Mixture Of Citrate Research Articles

Soluble P-selectin assay: importance of correct anticoagulant choice

P-selectin is stored preformed in the-granules of platelets. Previous studies show-thromboglobulin, also stored in-granules can be readily released from platelets during the processing of whole blood. This artefactual release was rectified by using combination of various anti-platelet and anticoagulant compounds placed in the collecting tube. We investigated the levels of sP-selectin from 40 volunteers, comparing two anticoagulants, tri-sodium citrate, CTAD (a mixture of sodium citrate and citric acid, theophylline, adenosine and dipyridamole) plus iloprost and serum. Iloprost, a stable prostacyclin analogue, is a potent anti-platelet agent. We found significantly lower levels of sP-selectin ( P < 0.0001, paired t-test ) measured from blood collected into CTAD and iloprost compared to levels measured from either citrated plasma or serum. We suggest that plasma levels obtained from the blood collected into a CTAD tube containing iloprost are likely to more accurately reflect the true levels of circulating sP-selectin than those obtained when test-tube activation of platelets is allowed to continue in vitro . </abs>

Preparation of a Macrocyclic Polyamine-bonded Column for the Electrophoretic Separation of Inorganic and Organic Anions

A 24-membered macrocyclic polyamine based on the propylene-1,3-diamine unit that was able to form polyprotonated, highly charged species in the neutral pH region was selected to act as an anion complexone. It was synthesized and incorporated in a fused-silica capillary for the electrophoretic separation of inorganic and organic anions. This complexing agent can selectively modulate the mobility of anions by forming anion complexes with varying degrees of stability. Parameters which influence capillary electrophoretic separations such as applied voltage, choice of electrolyte anion, electrolyte pH and electrolyte concentration were investigated. A mixture of thiosulfate, chloride, sulfate, selenate, perchlorate, tungstate, carbonate and selenite could be separated in 5 mM sodium chromate at pH 10.0 within 13 min. A mixture of bromide, oxalate, malate, citrate, tartrate, maleate, succinate, acetate, lactate, butyrate, p-hydroxybenzoate, salicylate and octanesulfonate could be separated in 10 mM phthalate at pH 5.0 within 11 mins. Under the same conditions, even geometric isomers or mixtures of polycarboxylates and polyphosphates, such as ATP and ADP, could be well separated. The experimental results indicated that incorporating the chelating functional group in the inner wall of the capillary markedly enhances the selectivity of the system.

Soluble P-selectin assay: importance of correct anticoagulant choice

P-selectin is stored preformed in the α-granules of platelets. Previous studies show ß-thromboglobulin, also stored in α-granules can be readily released from platelets during the processing of whole blood. This artefactual release was rectified by using combination of various anti-platelet and anticoagulant compounds placed in the collecting tube. We investigated the levels of sP-selectin from 40 volunteers, comparing two anticoagulants, tri-sodium citrate, CTAD (a mixture of sodium citrate and citric acid, theophylline, adenosine and dipyridamole) plus iloprost and serum. Iloprost, a stable prostacyclin analogue, is a potent anti-platelet agent. We found significantly lower levels of sP-selectin (P< 0.0001, paired t-test) measured from blood collected into CTAD and iloprost compared to levels measured from either citrated plasma or serum. We suggest that plasma levels obtained from the blood collected into a CTAD tube containing iloprost are likely to more accurately reflect the true levels of circulating sP-selectin than those obtained when test-tube activation of platelets is allowed to continue in vitro.

OSMOTIC DEHYDRATION OF PEAS: I. INFLUENCE OF PROCESS VARIABLES ON MASS TRANSFER

Osmotic dehydration of uniformly sized peas at 30C was studied using different solutions of sucrose, sodium citrate and sucrose+citrate mixture. The influence of various factors such as solution concentration and composition and the effect of agitation on the mass transfer mechanism was investigated. It was shown that the rate of water loss in the sample was increased by increasing concentration of osmosis solution and agitation. The most effective osmotic dehydration was obtained in sucrose+citrate mixed solutions of 60% total solids level for which a dehydration model was proposed. The apparent diffusion coefficient of water Da was determined using the dehydration model. The values of Da were found to be in the range 9.10 ± 10−11-7.63 ± 10−10 m2/s.

Comparison of various forms of palladium used as chemical modifiers for the determination of selenium by electrothermal atomic absorption spectrometry

The efficiencies of various chemical modifiers based on palladium for the determination of selenium in the presence of sodium chloride by electrothermal atomic absorption spectrometry were investigated. Palladium nitrate proved to be superior to palladium chloride for selenium only in pure solutions. In the presence of a chloride matrix, these two chemical modifiers are of similar and rather low effectiveness, whereas ammonium dioxalatopalladate(II), colloidal palladium and a mixture of palladium nitrate and diammonium hydrogen citrate were found to be more effective. Using these latter modifiers, the chloride matrix does not prevent the formation of metallic palladium at relatively low temperatures. However, maximum modification efficiency was obtained with prereduced (at 1000 °C) palladium. Using this form of palladium as a chemical modifier, up to 330 µg of sodium chloride do not interfere in the determination of 2 ng of selenium. The relatively low effectiveness of colloidal palladium, which was stabilized with a polymer compound, could be explained by the formation and partial loss of volatile organoselenium compounds. Also, the surface of colloidal palladium is screened off by the polymer causing a rather low accessibility for selenium species.

Effect of heparin anticoagulation on neutrophil adhesion molecules and release of IL8: C3 is not essential

To examine the role of heparin in modulating neutrophil activation and release of cytokine.Up-regulation of CD11b, down-regulation of L-selectin on neutrophil cell surface and release of IL8 occur in response to extracorporeal circulation (ECC) and were proposed to cause leakage of the capillaries in patients.In a series of experiments, we examined the effect of heparin (4 U/ml) comparing it with ethylenediamine tetra-acetate (EDTA, 1.5 mg/ml) and citrate mixture (100 microliters/ml), heparin dose-response, IL8 (human recombinant IL8) dose-response and protamine (80 micrograms/ml) neutralisation of heparin (4 U/ml) using donor blood (total of 38). The role of complement component type 3 (C3) was tested. Neutrophils from a patient with complete C3 deficiency were stimulated by using heparin and cobra venom factor (10 micrograms/ml) and compared with controls (n = 5). CD11b and L-selectin expressions were assayed immediately and serially up to 120 min using immune fluorescence and flow cytometry. Serum concentrations of IL8 were determined by using enzyme-linked immunosorbent assay.The medians of up-regulation of CD11b were 540.2 (range 235.2-653.3) for heparin vs. 186.5 (55.7-207.1) for EDTA and 192.5 (69.2-263.8) for citrate mixture, P < 0.01. The medians of down-regulation of L-selectin were 79 (32-192) for heparin vs. 18.4 (0-188) for EDTA and 36.2 (7.4-135) for citrate mixture, P < 0.05. Up-regulation of CD11b, down-regulation of L-s and release of IL8 were inversely related to heparin concentration (r = 0.87, P < 0.05). Serum concentration of IL8 had a direct relationship to the changes in CD11b and L-selectin expression (r = 0.92). Heparin-protamine complex was less stimulant to expression of CD11b and L-selectin than heparin or protamine (P < 0.05). In blood samples from C3-deficient patients, heparin and cobra venom factor caused up-regulation of CD11b and down-regulation of L-selectin similar to that of controls (P > 0.05).Heparin stimulates up-regulation of neutrophil adhesion molecules CD11b, down-regulation of L-selectin and release of IL8. These effects are inversely related to heparin concentration and are independent of C3 activation. IL8 has a direct relationship to activation of neutrophil adhesion molecules. Increasing heparin dosage reduces neutrophil activation and may reduce the morbidity of patients.

Effect of iron as a new type of phosphate binder in hemodialysis patients

Hyperphosphatemia is one of the major problems requiring management in the majority of hemodialysis patients and they require phosphate-binding agents to control the hyperphosphatemia. Aluminum hydroxide and calcium compounds are used currently as phosphate-binding agents to treat hyperphosphatemia, but these compounds can cause undesirable side effects. Therefore, the development of new phosphate-binding agents is imperative. It is well known that oral and intravenous administration of iron causes hypophosphatemia. We hypothesized that this side effect of iron may be beneficial for the treatment of hyperphosphatemia in hemodialysis patients. Consequently, we conducted a fundamental and clinical investigation of the effects of iron administration. Membrane permeability of phosphorus in a mixture of sodium ferrous citrate and dessicated aluminium hydroxide in the presence of hydrogenated lecithin as a phosporic compound was examined. Fifteen patients undergoing hemodialysis were treated with 150 mg of sodium ferrous citrate given orally for eight weeks. The permeability of the filtering membrane to phosphorus decreased in accordance with the dosage of sodium ferrous citrate and dessicated aluminum hydroxide. The degree of phosphate-binding effect of sodium ferrous citrate was larger than that of dessicated aluminum hydroxide. Serum phosphorus decreased significantly during the experiment. These results suggest that the oral administration of sodium ferrous citrate as a new phosphate binder is a useful therapeutic method for hemodialysis in patients with hyperphosphatemia.

Effect of Standardized Mixture of Potassium and Sodium Citrate and Citric Acid (Uralyt-U) on the Correction of Postoperative Acidosis in Patients Who Underwent Ureterosigmoidostomy

Effect of Standardized Mixture of Potassium and Sodium Citrate and Citric Acid (Uralyt-U) on the Correction of Postoperative Acidosis in Patients Who Underwent Ureterosigmoidostomy

Different clotting mechanisms of Bothrops jararaca snake venom on human and rabbit plasmas

M. L. Santoro and I. S. Sano-Martins. Different clotting mechanisms of Bothrops jararaca snake venom on human and rabbit plasmas. Toxicon 31, 733–742, 1993.— Bothrops jararaca venom is approximately 3.5 times more effective at coagulating rabbit plasma than human plasma. To investigate this difference B. jararaca venom was treated with several enzymatic inhibitors and the minimum coagulant dose was determined both on plasma anticoagulated with sodium citrate or a mixture of sodium citrate and heparin, and on fibrinogen (both human and rabbit). On human plasma, the thrombin-like component of the venom accounted for c. 60% of the coagulant activity, such activity was negligible on rabbit plasma. The venom had little clotting activity on rabbit fibrinogen. The factor II- and X-activator components could be inhibited by EDTA, EGTA and 2-mercaptoethanol, whereas the thrombin-like activity was inhibited by PMSF. These differences show that (using human plasma) B. jararaca clotting activity is mainly due to the thrombin-like component, whereas the factor II- and X-activator components are more important on rabbit plasma. The delayed action of the thrombin-like enzyme on rabbit fibrinogen may be attributed to the difference between rabbit and human fibrinopeptide A. Thus, the increased coagulant activity on rabbit plasma may be due to a faster rate of activation of factor X, V or II by snake venom enzymes.

Lack of potassium-anion interaction in diet selection by captive meadow voles

An experiment was conducted to test whether selective avoidance of high-potassium diets by captive meadow voles (Rodentia: Microtus pennsylvanicus) depends on the anions with which potassium is associated. Voles were presented simultaneously with a) low- and high-potassium diets formulated with either potassium sulfate, potassium chloride, or a mixture of potassium chloride and potassium citrate; or b) paired combinations of high-potassium diets containing different anions. In the first part of the experiment, voles preferntially selected the low-potassium diets, with the degree of selectivity virtually completely independent of the associated anion. These results confirm previous suggestions that potassium avoidance may be a component in diet selection by herbivores, especially during spring and summer. There is only weak indication that anion content affects selection of diets with fixed potassium content.

A vibrational spectroscopic study of nickel(II) citrate Ni 3(C 6H 5O 7) 2 and its aqueous solutions

A comprehensive Raman spectroscopic study of citric acid and its three anions has been made at 298 K and the four species have been characterised. From comparisons of the Raman spectra of nickel(II) citrate in the solid state and equimolar mixtures of nickel chloride and trisodium citrate in aqueous solution, it is concluded that nickel(II) citrate exists as the Ni(C 6H 5O 7) − species in aqueous solution, in confirmation of electrochemical studies on this system.

ChemInform Abstract: Preparation and Characterization of LaMn1‐xCuxO3+λ Perovskite Oxides.

AbstractThe title compounds with 0 ≤ x ≤ 1 are prepared via decomposition of an amorphous citrate mixture and characterized by XRD, XPS, and TPR.

Molybdenum cofactor negative mutants of Escherichia coli use citrate anaerobically

Anaerobically, Escherichia coli cannot grow using either glycerol or citrate as sole carbon and energy source. However, it has been reported that a mixture of glycerol and citrate will support growth. We have found that wild-type strains of E. coli K-12 do not grow on glycerol plus citrate anaerobically. However, growth eventually occurs due to the frequent appearance of mutants. We found that such Cit + mutants were defective in anaerobic respiration with nitrate or trimethylamine-N-oxide and were chlorate resistant (i.e. molybdenum cofactor deficient). Conversely, well characterized mutants in any of chlA, B, D, E, G and N were also able to use citrate anaerobically. No anaerobic growth differences between wild type and chl mutants were observed either with fermentable sugars or with glycerol plus fumarate or glycerol plus tartrate. Citrate lyase was induced anaerobically by citrate and repressed by glucose in both wild type strains and chl mutants. Furthermore, levels of citrate lyase, fumarate reductase, malate dehydrogenase, fumarase and alcohol dehydrogenase were similar in both types of strains under anaerobic conditions. It is conceivable that a functioning molybdenum cofactor prevents use of citrate by keeping citrate lyase in the inactive form.

Acid aspiration prophylaxis in Australian obstetric hospitals--a survey.

During 1987 a confidential survey of all hospitals in Australia providing obstetric services was undertaken to determine the antacid medications used routinely as prophylaxis against acid aspiration pneumonitis. Of the 567 hospitals surveyed, 379 (67%) responded. Of these, 243 hospitals provide an obstetric service which includes caesarean section, and 67% of these perform less than 500 deliveries per annum. Aspiration prophylaxis during labour was used in 22.4% of responding hospitals. Prior to elective caesarean section, 11.5% used no prophylaxis, and 39.4% used particulate antacids such as magnesium trisilicate mixture (33.3%) or Mylanta (6.1%). Sodium citrate mixture was the most popular therapy (37%). Results were similar in the emergency caesarean section group. The use of cimetidine or ranitidine was uncommon in all groups. Results of this survey suggest marked differences in attitudes towards acid aspiration prophylaxis between Australian and British obstetric anaesthetic practices.

Platelet volume parameters as a diagnostic tool: The influence of anticoagulation and storage conditions on platelet impedance volume

Rapid progress has been made in the design of aperture impedance cell counters, and parameters such as mean platelet volume and platelet distribution width have become routinely available to most physicians. Platelet volume is influenced by both platelet production in the bone marrow and platelet activation or sequestration in the circulation. In thrombocytopenic patients, it is often possible to differentiate between megakaryocytic and amegakaryocytic disease states on the basis of platelet volume analysis. In patients with thrombocytosis, a myeloproliferative disorder may be suspected if the platelet distribution width is high. However, the conditions of sample preparation and storage still give rise to considerable inaccuracy in the determination of platelet volume parameters. In this study, platelet impedance volume was strongly influenced by anticoagulation, storage time, and incubation temperature. Changes in platelet volume were more pronounced in whole blood than in platelet rich plasma. However, mainly large platelets were lost during the preparation of platelet rich plasma. Collecting blood directly into a mixture of citrate and low dose glutaraldehyde stabilized platelet volume for up to 2 h after venipuncture at room temperature. This method reduces platelet volume changes in vitro and is in this respect superior to the usual EDTA blood count or the use of platelet-inhibitory agents.

Use of poly(vinylpyrrolidone) and poly(vinyl alcohol) for cryoultramicrotomy.

Specimens infused with or suspended in a mixture of 10-30% poly(vinylpyrrolidone) and 2.07-1.61 M sucrose can often be more easily frozen-sectioned than those infused with sucrose alone. The pH of such a mixture can be efficiently adjusted to neutrality by using Na2CO3. Use of poly(vinylpyrrolidone) causes little or no increase in the background level of immunolabelling. Adsorption staining of ultrathin frozen sections with a mixture of uranyl acetate and poly(vinyl alcohol), i.e. a simple thin-embedding of the sections in such a mixture, produces positive staining effects that are often enough to delineate structures of many organelles. When OsO4-treated frozen sections are stained with uranyl acetate and further adsorption-stained with a mixture of lead citrate and poly(vinyl alcohol), the overall staining effects are similar to those observed in double-stained conventional sections.

The changing gastrointestinal side effect profile of non-steroidal anti-inflammatory drugs. A new approach for the prevention of a new problem.

The most serious side effects of non-steroidal anti-inflammatory drugs (NSAIDs) involve gastroduodenal perforations and massive haemorrhage. It is becoming increasingly clear, however, that it is the small intestine that bears the main brunt of NSAID-related gastrointestinal toxicity. Hence 70% of patients receiving NSAIDs in the long term have evidence of small-intestinal inflammation, and the same patients lose blood and protein as a consequence. Many patients have asymptomatic ileal dysfunction and occasionally may develop unique small-intestinal strictures necesitating surgery. The pathogenesis of the intestinal inflammation is beginning to emerge. There are data to support that an imbalance between prostaglandins and leukotrienes is important in disrupting small-intestinal integrity during drug absorption. Furthermore, a simple mixture of glucose and citrate with indomethacin appears to minimize the damage. Whether this overcomes a metabolic block caused by NSAIDs and replenishes ATP levels or acts by scavenging oxygen free radicals is unknown, but our further understanding of the mechanism may revolutionize our approach to prevention of the gastrointestinal toxicity of NSAIDs.

Effect of urea, ammonium and nitrate on foliar absorption of ferric citrate

Abstract Foliar absorption of 59Fe‐ferric citrate, with all possible combinations of urea, ammonium and nitrate, by Vigna unguiculata was studied. A significant increase in absorption was observed with a ferric citrate, urea and ammonium nitrate mixture and a ferric citrate and urea mixture. Some of the other urea containing mixtures did not exhibit enhanced absorption. The addition or subtraction of ammonium and/or nitrate was without a consistent effect None of the combinations of ferric citrate, urea, ammonium and/or nitrate greatly enhanced the re‐greening response compared to ferric citrate applied alone, nor did any of the mixtures tested cause complete re‐greening and alleviation of iron chlorosis. These results may indicate a slight, but inconsistent, benefit from adding urea to Fe foliar sprays of ferric citrate.

Correction: Potassium citrate mixture: soothing but not harmless?

Correction: Potassium citrate mixture: soothing but not harmless?

Potassium citrate mixture: soothing but not harmless?

Potassium citrate mixture: soothing but not harmless?