Fertilizer Materials, Preparation and Characterization of Some Calcium Pyrophosphates

Brown, Earl H.; Lehr, James R.; Smith, James P.; Frazier, A. W.

doi:10.1021/jf60127a020

Cited by 79 publications

(66 citation statements)

References 5 publications

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“…Crystal-induced inflammation is a dose-related phenomenon (1 4,15), and amounts of synthetic MSU or CPPD crystals in the milligram range are generally injected to induce clinically apparent inflammatory signs and symptoms. It is interesting that the concentrations of HA crystals estimated by the present study are in the microgram range, as is true for CPPD crystals (1 2).…”

Section: Discussionmentioning

confidence: 99%

Identification of hydroxyapatite crystals in synovial fluid

Halverson

McCarty

1979

Arthritis & Rheumatism

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A semiquantitative technique employing ("C) ethane-1-hydroxy 1, -1-diphosphonate (EHDP) binding has been used to detect crystals, presumably hydroxyapatite, in human synovial fluid samples which were handled to prevent the formation of artifactual mineral phase. Binding material was found in 29% of noninflammatory and in none of inflammatory joint fluids. Nuclide binding material was strongly correlated with the presence of CPPD crystals and with radiographic evidence of cartilaginous degeneration.Several groups of investigators have reported finding hydroxyapatite (HA) crystals in synovial fluid. Dieppe and colleagues reported a series of 5 synovial fluids from patients with osteoarthritis; each contained small crystalline particles by scanning and transmission electron microscopy that on energy-dispersive analysis with an electron probe showed a calcium/phosphorus (Ca/P) molar ratio of 1.66, typical of HA (1). Using

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Section: Discussionmentioning

confidence: 99%

Identification of hydroxyapatite crystals in synovial fluid

Halverson

McCarty

1979

Arthritis & Rheumatism

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“…In addition, for experiments to detect cytochrome C reduction by crystals, a different MSU preparation that had an average length of 7 p was also used. Calcium pyrophosphate dihydrate (CPPD) crystals were prepared by the method of Brown et al (7). The length of the average CPPD crystal was 8p.…”

Section: Methodsmentioning

confidence: 99%

Stimulation of the respiratory burst in human neutrophils by crystal phagocytosis

Simchowitz

Atkinson

Spilberg

1982

Arthritis & Rheumatism

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Exposure to monosodium urate crystals (MSU) stimulated the respiratory burst of human neutrophils as measured by increased O2 consumption and the generation of superoxide radicals (027. From the comparison of data derived from nitroblue tetrazolium and cytochrome C reduction (two methods of detecting 0 z r release), it appears that OZT production in response to MSU may be compartmentalized, i.e., occur predominantly in the intracellular space. After exposure to MSU, neutrophils from patients with chronic granulomatous disease lost viability at the normal rate; thus products of the respiratory burst are not likely to be responsible for cell death.The oxidative killing mechanisms of phagocytic cells have been shown to serve a fundamental role in the host defenses against microorganisms (1). Central to this scheme is the generation of superoxide ( 0 2 radicals formed by the univalent reduction of molecular oxygen (2,3). Superoxide and its reaction products hydrogen peroxide, hydroxyl radical, and singlet oxygen may contribute to phagocytic bactericidal capacity (1-3) and mediate cytotoxicity in vitro (43). Activation of the 02T generating system of the neutrophil has been shown to occur after phagocytosis of particulate stimuli [such as bacteria, latex spheres, and opsonized zymosan (2,3)], as well as after exposure of the cells to such diverse soluble stimuli as chemotactic factors, immune complexes, ionophores, lectins, and detergents (2,3). In this study, we compared the respiratory burst of cells from normal individuals and from chronic granulomatous disease (CGD) patients after stimulation by monosodium urate crystals (MSU). This crystal model permitted us to test hypotheses about the intracellular release of 02-and its potential cytotoxic role. MATERIALS AND METHODSMedium. The medium used throughout this study was a modified Hanks' balanced salt solution supplemented with glucose (1 mg/ml) and bovine serum albumin (1 mg/ml), pH 7.40.Neutrophils. Human peripheral neutrophils were isolated from heparinized blood by sequential dextran sedimentation and Ficoll-Hypaque gradient centrifugation, as previously described (4).In addition to studies performed with cells from normal donors, neutrophils were obtained from 2 male patients with CGD. The diagnosis in both patients (ages 8 and 10) was based on the recurrence of pyogenic infections since early childhood and the absence of all components of respiratory burst activity when neutrophils were subjected to a variety of stimulating agents (3).Reagents and chemicals. The following reagents were purchased from Sigma Chemical Company: cytochalasin B,

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“…Brown et al 22 have reported a synthetic route to an amorphous calcium pyrophosphate, but with high levels of sodium contamination. Here, we therefore report the synthesis and characterisation of a series of amorphous pyrophosphate phases of O. Syntheses were also attempted where the metal salt solutions were slowly added to a vigorously stirred potassium pyrophosphate solution using the same concentrations as stated previously.…”

Section: Introductionmentioning

confidence: 99%

Enhanced stability and local structure in biologically relevant amorphous materials containing pyrophosphate

et al. 2011

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There is increasing evidence that amorphous inorganic materials play a key role in biomineralisation in many organisms, however the inherent instability of synthetic analogues in the absence of the complex in vivo matrix limits their study and clinical exploitation. To address this, we report here an approach that enhances long-term stability to >1 year of biologically relevant amorphous metal phosphates, in the absence of any complex stabilisers, by utilising pyrophosphates (P 2 O 7 4À ); species themselves ubiquitous in vivo. Ambient temperature precipitation reactions were employed to synthesise amorphous Ca 2 P 2 O 7 .nH 2 O and Sr 2 P 2 O 7 .nH 2 O (3.8 < n < 4.2) and their stability and structure were investigated. Pair distribution functions (PDF) derived from synchrotron X-ray data indicated a lack of structural order beyond $8 A in both phases, with this local order found to resemble crystalline analogues. Further studies, including 1 H and 31 P solid state NMR, suggest the unusually high stability of these purely inorganic amorphous phases is partly due to disorder in the P-O-P bond angles within the P 2 O 7 units, which impede crystallization, and to water molecules, which are involved in H-bonds of various strengths within the structures and hamper the formation of an ordered network. In situ high temperature powder X-ray diffraction data indicated that the amorphous nature of both phases surprisingly persisted to $450 C. Further NMR and TGA studies found that above ambient temperature some water molecules reacted with P 2 O 7 anions, leading to the hydrolysis of some P-O-P linkages and the formation of HPO 4 2À anions within the amorphous matrix. The latter anions then recombined into P 2 O 7 ions at higher temperatures prior to crystallization. Together, these findings provide important new materials with unexplored potential for enzyme-assisted resorption and establish factors crucial to isolate further stable amorphous inorganic materials. IntroductionA growing awareness of the existence and potential of amorphous inorganic materials has led to a rapid increase in their study in recent years. Often previously neglected or undetected as a consequence of their lack of long-range structural order and relative instability, amorphous inorganic materials are now more readily evident, partly through the continuing development of techniques sensitive to local order, such as magic angle spinning (MAS) solid state NMR and atomic pair distribution functions. Of particular interest has been the discovery of their prevalence in a diverse range of biological systems, 1-8 where it appears organisms exploit their unique properties in a number of processes.Amorphous calcium carbonate (ACC) is one of the most widely studied amorphous materials in nature, 1,2 with numerous studies on marine creatures, 9 where ACC has been shown to be a transient precursor to hard external shell formation. In effect, the highly unstable and soluble ACC is used as a reactive store of calcium and carbonate ions whose transformation in...

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Fertilizer Materials, Preparation and Characterization of Some Calcium Pyrophosphates

Abstract: IV. Morphological and Optical Properties of Crystalline Pyrophosphates Refractive Crystal System, Class, and Habit Indices

Cited by 79 publications

References 5 publications

Identification of hydroxyapatite crystals in synovial fluid

Identification of hydroxyapatite crystals in synovial fluid

Stimulation of the respiratory burst in human neutrophils by crystal phagocytosis

Enhanced stability and local structure in biologically relevant amorphous materials containing pyrophosphate

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