bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological and Analytic Components of Variation in Long-Term Studies of Serum Constituents in Normal Subjects
Authors: Cotlove Ernest , Harris Eugene K , Williams George Z 
Published: January 2020

Abstract
Biological components of variation for each of 15 serum constituents have been estimated in 68 normal subjects by weekly measurements over several months, and concurrent measurements on invariant human serum pools. Intra-individual coefficient of variation was smallest, less than 2%, for Na, Cl, Ca, Mg; 3 to 4% for CO2, albumin, and total protein; 5 to 7% for K, glucose, cholesterol, and phosphate; and largest, 9 to 12%, for uric acid, urea nitrogen, SGOT, and LDH. Inter-individual variation was larger than intra-individual variation for all 15 tests except Cl, CO2, and K. Analytic deviation was as large as or larger than biological (intra- or inter-individual) variability for constituents, such as calcium, which are under precise homeostatic control, thus producing artifactual widening in the observed normal range and obscuring the borderline between normal and abnormal results. Limits of tolerable variability in laboratory procedures are proposed, based on composite intra- and inter-individual variation, that would permit medically significant deviations in results to be detected. Such limits were exceeded by current methodology in at least half the 15 tests.
Measurement of Total Calcium in Serum by Atomic Absorption Spectrophotometry, with Use of a Strontium Internal Reference
Authors: Pybus John , Feldman Fredric J , Bowers George N 
Published: January 2020

Abstract
A method for total calcium in serum was optimized, a dual double-beam atomic absorption spectrophotometer being used, with strontium as an internal reference. The effect of HCl and lanthanum concentrations on the signals of both calcium and strontium was determined. The final analysis was unaffected by known sources of interference in serum at a 50-fold dilution of serum in 50 mmolar HCl containing 10 mmol LaCl3 and 0.12 mmol of SrCl2 per liter. Within-run precision for 30 replicate analyses performed during 30 min gave a relative standard deviation (RSD) of 0.36% for the internal strontium reference mode vs. 0.72% RSD for the single-channel mode. Nine consecutive multiconcentration control pools were measured repeatedly for two years; the median RSD was 2.3%. With meticulous technique, long-term variability for total calcium in serum approached 1%. Accuracy is believed to be limited only by the precision, since systematic bias was not detected from recovery studies and comparisons with results of ashing procedures or oxalate precipitation techniques.
Direct Potentiometric Measurement of Potassium in Blood Serum with Liquid Ion-Exchange Electrode
Authors: Wise W M , Kurey M J , Baum G 
Published: January 2020

Abstract
A new liquid ion-exchange electrode is described which has a selectivity for K+ over Na+ of 93:1 in 0.1 mol/kg solutions. Its response is Nernstian in the range 5 x 10-4 to 5 x 10-1 mol KCl per kg. The dip-type electrode responds to small changes in K+ in mixed salt solutions containing the same quantities of KCl and NaCl as human blood serum. A miniaturized form of the electrode was adapted to a capillary flow-through system for blood sera. It gives results for K+ in the normal range that agree with flame photometric values without correction for Na+ in the concentrations normally present. The effect of pH on the K+ response and the response of the electrode to Mg++, Ca++, NH4+, Rb+, and Cs+ are also illustrated.
Quantitation of Plasma Testosterone by Improved Competitive Protein-Binding Technique
Authors: Demetriou J A , Austin F G 
Published: January 2020

Abstract
A method is described for quantitation of testosterone in plasma from females and males. The principal operations of extraction, chromatographic fractionation, and competitive protein-binding assay can be completed for eight duplicate samples in a single day. Experimental data used in the development of the test and the rationale for the specific operations and conditions are presented. The specificity of the method was established by comparing plasma testosterone concentrations determined by the double isotope derivative technique. Concentrations are reported for normal female and male subjects, and for patients with hirsutism, adrenal hyperplasia, Klinefelter’s syndrome, and other endocrine conditions.
Determination of Free Thyroxine in Serum by Low-Temperature Equilibrium Dialysis
Authors: Fang Victor S , Selenkow Herbert A 
Published: January 2020

Abstract
Equilibrium dialysis of thyroxine (T4) in diluted serum at low temperature gives consistent and reproducible values for the dialyzable fraction (DF) of this hormone. The quantity of serum required for the determination is minimized by dilution, which is technically advantageous. Variations caused by temperature, dialysis time, dilution of serum, buffer system, and stability of 125I-T4 could be controlled by parallel use of a normal reference serum in each experiment. The reference serum was assigned a DF value of 0.04%, which was corrected by a factor derived from the ratio of assigned DF to the observed DF calculated from the experimental data for this reference serum. This correction factor permits the observed DF results for concurrent unknown samples to be related to the values for the DF of the normal reference serum. The free thyroxine concentration is calculated from the product of the DF and the total serum thyroxine concentration as determined by competitive binding analysis. The method is convenient for use in clinical laboratories, and data for free thyroxine obtained from patients with metabolic thyroid disorders are diagnostically discriminatory.
Semiautomated Method for Serum Pepsinogen Determination
Authors: Wenger Julius , Munro Miranda 
Published: January 2020

Abstract
An automated fluorometric determination of tyrosine has been adapted to the measurement of pepsinogen in body fluids. Preparation of the hemoglobin substrate and methods of incubation are similar to those previously described. The major technical improvement is the elimination of precipitation and filtration; instead, dialysis has been incorporated into the automated procedure for determination of tyrosine and tyrosine-containing peptides. This method provides a reliable, simple technique for use with large numbers of serum specimens.
Contribution of Estriol to Total Urinary Estrogens during Pregnancy
Authors: Hobkirk R , Anuman-Rajadhon Y , Nilsen M , Blahey P R 
Published: January 2020

Abstract
Estriol accounts for an average of 74% of the principal Kober-positive steroids in the urine of 13 women during uncomplicated pregnancies. This proportion is independent of the stage of pregnancy, from 20 weeks until term. The average ratio of estriol to ring-D α-ketols (mainly 16α-hydroxyestrone and 16-ketoestradiol-17β) is about 5:1 over the same period. In 17 pregnant women with diabetes, urinary estriol averaged 63% of the "total steroids" during a similar period, and the average ratio of estriol to ring-D α-ketols was 3:1. The quantitative importance of these ketolic steroids may introduce a problem in deciding whether to measure estriol or "total estrogens" when evaluating fetal viability in complicated pregnancies.
Usefulness of Serum Lipase, Esterase, and Amylase Estimation in the Diagnosis of Pancreatitis—a Comparison
Authors: Song Harriet , Tietz Norbert W , Tan C 
Published: January 2020

Abstract
Sera of 19 individuals with clinically established pancreatitis were analyzed for lipase activity on emulsion-type and aqueous substrates. Serum amylase concentrations were compared. Results obtained on the first and subsequent days of hospitalization clearly indicated that methods for lipase determination in which an emulsion-type substrate is used are of the greatest aid in diagnosing pancreatitis (90 to 92% of patients with pancreatitis had supranormal results). Amylase determinations were nearly as useful as an index (78% correlation), but "lipase" values obtained with methods in which aqueous substrates are used had limited clinical usefulness (29 and 32% correlation). Serum lipase elevations in cases of pancreatitis were generally greater than amylase elevations, with some exceptions. Serum lipase should be determined with a method in which emulsion-type substrates are used. Lipase and amylase values supplement one another.
In Vitro Formation of Ammonia in Blood of Dog and Man
Authors: Prytz Bo , Grossi Carlo E , Rousselot Louis M 
Published: January 2020

Abstract
A significant (p &lt;0.001) difference was found in the rate of ammonia formation and the amount formed in heparinized dog and human blood at 4°C. The initial ammonia concentration and the increase in ammonia formation with time were correlated for human blood. This in vitro ammonia formation was not prevented by certain enzyme inhibitors, but it continued after cells and plasma were exhaustively dialyzed against water or saline, suggesting that it originates from enzyme action.
Free-Electrophoretic Behavior of Urea-Insulin Reaction Products
Authors: Bischoff Fritz , Bakhtiar Abolfath Khan 
Published: January 2020

Abstract
Five reaction products, previously isolated from an aqueous mixture of insulin and concentrated urea that had been subjected to various conditions of time and temperature, were examined by moving-boundary electrophoresis. Insulin OU and insulin IU separated into major and minor peaks with mobilities identical to those observed by Timasheff et al. (and confirmed by us) for intact crystalline insulin. Insulin IIU showed a major peak (80%) with a mobility of -7.6 x 10-5 cm/s/V/cm. Insulin IIIU showed a major peak with a mobility of -9.2 x 10-5 cm/s/V/cm. On the basis of change in electron charge and the fact that guanidine does not produce the effects of urea, it is postulated that the delayed-acting urea insulin (IIU) is formed by native insulin reacting with the isocyanate ion in urea solution.
A Method for Determination of Cystine in Urine
Authors: Haux Peter , Natelson Samuel 
Published: January 2020

Abstract
A procedure is described for the assay of cystine in urine. Cystine is ad-sorbed on a column of Dowex-50 resin at pH 2, which is then washed with water and eluted with sodium acetate solution. Color is developed with 1,2-naphthoquinone-4-sulfonate. Homocystine does not interfere in the reaction. Routine reproducibility in the laboratory was ±10.3% (2 SD) for 24 normal urines, which contained 8 to 86 mg cystine per 24 h (those values falling within 2 SD). Mean recovery was 94.5%. In two cases in which the results were compared with those obtained with the amino acid analyzer, the method was indicated to be valid for screening urine to detect cystinuria
A Semiautomated Nonincineration Technique for Determining Serum Thyroxine
Authors: Kessler Gerald , Pileggi Vincent J 
Published: January 2020

Abstract
Thyroxine and triiodothyronine are separated from other serum iodine-con-taining constituents by column chromatography. The iodine compounds of a serum sample adjusted from pH 10 to 11 are absorbed on an anion-ex-change resin, which is washed to remove serum proteins, mono- and diio-dotyrosines, and some organic iodine compounds of exogenous origin. Thyroxine and triiodothyronine are quantitatively eluted with 50% acetic acid and then measured by the Ce+4-arsenite reaction by use of the Auto-Analyzer. The eluates are automatically added to a reaction mixture contain-ing sulfuric acid and bromate-bromide reagent. The resulting bromine inac-tivates unidentified inhibitors and enhances the catalytic activity of thyrox-ine, thus eliminating the necessity for incineration or wet-digestion. Arsen-ous acid and Ce+4 reagents are then added to initiate the iodide-catalyzed Ce+4 arsenite reaction. On passing through two 13-m glass coils at 60°C, Ce+4 in the reaction mixture is reduced to colorless Ce+3 by iodine released from the thyroxine molecule, and measured colorimetrically at 400 nm. The analytical rate is 50 specimens per hour. Recovery data utilizing is pre-sented for the chromatography steps. The total system recovery for T4 averaged 98% (range, 85 to 112%) with a precision of ±8.5%(±2 CV). Interfer-ence by 19 organic contrast media was evaluated
Nomogram for Calculation of Creatinine Clearance
Authors: Gindler E Melvin 
Published: January 2020

Abstract
An alignment chart nomogram, actually a combination of three nomograms, is presented for use in the calculation of creatinine clearance over a broad range of serum and urine concentrations. Urine collection times may range from 1.5 to 30 h. Examples are given of the use of the nomogram. The significance of the creatinine clearance equation is briefly discussed.
Reaction of Sodium Aminohippurate with Folin’s Reagent
Authors: Rahill W J , Wilson A C , Stubbins M 
Published: January 2020

Abstract
In the Lowry method for protein, 1 mg of p-aminohippurate gives a color equivalent to 0.6 mg of protein. This method should not be used on fluids from patients receiving p-aminohippurate.
Emergency Gas—Liquid Chromatographic Determination of Barbiturates and Glutethimide in Serum
Authors: Sine H E , McKenna M J , Rejent T A , Murray M H 
Published: January 2020

Abstract
A method is presented for the rapid gas chromatographic determination of barbiturates and glutethimide in serum, suitable for use in clinical emergencies. The sample is prepared for gas chromatography by acidification and a single extraction with chloroform. From 70 to 100% of the various barbiturates and glutethimide are analytically recovered, with a coefficient of variation of 8 to 10% for the method. During a 10-month clinical evaluation (87 requested determinations), 34 analyses (39% of the samples submitted) were positive for barbiturates, glutethimide, or both.
Atomic Absorption Spectrophotometry of Rubidium in Biological Fluids
Authors: Sutter E , Platman S R , Fieve R R 
Published: January 2020

Abstract
The atomic absorption spectrophotometric method for measurement of rubidium in serum, plasma, whole blood, and urine was evaluated, and the effects of interfering ions were studied. Absorbance was most enhanced by potassium and sodium; calcium, bicarbonate, and chloride at the concentrations found in serum did not affect rubidium absorption. Naturally occurring rubidium concentrations in serum, plasma, whole blood, and urine are 3, 4, 70, and 18 µEq/liter, respectively, much lower than expected therapeutic concentrations. Methods for preparing standards, optimum instrument settings, and special treatment of samples were established with specimens from monkeys treated with rubidium. These procedures are applicable to human bloods from patients receiving rubidium therapy when such therapy is begun for treatment of affective disorders.
The Microscope, Spectra, and Automated Analysis
Authors: West Seymour S 
Published: January 2020

Abstract
Fluorescence spectroscopy (FS) and optical rotatory dispersion (ORD) have been added to the capabilities of the microscope. With them, as with conventional spectroscopy, a single component can be detected, even when in a mixture. This ability is enhanced by use of certain fluorescent dyes or "molecular probes" such as acridine orange (AO). Molecular complexes between dye and substrate may have characteristic physical-optical and physical-chemical properties. The microscope used for FS and ORD studies can produce fluorescence- and ORD-spectra from selected portions of unfixed cells and tissues and from extremely small amorphous samples. Characteristic spectra can be obtained from as little as 10-17 moles of sample. It is possible to obtain cytochemical data that closely resembles, both spectroscopically and numerically, data obtained from solution studies on in vitro model systems, and consequently it is possible to predict quantitatively the results of interaction of cells with dye. Previous work in cytochemistry cannot produce such correlations, nor is it useful for quantitative prediction. Data so obtained with the microscope and corrected for instrumental parameters, can be used in design of automated analytical systems capable of detecting and quantitating particular biopolymers even in an intact unfixed cell. When a particular biopolymer can serve (qualitatively or quantitatively) to characterize a cell type, automated identification, counting, and separation can readily be devised from predetermined optical properties. The fluorescence and ORD spectra of the microscopic samples determine the complexity of the automated systems. Not only can relatively simple instruments sometimes serve, but automation of an analysis that cannot be definitive can be avoided.
Preliminary Results from High-Resolution Analyses of Ultraviolet-Absorbing and Carbohydrate Constituents in Several Pathologic Body Fluids
Authors: Jolley Robert L , Scott Charles D 
Published: January 2020

Abstract
Human urine, blood serum, cerebrospinal fluid, and amniotic fluid have been analyzed by high-resolution chromatographic systems under development at the Oak Ridge National Laboratory. These systems, or analyzers, consist of heated, high-pressure anion-exchange columns for chromatographic separation of the constituents and continuous-flow ultraviolet spectrophotometry or phenol-sulfuric acid colorimetry for detection of the separated ultraviolet-absorbing or carbohydrate components. Quantification of the resulting chromatograms has revealed significant differences in the concentrations of body-fluid constituents for the normal state and for various pathologic states such as hereditary nephritis, Lesch-Nyhan syndrome, gout, alkaptonuria, and maple syrup urine disease. Some changes in urinary chromatographic patterns resulting from nicotinic acid and allopurinol therapies have also been detected.
Serum Organic Acids in Sheep Exposed to Neutron—Gamma Irradiation, Air Blast, or Both
Authors: Henderson Thomas R , Jones Robert K 
Published: January 2020

Abstract
Organic acids were measured in serum from sheep that had been exposed to neutron—gamma irradiation, air blast, or both to determine which concentrations change after experimental injury. Samples were directly analyzed by partition chromatography and indicator titration. The semiautomated instrument efficiently separates mixtures of monocarboxylic acids. Monocarboxylic acids in serum seem to be sensitive indicators of biological injury. Survey experiments showed that lactate and propionate accumulate in sheep serum after severe air-blast injury, but only propionate after irradiation. Propionate-loading studies suggested that the utilization of injected propionate is impaired, to various degrees, in fasting, irradiation, and air blast. However, presumptive impairment of propionate utilization occurred earlier in sheep exposed to irradiation and blast than in only irradiated animals, and earlier in irradiated animals than in fasting controls. Air blast exposure resulted in effects of only borderline significance.
Effect of Dietary Purine Restriction, Allupurinol, and Oxipurinol on Urinary Excretion of Ultraviolet-Absorbing Compounds
Authors: Kelley William N , Wyngaarden James B 
Published: January 2020

Abstract
We demonstrate that purine restriction is associated with a decreased excretion of a number of uv-absorbing compounds—including uric acid, hypoxanthine, xanthine, adenine, pseudouridine, and 5-acetylamino-6-amino-3-methyluracil—indicating that these compounds originate, at least partly, exogenously. Administration of allopurinol and oxipurinol is associated with a decreased excretion of uric acid and an increased excretion of hypoxanthine and xanthine, as well as the excretion of the previously identified products of allopurinol and oxipurinol metabolism. Moreover, these drugs further decrease excretion of 5-acetylamino-6-amino-3-methyluracil, increase uracil excretion slightly, and strikingly increase orotic acid and orotidine excretion. No change in pseudouridine excretion was observed. The ultraviolet-analyzer is a valuable tool for detecting qualitative changes in the excretion of ultraviolet-absorbing compounds in the urine; with it, identified peaks can be semiquantitated.
Serum Content of Macroglobulins (19S Fraction) and Its Variation with Age when Determined by Thin-Layer Gel-Filtration
Authors: de Goldman Lleni Pach , Ballivian Liliana , Melgar Ernesto 
Published: January 2020

Abstract
Serum proteins were fractionated by thin-layer gel-filtration on Sephadex G-200, and the content of macroglobulins (19S fraction) was determined in 137 samples from apparently healthy subjects of different ages. The relationship between amount of 19S fraction relative to total protein was found to vary widely with age. This variation has to be considered when the method is used for clinical purposes.
Pediatric Xylose Absorption Test: Measurements in Blood Preferable to Measurements in Urine
Authors: Hawkins K I 
Published: January 2020

Abstract
Data from 129 pediatric patients given oral xylose tolerance tests were reviewed and statistically analyzed to determine if blood concentrations are a more acceptable diagnostic tool than urinary excretion. After oral administration of D-(+)-xylose, blood xylose concentrations were measured at 0.5, 1, 2, 3, and 4 h, and a 5-h urine sample was analyzed. Urinary xylose excretion was more variable than blood concentration. The best criterion of celiac disease through blood sampling is a failure of blood xylose to increase during the first hour of the test. An age difference was observed but appears to be critical only if the patient is less than six months old: the lower limits of normal as determined at 0.5, 1, and 2 h are 10, 15, and 15 mg/100 ml, respectively, for patients less than six months old; and 15, 20, and 20 mg/100 ml, respectively, for older patients.
Quantitation of Sputum Protein by Use of the Biuret Reaction
Authors: Fields Joyce P , Chodosh Sanford 
Published: January 2020

Abstract
A simple, accurate method is described for quantitatively determining the protein content of sputum by use of the biuret reaction. Fifteen mechanically homogenized specimens were examined with the biuret reagent described by Rosenthal and Cundiff, and the results compared with those obtained by the microKjeldahl technique. Over a range of 542 to 1917 mg of protein per 100 ml, the techniques correlated significantly. Difficulties with deproteinization of the sputum before nonprotein nitrogen was determined were overcome by the use of zinc sulfate and pH adjustment. The proposed method is fast and reproducible.
Automated Hydrolysis of Total Estrogens in Urine from Pregnant Women
Authors: Muir G G , Ryan M 
Published: January 2020

Abstract
This method for the hydrolysis of estrogens completes the automated analysis of estrogens in pregnancy urine described by Muir, Ua Conaill, and Ryan [Steroids 13, 719 (1969)]. Pregnancy urines can be processed from the sampling of urine to the recording of fluorescence intensity in 30 min, at a rate of 20 samples per hour. The presence of glucose does not decrease the apparent hydrolysis products.
Manual Procedure for Direct Microassay of Serum Glucose by Use of o-Toluidine, and Its Adaptation to the SMA 12/60 AutoAnalyzer
Authors: Webster W W , Stinson S F , Wong W H 
Published: January 2020

Abstract
A direct o-toluidine method for serum glucose is described as an alternative to the usual Cu—neocuproine method used with the Technicon SMA 12/60 AutoAnalyzer. Routine operation of the machine is simplified: the number of reagents and manifold lines is decreased and the dialyzer and pre-heating bath are eliminated. Deterioration of manifold tubing is minimized, while maintaining optimal machine sensitivity by adding borate and water to the reagent. Serum glucose was measured by the automated o-toluidine and Cu—neocuproine methods with similar, highly correlated results. Thus, the "normal limits" are unchanged and the same recorder graph paper may be used. A direct manual micro-method is also described, in which an anhydrous o-toluidine reagent is used. Results of manual and automated methods agree satisfactorily.