Enzymic measurement of cholesterol in serum with the CentrifiChem centrifugal analyzer.

1977 ◽  
Vol 23 (2) ◽  
pp. 280-282 ◽  
Author(s):  
M A Pesce ◽  
S H Bodourian
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Nicotinic Acid ◽  
Cholesterol Oxidase ◽  
Correlation Coefficients ◽  
Cholesterol Esterase ◽  
Hantzsch Reaction ◽  
Rate Method ◽  
High Concentrations ◽  
Enzymic Assay

Abstract Cholesterol is measured by mixing 5 mul of sample with 350 mul of a reagent consisting of phenol, 4-aminoantipyrine, and the enzymes cholesterol oxidase, cholesterol esterase, and peroxidase. After 12 min, the resulting quinoneimine is measured at 520 nm. Readings and cholesterol concentrations are linearly related up to 4.0 g/liter. Lipemic sera and samples containing uric acid (up to 200 mg/liter), hemoglobin (up to 1 g/liter), and certain drugs (clofibrate, phenobarbital, nicotinic acid, Ketochol, Ovral-28), gave no interference. Abnormally high concentrations of bilirubin and ascorbic acid in serum lowered the cholesterol values. This enzymic assay, compared with the method of Abell and with a rate method that uses the Hantzsch reaction, gave correlation coefficients of 0.987 and 989, respectively.

Enzymatic Rate Method for Measuring Cholesterol in Serum

1976 ◽  
Vol 22 (12) ◽  
pp. 2042-2045
Author(s):  
Michael A Pesce ◽  
Selma H Bodourian
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Free Cholesterol ◽  
Cholesterol Oxidase ◽  
Ammonium Phosphate ◽  
Cholesterol Concentration ◽  
Kinetic Assay ◽  
Rate Method ◽  
Enzymatic Procedure ◽  
Positive Interference

Abstract An enzymatic rate assay is described for measuring cholesterol in serum. Cholesterol is anzymed by mixing 5 µl of sample with a reagent consistaing of cholesterol esterase, cholesterol oxidase, catalase, acetylacetone, methanol. and hydroxypolyethoxydodecane in a ammonium phosphate of the dihydrolutidine product is measured at 37 °C and 405nm. The change in absorbance between 4 and 10 min is used to calculated the cholesterol concentrations by using simultaneously determined free cholesterol standards. The change is linearly ralated to cholesterol concentration up to 4 g/liter. Samples containing bilirubin up to 200 mg/liter, uric acid up to 200 mg/liter, and hemoglobin up to 1 g/liter, or certain drugs (clofibrate, phenobarbital, nicotinic acid, salicylate, Ketochol, and Ovral) gave no interference. Ascorbic acid added to serum caused a positive interference. Lipemic samples gave values that were slightly lower than did the method of Abell et al., used for comparison. Our kinetic assay, compared with the method of Abell et al., the enzymatic assay used with Abbott's Bichromatic Analyzer, and the Technicon SMA 12/60 enzymatic procedure gave correlation coefficient of 0.992, 0.985, and 0.986, respectively.

Enzymatic rate method for measuring cholesterol in serum.

1976 ◽  
Vol 22 (12) ◽  
pp. 2042-2045
Author(s):  
M A Pesce ◽  
S H Bodourian
Keyword(s):  
Free Cholesterol ◽  
Cholesterol Oxidase ◽  
Ammonium Phosphate ◽  
Correlation Coefficients ◽  
Cholesterol Concentration ◽  
Kinetic Assay ◽  
Rate Of Increase ◽  
Rate Method ◽  
Enzymatic Procedure ◽  
Positive Interference

Abstract An enzymatic rate assay is described for measuring cholesterol in serum. Cholesterol is analyzed by mixing 5 mul of sample with a reagent consisting of cholesterol esterase, cholesterol oxidase, catalase, acetylacetone, methanol, and hydroxypolyethoxydodecane in a ammonium phosphate buffer at pH 7.0. The rate of increase in absorbance of the dihydrolutidine product is measured at 37 degrees C and 405 nm. The change in absorbance between 4 and 10 min is used to calculate the cholesterol concentrations by using simultaneously determined free cholesterol standards. The change is linearly related to cholesterol concentration up to 4 g/liter. Samples containing bilirubin up to 200 mg/liter, uric acid up to 200 mg/liter, and hemoglobin up to 1 g/liter, or certain drugs (clofibrate, phenobarbital, nicotinic acid, salicylate, Ketochol, and Ovral) gave no interference. Ascorbic acid added to serum caused a positive interference. Lipemic samples gave values that were slightly lower than did the method of Abell et al., used for comparison. Our kinetic assay, compared with the method of Abell et al., the enzymatic assay used with Abbott's Bichromatic Analyzer, and the Technicon SMA 12/60 enzymatic procedure gave correlation coefficients of 0.992, 0.985, and 0.986, respectively.

Evaluation of the co-immobilized hexokinase/glucose-6-phosphate dehydrogenase method for glucose, as adapted to the Technicon SMAC.

1978 ◽  
Vol 24 (7) ◽  
pp. 1186-1190 ◽  
Author(s):  
C C Garber ◽  
D Feldbruegge ◽  
R C Miller ◽  
R N Carey
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Glucose Oxidase ◽  
Total Error ◽  
Reference Method ◽  
Systematic Errors ◽  
Upper Limits ◽  
Rate Method ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Glucose Analysis

Abstract We assessed the analytical performance of the co-immobilized hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) method for D-glucose analysis on the Technicon SMAC. The enzyme-containing coils were usable for one month, or 12 000 tests. Bilirubin, hemoglobin, lipemia, creatinine, uric acid, citric acid, and ascorbic acid did not interfere. Results with this method were compared to those by the National Glucose Reference Method. The upper limits of the total error estimate (a combination of random and systematic errors) were 76, 74, and 125 mg/liter at concentrations of 500, 1200, and 3000 mg/liter, respectively. The error estimates were less than allowable errors based on medical usefulness; thus the method was judged to perform acceptably with respect to the Reference Method. We also present performance data for the routine SMAC glucose oxidase (EC 1.1.3.4)/Peroxidase (EC 1.11.1.7) 3-methyl-2-benzothianolinone hydrazone-N,N-dimethylaniline method, the direct hexokinase method with the Du Pont aca, and the glucose oxidase oxygen-rate method with the Beckman Glucose Analyzer.

Evaluation of the BMC glucose oxidase/peroxidase-4-aminophenazone-phenol procedure for glucose as adapted to the Technicon SMAC.

1979 ◽  
Vol 25 (10) ◽  
pp. 1844-1846 ◽  
Author(s):  
G V Purcell ◽  
D B Behenna ◽  
P R Walsh
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Glucose Oxidase ◽  
Serum Glucose ◽  
Analytical Performance ◽  
Upper Limit ◽  
Rate Method ◽  
Economical Alternative

Abstract We evaluated the analytical performance of Trinder's glucose oxidase (EC 1.1.3.4)/peroxidase (EC 1.11.1.7) 4-aminophenazone-phenol method for the quantification of serum glucose as adapted to the Technicon SMAC. Our results correlated well with those by the routine SMAC glucose oxidase/peroxidase 3-methyl-2-benzothiazolinone hydrazone-N,N-dimethylaniline method (y = 1.02x - 49.4; r = 0.99) and the glucose oxidase oxygen-rate method (y = 0.99x + 14; r = 0.99) with the Beckman Glucose Analyzer. Sample-to-sample interaction was less than 1%. Ascorbic acid or uric acid in concentrations as high as 200 mg/L were without demonstrable effect on results for glucose. Intra- and inter-assay precisions (CV) were 1.6 and 2.3%, respectively. The upper limit of linearity was about 5 g/L. Adaptation of the Trinder method for glucose to the SMAC is simple and provides an analytically acceptable and economical alternative to the methods ordinarily used with the SMAC.

Glucose Assay Systems: Evaluation of a Colorimetric Hexokinase Procedure

1971 ◽  
Vol 17 (10) ◽  
pp. 1010-1015 ◽  
Author(s):  
Walter R Wright ◽  
John C Rainwater ◽  
Lawrence D Tolle
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Reduced Glutathione ◽  
The Other ◽  
Phenazine Methosulfate ◽  
Tetrazolium Chloride ◽  
Glucose Assay ◽  
Standard Curve ◽  
High Concentrations ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract A colorimetric enzymatic assay system for glucose was evaluated. The system uses hexokinase (ATP:D-hexose 6-phospho-transferase; EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADP oxidoreductase; EC 1.1.1.49) coupled with a PMS-INT reaction (phenazine methosulfate; 2-p-iodophenyl-3-p-nitrophenyl-5-phenyl tetrazolium chloride). The precision, range of linearity, reproducibility of standard curve, and stability of reagents after reconstitution are excellent. The method is specific for glucose in the presence of mannose, fructose, galactose, xylose, and ribose. Uric acid, urea, ascorbic acid, reduced glutathione, or creatinine at abnormally high concentrations do not interfere. Good correlations (with unselected hospital sera) were obtained in parallel assays by ferricyanide (AutoAnalyzer), o-toluidine (manual), and hexokinase (manual) procedures. Results obtained by the neocuproine (SMA-12/30) method in the parallel assays were significantly different from results obtained by the other three procedures.

The 4-hydroxybenzoate/4-aminophenazone chromogenic system used in the enzymic determination of serum cholesterol.

1978 ◽  
Vol 24 (12) ◽  
pp. 2161-2165 ◽  
Author(s):  
F Meiattini ◽  
L Prencipe ◽  
F Bardelli ◽  
G Giannini ◽  
P Tarli
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Linear Regression ◽  
Serum Cholesterol ◽  
Reduced Glutathione ◽  
Cholesterol Oxidase ◽  
Dihydroxybenzoic Acid ◽  
Standard Curve ◽  
Analytical Recovery

Abstract A single reagent, containing cholesterol oxidase, cholesterol esterase, peroxidase, 4-hydroxybenzoate, and 4-aminophenazone, is used in determining serum cholesterol. Analysis time is 15 min, and the standard curve is linear to 6.0 g/liter. Analytical recovery of cholesterol was 100.1 +/- 0.4%. Within-run precision (CV) was less than or equal to 1.4 1.4%, between-run less than or equal to 4.8%. Comparison with results by a Liebermann Burchard method [Clin. Chim. Acta 5, 637 (1960)] gave a linear regression of y = 1.08x--0.05, with a correlation coefficient (r) of 0.985. Comparison with the Roeschlau enzymic method [J. Clin. Chem. Clin. Biochem, 12, 226 (1974)] gave y = 1.02x + 0.01 (r = 0.958). Comparison with the enzymic method of Allain et al. [Clin. Chem. 20, 470 (1974)] gave y = 1.01x--0.00 (r = 0.995). The following substances do not interfere up to the indicated concentrations (mg/liter): hemoglobin (5000), bilirubin (100), reduced glutathione (150), l-cysteine (400), urea (3000), creatinine (200), uric acid (200), d-glucose (10000), L-ascorbic acid (50), acetylsalicylic acid (500), L-DOPA (10), ergothioneine (1000), 2,5-dihydroxybenzoic acid (20), and 3,4-dihydroxybenzoic acid (10). Stored in an amber-colored bottle, the working reagent is stable for three months at 2--8 degrees C and for three weeks at 25 degrees C.

Natural Products and Extracts as Xantine Oxidase Inhibitors – A Hope for Gout Disease?

2020 ◽  
Vol 26 ◽  
Author(s):  
Ilkay Erdogan Orhan ◽  
Fatma Sezer Senol Deniz
Keyword(s):  
Natural Products ◽  
Uric Acid ◽  
Waste Product ◽  
Acid Synthesis ◽  
Intermediate Compound ◽  
Living System ◽  
Ginsenoside Rd ◽  
Drug Classes ◽  
Urate Crystal ◽  
High Concentrations

: Xanthine oxidase (EC 1.17.3.2) (XO) is one of the main enzymatic sources that create reactive oxygen species (ROS) in the living system. It is a dehydrogenase enzyme that performs electron transfer to nicotinamide adenine dinucleotide (NAD+ ), while oxidizing hypoxanthin, which is an intermediate compound in purine catabolism, first to xanthine and then to uric acid. XO turns into an oxidant enzyme that oxidizes thiol groups under certain stress conditions in the tissue. The last metabolic step, in which hypoxanthin turns into uric acid, is catalyzed by XO. Uric acid, considered a waste product, can cause kidney stones and gouty-type arthritis as it is crystallized, when present in high concentrations. Thus, XO inhibitors are one of the drug classes used against gout, a purine metabolism disease that causes urate crystal storage in the joint and its surroundings caused by hyperuricemia. Urate-lowering therapy include XO inhibitors that reduce uric acid production as well as uricosuric drugs that increase urea excretion. Current drugs that obstruct uric acid synthesis through XO inhibition are allopurinol, febuxostat, and uricase. However, since the side effects, safety and tolerability problems of some current gout medications still exist; intensive research is ongoing to look for new, effective, and safer XO inhibitors of natural or synthetic origins for the treatment of the disease. In the present review, we aimed to assess in detail XO inhibitory capacities of pure natural compounds along with the extracts from plants and other natural sources via screening Pubmed, Web of Science (WoS), Scopus, and Google Academic. The data pointed out to the fact that natural products, particularly phenolics such as flavonoids (quercetin, apigenin, and scutellarein), tannins (agrimoniin and ellagitannin), chalcones (melanoxethin), triterpenes (ginsenoside Rd and ursolic acid), stilbenes (resveratrol and piceatannol), alkaloids (berberin and palmatin) have a great potential for new XO inhibitors capable of use against gout disease. In addition, not only plants but other biological sources such as microfungi, macrofungi, lichens, insects (silk worms, ants, etc) seem to be the promising sources of novel XO inhibitors.

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