bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis for Procainamide and N-Acetyl Procainamide in Plasma or Serum by High-Performance Liquid Chromatography
Authors: Rocco Richard M , Abbott Donald C , Giese Roger W , Karger Barry L 
Published: January 2020

Abstract
A high-performance liquid chromatographic method is presented for simultaneous analysis for procainamide and N-acetyl procainamide in plasma or serum. The procedure involves internal-standard addition, organic extraction, and separation on a reversed-phase column. The detection limit for procainamide is 0.1 mg/liter and the calibration plot is linear to at least 30 mg/liter. Comparison with a colorimetric assay for procainamide gave a correlation coefficient of 0.989. We checked for interference by a large series of appropriate drugs, and found none, nor did icteric or lipemic sera present problems
Spectrophotofluorometric Assay for Isoniazid and Acetyl Isoniazid in Plasma Adapted to Pediatric Studies
Authors: Olson William A , Dayton Peter G , Israili Zafar H , Pruitt Albert W 
Published: January 2020

Abstract
We modified the micro-scale spectrophotofluorometric method of Miceli et al. [Biochem. Med. 12, 348 (1975)] for the assay of "apparent" isoniazid (isoniazid plus acid-labile hydrazones) to improve its clinical application. We also adapted the method for determination of acetyl isoniazid. Data are presented showing how long plasma containing isoniazid may validly be stored. The applicability of the method was demonstrated in studies on children and small animals.
Use of Tetramethylbenzidine in Plasma Hemoglobin Assay
Authors: Standefer J C , Vanderjagt Dorothy 
Published: January 2020

Abstract
Plasma hemoglobin can be assayed by substituting 3,3',5,5'-tetramethylbenzidine for benzidine (a carcinogen) as the chromogenic reducing substance. Sensitivity, precision, and accuracy compare well with methods in which benzidine is used. Plasma inhibition can be ac¬commodated by preincubation with hydrogen peroxide.
Interference with the Enzymic Measurement of Cholesterol in Serum by Use of Five Reagent Kits
Authors: Pesce Michael A , Bodourian Selma H 
Published: January 2020

Abstract
We describe the effects of uric acid, hemolysis, drugs, ascorbic acid, lipemia, and bilirubin on the enzymic measurement of cholesterol in serum by use of reagent kits from Abbott, Beckman, Boehringer Mannheim, Cal¬biochem, and Worthington. In all of these, the chromogen formed from the reaction of hydrogen peroxide with phenol and 4-aminoantipyrene is measured. The absorbance was measured at 500 nm vs. a serum blank for each kit—except Abbott's, with which the recorded absorbances were the differences between readings at 500 and 600 nm. With all reagent kits, there was no interference from uric acid up to 200 mg/liter, hemoglobin up to 1.0 g/liter, or drugs (clofibrate, phenobarbital, Ketochol, Ovral-28), but negative interferences from ascorbic acid. Except for the Abbott kit, the cholesterol values obtained for lipemic samples were lower than found with the comparison method [Abell et al., Stand. Methods Clin. Chem. 2, 26 (1958)]. With Abbott's reagent, for most lipemic samples, the values were the same. Bilirubin at concentrations of 200 mg/liter significantly decreased the cholesterol values with Beckman, Calbiochem, and Worthington reagent kits. With Boehringer Mannheim reagent a small negative in¬terference was observed and with Abbott reagent a small positive interference was observed when the bilirubin concentrations were 200 mg/liter.
Solid-phase enzyme immunoassay for hepatitis B surface antigen.
Authors: Wei R , Knight G J , Zimmerman D H , Bond H E 
Published: January 2020

Abstract
A solid-phase enzyme immunoassay is described for measuring hepatitis B surface antigen in human serum or plasma. Immunologically purified antibody labeled with horseradish peroxidase was used as the indicator. In the assay system, antibody-coated controlled-pore glass is used as a solid support and there are three sequential incubations, totaling 2 h, at room temperature. Results for serially diluted positive and reference sera compare favorably to radioimmunoassay in sensitivity and specificity.
Amylase activity in serum and urine: comparison of results by the amyloclastic, dyed-starch, and nephelometric techniques.
Authors: Lehane D P , Wissert P J , Lum G , Levy A L 
Published: January 2020

Abstract
We assayed serum and urine specimens for amylase activity by the nephelometric (I),dyed-starch (Amylochrome) (II), and mayloclastic (III) techniques. For serum, the correlation coefficients of the regression lines were: I vs. II, 0.978 (n = 106); I vs. III, 0.736 (n = 110); and II vs. III, 0.739 (n = 108). For urine, they were I vs. II, 0.938 (n = 49); and I vs. III, 0.752 (n = 46). Because calculation of the Kolmogorov-Smirnov statistic showed the distributions to be nongaussian, Spearman rank correlation coefficients were determined and showed that I and II correlated well but neither method correlated with III. The clinical data show that I and II gave above-normal activities in every case of pancreatitis, but III gave normal values in two of eight cases. In all cases, I and II were more sensitive, giving higher amylase activities (as compared with the upper limit of normal) than did III. The nephelometric procedure is most suitable for routine and emergency testing; the dyed-starch assay is equally sensitive and reliable, but less convenient. The amyloclastic procedure appears to be less reliable.
Canaline carbamoyltransferase in human liver as part of a metabolic cycle in which guanidino compounds are formed.
Authors: Natelson S , Koller A , Tseng H Y , Dods R F 
Published: January 2020

Abstract
This and previous papers examine the reasons for the relationship between the concentrations of guanidino-succinate and guanidinoacetate in human urine. With the demonstration here that extracts of human liver-tissue can mediate ureidohomoserine formation from canaline [(2-amino-4-aminooxy)-butyric acid] and carbamoyl phosphate, all steps in a cycle proposed for the production of guanidinoacetate and guanidinosuccinate have been documented. This includes synthesis of canavaninosuccinate from aspartate and ureidohomoserine, reductive cleavage of canavaninosuccinate to form guanidinosuccinate and homoserine, or, alternatively, lytic action on canavaninosuccinate to form fumarate and canavanine, and transamidination to glycine to form guanidinoacetate, regenerating the canaline. We propose that canaline originates from aspartate, but the precise mechanism by which canaline is formed needs to be elucidated.
Immunochemical determination of human lysozyme by laser nephelometry.
Authors: Goudswaard J , Virella G 
Published: January 2020

Abstract
The methods currently available for quantitative determination of lysozyme are based on the capacity of the enzyme to lyse Micrococcus lysodeikticus. Previous attempts to develop immunochemical assays have been reported, but the sensitivity was inferior to that of the most widely used lysoplate method. We describe the development of a sensitive immunochemical method for lysozyme assay in which the recently developed laser nephelometer is used. The sensitivity so achieved is at least comparable to that of the lysoplate method, and in some circumstances better. Results obtained by the lysoplate assay and the nephelometric assay correlate well. Among the advantages of our method are easier handling of larger numbers of samples, quicker results, and the possibility of assaying enzymatically inactive forms of the enzyme.
Assessment of a method for measuring serum thyroxine by radioimmunoassay, with use of polyethylene glycol precipitation.
Authors: Farid N R , Kennedy C 
Published: January 2020

Abstract
We assessed the efficacy of a new thyroxine radioimmunoassay kit (Abott) in which polyethylene glycol is used to separate bound from free hormone. Mean serum thyroxine was 88 +/- 15 (+/-SD) microgram/liter for 96 normal persons. Results for hypothyroid and hyperthyroid persons were clearly separated from those for normal individuals. Women taking oral contraceptive preparations showed variable increases in their serum thyroxine values. The coefficient of variation ranged from 1 to 3% within assay and from 5.4 to 11% among different assays. Excellent parallelism was demonstrated between thyroxine values estimated by this method and those obtained either by competitive protein binding or by a separate radioimmunoassay for the hormone.
Separation of hydroxyproline-containing protein from C1q (a subcomponent of complement) in serum.
Authors: Rosano C L , Hurwitz C 
Published: January 2020

Abstract
Precipitation of the euglobulin fraction from serum separates C1q from another hydroxyproline-containing protein(s), which remains in the serum-minus-euglobulin fraction. The presence of C1q in the euglobulin fraction has been verified by radial immunodiffusion assay, by sensitivity to collagenase, by hydroxyproline content, and by electrofocusing. The presence of another hydroxyproline-containing protein(s) in the serum-minus-euglobulin fraction has been verified by the same criteria. The isoelectric pH range of C1q is 6.1-7.0; the isoelectric pH range of the other hydroxyproline-containing protein(s) is 4.2-5.5.
Impact of posture on the "reference range" for serum proteins and calcium.
Authors: Humphrey K R , Gruemer H D , Lott J A 
Published: January 2020

Abstract
The impact of water shifts due to changes in posture has been reinvestigated for serum protein and calcium concentrations in a young, healthy population. We found that generaly accepted normal ranges for total serum protein, and to a lesser degree for total serum calcium, are not acceptable as a reference range for a hospitalized population that is predominantly in a supine position. Our data indicate a smaller biological variability for total protein and calcium for a reference population in the recumbent posture as compared to the same population in the upright position.
Enzyme-coupled measurement of uric acid in serum with a centrifugal analyzer.
Authors: White R M , Cross R E , Savory J 
Published: January 2020

Abstract
An early-reading blank-corrected end-point determination of uric acid in serum has been developed for use with a centrifugal analyzer. The method is based on a modification of the uricase (urate:oxygen oxidoreductase, EC 1.7.3.3)/catalase (hydrogen peroxide:hydrogen peroxide oxidoreductase EC 1.11.1.6)/aldehyde dehydrogenase (aldehyde:NAD(P)+ oxidoreductase, EC 1.2.1.5)-coupled analytical scheme reported by Haeckel [Z. Klin. Chem. Klin. Biochem. 14, 101 (1976)]. Sensitivity and precision of the method are excellent, and results compare well with those obtained by the Kageyama procedure [Clin. Chim. Acta 31, 421 (1971)].
Phospholipid composition of blood plasma, erythrocytes, and "ghosts" in sickle cell disease.
Authors: Schwarz H P , Dahlke M B , Dreisbach L 
Published: January 2020

Abstract
We examined the phospholipid composition of the plasma, of whole erythrocytes, and of "ghosts" of the erythrocytes from healthy volunteers, patients with sickle cell disease without crisis, and such patients in crisis, and found that phosphatidylglycerol in the plasma and "ghosts" was very significantly increased in sickle cell crisis but not in the absence of crisis. The significance of these findings is discussed.
Lysozyme determined in serum or urine by a simple nephelometric method.
Authors: Borgen J , Romslo I 
Published: January 2020

Abstract
We describe a nephelometric procedure for determination of lysozyme. A quantitative result is obtained in 2 to 3 min with 50 microliter of serum or urine. At a lysozyme concentration of 12.0 mg/liter, between-day precision was 3.4% and the analytical recovery 96.5-105.5%. The values obtained were a linear function of enzyme concentration below 50 mg/liter, and they agreed with those obtained by absorptiometric determination of the decrease in turbidity of a suspension of Micrococcus lysodeikticus.
A fetal intestinal-type alkaline phosphatase in hepatocellular carcinoma tissue.
Authors: Higashino K , Otani R , Kudo S , Yamamura Y 
Published: January 2020

Abstract
We examined 19 hepatoma tissues for alkaline phosphatase isoenzyme and found that six have both the Kasahara isoenzyme and an alkaline phosphatase with a unique electrophoretic mobility, in addition to the liver-type enzyme. From two of six carcinoma tissues, the abnormal enzyme was partly purified and subjected to a detailed analysis, which clarified that the abnormal enzyme resembled a fetal intestinal alkaline phosphatase in most of its enzymic and immunologic properties and also in properties that reflect enzyme structure. This fetal intestinal-type alkaline phosphatase was not found in 24 specimens of normal liver from adults. The relevance of fetal intestinal-type alkaline phosphatase to Kasahara isoenzyme and adult intestinal alkaline phosphatase is discussed. The fetal and adult intestinal alkaline phosphatases differ in electrophoretic mobility, heat stability, and reactivity with concanavalin A. The adult-type enzyme has two components; only the electrophoretically slower, neuraminidase-resistant one is described here.
Double-antibody radioimmunoassay for factor VIII-related antigen.
Authors: Green D , Reynolds N 
Published: January 2020

Abstract
A plasma protein required for the support of ristocetin-induced platelet aggregation was isolated from antihemophilic factor concentrate and radiolabeled with 125I. A double-antibody radioimmunoassay was developed, with use of specific rabbit anti-VIII related antigen serum and goat anti-rabbit globulin. The assay is sensitive, reproducible, and technically simple to perform. Values obtained in normal subjects ranged from 0.65 to 1.53 units, similar to our normal range for VIII coagulant activity (0.67-1.43 units). However, normal or increased values of VIII-related antigen were observed in VIII coagulant-deficient hemophiliacs. Also, concentrations of VII-related antigen significantly exceeded coagulant concentrations in several patients with liver disease or disseminated intravascular coagulation, or both. Of a broad selection of congenital coagulation disorders examined, only patients with von Willebrand's disease had decreased VIII-related antigen concentrations, and these corresponded to the lowered concentration of ristocetin cofactor in the patients. In three transfused patients, VII-related antigen values correlated with the concentration of the cofactor. Our results suggest that the radioimmunoassay of VIII-related antigen is a simple and valuable adjunct in the study of patients with clotting abnormalities.
The sulfophosphovanillin reaction for serum lipids: a reappraisal.
Authors: Johnson K R , Ellis G , Toothill C 
Published: January 2020

Abstract
New evidence is presented for the mechanism of this reaction, which is used in estimating lipids. The reaction occurs in two stages: (a) Stage 1 evidently involves an oxidation step, forming a specific type of carbonium ion called an alkenyl cation of the general formula R--C+--C==C--R' (previous evidence had indicated that a carbonium ion of general formula R--C+--R' was formed by protonation only.) (b) Stage 2 of the reaction was examined by nuclear magnetic resonance studies and by partition experiments, which have indicated that a vanillin phosphate ester is not formed as previously suggested. Comparative data from other acid-aldehyde reactions indicate that in this reaction 1,1-di(4-hydroxy-3-methoxy phenyl)ethylene ion is formed, a product compatible with the formation of an alkenyl cation at stage 1.
Simultaneously obtained skin-puncture serum, skin-puncture plasma, and venous serum compared, and effects of warming the skin before puncture.
Authors: Blumenfeld T A , Hertelendy W G , Ford S H 
Published: January 2020

Abstract
Specimens of skin-puncture serum and plasma and venous serum were simultaneously obtained from healthy adults and in each specimen the concentrations of 12 chemical constituents were measured. No clinically important difference was found in the concentrations of the constituents measured in skin-puncture serum and plasma with or without warming the skin before puncture. When the concentration of each of the measured constituents was compared in skin-puncture specimens and venous serum there were important differences in the concentrations of glucose, potassium, total protein, and calcium. Except for glucose, the concentrations of these were higher in venous serum. The degree of hemolysis was the same in skin-puncture serum and plasma, but less in venous serum. The greater hemolysis in skin-puncture specimens was not reflected in a clinically important increase in the values of lactate dehydrogenase and potassium. We conclude that there is a difference in the concentration of some chemical constituents in skin-puncture specimens and venous serum and that these differences should be considered when results for these types of specimens are compared.
Analytical performance and comparability of the determination of cholesterol by 12 Lipid-Research Clinics.
Authors: Lippel K , Ahmed S , Albers J J , Bachorik P , Cooper G , Helms R , Williams J 
Published: January 2020

Abstract
Twelve Lipid-Research Clinic laboratories performed automated cholesterol analyses on four control-serum pools of known cholesterol concentration, using the Liebermann-Burchard reaction. The analyses were done during a two-year period, with the same standards, methodology, and quality-control procedures. Estimates of analytical bias, variability, and short- and long-term trends for each instrument and for the entire group of LRC instruments are presented. High accuracy, precision, and interlaboratory comparability were achieved through the rigorous standardization and control of the entire analytical procedure. The significance of these results for long-term collaborative studies is discussed. Individual laboratory biases averaged from 0.5 to 2.0% below Abell-Kendall reference values. Between-run variability was about equal to within-run variability and inter-laboratory variation was substantially less than intra-laboratory variation. The total standard deviation for all instruments was about 0.04 g/liter. Only 8-15% of this variation was due to differences between instruments. The between-instrument standard deviation ranged from 0.011 to 0.015 g/liter; the between-run, within-instrument standard deviation ranged from 0.023 to 0.030 g/liter; and within-run standard deviation ranged from 0.023 to 0.028 g/liter. The significance of the achieved results for long-term collaborative studies is discussed.
Faster radioimmunoassay of angiotensin I at 37 degrees C.
Authors: Fyhrquist F , Puutula L 
Published: January 2020

Abstract
We applied a 1-h radioimmunoassay incubation at 37 degrees C in determining generated angiotensin I in an assay for plasma renin activity. Under these nonequilibrium conditions, 26% of the 125I-labeled angiotensin I was bound at zero dose of unlabeled angiotensin, as compared to 57% at equilibrium after 18 h at 4 degrees C. Sensitivity and useful range for the standard curve remained unchanged. Blanks were not altered. There was a good (r = .971) correlation between renin values in 120 plasma samples from hypertensive patients as measured with both procedures. With isoelectric focusing, we detected no damage to the labeled angiotensin I during incubation for 1 h at 37 degrees C in the presence of diluted plasma, disodium ethylenediaminetetraacetate, hydroxyquinoline, and neomycin. Analytical recovery of unlabeled angiotensin I added to the assay mixture was 98 +/- 2.3% (mean +/- SD). We conclude that our incubation conditions allow rapid and accurate assay of plasma renin activity to be completed in one working day.
Buffer-exchange column for rapid separation of carcinoembryonic antigen from perchloric acid.
Authors: Haagensen D E , Easterday R L , Stolle C A , Wells S A 
Published: January 2020

Abstract
A Sephadex G-50 medium (Pharmacia) buffer-exchange column has been developed for rapidly changing the medium for carcinoembryonic antigen from perchloric acid to acetate buffer. Analytical recovery of the extracted antigen exceeded 95%. Plasma for analysis can be so prepared and samples ready for analysis within an hour. The technique also results in uniform assay volume, thus eliminating this variable from the assay.
Plasma glucose measurement with the Yellow Springs Glucose Analyzer.
Authors: Chua K S , Tan I K 
Published: January 2020

Abstract
The Yellow Springs Glucose Analyzer, a device for the quantitative measurement of glucose concentrations, involves the use of immobilized glucose oxidase, incorporated on a membrane covering a hydrogen peroxide sensor. Operation of the instrument is simple. After an initial calibration, 25 microliter of plasma is injected into a reaction chamber. At 45 s a digital result for glucose is displayed. The within-batch coefficient of variation for the method is 1.2% or less for glucose concentrations of 0.94 to 3.98 g/liter. The between-batch coefficient of variation is 5.8% or less for glucose concentrations of 0.29 to 2.91 g/liter. Concentration and readout are linearly related to at least 4.6 g/liter. Analytical recoveries ranged from 100 to 102%. Carry-over was negligible. Values for glucose concentration obtained with the instrument compared well (r = 0.997) with those obtained with the Beckman Glucose Analyzer.
Lipoprotein cholesterol in the serum of children, as determined independently by two different methods.
Authors: Srinivasan S R , Ellefson R D , Whitaker C F , Berenson G S 
Published: January 2020

Abstract
We separately evaluated split specimens of serum for lipoprotein cholesterol in 38 five- to 14-year-old children, by the heparin/Ca2+ precipitation method and the ultracentrifugation/dextran sulfate precipitation method. Statistical analysis of the results indicated an excellent agreement (especially in beta- and alpha-lipoprotein cholesterol values) between results by the two methods. The percentage of alpha-lipoprotein cholesterol (mean +/- SD: 38.6 +/- 5.0) in children further confirmed the earlier observations that cholesterol derived from alpha-lipoprotein in children constitutes a relatively greater part of the serum total cholesterol than is true of adults.
Use of the Du Pont aca to measure cholesterol in high-density lipoprotein fractions prepared by the heparin/Mn2+ precipitation method.
Authors: Liedtke R J , Busby B , Batjer J D 
Published: January 2020

Abstract
The enzymatic cholesterol method used with the Du Pont aca has been modified to provide a reliable measurement of high-density lipoprotein cholesterol in serum after heparin/Mn2+ precipitation of the low- and very-low-density lipoproteins. Interference by Mn2+, equivalent to about 90 mg of cholesterol per liter, is decreased to less than 40 mg of cholesterol per liter by the presence of ethylenediaminetetraacetate (8 mmol/liter) in the diluent; the residual effect of Mn2+ is compensated by calibrating the aca with standards containing Mn2+ and heparin. With an 80-microliter sample, the sensitivity is 236 muA/mg per liter and linearity ranges from 50 to 1500 mg/liter. Average analytical recovery of cholesterol added to the high-density lipoprotein fraction was 103%. Diluted fractions give the expected results. Between-run reproducibility (CV) is 1.3 and 1.6% at 463 and 554 mg/liter. Correlation with the Lipid Research Clinics' procedure (25 samples) gave a regression line of y(aca) = 1.039x- 15, and a correlation coefficient of 0.997.
Evaluation of homogeneous enzyme immunoassay of serum thyroxine with use of bichromatic analysis.
Authors: Finley P R , Williams R J 
Published: January 2020

Abstract
We evaluated the homogeneous enzyme immunoassay ("EMIT") of serum thyroxine with use of an ABA- 100 Bichromatic Analyzer, modified with an auxiliary dispenser syringe and a dual probe assembly. The modification allows two reagents to be dispensed at one time. The sera must be pre-treated with 0.1 mol/liter NaOH. The procedure thereafter is entirely automated. Twenty-four patients' samples may be analyzed in 15 min of instrument time. Precision and accuracy are excellent, and results correlate well with those by radioimmunoassay.