SEARCH · Search PubMed
Results for “Iron Compounds”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Serum iron in the Tswana (Bechuanaland).
Explore the source record for details and available documents.
[Incidence of iron deficiency among 462 cases in an extensive polyclinical material].
Explore the source record for details and available documents.
Process performance and change in sludge characteristics during anaerobic digestion of sewage sludge with ozonation.
A new process configuration combining anaerobic digestion with ozonation, and operated at long SRT, was studied with the objective of on-site reduction in sludge quantity and improving biogas recovery. The process performance with respect to solid reduction efficiency and other important process parameters like accumulation of inorganic solids, changes in sludge viscosity and dewatering characteristics were evaluated from the data of long term pilot scale continuous experiments conducted using a mixture of primary and secondary municipal sewage sludge. Due to sludge ozonation and long SRT, high VSS degradation efficiency of approximately 80% was achieved at a reactor solid concentration of 6.5%. A high fraction of inorganic solid (>50%) consisting mainly of acid insoluble and iron compounds was found to accumulate in the reactor. The high inorganic content accumulated in the digested sludge did not, however, contribute to the observed increase in sludge viscosity at high solid concentration. The sludge viscosity was largely found to depend on the organic solid concentration rather than the total solid content. Moreover, higher inorganic content in the digested sludge resulted in better sludge dewaterability. For a quick assessment of the economic feasibility of the new process, an economic index based on the unit cost of digested sludge disposal to unit electric cost is proposed.
Intravenous iron therapy in renal failure: friend and foe?
Anemia is a common feature of chronic renal dysfunction and is associated with significant morbidity and mortality. Although acquired insufficiency of erythropoietin is virtually universal, iron deficiency is also a common contributor to the development of anemia. Iron replacement, in particular via the intravenous route, has become commonplace and results in improved hematocrits either on its own or in association with an erythropoiesis stimulating agent. However, intravenous iron is not without its potential complications. These include acute allergic reactions, iron overload, potentially accelerated cardiovascular disease and risk of infection. It is the purpose of this review to critically evaluate the available clinical and experimental evidence linking iron supplementation therapy with these complications.
Supporting epoetin alfa stimulated erythropoiesis: identifying appropriate iron levels: case study of the anemic patient.
Stimulation of red blood cell precursors by Epoetin alfa results in a predictable, dose-dependent increase in red blood cell mass. Iron is an important substrate that supports red blood cell and hemoglobin development. Patients who receive Epoetin alfa therapy typically require intravenous iron supplementation to ensure proper red cell formation. Target and ceiling iron levels should be determined on the basis of safety considerations, the predicted clinical response, and individual patient replacement needs. Nurses can use clinical parameters such as body weight, baseline and target hemoglobin values, and iron losses from blood and other sources to estimate iron replacement doses, thereby providing a guide for appropriate iron replacement.
Iron and dental caries.
Studies of human and animal caries, experiments in vitro and laboratory reports initiated the present study of a possible caries preventing effect of iron. The study comprises two sections. (I) Coatings on teeth of hamsters treated with iron salts and films formed on various solutions containing ferrous ions were examined with scanning electron microscopy and x-ray fluorescence analysis. (II) Enamel surface layers, remineralized caries lesions, fluorosed rat bone, coatings on teeth of hamsters treated with iron salts and films formed on solutions containing ferrous ions were examined with transmitting electron microscopy and electron diffraction. Based on the findings the following effects were visualized. When brought into the mouth, even in small amounts, iron ions will be precipitated on the enamel surface as thin acid resistant coatings containing gels and crystals of hydrous iron oxides. In addition, by adsorbing salivary calcium and phosphate ions these iron compounds seem to be able to nucleate the formation of apatites, thus mediating a replacement of minerals, which have been dissolved during the acid phases of the caries process.
[Pathogenesis of spontaneous chronic polyarthritis in MRL mice].
In a sequential study the pathogenesis of chronic polyarthritis occurring spontaneously in MRL mice was analysed by light microscopy. A total of 128 MRL mice of both substrains (MRL/Mp-lpr/lpr and +/+) and different age groups was studied. In 50 lpr/lpr mice, tinctorial and histochemical methods were applied for the identification of fibrin/fibrinoid, iron compounds, amyloid, and proteoglycan. The earliest lesions seen in mice of substrain lpr/lpr at the age of 2 months were proliferation of synovial lining cells and loss of tinctorially demonstrable proteoglycan in the articular cartilage. Beginning at 3 months, severe joint destruction associated with pannus formation was encountered usually in knee, carpal and tarsal joints. Besides inflammatory processes in tendons, nerves and musculature fibrinoid-necrotising panarteritis occurred in the intra- and extraarticular tissue. Furthermore, fibrin-containing exudations and deposits of fibrinoid material, occurred in the synovium of large joints and in the periarticular connective tissue of phalangeal joints. The occurrence of these morphological changes, destructive arthritis, vasculitis and periarticular inflammatory changes, was, at the age of 3 months, associated with a highly significant increase of circulating immune complexes. In mice of substrain +/+ aged 1 year and older, arthritic changes with synovial lining cell proliferation, cartilage destruction and inflammatory periarticular lesions developed.
[The occupational risk in the manufacture of mineral pigments and iron oxide dyes].
The mineral pigments and ferric oxide dyes are used on a large scale in the paint and varnish industry, in building, chemical industry, polygraphy etc. For their production as basic raw materials are used lead, chromium and iron compounds. The concentrations of the toxic and accummulating lead and chromium in the air of the work environment surpass MAC and create most frequently "especially unfavourable" conditions of work. In all industrial processes the leading unfavourable factor is the chemical combined with unfavourable physical factors and overstress on the locomotor system. Changes were established in the organism of examined workers as result from the chronic effect of the factors of the work environment of the peripheral blood, digestive, nervous system and the skin. In view of reducing the risk of exposure to the toxic chemical factor it is imposed to take measures for sanitation of the work environment.
Orcein positive hepatocellular material in long-standing biliary diseases. II. Ultrastructural studies.
An ultrastructural study of liver cells was performed on 4 patients with primary biliary cirrhosis (PBC) and on 3 patients with chronic active hepatitis (CAH). In liver cells of PBC patients large (ad 2-3 mu in diameter) particles were seen, which morphologically resembed autophagic vacuoles or large secondary lysosymes. The morphology, size, location, and quantity of these particles corresponded to the orcein positive material seen in light microscopy of adjacent sections in specimens from PBC patients. These large particles were not seen in liver cells of CAH patients, which also lacked the orcein positive material in light microscopy. The author suggests that the observed particles indicate the activation of lysosomal compartment in liver cells in PBC, and that the orcein positive material (copper-protein complex accumulating in liver cells in chronic cholestasis) is taken into the phagolysosomal metabolism and processing in liver cells, and possibly resembles in this respect the intracellular metabolism of iron-compounds.
[Clinical and morphological findings and problems in malacoplakia of the urinary bladder (author's transl)].
Malacoplakia of the urinary bladder (observations on 4 female patients, average age 47 years, longest duration 8 years) is, under light microscopy, arranged in 4 layers. Zone 1 contains inflammatory granulation tissue. Zone 2 is composed of von Hansemann cells (macrophages). In zone 3, Michaelis-Gutmann bodies appear. Finally, the deepest zone 4 contains connective tissue, blood vessels, and lymphoplasmacellular infiltrates. By electron microscopy, the gradual formation of residual bodies from the remains of phagocytosed materials in the macrophages in these layers can be observed. Through loading with calcium and iron compounds, the residual bodies take on the characteristic appearance of Michaelis-Gutmann bodies. Etiologically, the origin of malacoplakia is probably involved with coliform bacteria, but apparently additional factors are required for the development of a disease process: e.g., disturbance of macrophage function. There are certain parallels between malacoplakia and Whipple's disease. With atypical localization outside the urinary bladder, differential diagnostic difficulties can arise in separating malacoplakia from inflammatory-granulomatous processes (granulomatous orchitis, xanthogranulomatous pyelonephritis). The prognosis of malacoplakia in the urinary bladder is good in all cases, but timely treatment of recurrence and constant supervision are indicated.
Studies on porphyrin metabolism in the kidney. Effects of trace metals and glutathione on renal uroporphyrinogen decarboxylase.
Uroporphyrinogen (urogen) decarboxylase catalyzes the decarboxylation of 8- to 4-carboxyl porphyrinogen during heme biosynthesis in mammalian tissues. The specific activity of renal urogen decarboxylase was shown to be approximately one-third that of the hepatic enzyme and to be readily inactivated by HgCl2 following acute treatment or at concentrations as low as 50 microM in vitro. HgCl2 differentially inhibited the decarboxylation of 8- to 7- and 7- to lesser-carboxylated porphyrinogens in the kidney, suggesting that at least a two-stage process is involved in the catalytic action of the renal enzyme. In contrast, neither lead nor iron compounds inhibited renal urogen decarboxylase in concentrations as high as 1 mM in the reaction mixture. GSH increased renal but not hepatic urogen decarboxylase activity by over 4-fold in vitro when measured as total porphyrinogen products produced, and preferentially accelerated the decarboxylation of 7- to 4-carboxyl porphyrinogen. GSH also protected the renal enzyme from HgCl2 inhibition. These findings suggest that renal urogen decarboxylase catalyzes porphyrin decarboxylation significantly less rapidly than the hepatic enzyme, is readily inactivated by mercuric chloride, and may be GSH-dependent with respect to achieving optimal catalytic activity. These observations may be useful in characterizing the contribution of the kidney to the clinical manifestations of the inherited porphyrias and environmentally induced disorders of porphyrin metabolism.
The preparation, properties and action on Staphylococcus aureus of purified fractions from the cationic proteins of rabbit polymorphonuclear leucocytes.
A micropreparative electrophoresis system for purifying the major staphylocidal fractions of cationic proteins from rabbit polymorphonuclear leucocytes is described. The most staphylocidal fraction prepared is also the most cationic and contains two bands migrating immediately behind protamine sulphate on analytical acid gel electrophoresis. SDS gel electrophoresis indicates that these proteins have low molecular weights between 3,500 and 14,400. The staphylocidal activity of the fraction is affected in the same manner as a crude extract of rabbit PMN granules by iron compounds, respiratory inhibitors, and compounds affecting energy transfer and oxidative phosphorylation. It is stable to heating up to 80 degrees and amino acid analysis shows that it contains 24% arginine. Electron microscopy of staphylococcal spheroplasts treated with the purified fraction or with the crude extract shows that they both have a very marked "blebbing" and distorting action on the double membrane. Comparisons are made between the action of the purified fraction and protamine, and it is concluded that they have very similar, although not identical, properties and actions on staphylococci.
[Effects of iron deficiency on expression of transferrin receptor in human lymphocytes].
Cell culture in vitro, ABC-ELISA,RNA dot blot and atom absorption spectrum analysis were used to study biological effects of low concentration of iron citrate (Fe-cit) on the expression of transferrin receptor (TfR) in healthy human peripheral lymphocytes. Results showed that TfR increased by 36%, 50%, and 67% in groups with 1.25 x 10(-5), 5 x 10(-6) Fe-cit and without it, respectively as compared with a control group with 2.5 x 10(-5) mol/L Fe-cit. Levels of TfR-mRNA also increased with decrease of iron in substrate. Iron concentration within cells correlated inversely to the change in the number of TfR. It indicated that iron deficiency could regulate the number of TfR in lymphocytes and its gene expression.
[Studies on the effect of iron on the metabolism of aromatic nitroamino compounds. Effect of organ iron on the metabolism of nitrobenzene].
Explore the source record for details and available documents.
Interactions of iron-thiol-nitrosyl compounds with the phosphoroclastic system of Clostridium sporogenes.
Certain reagents, such as ascorbate or iron salts and thiols, enhance the bacteriostatic action of nitrite on food-spoilage bacteria. This may be due to the formation of nitric oxide and iron-thiol-nitrosyl [( Fe-S-NO]) complexes. The minimum concentrations of these reagents required to inhibit growth of Clostridium sporogenes were investigated. A mixture of nitrite (0.72 mM) with iron (1.44 mM) and cysteine (2.16 mM) was found to be extremely inhibitory when autoclaved and diluted into the culture medium. This mixture caused rapid cessation of growth and loss of cell viability at a final concentration corresponding to 40 microM-nitrite. If added to the initial culture medium, it prevented growth at 5 microM-nitrite. The mixture was more inhibitory, on the basis of the nitrite concentration used, than the 'Perigo factor', obtained by autoclaving nitrite in growth medium. [Fe-S-NO] compounds of known chemical structure were tested to determine if they were responsible for this effect. Total inhibition of cell growth was observed with the tetranuclear clusters [Fe4S3(NO)7] (Roussin's black salt), [Fe4S4(NO)4] or [Fe4Se3(NO)7], added at concentrations equivalent to 10 microM-nitrite, or with [Fe2(SMe)2(NO)4] (methyl ester of Roussin's red salt), equivalent to 200 microM-nitrite. The rate of hydrogen production in growing cell cultures was inhibited by [Fe4S3(NO)7] at levels equivalent to 2.5 microM-nitrite. EPR spectra of the inhibited cells showed features with g-values of 2.03, characteristic of mononuclear iron-nitrosyl species, and, under non-reducing conditions, an unusual signal at g = 1.65. There was no correlation between growth inhibition and the g = 2.03 signal, though there was a better correlation between inhibition and the g = 1.65 signal. The direct effects of the compounds were tested on the iron-sulphur proteins of the phosphoroclastic system, namely ferredoxin, pyruvate-ferredoxin oxidoreductase and hydrogenase. EPR spectra and enzyme assays showed that these proteins were not destroyed by [Fe4S3(NO)7], [Fe4S4(NO)4], [Fe2(SMe)2(NO)4], [Fe(SPh)2(NO)2], or M2 (an autoclaved mixture of 66 mM-cysteine, 3.6 mM-FeSO4 and 0.72 mM-NaNO2) at concentrations higher than those that caused total inhibition of cell growth. Inhibition of cells by [Fe-S-NO] compounds is unlikely to be due to interaction with the preformed enzymes. The possible formation of iron-nitrosyl complexes in vivo, and their inhibitory actions, are discussed.
Non-iron metalloporphyrins: potent antibacterial compounds that exploit haem/Hb uptake systems of pathogenic bacteria.
A new group of potent antibacterial compounds, non-iron metalloporphyrins (MPs), is described. MPs possess a strong antibacterial activity against Gram-positive bacteria, Gram-negative bacteria and mycobacteria. Anaerobically grown bacteria and microorganisms that do not respire and/or express haem uptake systems were resistant to MPs. Antibacterial activity of MPs was not affected by known antibiotic resistance mechanisms operating in bacteria. The most potent MP against Y. enterocolitica, methicillin-resistant S. aureus and M. smegmatis was gallium protoporphyrin IX (Ga-PPIX). When tested alone, Ga ions and metal-free porphyrins had approximately 100-fold higher minimum inhibitory concentration (MIC) values for these organisms. Ga-PPIX was not degraded by MP-sensitive bacteria, indicating that the whole molecule is responsible for antibacterial activity. MPs are antibacterial 'Trojan horses', as they exploit haem transport systems of Gram-negative bacteria as portals of entry into the cell. Bacterial mutants in superoxide dismutases, catalases and stationary-phase sigma factors were hypersensitive to Ga-PPIX. The extreme sensitivity of sod mutants to MPs and the requirement for active respiration for MP activity suggests that these compounds stimulate the production of reactive oxygen radicals in bacteria. Ga-PPIX was not toxic to primary human fibroblasts, several established cell lines and experimental animals at concentrations > 100-fold higher than the MIC for sensitive bacteria.