Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Prussian Blue Reaction”

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.

At least 145 records · Page 8Linked to original sources
PubMed2003

Cluster-to-metal magnetic coupling: synthesis and characterization of 25-electron [Re6-nOsnSe8(CN)6](5-n)-(n = 1, 2) clusters and (Re6-nOsnSe8[CNCu(Me6tren)]6)9+(n = 0, 1, 2) assemblies.

The first face-capped octahedral clusters with 25 metal-based valence electrons are shown to provide versatile building units capable of engaging in magnetic exchange coupling. Reactions of [Re(5)OsSe(8)Cl(6)](3-) and [Re(4)Os(2)Se(8)Cl(6)](2-) with NaCN in a melt of NaNO(3) or KCF(3)SO(3) afford the 24-electron clusters [Re(5)OsSe(8)(CN)(6)](3-) and [Re(4)Os(2)Se(8)(CN)(6)](2-). The 13C NMR spectrum of a 13C-labeled version of the latter species indicates a 1:2 mixture of cis and trans isomers. Cyclic voltammograms of the clusters in acetonitrile display reversible [Re(5)OsSe(8)(CN)(6)](3-/4-), cis-[Re(4)Os(2)Se(8)(CN)(6)](2-/3-), and trans-[Re(4)Os(2)Se(8)(CN)(6)](2-/3-) couples at E(1/2) = -1.843, -0.760, and -1.031 V vs FeCp(2)(0/+), respectively, in addition to other redox processes. Accordingly, reduction of [Re(5)OsSe(8)(CN)(6)](3-) with sodium amalgam and [Re(4)Os(2)Se(8)(CN)(6)](2-) with cobaltocene produces the 25-electron clusters [Re(5)OsSe(8)(CN)(6)](4-) and [Re(4)Os(2)Se(8)(CN)(6)](3-). EPR spectra of these S = 1/2 species in frozen DMF solutions exhibit isotropic signals with g = 1.46 for the monoosmium cluster and g = 1.74 and 1.09 for the respective cis and trans isomers of the diosmium cluster. In each case, results from DFT calculations show the unpaired spin to delocalize to some extent into the pi* orbitals of the cyanide ligands, suggesting the possibility of magnetic superexchange. Reaction of [Re(5)OsSe(8)(CN)(6)](3-) with [Ni(H(2)O)(6)](2+) in aqueous solution generates the porous Prussian blue analogue Ni(3)[Re(5)OsSe(8)(CN)(6)](2).32H(2)O; however, the tendency of the 25-electron clusters to oxidize in water prohibits their use in reactions of this type. Instead, a series of cyano-bridged assemblies, [Re(6-n)Os(n)Se(8)[CNCu(Me(6)tren)](6)](9+) (n = 0, 1, 2; Me(6)tren = tris(2-(dimethylamino)ethyl)amine), were synthesized to permit comparison of the exchange coupling abilities of clusters with 23-25 electrons. As expected, the results of magnetic susceptibility measurements show no evidence for exchange coupling in the assemblies containing the 23- and 24-electron clusters, but reveal the presence of weak ferromagnetic coupling in [Re(4)Os(2)Se(8)[CNCu(Me(6)tren)](6)](9+). Assuming all cluster-Cu(II) exchange interactions to be equivalent, the data were fit to give an estimated coupling strength of J = 0.4 cm(-1). To our knowledge, the ability of such clusters to participate in magnetic exchange coupling has never previously been demonstrated.

Journal Article↗
PubMed2005

A new label-free amperometric immunosenor for rubella vaccine.

A novel label-free amperometric immunosensor for the detection of rubella vaccine was developed by immobilizing anti-rubella serum on bilayer nano-Au/polymerized o-phenylenediamine film with electrodeposited Prussian Blue (PB) as an electrode transfer mediator on the platinum electrode. The redox reactions of PB as a probe on the platinum surface were blocked due to the binding of the antibody to the antigen, which was investigated by cyclic voltammetry. Therefore, the interaction of the antibody with various concentrations of antigen could be detected by measurements of amperometric response in PBS, and the amperometric response on the surface of the modified electrode was inversely proportional to the concentration of rubella vaccine in the sample. The immunosensor showed a specific response to rubella vaccine in the range 8.1x10(-8)-8.0x10(-6) lgCCID50/ml (cell culture infectious dose) and a detection limit of 4.010(-8) lgCCID50/ml at a signal-to-noise ratio of 3. To summarize, the present work provides a low-cost, fast response time, highly sensitive and easy-to-prepare method for the determination of antigen in biological products.

Antibodies, Viral↗
PubMed2004

Heme oxygenase-1 expression in human lungs with cystic fibrosis and cytoprotective effects against Pseudomonas aeruginosa in vitro.

Inflammation and oxidative stress play important roles in cystic fibrosis (CF) lung disease. Inflammatory/oxidant-mediated induction of heme oxygenase-1 (HO-1) is believed to be a cytoprotective response. This study examined HO-1 expression in lung samples from patients with CF using immunohistochemistry and quantitative reverse transcription-polymerase chain reaction. In addition, we evaluated myeloperoxidase staining as a marker of acute inflammation and potentially an increase in oxidant stress and Prussian blue and ferritin staining to assess iron status of the lung. Macrophage HO-1 staining was increased in diseased lungs as compared with normal control subjects and correlated with myeloperoxidase staining. Quantitative reverse transcription-polymerase chain reaction further supported an increase in HO-1 expression in CF lung disease. Although iron staining was minimal, ferritin staining was increased in diseased lungs in concert with HO-1 staining. To determine whether HO-1 induction was cytoprotective, we evaluated a CF airway epithelial cell line, IB3.1, in response to Pseudomonas aeruginosa-induced injury/apoptosis in cells overexpressing HO-1 by either transient or stable transfection of pcDNA3.1/HO-1 construct. Overexpression of HO-1 resulted in protection against P. aeruginosa-induced injury/apoptosis. This suggests that the induction of HO-1 in patients with CF is a cytoprotective event and that augmenting its expression is a potential therapy against bacterial injury.

Apoptosis↗
PubMed2004

Multilayer assembly of Prussian blue nanoclusters and enzyme-immobilized poly(toluidine blue) films and its application in glucose biosensor construction.

A multilayered glucose biosensor via sequential deposition of Prussian blue (PB) nanoclusters and enzyme-immobilized poly(toluidine blue) films was constructed on a bare Au electrode using electrochemical methods. The whole configuration of the present biosensor can be considered as an integration of several independent hydrogen peroxide sensing elements. In each sensing element, the poly(toluidine blue) film functioned as both the supporting matrix for the glucose oxidase immobilization and the inhibitor for the diffusion of interferences, such as ascorbic acid and uric acid. Meanwhile, the deposited Prussian blue nanocluster layers acts as a catalyst for the electrochemical reduction of hydrogen peroxide formed from enzymatic reaction. Performance of the whole multilayer configuration can be tailored by artificially arranging the sensing elements assembled on the electrode. Under optimal conditions, the biosensors exhibit a linear relationship in the range of 1 x 10(-4) to 1 x 10(-2) mol/L with the detection limit down to 10(-5) mol/L. A rapid response for glucose could be achieved in less than 3 s. For 1 mM glucose, 0.5 mM acetaminophen, 0.2 mM uric acid, and 0.1 mM ascorbic acid have no obvious interferences (<5%) for glucose detection at an optimized detection potential. The present multilayered glucose biosensor with a high selectivity and sensitivity is promising for practical applications.

Biosensing Techniques↗
PubMed2004

Prussian blue modified amperometric FIA biosensor: one-step immunoassay for alpha-fetoprotein.

The aim of this study was to develop a rapid method to measure alpha-fetoprotein (AFP) in human serum by use of one-step sandwich enzyme-linked immunosorbent assay (ELISA)-based immunobiosensor with disposable screen-printed carbon electrode technology. Prussian blue (PB) was deposited using cyclic voltammetry (CV) on the surface of electrode to catalyze H202 from the reaction of glucose oxidase. It took only about 30 min to complete the whole experimental procedure through flow injection analysis (FIA). A detection range obtained is in the range from 5 to 500 ng/ml AFP. This detection seems to be quick, reliable and practical.

Biosensing Techniques↗
PubMed2006

Enhanced charge transport and incorporation of redox mediators in layer-by-layer films containing PAMAM-encapsulated gold nanoparticles.

In this work, we exploit the molecular engineering capability of the layer-by-layer (LbL) method to immobilize layers of gold nanoparticles on indium tin oxide (ITO) substrates, which exhibit enhanced charge transfer and may incorporate mediating redox substances. Polyamidoamine (PAMAM generation 4) dendrimers were used as template/stabilizers for Au nanoparticle growth, with PAMAM-Au nanoparticles serving as cationic polyelectrolytes to produce LbL films with poly(vinylsulfonic acid) (PVS). The cyclic voltammetry (CV) of ITO-PVS/PAMAM-Au electrodes in sulfuric acid presented a redox pair attributed to Au surface oxide formation. The maximum kinetics adsorption is first-order, 95% of the current being achieved after only 5 min of adsorption. Electron hopping can be considered as the charge transport mechanism between the PVS/PAMAM-Au layers within the LbL films. This charge transport was faster than that for nonmodified electrodes, shown by employing hexacyanoferrate(III) as the surface reaction marker. Because the enhanced charge transport may be exploited in biosensors requiring redox mediators, we demonstrate the formation of Prussian blue (PB) around the Au nanoparticles as a proof of principle. PAMAM-Au@PB could be easily prepared by electrodeposition, following the ITO-PVS/ PAMAM-Au LbL film preparation procedure. Furthermore, the coverage of Au nanoparticles by PB may be controlled by monitoring the oxidation current.

Journal Article↗
PubMedDate not supplied

Visualization of the barrier layer through iontophoresis of ferric ions.

The barrier layer in the intact epidermis of pig skin effectively limits the penetration of ferric ions even under conditions of iontophoresis. This was microscopically demonstrated using a ferric ion salt in conjunction with a soluble ferrocyanide to produce a Prussian blue ferric ferrocyanide precipitate. The effectiveness of various skin preparation techniques in breaking through the epidermal barrier layer was examined, utilizing this chemical reaction to stain the skin.

Animals↗
PubMed2006

Mechanism for interplay between electron and ionic fluxes in KhFek[Fe(CN)6]l.mH2O compounds.

This paper develops a framework for the interpretation of ionic insertion/deinsertion reactions in an aqueous environment taking place in transition-metal hexacyanoferrates of the general formula K(h)[Fe(2+) (CN)(6)](l).mH(2)O, also called Prussian Blue. Three different processes were fully separated in the electrochemistry of these films. It was clearly identified that one of these electrochemical processes involves the insertion/deinsertion of H(3)O(+) (hydrated protons) through the channels of the K(h)[Fe(2+) (CN)(6)](l).mH(2)O structure to reach the film electroneutrality during the electron transfer between Everitt's Salt and Prussian Blue. The other electrochemical processes involve K(+) or H(+) (proton) exchange through the water crystalline structure existing in the channels of the K(h)[Fe(2+)(CN)(6)](l).mH(2)O structure.

Journal Article↗
PubMed2002

Liver pathology in compound heterozygous patients for hemochromatosis mutations.

BACKGROUND: While hepatic pathology of homozygous carriers of the C282Y mutation of the HFE haemochromatosis gene is well defined, the impact of the C282Y/H63D compound heterozygous carrier state is unknown. AIMS: To evaluate the range of hepatic pathology in C282Y/H63D compound heterozygous patients. PATIENTS: 25 C282Y/H63D compound heterozygous patients with and without known underlying liver disease underwent liver biopsies for evaluation or abnormal liver tests. Eleven cadaveric liver donors with HFE wild type served as controls. METHODS: Mutations in the HFE gene were detected by polyacrylamide gel electrophoresis (PAGE) separation of digested polymerase chain reaction (PCR)-amplificates. The extent of light microscopic changes of liver architecture were studied on haematoxylin, eosin (H. E.) stains. In addition, the extent and the distribution of iron deposition was graded on Prussian blue-stained sections and hepatic iron was quantified by atom absorption spectroscopy. Serum ferritin concentration and the transferrin saturation index were measured using routine laboratory methods. RESULTS: Patients without underlying liver disease (n = 15): Hepatic inflammation was seen in only 8% but fibrosis was found in 36% of compound heterozygous patients. Eighty six percent of those patients had stainable iron predominantly found in Rappaport's zone 1 and 2, but all had a liver iron-index < 1.9. Transferrin saturation was found elevated in 36% of compound heterozygous patients. Patients with liver fibrosis showed significantly higher ferritin levels than patients without liver fibrosis (1110 ng/mL versus 307 ng/mL, p < 0.05). Patients with underlying disease (n = 10): In compound heterozygous patients, 77% had hepatic inflammation and 88% fibrosis. Stainable iron (44%) was less frequently found than in patients without underlying liver disease. Hepatic iron-index in patients with underlying liver disease was always below 1.17; transferrin saturation was elevated in only 22% of the compound heterozygous patients. Histologic hepatic iron-index was significantly lower in patients with underlying disease (median 0.047) as compared to patients without underlying liver disease (median 0.274, P < 0.05). CONCLUSIONS: The underlying liver disease determines the extent of hepatic pathology seen in livers of compound heterozygous patients. However, considerable histologic fibrosis can also be found in compound heterozygous patients without underlying liver disease.

Adolescent↗
PubMed2002

Co(3)[Co(CN)(5)](2): a microporous magnet with an ordering temperature of 38 K.

The reaction between [Co(H2O)6]2+ and [Co(CN)5]3- in deoxygenated water yields a dark blue solid of composition Co3[Co(CN)5]2.8H2O (1). X-ray powder diffraction data indicate a cubic Prussian blue-type framework, wherein the hexacyanometalate positions have only a two-thirds occupancy of square-pyramidal [Co(CN)5]3- units. Upon dehydration, the compound retains crystallinity and exhibits a Type I dinitrogen sorption isotherm, characteristic of a microporous solid. Magnetic measurements show 1 to behave as a ferrimagnet with an ordering temperature of 48 K, which is reduced to 38 K in the dehydrated solid. At 5 K, both 1 and dehydrated 1 exhibit magnetic hysteresis with a coercive field of 1160 G (the highest value yet reported for a cubic Prussian blue analogue) and remnant magnetizations of 1540 and 745 cm3G/mol, respectively. Thus, dehydrated 1 represents the first compound for which microporosity and long-range magnetic ordering have been demonstrated to coexist.

Journal Article↗
PubMed1991

Iron as a possible aggravating factor for osteopathy in itai-itai disease, a disease associated with chronic cadmium intoxication.

Itai-itai disease is thought to be the result of chronic cadmium (Cd) intoxication. We examined 23 autopsy cases of itai-itai disease and 18 cases of sudden death as controls. Urine and blood samples from 10 patients were collected before they died and revealed the presence of severe anemia and renal tubular injuries. Undecalcified sections of iliac bone were stained with Aluminon reagent, and ammonium salt of aurintricarboxylic acid, and Prussian blue reagent in all cases of itai-itai disease. These two reagents reacted at the same mineralization fronts. X-ray microanalysis revealed the presence of iron at mineralization fronts in itai-itai disease. Five patients showed evidence of hemosiderosis in the liver, spleen, and pancreas, probably as a result of post transfusion iron overload. Renal calculi and calcified aortic walls were also stained with Prussian blue reagent in several patients. Neither ferritin nor transferrin were visualized at mineralization fronts in itai-itai disease by immunohistochemical staining. These results suggest that iron is bound to calcium or to calcium phosphate by a physicochemical reaction. A marked osteomalacia was observed in 10 cases of itai-itai disease by histomorphometry. Regression analyses of data from cases of itai-itai disease suggested that an Aluminon-positive metal inhibited mineralization and that renal tubules were injured. Since bone Cd levels were increased in itai-itai disease, it is likely that renal tubules were injured by exposure to Cd. Therefore, stainable bone iron is another possible aggravating factor for osteopathy in itai-itai disease, and a synergistic effect between iron and Cd on mineralization is proposed.

Aged↗
PubMed2000

Pulmonary edema in fatal heroin overdose: immunohistological investigations with IgE, collagen IV and laminin - no increase of defects of alveolar-capillary membranes.

Pulmonary edema complicating heroin overdosage is a well recognized entity and regarded as the major mechanism contributing to death in heroin addicts. It's pathogenesis is unknown, several mechanisms are discussed: hypoxia-induced increase of pulmonary capillary permeability, depressed myocardial contractility, centrally induced respiratory depression, primary toxic effects on the alveolar capillaries and acute anaphylactic shock. The present study included opiate-related deaths (n=23) and a control group of sudden cardiovascular deaths (n=12) to verify the hypothesis, that defects of the alveolar capillary membranes and/or an acute anaphylactic reaction leads to pulmonary congestion, edema and hemorrhages. Lung specimens were obtained from these 35 autopsies of persons autopsied in the Institute of Forensic Medicine, University of Bonn, in 1997 and 1998. All specimens were examined with hematoxylin-eosin, prussian blue and investigated with immunohistological methods using primary antibodies against collagen IV, laminin and IgE. Defects of the basal laminae of the alveoli were found, demonstrated by laminin and collagen IV, and the number of IgE-positive cells was counted in both groups. There was an increased but not significant number of IgE-positive cells in the heroin-group and defects of the epithelial and endothelial basal laminae were found in both groups without significant differences.

Anaphylaxis↗
PubMed1995

Ringed sideroblasts: a frequent observation after bone marrow transplantation.

Dyserythropoiesis after bone marrow transplantation is common, but the presence of ringed sideroblasts (RS) has not been evaluated fully. To examine for RS, a combined silver and Perls' Prussian blue stain, shown previously to be more sensitive for detecting RS than Perls' Prussian blue stain alone, was used on post-transplant marrow aspirate sections from 39 patients who received marrow transplants (allogeneic, 28; autologous, 11) for a variety of disorders. Marrow aspirate sections were available for comparison from 11 of these patients before any treatment as well as from five patients with normal marrows and normal peripheral blood cell counts. Aspirates were not performed on donor marrows. By the modified silver stain, RS were present in 34 (87%) patients whose marrows were sampled 0.5 to 39 (median, 1.5) months post-transplant including 10 of 11 patients with autologous transplants (no graft versus host disease prophylaxis). In contrast, seven of 36 (19%) of these marrows contained RS when stained with Perls' reaction alone. Only one of 11 pretransplant marrows and none of five normal marrows contained RS when stained by either method. These results demonstrate that RS are present in most post-transplant marrows even beyond the usual period of reconstitution (28 days), and this finding can be included among the features of dyserythropoiesis seen after transplantation. RS apparently are not related to pretransplant pathology or post-transplant therapy. This study also confirms previous observations that modified silver stains are more sensitive for detecting RS than Perls' Prussian blue stain.

Adolescent↗
PubMed2003

Nanoparticles of Prussian blue ferritin: a new route for obtaining nanomaterials.

The dissociation of apoferritin into subunits at pH 2 followed by its re-formation at pH 8.5 in the presence of hexacyanoferrate(III) gave rise to a solution containing hexacyanoferrate(III) trapped within the apoferritin and hexacyanoferrate(III) outside it. The addition of Fe(II) to the dialyzed solution resulted in the appearance of the characteristic Prussian blue color. The UV-vis spectrum of this solution showed a broad band centered at 710 nm, and the IR spectrum contained a broad-medium band at 2083 cm(-1). Both features are consistent with the charge-transfer band and the C[bond]N stretching mode in the Fe(II)[bond]CN[bond]Fe(III) fragment of PB. TEM images of the obtained Prussian blue solution showed discrete spherical electron dense iron particles with an average size of about 5 nm. This represents a new route for preparing metallic nanoparticles that offers control over the size and protection against aggregation. Moreover, the fact that the particles are obtained by reaction of hexacyanoferrate(III) and iron(II) building blocks opens up the possibility of obtaining not only homo- but also heterobimetallic nanoparticles.

Journal Article↗
PubMed2005

Chronocoulometric study of the electrochemistry of Prussian blue.

During the electrochemical oxidation of Prussian blue (PB) to Prussian yellow (PY), an electrocatalytic oxygen production proceeds at the electrode when aqueous electrolyte solutions are used. The formed oxygen is scavenged by the PY, probably by absorption, and it is consumed during the electrochemical reduction of PY to PB by a heterogeneous chemical reaction of PB with oxygen to PY and hydrogen peroxide. Because of this catalytic regeneration of PY, it is impossible to determine the amount of low-spin iron by chronocoulometry using a potential program in which PB is first oxidized to PY and then the charge is measured to reduce PY to PB. The latter charge is biased by the electrocatalytic PY regeneration.

Journal Article↗
PubMed1999

A convenient microscale colorimetric method for terminal galactose on immunoglobulins.

A new approach for quantitative determination of terminal galactose (Gal) residues of immunoglobulins was developed by combining exoglycosidase digestion with the classical colorimetric estimation of reducing sugars. The ferricyanide colorimetric method was modified to increase the stability of the chromophore (Prussian blue) and adapted to determine the amount of terminal Gal residues present in immunoglobulins. The method involves the release of covalently bound Gal from immunoglobulins by Diplococcus pneumoniae beta-D-galactosidase (specific for beta(1,4) linked galactose), removal of the glycoprotein and enzyme from the reaction mixture by heat denaturation or ethanol precipitation, followed by colorimetric measurement of the released sugar using the ferricyanide assay. The ferricyanide method was modified to enhance the solubility and stability of the chromophore by increasing the concentration of aqueous sulfuric acid and sodium dodecyl sulfate (SDS). The linear range of the modified method was from approximately 11 to 111 microM Gal. Typical variation in assay results was on the order of 5%. Using the modified method, the terminal Gal content of a recombinant chimeric monoclonal antibody (anti-CD20, rIgG) expressed in Chinese hamster ovary (CHO) cells was determined and evaluated for batch-to-batch consistency. The method was used to optimize pH, time, temperature, and enzyme concentration for beta-galactosidase digestion for maximal release of terminal Gal residues from rIgG.

Animals↗
PubMedDate not supplied

Abundance of siderophages in sputum: indicator of an adverse lung reaction to air pollution.

OBJECTIVE: To investigate the lung response to traffic-related air pollution by enumerating hemosiderin-laden alveolar macrophages (AM) in sputum. STUDY DESIGN: Sputum samples were collected from 103 urban adult males from Calcutta chronically exposed to automobile exhaust. Forty-nine rural individuals served as controls. AM were identified by nonspecific esterase staining. Perl's Prussian blue technique was employed for the detection of hemosiderin-laden AM (siderophages). RESULTS: The urban group, consisting of 31 traffic officers, 25 automobile service station workers and 47 street hawkers, had seven times more AM in their sputum than did the matched controls. Besides, a remarkable rise (27-fold) in the number of siderophages in sputum was observed in urban individuals. Smoking further elevated the AM count and number of siderophages. CONCLUSION: Abundant siderophages in the urban group may indicate the toxic effect of airborne pollutants on the lung, leading to phagocytosis of destroyed cells, including erythrocytes, and accumulation of iron in AM. Enumeration of siderophages in sputum appears to be a simple, noninvasive, inexpensive cytochemical technique well suited to preliminary assessment of the adverse effects of air pollution on the lungs in large, population-based studies, especially in developing countries.

Adult↗
PubMed2006

Pressure-induced sequential magnetic pole inversion and antiferromagnetic-ferromagnetic crossover in a trimetallic prussian blue analogue.

The flexibility of the structure of Prussian blue analogues and its ability to incorporate a variety of competing magnetic interactions have allowed the design of mixed ferro-ferrimagnets, which span the whole spectrum of magnetic behavior, including the rare phenomenon of magnetization reversal in response to a change in temperature. Hydrostatic pressure is used here to induce multiple reversals of the direction of the spontaneous magnetization in the trimetallic Prussian blue analogue, Rb0.64Ni0.31Mn0.87[Fe(CN)6].2.8H2O. Remarkably, the magnetic response is extremely sensitive to pressure, and the magnetization flips from positive to negative and back to positive in a very narrow pressure range (0 < P < 0.6 kbar). A further increase in pressure to 4.0 kbar induces an internal redox reaction, and the magnetic order switches from ferrimagnetic to bulk ferromagnetism.

Journal Article↗