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Results 451 - 500 of 1275
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De Windt Wim - - 2003
In the absence of oxygen, a protective H2 film is formed around an Fe(0) surface, inhibiting the electron flow from this surface. Our study of anoxic corrosion of Fe(0) beads revealed that, in the presence of Shewanella oneidensis MR-1, H2 removal and precipitation of Fe mineral particles on the cell ...
Wu S M - - 2003
5-Aminolevulinic acid (ALA) has shown promising in photodynamic detection and therapy of brain tumor. However, the knowledge on selective accumulation of ALA-induced protoporphyrin IX (PpIX) in brain tumor tissue is still fragment. In the present study, the rat C6 glioma cells, human SK-N-SH neuroblastoma cells, and rat normal cerebellar granule ...
Kaufman Christina L - - 2003
Conjugation of dextran-coated superparamagnetic iron oxide (SPIO) particles with transactivator protein (Tat)-peptide and fluorescein isothiocyanate (FITC) allows cells to readily uptake SPIO particles. This makes possible high-resolution, real-time imaging of these cells by magnetic resonance imaging (MRI). First, we need to understand how various subpopulations take up and maintain SPIO ...
Arbab Ali S - - 2003
Superparamagnetic iron oxides (SPIO) are being used to label cells for in vivo monitoring by magnetic resonance imaging (MRI). The purpose of this study is to present protocols using SPIO and a polycationic transfection agent for magnetic labeling of cells as a basis for cellular MRI. Various concentrations of ferumoxides ...
Santos Renata - - 2003
Analysis of Saccharomyces cerevisiae cell transcriptome revealed that iron deprivation/supplementation affects genes other than those of the iron regulon (controlled by Aft proteins). Several genes regulated by zinc (induced by zinc deprivation) were induced by iron. Cells lacking the yeast frataxin homologue Yfh1 accumulate large amounts of iron in their ...
Baulig Augustin - - 2003
Epidemiological studies have associated the increase of respiratory disorders with high levels of ambient particulate matter (PM) levels although the underlying biological mechanisms are unclear. PM are a complex mixture of particles with different origins but in urban areas, they mainly contain soots from transport like Diesel exhaust particles (DEP). ...
Jendelová Pavla - - 2003
Bone marrow stromal cells (MSCs) are pluripotent progenitor cells that have the capacity to migrate toward lesions and induce or facilitate site-dependent differentiation in response to environmental signals. In animals with a cortical photochemical lesion, the fate of rat MSCs colabeled with magnetic iron-oxide nanoparticles (Endorem) and bromodeoxyuridine (BrdU) was ...
Lee Adrian W M - - 2003
The effects of cellular proliferation on the uptake of transferrin-bound iron (Tf-Fe) and expression of transferrin receptor-1 (TfR1) and transferrin receptor-2 (TfR2) were investigated using a human hepatoma (HuH7) cell line stably transfected with TfR1 antisense RNA expression vector to suppress TfR1 expression. At transferrin (Tf) concentrations of 50 nmol/L ...
Tiwari A - - 2003
Magnetic beads (Dynabeads) have been used for the purification of endothelial cells. One application for this procedure may be for single-stage seeding of bypass grafts. The number of endothelial cells (EC) isolated is crucial and therefore to increase the number of cells extracted, a higher number of Dynabeads per cell ...
Killilea David W - - 2003
Iron accumulates as a function of age in several tissues in vivo and is associated with the pathology of numerous age-related diseases. The molecular basis of this change may be due to a loss of iron homeostasis at the cellular level. Therefore, changes in iron content in primary human fibroblast ...
Doulias Paschalis-Thomas - - 2003
The role of endosomal/lysosomal redox-active iron in H2O2-induced nuclear DNA damage as well as in cell proliferation was examined using the iron chelator desferrioxamine (DFO). Transient transfections of HeLa cells with vectors encoding dominant proteins involved in the regulation of various routes of endocytosis (dynamin and Rab5) were used to ...
Shackelford Rodney E - - 2003
Ataxia-telangiectasia (AT) is an autosomal recessive disorder characterized by genomic instability, chronic oxidative damage, and increased cancer incidence. Compared to normal cells, AT cells exhibit unusual sensitivity to exogenous oxidants, including t-butyl hydroperoxide (t-BOOH). Since ferritin releases labile iron under oxidative stress (which is chronic in AT) and labile iron ...
Sturm Brigitte - - 2003
Intravenous iron, used for the treatment of anemia in chronic renal failure and other diseases, represents a possible source of free iron in tissue cells, particularly in the liver. In this study we examined the effect of different sources of intravenous iron (IVI) on the labile iron pool (LIP) which ...
He Yi - - 2003
Though increasing lines of evidence suggest that iron accumulation and iron-induced oxidative stress might be important pathological factors responsible for substantia nigra (SN) cell death in Parkinson's disease (PD), it is still unknown whether iron accumulation is a primary cause or consequence of nigral cell death. Using nuclear microscopy, iron ...
Bencheikh-Latmani Rizlan - - 2003
This study investigated the partitioning of uranyl within a quaternary system made up of uranyl, citrate, goethite, and the bacterium Pseudomonas fluorescens. In the absence of cells, uranyl was sorbed to goethite as a complex involving surface groups and/or citrate. Measurements of the evolution of CO2 indicated that the addition ...
Mori Kiyoshi - - 2003
Conversion of renal mesenchyme into epithelia depends on the ureteric bud, but its specific actions are not established. From conditioned media of ureteric bud cells, we have identified molecules that mimic the growth and epithelialization of mesenchyme in vivo. LIF targets late epithelial progenitors surrounding the ureteric bud, and in ...
Strouhal Martin - - 2003
The bioaccumulation of heavy metals (cadmium, nickel, cobalt and zinc) and the effect of these metals on the production of metallothionein and metallothionein-like proteins (MT) in Yarrowia lipolytica was studied by electrochemical methods. The concentrations of heavy metals were determined by differential pulse voltammetry (DPV). A combination of the constant ...
Lee Jung-Lim - - 2003
Human heavy chain ferritin (H-ferritin) was cloned from human heart cDNA library and expressed in Pichia pastoris. The H-ferritin transformant was cultivated by fed-batch and the cell mass reached about 52 g cell dry wt l(-1) after 150 h. In atomic absorption spectrometry analysis, intracellular content of iron in H-ferritin ...
Goldstein Laurel - - 2003
Hemin is released from hemoglobin after CNS hemorrhage and is present at high micromolar concentrations in intracranial hematomas. This highly reactive compound is potentially cytotoxic via a variety of oxidative and nonoxidative mechanisms. However, despite its clinical relevance, little is known of its effect on neuronal cells. In this study, ...
McGugan Glen C GC - - 2003
The Entamoeba histolytica Rab11 family of small molecular weight GTPases consists of three members, EhRab11, EhRab11B, and EhRab11C. The functions of these Rabs in Entamoeba have not been determined. Therefore, as an approach to elucidate the role of the Rab11 family of GTPases in Entamoeba, immunofluorescence microscopy was undertaken to ...
Wu Shu-Min - - 2003
5-aminolevulinic acid (ALA) and its hexyl-ester (He-ALA) has shown promising results in photodynamic detection and therapy of tumors. In this work, the photodynamic effects of ALA and He-ALA on neuroblastoma cells, hepatoma cells and fibroblast cells were comparatively studied. With the detection of fluorescence emission spectra, protoporphyrin IX (PpIX) induced ...
Frank Joseph A - - 2003
PURPOSE: To label mammalian and stem cells by combining commercially available transfection agents (TAs) with superparamagnetic iron oxide (SPIO) magnetic resonance (MR) imaging contrast agents. MATERIALS AND METHODS: Three TAs were incubated with ferumoxides and MION-46L in cell culture medium at various concentrations. Human mesenchymal stem cells, mouse lymphocytes, rat ...
Scheiber-Mojdehkar Barbara - - 2003
It is widely assumed that standard parenteral iron preparations are degraded in the reticuloendothelial cells and that the iron is subsequently incorporated into transferrin. Hepatocytes or other epithelial cells have been considered as not affected. We show that this picture should be carefully reconsidered. By using the human hepatoma cell ...
Ghio Andrew J - - 2003
Lung cells import iron across the plasma membrane as ferrous (Fe2+) ion by incompletely understood mechanisms. We tested the hypothesis that human bronchial epithelial (HBE) cells import non-transferrin-bound iron (NTBI) using superoxide-dependent ferri-reductase activity involving anion exchange protein 2 (AE2) and extracellular bicarbonate (HCO3-). HBE cells that constitutively express AE2 ...
Arredondo Miguel - - 2003
Despite important advances in the understanding of copper secretion and excretion, the molecular components of intestinal copper absorption remain a mystery. DMT1, also known as Nramp2 and DCT1, is the transporter responsible for intestinal iron uptake. Electrophysiological evidence suggests that DMT1 can also be a copper transporter. Thus we examined ...
Pietrangelo Antonello - - 2003
Iron is an essential micronutrient. However, because human beings have no means to control iron excretion, excess iron, regardless of the route of entry, accumulates in parenchymal organs and threatens cell viability. Indeed, when iron-buffering capability is overwhelmed, oxidative stress-induced cell damage and fibrogenesis may arise, mainly in the liver, ...
Lee Sun Ok - - 2003
Conjugated linoleic acid (CLA) was produced at 300 mg l(-1) after 24 h culture of Lactobacillus reuteri in de Man-Rogosa-Sharpe medium containing 0.9 g linoleic acid (LA) l(-1) and 1.67% (v/v) Tween 80. CLA was mainly located in the extracellular space of the cells. Washed cells previously grown on LA ...
Blend Michael J - - 2003
The goal of this investigation was to develop stable radioimmunoconjugates (RICs) of anti-HER2/neu monoclonal antibodies (MoAbs) for imaging and therapy in an animal model bearing human breast tumor xenografts that express normal (MCF-7 cells) and increased amounts of HER2/neu receptors (HCC-1954, BT-474, SKBR-3 cells) on their cell surface membranes. Pharmacy-grade ...
Chitambar Christopher R - - 2003
Recent studies have revealed that the wild-type hemochromatosis protein (HFE) interacts with the transferrin receptor (TfR) and modulates TfR-mediated iron uptake by cells. Because of similarities in the transport of gallium and iron and the use of (67)Ga scanning in lymphoid malignancies, we examined the effect of HFE expression on ...
Yu Zhengquan - - 2003
As a result of continuous digestion of iron-containing metalloproteins, the lysosomes within normal cells contain a pool of labile, redox-active, low-molecular-weight iron, which may make these organelles particularly susceptible to oxidative damage. Oxidant-mediated destabilization of lysosomal membranes with release of hydrolytic enzymes into the cell cytoplasm can lead to a ...
Dominici Silvia - - 2003
BACKGROUND: The molecular mechanisms by which iron is physiologically transported trough the cellular membranes are still only partially understood. Several studies indicate that a reduction step of ferric iron to ferrous is necessary, both in the case of transferrin-mediated and transferrin-independent iron uptake. Recent studies from our laboratory described gamma-glutamyltransferase ...
Griffiths William J H - - 2003
Mutations in the HFE gene and a newly identified second transferrin receptor gene, TfR2, cause hemochromatosis. The cognate proteins, HFE and TfR2, are therefore of key importance in human iron homeostasis. HFE is expressed in small intestinal crypt cells where transferrin-iron entry may determine subsequent iron absorption by mature enterocytes, ...
Lara Flavio Alves - - 2003
The hard tick Boophilus microplus ingests large volumes of cattle blood, as much as 100 times its own mass before feeding. Huge amounts of haem are produced during haemoglobin digestion, which takes place inside acidic lysosomal-type vacuoles of the digest cells of the midgut. Haem is a promoter of free ...
Smith Jacqueline J - - 2003
Concentrations of ferritin in alveolar cells and on the alveolar surface are increased in patients with a variety of respiratory disorders. Ferritin synthesis by cells is modulated by iron content but is also influenced by stimuli other than iron. In this study we sought to determine whether in vitro exposure ...
Bridle Kim R - - 2003
Activated hepatic stellate cells have been implicated in the fibrogenic process associated with iron overload, both in animal models and in human hemochromatosis. Previous studies have evaluated the role of ferritin/ferritin receptor interactions in the activation of stellate cells and subsequent fibrogenesis; however, the role of transferrin in hepatic stellate ...
Chan Wood Yee - - 2003
Trichosanthin (TCS) is a ribosome inactivating protein (RIP). It is generally believed that its many biological activities act through inhibition of ribosomes resulting in a decrease in protein synthesis. It has been hypothesized that the rate of entry of TCS into cells to reach ribosomes is an important factor in ...
Savigni Donna L - - 2003
The aim of this investigation was to determine the mechanism of action of the nitrosophenylpyridine derivative of nifedipine ("nitrosonifedipine", NN) on Fe(II) transport into erythrocytes. Nifedipine is rapidly degraded to NN by daylight. We used rabbit erythrocytes, NN, and several chemically related substances, and examined their effects on the transfer ...
Hinds Kathleen A - - 2003
Tracking transplanted stem cells using magnetic resonance imaging (MRI) could offer biologic insight into homing and engraftment. Ultrasmall dextran-coated iron oxide particles have previously been developed for uptake into cells to allow MRI tracking. We describe a new application of much larger, micron-scale, iron oxide magnetic particles with enhanced MR ...
Kalivendi Shasi V - - 2003
1-Methyl-4-phenylpyridinium (MPP(+)) is a neurotoxin used in cellular models of Parkinson's Disease. Although intracellular iron plays a crucial role in MPP(+)-induced apoptosis, the molecular signalling mechanisms linking iron, reactive oxygen species (ROS) and apoptosis are still unknown. We investigated these aspects using cerebellar granule neurons (CGNs) and human SH-SY5Y neuroblastoma ...
Michel Rosana B - - 2003
We previously found that (67)Ga was more potent and more specific in single-cell kill than other Auger electron emitters and beta-particle emitters, using an anti-CD74 antibody (Ab) (major histocompatibility complex [MHC] class II invariant chain). Because anti-CD74 Abs follow an unusual processing pathway, with rapid delivery in very large amounts ...
Oda Ryo - - 2003
Membrane-bound transferrin-like protein (MTf), a glycosylphosphatidylinositol-anchored protein, is expressed at high levels in many tumors and in several fetal and adult tissues including cartilage and the intestine, as well as in the amyloid plaques of Alzheimer's disease, although its role remains unknown. MTf is one of the major concanavalin A-binding ...
Tagliafico Enrico - - 2003
The nonreceptor tyrosine kinase Fes is implicated in myeloid cells differentiation. It has been observed that its localization can be cytoplasmic, perinuclear, or nuclear. To further characterize this point, we studied Fes subcellular localization in myeloid cell lines (HL60 and K562) and in COS1 cells. Fes was observed in both ...
Kim Eung Il - - 2003
The inhibitory effects of tetrahydropapaveroline on serotonin biosynthesis in serotonin-producing murine mastocytoma P815 cells were investigated. Tetrahydropapaveroline decreased serotonin content in a concentration-dependent manner in P815 cells and showed 44.9% reduction of serotonin content at a concentration of 5.0 microM for 24 h. The value of 50% inhibitory concentration, IC(50), ...
Núñez Marto T - - 2003
The love-hate relationship between iron and living matter has generated mechanisms to maintain iron concentration in a narrow range, above and below which deleterious effects occur. At the cellular level, iron homeostasis is accomplished by the activity of the IRP proteins, which, under conditions of iron depletion, up-regulate the expression ...
Wang L - - 2003
Ni2+ and Cu2+ are the major heavy metal ions in electroplating wastewater of Hong Kong. In the present study, Pseudomonas putida 5-x cell biomass was used to remove Ni2+ from electroplating effluent. Ni2+ adsorption capacity of P. putida 5-x cell biomass cultured in sulphate-limiting medium was found to be minimum ...
Tallkvist Jonas - - 2003
Divalent Metal Transporter 1 (DMT1) is a transmembrane transporter located at the apical membrane of enterocytes and implicated in the duodenal uptake of iron. Results from expression experiments in Xenopus oocytes indicate that DMT1 can mediate transport of a wide range of divalent metals other than iron. The aim of ...
George Dennis - - 2003
A subsurface flow constructed wetlands system was used in this pilot-scale field study to treat runoff from a container nursery. The goal of the study was to determine the statistical significance of certain factors on the removal of simazine (2-chloro-4,6-bis[ethylamino]-s-triazine) and metolachlor (2-chloro-N-[2-ethyl-6-methylphenyl]-N-[2-methoxy-1-methylethyl] acetamide). The factors analyzed included the hydraulic ...
Mazmanian Sarkis K - - 2003
The cell wall envelope of Gram-positive pathogens functions as a scaffold for the attachment of virulence factors and as a sieve that prevents diffusion of molecules. Here the isd genes (iron-regulated surface determinant) of Staphylococcus aureus were found to encode factors responsible for hemoglobin binding and passage of heme-iron to ...
Ridgway Tisha D - - 2003
OBJECTIVE: To determine whether transitional cell carcinoma (TCC) cells incubated in media containing 5-aminolevulinic acid (ALA) would produce sufficient protoporphyrin IX (PpIX) to cause lethal phototoxic effects when exposed to 635-nm light. SAMPLE POPULATION: Canine TCC cells (K9TCC). PROCEDURE: Cultured K9TCC cells were exposed to graded doses of ALA, and ...
van den Bos Ewout J - - 2003
Labeling stem cells with FDA-approved superparamagnetic iron oxide particles makes it possible to track cells in vivo with magnetic resonance imaging (MRI), but high intracellular levels of iron can cause free radical formation and cytotoxicity. We hypothesized that the use of cationic liposomes would increase labeling efficiency without toxic effects. ...
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