ferripyoverdine receptors. Analysis of the draft genome of P. fluorescens ATCC 17400 confirmed the presence of 55 TonB-dependent receptors, the largest so far for Pseudomonas, among which 15 are predicted to be ferripyoverdine receptors (Fpv). Phylogenetic analysis revealed the presence of two different clades containing ferripyoverdine receptors, with sequences similar to the P. aeruginosa type II FpvA forming a separate cluster. Among the other receptors we confirmed the presence of the QbsI (thio)quinolobactin receptor, an ferri-achromobactin and an ornicorrugatin receptor, several catecholate and four putative heme receptors. Twenty five of the receptors genes were found to be associated with genes encoding extracytoplasmic sigma factors (ECF σ) and transmembrane anti-σ sensors.

  3. Iron Metabolism Disturbance in a French Cohort of ALS Patients

    Directory of Open Access Journals (Sweden)

    Charlotte Veyrat-Durebex

    2014-01-01

    Full Text Available Objective. The aim of this study was to assess iron status in a cohort of amyotrophic lateral sclerosis (ALS patients compared to controls in order to evaluate these parameters as a risk factor or a modifying factor of ALS. Methods. We collected serum iron, ferritin, transferrin, total iron-binding capacity, and transferrin saturation coefficient (TSC from 104 ALS patients at the time of diagnosis and from 145 controls. We reported phenotypic characteristics and evolution parameters such as ALSFRS-R and forced vital capacity at diagnosis and after one year of follow-up. In a first step we compared iron status between ALS patients and controls, and then we evaluated the relation between iron status and disease evolution of ALS patients using univariate and multivariate analysis. Results. We observed increased concentrations of serum iron (P=0.002 and ferritin (P<0.0001 and increased TSC (P=0.017 in ALS patients. We also showed an association between markers of iron status and high body weight loss in ALS patients. The multivariate analysis of survival highlighted a significant relation between ferritin level and disease duration (P=0.038. Conclusion. This is the first study showing a higher concentration of serum iron in ALS patients, strengthening the involvement of a deregulation of iron metabolism in ALS.

  4. Impacts of ambient salinity and copper on brown algae: 2. Interactive effects on phenolic pool and assessment of metal binding capacity of phlorotannin.

    Science.gov (United States)

    Connan, Solène; Stengel, Dagmar B

    2011-07-01

    The aim of this study was to establish in laboratory experiments a quantitative link between phenolic pool (production, composition and exudation) in Ascophyllum nodosum and Fucus vesiculosus and their potential to bind metals. Additionally, the copper binding capacity of purified phlorotannin was investigated. A reduction in salinity decreased total phenolic contents, altered phenolic composition by increasing proportion of cell-wall phenolics, and also increased phenolic exudation of the two seaweed species. After 15 days at a salinity of 5, the inhibition of photosynthesis observed previously for A. nodosum coincided with the high exudation of phenolic compounds into the surrounding water of the seaweed tips which resulted in a significant reduction of phenolic contents. Increased copper concentration also reduced total phenolic contents, changed phenolic composition (increase in proportion and level of cell-wall phenolics), and positively affected phenolic exudation of A. nodosum and F. vesiculosus. A decrease in salinity enhanced the copper toxicity and caused the earlier impact on the physiology of seaweed tips. An involvement of phlorotannins in copper binding is also demonstrated; purified phlorotannins from A. nodosum collected from a site with little anthropogenic activity contained all four metals tested. When placed in copper-enriched water, as for the seaweed material, copper contents of the phenolics increased, zinc and cadmium contents decreased, but no change in chromium content was observed. The use of cell-wall phenolic content as biomarker of copper contamination seems promising but needs further investigation. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Impacts of ambient salinity and copper on brown algae: 2. Interactive effects on phenolic pool and assessment of metal binding capacity of phlorotannin

    Energy Technology Data Exchange (ETDEWEB)

    Connan, Solene, E-mail: solene.connan@gmail.com [Botany and Plant Science, School of Natural Sciences, Environmental Change Institute and Martin Ryan Institute, National University of Ireland Galway, Galway (Ireland); Stengel, Dagmar B., E-mail: dagmar.stengel@nuigalway.ie [Botany and Plant Science, School of Natural Sciences, Environmental Change Institute and Martin Ryan Institute, National University of Ireland Galway, Galway (Ireland)

    2011-07-15

    The aim of this study was to establish in laboratory experiments a quantitative link between phenolic pool (production, composition and exudation) in Ascophyllum nodosum and Fucus vesiculosus and their potential to bind metals. Additionally, the copper binding capacity of purified phlorotannin was investigated. A reduction in salinity decreased total phenolic contents, altered phenolic composition by increasing proportion of cell-wall phenolics, and also increased phenolic exudation of the two seaweed species. After 15 days at a salinity of 5, the inhibition of photosynthesis observed previously for A. nodosum coincided with the high exudation of phenolic compounds into the surrounding water of the seaweed tips which resulted in a significant reduction of phenolic contents. Increased copper concentration also reduced total phenolic contents, changed phenolic composition (increase in proportion and level of cell-wall phenolics), and positively affected phenolic exudation of A. nodosum and F. vesiculosus. A decrease in salinity enhanced the copper toxicity and caused the earlier impact on the physiology of seaweed tips. An involvement of phlorotannins in copper binding is also demonstrated; purified phlorotannins from A. nodosum collected from a site with little anthropogenic activity contained all four metals tested. When placed in copper-enriched water, as for the seaweed material, copper contents of the phenolics increased, zinc and cadmium contents decreased, but no change in chromium content was observed. The use of cell-wall phenolic content as biomarker of copper contamination seems promising but needs further investigation.

  6. Thermal Treatment of Iron Oxide Stabilized APC Residues from Waste Incineration and the Effect on Heavy Metal Binding

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Stackpoole, M.; Bender-Koch, C.

    2000-01-01

    Iron oxide stabilized APC residues from MSWI were heat treated at 600°C and 900°C. The thermal treatments resulted in a change in product stability by forcing a transformation in the mineralogical structures of the products. The treatments, moreover, simulated somewhat the natural aging processes...

  7. Association between iron deficiency and febrile seizures.

    Science.gov (United States)

    Papageorgiou, Valia; Vargiami, Euthymia; Kontopoulos, Eleutherios; Kardaras, Panagiotis; Economou, Marina; Athanassiou-Mataxa, Miranta; Kirkham, Fenella; Zafeiriou, Dimitrios I

    2015-09-01

    The relationship between iron status and febrile seizures has been examined in various settings, mainly in the Developing World, with conflicting results. The aim of this study was to investigate any association between iron deficiency and febrile seizures (FS) in European children aged 6-60 months. Prospective, case-control study. Greek population in Thessaloniki. 50 patients with febrile seizures (cases) and 50 controls (children presenting with fever, without seizures). None. Haematologic parameters (haemoglobin concentration, haematocrit, mean corpuscular volume, red cell distribution width), plasma iron, total iron-binding capacity, plasma ferritin, transferrin saturation and soluble transferrin receptors were compared in cases and controls. Plasma ferritin was lower (median [range]: 42.8 (3-285.7) vs 58.3 (21.4-195.3 ng/ml; p = 0.02) and Total Iron Binding Capacity (TIBC) higher (mean [Standard Deviation] 267 [58.9] vs 243 [58.45] μg/dl, p = 0.04) in cases than in controls. Results were similar for 12 complex FS cases (ferritin 30 (3-121 vs 89 (41.8-141.5ng/lL; TIBC 292.92 [68.0] vs 232.08 [36.27] μg/dL). Iron deficiency, defined as ferritin children with febrile seizures have lower Ferritin than those with fever alone, and iron deficiency, but not anaemia, is associated with recurrence. Iron status screening should be considered as routine for children presenting with or at high risk for febrile seizures. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  8. Iron deficiency anaemia among apparently healthy pre-school children in Lagos, Nigeria.

    Science.gov (United States)

    Akodu, Olufemi S; Disu, Elizabeth A; Njokanma, Olisamedua F; Kehinde, Omolara A

    2016-03-01

    Iron deficiency, and specifically iron deficiency anaemia, remains one of the most severe and important nutritional deficiencies in the world today. To estimate the prevalence and associated factors for iron deficiency anaemia among pre-school children in Lagos. The study was conducted from December 2009 to February 2010 at the outpatient clinics of Lagos State University Teaching Hospital, Lagos. Serum iron, total iron binding capacity, transferrin saturation and serum ferritin were assayed in subjects. The primary outcome measured was iron deficiency anaemia established based on the following criteria: hemoglobin iron depletion and this child belonged to the ≤ 2 years age category. None of the recruited subjects had iron deficiency without anaemia. Nine of the study subjects (10.11%) had iron deficiency anaemia. The prevalence of iron deficiency anaemia was significantly higher among younger age group than in the older age group (19.1% Vs 2.1%, p = 0.022). The prevalence of iron deficiency anaemia was significantly higher among subjects with weight-for-age, and weight-for-height Z scores below two standard scores (83.3% and 75.0% respectively, p = iron deficiency anaemia among study subjects was 10.11%. Iron deficiency anaemia was more common in children aged two years and below. Weight-for-age and weight-for-height Z scores below minus two standard scores were strongly associated with iron deficiency anaemia.

  9. Ferrokinetic Parameters and Regulation of Iron Metabolism in Patients with Chronic Inflammatory Bowel Diseases

    Directory of Open Access Journals (Sweden)

    T.Y. Boiko

    2014-12-01

    Full Text Available Article presents parameters of iron metabolism and cytokines (IL-6 and TNF-α in patients with chronic inflammatory bowel diseases (CIBD. The material for the study was the blood of 69 patients with CIBD and anemia and 26 — without anemia. We have studied the features of main ferrokinetic parameters — iron, total iron-binding capacity of serum, transferrin saturation, ferritin, transferrin receptor, erythropoietin, hepcidin depending on hemoglobin level and the type of anemia. The relationship of iron metabolism disorders with the level of proinflammatory cytokines (IL-6 and TNF-α is shown.

  10. In vitro bile acid-binding capacity of dietary fibre sources and their effects with bile acid on broiler chicken performance and lipid digestibility.

    Science.gov (United States)

    Hemati Matin, H R; Shariatmadari, F; Karimi Torshizi, M A; Chiba, L I

    2016-06-01

    A 4 × 2 factorial experiment was conducted to study the effect of feeding diets-containing dietary fibre (DF) sources and a source of bile acid (BA) on growth performance and lipid metabolism. In addition, in vitro BA-binding capacity of fibre sources was investigated. A total of 256 one-d-old male broiler chickens (Ross 308) were assigned to DF sources [maize-soybean meal (control, C), or 30 g/kg of wheat bran (WB), barley bran (BB) or soybean hulls (SH)] and BA (with or without 1.5 g Na-deoxycholate/kg). Each treatment was replicated 4 times with 8 broiler chickens per cage. The highest in vitro BA-binding capacity was observed with BB (8.76 mg/g BB). From 0 to 21 d, with the addition of BA, the average daily feed intake (ADFI) decreased in broiler chickens fed on the C, WB or BB diets, while there was no difference with the SH diet. With added BA, the average daily gain decreased in broiler chickens fed on the C or SH diets, but it did not change in those fed on the other diets. The addition of BA decreased feed conversion ratio (FCR) in broiler chickens fed on the BB or WB diets, but it increased in those fed on the C or SH diets. Interaction results indicated that the apparent ileal digestibility of lipid increased in broiler chickens fed the C and other DF diets with BA compared to those fed the diets without BA. The addition of BA decreased the pancreas lipase activity (PLA) in broiler chickens fed on the C diet compared to those fed the C diet without BA, while no changes observed in those fed the DF diets with or without BA. No interaction was observed in total liver bile acid (TLBA). The WB, BB and SH with little Na-deoxycholate-binding capacity (chickens. The magnitude of improvement in digestibility of lipid with the addition of BA depends on the source of fibre used and the addition of BA in DF diets had little effect on growth performance in young broiler chicken diets.

  11. Desorption of 3,3′-diindolylmethane from imprinted particles: An impact of cross-linker structure on binding capacity and selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Klejn, Dorota; Luliński, Piotr; Maciejewska, Dorota, E-mail: dorota.maciejewska@wum.edu.pl

    2015-11-01

    Here, seven cross-linkers (six polar diacrylates or dimethacrylates of different lengths between double bonds, and one aromatic-divinylbenzene) were used to examine the impact of the cross-linker on binding capacity and selectivity of 3,3′-diindolylmethane (DIM) imprinted material. DIM participates in the suppression of viability of human ovarian and human breast cancer cell lines, but has low bioavailability. The investigations of novel imprinted polymer matrices for improvement of DIM release could allow to utilize not only a potency of DIM but also similar alkaloids, which are the important compounds with pharmacological activity. The bulk, thermal radical copolymerization of the cross-linkers in the presence of 3,3′-diindolylmethane (the template) and allylamine (the functional monomer) in dimethyl sulfoxide or in carbon tetrachloride (porogens) was carried out. The binding capacities of imprinted and non-imprinted polymers were compared, and two polymers (these were prepared using ethylene glycol dimethacrylate and polyethylene glycol dimethacrylate as the cross-linkers) with the highest selectivity and binding capacity were selected to desorption test. The desorption profile of polymer prepared using polyethylene glycol dimethacrylate as the cross-linker revealed sustained release of 3,3′-diindolylmethane, and this system was selected for further optimization of the cross-linker amounts. The morphology and structure of the selected particles were analyzed using SEM micrographs, {sup 13}C CP/MAS NMR spectroscopy, and BET measurements. The desorption of 3,3′-diindolylmethane from poly(allylamine-co-polyethylene glycol dimethacrylate) particles was in accordance with pseudo-second-order kinetics and the simplified Higuchi model indicated the diffusion controlled release of 3,3′-diindolylmethane. - Graphical abstract: Sustained release of 3,3′-diindolylmethane from cavity in imprinted poly(allylamine-co-polyethylene glycol dimethacrylate

  12. The iron-chelating agent picolinic acid enhances transferrin receptors expression in human erythroleukaemic cell lines.

    Science.gov (United States)

    Testa, U; Louache, F; Titeux, M; Thomopoulos, P; Rochant, H

    1985-07-01

    Picolinic acid, a metal chelating molecule, was administered to human erythroleukaemic cell lines (K 562 and HEL) that were grown in serum-containing media. Picolinic acid inhibited both iron uptake and cell growth. Furthermore, picolinic acid was shown to markedly decrease the level of ferritin in the cells. In spite of the inhibition of cell growth, picolinic acid induced a marked increase in the transferrin-binding capacity of the cells. This phenomenon was due to a two-five-fold enhancement of the rate of transferrin receptor biosynthesis. Other iron-chelating compounds, capable of reducing the level of intracellular iron, also elicited a marked enhancement of the transferrin-binding capacity of the cells. However, the addition of iron, as ferric ammonium citrate, in the culture medium elicited a marked increase in the level of ferritin and a strong decrease in the transferrin-binding capacity of the cells. On the basis of these data we propose that a feed-back mechanism is involved in the regulation of transferrin receptors: when the cells accumulate iron they decrease the number of transferrin receptors in order to prevent further accumulation of iron; when no or low iron is available to the cells, the number of transferrin receptors markedly increases as a compensatory mechanism.

  13. A Solid Binding Matrix/Mimic Receptor-Based Sensor System for Trace Level Determination of Iron Using Potential Measurements

    Directory of Open Access Journals (Sweden)

    Ayman H. Kamel

    2011-01-01

    Full Text Available Iron(II-(1,10-phenanthroline complex imprinted membrane was prepared by ionic imprinting technology. In the first step, Fe(II established a coordination linkage with 1,10-phenanthroline and functional monomer 2-vinylpyridine (2-VP. Next, the complex was copolymerized with ethylene glycol dimethacrylate (EGDMA as a crosslinker in the presence of benzoyl peroxide (BPO as an initiator. Potentiometric chemical sensors were designed by dispersing the iron(II-imprinted polymer particles in 2-nitrophenyloctyl ether (o-NPOE plasticizer and then embedded in poly vinyl chloride (PVC matrix. The sensors showed a Nernstian response for [Fe(phen3]2+ with limit of detection 3.15 ng mL−1 and a Nernstian slope of 35.7 mV per decade.

  14. Prolonged antigen presentation by immune complex-binding dendritic cells programs the proliferative capacity of memory CD8 T cells.

    Science.gov (United States)

    León, Beatriz; Ballesteros-Tato, André; Randall, Troy D; Lund, Frances E

    2014-07-28

    The commitment of naive CD8 T cells to effector or memory cell fates can occur after a single day of antigenic stimulation even though virus-derived antigens (Ags) are still presented by DCs long after acute infection is resolved. However, the effects of extended Ag presentation on CD8 T cells are undefined and the mechanisms that regulate prolonged Ag presentation are unknown. We showed that the sustained presentation of two different epitopes from influenza virus by DCs prevented the premature contraction of the primary virus-specific CD8 T cell response. Although prolonged Ag presentation did not alter the number of memory CD8 T cells that developed, it was essential for programming the capacity of these cells to proliferate, produce cytokines, and protect the host after secondary challenge. Importantly, prolonged Ag presentation by DCs was dependent on virus-specific, isotype-switched antibodies (Abs) that facilitated the capture and cross-presentation of viral Ags by FcγR-expressing DCs. Collectively, our results demonstrate that B cells and Abs can regulate the quality and functionality of a subset of antiviral CD8 T cell memory responses and do so by promoting sustained Ag presentation by DCs during the contraction phase of the primary T cell response.

  15. Rye inhibitors of animal alpha-amylases show different specificities, aggregative properties and IgE-binding capacities than their homologues from wheat and barley.

    Science.gov (United States)

    García-Casado, G; Sánchez-Monge, R; López-Otín, C; Salcedo, G

    1994-09-01

    Three new members of the alpha-amylase/trypsin-inhibitor family of cereal endosperm have been isolated from rye. N-terminal amino acid sequence comparison revealed that two of the purified proteins were the rye homologues of the barley monomeric inhibitor (BMAI-1) previously described, while the other rye protein corresponded to one of the subunits of the barley and wheat heterotetrameric inhibitors. However, the inhibitory specificities (active against human salivary alpha-amylase), aggregative behaviours (mainly as dimeric forms) and IgE-binding capacities (not recognized by sera from allergic patients) of the rye inhibitors were clearly different from those of their wheat and barley counterparts. These results indicate that homologous inhibitors may have distinctive properties in different cereal species.

  16. Serum hepcidin levels in Helicobacter pylori-infected children with iron-deficiency anemia: a case-control study.

    Science.gov (United States)

    Azab, Seham F A; Esh, Asmaa M H

    2013-11-01

    Recently, hepcidin, an antimicrobial-like peptide hormone, has evolved as the master regulator of systemic iron homeostasis. Hepcidin integrates signals from diverse physiological inputs, forming a key connection between iron trafficking and response to infection. In this study, we aimed to investigate whether Helicobacter pylori infection modulates serum hepcidin level and response to oral iron therapy in children with iron-deficiency anemia. This was a case-control study including 60 children with iron-deficiency anemia (IDA; 30 H. pylori infected and 30 H. pylori noninfected) and 30 healthy children with comparable age and gender as the control group. Iron parameters including serum iron, ferritin, transferrin, total iron binding capacity, and transferrin saturation and serum hepcidin levels were assessed initially and after 3 months of oral iron therapy for IDA. Compared to the control group, serum hepcidin was significantly lower in H. pylori-noninfected children with IDA (P iron therapy (P iron therapy (P > 0.05). Although hepcidin showed significant positive correlations with serum ferritin, hemoglobin (Hb), iron, and transferrin saturation in noninfected children with IDA (P iron, and transferrin saturation in H. pylori-infected children with IDA (P iron therapy in children with iron-deficiency anemia.

  17. Iron status of female collegiate athletes involved in different sports.

    Science.gov (United States)

    Gropper, Sareen S; Blessing, Daniel; Dunham, Kim; Barksdale, Jeffrey M

    2006-01-01

    Iron status was assessed in 70 female athletes aged 18-25 yr participating in collegiate cross-country track, tennis, softball, swimming, soccer, basketball, and gymnastics. No significant differences in mean hemoglobin, hematocrit, serum iron, total iron-binding capacity, transferrin saturation, and ferritin were found among teams. The mean concentrations of each parameter for each of the teams were within the normal ranges. However, several athletes from different sports had suboptimal iron status indexes. Of 17 athletes with a serum ferritin concentration iron concentrations (athletes failed to consume two-thirds of the Recommended Dietary Allowance for iron and exhibited suboptimal serum concentrations of ferritin, iron, and/or transferrin saturation. Of nine athletes taking iron supplements, one exhibited suboptimal iron status. In summary, nonanemic iron depletion was present among female collegiate athletes involved in many different sports and in all years of participation (freshmen, sophomore, junior, and senior athletes). Female athletes should continue to be individually and routinely evaluated for nutritional deficiencies throughout their collegiate athletic careers.

  18. Effects of training and iron supplementation on iron status of cross-country skiers.

    Science.gov (United States)

    Pattini, A; Schena, F

    1990-12-01

    We have studied the effects of iron treatment on iron deficient cross-country skiers. Kind and duration of their daily training were also considered. Forty-eight athletes were divided in three balanced groups: Group A received 160 mg ferritinic iron/die, Group B received the same amount of iron and 1 gr of ascorbic acid and Group C was untreated. Blood samples were taken at the start, after two months and four months of supplementation. Hematological and iron status parameters were determined. Average training duration was 80 min a day. Running was the most frequent method of training but also roll and country skiing were commonly used. At the initial sample low serum ferritin values were found in all the three groups (Group A = 23.3 micrograms/l, Group B = 20.9 micrograms/l and Group C = 23.5 micrograms/l). After iron treatment serum ferritin increased in Groups A and B (+67.8% and +63.6% respectively) but was slightly reduced in Group C. Serum iron was unchanged and total iron binding capacity decreased following ferritin increase. Ascorbic acid failed to increase iron absorption in Group B. A significant reduction of haptoglobin (-14% and -9% in Group A and B respectively) was also documented. We conclude that cross-country skiers extensively use running in their training and it may be one of the cause of their poor iron status. Ferritinic iron treatment seems to be effective in replacing iron stores in cross-country skiers who underwent heavy training.

  19. Assessment of iron stores in anemic geriatric patients.

    Science.gov (United States)

    Patterson, C; Turpie, I D; Benger, A M

    1985-11-01

    Of patients referred to a geriatric service, 66 were identified who were clearly anemic (hemoglobin less than 12 g in men, less than 11 g in women) but whose cause of anemia was not readily identifiable by noninvasive measures. The difficulty in distinguishing iron deficiency from chronic disease as a cause of anemia by noninvasive means (serum iron, total iron binding capacity, transferrin saturation ratio, and serum ferritin), is highlighted by the poor power of these investigations when compared with bone marrow iron stores. A transferrin saturation ratio of less than 11% and a serum ferritin of less than 45 pg/L serve better than currently accepted values to identify iron deficiency in this population.

  20. PKA Phosphorylates the ATPase Inhibitory Factor 1 and Inactivates Its Capacity to Bind and Inhibit the Mitochondrial H+-ATP Synthase

    Directory of Open Access Journals (Sweden)

    Javier García-Bermúdez

    2015-09-01

    Full Text Available The mitochondrial H+-ATP synthase synthesizes most of cellular ATP requirements by oxidative phosphorylation (OXPHOS. The ATPase Inhibitory Factor 1 (IF1 is known to inhibit the hydrolase activity of the H+-ATP synthase in situations that compromise OXPHOS. Herein, we demonstrate that phosphorylation of S39 in IF1 by mitochondrial protein kinase A abolishes its capacity to bind the H+-ATP synthase. Only dephosphorylated IF1 binds and inhibits both the hydrolase and synthase activities of the enzyme. The phosphorylation status of IF1 regulates the flux of aerobic glycolysis and ATP production through OXPHOS in hypoxia and during the cell cycle. Dephosphorylated IF1 is present in human carcinomas. Remarkably, mouse heart contains a large fraction of dephosphorylated IF1 that becomes phosphorylated and inactivated upon in vivo β-adrenergic stimulation. Overall, we demonstrate the essential function of the phosphorylation of IF1 in regulating energy metabolism and speculate that dephosho-IF1 might play a role in signaling mitohormesis.

  1. Association of Methotrexate with Native and PEGylated PAMAM-G4 Dendrimers: Effect of the PEGylation Degree on the Drug-Loading Capacity and Preferential Binding Sites.

    Science.gov (United States)

    Barraza, Luis F; Jiménez, Verónica A; Alderete, Joel B

    2017-01-12

    PEGylated PAMAM dendrimers (PEG-PAMAM) have been extensively studied as versatile vehicles for drug delivery. Nevertheless, little information has been reported regarding the effect of the PEGylation degree on the drug-loading properties of these systems, aimed at maximizing their performance as drug carrier nanocarrriers. In this work, fully atomistic molecular dynamics (MD) simulations were employed to examine the association of methotrexate (MTX) with native and diversely PEGylated PAMAM-G4 dendrimers, using 2 kDa PEG chains with substitution degrees from 25 to 100% and 100:1 drug:dendrimer ratios to mimic experimental conditions of drug excess in saturated solution. MD results regarding complex stoichiometries and preferential binding sites were compared to experimental data retrieved from aqueous solubility profiles and 2D-NOESY experiments showing an outstanding level of agreement. The maximum theoretical drug loading capacity was achieved by the system with 34% PEGylation (42:1) through the simultaneous complexation of MTX within internal PAMAM-G4 branches and external PEG chains. On the other hand, higher PEGylation degrees were found to be detrimental for drug complexation due to PEG chains crowding on the dendrimer surface. These results provide valuable information to design more efficient PAMAM-based drug nanocarriers and explain the positive effect that partial PEGylation exerts on the drug-loading capacity of PAMAM-G4 over native and fully PEGylated systems.

  2. Formation mechanism and biological activity of novel thiolated human-like collagen iron complex.

    Science.gov (United States)

    Zhu, Chenhui; Liu, Lingyun; Deng, Jianjun; Ma, Xiaoxuan; Hui, Junfeng; Fan, Daidi

    2016-03-01

    To develop an iron supplement that is effectively absorbed and utilized, thiolated human-like collagen was created to improve the iron binding capacity of human-like collagen. A thiolated human-like collagen-iron complex was prepared in a phosphate buffer, and one mole of thiolated human-like collagen-iron possessed approximately 28.83 moles of iron. The characteristics of thiolated human-like collagen-iron were investigated by ultraviolet-visible absorption spectroscopy, Fourier transform infrared spectroscopy, circular dichroism, and differential scanning calorimetry. The results showed that the thiolated human-like collagen-iron complex retained the secondary structure of human-like collagen and had greater thermodynamic stability than human-like collagen, although interactions between iron ions and human-like collagen occurred during the formation of the complex. In addition, to evaluate the bioavailability of thiolated human-like collagen-iron, an in vitro Caco-2 cell model and an in vivo iron deficiency anemia mouse model were employed. The data demonstrated that the thiolated human-like collagen-iron complex exhibited greater bioavailability and was more easily utilized than FeSO4, ferric ammonium citrate, or ferrous glycinate. These results indicated that the thiolated human-like collagen-iron complex is a potential iron supplement in the biomedical field.

  3. Mutagenesis of the aspartic acid ligands in human serum transferrin: lobe-lobe interaction and conformation as revealed by antibody, receptor-binding and iron-release studies.

    Science.gov (United States)

    Mason, A; He, Q Y; Tam, B; MacGillivray, R A; Woodworth, R

    1998-01-01

    Recombinant non-glycosylated human serum transferrin and mutants in which the liganding aspartic acid (D) in one or both lobes was changed to a serine residue (S) were produced in a mammalian cell system and purified from the tissue culture media. Significant downfield shifts of 20, 30, and 45 nm in the absorption maxima were found for the D63S-hTF, D392S-hTF and the double mutant, D63S/D392S-hTF when compared to wild-type hTF. A monoclonal antibody to a sequential epitope in the C-lobe of hTF reported affinity differences between the apo- and iron-forms of each mutant and the control. Cell-binding studies performed under the same buffer conditions used for the antibody work clearly showed that the mutated lobe(s) had an open cleft. It is not clear whether the receptor itself may play a role in promoting the open conformation or whether the iron remains in the cleft. PMID:9461487

  4. Hepcidin and iron metabolism disorders in patients with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Jelić Marija

    2013-01-01

    Full Text Available Bacground/Aim. Hepcidin may play a pathogenetic role in iron metobolism disorders. The aim of this study was to determine the correlation between hepcidin concentration and parameters of iron metabolism in patients with different stage of chronic kidney disease (CKD. Methods. The study involved 104 patients with CKD: 64 on hemodialysis (HD and 40 patients in pre-dialysis stadium (pre-HD with adequate erythropoetin therapy and iron supplementation. The HD group was divided in four subgroups according to the level of serum ferritin (up to 100; 100-199; 200-499 and over 500 ng/mL. Parameters of anemia, iron status, inflamation and hepcidin level were evaluated. Results. The HD patients had a significantly lower eritrocyte count, erythrocytes indexes, hemoglobin and transferrin saturation and significantly higher iron, ferritin, hepcidin and total iron binding capacity (TIBC. The HD subgroups up to 199 ng/mL of serum feritin had lower high-sensitivity Creactive protein (hsCRP, iron and higher unbuffered iron binding capacity (UIBC, transferrin saturation and TIBC compared to the HD subgroups over 200 ng/mL. The lowest and the highest ferritin subgroups had the highest hepcidin level and it showed significant correlation with ferritin. Conclusion. Hepcidin may serve as a marker for better diagnosing and monitoring anemia and iron metabolism disorders in CKD.

  5. Tropical soils in Mato Grosso, Brazil, retain high phosphorus (P) binding capacity after 30 years of intensive fertilization and will remain a P sink for another 50-160 years.

    Science.gov (United States)

    Porder, S.; Roy, E.; Willig, E.; Martinelli, L. A.; Pegorini, L.; Richards, P.; Spera, S. A.; Vazquez, F. F.

    2016-12-01

    Intensification of tropical agriculture is one way to meet increasing global food demand, but tropical soils often require more phosphorus (P) fertilizer than those in the world's traditional breadbaskets. Recent studies from Europe suggest that P fertilizer additions will eventually saturate soil P binding capacity, and can build a soil P bank upon which future crop production can draw. We tested this hypothesis in Mato Grosso, Brazil, where highly mechanized agriculture produces 9% of the world's soy harvest on soils with high P binding capacity. In this region, P fertilizer inputs typically exceed harvests by 10kg P/ha, and our expectation was that total P and available P would increase, and P binding capacity would decrease, with time in cultivation. To test this hypothesis, we measured P availability, binding, and accumulation on 31 fields ranging from 0-31 years in intensive production. We also estimated the number of years in production that would be required to saturate the soils with P, since after that time P additions could be reduced to equal harvest P removal. As expected, our data show increasing P availability, and decreasing P binding capacity, over time. A multiple regression including only soil [SiO2] (a proxy for both mineralogy and texture) and years in production explained 87, 63 and 91% of the observed variation in total P, Bray-extractable P, and P sorption capacity, respectively. However, the effect of [SiO2], and thus texture and mineralogy, was 1.7, 1.2, and 4.9 times more important in predicting our dependent variables than was years in production. Despite fertilizer inputs in excess of harvest removals, the reduction in P binding capacity is slow, and we estimate it will take between 50-160 years for fertilizer inputs to saturate the P binding capacity of these soils. These results suggest that the P tax imposed by high P binding soils in the tropics will impose substantial material costs to tropical farmers in the coming decades, and

  6. Hematological and iron content evolution in exclusively breastfed late-preterm newborns

    Science.gov (United States)

    Yamada, Renato Takeshi; Leone, Cléa Rodrigues

    2014-01-01

    OBJECTIVES: To analyze and compare the evolution of hematological parameters and body iron content between exclusively breastfed late-preterm and term newborns during the first two months of life. METHODS: Cohort study. Weight, length, head circumference, body mass index, hemoglobin, hematocrit, reticulocytes, total iron-binding capacity, transferrin saturation, serum iron and ferritin were measured in 25 late-preterm and 21 term newborns (at birth and at one and two months of age) who were exclusively breastfed. Statistical analysis: Kolmogorov-Smirnov test, one-way ANOVA or Kruskal-Wallis test; and Student's t-test or Mann-Whitney test. Significance: p<0.05. RESULTS: The corrected gestational ages of the late-preterm infants were 39.98 weeks at one month of life and 44.53 weeks at two months. Anthropometric measures and the body mass index increased over time (p<0.001) and hemoglobin, hematocrit, reticulocytes and body iron content decreased (p<0.001). Late-preterm infants at term corrected gestational age had reduced hemoglobin, hematocrit and reticulocyte concentrations, and reduced total iron-binding capacity (p<0.001) and serum iron (p = 0.0034) compared with values observed in term newborns at birth. Late-preterm newborns at a corrected gestational age of one month post-term had hemoglobin (p = 0.0002), hematocrit (p = 0.0008), iron (p<0.0001) and transferrin saturation (p<0.001) levels lower than those of term newborns at one month of age and a higher total iron-binding capacity (p = 0.0018). Ferritin did not differ between the groups. CONCLUSION: Exclusively breastfed late-preterm newborns presented greater reductions in hemoglobin/hematocrit and lower iron stores at a corrected gestational age of one month post-term than did term newborns, suggesting specific iron supplementation needs. PMID:25627989

  7. Hematological and iron content evolution in exclusively breastfed late-preterm newborns

    Directory of Open Access Journals (Sweden)

    Renato Takeshi Yamada

    2014-01-01

    Full Text Available OBJECTIVES: To analyze and compare the evolution of hematological parameters and body iron content between exclusively breastfed late-preterm and term newborns during the first two months of life. METHODS: Cohort study. Weight, length, head circumference, body mass index, hemoglobin, hematocrit, reticulocytes, total iron-binding capacity, transferrin saturation, serum iron and ferritin were measured in 25 late-preterm and 21 term newborns (at birth and at one and two months of age who were exclusively breastfed. Statistical analysis: Kolmogorov-Smirnov test, one-way ANOVA or Kruskal-Wallis test; and Student's t-test or Mann-Whitney test. Significance: p<0.05. RESULTS: The corrected gestational ages of the late-preterm infants were 39.98 weeks at one month of life and 44.53 weeks at two months. Anthropometric measures and the body mass index increased over time (p<0.001 and hemoglobin, hematocrit, reticulocytes and body iron content decreased (p<0.001. Late-preterm infants at term corrected gestational age had reduced hemoglobin, hematocrit and reticulocyte concentrations, and reduced total iron-binding capacity (p<0.001 and serum iron (p = 0.0034 compared with values observed in term newborns at birth. Late-preterm newborns at a corrected gestational age of one month post-term had hemoglobin (p = 0.0002, hematocrit (p = 0.0008, iron (p<0.0001 and transferrin saturation (p<0.001 levels lower than those of term newborns at one month of age and a higher total iron-binding capacity (p = 0.0018. Ferritin did not differ between the groups. CONCLUSION: Exclusively breastfed late-preterm newborns presented greater reductions in hemoglobin/hematocrit and lower iron stores at a corrected gestational age of one month post-term than did term newborns, suggesting specific iron supplementation needs.

  8. DNA binding and cleavage activity by a mononuclear iron(II)Schiff base complex: Synthesis and structural characterization

    Indian Academy of Sciences (India)

    Abhijit Pal; Bhaskar Biswas; Merry Mitra; Subramaniyam Rajalakshmi; Chandra Shekhar Purohit; Soumitra Hazra; Gopinatha Suresh Kumar; Balachandran Unni Nair; Rajarshi Ghosh

    2013-09-01

    Synthesis and characterization of a mononuclear Fe(II) compound [Fe(L)](ClO4)2 (1) [L = N-(1-pyridin-2-yl-phenylidene)-N'-[2-({2-[(1-pyridin-2-ylphenylidene)amino]ethyl}amino)ethyl] ethane-1,2-diamine] (1) is reported. 1 crystallizes in P-1 space group with a = 11.9241(3) Å, b = 12.1994(3) Å and c = 13.0622(4) Å. The binding property of the complex with DNA has been investigated using absorption and emission studies, thermal melting, viscosity experiments and circular dichroism studies. The binding constant (b) and the linear Stern-Volmer quenching constant (sv) of the complex have been determined as 3.5 × 103M-1 and 2.73 × 104M-1, respectively. Spectroscopic and hydrodynamic investigations revealed intercalative mode of binding of 1 with DNA. 1 is also found to induce oxidative cleavage of the supercoiled pUC 18 DNA to its nicked circular form in a concentration dependent manner.

  9. The distal pocket histidine residue in horse heart myoglobin directs the O-binding mode of nitrite to the heme iron.

    Science.gov (United States)

    Yi, Jun; Heinecke, Julie; Tan, Hui; Ford, Peter C; Richter-Addo, George B

    2009-12-23

    It is now well-established that mammalian heme proteins are reactive with various nitrogen oxide species and that these reactions may play significant roles in mammalian physiology. For example, the ferrous heme protein myoglobin (Mb) has been shown to reduce nitrite (NO(2)(-)) to nitric oxide (NO) under hypoxic conditions. We demonstrate here that the distal pocket histidine residue (His64) of horse heart metMb(III) (i.e., ferric Mb(III)) has marked effects on the mode of nitrite ion coordination to the iron center. X-ray crystal structures were determined for the mutant proteins metMb(III) H64V (2.0 A resolution) and its nitrite ion adduct metMb(III) H64V-nitrite (1.95 A resolution), and metMb(III) H64V/V67R (1.9 A resolution) and its nitrite ion adduct metMb(III) H64V/V67R-nitrite (2.0 A resolution). These are compared to the known structures of wild-type (wt) hh metMb(III) and its nitrite ion adduct hh metMb(III)-nitrite, which binds NO(2)(-) via an O-atom in a trans-FeONO configuration. Unlike wt metMb(III), no axial H(2)O is evident in either of the metMb(III) mutant structures. In the ferric H64V-nitrite structure, replacement of the distal His residue with Val alters the binding mode of nitrite from the nitrito (O-binding) form in the wild-type protein to a weakly bound nitro (N-binding) form. Reintroducing a H-bonding residue in the H64V/V67R double mutant restores the O-binding mode of nitrite. We have also examined the effects of these mutations on reactivities of the metMb(III)s with cysteine as a reducing agent and of the (ferrous) Mb(II)s with nitrite ion under anaerobic conditions. The Mb(II)s were generated by reduction of the Mb(III) precursors in a second-order reaction with cysteine, the rate constants for this step following the order H64V/V67R > H64V > wt. The rate constants for the oxidation of the Mb(II)s by nitrite (giving NO as the other product) follow the order wt > H64V/V67R > H64V and suggest a significant role of the distal pocket H

  10. Training for cross-country skiing and iron status.

    Science.gov (United States)

    Haymes, E M; Puhl, J L; Temples, T E

    1986-04-01

    Effects of iron supplements and training for cross-country skiing on hematological and iron status were studied in nine men and ten women from the U. S. Nordic ski team. Four men and five women received a multiple vitamin, multiple mineral supplement containing 18 mg iron for 8 months while five men and five women received a placebo. Fasting blood samples were taken from all skiers prior to supplementation (May) and in August, November, and January. Hemoglobin, hematocrit, plasma iron, total iron binding capacity (TIBC), percentage of transferrin saturation, serum ferritin, free erythrocyte porphyrin, and haptoglobin were measured on each sample. Hemoglobin, hematocrit, and TIBC were higher in November when both men and women skiers trained at altitude than in August. In January TIBC was further increased, haptoglobin was increased, hemoglobin for the men fell below May levels, and hematocrit returned to May levels. Skiers receiving iron had lower TIBC levels in November and January than the placebo group. Six women and two men had ferritin levels below 28 ng X ml-1, which suggests prelatent iron deficiency. Free erythrocyte porphyrin levels above 100 micrograms X dl-1 RBC were found in all skiers at some point during training. The results suggest that multivitamin, multimineral supplements containing iron have little effect on the iron status of cross-country skiers.

  11. Effect of Iron Enriched Bread Intake on the Oxidative Stress Indices in Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    Sharareh Heidari

    2016-08-01

    Full Text Available Background Contrary to the proven benefits of iron, few concerns in producing the oxidative stress is remained problematic. Objectives The aim of the study was to evaluate the oxidative stress in the male Wistar rats fed bread supplemented with iron in different doses i.e., 35 (basic, 70 (two fold, 140 (four fold, and 210 mg/kg (six fold with or without NaHCO3 (250 mg/kg. Methods In this experimental study Iron, ceruloplasmin, ferritin, total iron binding capacity (TIBC, albumin, total protein, uric acid and plasma superoxide dismutase (SOD, glutathione peroxidase (GPX, catalase (CAT, malondialdehyde (MDA, and total antioxidant capacity (TAC, were evaluated in 30 rats at the first and last day of the experiment (day 30. In addition, phytic acid levels were detected in all baked breads. The data were analyzed by ANOVA and t test procedure though SPSS statistical software version 20. Results Serum iron level in rats that received basic level of iron plus NaHCO3 decreased significantly in the last day of the trial. Higher level of serum iron was seen in rats that received iron twofold, fourfold and sixfold and rats that received iron fourfold plus NaHCO3. Serum ceruloplasmin and ferritin in groups of rats that received fourfold level of iron plus NaHCO3 and rats that received iron sixfold showed a significant increase (P ≤ 0.05. Serum total protein and uric acid in rats that received basic level of iron plus NaHCO3 and rats that received twofold level of iron showed a significant decrease. Serum total protein levels in rats that received fourfold level of iron showed a significant decrease. Bread with NaHCO3 showed higher phytic acid levels than other groups. Conclusions These results indicate that oxidative stress was not induced, whereas some antioxidant activities were significantly changed in rats that received iron-enriched bread.

  12. Serum fibroblast growth factor 23, serum iron and bone mineral density in premenopausal women.

    Science.gov (United States)

    Imel, Erik A; Liu, Ziyue; McQueen, Amie K; Acton, Dena; Acton, Anthony; Padgett, Leah R; Peacock, Munro; Econs, Michael J

    2016-05-01

    Fibroblast growth factor 23 (FGF23) circulates as active protein and inactive fragments. Low iron status increases FGF23 gene expression, and iron deficiency is common. We hypothesized that in healthy premenopausal women, serum iron influences C-terminal and intact FGF23 concentrations, and that iron and FGF23 associate with bone mineral density (BMD). Serum iron, iron binding capacity, percent iron saturation, phosphorus, and other biochemistries were measured in stored fasting samples from healthy premenopausal white (n=1898) and black women (n=994), age 20-55years. Serum C-terminal and intact FGF23 were measured in a subset (1631 white and 296 black women). BMD was measured at the lumbar spine and femur neck. Serum phosphorus, calcium, alkaline phosphatase and creatinine were lower in white women than black women (piron (piron. C-terminal FGF23 correlated inversely with iron (white women r=-0.134, piron iron predicted changes in C-terminal FGF23. Spine BMD correlated with iron negatively (r=-0.076, piron negatively (r=-0.119, piron did not relate to intact FGF23, but was inversely related to C-terminal FGF23. Intact FGF23 correlated with serum phosphorus. In weight-adjusted models, BMD was not related to intact FGF23, C-terminal FGF23 or iron. The influence of iron on FGF23 gene expression is not important in determining bone density in healthy premenopausal women.

  13. The capacity of Listeria monocytogenes mutants with in-frame deletions in putative ATP-binding cassette transporters to form biofilms and comparison with the wild type

    Directory of Open Access Journals (Sweden)

    Marina Ceruso

    2014-02-01

    Full Text Available Listeria monocytogenes (Lm is a food-borne pathogen responsible for human listeriosis, an invasive infection with high mortality rates. Lm has developed efficient strategies for survival under stress conditions such as starvation and wide variations in temperature, pH, and osmolarity. Therefore, Lm can survive in food under multiple stress conditions. Detailed studies to determine the mode of action of this pathogen for survival under stress conditions are important to control Lm in food. It has been shown that genes encoding for ATP-binding cassette (ABC transporters are induced in Lm in food, in particular under stress conditions. Previous studies showed that these genes are involved in sensitivity to nisin, acids, and salt. The aim of this study was to determine the involvement of some ABC transporters in biofilm formation. Therefore, deletion mutants of ABC transporter genes (LMOf2365_1875 and LMOf2365_1877 were created in Lm F2365, and then were compared to the wild type for their capacity to form biofilms. Lm strain F2365 was chosen as reference since the genome is fully sequenced and furthermore this strain is particularly involved in food-borne outbreaks of listeriosis. Our results showed that DLMOf2365_1875 had an increased capacity to form biofilms compared to the wild type, indicating that LMOf2365_1875 negatively regulates biofilm formation. A deeper knowledge on the ability to form biofilms in these mutants may help in the development of intervention strategies to control Lm in food and in the environment.

  14. The Capacity of Listeria Monocytogenes Mutants with In-Frame Deletions in Putative ATP-Binding Cassette Transporters to form Biofilms and Comparison with the Wild Type

    Science.gov (United States)

    Ceruso, Marina; Fratamico, Pina; Chirollo, Claudia; Taglialatela, Rosanna; Cortesi, Maria Luisa

    2014-01-01

    Listeria monocytogenes (Lm) is a food-borne pathogen responsible for human listeriosis, an invasive infection with high mortality rates. Lm has developed efficient strategies for survival under stress conditions such as starvation and wide variations in temperature, pH, and osmolarity. Therefore, Lm can survive in food under multiple stress conditions. Detailed studies to determine the mode of action of this pathogen for survival under stress conditions are important to control Lm in food. It has been shown that genes encoding for ATP-binding cassette (ABC) transporters are induced in Lm in food, in particular under stress conditions. Previous studies showed that these genes are involved in sensitivity to nisin, acids, and salt. The aim of this study was to determine the involvement of some ABC transporters in biofilm formation. Therefore, deletion mutants of ABC transporter genes (LMOf2365_1875 and LMOf2365_1877) were created in Lm F2365, and then were compared to the wild type for their capacity to form biofilms. Lm strain F2365 was chosen as reference since the genome is fully sequenced and furthermore this strain is particularly involved in food-borne outbreaks of listeriosis. Our results showed that ΔLMOf2365_1875 had an increased capacity to form biofilms compared to the wild type, indicating that LMOf2365_1875 negatively regulates biofilm formation. A deeper knowledge on the ability to form biofilms in these mutants may help in the development of intervention strategies to control Lm in food and in the environment. PMID:27800311

  15. Effect of a six-month iron-zinc fortified milk supplementation on nutritional status, physical capacity and speed learning process in Indonesian underweight schoolchildren: randomized, placebo-controlled

    Directory of Open Access Journals (Sweden)

    Saptawati Bardosono

    2009-09-01

    Full Text Available Aim to evaluated the effect of milk supplementation enriched with iron and zinc on indicators of growth, physical capacity and cognitive performance in underweight school-children.Method Two-armed, randomized controlled double-blind trial was performed in several primary schools in Jakarta and Surakarta, Indonesia. A total of 245 underweight schoolchildren aged 7-9 years living in urban poor areas of Jakarta and Solo were randomly allocated to receive two cups of iron-zinc fortified-milk (n = 121 or non-iron-zinc fortified milk (n= 124 supplementation daily for six months. Biochemical indicators, anthropometric indices, physical capacity and cognitive performance were measured at before and after the supplementation.Results The study shows that between the fortified and non-fortified milk group, there was no significant different in haemoglobin increase (0.01 + 0.96 mg/dL versus 0.17 + 0.81 mg/dL nor serum ferritin increase (12.77 + 25.50 mcg/dL versus 14.99 + 29.56 mcg/dL. Unexpectedly, decreased in serum zinc was found in both groups (3.01 + 3.24 mMol/dL and 3.12 + 3.71 mMol/dL. There was significant higher increment (P=0.045 in body weight among the fortified milk group (1.31 + 0.69 kg as compared to the non-fortified group (1.13 + 0.69 kg. Consistently, there was significant increase (P=0.025 in the indicator of underweight (WAZ among the fortified milk group (1.47 + 0.50 as compared to the non-fortified group (1.33 + 0.47. There was significant improvement (P=0.001 of cognitive performance, i.e. coding test-score among the fortified group (12.74 + 11.76 as compared to the non-fortified group (8.31 + 9.60, but there was no significant difference found in the improvement of physical capacity score in both groups (10323.77 + 9253.83 versus 8435.94 + 8824.55.Conclusion Among underweight schoolchildren aged 7-9 y, supplementation of milk fortified with iron and zinc can provide better growth, and better speed processing of learning ability

  16. Correlation between vivax malaria infection and iron deficiency in children

    Directory of Open Access Journals (Sweden)

    Desmansyah Desmansyah

    2016-07-01

    Full Text Available Background Iron deficiency is considered to be a major public health problem around the world due to its high prevalence as well as its effect on growth, development, and infection-resistance in children. In malaria-endemic areas, malaria infection is thought to contribute to the occurrence of iron deficiency, by means of hepcidin and hemolysis mechanisms. Objective To assess the prevalence of asymptomatic vivax malaria, compare hemoglobin levels and iron status parameters between vivax malaria-infected and uninfected children, assess the prevalence of iron deficiency, and evaluate a possible correlation between vivax malaria infection and iron deficiency. Methods This cross-sectional study was conducted from February to April 2013 at Sanana City of Sula Islands District, North Maluku. Six parameters were evaluated in 5-11-year-old children: malaria parasite infection, hemoglobin level, serum iron concentration, total iron-binding capacity (TIBC, serum transferrin saturation, and serum ferritin concentration. Results Among 296 children aged 5-11 years, 75 (25.3% were infected with Plasmodium vivax. In infected children, hemoglobin, serum iron, transferrin saturation, TIBC and serum ferritin were significantly lower than in non-infected children (P<0.01. Using a serum ferritin cut-off of <15 μg/dL, 142 (48.0% of the children were found to be iron deficient. There was a strong correlation between vivax malaria infection and iron deficiency (OR 3.573; 95%CI 2.03-6.29. ConclusionThe prevalence of asymptomatic vivax malaria infection was 25.3%. The hemoglobin level and iron status parameters in vivax malaria-infected subjects were significantly lower than in uninfected children. The prevalence of iron deficiency was 48.0% for all study subjects. Malaria vivax infection was correlated with iron deficiency in 5-11-year-old children at Sanana City.

  17. Sustainability of the effects of medicinal iron and iron rich food supplementation on haemoglobin, intelligence quotient and growth of school aged girls

    Directory of Open Access Journals (Sweden)

    Monika Jain

    2014-12-01

    Full Text Available Anaemia in school aged girls is an important but neglected issue. Since iron supplementation programmes have had little reported success in reducing anaemia, interest is turning to food based approaches that have higher potential for achieving far reaching benefits. The purpose of the study was to observe sustainability of the effect of iron and food supplementation on haemoglobin (Hb, intelligence quotient (IQ and growth of the subjects. At baseline, estimation of haemoglobin (Hb, red cell indices, serum iron, total iron binding capacity, serum transferrin saturation and serum ferritin was done. IQ, weight and height were measured using standard procedures. Anaemic subjectswere divided into three groups, viz., (i twice weekly supplementation of iron folic acid syrup (53 mg iron/week; (ii daily supplementation of 4 niger seed and defatted soyaflour biscuits plus 2 lemons (45 mg iron/week and (iii control. Non anaemic group(NAC was not intervened. Endline data was collected after 120 days. Follow up for Hb, IQ, weight and height was done 4 months after cessation of supplementation. The prevalence of anaemia was 77% in the study population; 46% subjects had mild anaemia and 32% had moderate anaemia. Iron status was lower in anaemic subjects (p<0.001.Iron supplementation was more effective in raising Hb and building iron stores than iron rich food supplementation. Iron supplementation improved IQ but did not bring about catch up of anaemics to non anaemics. Iron rich food supplementation was better than medicinal iron in promoting growth in anaemic girls. The impact of iron rich food supplementation on Hb, IQ and growth sustained for 4 months while that of medicinal iron did not. Effects of food supplementation are sustainable for 4 months, therefore, this strategy holds more potential to control anaemia, in school aged girls.

  18. In vivo binding of radiocesium by two forms of Prussian blue and by ammonium iron hexacyanoferrate (II).

    Science.gov (United States)

    Dresow, B; Nielsen, P; Fischer, R; Pfau, A A; Heinrich, H H

    1993-01-01

    The effect of two forms of Prussian blue, soluble K3 Fe[Fe(CN)6] and insoluble Fe4[Fe(CN)6]3, and of ammonium iron hexacyanoferrate (II) (NH4Fe[Fe(CN)6] on intestinal radiocesium absorption was investigated in rats, pigs, and humans. In rats 5 mg of antidote administered 2 min before 134Cs tracer reduced radiocesium absorption to 2.4-6.3% of the oral dose. In pigs fed with Chernobyl-contaminated whey under normal feeding conditions for a 27 day period, radiocesium activity concentration was reduced from 360 Bq/kg in control animals to 10-30 Bq/kg by 5 g antidote/d. In man 1 g of oral Prussian blue diminished the cesium absorption from a 134Cs-labelled test meal to 5.6-6.4% of the controls. The inhibitory effects of colloidally soluble K3 Fe[Fe(CN)6] and of (NH4Fe[Fe(CN)6] were similar with slightly less inhibition by the insoluble Fe4[Fe(CN)6]3.

  19. Attenuation of serum ferritin and iron burden by intake of antioxidants in beta thalassemia major.

    Science.gov (United States)

    Bhagat, Sonali S; Sarkar, Purnima Dey; Suryakar, Adinath N; Padalkar, Ramchandra K; Ghone, Rahul A; Patil, Sangita M; Hundekar, Prakash S

    2013-01-01

    It has been anticipated that iron and ferritin burden in patients with beta thalassemia major is associated with enhanced free radical formation and blemished antioxidant defense system. The goal of study was to scrutinize impact of serum iron, total iron binding capacity (TIBC), ferritin and erythrocyte catalase in patients with beta thalassemia major. 140 beta thalassemia major patients were studied before and after supplementation of antioxidants for one month, and status was compared with 140 age and sex matched healthy controls. A significant elevation was found in the levels of serum iron and ferritin (P serum TIBC concentration increased marginally while iron and ferritin were decreased marginally (P > 0.05) when compared with controls and baselines values. Beta thalassemia major children receive multiple blood transfusions, and are at risk of secondary iron overload induced oxidative stress. These effects may be help to minimize with supplementation of antioxidants.

  20. The key to the extraordinary thermal stability of P. furiosus holo-rubredoxin: iron binding-guided packing of a core aromatic cluster responsible for high kinetic stability of the native structure.

    Science.gov (United States)

    Prakash, Satya; Sundd, Monica; Guptasarma, Purnananda

    2014-01-01

    Pyrococcus furiosus rubredoxin (PfRd), a small, monomeric, 53 residues-long, iron-containing, electron-transfer protein of known structure is sometimes referred to as being the most structurally-stable protein known to man. Here, using a combination of mutational and spectroscopic (CD, fluorescence, and NMR) studies of differently made holo- and apo-forms of PfRd, we demonstrate that it is not the presence of iron, or even the folding of the PfRd chain into a compact well-folded structure that causes holo-PfRd to display its extraordinary thermal stability, but rather the correct iron binding-guided packing of certain residues (specifically, Trp3, Phe29, Trp36, and also Tyr10) within a tight aromatic cluster of six residues in PfRd's hydrophobic core. Binding of the iron atom appears to play a remarkable role in determining subtle details of residue packing, forcing the chain to form a hyper-thermally stable native structure which is kinetically stable enough to survive (subsequent) removal of iron. On the other hand, failure to bind iron causes the same chain to adopt an equally well-folded native-like structure which, however, has a differently-packed aromatic cluster in its core, causing it to be only as stable as any other ordinary mesophile-derived rubredoxin. Our studies demonstrate, perhaps for the very first time ever that hyperthermal stability in proteins can owe to subtle differences in residue packing vis a vis mesostable proteins, without there being any underlying differences in either amino acid sequence, or bound ligand status.

  1. In Vitro binding capacity of zeolite A to calcium, phosphorus and magnesium in rumen fluid as influenced by changes in pH

    DEFF Research Database (Denmark)

    Thilsing, Trine; Jørgensen, Rolf Jess; Poulsen, H.D.

    2006-01-01

    An in vitro experiment was designed to mimic the transport of ingested zeolite A in the forestomachs and proximal part of the small intestine so as to evaluate the binding capacity of zeolite A to Ca, P and Mg as influenced by changes in pH. This was done by incubation of rumen fluid solutions...... with and without zeolite, as well as varying the content of Ca and/or P. The pH was lowered by addition of HCl so as to mimic abomasal conditions, followed by subsequent HCO3- addition to mimic small intestinal pH. Rumen fluid samples were taken at strategic time points in the experiment. All samples were...... centrifuged and the supernatant analysed for Ca, P and Mg as indicators of the amount of unbound mineral. The addition of zeolite to rumen fluid solutions reduced the amount of supernatant Ca and Mg at rumen pH, whereas the level of P was not reduced. After adding HCl, a large proportion of the zeolite...

  2. Mutants of the major ryegrass pollen allergen, Lol p 5, with reduced IgE-binding capacity: candidates for grass pollen-specific immunotherapy.

    Science.gov (United States)

    Swoboda, Ines; De Weerd, Nicole; Bhalla, Prem L; Niederberger, Verena; Sperr, W R; Valent, Peter; Kahlert, Helga; Fiebig, Helmut; Verdino, Petra; Keller, Walter; Ebner, Christof; Spitzauer, Susanne; Valenta, Rudolf; Singh, Mohan B

    2002-01-01

    More than 400 million individuals are sensitized to grass pollen allergens. Group 5 allergens represent the most potent grass pollen allergens recognized by more than 80 % of grass pollen allergic patients. The aim of our study was to reduce the allergenic activity of group 5 allergens for specific immunotherapy of grass pollen allergy. Based on B- and T-cell epitope mapping studies and on sequence comparison of group 5 allergens from different grasses, point mutations were introduced by site-directed mutagenesis in highly conserved sequence domains of Lol p 5, the group 5 allergen from ryegrass. We obtained Lol p 5 mutants with low IgE-binding capacity and reduced allergenic activity as determined by basophil histamine release and by skin prick testing in allergic patients. Circular dichroism analysis showed that these mutants exhibited an overall structural fold similar to the recombinant Lol p 5 wild-type allergen. In addition, Lol p 5 mutants retained the ability to induce proliferation of group 5 allergen-specific T cell lines and clones. Our results demonstrate that a few point mutations in the Lol p 5 sequence yield mutants with reduced allergenic activity that represent potential vaccine candidates for immunotherapy of grass pollen allergy.

  3. Molecular cloning and preliminary function study of iron responsive element binding protein 1 gene from cypermethrin-resistant Culex pipiens pallens

    Directory of Open Access Journals (Sweden)

    Tan Wenbin

    2011-11-01

    Full Text Available Abstract Background Insecticide resistance jeopardizes the control of mosquito populations and mosquito-borne disease control, which creates a major public health concern. Two-dimensional electrophoresis identified one protein segment with high sequence homology to part of Aedes aegypti iron-responsive element binding protein (IRE-BP. Method RT-PCR and RACE (rapid amplification of cDNA end were used to clone a cDNA encoding full length IRE-BP 1. Real-time quantitative RT-PCR was used to evaluate the transcriptional level changes in the Cr-IRE strain Aedes aegypti compared to the susceptible strain of Cx. pipiens pallens. The expression profile of the gene was established in the mosquito life cycle. Methyl tritiated thymidine (3H-TdR was used to observe the cypermethrin resistance changes in C6/36 cells containing the stably transfected IRE-BP 1 gene of Cx. pipiens pallens. Results The complete sequence of iron responsive element binding protein 1 (IRE-BP 1 has been cloned from the cypermethrin-resistant strain of Culex pipiens pallens (Cr-IRE strain. Quantitative RT-PCR analysis indicated that the IRE-BP 1 transcription level was 6.7 times higher in the Cr-IRE strain than in the susceptible strain of 4th instar larvae. The IRE-BP 1 expression was also found to be consistently higher throughout the life cycle of the Cr-IRE strain. A protein of predicted size 109.4 kDa has been detected by Western blotting in IRE-BP 1-transfected mosquito C6/36 cells. These IRE-BP 1-transfected cells also showed enhanced cypermethrin resistance compared to null-transfected or plasmid vector-transfected cells as determined by 3H-TdR incorporation. Conclusion IRE-BP 1 is expressed at higher levels in the Cr-IRE strain, and may confer some insecticide resistance in Cx. pipiens pallens.

  4. Metal based pharmacologically active agents: Synthesis, structural characterization, molecular modeling, CT-DNA binding studies and in vitro antimicrobial screening of iron(II) bromosalicylidene amino acid chelates

    Science.gov (United States)

    Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.; Ismael, Mohamed; Seleem, Amin Abdou

    2014-01-01

    In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine (arg)). The structure of the investigated iron(II) complexes was elucidated using elemental analyses, infrared, ultraviolet-visible, thermogravimetric analysis, as well as conductivity and magnetic susceptibility measurements. Moreover, the stoichiometry and the stability constants of the prepared complexes have been determined spectrophotometrically. The results suggest that 5-bromosalicylaldehyde amino acid Schiff bases (bs:aa) behave as dibasic tridentate ONO ligands and coordinate to Fe(II) in octahedral geometry according to the general formula [Fe(bs:aa)2]ṡnH2O. The conductivity values between 37 and 64 ohm-1 mol-1 cm2 in ethanol imply the presence of nonelectrolyte species. The structure of the complexes was validated using quantum mechanics calculations based on accurate DFT methods. Geometry optimization of the Fe-Schiff base amino acid complexes showed that all complexes had octahedral coordination. In addition, the interaction of these complexes with (CT-DNA) was investigated at pH = 7.2, by using UV-vis absorption, viscosity and agarose gel electrophoresis measurements. Results indicated that the investigated complexes strongly bind to calf thymus DNA via intercalative mode and showed a different DNA binding according to the sequence: bsari > bshi > bsali > bsasi > bsphali. Moreover, the prepared compounds are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus

  5. Preparation and Bioavailability Analysis of Ferrous Bis Alanine Chelate as a New Micronutrient for Treatment of Iron Deficiency Anemia

    Science.gov (United States)

    Zargaran, Marzieh; Saadat, Ebrahim; Dinarvand, Rassoul; Sharifzadeh, Mohammad; Dorkoosh, Farid

    2016-01-01

    Purpose: One of the most nutritional disorders around the world is iron deficiency. A novel iron compound was synthesized by chelating ferrous ions with alanine for prevention and treatment of iron deficiency anemia. Methods: The newly synthesized compound was characterized both qualitatively and quantitatively by Fourier Transform Infrared (FT-IR) spectroscopy. The bioavailability of newly synthesized iron micronutrient was evaluated in four groups of Wistar rats. The group I was a negative control group and the other three groups received three different iron formulations. After 14 days, the blood samples were taken and analyzed accordingly. Results: Calculations showed that more than 91.8% of iron was incorporated in the chelate formulation. In vivo studies showed that serum iron, total iron binding capacity and hemoglobin concentrations were significantly increased in group IV, which received ferrous bis alanine chelate compared with the negative control group (p<0.05) and also group II, which received ferrous sulfate.7H2O (p<0.05). It indicates that the new formulation considerably improves the blood iron status compared with the conventional iron compounds. There were no significant differences (p<0.05) in the serum iron between group IV and group III, which received ferrous bis glycine. Conclusion: The results showed better bioavailability of ferrous bis alanine as a new micronutrient for treatment of iron deficiency anemia in comparison with ferrous sulfate. Ferrous bis alanine could be considered as a suitable supplement for prevention and treatment of iron deficiency anemia. PMID:27766225

  6. Gastric Helicobacter infection induces iron deficiency in the INS-GAS mouse.

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    Melanie J Thomson

    Full Text Available There is increasing evidence from clinical and population studies for a role of H. pylori infection in the aetiology of iron deficiency. Rodent models of Helicobacter infection are helpful for investigating any causal links and mechanisms of iron deficiency in the host. The aim of this study was to investigate the effects of gastric Helicobacter infection on iron deficiency and host iron metabolism/transport gene expression in hypergastrinemic INS-GAS mice. INS-GAS mice were infected with Helicobacter felis for 3, 6 and 9 months. At post mortem, blood was taken for assessment of iron status and gastric mucosa for pathology, immunohistology and analysis of gene expression. Chronic Helicobacter infection of INS- GAS mice resulted in decreased serum iron, transferrin saturation and hypoferritinemia and increased Total iron binding capacity (TIBC. Decreased serum iron concentrations were associated with a concomitant reduction in the number of parietal cells, strengthening the association between hypochlorhydria and gastric Helicobacter-induced iron deficiency. Infection with H. felis for nine months was associated with decreased gastric expression of iron metabolism regulators hepcidin, Bmp4 and Bmp6 but increased expression of Ferroportin 1, the iron efflux protein, iron absorption genes such as Divalent metal transporter 1, Transferrin receptor 1 and also Lcn2 a siderophore-binding protein. The INS-GAS mouse is therefore a useful model for studying Helicobacter-induced iron deficiency. Furthermore, the marked changes in expression of gastric iron transporters following Helicobacter infection may be relevant to the more rapid development of carcinogenesis in the Helicobacter infected INS-GAS model.

  7. Gastric Helicobacter infection induces iron deficiency in the INS-GAS mouse.

    Science.gov (United States)

    Thomson, Melanie J; Pritchard, D Mark; Boxall, Sally A; Abuderman, Abdul A; Williams, Jonathan M; Varro, Andrea; Crabtree, Jean E

    2012-01-01

    There is increasing evidence from clinical and population studies for a role of H. pylori infection in the aetiology of iron deficiency. Rodent models of Helicobacter infection are helpful for investigating any causal links and mechanisms of iron deficiency in the host. The aim of this study was to investigate the effects of gastric Helicobacter infection on iron deficiency and host iron metabolism/transport gene expression in hypergastrinemic INS-GAS mice. INS-GAS mice were infected with Helicobacter felis for 3, 6 and 9 months. At post mortem, blood was taken for assessment of iron status and gastric mucosa for pathology, immunohistology and analysis of gene expression. Chronic Helicobacter infection of INS- GAS mice resulted in decreased serum iron, transferrin saturation and hypoferritinemia and increased Total iron binding capacity (TIBC). Decreased serum iron concentrations were associated with a concomitant reduction in the number of parietal cells, strengthening the association between hypochlorhydria and gastric Helicobacter-induced iron deficiency. Infection with H. felis for nine months was associated with decreased gastric expression of iron metabolism regulators hepcidin, Bmp4 and Bmp6 but increased expression of Ferroportin 1, the iron efflux protein, iron absorption genes such as Divalent metal transporter 1, Transferrin receptor 1 and also Lcn2 a siderophore-binding protein. The INS-GAS mouse is therefore a useful model for studying Helicobacter-induced iron deficiency. Furthermore, the marked changes in expression of gastric iron transporters following Helicobacter infection may be relevant to the more rapid development of carcinogenesis in the Helicobacter infected INS-GAS model.

  8. Sulphur-binding in recent environments. II. Speciation of sulphur and iron and implications for the occurrence of organo-sulphur compounds

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hartgers, W.A.; Lopez, J.F.; Reiss, C.; Maxwell, J.R.; Grimalt, J.O.

    1997-01-01

    Speciation of iron and sulfur species was determined for two recent sediments (La Trinitat and Lake Cisó) which were deposited in environments with a high biological productivity and sulfate-reducing activity. In sediments from calcite ponds of La Trinitat an excess of reactive iron species (iron mo

  9. Dual function of novel pollen coat (surface proteins: IgE-binding capacity and proteolytic activity disrupting the airway epithelial barrier.

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    Mohamed Elfatih H Bashir

    Full Text Available BACKGROUND: The pollen coat is the first structure of the pollen to encounter the mucosal immune system upon inhalation. Prior characterizations of pollen allergens have focused on water-soluble, cytoplasmic proteins, but have overlooked much of the extracellular pollen coat. Due to washing with organic solvents when prepared, these pollen coat proteins are typically absent from commercial standardized allergenic extracts (i.e., "de-fatted", and, as a result, their involvement in allergy has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: Using a unique approach to search for pollen allergenic proteins residing in the pollen coat, we employed transmission electron microscopy (TEM to assess the impact of organic solvents on the structural integrity of the pollen coat. TEM results indicated that de-fatting of Cynodon dactylon (Bermuda grass pollen (BGP by use of organic solvents altered the structural integrity of the pollen coat. The novel IgE-binding proteins of the BGP coat include a cysteine protease (CP and endoxylanase (EXY. The full-length cDNA that encodes the novel IgE-reactive CP was cloned from floral RNA. The EXY and CP were purified to homogeneity and tested for IgE reactivity. The CP from the BGP coat increased the permeability of human airway epithelial cells, caused a clear concentration-dependent detachment of cells, and damaged their barrier integrity. CONCLUSIONS/SIGNIFICANCE: Using an immunoproteomics approach, novel allergenic proteins of the BGP coat were identified. These proteins represent a class of novel dual-function proteins residing on the coat of the pollen grain that have IgE-binding capacity and proteolytic activity, which disrupts the integrity of the airway epithelial barrier. The identification of pollen coat allergens might explain the IgE-negative response to available skin-prick-testing proteins in patients who have positive symptoms. Further study of the role of these pollen coat proteins in allergic

  10. The assessment of frequency of iron deficiency in athletes from the transferrin receptor-ferritin index.

    Science.gov (United States)

    Malczewska, J; Szczepańska, B; Stupnicki, R; Sendecki, W

    2001-03-01

    The transferrin receptor-ferritin index (sTfR/logFerr) was determined in 131 male and 121 female athletes in order to assess the frequency of iron deficiency (threshold value of that index taken as 1.8). Blood was drawn for determining morphological indices as well as sTfR, ferritin, iron, total iron binding capacity (TIBC), and haptoglobin. A significantly (p iron deficiency was observed in women (26%) than in men (11%). The iron deficiency was latent, since no subject was found to be anemic. The plasma iron was significantly lower and TIBC higher (p iron-deficient subgroups than in the non-deficient ones. This confirmed the latent character of iron deficiency. Some hematological indices (Hb, MCH, MCHC, MCV) were significantly lower in iron-deficient female athletes than in male athletes, which suggested a more profound iron deficiency in the former. The sTfR/logFerr index might thus be useful in detecting iron deficiency in athletes, especially in those with erythropoiesis disorders, since physical loads may affect the widely used ferritin levels.

  11. Iron Status in Children With Autism Spectrum Disorder

    Science.gov (United States)

    Krebs, Nancy F.; Stewart, Patricia A.; Austin, Harriet; Johnson, Susan L.; Withrow, Nikki; Molloy, Cynthia; James, S. Jill; Johnson, Cynthia; Clemons, Traci; Schmidt, Brianne; Hyman, Susan L.

    2012-01-01

    BACKGROUND AND OBJECTIVES Children with autism spectrum disorders (ASDs) often have food selectivity and restricted diets, putting them at risk for nutritional deficiencies. Previous studies have demonstrated a high prevalence of iron deficiency (ID) in children with ASDs living in Wales, Canada, and Turkey. The objectives of this study were to determine the prevalence of ID and the adequacy of iron intake in children with ASD in the United States. METHODS Participants (age 2–11 years recruited from the Autism Treatment Network Diet and Nutrition Study) completed a 3-day diet record (n = 368) and had laboratory measures of serum ferritin (SF), complete blood count, iron, total iron binding capacity, and transferrin saturation (TS) (n = 222). RESULTS Of the 222 participants with laboratory data, 18 (8%) had SF <12 µg/L and 2 (1%) had ID defined by both low SF and TS (3 children with low SF had missing TS data). One subject had iron deficiency anemia. Fewer than 2% of subjects had iron intake below the estimated average requirement. CONCLUSIONS Although the determination of iron status is complex, these data do not support previous reports that children with ASD are at greater risk for ID than the general population; however, 8% percent of the sample did demonstrate low SF despite <2% of the sample demonstrating iron intake below the estimated average requirement. The prevalence of low SF may be an underestimate, because SF is an acute phase reactant and the study included no measure of inflammation. PMID:23118246

  12. [Effect of polyphenols of coffee pulp on iron absorption].

    Science.gov (United States)

    de Rozo, M P; Vélez, J; García, L A

    1985-06-01

    The effect of the polyphenols of coffee pulp on iron absorption was studied using the method of ligated segments in rats. Optimal conditions to measure iron absorption, were determined using as criteria the concentration of Fe59 and the time that produced the highest value of blood radioactivity. A concentration of 0.4 uCi/dose of Fe59 and a 3-hr period were chosen to measure iron absorption. Experimental groups were formed assigning six rats randomly to each group. Each group was injected with a solution of 59Fe and either with the standard polyphenol solution or with the coffee pulp extract, except the control group which was injected with the Fe59 solution only. The effect of two polyphenol concentrations was also studied. Iron uptake from the duodenum was found to be the best indicator of iron absorption when compared to the sum of iron uptake by the tissues (blood, liver, spleen, kidneys, heart and carcass). Therefore, this indicator was used to interpret the results obtained. Catechin, tannic acid and the coffee pulp extract decreased significantly iron absorption when compared with the control group. The level of polyphenols used in these experiments is similar to the amounts consumed by animals fed coffee pulp at a 10% level. Therefore, we can conclude that the antinutritional effect of coffee pulp polyphenols may be partially due to their capacity to bind iron.

  13. Interaction of p-benzoquinone with hemoglobin in smoker’s blood causes alteration of structure and loss of oxygen binding capacity

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    Arunava Ghosh

    2016-01-01

    Full Text Available Cigarette smoke (CS is an important source of morbidity and early mortality worldwide. Besides causing various life-threatening diseases, CS is also known to cause hypoxia. Chronic hypoxia would induce early aging and premature death. Continuation of smoking during pregnancy is a known risk for the unborn child. Although carbon monoxide (CO is considered to be a cause of hypoxia, the effect of other component(s of CS on hypoxia is not known. Here we show by immunoblots and mass spectra analyses that in smoker’s blood p-benzoquinone (p-BQ derived from CS forms covalent adducts with cysteine 93 residues in both the β chains of hemoglobin (Hb producing Hb-p-BQ adducts. UV–vis spectra and CD spectra analyses show that upon complexation with p-BQ the structure of Hb is altered. Compared to nonsmoker’s Hb, the content of α-helix decreased significantly in smoker’s Hb (p = 0.0224. p-BQ also induces aggregation of smoker’s Hb as demonstrated by SDS-PAGE, dynamic light scattering and atomic force microscopy. Alteration of Hb structure in smoker’s blood is accompanied by reduced oxygen binding capacity. Our results provide the first proof that p-BQ is a cause of hypoxia in smokers. We also show that although both p-BQ and CO are responsible for causing hypoxia in smokers, exposure to CO further affects the function over and above that produced by Hb-p-BQ adduct.

  14. Ocean iron cycle

    Science.gov (United States)

    Boyd, Philip W.

    Interest in the biogeochemical cycle of iron has grown rapidly over the last two decades, due to the potential role of this element in modulating global climate in the geological past and ocean productivity in the present day. This trace metal has a disproportionately large effect (1 × 105 C:Fe) on photosynthetic carbon fixation by phytoplankton. In around one third of the open ocean, so-called high-nitrate low-chlorophyll (HNLC) regions, the resident phytoplankton have low growth rates despite an abundance of plant nutrients. This is due to the low supply of iron. Iron is present in the ocean in three phases, dissolved, colloidal, and particulate (biogenic and lithogenic). However, iron chemistry is complex with interactions between chemistry and biology such as the production of iron-binding siderophores by oceanic bacteria. This results in the interplay of inorganic chemistry, photochemistry, and organic complexation. Sources of new iron include dust deposition, upwelling of iron-rich deep waters, and the resuspension and lateral transport of sediments. Sinks for iron are mainly biological as evidenced by the vertical nutrient-like profile for dissolved iron in the ocean. Iron is rapidly recycled by the upper ocean biota within a so-called "ferrous wheel." The fe ratio [(new iron)/(new + regenerated iron)] provides an index of the relative supply of iron to the biota by new versus recycled iron. Over the last 15 years, interest in the potential role of iron in shaping climate in the geological past resulted in some of the most ambitious experiments in oceanography: large-scale (i.e., 50-1000 km2) iron enrichment of HNLC waters. They have provided valuable insights into how iron supply influences the biogeochemical cycles of elements such as carbon, sulfur, silicon, nitrogen, and phosphate.

  15. Study on Relativity Between Cinnamomum camphora Etiolating and Iron Binding Protein Gene%香樟黄化与铁结合蛋白基因相关性研究进展

    Institute of Scientific and Technical Information of China (English)

    张昱; 韩浩章

    2015-01-01

    Cinnamomum camphora grown in saline of the rhizosphere soil,are prone to iron-deficiency chlorosis. The research progress on relationship between Cinnamomum camphora etiolating and iron-binding protein gene was explained from three aspects,such as the relativity between Cinnamomum camphora etiolation and iron,plant ferritin gene,iron binding protein gene in plant,Cinnamomum camphora gene engineering research,in order to provide references for Cinnamomum camphora germplasm innovation by genetic engineering.%香樟在盐碱性根际土中栽培易发生缺铁性黄化病,从香樟黄化与铁元素的关系、植物体内的铁结合蛋白基因、香樟基因工程研究3个方面阐述了香樟黄化与其体内铁结合蛋白基因之间的相关性研究进展,以期为利用基因工程进行香樟种质创新提供参考。

  16. Assessment of the role of α-lipoic acid against the oxidative stress of induced iron overload

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    Yasser F. Ali

    2015-01-01

    Full Text Available This work was aimed to study the protective role of α-lipoic acid against the oxidative damage of induced iron overload. Iron (Fe overload is a complication of the treatment, by chronic transfusion, of a number of genetic diseases associated with inadequate red cell production (anemias and of other genetic diseases that lead to excessive iron absorption from the diet. Male rats were injected ip with 5 mg/kg body weight ferrous sulfate for 50 days. The animals were injected ip with α-lipoic acid 20 mg per kg body weight for 21 days. Serum iron, Total Iron Binding Capacity (TIBC, Malonyldialdehyde (MDA, Electron paramagnetic resonance (EPR spectroscopy, UV-visible absorption spectrum of hemoglobin and osmotic fragility were studied. Results showed significant increase in serum iron, total iron binding capacity, and malonyldialdehyde levels in iron-loaded rats. Treatment with lipoic acid (LA resulted in decreasing serum iron and TIBC levels by 47%and 29% respectively. At the same time the lipoic acid decreased the level of the MDA in liver, brain and plasma by 54%, 42% and 74% respectively. Also LA diminished the effect of iron-induced free radicals on erythrocyte membrane integrity; it decreased the elevated average osmotic fragility and decreased the elevated rate of hemolysis. Results from UV-visible spectrophotometric measurement of hemoglobin revealed that no oxidative changes of hemoglobin occurred in iron-loaded rats. EPR spectra showed increased in non-heme ferric ions Fe+3 and free radicals in iron-loaded rats. Whereas the injection of the lipoic acid leads to decreased in such toxic result. In conclusion, these observations suggested that lipoic acid might be a beneficial antioxidant that can be effective for limiting damage from oxidative stress of iron overload.

  17. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao, E-mail: ymwei@nwu.edu.cn

    2015-07-30

    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g{sup −1} for catechol and 736.8 μmol g{sup −1} for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6–101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples. - Highlights: • Boronate adsorbent is prepared via ATRP and chain-end functionalization. • The adsorbent has quite high binding capacity for cis-diols. • Binding capacity is easily manipulated by ATRP condition. • Chain-end functionalization can improve binding capacity significantly. • Reduced adsorbent is consumed in dispersed solid-phase extraction of cis-diols.

  18. Diagnostic Value of the Cobalt ({sup 58}Co) Excretion Test in Iron Deficiency Anemia

    Energy Technology Data Exchange (ETDEWEB)

    Sihn, Hyun Chung; Hong, Kee Suck; Cho, Kyung Sam; Song, In Kyung; Koh, Chang Soon; Lee, Mun Ho [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1976-03-15

    The diagnosis of iron deficiency rests upon the correct evaluation of body iron stores. Morphological interpretation of blood film and the red cell indices are not reliable and often absent in mild iron deficiency. Serum iron levels and iron-binding capacity are more sensitive indices of iron deficiency, but they are often normal in iron depletion and mild iron deficiency anemia. They are also subject ro many variables which may introduce substantial errors and influenced by many pathologic and physiologic states. Examination of the bone marrow aspirate for stainable iron has been regarded as one of the most sensitive and reliable diagnostic method for detecting iron deficiency, but this also has limitations. Thus, there is still need for a more practical, but sensitive and reliable substitute as a screening test of iron deficiency. Pollack et al. (1965) observed that the intestinal absorption of cobalt was raised in iron, deficient rats and Valberg et al. (1969) found that cobalt absorption was elevated in patients with iron deficiency. A direct correlation was demonstrated between the amounts of radioiron and radiocobalt absorbed. Unlike iron, excess cobalt was excreted by the kidney, the percentage of radioactivity in the urine being directly related to the percentage absorbed from the gastro-intestinal tract. Recently a test based on the urinary excretion of an oral dose of {sup 57}Co has been proposed as a method for detecting iron deficiency. To assess the diagnostic value of urinary cobalt excretion test cobaltous chloride labelled with 1 muCi of {sup 58}Co was given by mouth and the percentage of the test dose excreted in the urine was measured by a gamma counter. The mean 24 hour urinary cobalt excretion in control subjects with normal iron stores was 6.1%(1.9-15.2%). Cobalt excretion was markedly increased in patients with iron deficiency and excreted more than 29% of the dose. In contrast, patients with anemia due to causes other than iron deficiency

  19. Effects of manganese exposure on iron metabolism in peripheral blood of exposed population

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    Yun-gang XIONG

    2012-11-01

    Full Text Available Objectives  To investigate the adverse effect of manganese exposure on the iron metabolism in peripheral blood of professionally exposed workers. Methods  The manganese in air was collected using personal air sampler, and the time weighted average (TWA concentration of exposure to manganese was then calculated. The subjects were divided into exposure group (n=85 and control group (n=80 based on the exposure doses they received. The concentrations of iron and manganese in the plasma and blood cells of the subjects were determined using flame atomic absorption detector and graphite furnace atomic absorption detector. Serum ferritin, transferrin, transferrin receptor and total iron binding capacity were determined using enzyme linked immunosorbent assay. Results  The manganese contents in both plasma and blood cells were much higher in exposure group than in control group (P 0.05. It was revealed by linear correlation analysis that no linear correlation existed between the professional exposure time and manganese and iron contents in both plasma and blood cells, serum ferrin, transferrin, transferring receptor and total iron binding capacity (P>0.05. Conclusion  The long-term exposure to high dose manganese may result in an imbalance of iron metabolism in the peripheral blood in exposed population, manifesting a decrease of plasma iron and serum transferrin receptors, and an increase of serum transferrin.

  20. Obesity modulate serum hepcidin and treatment outcome of iron deficiency anemia in children: a case control study.

    Science.gov (United States)

    Sanad, Mohammed; Osman, Mohammed; Gharib, Amal

    2011-07-19

    Recently, hepcidin expression in adipose tissue has been described and shown to be increased in patients with severe obesity. We tried to assess the effect of obesity on hepcidin serum levels and treatment outcome of iron deficiency anemia in children. This was a case control study included 70 children with iron deficiency anemia "IDA" (35 obese and 35 non-obese) and 30 healthy non-obese children with comparable age and sex(control group). Parameters of iron status (Serum iron, ferritin, transferrin, total iron binding capacity and transferrin saturation) and serum hepcidin levels were assessed initially and after 3 months of oral iron therapy for IDA. Compared to the control group, serum hepcidin was significantly lower in non-obese children with IDA(p children with IDA (p children with IDA after 3 months of iron therapy (P children showed non-significant change in hepcidin level after iron therapy (p > 0.05). Although hepcidin showed significant positive correlations with Hb, serum iron and transferrin saturation in non-obese children with IDA, it showed significant negative correlations with Hb, serum iron and transferrin saturation in obese children with IDA (P iron therapy in childhood iron deficiency anemia.

  1. Arterial oxygen content is precisely maintained by graded erythrocytotic responses in settings of high/normal serum iron levels, and predicts exercise capacity: an observational study of hypoxaemic patients with pulmonary arteriovenous malformations.

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    Vatshalan Santhirapala

    Full Text Available BACKGROUND: Oxygen, haemoglobin and cardiac output are integrated components of oxygen transport: each gram of haemoglobin transports 1.34 mls of oxygen in the blood. Low arterial partial pressure of oxygen (PaO2, and haemoglobin saturation (SaO2, are the indices used in clinical assessments, and usually result from low inspired oxygen concentrations, or alveolar/airways disease. Our objective was to examine low blood oxygen/haemoglobin relationships in chronically compensated states without concurrent hypoxic pulmonary vasoreactivity. METHODOLOGY: 165 consecutive unselected patients with pulmonary arteriovenous malformations were studied, in 98 cases, pre/post embolisation treatment. 159 (96% had hereditary haemorrhagic telangiectasia. Arterial oxygen content was calculated by SaO2 x haemoglobin x 1.34/100. PRINCIPAL FINDINGS: There was wide variation in SaO2 on air (78.5-99, median 95% but due to secondary erythrocytosis and resultant polycythaemia, SaO2 explained only 0.1% of the variance in arterial oxygen content per unit blood volume. Secondary erythrocytosis was achievable with low iron stores, but only if serum iron was high-normal: Low serum iron levels were associated with reduced haemoglobin per erythrocyte, and overall arterial oxygen content was lower in iron deficient patients (median 16.0 [IQR 14.9, 17.4]mls/dL compared to 18.8 [IQR 17.4, 20.1]mls/dL, p<0.0001. Exercise tolerance appeared unrelated to SaO2 but was significantly worse in patients with lower oxygen content (p<0.0001. A pre-defined athletic group had higher Hb:SaO2 and serum iron:ferritin ratios than non-athletes with normal exercise capacity. PAVM embolisation increased SaO2, but arterial oxygen content was precisely restored by a subsequent fall in haemoglobin: 86 (87.8% patients reported no change in exercise tolerance at post-embolisation follow-up. SIGNIFICANCE: Haemoglobin and oxygen measurements in isolation do not indicate the more physiologically relevant

  2. The Porphyromonas gingivalis HmuY haemophore binds gallium(iii), zinc(ii), cobalt(iii), manganese(iii), nickel(ii), and copper(ii) protoporphyrin IX but in a manner different to iron(iii) protoporphyrin IX.

    Science.gov (United States)

    Wójtowicz, Halina; Bielecki, Marcin; Wojaczyński, Jacek; Olczak, Mariusz; Smalley, John W; Olczak, Teresa

    2013-04-01

    Porphyromonas gingivalis, a major etiological agent of chronic periodontitis, acquires haem from host haemoproteins through a haem transporter HmuR and a haemophore HmuY. The aim of this study was to analyse the binding specificity of HmuY towards non-iron metalloporphyrins which may be employed as antimicrobials to treat periodontitis. HmuY binds gallium(iii), zinc(ii), cobalt(iii), manganese(iii), nickel(ii), and copper(ii) protoporphyrin IX but in a manner different to iron(iii) protoporphyrin IX which uses His(134) and His(166) as axial ligands. The metal ions in Ga(iii)PPIX and Zn(ii)PPIX can accept only His(166) as an axial ligand, whereas nickel(ii) and copper(ii) interact exclusively with His(134). Two forms of pentacoordinate manganese(iii) are present in the Mn(iii)PPIX-HmuY complex since the metal accepts either His(134) or His(166) as a single axial ligand. The cobalt ion is hexacoordinate in the Co(iii)PPIX-HmuY complex and binds His(134) and His(166) as axial ligands; however, some differences in their environments exist. Despite different coordination modes of the central metal ion, gallium(iii), zinc(ii), cobalt(iii), and manganese(iii) protoporphyrin IX bound to the HmuY haemophore cannot be displaced by excess haem. All of the metalloporphyrins examined bind to a P. gingivalis wild-type strain with higher ability compared to a mutant strain lacking a functional hmuY gene, thus corroborating binding of non-iron metalloporphyrins to purified HmuY protein. Our results further clarify the basis of metalloporphyrin acquisition by P. gingivalis and add to understanding of the interactions with porphyrin derivatives which exhibit antimicrobial activity against P. gingivalis.

  3. Glucocorticoid treatment skews human monocyte differentiation into a hemoglobin-clearance phenotype with enhanced heme-iron recycling and antioxidant capacity.

    Science.gov (United States)

    Vallelian, Florence; Schaer, Christian A; Kaempfer, Theresa; Gehrig, Peter; Duerst, Elena; Schoedon, Gabriele; Schaer, Dominik J

    2010-12-09

    Glucocorticoids are used extensively to treat autoimmune hemolytic anemias. Some beneficial effects of glucocorticoid pulse therapy have also been reported in sickle cell disease and paroxysmal nocturnal hemoglobinuria. Based on established concepts of hemoglobin (Hb) toxicity and physiologic Hb scavenger systems, we evaluated whether glucocorticoids could support an adaptive response to extracellular Hb independently of their immunosuppressive activities. Using global proteome and transcriptome analysis with mass-spectrometry (isobaric tag for relative and absolute quantitation and liquid chromatography-mass spectrometry) and gene-array experiments, we found that glucocorticoid treatment in vitro and in patients on glucocorticoid-pulse therapy polarized monocytes into a M2/alternatively activated phenotype with high Hb-scavenger receptor (CD163) expression and enhanced Hb-clearance and detoxification capability. Monocytes concurrently exposed to the interactive activity of glucocorticoids and extracellular Hb were characterized by high expression of a group of antioxidant enzymes known to be regulated by the conserved oxidative response transcription factor nuclear factor E2-related factor. Further, suppressed transferrin receptor, together with high ferroportin expression, pointed to a shift in iron homeostasis directed toward an increased cellular export of heme-derived iron. Therefore, stimulating Hb-endocytosis by CD163 and enhancing antioxidative homeostasis and iron recycling may be an essential activity of glucocorticoids that helps alleviate the adverse effects of extracellular Hb.

  4. Effects of Iron on Hydrogen-producing Capacity,Hydrogenase and NADH-fd Reductase Activities of a Fermentative Hydrogen-producing Bacterial Strain B49

    Institute of Scientific and Technical Information of China (English)

    Wang Xiangjing(王相晶); Ren Nanqi; Xiang Wensheng

    2004-01-01

    Iron plays an important role in hydrogen production, cell growth, hydrogenase and NADH-fd reductase activities of hydrogen-producing bacterial strain B49 (AF481148 in EMBL). At the end of fermentation from 10 g/L glucose, for the culture containing 10 mg/L FeSO4*7H2O the cell growth in terms of optical density (OD) at 600nm was 1.13, the ratio of ethanol amount (mg/L) to acetate amount (mg/L) was 1.55, and the accumulated hydrogen volume was 1816.3 ml H2/L culture; whereas for the culture of 80 mg/L FeSO4*7H2O OD600nm was increased to 1.34, the accumulated hydrogen volume was increased to 2360.5 ml H2/L culture, and the ratio of ethanol amount (mg/L) to acetate amount (mg/L) decreased to 1.31. Moreover, the iron addition to the medium at different fermentation time could affect hydrogen-producing ability. However, the later the addition time of FeSO4*7H2O was postponed, the less the effect on hydrogen evolution was. In the course of fermentation, the specific activities of hydrogenase and NADH-fd reductase of hydrogen-producing bacterial strain B49 decreased with the consumption of iron.

  5. Iron deficiency in chronic systolic heart failure(indic study

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    Sunil Verma

    2016-01-01

    Full Text Available Background: Chronic systolic heart failure (HF is characterized by the left ventricular dysfunction, exercise intolerance and is associated with neurohormonal activation that affects several organs such as kidney and skeletal muscle. Anemia is common in HF and may worsen symptoms. Iron deficiency (ID is also common in HF patients with or without anemia. Iron is the key cofactor in oxidative metabolism in skeletal muscle and the Krebs cycle. There is a paucity of data regarding iron metabolism in chronic systolic HF in India. Methods: IroN Deficiency In CHF study (INDIC is an observational study that investigated forty chronic heart failure patients for the presence of ID. Serum ferritin (micrograms per liter, serum iron (micrograms per liter, total iron binding capacity (micrograms per liter, transferring (milligrams per deciliter, and transferrin saturation were measured to assess iron status. Results: There were 67.5% (27/40 patients who had ID with a mean serum ferritin level of 76.4 μg/L. Of the 27 iron deficient patients, 22 (55% had an absolute ID, and 5 had a functional ID. Eight out of 27 of the iron deficient patients were anemic (20% of the total cohort, 30% of the iron deficient patients. Anemia was seen in 6 other patients, which was possibly anemia of chronic disease. There was a trend for more advanced New York Heart Association (NYHA class (NYHA III and NYHA IV patients with ID (37.4% vs. 30.77%, P = 0.697. Conclusion: In our study, ID was very common, affecting more than half of the patients with systolic HF. Absolute ID was the most common cause of ID and patients with ID had a tendency to have advanced NYHA class. Our study also demonstrated that ID can occur in the absence of anemia (iron depletion.

  6. Label-Free LC-MS Profiling of Skeletal Muscle Reveals Heart-Type Fatty Acid Binding Protein as a Candidate Biomarker of Aerobic Capacity

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    Zulezwan A. Malik

    2013-12-01

    Full Text Available Two-dimensional gel electrophoresis provides robust comparative analysis of skeletal muscle, but this technique is laborious and limited by its inability to resolve all proteins. In contrast, orthogonal separation by SDS-PAGE and reverse-phase liquid chromatography (RPLC coupled to mass spectrometry (MS affords deep mining of the muscle proteome, but differential analysis between samples is challenging due to the greater level of fractionation and the complexities of quantifying proteins based on the abundances of their tryptic peptides. Here we report simple, semi-automated and time efficient (i.e., 3 h per sample proteome profiling of skeletal muscle by 1-dimensional RPLC electrospray ionisation tandem MS. Solei were analysed from rats (n = 5, in each group bred as either high- or low-capacity runners (HCR and LCR, respectively that exhibited a 6.4-fold difference (1,625 ± 112 m vs. 252 ± 43 m, p < 0.0001 in running capacity during a standardized treadmill test. Soluble muscle proteins were extracted, digested with trypsin and individual biological replicates (50 ng of tryptic peptides subjected to LC-MS profiling. Proteins were identified by triplicate LC-MS/MS analysis of a pooled sample of each biological replicate. Differential expression profiling was performed on relative abundances (RA of parent ions, which spanned three orders of magnitude. In total, 207 proteins were analysed, which encompassed almost all enzymes of the major metabolic pathways in skeletal muscle. The most abundant protein detected was type I myosin heavy chain (RA = 5,843 ± 897 and the least abundant protein detected was heat shock 70 kDa protein (RA = 2 ± 0.5. Sixteen proteins were significantly (p < 0.05 more abundant in HCR muscle and hierarchal clustering of the profiling data highlighted two protein subgroups, which encompassed proteins associated with either the respiratory chain or fatty acid oxidation. Heart-type fatty acid binding protein (FABPH was 1

  7. Relationship between indices of iron status and metabolic syndrome in an Iranian population

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    Niloofar Tavakoli-Hoseini

    2014-11-01

    Full Text Available Introduction: Iron overload may contribute to the pathogenesis of metabolic syndrome (MS. A growing body of evidence indicates that the oxidative stress that results from excess tissue iron can leads to insulin resistance, tissue damage, and other complications observed in MS. The objective of this study was to investigate indices of iron status including serum ferritin, iron, total iron binding capacity (TIBC levels, and full blood cell count, together with demographic and anthropometric characteristics, lipid profile components, and other biochemical parameters in subjects with and with-out MS. Methods: A total of, 385 individuals (176 with and 209 subjects without MS according to the International Diabetes Federation’s (IDF criteria were recruited. Indices of iron status and other clinical and biochemical parameters were determined in MS patients and healthy controls using standard methods. Results: Higher serum iron and ferritin values were observed in subjects with MS in compared to healthy controls (P 0.050. Among the other indices, only red blood cell (RBC was associated considerably with the presence of MS (P < 0.050. Conclusion: Our data indicate that even in a country with a comparatively high prevalence of iron deficiency, serum iron and ferritin values in MS patients are higher than healthy controls. The reason why ferritin and iron are higher in MS patient may be related to dietary factors.

  8. Prevalence of Iron deficiency anemia in children with liver cirrhosis: A cross-sectional study

    Science.gov (United States)

    Zareifar, Soheila; Dehghani, Seyed Mohsen; Rahanjam, Najmeh; Farahmand Far, Mohammad Reza

    2015-01-01

    Background: Among the many complications reported for cirrhosis, iron deficiency anemia (IDA) has attracted much attention. This type of anemia, in contrast to other types of anemia, is easy to treat prophylactically, but if left untreated can lead to a poor quality of life. The aim of this study was to estimate the hemoglobin and serum iron levels among patients with liver cirrhosis for the early diagnosis of IDA and to avoid unnecessary testing and iron supplementation. Subjects and Methods: In this cross-sectional study, 88 children diagnosed with cirrhosis were included, and the values of hemoglobin, serum iron levels and relationship between serum iron (SI), total iron-binding capacity (TIBC), prothrombine time (PT), international normalization ratio (INR), total and direct bilirubin and hepatic enzymes were estimated using paired t test, Mann-Whitney, Chi-square and Kruskal-Wallis tests. Results: Forty-six (52.3%) of 88 children were girls and 42 (47.7%) were boys. Forty-eight (54.5%) patients had anemia and 8 (9%) had iron deficiency anemia (5 boys, 5.6%, and 3 girls, 3.4%). No relationships were observed between iron deficiency anemia and the patient’s age or gender, whereas there was a relationship between iron deficiency and severity and duration of the disease, although the correlation was not statistically significant. Conclusion: The high frequency of iron deficiency anemia in children with cirrhosis (9%) suggests that timely screening should be used for early diagnosis and treatment. PMID:26261697

  9. Correction of anemia and iron deficiency in vegetarians by administration of ascorbic acid.

    Science.gov (United States)

    Sharma, D C; Mathur, R

    1995-10-01

    Twenty-eight strict vegetarians were given 500 mg ascorbic acid twice daily after lunch and dinner for two months. Hemoglobin and certain iron status parameters were measured before and after the treatment. Ascorbate treatment increased mean hemoglobin by 8%, serum iron by 17% and transferrin saturation by 23% and decreased total iron binding capacity by 7%. All these changes were statistically significant. The rise in serum ferritin was 12%. The serum protein or copper level did not indicate their dietary deficiency, while initial serum ascorbate level were low which rose by 60% on therapy. It is concluded that ascorbate supplementation is a better method of improving hematologic and iron status than iron salt administration.

  10. The impact of iron deficiency and anaemia on exercise capacity and outcomes in patients with chronic heart failure. Results from the Studies Investigating Co-morbidities Aggravating Heart Failure.

    Science.gov (United States)

    Ebner, Nicole; Jankowska, Ewa A; Ponikowski, Piotr; Lainscak, Mitja; Elsner, Sebastian; Sliziuk, Veronika; Steinbeck, Lisa; Kube, Jennifer; Bekfani, Tarek; Scherbakov, Nadja; Valentova, Miroslava; Sandek, Anja; Doehner, Wolfram; Springer, Jochen; Anker, Stefan D; von Haehling, Stephan

    2016-02-15

    Anaemia and iron deficiency (ID) are important co-morbidities in patients with chronic heart failure (HF) and both may lead to reduced exercise capacity. We enrolled 331 out-patients with stable chronic HF (mean age: 64 ± 11 years, 17% female, left ventricular ejection fraction [LVEF] 35 ± 13%, body mass index [BMI] 28.5 ± 5.2 kg/m(2), New York Heart Association [NYHA] class 2.2 ± 0.7, chronic kidney disease 35%, glomerular filtration rate 61.7 ± 20.1 mL/min). Anaemia was defined according to World Health Organization criteria (haemoglobin [Hb] < 13 g/dL in men, < 12 g/dL in women). ID was defined as serum ferritin < 100 μg/L or ferritin < 300 μg/L with transferrin saturation (TSAT) < 20%. Exercise capacity was assessed as peak oxygen consumption (peak VO2) by spiroergometry and 6-minute walk test (6MWT). A total of 91 (27%) patients died from any cause during a mean follow-up of 18 months. At baseline, 98 (30%) patients presented with anaemia and 149 (45%) patients presented with ID. We observed a significant reduction in exercise capacity in parallel to decreasing Hb levels (r = 0.24, p < 0.001). In patients with anaemia and ID (n = 63, 19%), exercise capacity was significantly lower than in patients with ID or anaemia only. Cox regression analysis showed that after adjusting for NYHA, age, hsCRP and creatinine anaemia is an independent predictor of mortality in patients with HF (hazard ratio [HR]: 0.56, 95% confidence interval [CI]: 0.33-0.97, p = 0.04). The impact of anaemia on reduced exercise capacity and on mortality is stronger than that of ID. Anaemia remained an independent predictor of death after adjusting for clinically relevant variables. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. A novel mode of ferric ion coordination by the periplasmic ferric ion-binding subunit FbpA of an ABC-type iron transporter from Thermus thermophilus HB8.

    Science.gov (United States)

    Wang, Shipeng; Ogata, Misaki; Horita, Shoichiro; Ohtsuka, Jun; Nagata, Koji; Tanokura, Masaru

    2014-01-01

    Crystal structures of FbpA, the periplasmic ferric ion-binding protein of an iron-uptake ABC transporter, from Thermus thermophilus HB8 (TtFbpA) have been solved in apo and ferric ion-bound forms at 1.8 and 1.7 Å resolution, respectively. The latter crystal structure shows that the bound ferric ion forms a novel six-coordinated complex with three tyrosine side chains, two bicarbonates and a water molecule in the metal-binding site. The results of gel-filtration chromatography and dynamic light scattering show that TtFbpA exists as a monomer in solution regardless of ferric ion binding and that TtFbpA adopts a more compact conformation in the ferric ion-bound state than in the apo state in solution.

  12. Solid waste removes toxic liquid waste: adsorption of chromium(VI) by iron complexed protein waste.

    Science.gov (United States)

    Fathima, Nishtar Nishad; Aravindhan, Rathinam; Rao, Jonnalagadda Raghava; Nair, Balachandran Unni

    2005-04-15

    The leather processing industry generates huge amounts of wastes, both in solid and liquid form. Fleshing from animal hides/skins is one such waste that is high in protein content. In this study, raw fleshing has been complexed with iron and is used for removal of chromium(VI). The effect of pH and the initial concentration of chromium(VI) on the removal of Cr(IV) by iron treated fleshing is presented. Iron treatment is shown to greatly improve adsorption of the fleshing for hexavalent chromium. The ultimate adsorption capacity of iron treated fleshing is 51 mg of chromium(VI) per gram of fleshing. That of untreated fleshing is 9 mg/g such that iron treatment increases the adsorption capacity of fleshing by 10-fold. The measured adsorption kinetics is well described by a pseudo-second-order kinetic model. The uptake of chromium(VI) by fleshing is best described by the Langmuir adsorption isotherm model. X-ray photoelectron spectroscopic (XPS) studies show that the iron is incorporated into the protein matrix. Shifts in XPS spectra suggest that dichromate binding occurs with iron at active adsorption sites and that iron treated fleshing removes chromium(VI) without reducing it to chromium(III).

  13. Iron uptake in ferritin is blocked by binding of [Cr(TREN)(H(2)O)(OH)](2+), a slow dissociating model for [Fe(H(2)O)(6)](2+).

    Science.gov (United States)

    Barnés, Carmen M; Theil, Elizabeth C; Raymond, Kenneth N

    2002-04-16

    Ferritin concentrates iron as a hydrous ferric oxide in a protein cavity (8 nm in diameter) by using eight pores along the threefold symmetry axes of the octahedral supramolecular structure. The role of ligand exchange in the entry of Fe(II) hexahydrate into ferritin protein has been studied with [Cr(TREN)(H(2)O)(OH)](2+) [TREN = N(CH(2)CH(2)NH(2))(3)], a model for Fe(H(2)O)(6)2+ with only two exchangeable ligands. The results show that five different ferritin proteins, varying in pore structure, oxidation sites, and nucleation sites, bind Cr(TREN) at functional protein sites, based on inhibition of iron mineralization and oxidation. Properties of Cr(TREN)-ferritin adducts include an increased isoelectric point, a shift in the Cr(TREN) UV/vis spectrum consistent with exchange of water for protein carboxylate or thiolate ligands, binding affinities of 50-250 microM, and a slow rate of dissociation (k = 4 x 10(-6) sec(-1)). The relationship of Cr(TREN) inhibition of iron oxidation and mineralization by Cr(TREN) to the known structures of the various ferritins tested suggests that Cr(TREN) plugs the ferritin pores, obstructing Fe(II) entry in folded and unfolded pores. Because only two exchangeable waters are sufficient for pore binding of Cr(TREN), the physiological Fe(II) donor must bind to the pore with few exchangeable ligands. These results show the advantage of using stable model complexes to explore properties of transient Fe-protein complexes during Fe mineralization in ferritin.

  14. Serum Hepcidin Levels, Iron Dyshomeostasis and Cognitive Loss in Alzheimer’s Disease

    Science.gov (United States)

    Sternberg, Zohara; Hu, Zihua; Sternberg, Daniel; Waseh, Shayan; Quinn, Joseph F.; Wild, Katharine; Jeffrey, Kaye; Zhao, Lin; Garrick, Michael

    2017-01-01

    This pilot study examined the status of the master iron regulatory peptide, hepcidin, and peripheral related iron parameters in Alzheimer’s disease (AD) and mild cognitive impairment patients, and evaluated the relationship between iron dyshomeostasis and amyloid-beta (Aβ), cognitive assessment tests, neuroimaging and clinical data. Frozen serum samples from the Oregon Tissue Bank were used to measure serum levels of hepcidin, ferritin, Aβ40, Aβ42 using enzyme-linked immunosorbent assay. Serum transferrin levels were determined indirectly as total iron binding capacity, serum iron was measured and the percent saturation of transferrin calculated. The study variables were correlated with the patients’ existing cognitive assessment tests, neuroimaging, and clinical data. Hepcidin, and iron-related proteins tended to be higher in AD patients than controls, reaching statistical significance for ferritin, whereas Aβ40, Aβ42 serum levels tended to be lower. Patients with pure AD had three times higher serum hepcidin levels than controls; gender differences in hepcidin and iron-related proteins were observed. Patient stratification based on clinical dementia rating-sum of boxes revealed significantly higher levels of iron and iron-related proteins in AD patients in the upper 50% as compared to controls, suggesting that iron dyshomeostasis worsens as cognitive impairment increases. Unlike Aβ peptides, iron and iron-related proteins showed significant association with cognitive assessment tests, neuroimaging, and clinical data. Hepcidin and iron-related proteins comprise a group of serum biomarkers that relate to AD diagnosis and AD disease progression. Future studies should determine whether strategies targeted to diminishing hepcidin synthesis/secretion and improving iron homeostasis could have a beneficial impact on AD progression. PMID:28400987

  15. A Golgi-localized MATE transporter mediates iron homoeostasis under osmotic stress in Arabidopsis.

    Science.gov (United States)

    Seo, Pil Joon; Park, Jungmin; Park, Mi-Jeong; Kim, Youn-Sung; Kim, Sang-Gyu; Jung, Jae-Hoon; Park, Chung-Mo

    2012-03-15

    Iron is an essential micronutrient that acts as a cofactor in a wide variety of pivotal metabolic processes, such as the electron transport chain of respiration, photosynthesis and redox reactions, in plants. However, its overload exceeding the cellular capacity of iron binding and storage is potentially toxic to plant cells by causing oxidative stress and cell death. Consequently, plants have developed versatile mechanisms to maintain iron homoeostasis. Organismal iron content is tightly regulated at the steps of uptake, translocation and compartmentalization. Whereas iron uptake is fairly well understood at the cellular and organismal levels, intracellular and intercellular transport is only poorly understood. In the present study, we show that a MATE (multidrug and toxic compound extrusion) transporter, designated BCD1 (BUSH-AND-CHLOROTIC-DWARF 1), contributes to iron homoeostasis during stress responses and senescence in Arabidopsis. The BCD1 gene is induced by excessive iron, but repressed by iron deficiency. It is also induced by cellular and tissue damage occurring under osmotic stress. The activation-tagged mutant bcd1-1D exhibits leaf chlorosis, a typical symptom of iron deficiency. The chlorotic lesion of the mutant was partially recovered by iron feeding. Whereas the bcd1-1D mutant accumulated a lower amount of iron, the iron level was elevated in the knockout mutant bcd1-1. The BCD1 protein is localized to the Golgi complex. We propose that the BCD1 transporter plays a role in sustaining iron homoeostasis by reallocating excess iron released from stress-induced cellular damage.

  16. Exercise-induced changes in iron status and hepcidin response in female runners.

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    Irena Auersperger

    Full Text Available BACKGROUND AND AIMS: Exercise-induced iron deficiency is a common finding in endurance athletes. It has been suggested recently that hepcidin may be an important mediator in this process. OBJECTIVE: To determine hepcidin levels and markers of iron status during long-term exercise training in female runners with depleted and normal iron stores. METHODS: Fourteen runners were divided into two groups according to iron status. Blood samples were taken during a period of eight weeks at baseline, after training and after ten days' recovery phase. RESULTS: Of 14 runners, 7 were iron deficient at baseline and 10 after training. Hepcidin was lower at recovery compared with baseline (p<0.05. The mean cell haemoglobin content, haemoglobin content per reticulocyte and total iron binding capacity all decreased, whereas soluble transferrin receptor and hypochromic red cells increased after training and recovery (p<0.05 for all. CONCLUSION: The prevalence of depleted iron stores was 71% at the end of the training phase. Hepcidin and iron stores decreased during long-term running training and did not recover after ten days, regardless of baseline iron status.

  17. Disaccharidase levels in normal epithelium of the small intestine of rats with iron-deficiency anemia

    Directory of Open Access Journals (Sweden)

    M.I.M. Fernandes

    1997-07-01

    Full Text Available Iron-deficiency anemia is the nutritional deficiency most frequently occurring throughout the world, which manifests as a complex systemic disease involving all cells, affecting enzyme activities and modifying protein synthesis. In view of these considerations, the objective of the present study was to determine the effects of iron-deficiency anemia on disaccharidases and on the epithelial morphokinetics of the jejunal mucosa. Newly weaned male Wistar rats were divided into 4 groups of 10 animals each: C6w received a standard ration containing 36 mg elemental iron per kg ration for 6 weeks; E6w received an iron-poor ration (5-8 mg/kg ration for 6 weeks; C10w received an iron-rich ration (36 mg/kg ration for 10 weeks; E10w received an iron-poor ration for 6 weeks and then an iron-rich ration (36 mg/kg for an additional 4 weeks. Jejunal fragments were used to measure disaccharidase content and to study cell proliferation. The following results were obtained: 1 a significant reduction (P<0.001 of animal weight, hemoglobin (Hb, serum iron and total iron-binding capacity (TIBC in group E6w as compared to C6w; reversal of the alterations in Hb, serum iron and TIBC with iron repletion (E10w = C10w; animal weights continued to be significantly different in groups E10w and C10w. 2 Sucrase and maltase levels were unchanged; total and specific lactase levels were significantly lower in group E6w and this reduction was reversed by iron repletion (E10w = C10w. 3 The cell proliferation parameters did not differ between groups. On the basis of these results, we conclude that lactase production was influenced by iron deficiency and that this fact was not related to changes in cell population and proliferation in the intestinal mucosa

  18. Underestimation of the coexistence of iron deficiencies and thalassemia minors: a single institution experience in Taiwan.

    Science.gov (United States)

    Lin, Chung-King; Chen, Ling-Ping; Chang, Hsiu-Lin; Sung, Yung-Chuan

    2014-08-01

    Some physicians neglect the possible coexistence of an iron deficiency with a thalassemia minor and do not treat the iron deficiency accordingly. This motivated us to conduct this study. We retrospectively reviewed the records of 3892 patients who visited our clinics and had hemoglobin (Hb) electrophoreses performed in our hematologic laboratory from August 1, 2007 to December 31, 2012. The thalassemia minors were identified by characteristic complete blood count (CBC) parameters obtained from an autoanalyzer and Hb electrophoresis, and some cases were confirmed with molecular tests. Then, we checked iron studies [ferritin and/or serum iron with total iron-binding capacity (TIBC)] to determine the coexistence of an iron deficiency with a thalassemia minor and a response to iron, if such treatments were given. We found 792 cases with thalassemia minors, and excluded those without iron studies, with 661 cases as our sample. A total of 202/661 cases (31%) also had iron deficiencies. They had lower red blood cell (RBC) counts, Hb, and ferritin levels as compared to those thalassemia minor cases without coexistence of iron deficiencies. We concluded that the thalassemia minor patients did not have iron overload complications in our population. On the contrary, iron deficiencies commonly coexist in the clinical visits. We propose that if Hb thalassemia minor, one should screen for iron deficiency simultaneously. The sensitivity is 79.8% and the specificity is 82.6%. Therefore, physicians should be aware of this coexisting condition, and know how to recognize and treat it accordingly. Copyright © 2014. Published by Elsevier B.V.

  19. Iron deficiency and iron deficiency anemia in women.

    Science.gov (United States)

    Coad, Jane; Pedley, Kevin

    2014-01-01

    Iron deficiency is one of the most common nutritional problems in the world and disproportionately affects women and children. Stages of iron deficiency can be characterized as mild deficiency where iron stores become depleted, marginal deficiency where the production of many iron-dependent proteins is compromised but hemoglobin levels are normal and iron deficiency anemia where synthesis of hemoglobin is decreased and oxygen transport to the tissues is reduced. Iron deficiency anemia is usually assessed by measuring hemoglobin levels but this approach lacks both specificity and sensitivity. Failure to identify and treat earlier stages of iron deficiency is concerning given the neurocognitive implications of iron deficiency without anemia. Most of the daily iron requirement is derived from recycling of senescent erythrocytes by macrophages; only 5-10 % comes from the diet. Iron absorption is affected by inhibitors and enhancers of iron absorption and by the physiological state. Inflammatory conditions, including obesity, can result in iron being retained in the enterocytes and macrophages causing hypoferremia as a strategic defense mechanism to restrict iron availability to pathogens. Premenopausal women usually have low iron status because of iron loss in menstrual blood. Conditions which further increase iron loss, compromise absorption or increase demand, such as frequent blood donation, gastrointestinal lesions, athletic activity and pregnancy, can exceed the capacity of the gastrointestinal tract to upregulate iron absorption. Women of reproductive age are at particularly high risk of iron deficiency and its consequences however there is a controversial argument that evolutionary pressures have resulted in an iron deficient phenotype which protects against infection.

  20. Nirmali Seed as a Natural Biosorbent; Evaluation of its Potential for Iron (II Removal from Steel Plant Effluents and Sewage Disinfecting Capacity

    Directory of Open Access Journals (Sweden)

    Y. Avasn Maruthi

    2013-10-01

    Full Text Available The idea of water clarification by natural coagulants is many centuries old. Naturalcoagulants like Moring oelifera, Mangifera indica and Prunusarmeniaca,Strychnospotatorum are used for the treatment of waste waters. Nirmali Seed is a naturalcoagulant material with polyelectrolytes. These polyelectrolytes are responsible forcoagulation property of Nirmali seeds. In general, the studies rampant in the literaturereported application of Nirmali seed powder as water extract or as powder with doseselection using jar test. The treatment in most of the cases is based upon coagulation andremoval. But in this study it has been modified that the methodology to suit our objectivesas wanted to test the potential of Nirmali seed as a solid bio-sorbent surface in solidsolution equilibrium adsorption studies. The dose selection has been done keeping in mindthe amount of polyelectrolyte released when the seed powder is left in solution. Theproperty of physi-sorption aided with chemi-sorption with minimum dose has been givenimportance in the present study.The chief goal of this study is to find out the feasibility of applications of Nirmali Seedsfor both Iron (II reduction as well as disinfecting agent for sewage samples.

  1. Predicted metal binding sites for phytoremediation.

    Science.gov (United States)

    Sharma, Ashok; Roy, Sudeep; Tripathi, Kumar Parijat; Roy, Pratibha; Mishra, Manoj; Khan, Feroz; Meena, Abha

    2009-09-05

    Metal ion binding domains are found in proteins that mediate transport, buffering or detoxification of metal ions. The objective of the study is to design and analyze metal binding motifs against the genes involved in phytoremediation. This is being done on the basis of certain pre-requisite amino-acid residues known to bind metal ions/metal complexes in medicinal and aromatic plants (MAP's). Earlier work on MAP's have shown that heavy metals accumulated by aromatic and medicinal plants do not appear in the essential oil and that some of these species are able to grow in metal contaminated sites. A pattern search against the UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases yielded true positives in each case showing the high specificity of the motifs designed for the ions of nickel, lead, molybdenum, manganese, cadmium, zinc, iron, cobalt and xenobiotic compounds. Motifs were also studied against PDB structures. Results of the study suggested the presence of binding sites on the surface of protein molecules involved. PDB structures of proteins were finally predicted for the binding sites functionality in their respective phytoremediation usage. This was further validated through CASTp server to study its physico-chemical properties. Bioinformatics implications would help in designing strategy for developing transgenic plants with increased metal binding capacity. These metal binding factors can be used to restrict metal update by plants. This helps in reducing the possibility of metal movement into the food chain.

  2. Targeting Iron Deficiency Anemia in Heart Failure.

    Science.gov (United States)

    Saraon, Tajinderpal; Katz, Stuart D

    2016-01-01

    Iron deficiency is common in heart failure (HF) patients, and is associated with increased risk of adverse clinical outcomes. Clinical trials of intravenous iron supplementation in iron-deficient HF patients have demonstrated short-term improvement in functional capacity and quality of life. In some trials, the benefits of iron supplementation were independent of the hemoglobin levels. Additional investigations of iron supplementation are needed to characterize the mechanisms contributing to clinical benefit and long-term safety in HF.

  3. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules.

    Science.gov (United States)

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao

    2015-07-30

    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g(-1) for catechol and 736.8 μmol g(-1) for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6-101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples.

  4. The Histone Deacetylase Complex 1 Protein of Arabidopsis Has the Capacity to Interact with Multiple Proteins Including Histone 3-Binding Proteins and Histone 1 Variants.

    Science.gov (United States)

    Perrella, Giorgio; Carr, Craig; Asensi-Fabado, Maria A; Donald, Naomi A; Páldi, Katalin; Hannah, Matthew A; Amtmann, Anna

    2016-05-01

    Intrinsically disordered proteins can adopt multiple conformations, thereby enabling interaction with a wide variety of partners. They often serve as hubs in protein interaction networks. We have previously shown that the Histone Deacetylase Complex 1 (HDC1) protein from Arabidopsis (Arabidopsis thaliana) interacts with histone deacetylases and quantitatively determines histone acetylation levels, transcriptional activity, and several phenotypes, including abscisic acid sensitivity during germination, vegetative growth rate, and flowering time. HDC1-type proteins are ubiquitous in plants, but they contain no known structural or functional domains. Here, we explored the protein interaction spectrum of HDC1 using a quantitative bimolecular fluorescence complementation assay in tobacco (Nicotiana benthamiana) epidermal cells. In addition to binding histone deacetylases, HDC1 directly interacted with histone H3-binding proteins and corepressor-associated proteins but not with H3 or the corepressors themselves. Surprisingly, HDC1 also was able to interact with variants of the linker histone H1. Truncation of HDC1 to the ancestral core sequence narrowed the spectrum of interactions and of phenotypic outputs but maintained binding to a H3-binding protein and to H1. Thus, HDC1 provides a potential link between H1 and histone-modifying complexes.

  5. Lipopolysaccharide (LPS) processing by Kupffer cells releases a modified LPS with increased hepatocyte binding and decreased tumor necrosis factor-alpha stimulatory capacity.

    Science.gov (United States)

    Treon, S P; Thomas, P; Broitman, S A

    1993-02-01

    Normal physiological clearance of gut-derived endotoxin lipopolysaccharide [LPS] has been described previously; initially, there is uptake by Kupffer cells (KC), then release of modified LPS, followed by hepatocyte uptake. Previous work in our laboratories indicated that LPS is structurally modified with loss of carbohydrate prior to its release by KC. In this study, we functionally characterize KC modified LPS. KC-modified 125I-LPS was prepared from primary rat KC. Escherichia coli 0127:B8 native 125I-LPS or KC-modified 125I-LPS (40 ng) was incubated for 1 hr with 1 x 10E6 primary hepatocytes. The binding of KC-modified LPS was 4.33-fold higher than native LPS (P = 0.0024). Binding analysis studies were conducted to determine the region of KC-modified LPS responsible for enhanced hepatocyte binding. KC-modified Salmonella minnesota LPS was competed with 100-fold excess native or mutant (Ra, Rc, Rd, or Re) strains of LPS or Lipid A with no decrease to hepatocyte binding. S. minnesota-native 125I-LPS was compared with KC-modified 125I-LPS in a study to assess induction of tumor necrosis factor (TNF)-gamma by rat peritoneal macrophages. Native or KC-modified 125I-LPS (100 ng) was presented to 1 x 10E7 peritoneal macrophages for 6 hr. TNF-alpha was measured in supernatants using the WEHI-164 cytotoxicity assay. Native LPS induced 5.7-fold higher TNF-alpha levels than KC-modified LPS (P < 0.0001). The above data suggest that structural alterations in KC-modified LPS are accompanied by functional alterations resulting in enhanced hepatocyte binding and decreased TNF-alpha release. The latter result implies that an early step in LPS detoxification occurs in the KC in which LPS is modified to prevent elicitation of biologically active cytokines.

  6. Non-transferrin-bound iron (NTBI uptake by T lymphocytes: evidence for the selective acquisition of oligomeric ferric citrate species.

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    Joao Arezes

    Full Text Available Iron is an essential nutrient in several biological processes such as oxygen transport, DNA replication and erythropoiesis. Plasma iron normally circulates bound to transferrin. In iron overload disorders, however, iron concentrations exceed transferrin binding capacity and iron appears complexed with low molecular weight molecules, known as non-transferrin-bound iron (NTBI. NTBI is responsible for the toxicity associated with iron-overload pathologies but the mechanisms leading to NTBI uptake are not fully understood. Here we show for the first time that T lymphocytes are able to take up and accumulate NTBI in a manner that resembles that of hepatocytes. Moreover, we show that both hepatocytes and T lymphocytes take up the oligomeric Fe3Cit3 preferentially to other iron-citrate species, suggesting the existence of a selective NTBI carrier. These results provide a tool for the identification of the still elusive ferric-citrate cellular carrier and may also open a new pathway towards the design of more efficient iron chelators for the treatment of iron overload disorders.

  7. Preparation and Bioavailability Analysis of Ferrous Bis Alanine Chelate as a New Micronutrient for Treatment of Iron Deficiency Anemia.

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    Zargaran, Marzieh; Saadat, Ebrahim; Dinarvand, Rassoul; Sharifzadeh, Mohammad; Dorkoosh, Farid

    2016-09-01

    Purpose: One of the most nutritional disorders around the world is iron deficiency. A novel iron compound was synthesized by chelating ferrous ions with alanine for prevention and treatment of iron deficiency anemia. Methods: The newly synthesized compound was characterized both qualitatively and quantitatively by Fourier Transform Infrared (FT-IR) spectroscopy. The bioavailability of newly synthesized iron micronutrient was evaluated in four groups of Wistar rats. The group I was a negative control group and the other three groups received three different iron formulations. After 14 days, the blood samples were taken and analyzed accordingly. Results: Calculations showed that more than 91.8% of iron was incorporated in the chelate formulation. In vivo studies showed that serum iron, total iron binding capacity and hemoglobin concentrations were significantly increased in group IV, which received ferrous bis alanine chelate compared with the negative control group (pferrous sulfate.7H2O (pferrous bis glycine. Conclusion: The results showed better bioavailability of ferrous bis alanine as a new micronutrient for treatment of iron deficiency anemia in comparison with ferrous sulfate. Ferrous bis alanine could be considered as a suitable supplement for prevention and treatment of iron deficiency anemia.

  8. Iron status in HIV-1 infection: implications in disease pathology

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    Banjoko S Olatunbosun

    2012-12-01

    Full Text Available Abstract Background There had been conflicting reports with levels of markers of iron metabolism in HIV infection. This study was therefore aimed at investigating iron status and its possible mediation of severity of HIV- 1 infection and pathogenesis. Method Eighty (80 anti-retroviral naive HIV-1 positive and 50 sero-negative controls were recruited for the study. Concentrations of serum total iron, transferrin, total iron binding capacity (TIBC, CD4+ T -lymphocytes, vitamin C, zinc, selenium and transferrin saturation were estimated. Results The mean CD4+ T-lymphocyte cell counts, serum iron, TIBC, transferrin saturation for the tests and controls were 319 ± 22, 952 ± 57 cells/μl (P 4+ T-lymphocyte cell count had a positive correlation with levels of vitamin C (r = 0.497, P Conclusion It could be inferred that derangement in iron metabolism, in addition to oxidative stress, might have contributed to the depletion of CD4+ T cell population in our subjects and this may result in poor prognosis of the disease.

  9. A cathode material based on the iron fluoride with an ultra-thin Li3FeF6 protective layer for high-capacity Li-ion batteries

    Science.gov (United States)

    Yang, Juan; Xu, Zhanglin; Zhou, Haochen; Tang, Jingjing; Sun, Hongxu; Ding, Jing; Zhou, Xiangyang

    2017-09-01

    Iron fluoride based on the multi-electron reaction is a typical representative among the new-style cathode materials for Lithium-ion batteries, which is attracting extensive attentions. To relieve the cathode dissolution and interfacial side reactions and improve the electrochemical performance of FeF3·0.33H2O, we design an ultra-thin Li3FeF6 protective layer, which is in-situ formed on the surface of FeF3·3H2O particles by a facile process. The prepared Li3FeF6/FeF3·0.33H2O (LF50) composite displays a superior rate performance (152 mAh g-1 at 1000 mA g-1), which is remarkable to many other carbon-free iron fluorides. And it is noticeable that a reversible capacity of 174 mAh g-1 can be retained after 100 cycles, indicating an outstanding cycling stability contrast to the bare FeF3·0.33H2O. The enhanced electrochemical performance is attributed to the protection of Li3FeF6 layer which reduces the cathode dissolution and interfacial side reactions. Moreover, the agglomeration of first particles in the calcination process is effectively suppressed resulting from the introduction of the Li3FeF6 protective layer, which promotes electrolyte penetration and charge transfer in the composites. It is expected that the strategy can provide a new approach for the modification of other metal fluoride.

  10. Characterizing rapid capacity fade and impedance evolution in high rate pulsed discharged lithium iron phosphate cells for complex, high power loads

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    Wong, Derek N.; Wetz, David A.; Heinzel, John M.; Mansour, Azzam N.

    2016-10-01

    Three 26650 LiFePO4 (LFP) cells are cycled using a 40 A pulsed charge/discharge profile to study their performance in high rate pulsed applications. This profile is used to simulate naval pulsed power loads planned for deployment aboard future vessels. The LFP cells studied experienced an exponential drop in their usable high-rate recharge capacity within sixty cycles due to a rapid rise in their internal resistance. Differential capacitance shows that the voltage window for charge storage is pushed outside of the recommended voltage cutoff limits. Investigation into the state of health of the electrodes shows minimal loss of active material from the cathode to side reactions. Post-mortem examination of the anodic surface films reveals a large increase in the concentration of reduced salt compounds indicating that the pulsed profile creates highly favorable conditions for LiPF6 salt to break down into LiF. This film slows the ionic movement at the interface, affecting transfer kinetics, resulting in charge buildup in the bulk anode without successful energy storage. The results indicate that the use of these cells as a power supply for high pulsed power loads is hindered because of ionically resistant film development and not by an increasing rate of active material loss.

  11. Impact of Fluorescent Lighting on Oxidation of Model Wine Solutions Containing Organic Acids and Iron.

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    Grant-Preece, Paris; Barril, Celia; Schmidtke, Leigh M; Clark, Andrew C

    2017-03-22

    Previous studies have provided evidence that light exposure can increase oxygen consumption in wine and that the photodegradation of iron(III) tartrate could contribute to this process. In the present study, model wine solutions containing iron(III) and various organic acids, either alone or combined, were stored in sealed clear glass wine bottles and exposed to light from fluorescent lamps. Dissolved oxygen was monitored, and afterward the organic acid degradation products were determined and the capacity of the solutions to bind sulfur dioxide, the main wine preservative, was assessed. In the dark controls, little or no dissolved oxygen was consumed and the organic acids were stable. In the irradiated solutions, dissolved oxygen was consumed at a rate that was dependent on the specific organic acid present, and the latter were oxidized to various carbonyl compounds. For the solutions containing tartaric acid, malic acid, and/or citric acid, irradiation increased their sulfur dioxide-binding capacity.

  12. Age-related changes in laboratory values used in the diagnosis of anemia and iron deficiency.

    Science.gov (United States)

    Yip, R; Johnson, C; Dallman, P R

    1984-03-01

    Laboratory results from the Second National Health and Nutrition Examination Survey (NHANES II) were used to define age-related changes in laboratory values that are related to the diagnosis of anemia and iron deficiency. Analyses included Hb, hematocrit, red blood cell count, red cell indices, iron, total iron-binding capacity, transferrin saturation, and erythrocyte protoporphyrin. Computation of median values and 95% ranges by age and sex for each laboratory test were performed on 15,093 subjects between 1 and 74 yr of age who had complete laboratory data on venous blood, after excluding those subjects with an abnormality in one or more of three other laboratory tests. Age-related changes in laboratory measurements, such as those described herein, must be taken into consideration in order to optimize the identification of individuals with anemia and iron deficiency.

  13. Iron metabolism and oxidative profile of dogs naturally infected by Ehrlichia canis: Acute and subclinical disease.

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    Bottari, Nathieli B; Crivellenti, Leandro Z; Borin-Crivellenti, Sofia; Oliveira, Jéssica R; Coelho, Stefanie B; Contin, Catarina M; Tatsch, Etiane; Moresco, Rafael N; Santana, Aureo E; Tonin, Alexandre A; Tinucci-Costa, Mirela; Da Silva, Aleksandro S

    2016-03-01

    The aim of this study was to evaluate the oxidant profile and iron metabolism in serum of dogs infected by Ehrlichia canis. Banked sera samples of dogs were divided into two groups: negative control (n = 17) and infected by E. canis on acute (n = 24), and subclinical (n = 18) phases of the disease. The eritrogram, leucogram, and platelet counts were evaluate as well as iron, ferritin, and transferrin levels, latent iron binding capacity (LIBC), and transferrin saturation index (TSI) concentration. In addition, the advanced oxidation protein products (AOPP) and ferric reducing ability of plasma (FRAP) in sera were also analyzed. Blood samples were examined for the presence of E. canis by PCR techniques. History and clinical signals were recorded for each dog. During the acute phase of the disease, infected animals showed thrombocytopenia and anemia when compared to healthy animals (P canis showed changes in the iron metabolism and developed an oxidant status in consequence of disease pathophysiology.

  14. Evaluation of Erythrocytes, Platelets, and Serum Iron Profile in Dogs with Chronic Enteropathy

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    Veronica Marchetti

    2010-01-01

    Full Text Available The aim of this study is to evaluate iron status, erythrocyte, and platelet modifications in dogs with chronic enteropathy (CE. Dogs were grouped as food-responsive diarrhea (FRD, =11, antibiotic-responsive diarrhea (ARD, =5, and steroid-responsive diarrhea (SRD, =6 relating to therapeutic-response. Clinical and haematological findings, evidence of gastrointestinal blood loss, and iron metabolism were evaluated before and after treatment. A mild normocytic or microcytic anemia and thrombocytosis were identified, respectively in 18.0% and 31.8% of CE dogs. No significant differences between pre- and posttreatment of hematocrit, haemoglobin, and mean corpuscular volume, platelet count and mean platelet volume were found. Statistical analysis pointed out significant differences between pre- and posttreatment in serum iron (<.03 and unsaturated iron binding capacity (UIBC (<.01. No significant correlations were found between these parameters and canine Inflammatory Bowel Disease activity index and pattern of CE as well.

  15. Iron-rich drinking water and ascorbic acid supplementation improved hemolytic anemia in experimental Wistar rats.

    Science.gov (United States)

    Chaturvedi, Richa; Chattopadhyay, Pronobesh; Banerjee, Saumen; Bhattacharjee, Chira R; Raul, Prasanta; Borah, Kusum; Singh, Lokendra; Veer, Vijay

    2014-11-01

    Anemia is a frequent problem in both the primary and secondary health care programs. In contrast, most areas of northeast India are vulnerable to iron toxicity. In the present study, we documented the effect of administration of iron rich water on hemolytic anemia in a Wistar rats' animal model. Hemolytic anemia was induced by phenyl hydrazine through intraperitoneal route and diagnosed by the lowering of blood hemoglobin. After inducing the hemolytic anemia, 24 Wistar rats (n = 6 in four groups) were randomly assigned to 1 mg/l, 5 mg/l, and 10 mg/l ferric oxide iron along with 1 mg/ml ascorbic acid administered through drinking water; a control group was treated with iron-free water. The hematological and biochemical parameters, iron levels in liver, spleen, and kidney were estimated after 30 d of treatment. In the group treated with 5 mg/l iron and ascorbic acid, a significant increase of serum iron and ferritin, and a decrease of TIBC (total iron binding capacity) were observed without changes in other biochemical parameters and histopathological findings. However, in the group treated with 10 mg/l iron and ascorbic acid, hematological changes with significantly higher values for white blood cell count, serum glutamic phospho transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, glucose, splenic, and liver iron content, indicate potential toxicity at this supplementation level. Data suggest that the optimum concentration of iron (5 mg/l) and ascorbic acid solution may improve anemic conditions and may be therapeutically beneficial in the treatment of iron deficiency anemia without any negative impact, while 10 mg/l in drinking water seems to be the threshold for the initiation of toxicity.

  16. Efficacy of curcuminoids in alleviation of iron overload and lipid peroxidation in thalassemic mice.

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    Thephinlap, C; Phisalaphong, C; Fucharoen, S; Porter, J B; Srichairatanakool, S

    2009-09-01

    Non-transferrin bound iron (NTBI) is detectable in plasma of beta-thalassemia patients and participates in free-radical formation and oxidative tissue damage. Desferrioxamine (DFO), deferiprone (DFP) and deferasirox (DFX) are iron chelators used for treatment of iron overload; however they may cause adverse effects. Curcuminoids (CUR) exhibits many pharmacological activities and presents beta-diketone group to bind metal ions. Iron-chelating capacity of CUR was investigated in thalassemic mice. The mice (C57BL/6 stain); wild type ((mu)beta(+/+)) and heterozygous beta-knockout ((mu)beta(th-3/+)) were fed with ferrocene-supplemented diet for 2 months, and coincidently intervened with CUR (200 mg/kg/day) and DFP (50 mg/kg/day). Plasma NTBI was quantified using NTA chelation/HPLC method, and MDA concentration was analyzed by TBARS-based HPLC. Hepatic iron content (HIC) and total glutathione concentration were measured colorimetrically. Tissue iron accumulation was determined by Perl's staining. Ferrocene-supplemented diet induced occurrence of NTBI in plasma of thalassemic mice as well as markedly increased iron deposition in spleen and liver. Treatment with CUR and DFP decreased levels of the NTBI and MDA effectively. Hepatic MDA and nonheme iron content was also decreased in liver of the treated mice whilst total glutathione levels were increased. Importantly, the CUR and DFP reduced liver weight index and iron accumulation. Clearly, CUR is effective in chelation of plasma NTBI in iron-loaded thalassemic mice. Consequently, it can alleviate iron toxicity and harmfulness of free radicals. In prospective, efficacy of curcumin in removal of labile iron pool (LIP) in hepatocytes and cardiomyocytes are essential for investigation.

  17. Prominent IgE-binding and cytokine-inducing capacities of a newly cloned N-terminal region of Der f 14, an apolipophorin-like house dust mite allergen.

    Science.gov (United States)

    ElRamlawy, Kareem Gamal; Fujimura, Takashi; Aki, Tsunehiro; Okada, Akiyasu; Suzuki, Takayuki; Abe, Takuya; Hayashi, Takaharu; Epton, Michael J; Thomas, Wayne R; Rafeet, Inas Hussein; Al-Azhary, Diaa Beshr; Ono, Kazuhisa; Kawamoto, Seiji

    2017-09-11

    We previously characterized a 177 kDa allergen, M-177, from Dermatophagoides farinae. Thereafter, a counterpart to M-177 for Euroglyphus maynei was cloned as Eur m 14, and its sequence revealed that two environmental allergens, Mag 1 and Mag 3, are digested fragments of M-177. The aims of this study were to clone the cDNA of Der f 14 corresponding to M-177 and to elucidate the allergenic capacities of the N-terminal fragment of Der f 14 (Der f 14-N). Recombinant allergens were produced as trigger-factor-fused proteins in Escherichia coli. Der f 14-N showed the highest IgE-binding frequency among Der f 14-derived fragments in patients allergic to house dust mite by enzyme-linked immunosorbent assay. Der f 14-N showed the highest capacity to induce cell proliferation in murine lymphocyte and human peripheral mononuclear cells among Der f 14-derived fragments. Der f 14-N induced IL-13, IFN-γ, and IL-17 production more than Der f 1 and Der f 2 in mouse, and induced IL-5 and IFN-γ production at levels comparable to those of Der f 1 and Der f 2 in some patients. The high prevalence of IgE binding to the Der f 14-N indicates that it could be an important mite allergen. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  18. of iron deficiency in adolescent female athletes

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    J Malczewska-Lenczowska

    2017-04-01

    Full Text Available The aim of this study was to analyse the effectiveness of new haematology parameters related to reticulocytes and mature red blood cells to differentiate pre latent and latent iron deficiency. The study included 219 female athletes (aged 15-20 years representing volleyball, handball, cycling, canoeing, cross-country skiing, swimming and judo. To assess iron status the concentration of ferritin, soluble transferrin receptor (sTfR, iron and total iron binding capacity (TIBC were determined in serum. In addition to blood morphology, the mean cellular haemoglobin content in erythrocytes (CH and reticulocytes (CHr, mean cellular haemoglobin concentration in reticulocytes (CHCMr, the percentage of erythrocytes (HYPOm and reticulocytes (HYPOr with decreased cellular haemoglobin concentration, the percentage of erythrocytes (LowCHm and reticulocytes (LowCHr with decreased cellular haemoglobin content, and percentage of erythrocytes with decreased volume (MICROm were determined. Subjects with ferritin <30 ng/ml were classified as having stage I (pre-latent iron deficiency (ID. The second stage (latent ID was diagnosed when low ferritin was accompanied by elevated sTfR and/or elevated TIBC values. The frequency of ID (without anaemia symptoms was high, amounting to 60% (stage I in 45%, stage II in 15% of subjects. In subjects with stage I ID significant changes in haematological variables concerned mainly reticulocytes: CHCMr (p<.001, CHr (p<.05, LowCHr (p<.05, HYPOr (p<.001 in comparison to normal iron stores. In athletes with latent ID, there were also significant changes (p<.001 in many indices of mature red blood cells, i.e. haemoglobin concentration (Hb, mean corpuscular haemoglobin (MCH, mean corpuscular haemoglobin concentration (MCHC, CH, %LowCHm, as well as %MICROm (p<.01 in relation to the group without iron deficiency. The main finding of this study was that the diminished or exhausted iron stores had already caused changes in reticulocytes

  19. The structural requirements of epitopes with IgE binding capacity demonstrated by three major allergens from fish, egg and tree pollen.

    Science.gov (United States)

    Elsayed, S; Apold, J; Holen, E; Vik, H; Florvaag, E; Dybendal, T

    1991-01-01

    Three major allergens from cod fish, egg white and tree pollen, were characterized by studies on their allergenic and antigenic structures. The major allergen of cod fish, Allergen M "parvalbumins pI 4.75", is composed of 113 amino acid residues with a molecular weight of 12,328 daltons. It comprised three domains, AB, CD and EF, consisting of 3 helices interspaced by one loop. Each of the loops of the CD and EF domains each coordinates one Ca2+. The antigenicity and allergenicity of Allergen M was deduced from studying the modified protein and some particular synthetic peptides. Three sites were encompassing IgE binding epitopes namely peptides 33-44, 65-74 and 88-96. A novel peptide (49-64), of the CD-domain, was demonstrated to be allergenically/antigenically active and cross reactive with birch pollen allergen, which incidentally was used as a negative control. This site encompassed two repetitive sequences (D-E-D-K) and (D-E-L-K), suggested to be mutually critical for the specificity of antibody binding. This hypothesis was reconfirmed by SPPS of several analogous peptides of region 39-64. Furthermore, peptide 88-103 of the EF-domain was similarly synthesized; it functioned as a monovalent hapten, blocking and not eliciting allergic reaction. Moreover, peptide 13-32 of domain AB, the non-calcium binding domain, was thoroughly tested. The results of PK inhibition showed clear activity and the peptide was found to function at the level of a divalent determinant. Ovalbumin (OA) is the most dominant of five major allergens of egg white and universally used as model protein. OA allergenic epitopes were shown to be mainly determined by the primary structure and depend on certain peptide chain length. The N-terminal decapeptide (OA 1-10) was shown to react with reaginic IgE. Direct skin test on egg allergic patients, showed no activity and the site was therefore concluded to encompasses one single Ig binding haptenic epitope. Peptide OA 323-339, was demonstrated to

  20. Effect of Low-Dose Ferrous Sulfate vs Iron Polysaccharide Complex on Hemoglobin Concentration in Young Children With Nutritional Iron-Deficiency Anemia: A Randomized Clinical Trial.

    Science.gov (United States)

    Powers, Jacquelyn M; Buchanan, George R; Adix, Leah; Zhang, Song; Gao, Ang; McCavit, Timothy L

    2017-06-13

    Iron-deficiency anemia (IDA) affects millions of persons worldwide, and is associated with impaired neurodevelopment in infants and children. Ferrous sulfate is the most commonly prescribed oral iron despite iron polysaccharide complex possibly being better tolerated. To compare the effect of ferrous sulfate with iron polysaccharide complex on hemoglobin concentration in infants and children with nutritional IDA. Double-blind, superiority randomized clinical trial of infants and children aged 9 to 48 months with nutritional IDA (assessed by history and laboratory criteria) that was conducted in an outpatient hematology clinic at a US tertiary care hospital from September 2013 through November 2015; 12-week follow-up ended in January 2016. Three mg/kg of elemental iron once daily as either ferrous sulfate drops or iron polysaccharide complex drops for 12 weeks. Primary outcome was change in hemoglobin over 12 weeks. Secondary outcomes included complete resolution of IDA (defined as hemoglobin concentration >11 g/dL, mean corpuscular volume >70 fL, reticulocyte hemoglobin equivalent >25 pg, serum ferritin level >15 ng/mL, and total iron-binding capacity serum ferritin level and total iron-binding capacity, adverse effects. Of 80 randomized infants and children (median age, 22 months; 55% male; 61% Hispanic white; 40 per group), 59 completed the trial (28 [70%] in ferrous sulfate group; 31 [78%] in iron polysaccharide complex group). From baseline to 12 weeks, mean hemoglobin increased from 7.9 to 11.9 g/dL (ferrous sulfate group) vs 7.7 to 11.1 g/dL (iron complex group), a greater difference of 1.0 g/dL (95% CI, 0.4 to 1.6 g/dL; P serum ferritin level increased from 3.0 to 15.6 ng/mL (ferrous sulfate) vs 2.0 to 7.5 ng/mL (iron complex) over 12 weeks, a greater difference of 10.2 ng/mL (95% CI, 6.2 to 14.1 ng/mL; P iron-binding capacity decreased from 501 to 389 μg/dL (ferrous sulfate) vs 506 to 417 μg/dL (iron complex) (a greater difference of -50 μg/dL [95

  1. Evaluation of the Efficiency of the Reticulocyte Hemoglobin Content on Diagnosis for Iron Deficiency Anemia in Chinese Adults

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    Jie Cai

    2017-05-01

    Full Text Available Our aim was to evaluate the cut-off value and efficiency of using reticulocyte hemoglobin content as a marker to diagnose iron deficiency anemia in Chinese adults. 140 adults who needed bone marrow aspiration for diagnosis at the hematology department of the Peking Union Medical College Hospital were enrolled according to the inclusive and exclusive criteria. Venous blood samples were collected to detect complete blood count, including hemoglobin, reticulocyte hemoglobin content, hematocrit, mean cellular volume, corpuscular hemoglobin concentration, hemoglobin content, free erythrocyte protoporphyrin; iron indexes of serum ferritin, serum transferrin receptor, and unsaturated iron-binding capacity; and inflammation markers of C-reactive protein and α-acid glycoprotein. Bone marrow samples were obtained for the bone marrow iron staining, which was used as the standard for the evaluation of iron status in this study. Subjects were divided into three groups according to hemoglobin levels and bone marrow iron staining results: the IDA (iron deficiency anemia group, the NIDA (non-iron deficiency anemia group, and the control group. The differences of the above-mentioned indexes were compared among the three groups and the effect of inflammation was also considered. The cut-off value of reticulocyte hemoglobin content was determined by receiver operation curves. The IDA group (n = 56 had significantly lower reticulocyte hemoglobin content, mean cellular volume, corpuscular hemoglobin concentration, hemoglobin content, and serum ferritin; and higher free erythrocyte protoporphyrin, unsaturated iron-binding capacity, and serum transferrin receptor (p < 0.05 compared with the NIDA group (n = 38 and control group (n = 46. Hematocrit, serum ferritin, and unsaturated iron-binding capacity were significantly affected by inflammation while reticulocyte hemoglobin content and other parameters were not. The cut-off value of reticulocyte hemoglobin content for

  2. Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism.

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    Richard D Horniblow

    Full Text Available Alginates are a class of biopolymers with known iron binding properties which are routinely used in the fabrication of iron-oxide nanoparticles. In addition, alginates have been implicated in influencing human iron absorption. However, the synthesis of iron oxide nanoparticles employs non-physiological pH conditions and whether nanoparticle formation in vivo is responsible for influencing cellular iron metabolism is unclear. Thus the aims of this study were to determine how alginate and iron interact at gastric-comparable pH conditions and how this influences iron metabolism. Employing a range of spectroscopic techniques under physiological conditions alginate-iron complexation was confirmed and, in conjunction with aberration corrected scanning transmission electron microscopy, nanoparticles were observed. The results infer a nucleation-type model of iron binding whereby alginate is templating the condensation of iron-hydroxide complexes to form iron oxide centred nanoparticles. The interaction of alginate and iron at a cellular level was found to decrease cellular iron acquisition by 37% (p < 0.05 and in combination with confocal microscopy the alginate inhibits cellular iron transport through extracellular iron chelation with the resulting complexes not internalised. These results infer alginate as being useful in the chelation of excess iron, especially in the context of inflammatory bowel disease and colorectal cancer where excess unabsorbed luminal iron is thought to be a driver of disease.

  3. Association between iron deficiency anemia and febrile seizure in children.

    Science.gov (United States)

    Derakhshanfar, Hojjat; Abaskhanian, Ali; Alimohammadi, Hosein; ModanlooKordi, Mona

    2012-08-01

    Febrile convulsion (FC) is a common cause of seizure in young children, with an excellent prognosis. In addition to genetic predisposition, FCs are generally thought to be induced by elemental changes such as iron deficiency. Regarding the high prevalence of febrile seizure and iron deficiency anemia in children, the aim was to investigate the role of iron deficiency anemia in FC patients. This case-control study was performed in 500 children with febrile seizures (case) and 500 febrile children without seizures (control), referred to Mofid hospital in Tehran during one year (Nov 2009-Nov 2010). All children were aged between 6-60 months. The groups were matched in age and gender and use of supplemental iron. Laboratory tests consisted of Complete Blood Count (CBC). Serum iron, plasma ferritin and Total Iron Binding Capacity (TIBC) analyses were done in each patient. The patients and controls were 26.49+12.65 and 26.84+11.70 months of mean age, respectively. The amount of Hb, Hct, MCV, MCH, MCHC, RBC count, serum iron and plasma ferritin were significantly higher and TIBC was significantly lower among the cases with febrile convulsion than the controls. The incidence of iron deficiency anemia was significantly higher in controls compared with the cases (p less than 0.016). The mean of temperature peak on admission was significantly higher in the febrile convulsion group than controls. The results of this study suggest that the risk of febrile seizure occurrence in anemic children is less common as compared to non-anemic ones.

  4. Trend overtime of total haemoglobin, iron metabolism and trace minerals in veal calves fed high amounts of two different solid feeds

    Directory of Open Access Journals (Sweden)

    Anna-Lisa Stefani

    2010-01-01

    Full Text Available Fifty Polish Friesian veal calves were administrated high amounts of two different solid feeds (maize grain and a mix diet containing 10% of straw and 8% of soy in addition to the traditional milk replacer diet. Compared to the mix diet, maize grain had a lower content of iron, copper and zinc and a minor fibre level. Effects of the two diets on calves’ blood haemoglobin, iron, iron metabolism parameters, copper and zinc concentrations were studied. Haemoglobin concentration resulted higher at the end of the fattening for calves fed the mix diet, as expected. Values remained, however, within ranges that allowed acceptable carcass paleness. Haematic iron, unsaturated iron binding capacity (UIBC and total iron binding capacity (TIBC levels were not significantly different between the two solid feeds. Lower copper and zinc blood concentrations resulted for calves fed the mix diet were likely due to the feed fibre interfering with the bioavailability of the two minerals, according to what happens for iron.

  5. Determination of binding capacity and adsorption enthalpy between Human Glutamate Receptor (GluR1) peptide fragments and kynurenic acid by surface plasmon resonance experiments.

    Science.gov (United States)

    Csapó, E; Majláth, Z; Juhász, Á; Roósz, B; Hetényi, A; Tóth, G K; Tajti, J; Vécsei, L; Dékány, I

    2014-11-01

    The interaction between kynurenic acid (KYNA) and two peptide fragments (ca. 30 residues) of Human Glutamate Receptor 201-300 (GluR1) using surface plasmon resonance (SPR) spectroscopy was investigated. Because of the medical interest in the neuroscience, GluR1 is one of the important subunits of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR). AMPARs are ionotoropic glutamate receptors, which are mediating fast synaptic transmission and are crucial for plasticity in the brain. On the other hand, KYNA has been suggested to have neuroprotective activity and it has been considered for apply in therapy in certain neurobiological disorders. In this article the adsorption of the GluR1201-230 and GluR1231-259 peptides were studied on gold biosensor chip. The peptides were chemically bonded onto the gold surface via thiol group of L-cysteine resulted in the formation of peptide monolayer on the SPR chip surface. Because the GluR1231-259 peptide does not contain L-cysteine the Val256 was replaced by Cys256. The cross sectional area and the surface orientation of the studied peptides were determined by SPR and theoretical calculations (LOMETS) as well. The binding capability of KYNA on the peptide monolayer was studied in the concentration range of 0.1-5.0 mM using 150 mM NaCl ionic strength at pH 7.4 (±0.02) in phosphate buffer solutions. In order to determine the binding enthalpy the experiments were carried out between +10°C and +40°C. The heat of adsorption was calculated by using adsorption isotherms at different surface loading of KYNA on the SPR chip.

  6. The role of amino acid electron-donor/acceptor atoms in host-cell binding peptides is associated with their 3D structure and HLA-binding capacity in sterile malarial immunity induction

    Energy Technology Data Exchange (ETDEWEB)

    Patarroyo, Manuel E., E-mail: mepatarr@mail.com [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia); Universidad Nacional de Colombia, Bogota (Colombia); Almonacid, Hannia; Moreno-Vranich, Armando [Fundacion Instituto de Inmunologia de Colombia (FIDIC), Bogota (Colombia)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Fundamental residues located in some HABPs are associated with their 3D structure. Black-Right-Pointing-Pointer Electron-donor atoms present in {beta}-turn, random, distorted {alpha}-helix structures. Black-Right-Pointing-Pointer Electron-donor atoms bound to HLA-DR53. Black-Right-Pointing-Pointer Electron-acceptor atoms present in regular {alpha}-helix structure bound to HLA-DR52. -- Abstract: Plasmodium falciparum malaria continues being one of the parasitic diseases causing the highest worldwide mortality due to the parasite's multiple evasion mechanisms, such as immunological silence. Membrane and organelle proteins are used during invasion for interactions mediated by high binding ability peptides (HABPs); these have amino acids which establish hydrogen bonds between them in some of their critical binding residues. Immunisation assays in the Aotus model using HABPs whose critical residues had been modified have revealed a conformational change thereby enabling a protection-inducing response. This has improved fitting within HLA-DR{beta}1{sup Asterisk-Operator} molecules where amino acid electron-donor atoms present in {beta}-turn, random or distorted {alpha}-helix structures preferentially bound to HLA-DR53 molecules, whilst HABPs having amino acid electron-acceptor atoms present in regular {alpha}-helix structure bound to HLA-DR52. This data has great implications for vaccine development.

  7. Co-localization of iron binding on silica with p62/sequestosome1 (SQSTM1) in lung granulomas of mice with acute silicosis

    Science.gov (United States)

    Shimizu, Yasuo; Dobashi, Kunio; Nagase, Hiroyuki; Ohta, Ken; Sano, Takaaki; Matsuzaki, Shinichi; Ishii, Yoshiki; Satoh, Takahiro; Koka, Masashi; Yokoyama, Akihito; Ohkubo, Takeru; Ishii, Yasuyuki; Kamiya, Tomihiro

    2015-01-01

    The cellular mechanisms involved in the development of silicosis have not been fully elucidated. This study aimed to examine influence of silica-induced lung injury on autophagy. Suspensions of crystalline silica particles were administered transnasally to C57BL/6j mice. Immunohistochemical examination for Fas and p62 protein expression was performed using lung tissue specimens. Two-dimensional and quantitative analysis of silica deposits in the lungs were performed in situ using lung tissue sections by an in-air microparticle induced X-ray emission (in-air micro-PIXE) analysis system, which was based on irrradiation of specimens with a proton ion microbeam. Quantitative analysis showed a significant increase of iron levels on silica particles (assessed as the ratio of Fe relative to Si) on day 56 compared with day 7 (p<0.05). Fas and p62 were expressed by histiocytes in granulomas on day 7, and the expressions persisted for day 56. Fas- and p62-expressing histiocytes were co-localized in granulomas with silica particles that showed an increase of iron levels on silica particles in mouse lungs. Iron complexed with silica induces apoptosis, and may lead to dysregulations of autophagy in histiocytes of granulomas, and these mechanisms may contribute to granuloma development and progression in silicosis. PMID:25834305

  8. The Regulation of Iron Absorption and Homeostasis

    Science.gov (United States)

    Wallace, Daniel F

    2016-01-01

    Iron is an essential element in biology, required for numerous cellular processes. Either too much or too little iron can be detrimental, and organisms have developed mechanisms for balancing iron within safe limits. In mammals there are no controlled mechanisms for the excretion of excess iron, hence body iron homeostasis is regulated at the sites of absorption, utilisation and recycling. This review will discuss the discoveries that have been made in the past 20 years into advancing our understanding of iron homeostasis and its regulation. The study of iron-associated disorders, such as the iron overload condition hereditary haemochromatosis and various forms of anaemia have been instrumental in increasing our knowledge in this area, as have cellular and animal model studies. The liver has emerged as the major site of systemic iron regulation, being the location where the iron regulatory hormone hepcidin is produced. Hepcidin is a negative regulator of iron absorption and recycling, achieving this by binding to the only known cellular iron exporter ferroportin and causing its internalisation and degradation, thereby reducing iron efflux from target cells and reducing serum iron levels. Much of the research in the iron metabolism field has focussed on the regulation of hepcidin and its interaction with ferroportin. The advances in this area have greatly increased our knowledge of iron metabolism and its regulation and have led to the development of novel diagnostics and therapeutics for iron-associated disorders.

  9. Iron deficiency anemia in a ring-tailed lemur (Lemur catta) with concurrent chronic renal failure.

    Science.gov (United States)

    Anderson, Kadie M; Wolf, Karen N

    2014-02-15

    A 16-year-old vasectomized male ring-tailed lemur (Lemur catta) with a history of suspected chronic renal failure was evaluated because of extreme lethargy, hyperpnea, and abscess of the right pectoral scent gland. Examination of the anesthetized patient revealed an impacted right pectoral scent gland with serosanguineous exudate. A CBC and serum biochemical analysis revealed severe anemia, marked azotemia, hyperphosphatemia, and hypocalcemia. Supportive care (including fluid therapy and phosphorus binder administration) was initiated for renal failure; the affected gland was cleaned, and antimicrobials were administered. The patient received 1 blood transfusion, and darbepoetin alfa was administered weekly to stimulate RBC production. Anemia and azotemia persisted. Three months after treatment started, serum iron analysis revealed that iron deficiency was the probable cause for the lack of a consistent regenerative response to darbepoetin injections. Iron dextran injections resulted in a marked regenerative response; however, serum biochemical analysis results after the second injection were consistent with hepatic injury. Hepatic enzyme activities normalized following discontinuation of iron dextran treatment, but the lemur's Hct declined rapidly despite supplementary iron administration PO. The patient developed severe mandibular osteomyelitis and was euthanized because of poor prognosis. Postmortem evaluation of hepatic iron concentration confirmed iron deficiency. The family Lemuridae is considered prone to hemosiderosis and hemochromatosis, which delayed rapid diagnosis and treatment of the lemur's disease. Apparent hepatic injury following iron dextran injections further complicated treatment. Findings for this lemur support the use of species-specific total iron binding capacity and total serum iron and ferritin concentrations in evaluation of an animal with suspected iron deficiency.

  10. Assessment of Iron Overload in Homozygous and Heterozygous Beta Thalassemic Children below 5 Years of Age

    Directory of Open Access Journals (Sweden)

    Dhiraj J. Trivedi

    2014-07-01

    Full Text Available Background: Thalassemia is a genetic disease having 3-7% carrier rate in Indians. It is transfusion dependent anemia having high risk of iron overloading. A clinical symptom of iron overload becomes detectable in second decade causing progressive liver, heart and endocrine glands damage. There is a need to assess iron overload in thalassemics below 5 years of age to protect them from complications at later age of life. Aims and objectives: Present study was undertaken to estimate serum iron status and evaluate serum transferrin saturation in both homozygous & heterozygous form of thalassemia as an index of iron overload among children of one to five years of age. Materials and Methods: Clinically diagnosed thirty cases of β thalassemia major & thirty cases of β thalassemia minor having severe anemia, hepatospleenomegaly and between 1 year to 5 years of age were included in study group and same age matched healthy controls were included in the study. RBC indices and HbA, HbA2 and HbF were estimated along with serum iron & serum Total Iron Binding Capacity (TIBC and serum transferrin levels. Results: Significant difference was observed in hemoglobin levels between control and both beta thalassemia groups. Mean Corpuscular Volume (MCV and Mean Corpuscular Hemoglobin (MCH values were reduced. Hemoglobin electrophoresis showed the elevated levels of HbF and HbA2 in both beta thalassemia groups. Among serum iron parameters, serum iron, TIBC and transferrin saturation were elevated whereas serum transferrin levels were low in thalassemia major in children below 5 years of age. Conclusion: Although clinical symptoms of iron overload have been absent in thalassemic children below five years of age, biochemical iron overloading has started at much lower age which is of great concern.

  11. Impact of iron deficiency anemia on the function of the immune system in children

    Science.gov (United States)

    Hassan, Tamer Hasan; Badr, Mohamed Ahmed; Karam, Nehad Ahmed; Zkaria, Marwa; El Saadany, Hosam Fathy; Abdel Rahman, Doaa Mohamed; Shahbah, Doaa Abdallah; Al Morshedy, Salah Mohamed; Fathy, Manar; Esh, Asmaa Mohamed Hosni; Selim, Amal Mohamed

    2016-01-01

    Abstract The importance of iron deficiency as a public health problem is based ultimately on the seriousness of its consequences on health. The most extensively investigated consequences of iron deficiency involve work performance and immune function. The significance of the effects on work performance is generally accepted. In contrast, data on the influence of iron deficiency on immune function are often perceived as being confusing and contradictory. We aimed to evaluate the effect of iron deficiency anemia on humoral, cellular, nonspecific immunity, and also the effect on the cytokines that are the key factors of many immunologic steps. Forty children with iron deficiency anemia and 20 age and sex-matched healthy children were included. All children were subjected to full medical history, thorough clinical examination, complete blood count, iron indices (serum iron, serum total iron-binding capacity, serum ferritin, and transferrin saturation), immunoglobulin assay (IgA, IgG, and IgM), interleukin (IL)-6 serum level, study of T-lymphocyte subsets, and evaluation of phagocytic function of macrophages and oxidative burst activity of neutrophils. Patients had significantly lower IgG levels, IL-6, phagocytic activity, and oxidative burst of neutrophils than controls, although there was no significant difference between patients and controls with regard to other immunoglobulins and CD4/CD8 ratio. There was significantly positive correlation between serum iron and IL-6 serum level. We concluded that humoral, nonspecific immunity (phagocytic activity and oxidative burst), and the IL-6 are influenced in patients with iron deficiency anemia. Study of these abnormalities after correction of iron deficiency is strongly needed. PMID:27893677

  12. Impact of iron deficiency anemia on the function of the immune system in children.

    Science.gov (United States)

    Hassan, Tamer Hasan; Badr, Mohamed Ahmed; Karam, Nehad Ahmed; Zkaria, Marwa; El Saadany, Hosam Fathy; Abdel Rahman, Doaa Mohamed; Shahbah, Doaa Abdallah; Al Morshedy, Salah Mohamed; Fathy, Manar; Esh, Asmaa Mohamed Hosni; Selim, Amal Mohamed

    2016-11-01

    The importance of iron deficiency as a public health problem is based ultimately on the seriousness of its consequences on health. The most extensively investigated consequences of iron deficiency involve work performance and immune function. The significance of the effects on work performance is generally accepted. In contrast, data on the influence of iron deficiency on immune function are often perceived as being confusing and contradictory.We aimed to evaluate the effect of iron deficiency anemia on humoral, cellular, nonspecific immunity, and also the effect on the cytokines that are the key factors of many immunologic steps.Forty children with iron deficiency anemia and 20 age and sex-matched healthy children were included. All children were subjected to full medical history, thorough clinical examination, complete blood count, iron indices (serum iron, serum total iron-binding capacity, serum ferritin, and transferrin saturation), immunoglobulin assay (IgA, IgG, and IgM), interleukin (IL)-6 serum level, study of T-lymphocyte subsets, and evaluation of phagocytic function of macrophages and oxidative burst activity of neutrophils.Patients had significantly lower IgG levels, IL-6, phagocytic activity, and oxidative burst of neutrophils than controls, although there was no significant difference between patients and controls with regard to other immunoglobulins and CD4/CD8 ratio. There was significantly positive correlation between serum iron and IL-6 serum level.We concluded that humoral, nonspecific immunity (phagocytic activity and oxidative burst), and the IL-6 are influenced in patients with iron deficiency anemia. Study of these abnormalities after correction of iron deficiency is strongly needed.

  13. Nonalcoholic steatohepatitis in Asian Indians is neither associated with iron overload nor with HFE gene mutations

    Institute of Scientific and Technical Information of China (English)

    Ajay Duseja; Reena Das; Mohit Nanda; Ashim Das; Gurjeewan Garewal; Yogesh Chawla

    2005-01-01

    AIM: The pathogenesis of occurrence of liver inflammation and fibrosis in patients with nonalcoholic steatohepatitis (NASH) is not completely understood. Other than insulin resistance, iron abnormalities have been thought to be one of the triggering factors. Therefore, our aim was to study the role of iron abnormalities and HFE gene mutations in patients with NASH.METHODS: Thirty-one patients of NASH diagnosed on the basis of clinical examination biochemistry, ultrasonography and liver biopsy (n = 14) were included in the study. Serum iron parameters (n = 23) (iron, ferritin, total iron-binding capacity and transferrin saturation), Peris' iron staining on liver biopsies (n = 14) and HFE gene mutations (C282Y and H63D) (n = 16) were studied in these patients. The association between iron staining, necroinflammatory activity and fibrosis stage on liver biopsies was also determined.RESULTS: Elevated serum iron, ferritin and transferrin saturation above 55% were observed in 4.3% of patients.On histology, 71% of the patients had negative iron staining,21.4% had 1+ staining, 7.2% had 2+ staining and none had 3+ or 4+ staining. There was no association between the degree of iron staining and necroinflammatory activity (P = 0.55) and fibrosis stage (P = 0.09) on histology. None of the patients had C282Y HFE gene mutation and four patients (25%) were found to be heterozygotes for H63D gene mutation.CONCLUSION: Our study does not favor iron overload and HFE gene mutations as major factors in the pathogenesis of NASH in Asian Indians.

  14. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore......, this paper presents methods to analyze station capacity. Four methods to analyze station capacity are developed. The first method is an adapted UIC 406 capacity method that can be used to analyze switch zones and platform tracks at stations that are not too complex. The second method examines the need...... the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station...

  15. Relationship between Serum Iron Profile and Blood Groups among the Voluntary Blood Donors of Bangladesh.

    Science.gov (United States)

    Hoque, M M; Adnan, S D; Karim, S; Al-Mamun, M A; Faruki, M A; Islam, K; Nandy, S

    2016-04-01

    Blood donation results in a substantial iron loss and subsequent mobilization from body stores. Chronic iron deficiency is a well-recognized complication of regular blood donation. The present study conducted to compare the level of serum ferritin, serum iron, total iron binding capacity (TIBC) and percentage transferrin saturation in different ABO and Rhesus type blood groups among the voluntary blood donors of Bangladesh. The present prospective study included 100 healthy voluntary donors attending at Department of Blood Transfusion, Dhaka Medical College, Dhaka between the periods of July 2013 to Jun 2014. From each donor 10mL venous blood sample was taken and divided into heparinized and non-heparinized tubes for determination of hemoglobin (Hb), hematocrit (Hct), serum iron (SI), total iron binding capacity (TIBC) and serum ferritin by standard laboratory methods. Percentage of transferrin saturation (TS) calculated from serum iron and TIBC. Data were analyzed with SPSS (version 16) software and comparisons between groups were made using student's t-test and one way ANOVA. In the present study mean±SD of age of the respondents was 27.2±6.5 years with a range of 18 to 49 years and 81.0% were male and 19.0% were female. Among the donors 18.0% had blood group A, 35.0% had blood group B, 14.0% had blood group AB and 33.0% had blood group O. Among the donors 91.0% had rhesus positive and 9.0% had rhesus negative. Donors with blood group O had lowest haemoglobin, serum iron and transferring saturation levels. Donors with blood group A had highest TIBC level. Donors with blood group B had lowest serum ferritin level. An independent samples 't' test showed statistically significant difference in serum ferritin and percentage transferrin saturation between blood group AB and blood group O and in percentage transferrin saturation between blood group B and blood group O. One way ANOVA showed that there is no significant difference in haemoglobin, serum iron, serum

  16. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore......, this paper presents methods to analyze station capacity. Four methods to analyze station capacity are developed. The first method is an adapted UIC 406 capacity method that can be used to analyze switch zones and platform tracks at stations that are not too complex. The second method examines the need...... for platform tracks and the probability that arriving trains will not get a platform track immediately at arrival. The third method is a scalable method that analyzes the conflicts in the switch zone(s). In its simplest stage, the method just analyzes the track layout while the more advanced stages also take...

  17. Elucidating the domain architecture and functions of non-core RAG1: The capacity of a non-core zinc-binding domain to function in nuclear import and nucleic acid binding

    Directory of Open Access Journals (Sweden)

    Zhao Shuying

    2011-05-01

    Full Text Available Abstract Background The repertoire of the antigen-binding receptors originates from the rearrangement of immunoglobulin and T-cell receptor genetic loci in a process known as V(DJ recombination. The initial site-specific DNA cleavage steps of this process are catalyzed by the lymphoid specific proteins RAG1 and RAG2. The majority of studies on RAG1 and RAG2 have focused on the minimal, core regions required for catalytic activity. Though not absolutely required, non-core regions of RAG1 and RAG2 have been shown to influence the efficiency and fidelity of the recombination reaction. Results Using a partial proteolysis approach in combination with bioinformatics analyses, we identified the domain boundaries of a structural domain that is present in the 380-residue N-terminal non-core region of RAG1. We term this domain the Central Non-core Domain (CND; residues 87-217. Conclusions We show how the CND alone, and in combination with other regions of non-core RAG1, functions in nuclear localization, zinc coordination, and interactions with nucleic acid. Together, these results demonstrate the multiple roles that the non-core region can play in the function of the full length protein.

  18. Site-directed immobilization of a genetically engineered anti-methotrexate antibody via an enzymatically introduced biotin label significantly increases the binding capacity of immunoaffinity columns.

    Science.gov (United States)

    Davenport, Kaitlynn R; Smith, Christopher A; Hofstetter, Heike; Horn, James R; Hofstetter, Oliver

    2016-05-15

    In this study, the effect of random vs. site-directed immobilization techniques on the performance of antibody-based HPLC columns was investigated using a single-domain camelid antibody (VHH) directed against methotrexate (MTX) as a model system. First, the high flow-through support material POROS-OH was activated with disuccinimidyl carbonate (DSC), and the VHH was bound in a random manner via amines located on the protein's surface. The resulting column was characterized by Frontal Affinity Chromatography (FAC). Then, two site-directed techniques were explored to increase column efficiency by immobilizing the antibody via its C-terminus, i.e., away from the antigen-binding site. In one approach, a tetra-lysine tail was added, and the antibody was immobilized onto DSC-activated POROS. In the second site-directed approach, the VHH was modified with the AviTag peptide, and a biotin-residue was enzymatically incorporated at the C-terminus using the biotin ligase BirA. The biotinylated antibody was subsequently immobilized onto NeutrAvidin-derivatized POROS. A comparison of the FAC analyses, which for all three columns showed excellent linearity (R(2)>0.999), revealed that both site-directed approaches yield better results than the random immobilization; the by far highest efficiency, however, was determined for the immunoaffinity column based on AviTag-biotinylated antibody. As proof of concept, all three columns were evaluated for quantification of MTX dissolved in phosphate buffered saline (PBS). Validation using UV-detection showed excellent linearity in the range of 0.04-12μM (R(2)>0.993). The lower limit of detection (LOD) and lower limit of quantification (LLOQ) were found to be independent of the immobilization strategy and were 40nM and 132nM, respectively. The intra- and inter-day precision was below 11.6%, and accuracy was between 90.7% and 112%. To the best of our knowledge, this is the first report of the AviTag-system in chromatography, and the first

  19. Label-Free LC-MS Profiling of Skeletal Muscle Reveals Heart-Type Fatty Acid Binding Protein as a Candidate Biomarker of Aerobic Capacity.

    Science.gov (United States)

    Malik, Zulezwan Ab; Cobley, James N; Morton, James P; Close, Graeme L; Edwards, Ben J; Koch, Lauren G; Britton, Steven L; Burniston, Jatin G

    2013-12-01

    Two-dimensional gel electrophoresis provides robust comparative analysis of skeletal muscle, but this technique is laborious and limited by its inability to resolve all proteins. In contrast, orthogonal separation by SDS-PAGE and reverse-phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) affords deep mining of the muscle proteome, but differential analysis between samples is challenging due to the greater level of fractionation and the complexities of quantifying proteins based on the abundances of their tryptic peptides. Here we report simple, semi-automated and time efficient (i.e., 3 h per sample) proteome profiling of skeletal muscle by 1-dimensional RPLC electrospray ionisation tandem MS. Solei were analysed from rats (n = 5, in each group) bred as either high- or low-capacity runners (HCR and LCR, respectively) that exhibited a 6.4-fold difference (1,625 ± 112 m vs. 252 ± 43 m, p ions, which spanned three orders of magnitude. In total, 207 proteins were analysed, which encompassed almost all enzymes of the major metabolic pathways in skeletal muscle. The most abundant protein detected was type I myosin heavy chain (RA = 5,843 ± 897) and the least abundant protein detected was heat shock 70 kDa protein (RA = 2 ± 0.5). Sixteen proteins were significantly (p ion (551.21 m/z) of the doubly-charged peptide SLGVGFATR (454.19 m/z) of residues 23-31 of FABPH. SRM was conducted on technical replicates of each biological sample and exhibited a coefficient of variation of 20%. The abundance of FABPH measured by SRM was 2.84-fold greater (p = 0.0095) in HCR muscle. In addition, SRM of FABPH was performed in vastus lateralis samples of young and elderly humans with different habitual activity levels (collected during a previous study) finding FABPH abundance was 2.23-fold greater (p = 0.0396) in endurance-trained individuals regardless of differences in age. In summary, our findings in HCR/LCR rats provide protein-level confirmation for earlier

  20. Shigella Iron Acquisition Systems and their Regulation.

    Science.gov (United States)

    Wei, Yahan; Murphy, Erin R

    2016-01-01

    Survival of Shigella within the host is strictly dependent on the ability of the pathogen to acquire essential nutrients, such as iron. As an innate immune defense against invading pathogens, the level of bio-available iron within the human host is maintained at exceeding low levels, by sequestration of the element within heme and other host iron-binding compounds. In response to sequestration mediated iron limitation, Shigella produce multiple iron-uptake systems that each function to facilitate the utilization of a specific host-associated source of nutrient iron. As a mechanism to balance the essential need for iron and the toxicity of the element when in excess, the production of bacterial iron acquisition systems is tightly regulated by a variety of molecular mechanisms. This review summarizes the current state of knowledge on the iron-uptake systems produced by Shigella species, their distribution within the genus, and the molecular mechanisms that regulate their production.

  1. Hepcidin: regulation of the master iron regulator

    Science.gov (United States)

    Rishi, Gautam; Wallace, Daniel F.; Subramaniam, V. Nathan

    2015-01-01

    Iron, an essential nutrient, is required for many diverse biological processes. The absence of a defined pathway to excrete excess iron makes it essential for the body to regulate the amount of iron absorbed; a deficiency could lead to iron deficiency and an excess to iron overload and associated disorders such as anaemia and haemochromatosis respectively. This regulation is mediated by the iron-regulatory hormone hepcidin. Hepcidin binds to the only known iron export protein, ferroportin (FPN), inducing its internalization and degradation, thus limiting the amount of iron released into the blood. The major factors that are implicated in hepcidin regulation include iron stores, hypoxia, inflammation and erythropoiesis. The present review summarizes our present knowledge about the molecular mechanisms and signalling pathways contributing to hepcidin regulation by these factors. PMID:26182354

  2. CORRELATION OF GALLSTONE FORMATION WITH SERUM IRON LEVELS

    Directory of Open Access Journals (Sweden)

    Rohini Bipin Bhadre

    2016-07-01

    Full Text Available INTRODUCTION Gallstones are one of the most common problem associated with the gallbladder, affecting millions of people throughout the world. Bile is excreted from liver and gallbladder into Duodenum for digestion. After digestion, if the gallbladder is not emptied out completely, the Bile Juice that remains in the gallbladder can become too concentrated with cholesterol leading to gallstone formation. Cholesterol and calcium bilirubinate are the two main substances involved in gallstone formation. Gallstones derived from bile consists of mixture of cholesterol, bilirubin with or without calcium. Based on their chemical composition, gallstones found in the gallbladder are classified as cholesterol, pigmented or mixed stones. Iron deficiency has been shown to alter the activity of several hepatic enzymes, leading to increased gallbladder bile cholesterol saturation and promotion of cholesterol crystal formation. AIMS & OBJECTIVE Attempt to establish a correlation with gallstones and decreased serum iron levels. MATERIAL & METHODS This study was a prospective cohort study which included 100 consecutive patients with imaging studies suggestive of Cholelithiasis. The Gallstone surgically removed was crushed with mortar and pestle and then analysed for cholesterol, calcium, phosphate and bilirubin (pigment. Serum samples were analysed for Cholesterol, iron and iron binding capacity. RESULTS 86% patients had increased cholesterol levels (p=0.04 and 93% had decreased serum Iron levels (p=0.96. The most common type of gallstone was found to be Cholesterol type of gallstone followed by Mixed and Pigment gallstones. CONCLUSION Serum cholesterol levels were found to be raised in majority of the patients and serum iron was found to be low in these majority of the patients indicating iron deficiency may play a role in gallstone formation.

  3. Influence of magnesium on biochemical parameters of iron and oxidative stress in patients with type 2 diabetes

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    Fabiane Araùjo Sampaio

    Full Text Available Introduction: Studies have shown that oxidative stress, found in patients with type 2 diabetes, may be due to changes in the metabolism of minerals, such as magnesium and iron. Data related to compartmentalization of these minerals in diabetes are scarce and controversial. Objective: This study assessed the influence of magnesium on biochemical parameters of iron and oxidative stress in patients with type 2 diabetes. Methods: A case-control study in male and female subjects aged 27-59 years, divided into two groups: type 2 diabetes (n=40 and control (n=48. Intake of magnesium and iron was assessed by three-day food record. Plasma, erythrocyte and urinary levels of magnesium, serum iron, ferritin, total iron binding capacity, fasting glucose, glycated hemoglobin, insulin, creatinine clearance and plasma thiobarbituric acid reactive substances (TBARS were analyzed. Results and Discussion: Magnesium intake and plasma magnesium were lower in diabetic subjects. There was low urinary magnesium excretion, with no difference between groups. Although normal, the diabetic group had lower serum iron and ferritin concentrations compared to control subjects. Plasma TBARS in diabetic patients was higher than control while creatinine clearance was lower. An inverse correlation between erythrocyte magnesium and serum iron and ferritin was observed in the diabetes group. Conclusions: Diabetes induced hypomagnesemia and this, associated with chronic hyperglycemia, may have enhanced oxidative stress. Erythrocyte magnesium may have contributed to prevent iron overload and worsening of oxidative stress and hyperglycemic status.

  4. Importance of chemical binding type between As and iron-oxide on bioaccessibility in soil: Test with synthesized two line ferrihydrite

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Seulki [Seoul Center, Korea Basic Science Institute, 6-7, Inchon-ro 22-gil, Seongbuk-gu, Seoul 02855 (Korea, Republic of); Yang, Kyung [Division of Public Infrastructure Assessment, Environmental Assessment Group, Korea Environmental Institute, Sejong 30147 (Korea, Republic of); Jho, Eun Hea [Department of Environmental Science, Hankuk University of Foreign Studies, 81 Oedae-ro, Mohyeonmyeon, Cheoin-gu, Yongin-si, Gyeonggi-do 17035 (Korea, Republic of); Nam, Kyoungphile, E-mail: kpnam@snu.ac.kr [Department of Civil and Environmental Engineering, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826 (Korea, Republic of)

    2017-05-15

    Highlights: • Arsenic (As)-adsorbed and As-coprecipiated two-line ferrihydrites were synthesized. • Bioaccessibility was closely related to chemical binding type of As in Fe oxide. • Chemical binding type needs to be considered to characterize the risk of As in soil. - Abstract: Bioaccessible concentrations of As associated with Fe oxide as different chemical binding types were determined in soils using the in vitro Physiologically Based Extraction Test (PBET). When compared to the five-step sequential extraction data, most of the As extracted by in vitro PBET originated from the amorphous Fe oxide-bound fraction, and more importantly, the bioaccessibility of As ranged from 0 to 58.8% in 24 soil samples. Two batches of ferrihydrite were synthesized separately. For one batch, As was adsorbed onto the ferrihydrite after synthesis; for the other one, As was added while synthesizing ferrihydrite to co-precipitate. The bioaccessible concentration of As determined by in vitro PBET of the former was 415 mg of As/kg of ferrihydrite and that of the latter was 67 mg of As/kg of ferrihydrite. X-ray photoelectron spectra (XPS) analysis indicated that As–O–Fe bonds were evident in As-associated ferrihydrite sample and especially, As was found within the Fe oxide lattice in the co-precipitated sample. Our data suggest that binding type between As and Fe oxide should be considered when determining the bioaccessibility of As in soil, which, in turn, greatly influences the realistic risk of As present in soil.

  5. Iron and cancer: more ore to be mined.

    Science.gov (United States)

    Torti, Suzy V; Torti, Frank M

    2013-05-01

    Iron is an essential nutrient that facilitates cell proliferation and growth. However, iron also has the capacity to engage in redox cycling and free radical formation. Therefore, iron can contribute to both tumour initiation and tumour growth; recent work has also shown that iron has a role in the tumour microenvironment and in metastasis. Pathways of iron acquisition, efflux, storage and regulation are all perturbed in cancer, suggesting that reprogramming of iron metabolism is a central aspect of tumour cell survival. Signalling through hypoxia-inducible factor (HIF) and WNT pathways may contribute to altered iron metabolism in cancer. Targeting iron metabolic pathways may provide new tools for cancer prognosis and therapy.

  6. A cascade of iron-containing proteins governs the genetic iron starvation response to promote iron uptake and inhibit iron storage in fission yeast.

    Directory of Open Access Journals (Sweden)

    Javier Encinar del Dedo

    2015-03-01

    Full Text Available Iron is an essential cofactor, but it is also toxic at high levels. In Schizosaccharomyces pombe, the sensor glutaredoxin Grx4 guides the activity of the repressors Php4 and Fep1 to mediate a complex transcriptional response to iron deprivation: activation of Php4 and inactivation of Fep1 leads to inhibition of iron usage/storage, and to promotion of iron import, respectively. However, the molecular events ruling the activity of this double-branched pathway remained elusive. We show here that Grx4 incorporates a glutathione-containing iron-sulfur cluster, alone or forming a heterodimer with the BolA-like protein Fra2. Our genetic study demonstrates that Grx4-Fra2, but not Fep1 nor Php4, participates not only in iron starvation signaling but also in iron-related aerobic metabolism. Iron-containing Grx4 binds and inactivates the Php4 repressor; upon iron deprivation, the cluster in Grx4 is probably disassembled, the proteins dissociate, and Php4 accumulates at the nucleus and represses iron consumption genes. Fep1 is also an iron-containing protein, and the tightly bound iron is required for transcriptional repression. Our data suggest that the cluster-containing Grx4-Fra2 heterodimer constitutively binds to Fep1, and upon iron deprivation the disassembly of the iron cluster between Grx4 and Fra2 promotes reverse metal transfer from Fep1 to Grx4-Fra2, and de-repression of iron-import genes. Our genetic and biochemical study demonstrates that the glutaredoxin Grx4 independently governs the Php4 and Fep1 repressors through metal transfer. Whereas iron loss from Grx4 seems to be sufficient to release Php4 and allow its nuclear accumulation, total or partial disassembly of the Grx4-Fra2 cluster actively participates in iron-containing Fep1 activation by sequestering its iron and decreasing its interaction with promoters.

  7. Native iron

    DEFF Research Database (Denmark)

    Brooks, Charles Kent

    2015-01-01

    , a situation unique in the Solar System. In such a world, iron metal is unstable and, as we all know, oxidizes to the ferric iron compounds we call 'rust'. If we require iron metal it must be produced at high temperatures by reacting iron ore, usually a mixture of ferrous (Fe2+) and ferric (Fe3+) oxides (Fe2O3......, hematite, or FeO.Fe2O3, magnetite), with carbon in the form of coke. This is carried out in a blast furnace. Although the Earth's core consists of metallic iron, which may also be present in parts of the mantle, this is inaccessible to us, so we must make our own. In West Greenland, however, some almost...... unique examples of iron metal, otherwise called 'native iron' or 'telluric iron', occur naturally....

  8. Iron deficiency and cardiovascular disease.

    Science.gov (United States)

    von Haehling, Stephan; Jankowska, Ewa A; van Veldhuisen, Dirk J; Ponikowski, Piotr; Anker, Stefan D

    2015-11-01

    Iron deficiency affects up to one-third of the world's population, and is particularly common in elderly individuals and those with certain chronic diseases. Iron excess can be detrimental in cardiovascular illness, and research has now also brought anaemia and iron deficiency into the focus of cardiovascular medicine. Data indicate that iron deficiency has detrimental effects in patients with coronary artery disease, heart failure (HF), and pulmonary hypertension, and possibly in patients undergoing cardiac surgery. Around one-third of all patients with HF, and more than one-half of patients with pulmonary hypertension, are affected by iron deficiency. Patients with HF and iron deficiency have shown symptomatic improvements from intravenous iron administration, and some evidence suggests that these improvements occur irrespective of the presence of anaemia. Improved exercise capacity has been demonstrated after iron administration in patients with pulmonary hypertension. However, to avoid iron overload and T-cell activation, it seems that recipients of cardiac transplantations should not be treated with intravenous iron preparations.

  9. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente

    2012-01-01

    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive...... carrying capacity (SCC) and assimilative carrying capacity (ACC). The act mandates that the latter two aspects must be taken into consideration in the local spatial plans. The present study aimed at developing a background for a national guideline for carrying capacity in Indonesian provinces and districts...... standard or governmental political objective exists. In most cases it was possible to select a set of indicators, including thresholds that are workable in a carrying capacity planning at the local administrative levels. Not all relevant sectors at the decentralized level were included. Indicators of SCC...

  10. A rare case of iron-pill induced gastritis in a female teenager: A case report and a review of the literature.

    Science.gov (United States)

    Meliţ, Lorena Elena; Mărginean, Cristina Oana; Mocanu, Simona; Mărginean, Maria Oana

    2017-07-01

    The treatment of iron-deficiency anemia with oral iron supplements can present side-effects on the GI tract mucosa including necrosis, ulceration, or ischemia. The particular endoscopic findings and the histopathological exam will establish the diagnosis of erosive gastritis with iron deposits in the gastric mucosa. We present the case of a 14-year-old female admitted in our clinic for upper digestive hemorrhage, nausea, melena, and abdominal pain. Her personal history revealed iron deficiency anemia receiving oral iron supplements for approximately 2 weeks. The laboratory tests at the moment of admission pointed out anemia, increased level of serum iron, increased liver transaminases, a decreased level of ferritin, but with normal levels of both total iron-binding capacity and transferrin. The eso-gastro-duodenoscopy revealed multiple brown deposits on the surface of the gastric mucosa and multiple hemorrhagic lesions, under the aspect of erosions all over the gastric mucosa, but more severe in the antral part, and the histopathological exam confirmed the presence of iron deposits at this level. Iron-pill induced gastritis is a rare, under-diagnosed entity that can be present even at pediatric ages with potential severe clinical impact.

  11. Comparison of short-term efficacy of iron sucrose with those of ferric chloride in hemodialysis patients: An open-label study

    Directory of Open Access Journals (Sweden)

    Po-Jen Hsiao

    2016-01-01

    Full Text Available Background: It is intriguing and imperative that the comparison of the iron preparations in hemodialysis (HD patients. This study aimed to observe the short-term efficacy of parenteral iron sucrose and ferric chloride in HD patients . Materials and Methods: This was a consecutive 10-week single-blind study in Taiwan. An intravenous iron supplement of 100 mg/week was administered as an infusion in 100 ml of normal saline, until a total dose of 1000 mg was achieved. The primary outcome was evaluated by the changes in serum hematocrit (Hct levels. The changes in serum Hct and iron indices were evaluated every 2 weeks for 10 weeks. The results were collected from 21 April to 4 July 2013. Results: A total of 56 HD patients completed the study. Subjects were randomized into an iron sucrose group (26 patients and a ferric chloride group (30 patients. Between the two treatment groups, there were no statistically significant differences in the change in serum Hct, ferritin, iron, or total iron binding capacity (P > 0.05. In the iron sucrose group, the increase in Hct levels was statistically significant at weeks 4, 8, and 10. In the ferric chloride group, the increase in Hct levels was statistically significant at week 8. No obvious major side effects were observed in both groups. Conclusion: In the study subjects, parenteral iron sucrose was as effective and safe as ferric chloride for treating anemia in HD patients.

  12. Iron Homeostasis and Nutritional Iron Deficiency123

    OpenAIRE

    2011-01-01

    Nonheme food ferritin (FTN) iron minerals, nonheme iron complexes, and heme iron contribute to the balance between food iron absorption and body iron homeostasis. Iron absorption depends on membrane transporter proteins DMT1, PCP/HCP1, ferroportin (FPN), TRF2, and matriptase 2. Mutations in DMT1 and matriptase-2 cause iron deficiency; mutations in FPN, HFE, and TRF2 cause iron excess. Intracellular iron homeostasis depends on coordinated regulation of iron trafficking and storage proteins enc...

  13. Chemical Force Spectroscopy Evidence Supporting the Layer-by-Layer Model of Organic Matter Binding to Iron (oxy)Hydroxide Mineral Surfaces

    KAUST Repository

    Chassé, Alexander W.

    2015-08-18

    © 2015 American Chemical Society. The adsorption of dissolved organic matter (DOM) to metal (oxy)hydroxide mineral surfaces is a critical step for C sequestration in soils. Although equilibrium studies have described some of the factors controlling this process, the molecular-scale description of the adsorption process has been more limited. Chemical force spectroscopy revealed differing adhesion strengths of DOM extracted from three soils and a reference peat soil material to an iron (oxy)hydroxide mineral surface. The DOM was characterized using ultrahigh-resolution negative ion mode electrospray ionization Fourier Transform ion cyclotron resonance mass spectrometry. The results indicate that carboxyl-rich aromatic and N-containing aliphatic molecules of DOM are correlated with high adhesion forces. Increasing molecular mass was shown to decrease the adhesion force between the mineral surface and the DOM. Kendrick mass defect analysis suggests that mechanisms involving two carboxyl groups result in the most stable bond to the mineral surface. We conceptualize these results using a layer-by-layer "onion" model of organic matter stabilization on soil mineral surfaces.

  14. Chemical Force Spectroscopy Evidence Supporting the Layer-by-Layer Model of Organic Matter Binding to Iron (oxy)Hydroxide Mineral Surfaces.

    Science.gov (United States)

    Chassé, Alexander W; Ohno, Tsutomu; Higgins, Steven R; Amirbahman, Aria; Yildirim, Nadir; Parr, Thomas B

    2015-08-18

    The adsorption of dissolved organic matter (DOM) to metal (oxy)hydroxide mineral surfaces is a critical step for C sequestration in soils. Although equilibrium studies have described some of the factors controlling this process, the molecular-scale description of the adsorption process has been more limited. Chemical force spectroscopy revealed differing adhesion strengths of DOM extracted from three soils and a reference peat soil material to an iron (oxy)hydroxide mineral surface. The DOM was characterized using ultrahigh-resolution negative ion mode electrospray ionization Fourier Transform ion cyclotron resonance mass spectrometry. The results indicate that carboxyl-rich aromatic and N-containing aliphatic molecules of DOM are correlated with high adhesion forces. Increasing molecular mass was shown to decrease the adhesion force between the mineral surface and the DOM. Kendrick mass defect analysis suggests that mechanisms involving two carboxyl groups result in the most stable bond to the mineral surface. We conceptualize these results using a layer-by-layer "onion" model of organic matter stabilization on soil mineral surfaces.

  15. Iron Deficiency in Heart Failure: A Practical Guide

    OpenAIRE

    Nicole Ebner; Stephan von Haehling

    2013-01-01

    Iron is an element necessary for cells due to its capacity of transporting oxygen and electrons. One of the important co-morbidities in heart failure is iron deficiency. Iron has relevant biological functions, for example, the formation of haemoglobin, myoglobin and numerous enzymatic groups. The prevalence of iron deficiency increases with the severity of heart failure. For a long time, the influence of iron deficiency was underestimated especially in terms of worsening of cardiovascular dis...

  16. Chemically synthesized glycosides of hydroxylated flavylium ions as suitable models of anthocyanins: binding to iron ions and human serum albumin, antioxidant activity in model gastric conditions.

    Science.gov (United States)

    Al Bittar, Sheiraz; Mora, Nathalie; Loonis, Michèle; Dangles, Olivier

    2014-12-11

    Polyhydroxylated flavylium ions, such as 3',4',7-trihydroxyflavylium chloride (P1) and its more water-soluble 7-O-β-d-glucopyranoside (P2), are readily accessible by chemical synthesis and suitable models of natural anthocyanins in terms of color and species distribution in aqueous solution. Owing to their catechol B-ring, they rapidly bind FeIII, weakly interact with FeII and promote its autoxidation to FeIII. Both pigments inhibit heme-induced lipid peroxidation in mildly acidic conditions (a model of postprandial oxidative stress in the stomach), the colorless (chalcone) forms being more potent than the colored forms. Finally, P1 and P2 are moderate ligands of human serum albumin (HSA), their likely carrier in the blood circulation, with chalcones having a higher affinity for HSA than the corresponding colored forms.

  17. Chemically Synthesized Glycosides of Hydroxylated Flavylium Ions as Suitable Models of Anthocyanins: Binding to Iron Ions and Human Serum Albumin, Antioxidant Activity in Model Gastric Conditions

    Directory of Open Access Journals (Sweden)

    Sheiraz Al Bittar

    2014-12-01

    Full Text Available Polyhydroxylated flavylium ions, such as 3',4',7-trihydroxyflavylium chloride (P1 and its more water-soluble 7-O-β-d-glucopyranoside (P2, are readily accessible by chemical synthesis and suitable models of natural anthocyanins in terms of color and species distribution in aqueous solution. Owing to their catechol B-ring, they rapidly bind FeIII, weakly interact with FeII and promote its autoxidation to FeIII. Both pigments inhibit heme-induced lipid peroxidation in mildly acidic conditions (a model of postprandial oxidative stress in the stomach, the colorless (chalcone forms being more potent than the colored forms. Finally, P1 and P2 are moderate ligands of human serum albumin (HSA, their likely carrier in the blood circulation, with chalcones having a higher affinity for HSA than the corresponding colored forms.

  18. Dhatrilauha: Right choice for iron deficiency anemia in pregnancy.

    Science.gov (United States)

    Roy, Anuradha; Dwivedi, Manjari

    2014-01-01

    Anemia in pregnancy is multi-factorial. Iron deficiency anemia (IDA) is the most common one. Major cause is increased demand of iron during pregnancy. In Ayurveda, under Pandu-Roga the features of anemia are described. It is characterized by Vaivarnyata or Varnanasha (change/destruction in normal color of the body), a disorder of Pitta vitiation. Ayurvedic management is an effective way of curing anemia in general by a large number of Lauha preparations of which Dhatrilauha has been used widely for centuries. To evaluate the effect of Dhatrilauha in the management of IDA based on the scientific parameters among pregnant patients. A total of 58 cases were selected by simple randomized sampling method as per inclusion criteria of pregnant women between 4(th) and 7(th) months of pregnancy with a clinical diagnosis and laboratory confirmation of IDA. Dhatrilauha 500 mg in two divided doses after food with normal potable water were given for 45 days with three follow-ups, each of 15 days intervals. Final assessment was done after completion of 45 days and results were statistically analyzed by using Cochran's Q-test and Student's t-test. Dhatrilauha showed statistically significant (P intolerance, breathlessness, heartburn, pallor, constipation, hemoglobin, red blood cells (RBC), hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, RBC distribution width, mean platelet volume, serum iron, and total iron binding capacity. Dhatrilauha possesses many fold effectiveness in anemia (IDA), which was evidenced with the significant results obtained in the majority of parameters in this study.

  19. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente

    2012-01-01

    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive...... and ACC may increase the political focus on resources and environmental issues and may help to move local authorities towards a more holistic spatial planning approach. A carrying capacity approach could be an inspiration for local spatial planning in developing countries. A spatial planning act...... was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive carrying capacity (SCC) and assimilative...

  20. Iron Metabolism in Field Hockey Players During an Annual Training Cycle

    Directory of Open Access Journals (Sweden)

    Podgórski Tomasz

    2015-09-01

    Full Text Available Post-physical training changes in iron metabolism in the human body often occur. To fully describe these processes, fifteen male Polish National Team field hockey players (age 27.7 ± 5.2 years, body mass 72.8 ± 7.6 kg and body height 177.1 ± 5.7 cm were examined in three phases of an annual training cycle: preparatory (T1, competitive (T2 and transition (T3. To assess aerobic fitness, maximal oxygen uptake (VO2max was evaluated. Based on the iron concentration, the changes in total iron binding capacity (TIBC, unsaturated iron binding capacity (UIBC and other selected haematological indicators (haemoglobin, erythrocytes, mean corpuscular haemoglobin - MCH in iron metabolism were estimated. The average values of maximum oxygen uptake increased from 54.97 ± 3.62 ml·kg−1·min−1 in T1 to 59.93 ± 3.55 ml·kg−1·min−1 in T2 (p<0.05 and then decreased to 56.21 ± 4.56 ml·kg−1·min−1 in T3 (p<0.05. No statistically significant changes in the erythrocyte count were noted. The MCH and haemoglobin concentration decreased between T1 and T2. The maximal exercise test caused a significant (p<0.05 increase in the plasma iron concentration during the competition and transition phases. Progressive but non-significant increases in resting iron concentration, TIBC and UIBC in the analysed annual training cycle were noted. To show global changes in iron metabolism in the human body, it is necessary to determine additional variables, i.e. UIBC, TIBC, haemoglobin, MCH or the erythrocyte count. The direction of changes in iron metabolism depends on both the duration and intensity of the physical activity and the fitness level of the subjects. Dietary intake of iron increases the level of this trace element and prevents anaemia associated with training overloads.

  1. Oligomerization and DNA-binding capacity of Pmr, a histone-like protein H1 (H-NS) family protein encoded on IncP-7 carbazole-degradative plasmid pCAR1.

    Science.gov (United States)

    Suzuki, Chiho; Yun, Choong-Soo; Umeda, Takashi; Terabayashi, Tsuguno; Watanabe, Kazuya; Yamane, Hisakazu; Nojiri, Hideaki

    2011-01-01

    Pmr, a histone-like protein H1 (H-NS) family protein encoded on plasmid pCAR1, is a key factor in optimizing gene transcription on both pCAR1 and the host chromosome. To clarify the mode of function of Pmr, we performed gel filtration chromatography analysis and protein-protein cross-linking, and found that Pmr forms homo-oligomers, consisting of its homodimers. We also found, by atomic force microscopy, that Pmr has DNA-bridging capacity. From these results, Pmr was deduced to have features common to H-NS family proteins. Additionally, evaluating protein-DNA affinity is important to clarify the mode of function of Pmr, and hence we performed an electrophoretic mobility shift assay. Though Pmr formed high-order protein-DNA complexes and did not show preference for nucleic acid sequences, the C-terminal region of Pmr did, suggesting that the DNA-binding affinity of Pmr can be evaluated by using its C-terminal region.

  2. Alteration of iron homeostasis following chronic exposure to manganese in rats1

    Science.gov (United States)

    Zheng, Wei; Zhao, Qiuqu; Slavkovich, Vesna; Aschner, Michael; Graziano, Joseph H.

    2014-01-01

    Recent studies suggest that manganese-induced neurodegenerative toxicity may be partly due to its action on aconitase, which participates in cellular iron regulation and mitochondrial energy production. This study was performed to investigate whether chronic manganese exposure in rats influenced the homeostasis of iron in blood and cerebrospinal fluid (CSF). Groups of 8–10 rats received intraperitoneal injections of MnCl2 at the dose of 6 mg Mn/kg/day or equal volume of saline for 30 days. Concentrations of manganese and iron in plasma and CSF were determined by atomic absorption spectrophotometry. Rats exposed to manganese showed a greatly elevated manganese concentration in both plasma and CSF. The magnitude of increase in CSF manganese (11-fold) was equivalent to that of plasma (10-fold). Chronic manganese exposure resulted in a 32% decrease in plasma iron (p < 0.01) and no changes in plasma total iron binding capacity (TIBC). However, it increased CSF iron by 3-fold as compared to the controls (p < 0.01). Northern blot analyses of whole brain homogenates revealed a 34% increase in the expression of glutamine synthetase (p < 0.05) with unchanged metallothionein-I in manganese-intoxicated rats. When the cultured choroidal epithelial cells derived from rat choroid plexus were incubated with MnCl2 (100 µM) for four days, the expression of transferrin receptor mRNA appeared to exceed by 50% that of control (p < 0.002). The results indicate that chronic manganese exposure alters iron homeostasis possibly by expediting unidirectional influx of iron from the systemic circulation to cerebral compartment. The action appears likely to be mediated by manganese-facilitated iron transport at brain barrier systems. PMID:10375687

  3. Photochemistry of iron(III)-carboxylato complexes in aqueous atmospheric particles

    Science.gov (United States)

    Weller, Christian; Herrmann, Hartmut

    2010-05-01

    Iron is always present in the atmosphere in concentrations from ~10-9 M (clouds, rain) up to ~10-3 M (fog, particles). Sources are mainly mineral dust emissions. Iron complexes are very good absorbers in the UV-VIS actinic region and therefore photo-chemically reactive. Iron complex photolysis leads to radical production and can initiate radical chain reactions, which is related to the oxidizing capacity of the atmosphere. These radical chain reactions are involved in the decomposition and transformation of a variety of chemical compounds in cloud droplets and deliquescent particles. Additionally, the photochemical reaction itself can be a degradation pathway for organic compounds with the ability to bind iron. Iron-complexes of atmospherically relevant coordination compounds like oxalate, malonate, succinate, glutarate, tartronate, gluconate, pyruvate and glyoxalate have been investigated in laboratory experiments. Iron speciation depends on the iron-ligand ratio and the pH. The most suitable experimental conditions were calculated with a speciation program (Visual Minteq). The solutions were prepared accordingly and transferred to a 1 cm quartz cuvette and flash-photolyzed with an excimer laser at wavelengths 308 or 351 nm. Photochemically produced Fe2+ has been measured by spectrometry at 510 nm as Fe(phenantroline)32+. Fe2+ overall effective quantum yields have been calculated with the concentration of photochemically produced Fe2+ and the measured energy of the excimer laser pulse. The laser pulse energy was measured with a pyroelectric sensor. For some iron-carboxylate systems the experimental parameters like the oxygen content of the solution, the initial iron concentration and the incident laser energy were systematically altered to observe an effect on the overall quantum yield. The dependence of some quantum yields on these parameters allows in some cases an interpretation of the underlying photochemical reaction mechanism. Quantum yields of malonate

  4. Differences in the Responses to Iron Deficiency Stress between Bean and Maize

    OpenAIRE

    米谷, 力; 森次, 益三; 河﨑, 利夫

    1995-01-01

    The responses to iron deficiency stress in bean and maize were compared. The susceptibility to iron deficiency stress was smaller in bean than in maize;i.e., the tolerance to iron deficiency was greater in bean than in maize. The roots of the bean plants exposed to iron deficiency stress, developed iron reducing capacity and medium-pH lowering capacity,but not the roots of maize. The iron reducing capacity and medium-pH lowering capacity of the bean roots were inhibited by a shadowing, detopp...

  5. Characterization of superparamagnetic iron oxide nanoparticles and its application in protein purification.

    Science.gov (United States)

    Okoli, Chuka; Fornara, Andrea; Qin, Jian; Toprak, Muhammet S; Dalhammar, Gunnel; Muhammed, Mamoun; Rajarao, Gunaratna K

    2011-11-01

    The application of surface modified magnetic adsorbent particles in combination with magnetic separation techniques has received considerable awareness in recent years. There is a particular need in protein purification and analysis for specific, functional and generic methods of protein binding on solid supports. Nanoscale superparamagnetic iron oxide particles have been used to purify a natural coagulant protein extracted from Moringa oleifera seeds. Spectrophotometric analysis of the coagulant protein was performed using synthetic clay solution as substrate. Protein binding with carboxyl and silica surface modified superparamagnetic iron oxide nanoparticles (SPION) were compared with the known carboxyl methyl cellulose (CMC) beads of approximately 1 microm. SPION modified with carboxyl surface showed higher binding capacity towards the coagulant protein compared to the CMC beads. The high surface area to volume ratio of the carboxyl-coated SPION resulted in high binding capacity and rapid adsorption kinetics of the crude protein extract. The purification and molecular weight of coagulant protein is analyzed by SDS-PAGE. This approach utilizes the most efficient, feasible and economical method of coagulant protein purification and it can also be applicable to other proteins that possess similar properties.

  6. Accelerated dissolution of iron oxides in ice

    Directory of Open Access Journals (Sweden)

    D. Jeong

    2012-08-01

    Full Text Available Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a~new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4, the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the type of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid-like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from −10 °C to −196 °C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

  7. Accelerated dissolution of iron oxides in ice

    Directory of Open Access Journals (Sweden)

    D. Jeong

    2012-11-01

    Full Text Available Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4, the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the surface area of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from −10 to −196 °C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

  8. 化脓链球菌中铁结合蛋白MtsA二级结构的研究%The Secondery Structure Study of Iron-binding Protein MtsA from Streptococcus pyogenes

    Institute of Scientific and Technical Information of China (English)

    王红翠; 张静; 徐倩; 许丽娜; 王南杰; 孙雪松

    2012-01-01

    化脓性链球菌是一种革兰氏阳性人类致病菌,其生长和感染离不开铁离子.MtsA是化脓链球菌中直接结合铁离子的一个脂蛋白.通过PCR扩增化脓性链球菌MGAS5005中的MtsA基因,构建高效表达质粒pGEX-MtsA,将其转化到大肠杆菌BL21中并用IPTG进行诱导表达.利用亲和层析方法纯化表达产物.通过多序列比对分析了MtsA铁结合中心的保守性,利用定点突变技术将MtsA的结合配体单位点及多位点进行突变,结合圆二色谱分析这些氨基酸突变后蛋白二级结构的变化.多序列比对结果表明MtsA结合铁离子的氨基酸位点是保守的,4个关键氨基酸位点处于蛋白空间的凹陷处.通过比较空载及饱和铁离子的野生型蛋白以及突变体蛋白的圆二色吸收光谱,发现野生型MtsA结合铁离子后结构更加紧密,H68A,E206A和D281A则比野生型的二级结构松散,而H140A的二级结构和野生型的几乎没有差别.对MtsA 4个结合配体突变后其二级结构变化的研究,为进一步研究细菌中的铁转运机理及开发疫苗候选药物和药靶奠定了一定的理论依据.%Streptococcus pyogenes is a Gram-positive human pathogen, and iron is essential for its survival and infection. MtsA is a lipoprotein of Streptococcus pyogenes, which is responsible for iron binding. MtsA was amplified by PCR from Streptococcus pyogenes MGAS5005 and constructed the recombinant plasmid pGEX-MtsA. The recombinant plasmid was transformed into Escherichia coli BL21 to express the fusion protein after induction with IPTG. The protein was purified using affinity chromatography. The conservative of the MtsA iron binding center was analyzed using multiple alignment. The mutant proteins were constructed by site-directed mutagenesis. Circular dichroism was used to collect the changes of mutants' secondery structure when compared to wild-type protein. The result of multiple alignment showed the four binding amino acids were

  9. Iron load

    Directory of Open Access Journals (Sweden)

    Filippo Cassarà

    2013-03-01

    Full Text Available Recent research addressed the main role of hepcidin in the regulation of iron metabolism. However, while this mechanism could be relevant in causing iron load in Thalassemia Intermedia and Sickle-Cell Anemia, its role in Thalassemia Major (TM is marginal. This is mainly due to the high impact of transfusional requirement into the severe increase of body iron. Moreover, the damage of iron load may be worsened by infections, as HCV hepatitis, or liver and endocrinological damage. One of the most relevant associations was found between splenectomy and increase of risk for mortality due,probably, to more severe iron load. These issues suggest as morbidity and mortality of this group of patients they do not depend only by our ability in controlling heart damage but even in preventing or treating particular infections and complications. This finding is supported by the impairment of survival curves in patients with complications different from heart damage. However, because, during recent years different direct and indirect methods to detect iron overload in patients affected by secondary hemochromatosis have been implemented, our ability to maintain under control iron load is significantly improved. Anyway, the future in iron load management remains to be able to have an iron load map of our body for targeting chelation and other medical treatment according to the single organ damage.

  10. Yap5 is an iron-responsive transcriptional activator that regulates vacuolar iron storage in yeast.

    Science.gov (United States)

    Li, Liangtao; Bagley, Dustin; Ward, Diane M; Kaplan, Jerry

    2008-02-01

    The transporter Ccc1 imports iron into the vacuole, which is the major site of iron storage in fungi and plants. CCC1 mRNA is destabilized under low-iron conditions by the binding of Cth1 and Cth2 to the 3' untranslated region (S. Puig, E. Askeland, and D. J. Thiele, Cell 120:99-110, 2005). Here, we show that the transcription of CCC1 is stimulated by iron through a Yap consensus site in the CCC1 promoter. We identified YAP5 as being the iron-sensitive transcription factor and show that a yap5Delta strain is sensitive to high iron. Green fluorescent protein-tagged Yap5 is localized to the nucleus and occupies the CCC1 promoter independent of the iron concentration. Yap5 contains two cysteine-rich domains, and the mutation of the cysteines to alanines in each of the domains affects the transcription of CCC1 but not DNA binding. The fusion of the Yap5 cysteine-containing domains to a GAL4 DNA binding domain results in iron-sensitive GAL1-lacZ expression. Iron affects the sulfhydryl status of Yap5, which is indicative of the generation of intramolecular disulfide bonds. These results show that Yap5 is an iron-sensing transcription factor and that iron regulates transcriptional activation.

  11. Yap5 Is an Iron-Responsive Transcriptional Activator That Regulates Vacuolar Iron Storage in Yeast▿

    Science.gov (United States)

    Li, Liangtao; Bagley, Dustin; Ward, Diane M.; Kaplan, Jerry

    2008-01-01

    The transporter Ccc1 imports iron into the vacuole, which is the major site of iron storage in fungi and plants. CCC1 mRNA is destabilized under low-iron conditions by the binding of Cth1 and Cth2 to the 3′ untranslated region (S. Puig, E. Askeland, and D. J. Thiele, Cell 120:99-110, 2005). Here, we show that the transcription of CCC1 is stimulated by iron through a Yap consensus site in the CCC1 promoter. We identified YAP5 as being the iron-sensitive transcription factor and show that a yap5Δ strain is sensitive to high iron. Green fluorescent protein-tagged Yap5 is localized to the nucleus and occupies the CCC1 promoter independent of the iron concentration. Yap5 contains two cysteine-rich domains, and the mutation of the cysteines to alanines in each of the domains affects the transcription of CCC1 but not DNA binding. The fusion of the Yap5 cysteine-containing domains to a GAL4 DNA binding domain results in iron-sensitive GAL1-lacZ expression. Iron affects the sulfhydryl status of Yap5, which is indicative of the generation of intramolecular disulfide bonds. These results show that Yap5 is an iron-sensing transcription factor and that iron regulates transcriptional activation. PMID:18070921

  12. INCREASING AND DECREASING PHASES OF FERRITIN AND HEMOSIDERIN IRON DETERMINED BY SERUM FERRITIN KINETICS

    Science.gov (United States)

    SAITO, HIROSHI; HAYASHI, HISAO; TOMITA, AKIHIRO; OHASHI, HARUHIKO; MAEDA, HIDEAKI; NAOE, TOMOKI

    2013-01-01

    ABSTRACT We attempted to clarify the mechanism of the storage iron metabolism. A new program of serum ferritin kinetics was applied for studying the increasing and decreasing phases of ferritin and hemosiderin iron in iron addition and removal in patients with a normal level of iron stores or iron overload. The change of ferritin iron in response to iron addition and removal was rapid in the initial stage, but it was slow later. In contrast, the change of hemosiderin iron was slow in the initial stage, but it became rapid later. These changes of ferritin and hemosiderin iron suggest that the turnover of ferritin iron is preferential to that of hemosiderin iron, and that the initially existed ferritin iron is gradually replaced by the ferritin iron recovered by taking iron from hemosiderin in iron mobilization. The crossing of the increasing curves of ferritin and hemosiderin iron in iron addition indicates a switching of the principal storage iron from ferritin to hemosiderin. The crossing point shifted toward a higher storage iron level in the increase of iron deposition. Iron storing capacity can be increased not only by the transformation of ferritin into hemosiderin, but also by the expansion of cell space as seen by hepatomegaly in hereditary hemochromatosis. The amounts of hemosiderin iron exceeded ferritin iron in all 10 patients with chronic hepatitis C even though they had normal storage iron levels. This suggests it is difficult to store iron in the form of ferritin in chronic hepatitis C. PMID:24640177

  13. Iron refractory iron deficiency anemia

    OpenAIRE

    De Falco, Luigia; Sanchez, Mayka; Silvestri, Laura; Kannengiesser, Caroline; Muckenthaler, Martina U; Iolascon, Achille; Gouya, Laurent; Camaschella, Clara; Beaumont, Carole

    2013-01-01

    Iron refractory iron deficiency anemia is a hereditary recessive anemia due to a defect in the TMPRSS6 gene encoding Matriptase-2. This protein is a transmembrane serine protease that plays an essential role in down-regulating hepcidin, the key regulator of iron homeostasis. Hallmarks of this disease are microcytic hypochromic anemia, low transferrin saturation and normal/high serum hepcidin values. The anemia appears in the post-natal period, although in some cases it is only diagnosed in ad...

  14. 2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes BHV-1 infection in mammalian cells by interfering with iron homeostasis regulation.

    Directory of Open Access Journals (Sweden)

    Filomena Fiorito

    Full Text Available Mammalian cells require iron to satisfy metabolic needs or to accomplish specialized functions, and DNA viruses, like bovine herpesvirus 1 (BHV-1, require an iron-replete host to efficiently replicate, so that iron bioavailability is an important component of viral virulence. Cellular iron metabolism is coordinately controlled by the Iron Regulatory Proteins (IRP1 and IRP2, whose activity is affected by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, a current and persistent environmental contaminant. Considering that TCDD enhances BHV-1 replication, herein we analyzed the effects of TCDD on iron metabolism during BHV-1 infection in MDBK cells, and presented evidences of a divergent modulation of IRP1 and IRP2 RNA-binding capacity. Moreover, an up-regulation of transferrin receptor 1 (TfR1 and a concomitant down-regulation of ferritin were observed. This scenario led to an expansion of the labile iron pool (LIP and induces a significant enhance of viral titer, as confirmed by increased levels of BHV-1 infected cell protein 0 (bICP0, the major transcriptional regulatory protein of BHV-1. Taken together, our data suggest that TCDD increases the free intracellular iron availability thereby promoting the onset of BHV-1 infection and rendering bovine cells more vulnerable to the virus.

  15. The effect of digestive enzymes on the binding and bacteriostatic properties of lactoferrin and vitamin B12 binder in human milk.

    Science.gov (United States)

    Samson, R R; Mirtle, C; McClelland, D B

    1980-07-01

    Human milk contains unsaturated lactoferrin and vitamin B12 binding protein. It has been suggested that these proteins may exert antibacterial effects in the intestine of the breast fed infant, but the effect of the intestinal environment on the antibacterial effect of these proteins has not been described. In this study human milk was treated with pepsin and trypsin and the influence of digestion on iron and vitamin B12 binding capacity, bacterial uptake of iron and vitamin B12 from milk and bacteriostatic effect was studied. Pepsin digestion had no effect on vitamin B12 binding capacity, or the ability of bacteria to take up vitamin B12, or the growth inhibitory effect on a vitamin B12 dependent strain. In contrast, trypsin digestion did not affect iron binding or bacteriostatic effects attributable to lactoferrin. The. findings support an in vivo bacteriostatic role for lactoferrin in the breast fed neonate's intestine but do not support a similar role for the vitamin B12 binding protein.

  16. The prevalence of anemia and iron deficiency is more common in breastfed infants than their mothers in Bhaktapur, Nepal

    Science.gov (United States)

    Chandyo, R K; Henjum, S; Ulak, M; Thorne- Lyman, A L; Ulvik, R J; Shrestha, P S; Locks, L; Fawzi, W; Strand, T A

    2016-01-01

    Background/Objectives: Iron deficiency anemia is a widespread public health problem, particularly in low- and middle-income countries. Maternal iron status around and during pregnancy may influence infant iron status. We examined multiple biomarkers to determine the prevalence of iron deficiency and anemia among breastfed infants and explored its relationship with maternal and infant characteristics in Bhaktapur, Nepal. Subjects/Methods: In a cross-sectional survey, we randomly selected 500 mother–infant pairs from Bhaktapur municipality. Blood was analyzed for hemoglobin, ferritin, total iron-binding capacity, transferrin receptors and C-reactive protein. Results: The altitude-adjusted prevalence of anemia was 49% among infants 2–6-month-old (hemaglobin (Hb) <10.8 g/dl) and 72% among infants 7–12-month-old (Hb <11.3 g/dl). Iron deficiency anemia, defined as anemia and serum ferritin <20 or <12 μg/l, affected 9 and 26% of infants of these same age groups. Twenty percent of mothers had anemia (Hb <12.3 g/dl), but only one-fifth was explained by depletion of iron stores. Significant predictors of infant iron status and anemia were infant age, sex and duration of exclusive breastfeeding and maternal ferritin concentrations. Conclusions: Our findings suggest that iron supplementation in pregnancy is likely to have resulted in a low prevalence of postpartum anemia. The higher prevalence of anemia and iron deficiency among breastfed infants compared with their mothers suggests calls for intervention targeting newborns and infants. PMID:26626049

  17. THE IMPACT OF IRON DEFICIENCY ON HBA2 LEVEL IN BETA THALASSEMIA MINOR IN SULAIMANI NORTHEASTERN IRAQ

    Directory of Open Access Journals (Sweden)

    Awaz Ahmed Kamal

    2015-11-01

    Full Text Available Background: HbA2 plays a key role in screening programs for beta thalassemia because a small increase in this fraction is the most important marker of beta thalassemia heterozygous carriers. The potential impact of coincident iron deficiency on HbA2 based identification of beta thalassemia minor is worrisome issue for screening laboratories, this is especially true for resource-constrained settings where iron deficiency is wide spread and molecular confirmatory tests for borderline HbA2 values may be unavailable. Objective: the aim of this study is to evaluate the effect of iron deficiency on HbA2 level in order to improve the detection of beta thalassemia trait with or without iron deficiency in our population. Materials and Method: In this study 145 individuals were enrolled including normal controls (50, beta thalassemia minor (50 and coincident beta thalassemia with iron deficiency cases (45. Complete blood count, serum iron, total iron binding capacity and HbA2 with HbF estimation were done for every individual. Result: The mean HbA2 level was (2.4± 0.4 in control, (5.2 ± 0.9 in beta thalassemia minor and 5.1± 0.9 in coincident iron deficiency with beta thalassemia minors. All hematological parameters were significantly lower in beta thalassemia minor and coincident iron deficiency with beta thalassemia minor in comparison to the control group .Mean HbA2 level did not show a significant difference in thalassemia minor (5.2±0.9 when compared with the mean HbA2 levels in coincidentiron deficiency with beta thalassemia minor. Conclusion: The presence of iron deficiency did not preclude the detection of beta thalassemia minor in our population

  18. Post-synaptic density-95 (PSD-95) binding capacity of G-protein-coupled receptor 30 (GPR30), an estrogen receptor that can be identified in hippocampal dendritic spines.

    Science.gov (United States)

    Akama, Keith T; Thompson, Louisa I; Milner, Teresa A; McEwen, Bruce S

    2013-03-01

    The estrogen 17β-estradiol (E2) modulates dendritic spine plasticity in the cornu ammonis 1 (CA1) region of the hippocampus, and GPR30 (G-protein coupled estrogen receptor 1 (GPER1)) is an estrogen-sensitive G-protein-coupled receptor (GPCR) that is expressed in the mammalian brain and in specific subregions that are responsive to E2, including the hippocampus. The subcellular localization of hippocampal GPR30, however, remains unclear. Here, we demonstrate that GPR30 immunoreactivity is detected in dendritic spines of rat CA1 hippocampal neurons in vivo and that GPR30 protein can be found in rat brain synaptosomes. GPR30 immunoreactivity is identified at the post-synaptic density (PSD) and in the adjacent peri-synaptic zone, and GPR30 can associate with the spine scaffolding protein PSD-95 both in vitro and in vivo. This PSD-95 binding capacity of GPR30 is specific and determined by the receptor C-terminal tail that is both necessary and sufficient for PSD-95 interaction. The interaction with PSD-95 functions to increase GPR30 protein levels residing at the plasma membrane surface. GPR30 associates with the N-terminal tandem pair of PDZ domains in PSD-95, suggesting that PSD-95 may be involved in clustering GPR30 with other receptors in the hippocampus. We demonstrate that GPR30 has the potential to associate with additional post-synaptic GPCRs, including the membrane progestin receptor, the corticotropin releasing hormone receptor, and the 5HT1a serotonin receptor. These data demonstrate that GPR30 is well positioned in the dendritic spine compartment to integrate E2 sensitivity directly onto multiple inputs on synaptic activity and might begin to provide a molecular explanation as to how E2 modulates dendritic spine plasticity.

  19. Post-synaptic Density-95 (PSD-95) Binding Capacity of G-protein-coupled Receptor 30 (GPR30), an Estrogen Receptor That Can Be Identified in Hippocampal Dendritic Spines*

    Science.gov (United States)

    Akama, Keith T.; Thompson, Louisa I.; Milner, Teresa A.; McEwen, Bruce S.

    2013-01-01

    The estrogen 17β-estradiol (E2) modulates dendritic spine plasticity in the cornu ammonis 1 (CA1) region of the hippocampus, and GPR30 (G-protein coupled estrogen receptor 1 (GPER1)) is an estrogen-sensitive G-protein-coupled receptor (GPCR) that is expressed in the mammalian brain and in specific subregions that are responsive to E2, including the hippocampus. The subcellular localization of hippocampal GPR30, however, remains unclear. Here, we demonstrate that GPR30 immunoreactivity is detected in dendritic spines of rat CA1 hippocampal neurons in vivo and that GPR30 protein can be found in rat brain synaptosomes. GPR30 immunoreactivity is identified at the post-synaptic density (PSD) and in the adjacent peri-synaptic zone, and GPR30 can associate with the spine scaffolding protein PSD-95 both in vitro and in vivo. This PSD-95 binding capacity of GPR30 is specific and determined by the receptor C-terminal tail that is both necessary and sufficient for PSD-95 interaction. The interaction with PSD-95 functions to increase GPR30 protein levels residing at the plasma membrane surface. GPR30 associates with the N-terminal tandem pair of PDZ domains in PSD-95, suggesting that PSD-95 may be involved in clustering GPR30 with other receptors in the hippocampus. We demonstrate that GPR30 has the potential to associate with additional post-synaptic GPCRs, including the membrane progestin receptor, the corticotropin releasing hormone receptor, and the 5HT1a serotonin receptor. These data demonstrate that GPR30 is well positioned in the dendritic spine compartment to integrate E2 sensitivity directly onto multiple inputs on synaptic activity and might begin to provide a molecular explanation as to how E2 modulates dendritic spine plasticity. PMID:23300088

  20. Cast irons

    CERN Document Server

    1996-01-01

    Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

  1. Iron bioaccumulation in mycelium of Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Sandra M. Almeida

    2015-03-01

    Full Text Available Pleurotus ostreatus is able to bioaccumulate several metals in its cell structures; however, there are no reports on its capacity to bioaccumulate iron. The objective of this study was to evaluate cultivation variables to increase iron bioaccumulation in P. ostreatusmycelium. A full factorial design and a central composite design were utilized to evaluate the effect of the following variables: nitrogen and carbon sources, pH and iron concentration in the solid culture medium to produce iron bioaccumulated in mycelial biomass. The maximum production of P. ostreatus mycelial biomass was obtained with yeast extract at 2.96 g of nitrogen L−1 and glucose at 28.45 g L−1. The most important variable to bioaccumulation was the iron concentration in the cultivation medium. Iron concentration at 175 mg L−1 or higher in the culture medium strongly inhibits the mycelial growth. The highest iron concentration in the mycelium was 3500 mg kg−1 produced with iron addition of 300 mg L−1. The highest iron bioaccumulation in the mycelium was obtained in culture medium with 150 mg L−1 of iron. Iron bioaccumulation in P. ostreatus mycelium is a potential alternative to produce non-animal food sources of iron.

  2. Iron bioaccumulation in mycelium of Pleurotus ostreatus.

    Science.gov (United States)

    Almeida, Sandra M; Umeo, Suzana H; Marcante, Rafael C; Yokota, Meire E; Valle, Juliana S; Dragunski, Douglas C; Colauto, Nelson B; Linde, Giani A

    2015-03-01

    Pleurotus ostreatus is able to bioaccumulate several metals in its cell structures; however, there are no reports on its capacity to bioaccumulate iron. The objective of this study was to evaluate cultivation variables to increase iron bioaccumulation in P. ostreatus mycelium. A full factorial design and a central composite design were utilized to evaluate the effect of the following variables: nitrogen and carbon sources, pH and iron concentration in the solid culture medium to produce iron bioaccumulated in mycelial biomass. The maximum production of P. ostreatus mycelial biomass was obtained with yeast extract at 2.96 g of nitrogen L (-1) and glucose at 28.45 g L (-1) . The most important variable to bioaccumulation was the iron concentration in the cultivation medium. Iron concentration at 175 mg L (-1) or higher in the culture medium strongly inhibits the mycelial growth. The highest iron concentration in the mycelium was 3500 mg kg (-1) produced with iron addition of 300 mg L (-1) . The highest iron bioaccumulation in the mycelium was obtained in culture medium with 150 mg L (-1) of iron. Iron bioaccumulation in P. ostreatus mycelium is a potential alternative to produce non-animal food sources of iron.

  3. Ferritin Is a Marker of Inflammation rather than Iron Deficiency in Overweight and Obese People

    Directory of Open Access Journals (Sweden)

    Abidullah Khan

    2016-01-01

    Full Text Available Background. In clinical practice, serum ferritin is used as a screening tool to detect iron deficiency. However, its reliability in obesity has been questioned. Objectives. To investigate the role of ferritin in overweight and obese people, either as a marker of inflammation or iron deficiency. Methods. On the basis of body mass index (BMI, 150 participants were divided into three equal groups: A: BMI 18.5–25 kg/m2, B: BMI 25–30 kg/m2, and C: BMI>30 kg/m2. Serum iron, total iron binding capacity (TIBC, transferrin saturation, ferritin, C-reactive protein, and hemoglobin (Hb were measured for each participant and analyzed through SPSS version 16. One-way ANOVA and Pearson’s correlation tests were applied. Results. Ferritin was the highest in group C (M=163.48±2.23, P<0.001 and the lowest in group A, (M=152.78±1.81, P<0.001. Contrarily to ferritin, transferrin was the lowest in group C, (M=30.65±1.39, P<0.001 and the highest in group A, (M=38.66±2.14, P<0.001. Ferritin had a strong positive correlation with both BMI (r=0.86, P<0.001 and CRP (r=0.87, P<0.001 and strong negative correlation with Hb, iron, TIBC, and transferrin saturation (P<0.001. Conclusion. Ferritin is a marker of inflammation rather than iron status in overweight and obese people. Complete iron profile including transferrin, rather than serum ferritin alone, can truly predict iron deficiency in such people.

  4. Helicobacter pylori-associated hypochlorhydria in children, and development of iron deficiency.

    Science.gov (United States)

    Harris, Paul R; Serrano, Carolina A; Villagrán, Andrea; Walker, Marjorie M; Thomson, Melanie; Duarte, Ignacio; Windle, Henry J; Crabtree, Jean E

    2013-04-01

    Acute Helicobacter pylori infection is associated with transient hypochlorhydria. In H pylori-associated atrophy, hypochlorhydria has a role in iron deficiency (ID) through changes in the physiology of iron-complex absorption. The aims were to evaluate the association between H pylori-associated hypochlorhydria and ID in children. Symptomatic children (n=123) were prospectively enrolled. Blood, gastric juice and gastric biopsies were taken, respectively, for haematological analyses, pH assessment and H pylori determination, and duodenal biopsies for exclusion of coeliac disease. Stool samples were collected for parasitology/microbiology. Thirteen children were excluded following parasitology and duodenal histopathology, and five due to impaired blood analysis. Ten children were hypochlorhydric (pH>4) and 33 were H pylori positive. In H pylori-positive children with pH>4 (n=6) serum iron and transferrin saturation levels % were significantly lower (pchildren with pH≤4. No differences in ferritin, or total iron binding capacity, were observed. In H pylori-negative children with pH>4, iron and transferrin saturation were not significantly different from children with pH≤4. Low serum iron and transferrin in childhood H pylori infection is associated with hypochlorhydria. In uninfected children, hypochlorhydria was not associated with altered serum iron parameters, indicating a combination of H pylori infection and/or inflammation, and hypochlorhydria has a role in the aetiology of ID. Although H pylori-associated hypochlorhydria is transient during acute gastritis, this alters iron homeostasis with clinical impact in developing countries with a high H pylori prevalence.

  5. Body iron status and gastric cancer risk in the EURGAST study.

    Science.gov (United States)

    Fonseca-Nunes, Ana; Agudo, Antonio; Aranda, Núria; Arija, Victoria; Cross, Amanda J; Molina, Esther; Sanchez, Maria Jose; Bueno-de-Mesquita, H B As; Siersema, Peter; Weiderpass, Elisabete; Krogh, Vittorio; Mattiello, Amalia; Tumino, Rosario; Saieva, Calogero; Naccarati, Alessio; Ohlsson, Bodil; Sjöberg, Klas; Boutron-Ruault, Marie-Christine; Cadeau, Claire; Fagherazzi, Guy; Boeing, Heiner; Steffen, Annika; Kühn, Tilman; Katzke, Verena; Tjønneland, Anne; Olsen, Anja; Khaw, Kay-Tee; Wareham, Nick; Key, Tim; Lu, Yunxia; Riboli, Elio; Peeters, Petra H; Gavrila, Diana; Dorronsoro, Miren; Quirós, José Ramón; Barricarte, Aurelio; Jenab, Mazda; Zamora-Ros, Raúl; Freisling, Heinz; Trichopoulou, Antonia; Lagiou, Pagona; Bamia, Christina; Jakszyn, Paula

    2015-12-15

    Although it appears biologically plausible for iron to be associated with gastric carcinogenesis, the evidence is insufficient to lead to any conclusions. To further investigate the relationship between body iron status and gastric cancer risk, we conducted a nested case-control study in the multicentric European Prospective Investigation into Cancer and Nutrition (EPIC) study. The study included 456 primary incident gastric adenocarcinoma cases and 900 matched controls that occurred during an average of 11 years of follow-up. We measured prediagnostic serum iron, ferritin, transferrin and C-reactive protein, and further estimated total iron-binding capacity (TIBC) and transferrin saturation (TS). Odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of gastric cancer by iron metrics were estimated from multivariable conditional logistic regression models. After adjusting for relevant confounders, we observed a statistically significant inverse association between gastric cancer and ferritin and TS indices (ORlog2  = 0.80, 95% CI = 0.72-0.88; OR10%increment  = 0.87, 95% CI = 0.78-0.97, respectively). These associations appear to be restricted to noncardia gastric cancer (ferritin showed a p for heterogeneity = 0.04 and TS had a p for heterogeneity = 0.02), and no differences were found by histological type. TIBC increased risk of overall gastric cancer (OR50 µg/dl  = 1.13, 95% CI = 1.02-1.2) and also with noncardia gastric cancer (p for heterogeneity = 0.04). Additional analysis suggests that time between blood draw and gastric cancer diagnosis could modify these findings. In conclusion, our results showed a decreased risk of gastric cancer related to higher body iron stores as measured by serum iron and ferritin. Further investigation is needed to clarify the role of iron in gastric carcinogenesis.

  6. Significance of assess the iron reserves of severe renal anemia patients before and after blood transfusion

    Institute of Scientific and Technical Information of China (English)

    Gui-Fen Zhang

    2015-01-01

    Objective:To study the significance of evaluating hemoglobin and iron reserves in the severe renal anemia patient before and after blood transfusion, to guide clinical treatment.Methods:Simple randomly selected 120 patients in phase 5 of chronic renal failure from the department of nephrology, who are regular dialysis with severe renal anemia, according to the situation of iron reserves before blood transfusion, patients will be divided into its reserves of iron deficiency and iron overload group and normal group, and the three groups were divided into 1 U and 2 U group. Comparing the change of different unit quantity of hemoglobin, serum iron, iron, protein and total iron binding force before and after blood transfusion and variation is compared between groups.Results: Three groups of patients with 1U blood transfusion ,Hemoglobin, serum iron and ferritin, total iron binding force, transferrin saturation are higher before a blood transfusion,The differences were statistically significant; before and after blood transfusion hemoglobin, serum iron and ferritin, total iron binding force, transferrin saturation change in 1 U group normal iron reserves compared with Insufficient iron reserves 1 U group has no statistically significant difference, iron overload 1 U group before and after blood transfusion hemoglobin, serum iron and ferritin, total iron binding force, transferrin saturation change significantly greater than Insufficient iron reserves 1 U group and 1U with normal iron reserves group, the differences were statistically significant; Three groups of patients blood transfusion after 2 U, hemoglobin, serum iron and ferritin, total iron binding force, transferrin saturation were higher before a blood transfusion, differences were statistically significant; iron overload 2 U group before and after blood transfusion hemoglobin, serum iron and ferritin, total iron binding force, transferrin saturation change significantly greater than Insufficient iron reserves 2

  7. Iron metabolism in BeWo chorion carcinoma cells. Transferrin-mediated uptake and release of iron.

    Science.gov (United States)

    van der Ende, A; du Maine, A; Simmons, C F; Schwartz, A L; Strous, G J

    1987-06-25

    Growing human choriocarcinoma BeWo b24 cells contain 1.5 X 10(6) functional cell surface transferrin binding sites and 2.0 X 10(6) intracellular binding sites. These cells rapidly accumulate iron at a rate of 360,000 iron atoms/min/cell. During iron uptake the transferrin and its receptor recycle at least each 19 min. The accumulated iron is released from the BeWo cells at a considerable rate. The time required to release 50% of previously accumulated iron into the extracellular medium is 30 h. This release process is cell line-specific as HeLa cells release very little if any iron. The release of iron by BeWo cells is stimulated by exogenous chelators such as apotransferrin, diethylenetriaminepenta-acetic acid, desferral, and apolactoferrin. The time required to release 50% of the previously accumulated iron into medium supplemented with chelator is 15 h. In the absence of added chelators iron is released as a low molecular weight complex, whereas in the presence of chelator the iron is found complexed to the chelator. Uptake of iron is inhibited by 250 microM primaquine or 2.5 microM monensin. However, the release of iron is not inhibited by these drugs. Intracellular iron is stored bound to ferritin. A model for the release of iron by BeWo cells and its implication for transplacental iron transport is discussed.

  8. Molecular Evolution of the Oxygen-Binding Hemerythrin Domain.

    Directory of Open Access Journals (Sweden)

    Claudia Alvarez-Carreño

    Full Text Available The evolution of oxygenic photosynthesis during Precambrian times entailed the diversification of strategies minimizing reactive oxygen species-associated damage. Four families of oxygen-carrier proteins (hemoglobin, hemerythrin and the two non-homologous families of arthropodan and molluscan hemocyanins are known to have evolved independently the capacity to bind oxygen reversibly, providing cells with strategies to cope with the evolutionary pressure of oxygen accumulation. Oxygen-binding hemerythrin was first studied in marine invertebrates but further research has made it clear that it is present in the three domains of life, strongly suggesting that its origin predated the emergence of eukaryotes.Oxygen-binding hemerythrins are a monophyletic sub-group of the hemerythrin/HHE (histidine, histidine, glutamic acid cation-binding domain. Oxygen-binding hemerythrin homologs were unambiguously identified in 367/2236 bacterial, 21/150 archaeal and 4/135 eukaryotic genomes. Overall, oxygen-binding hemerythrin homologues were found in the same proportion as single-domain and as long protein sequences. The associated functions of protein domains in long hemerythrin sequences can be classified in three major groups: signal transduction, phosphorelay response regulation, and protein binding. This suggests that in many organisms the reversible oxygen-binding capacity was incorporated in signaling pathways. A maximum-likelihood tree of oxygen-binding hemerythrin homologues revealed a complex evolutionary history in which lateral gene transfer, duplications and gene losses appear to have played an important role.Hemerythrin is an ancient protein domain with a complex evolutionary history. The distinctive iron-binding coordination site of oxygen-binding hemerythrins evolved first in prokaryotes, very likely prior to the divergence of Firmicutes and Proteobacteria, and spread into many bacterial, archaeal and eukaryotic species. The later evolution of the

  9. The role of ceruloplasmin in iron metabolism.

    Science.gov (United States)

    Roeser, H P; Lee, G R; Nacht, S; Cartwright, G E

    1970-12-01

    The importance of ceruloplasmin in iron metabolism was studied in swine made hypoceruloplasminemic by copper deprivation. When the plasma ceruloplasmin level fell below 1% of normal, cell-to-plasma iron flow became sufficiently impaired to cause hypoferremia, even though total body iron stores were normal. When ceruloplasmin was administered to such animals, plasma iron increased immediately and continued to rise at a rate proportional to the logarithm of the ceruloplasmin dose. The administration of inorganic copper induced increases in plasma iron only after ceruloplasmin appeared in the circulation. Thus, ceruloplasmin appeared to be essential to the normal movement of iron from cells to plasma. Studies designed to define the mechanism of action of ceruloplasmin were based on the in vitro observation that ceruloplasmin behaves as an enzyme (ferroxidase) that catalyzes oxidation of ferrous iron. Retention of injected ferrous iron in the plasma of ceruloplasmin-deficient swine was significantly less than that of ferric iron, reflecting impaired transferrin iron binding. Rat ceruloplasmin, which has little ferroxidase activity, was much less effective than porcine or human ceruloplasmin in inducing increases in plasma iron. These observations suggest that ceruloplasmin acts by virtue of its ferroxidase activity. Eight patients with Wilson's disease were evaluated in order to investigate iron metabolism in a disorder characterized by reduced ceruloplasmin levels. Evidence of iron deficiency was found in six of these, and in five of the six, plasma ceruloplasmin was less than 5% of normal. In comparison, the two patients without evidence of iron deficiency had ceruloplasmin levels of 11 and 18% of normal. It is suggested that iron deficiency tends to occur in those patients with Wilson's disease who have the severest degrees of hypoceruloplasminemia, possibly because of defective transfer of iron from intestinal mucosal cells to plasma.

  10. Iron Polymerization and Arsenic Removal During In-Situ Iron Electrocoagulation in Synthetic Bangladeshi Groundwater

    Science.gov (United States)

    van Genuchten, C. M.; Pena, J.; Addy, S.; Gadgil, A.

    2010-12-01

    Millions of people worldwide are exposed to arsenic-contamination in groundwater drinking supplies. The majority of affected people live in rural Bangladesh. Electrocoagulation (EC) using iron electrodes is a promising arsenic removal strategy that is based on the generation of iron precipitates with a high affinity for arsenic through the electrochemical dissolution of a sacrificial iron anode. Many studies of iron hydrolysis in the presence of co-occurring ions in groundwater such as PO43-, SiO44-, and AsO43- suggest that these ions influence the polymerization and formation of iron oxide phases. However, the combined impact of these ions on precipitates generated by EC is not well understood. X-ray absorption spectroscopy (XAS) was used to examine EC precipitates generated in synthetic Bangladeshi groundwater (SBGW). The iron oxide structure and arsenic binding geometry were investigated as a function of EC operating conditions. As and Fe k-edge spectra were similar between samples regardless of the large range of current density (0.02, 1.1, 5.0, 100 mA/cm2) used during sample generation. This result suggests that current density does not play a large role in the formation EC precipitates in SBGW. Shell-by-shell fits of Fe K-edge data revealed the presence of a single Fe-Fe interatomic distance at approximately 3.06 Å. The absence of longer ranged Fe-Fe correlations suggests that EC precipitates consist of nano-scale chains (polymers) of FeO6 octahedra sharing equatorial edges. Shell-by-shell fits of As K-edge spectra show arsenic bound in primarily bidentate, binuclear corner sharing complexes. In this coordination geometry, arsenic prevents the formation of FeO6 corner-sharing linkages, which are necessary for 3-dimensional crystal growth. The individual and combined effects of other anions, such as PO43- and SiO44- present in SBGW are currently being investigated to determine the role of these ions in stunting crystal growth. The results provided by this

  11. Helicobacter pylori antibodies and iron deficiency in female adolescents.

    Directory of Open Access Journals (Sweden)

    Göran Sandström

    Full Text Available OBJECTIVE: Iron deficiency (ID is a common clinical problem worldwide, affecting primarily females. Helicobacter pylori (HP infection has been shown to be associated with ID. The objective of this study was to define the prevalence of HP antibodies in female adolescents, and to find out if there was a correlation between HP infection and ID. The secondary aim was to study if regularly performed sporting activity, have any association to HP infection, in itself. DESIGN: A controlled clinical trial. SETTING: A senior high school in Gothenburg, Sweden. SUBJECTS: All female athletes at a senior high school for top-level athletes were offered to take part, and 56 athletes took part in the study. The control group consisted of a random sample of age-matched non-athlete students of which 71 entered the study. MAIN OUTCOME MEASURES: Iron deficiency (ID and iron deficiency anaemia (IDA were defined by the use of levels of haemoglobin, serum iron, total iron-binding capacity, transferrin saturation, and serum ferritin, as previously described. HP IgG-antibodies were detected by ELISA. RESULTS: 18 of 127 (14% adolescent females had antibodies against HP. Only 3% had IDA, while 50% had ID. In total, 66% of the HP positive females had ID compared to 48% of the negative females (p = 0.203. No correlation between sporting activity and HP infection was found. Regarding ethnicity, 11/28 of subjects from medium-high risk areas were HP-positive, compared to 7/99 coming from low-risk areas (p<0.001. CONCLUSION: The main finding of this study is that the prevalence of HP IgG antibodies was 14% in adolescent females. We could not find any difference regarding frequency of ID and IDA, between HP positive and negative individuals. Ethnicity is of great importance for the risk of HP infection, while sporting activity itself seems to have no association to HP-infection.

  12. [Iron nutrition in Mapuche infants fed with human milk (2d phase)].

    Science.gov (United States)

    Franco, E; Hertrampf, E; Rodríguez, E; Illanes, J C; Palacios, L; Llaguno, S; Lettelier, A

    1990-01-01

    Blood hemoglobin, serum iron, total iron binding capacity (TIBC) and serum ferritin were measured in 140 healthy rural mapuche (southern Chile's indigenous ethnic group) infants aged 8 to 15 months: 90 had been exclusively breast fed for the first 5 or 6 months of life, then solid foods were introduced but cow's milk was never given to them. The remaining 50, which were all weaned at nearly 4 months of age and then given cow's milk and solid foods at the corresponding age, were designated as controls. Anemia was detected in 4.5% of breast fed infants and in 38% of controls. Evidence of iron deficient erythropoiesis was found in 5% and 81% of cases and controls, respectively. Human milk apparently protects this ethnic group from iron deficiency anemia and this protection seems to be better in mapuche infants than in other groups of chilean infants, because these late have shown 30% incidence of anemia around the first year of life in other studies. More studies on differences in iron nutritional state among mapuche and non mapuche are needed and are under way.

  13. Clinical Significance of Reticulocyte Hemoglobin Content in the Diagnosis of Iron Deficiency Anemia

    Directory of Open Access Journals (Sweden)

    Mustafa Karagülle

    2013-06-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the clinical significance of reticulocyte hemoglobin content (CHr in the diagnosis of iron deficiency anemia (IDA and to compare it with other conventional iron parameters. METHODS: A total of 32 female patients with IDA (serum hemoglobin 120 g/L and serum ferritin <20 ng/mL were enrolled. RESULTS: CHr was 24.95±3.92 pg in female patients with IDA and 29.93±2.96 pg in female patients with iron deficiency. CHr showed a significant positive correlation with hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, serum iron, and transferrin saturation and a significant negative correlation with transferrin and total iron-binding capacity. The cut-off value of CHr for detecting IDA was 29 pg. CONCLUSION: Our data demonstrate that CHr is a useful parameter that can be confidently used in the diagnosis of IDA, and a CHr cut-off value of 29 pg predicts IDA.

  14. METABOLISM OF IRON STORES

    OpenAIRE

    Saito, Hiroshi

    2014-01-01

    ABSTRACT Remarkable progress was recently achieved in the studies on molecular regulators of iron metabolism. Among the main regulators, storage iron, iron absorption, erythropoiesis and hepcidin interact in keeping iron homeostasis. Diseases with gene-mutations resulting in iron overload, iron deficiency, and local iron deposition have been introduced in relation to the regulators of storage iron metabolism. On the other hand, the research on storage iron metabolism has not advanced since th...

  15. Copper, ceruloplasmin, superoxide dismutase and iron parameters in Parkinson's disease.

    Science.gov (United States)

    Tórsdóttir, G; Kristinsson, J; Sveinbjörnsdóttir, S; Snaedal, J; Jóhannesson, T

    1999-11-01

    In a previous study we found copper dyshomeostasis in patients with Alzheimer's disease. In this study, levels of copper in plasma, of ceruloplasmin in serum and ceruloplasmin oxidative activity as well as superoxide dismutase (SOD) activity in erythrocytes were determined in 40 patients with Parkinson's disease and their healthy age- and gender-matched controls. Copper concentrations did not differ significantly in the two groups, whereas both ceruloplasmin concentrations and ceruloplasmin oxidative activity were significantly lower in the patients, also relative to ceruloplasmin mass. SOD activity was not significantly different in the two groups but decreased significantly with the duration of disease. The same was found for ceruloplasmin oxidative activity. Ceruloplasmin oxidative activity and SOD activity did not decrease with age. Levels of serum iron, serum ferritin and total iron binding capacity were determined in about 30 of the patients and an equal number of controls and were not found to differ. Transferrin levels were significantly lower in the patients than in their controls but, conversely, the transferrin saturation was significantly higher in the patients. The results indicate that patients with Alzheimer's disease and Parkinson's disease have defective ceruloplasmin and SOD activities in common and that these defects are not necessarily associated with major disturbances in iron homeostasis.

  16. Iron Dextran Injection

    Science.gov (United States)

    ... allergic to iron dextran injection; any other iron injections such as ferric carboxymaltose (Injectafer), ferumoxytol (Feraheme), iron sucrose (Venofer), or sodium ferric gluconate (Ferrlecit);any other ...

  17. Capacity and Capacity Utilization in Fishing Industries

    OpenAIRE

    Kirkley, James E; Squires, Dale

    1999-01-01

    Excess capacity of fishing fleets is one of the most pressing problems facing the world's fisheries and the sustainable harvesting of resource stocks. Considerable confusion persists over the definition and measurement of capacity and capacity utilization in fishing. Fishing capacity and capacity utilization, rather than capital (or effort) utilization, provide the appropriate framework. This paper provides both technological-economic and economic definitions of capacity and excess capacity i...

  18. multicopper oxidases important for human iron metabolism

    Directory of Open Access Journals (Sweden)

    Diana Wierzbicka

    2014-01-01

    Full Text Available Multi-copper oxidases are a group of proteins which demonstrate enzymatic activity and are capable of oxidizing their substrates with the concomitant reduction of dioxygen to two water molecules. For some multi-copper oxidases there has been demonstrated ferroxidase activity which is related to their specific structure characterized by the presence of copper centres and iron-binding sites. Three multi-copper oxidases have been included in this group: ceruloplasmin, hephaestin and zyklopen. Multi copper oxidases which are expressed in different tissues are capable of oxidizing a wide spectrum of substrates. Multi-copper oxidases are capable of oxidizing a wide spectrum of substrates. Ceruloplasmin exhibits antioxidant activity as well as being involved in many other biological processes. The observations of phenotypic effects of absence or low expression of multi-copper ferroxidase-coding genes suggest that the main role of these proteins is taking part in iron metabolism. The main role of ceruloplasmin in iron turnover is oxidizing Fe2+ into Fe3+, a process which is essential for iron binding to transferrin (the main iron-transporting protein, as well as to ferritin (the main iron-storage protein. The function of hephaestin as ferroxidase is essential for iron binding to apotransferrin in the lamina propria of the intestinal mucosa, a process that is important for further transport of iron to the liver by the portal vein. Available data indicate that zyklopen is responsible for the placental iron transport. The presence of three multi-copper oxidases with ferroxidase activity emphasizes the significance of oxidation for iron metabolism. The distribution of multi-copper ferroxidases in many tissues ensures the proper iron turnover in the body as well as preventing toxic effects related to the presence of Fe2+ ions. These ions contribute to generation of free radicals, including the highly reactive hydroxyl radical, through the Fenton and Haber

  19. Characterization of uranium binding to Diphonix{sup TM} and Duolite{sup TM} ion-exchange resins

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, J.G.; Shrinsky, A.J.; Sommerville, L.E. [Fort Lewis College, Durango, CO (United States)]|[Los Alamos National Lab., NM (United States)] [and others

    1995-12-01

    We initiated a series of experiments to characterize uranium binding to two commercially available ion-exchange resins, Diphonix{trademark} and Duolite{trademark}. These experiments were done to determine the most efficient means of recycling an organic chelator, tiron, in a process used to wash soil contaminated with uranium. The binding capacity and pH dependence were determined for uranium binding to Diphonix{trademark} and Duolite{trademark}. Also competition studies with aluminum, iron, and uranium were done to determine the optimum conditions for uranium binding in the presence of these other metals. Both resins were shown to effectively separate uranium from tiron allowing almost quantitative recovery of uranium-free tiron. Furthermore, these resins may serve as a suitable place to concentrate and store uranium.

  20. The iron-regulated staphylococcal lipoproteins

    Directory of Open Access Journals (Sweden)

    Jessica eSheldon

    2012-04-01

    Full Text Available Lipoproteins fulfill diverse roles in antibiotic resistance, adhesion, protein secretion, signaling and sensing, and many also serve as the substrate binding protein (SBP partner to ABC transporters for the acquisition of a diverse array of nutrients including peptides, sugars, and scarcely abundant metals. In the staphylococci, the iron-regulated SBPs are significantly upregulated during iron starvation and function to sequester and deliver iron into the bacterial cell, enabling staphylococci to circumvent iron restriction imposed by the host environment. Accordingly, this subset of lipoproteins has been implicated in staphylococcal pathogenesis and virulence. Lipoproteins also activate the host innate immune response, triggered through Toll-like receptor-2 (TLR2 and, notably, the iron-regulated subset of lipoproteins are particularly immunogenic. In this review, we discuss the iron-regulated staphylococcal lipoproteins with regard to their biogenesis, substrate specificity, and impact on the host innate immune response.

  1. Nutritional zinc status in weaning infants: association with iron deficiency, age, and growth profile.

    Science.gov (United States)

    Park, Jeong Su; Chang, Ju Young; Hong, Jeana; Ko, Jae Sung; Seo, Jeong Kee; Shin, Sue; Lee, Eun Hee

    2012-12-01

    In the present study, we evaluated the correlation between iron deficiency (ID) and zinc deficiency (ZD) and explored the demographic, anthropometric, and feeding-related factors associated with hypozincemia and hair zinc content in weaning infants. Infants aged 6-24 months were recruited, their feeding history was recorded, and their heights and weights were measured. Hemoglobin content, serum iron/total iron-binding capacity, and ferritin and zinc concentrations of serum and hair (using inductively coupled plasma-mass spectroscopy) were assessed. Among 101 infants, 64 (63.4 %) infants exhibited ID. The median serum zinc concentration in iron-deficient infants was lower than that in non-iron-deficient infants, respectively, 73.5 μg/dL (interquartile range [IQR], 65.0-83.8) vs. 87.0 μg/dL (IQR, 77.5-97.0; p = 0.001). The frequency of hypozincemia was also significantly higher in the iron-deficient group than in the non-iron-deficient group (21 out of 64 [32.8 %] vs. 4 out of 37 [10.8 %], respectively; p = 0.014). In multiple regression analysis, the risk of hypozincemia was significantly increased in infants with ID (p = 0.026), mildly underweight infants (weight-for-age Z score status (p > 0.1); however, there was an inverse relationship between hair zinc concentrations and age of infants (r = -0.250; p = 0.024). In weaning infants, ID is a risk factor for hypozincemia. Hair zinc concentrations appeared to decrease as the age of infants increased during late infancy. Further large-scale studies are needed to validate the relationship between hypozincemia and mild degrees of weight gain impairment in this age group.

  2. Iron and hepcidin as risk factors in atherosclerosis: what do the genes say?

    Science.gov (United States)

    Galesloot, Tessel E; Janss, Luc L; Burgess, Stephen; Kiemeney, Lambertus A L M; den Heijer, Martin; de Graaf, Jacqueline; Holewijn, Suzanne; Benyamin, Beben; Whitfield, John B; Swinkels, Dorine W; Vermeulen, Sita H

    2015-07-11

    Previous reports suggested a role for iron and hepcidin in atherosclerosis. Here, we evaluated the causality of these associations from a genetic perspective via (i) a Mendelian randomization (MR) approach, (ii) study of association of atherosclerosis-related single nucleotide polymorphisms (SNPs) with iron and hepcidin, and (iii) estimation of genomic correlations between hepcidin, iron and atherosclerosis. Analyses were performed in a general population sample. Iron parameters (serum iron, serum ferritin, total iron-binding capacity and transferrin saturation), serum hepcidin and genome-wide SNP data were available for N = 1,819; non-invasive measurements of atherosclerosis (NIMA), i.e., presence of plaque, intima media thickness and ankle-brachial index (ABI), for N = 549. For the MR, we used 12 iron-related SNPs that were previously identified in a genome-wide association meta-analysis on iron status, and assessed associations of individual SNPs and quartiles of a multi-SNP score with NIMA. Quartile 4 versus quartile 1 of the multi-SNP score showed directionally consistent associations with the hypothesized direction of effect for all NIMA in women, indicating that increased body iron status is a risk factor for atherosclerosis in women. We observed no single SNP associations that fit the hypothesized directions of effect between iron and NIMA, except for rs651007, associated with decreased ferritin concentration and decreased atherosclerosis risk. Two of six NIMA-related SNPs showed association with the ratio hepcidin/ferritin, suggesting that an increased hepcidin/ferritin ratio increases atherosclerosis risk. Genomic correlations were close to zero, except for hepcidin and ferritin with ABI at rest [-0.27 (SE 0.34) and -0.22 (SE 0.35), respectively] and ABI after exercise [-0.29 (SE 0.34) and -0.30 (0.35), respectively]. The negative sign indicates an increased atherosclerosis risk with increased hepcidin and ferritin concentrations. Our results suggest a

  3. Iron Sucrose Injection

    Science.gov (United States)

    Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due ... and may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called iron ...

  4. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... enough iron, your body starts using the iron it has stored. Soon, the stored iron gets used ... fewer red blood cells. The red blood cells it does make have less hemoglobin than normal. Iron- ...

  5. Effect of daily supplementation with iron and zinc on iron status of childbearing age women.

    Science.gov (United States)

    Mujica-Coopman, María F; Borja, Angélica; Pizarro, Fernando; Olivares, Manuel

    2015-05-01

    The objective was to determine the effect of daily supplementation with 30 mg of iron (Fe) plus 30 mg of zinc (Zn) for 3 months on Fe status of women of childbearing age. This was a randomized double-blind, placebo-controlled trial. Eighty-one women (18-45 years) were randomly assigned to receive either a daily single dose of 30 mg of Fe (group 1; n = 28) and 30 mg of Fe plus 30 mg of Zn (group 2; n = 26) or placebo (n = 27) for 3 months. Hemoglobin (Hb), mean corpuscular volume, serum Fe, total iron-binding capacity, transferrin saturation, erythrocyte Zn protoporphyrin, serum ferritin (SF), serum transferrin receptor (TfR), total body Fe, serum Zn, and high-sensitivity C-reactive protein were measured at baseline and at the end of the study. At baseline, 3.7, 28.4, and 3.7 % of women had iron-deficiency anemia (IDA), Fe deficiency without anemia, and depleted Fe stores, respectively. No significant differences on Fe status were found between groups before supplementation. After supplementation, group 2 showed a significant increase of Hb and total body Fe and a significant decrease of TfR compared with placebo (p < 0.05). Moreover, serum Zn increased significantly in group 2 compared with group 1 (p < 0.01) and placebo (p < 0.01). In conclusion, daily supplementation with 30 mg of Fe plus 30 mg of Zn for 3 months improved significantly the Fe and Zn status of women, compared with those who received placebo. The positive effect of Fe supplementation on Fe status is enhanced by combined Zn supplementation.

  6. Pica associated with iron deficiency or depletion: clinical and laboratory correlates in 262 non-pregnant adult outpatients

    Directory of Open Access Journals (Sweden)

    Barton James C

    2010-12-01

    Full Text Available Abstract Background There are many descriptions of the association of pica with iron deficiency in adults, but there are few reports in which observations available at diagnosis of iron deficiency were analyzed using multivariable techniques to identify significant predictors of pica. We sought to identify clinical and laboratory correlates of pica in adults with iron deficiency or depletion using univariable and stepwise forward logistic regression analyses. Methods We reviewed charts of 262 non-pregnant adult outpatients (ages ≥18 y who required treatment with intravenous iron dextran. We tabulated their sex, age, race/ethnicity, body mass index, symptoms and causes of iron deficiency or depletion, serum iron and complete blood count measures, and other conditions at diagnosis before intravenous iron dextran was administered. We excluded patients with serum creatinine >133 μmol/L or disorders that could affect erythrocyte or iron measures. Iron deficiency was defined as both SF Results There were 230 women (184 white, 46 black; ages 19-91 y and 32 men (31 white, 1 black; ages 24-81 y. 118 patients (45.0% reported pica; of these, 87.3% reported ice pica (pagophagia. In univariable analyses, patients with pica had lower mean age, black race/ethnicity, and higher prevalences of cardiopulmonary and epithelial manifestations. The prevalence of iron deficiency, with or without anemia, did not differ significantly between patients with and without pica reports. Mean hemoglobin and mean corpuscular volume (MCV were lower and mean red blood cell distribution width (RDW and platelet count were higher in patients with pica. Thrombocytosis occurred only in women and was more prevalent in those with pica (20.4% vs. 8.3%; p = 0.0050. Mean total iron-binding capacity was higher and mean serum ferritin was lower in patients with pica. Nineteen patients developed a second episode of iron deficiency or depletion; concordance of recurrent pica (or absence of

  7. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...

  8. Erratum to "Apotransferrin administration prevents growth of Staphylococcus epidermidis in serum of stem cell transplant patients by binding of free iron". [FEMS Immunol. Med Microbiol. 37 (2003) 45-51].

    Science.gov (United States)

    von Bonsdorff, Leni; Sahlstedt, Leila; Ebeling, Freja; Ruutu, Tapani; Parkkinen, Jaakko

    2004-03-08

    We investigated the effect of free, non-transferrin-bound iron occurring in haematological stem cell transplant patients on growth of Staphylococcus epidermidis in serum in vitro, and prevention of bacterial growth by exogenous apotransferrin. S. epidermidis did not grow in normal serum at inoculated bacterial densities up to 10(3) cfu ml(-1) but slow growth could be detected at higher initial inocula. Addition of free iron abolished the growth-inhibitory effect of serum, whereas addition of apotransferrin again restored it. Appearance of free iron and loss of growth inhibition coincided in patient serum samples taken daily during myeloablative therapy. Intravenously administered apotransferrin effectively bound free iron and restored the growth inhibition in patient sera. The results suggest that exogenous apotransferrin might protect stem cell transplant patients against infections by S. epidermidis and possibly other opportunistic pathogens.

  9. Iron deficiency and heart failure: diagnostic dilemmas and therapeutic perspectives.

    Science.gov (United States)

    Jankowska, Ewa A; von Haehling, Stephan; Anker, Stefan D; Macdougall, Iain C; Ponikowski, Piotr

    2013-03-01

    Iron is a micronutrient essential for cellular energy and metabolism, necessary for maintaining body homoeostasis. Iron deficiency is an important co-morbidity in patients with heart failure (HF). A major factor in the pathogenesis of anaemia, it is also a separate condition with serious clinical consequences (e.g. impaired exercise capacity) and poor prognosis in HF patients. Experimental evidence suggests that iron therapy in iron-deficient animals may activate molecular pathways that can be cardio-protective. Clinical studies have demonstrated favourable effects of i.v. iron on the functional status, quality of life, and exercise capacity in HF patients. It is hypothesized that i.v. iron supplementation may become a novel therapy in HF patients with iron deficiency.

  10. Aggregatibacter actinomycetemcomitans QseBC is activated by catecholamines and iron and regulates genes encoding proteins associated with anaerobic respiration and metabolism

    Science.gov (United States)

    Weigel, WA; Demuth, DR; Torres-Escobar, A; Juárez-Rodríguez, MD

    2015-01-01

    Aggregatibacter actinomycetemcomitans QseBC regulates its own expression and is essential for biofilm growth and virulence. However, the signal that activates the QseC sensor has not been identified and the qseBC regulon has not been defined. In this study, we show that QseC is activated by catecholamine hormones and iron but not by either component alone. Activation of QseC requires an EYRDD motif in the periplasmic domain of the sensor and site-specific mutations in EYRDD or the deletion of the periplasmic domain inhibits catecholamine/iron-dependent induction of the ygiW-qseBC operon. Catecholamine/iron-dependent induction of transcription also requires interaction of the QseB response regulator with its binding site in the ygiW-qseBC promoter. Whole genome microarrays were used to compare gene expression profiles of A. actinomycetemcomitans grown in a chemically defined medium with and without catecholamine and iron supplementation. Approximately 11.5% of the A. actinomycetemcomitans genome was differentially expressed by at least two-fold upon exposure to catecholamines and iron. The expression of ferritin was strongly induced, suggesting that intracellular iron storage capacity is increased upon QseBC activation. Consistent with this, genes encoding iron binding and transport proteins were down-regulated by QseBC. Strikingly, 57% of the QseBC up-regulated genes (56/99) encode proteins associated with anaerobic metabolism and respiration. Most of these up-regulated genes were recently reported to be induced during in vivo growth of A. actinomycetemcomitans. These results suggest that detection of catecholamines and iron by QseBC may alter the cellular metabolism of A. actinomycetemcomitans for increased fitness and growth in an anaerobic host environment. PMID:25923132

  11. Non conserved residues between Cqm1 and Aam1 mosquito α-glucosidases are critical for the capacity of Cqm1 to bind the Binary toxin from Lysinibacillus sphaericus.

    Science.gov (United States)

    Ferreira, Lígia Maria; Romão, Tatiany Patrícia; Nascimento, Nathaly Alexandre do; Costa, Maria da Conceição Mendes Ferreira da; Rezende, Antônio Mauro; de-Melo-Neto, Osvaldo Pompílio; Silva-Filha, Maria Helena Neves Lobo

    2014-07-01

    The Binary (Bin) toxin from the entomopathogenic bacterium Lysinibacillus sphaericus acts on larvae of the culicid Culex quinquefasciatus through its binding to Cqm1, a midgut-bound α-glucosidase. Specific binding by the BinB subunit to the Cqm1 receptor is essential for toxicity however the toxin is unable to bind to the Cqm1 ortholog from the refractory species Aedes aegypti (Aam1). Here, to investigate the molecular basis for the interaction between Cqm1 and BinB, recombinant Cqm1 and Aam1 were first expressed as soluble forms in Sf9 cells. The two proteins were found to display the same glycosilation patterns and BinB binding properties as the native α-glucosidases. Chimeric constructs were then generated through the exchange of reciprocal fragments between the corresponding cqm1 and aam1 cDNAs. Subsequent expression and binding experiments defined a Cqm1 segment encompassing residues S129 and A312 as critical for the interaction with BinB. Through site directed mutagenesis experiments, replacing specific sets of residues from Cqm1 with those of Aam1, the 159GG160 doublet was required for this interaction. Molecular modeling mapped these residues to an exposed loop within the Cqm1's structure, compatible with a target site for BinB and providing a possible explanation for its lack of binding to Aam1. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Control of bacterial iron homeostasis by manganese

    Science.gov (United States)

    Puri, Sumant; Hohle, Thomas H.; O'Brian, Mark R.

    2010-01-01

    Perception and response to nutritional iron availability by bacteria are essential to control cellular iron homeostasis. The Irr protein from Bradyrhizobium japonicum senses iron through the status of heme biosynthesis to globally regulate iron-dependent gene expression. Heme binds directly to Irr to trigger its degradation. Here, we show that severe manganese limitation created by growth of a Mn2+ transport mutant in manganese-limited media resulted in a cellular iron deficiency. In wild-type cells, Irr levels were attenuated under manganese limitation, resulting in reduced promoter occupancy of target genes and altered iron-dependent gene expression. Irr levels were high regardless of manganese availability in a heme-deficient mutant, indicating that manganese normally affects heme-dependent degradation of Irr. Manganese altered the secondary structure of Irr in vitro and inhibited binding of heme to the protein. We propose that manganese limitation destabilizes Irr under low-iron conditions by lowering the threshold of heme that can trigger Irr degradation. The findings implicate a mechanism for the control of iron homeostasis by manganese in a bacterium. PMID:20498065

  13. The usefulness of soluble transferrin receptor in the diagnosis and treatment of iron deficiency anemia in children

    Science.gov (United States)

    Yoon, Se Hoon; Kim, Dong Sup; Yu, Seung Taek; Shin, Sae Ron

    2015-01-01

    Purpose Soluble transferrin receptor (sTfR) is a truncated extracellular form of the membrane transferrin receptor produced by proteolysis. Concentrations of serum sTfR are related to iron status and erythropoiesis in the body. We investigated whether serum sTfR levels can aid in diagnosis and treatment of iron deficiency anemia (IDA) in children. Methods Ninety-eight patients with IDA were enrolled and were classified according to age at diagnosis. Group 1 comprised 78 children, aged 6-59 months, and group 2 comprised 20 adolescents, aged 12-16 years. Results In group 1, patients' serum sTfR levels correlated negatively with mean corpuscular volume; hemoglobin (Hb), ferritin, and serum iron levels; and transferrin saturation and positively with total iron binding capacity (TIBC) and red cell distribution width. In group 2, patients' serum sTfR levels did not correlate with ferritin levels and TIBC, but had a significant relationship with other iron indices. Hb and serum sTfR levels had a significant inverse relationship in both groups; however, in group 1, there was no correlation between Hb and serum ferritin levels. In 30 patients of group 1, serum sTfR levels were significantly decreased with an increase in Hb levels after iron supplementation for 1 month. Conclusion Serum sTfR levels significantly correlated with other diagnostic iron parameters of IDA and inversely correlated with an increase in Hb levels following iron supplementation. Therefore, serum sTfR levels can be a useful marker for the diagnosis and treatment of IDA in children. PMID:25729394

  14. Samskabelse og Evaluation Capacity Building

    DEFF Research Database (Denmark)

    2017-01-01

    Styringsparadigmer bærer ikke blot organisationsopskrifter med sig, men også evalueringsopskrifter. Som det fremgår af Kapitel 1, Et nyt styringsparadigme på vej? bærer styringsparadigmet New Public Governance organisationsopskriften samskabelse med sig, men det er endnu ikke tydeligt hvilken eva...... skifte fra en evaluerings¬bølge til en anden kræver, at der sker en Evaluation Capacity Building. Evaluation Capacity Building har dobbelt binding, som dels handler om evnen til at gennemføre evaluering, dels om evnen til at anvende evaluering....

  15. The evaluation of iron deficiency and anemia in male blood donors with other related factors

    Directory of Open Access Journals (Sweden)

    Yousefinejad Vahid

    2010-01-01

    Full Text Available Aims and Background: Iron deficiency is one of the most common nutritional disorders worldwide and blood donation may cause iron depletion. Limited studies with large sample size have been done on male donors. The aim of this study is to determine the prevalence of iron deficiency and iron deficiency anemia among male donors in the Kurdistan Organization of Blood Transfusion in Iran. Materials and Methods: This was a cross-sectional study. Sample size was 1184 blood donors selected by systematic random sampling. Hemoglobin, serum iron, serum ferritin, total iron banding capacity (TIBC and transferin saturation were measured in donors. Iron depletion, lack of iron stores, iron deficiency, iron deficiency anemia and anemia were evaluated among them. Data was analyzed with SPSS software and X΂, one-way ANOVA, and LSD test. Results: Iron deficiency, anemia, iron deficiency anemia, iron depletion and lack of iron resources were seen in 2.3, 4.08, 2.14, 22.76 and 4.66 percent respectively. There was a significant relationship of iron deficiency and iron deficiency anemia with instances of donation and interval from last donation (P < 0.05. A significant relationship was seen between iron deficiency and iron deficiency anemia among blood donors with more than ten times blood donation (P < 0.05. Conclusions: This study showed regular male donors require especial attention. Therefore, serum ferritin is recommended as a more adequate index to use for iron deficiency screening and planning purposes for iron supplementation among them.