scholarly journals THE KINETICS OF THE PERIODATE-SCHIFF REACTION OF HUMAN LEUKOCYTE HOMOGENATES

1967 ◽  
Vol 15 (11) ◽  
pp. 646-651 ◽  
Author(s):  
INGE OLSSON ◽  
ARNE DAHLQVIST
Keyword(s):  
Periodate Oxidation ◽  
Human Leukocyte ◽  
Test Tube ◽  
High Concentration ◽  
Human Leukocytes ◽  
Considerable Fraction ◽  
Quantitative Test ◽  
Pas Reaction ◽  
Schiff Reaction ◽  
Kinetics Of

The periodate-Schiff (PAS) reaction of homogenized human leukocytes has been studied with a quantitative test tube method. The leukocytes contain glycogen, which gives a slow formation of chromogen during the periodate oxidation, and one or several more rapidly reacting, nonglycogen substances. The latter substances are quantitatively more important for the PAS reaction than glycogen. Nonglycogenic, rapidly reacting PAS-positive substances are present in a high concentration in the specific leukocyte granules. A considerable fraction of the rapidly reacting PAS-positive material in leukocyte homogenates can be extracted with lipid solvents.

Vancomycin Adsorption During in vitro Model of Hemoperfusion with HA380 Cartridge

Nephron ◽  
2021 ◽  
pp. 1-7
Author(s):  
Ilaria Godi ◽  
Anna Lorenzin ◽  
Silvia De Rosa ◽  
Gianlorenzo Golino ◽  
Maira Knust ◽  
...  
Keyword(s):  
Complete Removal ◽  
Potential Interaction ◽  
Blood Purification ◽  
Therapeutic Monitoring ◽  
High Concentration ◽  
Langmuir Isotherm Model ◽  
Vitro Model ◽  
Kinetics Of ◽  
Balanced Solution

<b><i>Introduction:</i></b> A critical point for using blood purification during sepsis may be the potential interaction with antimicrobial therapy, the mainstay of sepsis treatment. The aim of our study was to investigate the vancomycin removal during hemoperfusion (HP) using HA380 cartridge. <b><i>Methods:</i></b> This is an experimental study, in which 500 mL of solution was circulated in a closed-circuit (blood flow of 250 mL/min) simulating HP ran using HA380. Vancomycin was added to reach a through concentration or a very high concentration to evaluate the removal ratio (RR) during 120 min of HP. Comparison between blood-crystalloid solution and balanced solution was performed by using Kruskal-Wallis test. The kinetics of vancomycin removal and the adsorption isotherm were evaluated. <b><i>Results:</i></b> We found a complete removal of vancomycin at baseline through concentration of 23.0 ± 7.4 mg/L. Using extremely high concentration (baseline 777.0 ± 62.2 mg/L), RR was 90.1 ± 0.6% at 5 min and 99.2 ± 0.6% at 120 min. No difference in terms of RR was found between blood-crystalloid mixture and balanced solution. The kinetics of the vancomycin reduction followed an exponential decay. Repeated boluses (total amount of 2,000 mg) resulted in cumulative adsorption of 1,919.4 mg with RR of 96.6 ± 1.4%, regardless of the amount injected (100 vs. 500 mg). Vancomycin adsorption onto HA380 followed the Langmuir isotherm model. <b><i>Conclusions:</i></b> A considerable amount of vancomycin was rapidly removed during in vitro HP with HA380. Clinical studies are needed to determine whether this may lead to underdosing. Drug therapeutic monitoring is highly recommended when using HA380 for blood purification in patients receiving vancomycin.

scholarly journals Leaching Titaniferous Magnetite Concentrate by Alkaline Aqueous Solution

2021 ◽  
Author(s):  
Ke Guo ◽  
Shaoyan Wang ◽  
Renfeng Song ◽  
Zhiqiang Zhang
Keyword(s):  
Aqueous Solution ◽  
Alkali Concentration ◽  
Water Usage ◽  
X Ray Diffraction ◽  
High Concentration ◽  
X Ray ◽  
Iron Concentrate ◽  
Titaniferous Magnetite ◽  
Magnetite Concentrate ◽  
Kinetics Of

AbstractLeaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.

scholarly journals Κινητική της αμμωνίας εις το περιτοναϊκόν υγρόν

1968 ◽  
Author(s):  
Αναστάσιος Εμμανουήλ
Keyword(s):  
Ascitic Fluid ◽  
Peritoneal Fluid ◽  
Ammonium Citrate ◽  
Blood Ammonia ◽  
High Concentration ◽  
Group 2 ◽  
Fixed Times ◽  
Kinetics Of ◽  
Cirrhotic Group ◽  
Group 1

The kinetics of ammonia between blood and peritoneal fluid on 18 patiens was studied. Ten grams of ammonium citrate were given by mouth; the concentrations of ammonia in the blood and in the peritoneal fluid were comprared after determining the values at fixed times. The cases were divided in two groups: group 1, included eight patients with cirrhosis of the liver, group 2, included patients with ascites of other than liver cirrhosis aetiology, five of whom had carcinoma of the liver and'or of the peritoneal, two patients with lymphosarcoma, one with kidneysarcoma (Bour neville Syndrome) and two cases with congestive heart failure. The following conclusions have drawn : 1. The ammonia concentrations in the ascitic fluid of the cirrhotic group (group 1) before ammonium citrate loading was found to be higher than in the blood. 2. The highest concentration of the ammonia in the ascitic fluid was found two hours after loading and fell to the pre-loading level three hours later. 3. The curve formed by the ammonia values and ascitic fluid is similar to that of the blood. 4. The values of blood —and ascitic fluid—ammonia and the respective ourves in cases of cardiac failure resembled those found in cirrhotics. 5. In cases of neoplasms the fluctuations of ammonia concentrations in the blood and in the peritoneal fluid are minimal and the curves are flat. 6. In lymphosarcoma and kidneysarcoma the pre-loading values of blood ammonia are higher than in the peritoneal fluid.7. High concentration of blood and peritoneal fluid ammonia without appreciable fluctuations might suggest liver cancer on cirrhotic substrate.

Modelling of microbial processes that govern degradation of organic substrates in soil, with special reference to pesticides

1990 ◽  
Vol 329 (1255) ◽  
pp. 369-373 ◽  
Keyword(s):  
Microbial Population ◽  
Large Fraction ◽  
Organic Substrates ◽  
High Concentration ◽  
Deterministic Models ◽  
Soil Microbial ◽  
Low Concentrations ◽  
Biokinetic Parameters ◽  
Soil Microbial Population ◽  
Kinetics Of

We tried to develop deterministic models for kinetics of 2,4-D breakdown in the soil based on the following considerations: (i) at low concentrations degradation results from maintenance consumption by a large fraction of the soil microbial population; (ii) at high concentration in addition to the maintenance consumption there is a growth-associated carbon incorporation by a small specific microbial population. Values for the biokinetic parameters are consistent with those commonly found in the literature. Comparison between observed and simulated curves suggests that a non-negligible part of the pesticidal carbon exists as microbial by-products.

scholarly journals Leukocyte Antibodies in Human Sera and in Immune Rabbit Sera

Blood ◽  
1957 ◽  
Vol 12 (11) ◽  
pp. 953-971 ◽  
Author(s):  
ROY L. WALFORD ◽  
E. TAYLOR PETERSON ◽  
PATRICIA DOYLE
Keyword(s):  
Antibody Formation ◽  
Agar Plate ◽  
Human Leukocyte ◽  
Delayed Reaction ◽  
Human Leukocytes ◽  
Human Sera ◽  
Set Up ◽  
Antigen Antibody ◽  
Leukocyte Antibody ◽  
Immune Rabbit

Abstract A study of leukocyte antibodies is presented using (1) the sera of rabbits immunized with human leukocytes, and (2) the sera of three patients screened for the presence of such antibodies from among 36 patients with hematologic disease, 31 of whom (including the 3 studied in detail) had received multiple transfusions. The following technics are described and were employed: Leukoagglutination, leukoprecipitation including tube and agar-plate methods, agglutination of antigen-coated tanned and untanned sheep erythrocytes, the effect of antisera upon phagocytosis of heat-killed staphylococci by leukocytes, and upon ameboid motility of leukocytes. The leukoagglutinin test gives reliable clearcut results providing that appropriate controls are included and certain criteria adhered to, in order to facilitate the recognition of clumping due to other factors than true antigen-antibody union. No leukoprecipitins were detected in human sera with the technics used in this study. Immune rabbit sera, on the other hand, gave two reaction-lines in agar media, when set up against leukocyte extract. Immune rabbit sera reacted strongly with antigen-coated tanned sheep red blood cells. Human sera did not so react. One of the three selected human sera reacted with antigen-coated untanned erythrocytes, suggesting the presence of a polysaccharide antigen extractable from human leukocytes and capable of stimulating antibody formation in the human. Immune rabbit sera, and other human sera, did not react in this test. A suggestive but perhaps not a conclusive effect upon phagocytosis of bacteria by leukocytes exposed to human leukocyte antibody for 1 hour could be demonstrated. By means of ameboid motility studies, a cytotoxic effect of the human antisera upon human leukocytes could be demonstrated after 18 hours of incubation, but not after 3 hours. This was interpreted as evidence of a delayed reaction. Certain cardinal points from a clinical and theoretical standpoint with regard to the genesis of leukocyte antibodies in man are briefly reviewed. A possible analogy between leukocyte antibody formation and the homograft reaction is discussed. It is suggested that the rarity of leukocyte iso-antibody formation following transfusion is related to the fact that the intravenous pathway may be a poor route of immunization for these antigens.

Kinetics of enzymatic O-methylation: its value in assays for catecholamines in plasma.

1984 ◽  
Vol 30 (1) ◽  
pp. 24-27 ◽  
Author(s):  
L Mason ◽  
C Weinkove
Keyword(s):  
Mathematical Analysis ◽  
Plasma Catecholamines ◽  
High Concentration ◽  
Internal Standards ◽  
Linear Approximations ◽  
Endogenous Catecholamine ◽  
Radioenzymatic Assay ◽  
Exponential Equations ◽  
Kinetics Of ◽  
Catecholamine Concentration

Abstract The kinetics of enzymatic O-methylation of catecholamines were studied under conditions like those used in the radioenzymatic assay of plasma catecholamines. Inappropriate Michaelis-Menten kinetics and linear approximations of exponential equations were not used. Mathematical analysis indicated the importance of the ratio of methyl donor (S-adenosylmethionine) to substrate (catecholamine) concentration. If the reaction is incomplete, only a large ratio will allow linear approximations between product formed and initial catecholamine concentration. The use of high-concentration internal standards to correct for plasma interference may give erroneous results by reducing this ratio. Accuracy will be improved by ensuring (a) that S-adenosylmethionine is always greatly in excess of catecholamine, (b) that concentrations of added standards are of the same order as for endogenous catecholamine, and (c) that a high activity of enzyme is used, to allow the reaction to reach completion even in the presence of some inhibition.

scholarly journals PERIODATE OXIDATION OF PEG–600, AN ESSENTIAL PHARMACEUTICAL POLYMER

2019 ◽  
pp. 251-256
Author(s):  
K. V. S. KOTESWARA RAO ◽  
R. VENKATA NADH ◽  
K. VENKATA RATNAM
Keyword(s):  
Polyethylene Glycol ◽  
Oxygen Atom ◽  
Temperature Dependence ◽  
Reaction Rate ◽  
Periodate Oxidation ◽  
Alkali Concentration ◽  
Rate Of Reaction ◽  
Atom Loss ◽  
Kinetics Of ◽  
Peg 600

Objective: To study the kinetics of periodate oxidation of polyethylene glycol-600 (PEG-600), a familiar non-toxic polymer used in pharmaceutical and other fields of industry. Methods: Reactions were carried out in alkaline medium and measured the kinetics by iodometry. One oxygen atom loss or two electrons transfer was observed per each molecule of periodate i.e., the rate of reaction was measured periodate converts to iodate because the formed iodate species is unable to oxidize the substrate molecules. Results: Based on log (a-x) versus t plots, order w. r. t. oxidant (periodate) is unity. Reactions were found to be independent of substrate (PEG-600) concentration. A decrease in rate with an increase in alkali concentration [OH–] was found and order was inverse fractional. Temperature dependence of reaction rate was studied and then calculated the corresponding Arrhenius parameters. Conclusion: An appropriate rate law was proposed by considering the above experimental results.

scholarly journals THE PERIODATE-SCHIFF REACTION: SPECIFICITY, KINETICS, AND REACTION PRODUCTS WITH PURE SUBSTRATES

1965 ◽  
Vol 13 (6) ◽  
pp. 423-430 ◽  
Author(s):  
ARNE DAHLQVIST ◽  
INGE OLSSON ◽  
ÅKE NORDÉN
Keyword(s):  
Nucleic Acids ◽  
Simple Relation ◽  
Test Tube ◽  
Reaction Products ◽  
Chromatographic Mobility ◽  
Reaction Specificity ◽  
Rate Of Reaction ◽  
Pure Substances ◽  
Schiff Reaction ◽  
Aldehyde Groups

A quantitative test-tube method has been used to study the periodate-Schiff reaction of a number of pure substances. The rate of reaction, the amount of color produced, and in some cases the amount of periodate consumed, have been measured. The dye produced by different carbohydrates has been analyzed by spectrophotometry and paper chromatography. Glycogen, starch and dextran reacted slowly and produced much less color than the corresponding amount of free monosaccharides. Oligosaccharides and heteropolysaccharides were either periodate-Schiff-negative or very weakly positive. Proteins and nucleic acids were negative. There was no simple relation between the intensity of the periodate-Schiff reaction and the amount of periodate consumed or the amount of aldehyde groups formed on the oxidation by periodate. The dyes formed with different carbohydrates had essentially the same absorption curve, but differed in their chromatographic mobility.

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