bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptation of the Zak-Epstein Automated Micromethod for Serum Iron to Determine Iron-Binding Capacity and Urinary Iron
Authors: Kunesh Jerry P , Small Larry L 
Published: January 2020

Abstract
An automated method has been developed for determining serum iron-binding capacity and urinary iron as well as serum iron. After preliminary preparation, the sample is treated with ascorbic acid in hydrochloric acid to release and reduce protein-bound iron, then singly dialyzed into an acetate buffer and reacted with 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline) to form a pink color proportionate to the amount of iron present. The sample passes through a 15-mm flow cuvet and is read at 537.5 nm, with the range expander set at either 2x or 4x.
Determination of Diazepam (Valium) Concentrations in Serum by Gas—Liquid Chromatography
Authors: Foster Lowell B , Frings Christopher S 
Published: January 2020

Abstract
A simple, rapid, and precise gas chromatographic method for determination of serum diazepam concentrations is described. Two milliliters of serum is extracted with chloroform, and the extract is concentrated and injected into a gas chromatograph. Of the many drugs and serum samples tested, none interferes with the determination of diazepam.
Simultaneous Spectrophotometric Determination of Glutethimide and Barbiturates
Authors: Dain David W , Trainer Thomas D 
Published: January 2020

Abstract
A simple, rapid, quantitative method for the simultaneous analysis of barbiturates and glutethimide (2-ethyl-2-phenylglutarimide) is described. The procedure involves a single chloroform extraction from a sample buffered at pH 7.4 and requires less than an hour.
Nomogram for Calculation of Concentration for Colorimetric Systems in which Absorbance Decreases Linearly as Concentration Increases
Authors: Gindler E Melvin 
Published: January 2020

Abstract
A nomogram is presented for use in calculating concentrations for colorimetric systems having an inverse linear relationship between absorbance and concentration. An example is given of its use for the calculation of glucose concentration. The nomogram is sufficiently accurate for clinical use, and can be rapidly used.
A Semiautomated Method for Determining Amylase Activity in Serum and Urine
Authors: Lott John A , Mercier Joan E 
Published: January 2020

Abstract
Serum or urine is incubated at 50°C with a substrate containing dextrin. The endogenous glucose and reducing sugars liberated from the substrate by amylase are separately determined on the AutoAnalyzer by use of alkaline potassium ferricyanide. Optimum conditions and limitations were evaluated. The method is compared to those of Henry and Chiamori (Somogyi) and Fishman and Doubilet. Normal values for serum and urine are presented.
Disappearance of Glutathione from Serum or Hemoglobin Solutions
Authors: Sass Martin D 
Published: January 2020

Abstract
Glutathione disappears as a soluble, nonprotein component after it has been added to serum, either in the reduced (GSH) or oxidized (GSSG) form. When GSH is added to serum it is rapidly oxidized to GSSG by some dialyzable component of serum. Glutathione is lost because of interaction of serum proteins with the GSSG formed in this manner or added directly. A similarly rapid loss of glutathione occurs in the presence of hemoglobin only if acetylphenylhydrazine is also present. This loss of glutathione in the presence of a redox drug is the result of a direct interaction between GSH and hemoglobin, in contrast to the reaction occurring in serum. The implications of these findings for hematologic disease are discussed.
Detection of Atypical Cholinesterase by an Automated pH Stat Method
Authors: Ashby Thomas M , Suggs Joseph E , Jue Danny L 
Published: January 2020

Abstract
Plasma pseudocholinesterase has no known physiological role but is essential for the rapid degradation of succinylcholine, a muscle relaxant used in surgical procedures. Depression of effective enzyme concentrations as a result of hepatocellular disease or exposure to anticholinesterase agents will increase the patient’s sensitivity to succinylcholine and prolong postoperative apnea. Synthesis of this enzyme is controlled by an autosomal gene with multiple variant alleles; individuals phenotypically homozygotic for one of these variants will have either qualitatively "atypical" pseudocholinesterase with decreased activity or no enzyme at all, and will thus be more sensitive to succinylcholine. The automated pH stat system described here detects atypical cholinesterase by measuring the degree of inhibition of butyrylcholine hydrolysis by dibucaine. The sensitivity and reproducibility of this technique equals that of standard spectrophotometric methods and its speed is comparable to that of the most rapid screening tests. A family pedigree is also presented, exemplifying a rare genotype in which two siblings are double heterozygotes for "atypical" and "silent" alleles.
Automation of a Quantitative Immunochemical Microanalysis of Human Serum Transferrin: A Model System
Authors: Eckman Irving , Robbins John B , Van den Hamer C J A , Lentz John , Scheinberg I Herbert 
Published: January 2020

Abstract
The quantitative immunochemical determination of human serum transferrin was automated with a 100-µl sample. The estimated standard deviation from the true value was 7.9 mg/100 ml in 21 samples of serum, which had transferrin concentrations of 139-325 mg/100 ml.
A Bench-Top, Automated, High-Resolution Analyzer for Ultraviolet Absorbing Constituents of Body Fluids
Authors: Pitt W Wilson , Scott Charles D , Johnson Wayne F , Jones Guy 
Published: January 2020

Abstract
An automated, high-resolution chromatograph capable of separating as many as 150 ultraviolet-absorbing molecular constituents of body fluids has been previously developed. A smaller, improved version of this analyzer, which uses only one-eighth of the previously required quantity of ion-exchange resin, sample, and eluant, is described. Analysis time has been decreased from 40 to 20 h. A prototype system of this analyzer, which will fit on an ordinary laboratory bench top, has been built and is now being tested. The small prototype analyzer uses a folded, 0.22-cm ion-exchange column for separation and a recently developed dual-beam, dual-wavelength, uv-flow photometer for detection. A unique device has been developed to generate the buffer concentration gradient used in eluting the ion-exchange column. Analyses of body fluids with this prototype are comparable to those achieved with the larger analyzers.
Automated Simultaneous Determination of p-Acetylaminohippurate and Inulin in Serum
Authors: Looyé A 
Published: January 2020

Abstract
An automated determination of p-acetylaminohippurate in serum is described. It is combined with an existing procedure for determining inulin to give a simultaneous method. The same manifold can also be used to determine p-aminohippurate in combination with fructose by omitting hydrolysis. The results of automated and manual determination are compared. Recoveries of p-acetylaminohippurate and p-aminohippurate added to serum were quantitative.
Chemical versus Spectrophotometric Determination of Bilirubin in Amniotic Fluid, and the Influence of Hemoglobin and Metheme Pigments
Authors: Kapitulnik J , Kaufmann N A , Blondheim S H 
Published: January 2020

Abstract
Methemoglobin and methemalbumin markedly diminish the measurements by spectrophotometry of the change in absorbance at 450 nm (ΔA450) in amniotic fluid but do not affect the chemical (diazo) determination of bilirubin. The converse was true of hemoglobin. In 72 of 82 specimens there was no gross contamination of amniotic fluid with these pigments and the two types of bilirubin determination agreed well (r = 0.98, p&lt;0.001) when a slight modification of the Malloy-Evelyn method was used (1 volume of amniotic fluid was diluted to 3 volumes before addition of reagents). In the other 10 cases the presence of metheme pigments significantly decreased the ΔA450, but in none of the 82 specimens was there sufficient free hemoglobin present to depress significantly the results of the chemical determination, although it can do so if enough is present.
Plasma Vitamin A Assay by Fluorometry and Use of a Silicic Acid Column Technique
Authors: Garry Philip J , Pollack J Dennis , Owen George M 
Published: January 2020

Abstract
We investigated a new procedure in which silicic acid column chromatography and fluorometry are used to assay plasma vitamin A. Using tritium-labeled vitamin A acetate and vitamin A alcohol as radioactive standards, we identified two fluorescent components in plasma extracts chromatographed on silicic acid columns. One unidentified fluorescent component was eluted first with hexane or petroleum ether. Vitamin A, the second fluorescent peak, was quantitatively eluted with isopropanol. The isopropanol eluates could be immediately assayed fluorometrically without further treatment. The unidentified compound was sensitive to ultraviolet irradiation, which destroyed it slower than vitamin A is destroyed. Values correlated well for plasma vitamin A concentrations, determined by this procedure and by the Neeld and Pearson modification of the Carr-Price colorimetric method (r = 0.871). By our technique, we found 34 µg of vitamin A per 100 ml of plasma in 778 preschool children.
Origin of the Lag Phase of Continuous-Flow Analysis Curves
Authors: Thiers Ralph E , Reed Allen H , Delander Karen 
Published: January 2020

Abstract
Physical and mathematical models are presented that account for the lag phase in the curves of transition between steady states in continuous-flow analysis. Experimental conditions are described that produce pure lag-phase curves, separated from the exponential phase with which they are combined in routine practice. The data quantitatively support the expectations from the models, and provide a means for measuring interslug transfer of fluid in bubbled streams. Others observed earlier that lag phase is associated with the bubbled stream and the dialyzer, whereas the exponential phase is associated with nonbubbled streams and debubbler [Clin. Chim. Acta 27, 421 (1960)]. Our theory and experiments confirm these earlier observations, and may provide deeper understanding of the processes involved in, and design requirements for, continuous-flow analysis.
Practical Aspects of a Measurement Technique for Calcium Ion Activity in Plasma
Authors: Radde I C , Höffken B , Parkinson D K , Sheepers J , Luckham A 
Published: January 2020

Abstract
We have evaluated the effects of the following on ion-specific electrode measurement of calcium ion activity in plasma: blood or plasma was stored in various ways for various periods of time, or exposed to air, or small amounts of heparin were added to the blood. Blood may be stored for as long as 120 min at room temperature before calcium ion activity changes measurably, but plasma stored for 20 min already has a slightly increased pH and decreased Ca ion activity. If plasma is frozen or refrigerated anaerobically after being collected, calcium ion activity is not measurably altered, but storage at room temperature is not suitable. If as much as 30 USP units of heparin is added per milliliter of blood and the blood is exposed to air for 1 min, calcium ion activity is unaltered, which allows rapidly processed samples to be used. Therefore, blood obtained by heel- or finger-prick may appropriately be used to measure calcium ion activity, particularly in newborns and infants.
Formation and Stabilities of Free Bilirubin and Bilirubin Complexes with Transition and Rare-Earth Elements
Authors: Velapoldi Rance A , Menis Oscar 
Published: January 2020

Abstract
We investigated complexes formed between bilirubin and transition or rare-earth elements, and their relative stabilities. Relative rates of complex formation were analogous to metalloporphyrin and metal complex stabilities, according to the Irving—Williams series. Transition metals that formed strong, square planar complexes caused rapid bilirubin degradation. Iron(II) was oxidized to iron(III) in the bilirubin complex. Of the lanthanide complexes, only samarium(III) showed covalent bonding tendencies. Comparative molar absorptivities were calculated for several of the metal— bilirubin complexes. The stability of bilirubin in several solvents and under various experimental conditions is reported. At room temperature, bilirubin photooxidizes to biliverdin on exposure to laboratory light.
Automated Determination of Urinary Inorganic Sulfates with the "AutoAnalyzer"
Authors: Dieu J P 
Published: January 2020

Abstract
A turbidimetric method for inorganic sulfates in urine, based on the precipitation of barium sulfate, is adapted to the AutoAnalyzer. Coating of the flowcell with BaSO4 is avoided by an inter-sample air rinsing. Sampling rate is 40/h.
Separation and Identification of Urinary Constituents by Use of Multiple-Analytical Techniques
Authors: Mrochek J E , Butts W C , Rainey W T , Burtis C A 
Published: January 2020

Abstract
High-pressure anion-exchange chromatography with gradient elution has been used to resolve ultraviolet-absorbing constituents from normal and pathologic specimens of human urine. We have identified 50 of these constituents by using multiple-analytical techniques. Ultraviolet spectral maxima, gas chromatographic methylene unit (MU) retention values (for trimethylsilyl derivatives), and the major mass spectral peaks are reported for each of the identified compounds.
Application of Fe(II)-5-Pyridyl-Benzodiazepin-2-ones to the Automated Determination of Plasma or Serum Glucose
Authors: Klein Bernard , Lucas Lois B 
Published: January 2020

Abstract
A new coupled redox reaction, developed for the determination of glucose content of plasma or serum, has been adapted to automated operation. Resuits obtained by the automated and manual versions of the technique agree well. The glucose procedure has been combined with an automated urea nitrogen technique, to enable both constituents to be measured simultaneously.
A Manual and Automated Procedure for Measuring Serum Cholinesterase Activity and Identifying Enzyme Variants
Authors: Garry Philip J 
Published: January 2020

Abstract
A simplified manual and automated method is described for measuring serum cholinesterase activity and identifying the homozygous "usual," heterozygous, and homozygous "atypical" forms of the enzyme. With butyrylthiocholine as substrate at pH 7.4, the activity is determined in two 0.05 mol/liter buffer systems, Tris and phosphate. The "usual" enzyme has the same activity in both buffer systems. The phosphate buffer inhibits the heterozygous enzyme about 13% and the "atypical" enzyme about 43% relative to its activity in Tris buffer. The range of normal serum cholinesterase values (measurements on plasma from 1842 preschool children) is 2.10 to 5.25 U (mean, 3.67 U). In this population, 3.28% of the Caucasians, but only 0.29% of the Negroes, were heterozygous for the trait.
Automated Procedure for Simultaneously Measuring Total Globulin and Total Protein in Serum
Authors: Savory John , Heintges M Geraldine , Sobel Robert E 
Published: January 2020

Abstract
An automated continuous-flow procedure has been developed for simultaneously measuring total serum protein and globulin. The method for total protein is a minor modification of an existing automated method in which the biuret reagent is used. Total globulin is measured by reaction with glyoxylic acid, and standardized with N-acetyltryptophan. An empirical factor relating concentration of N-acetyltryptophan to human globulin has been derived. Values for total serum globulin obtained by this new automated procedure correlate closely with values obtained by electrophoresis, but do not agree with values obtained by use of procedures involving binding of anionic dye. Recovery of gamma globulin added to serum is essentially quantitative; the day-to-day precision (CV) is 4.31%.
Urinary Estrogen Determination in Pregnancy
Authors: Howarth A T , Robertshaw D M 
Published: January 2020

Abstract
Results of an extensive trial of a quick fluorometric determination of estriol in pregnancy urine are described. The method is compared with the much more laborious one of Oakey et al. [Clin. Chim. Acta 15, 35 (1967)]. Trial of another apparently simpler method indicated it to be unsatisfactory in practice. The method described is accurate, simple, and rapid.
Isolation of Glycoproteins from Human Gastric Juice and Saliva by Density Gradient Ultracentrifugation
Authors: Denborough M A , Presser J C , Ungar Berta 
Published: January 2020

Abstract
Density gradient equilibrium ultracentrifugation has been used successfully to isolate the glycoproteins from human gastric juice and saliva. Analysis of the fractions obtained by this method has shown that blood-group substance glycoproteins are the major component of glycoprotein secretion in both gastric juice and saliva. The technique also separates intrinsic factor and the nonspecific B12-binding substance from the blood-group substance glycoproteins in gastric juice. The nonspecific B12-binding substances in both gastric juice and saliva have a similar density and appear to consist of a single family of molecules.
Direct Photometric Determination of Globulin in Serum
Authors: Goldenberg Harry , Drewes Patricia A 
Published: January 2020

Abstract
A convenient method for direct photometric determination of total globulin in serum has been developed using a one-tube, one-reagent system. The analysis is based on a variation of the Hopkins-Cole reaction, in which glyoxylic acid condenses with the tryptophan residues present in globulin to produce a purple color. In the presence of copper and under the conditions of the analysis, color intensity is proportional to serum globulin concentration. The method is standardized with either a serum control or a suitable tryptophan derivative (e.g., acetyl-DL-tryptophan). There is little or no interference from free tryptophan, albumin, bilirubin, lipemia, or mild hemolysis. The precision of the method is ±3% (95% confidence limits), and results agree with those obtained by the salt fractionation method of Wolfson et al. [Amer. J. Clin. Pathol. 18, 723 (1948)]: t = -0.88; critical t = 2.02; 95% confidence limits.
An Improved Method for Measuring Blood Concentrations of Phenylpyruvic Acid
Authors: Coburn S P , Mahuren J D , Fuller R W 
Published: January 2020

Abstract
We describe an improved determination of phenylpyruvic acid (PPA) in blood plasma by ultraviolet spectrophotometric measurement of an enol— borate complex. Sensitivity and recovery are well suited for accurate analysis in the range of 1.25 to 25 mg/liter. Sera from 10 fasting phenylketonuric subjects averaged 15.3 mg/liter (range, 4.8 to 25.0 mg/liter). A pronounced diurnal rhythm in plasma PPA, with peak concentrations occurring between noon and 6 p.m., was detected in patients with untreated phenylketonuria.
Simplified Manual Micromethod for Determination of Serum Triglycerides
Authors: Soloni Felix G 
Published: January 2020

Abstract
This rapid, simplified assay for serum triglycerides is based on the use of a more effective solvent extraction procedure, ethoxide transesterification, and color development with acetylacetone. No phospholipid adsorption step is necessary. The procedure requires less than 0.2 ml of serum, no expensive or elaborate apparatus, and 5 to 10 values can be obtained per hour, with better precision than with most existing methods. Recovery averaged 99.9%. There are practically no interferences. Results correlated excellently with those obtained by the classical Carlson-Wadström method.
Determination of Testosterone Binding Affinity, 17β-ol Androgens, and Free Androgen Index in Hirsute Women
Authors: Pohlman Carol , Chen Jeffrey C , Zorn Elinor M , Wieland Ralph G 
Published: January 2020

Abstract
Possibly the concentration of free 17β-ol androgens in blood may be more critical than the total circulating concentration in helping to explain female hirsutism. Total serum 17β-ol androgens were measured by radioimmunoassay in eight hirsute females. Testosterone binding affinity was assayed in dilute serum with use of Florisil. From this we calculated a free 17β-ol androgen index (FAI). When compared with concentrations obtained in normal menstruating females, both values were significantly elevated. Adrenocortical suppression resulted in a significant decrease in both 17β-ol androgens and FAI in the hirsute patients. Thus, we find the determination of 17β-ol androgens to be as valuable as the FAI in evaluating female hirsutism.
Increased Rate of Analysis by Use of a 42-Cuvet GeMSAEC1 Fast Analyzer
Authors: Burtis C A , Johnson W F , Attrill J E , Scott C D , Cho N , Anderson N G 
Published: January 2020

Abstract
Sample analysis rate for a GeMSAEC Fast Analyzer is directly proportional to the number of sample cuvets contained in each rotor. GeMSAEC Fast Analyzers are available having either 15-, 16-, or 30-place rotors. To increase the sample analysis rate, an advanced GeMSAEC Fast Analyzer has been designed and fabricated that uses a 42-place rotor. The 42-place rotor, in order to accommodate the increased number of cuvets, is a modified enlargement of the previously described 15-place rotor [N. G. Anderson, Science 166, 317(1969)]. The hardware of the 42-place system is fully compatible with the existing GeMSAEC computer module, and existing software used in the 15-place system has been modified for use with the 42-place system. Results obtained for various chemical and enzymatic analyses are discussed.
Programming Concepts for the GeMSAEC Rapid Photometric Analyzer
Authors: Kelley Myron T , Jansen J M 
Published: January 2020

Abstract
Programming in a modified conversational interpretive language such as FOCAL provides the flexibility that is desirable when using the GeMSAEC Analyzer to develop analytical methods. Three approaches to the problems of interfacing the GeMSAEC Analyzer to a PDP-8/I computer and the modifications required to the FOCAL language are briefly summarized. The configurations of the computers and peripheral devices are: a 4K PDP-8/I with 32K disk and X-Y plotter, an 8K PDP-8/I with two 32K disks and storage oscilloscope, and an 8K PDP-8/I with cartridge tape storage and a refreshed oscilloscope display.
High-Resolution Chromatographic System for Measuring Organic Acids in Biological Samples
Authors: Rosevear John W , Pfaff Kenneth J , Moffitt Emerson A 
Published: January 2020

Abstract
A chromatographic system for organic acids has been developed, with improved stability, resolution, and sensitivity for measuring organic anions in biological samples. A calibration mixture containing 100 nEq each of 18 organic anions was clearly resolved, with a signal-to-noise ratio greater than 100:1. The baseline was essentially flat throughout the chromatogram. With scale expansion, the sensitivity limit was about 0.2 nEq per constituent. The width of each peak at half its height was 1 to 2% of its retention time. The system could thus resolve 50 or more constituents. In chromatograms of whole blood and urine more than 40 compounds are resolved. The system is basically a liquid-liquid partition between an acidified aqueous phase on silicic acid and a gradient of nonpolar and polar solvents. Eluted organic acids are detected photometrically by mixing the column effluent with a miscible solvent containing a suitable indicator. Samples require about 6 h for complete chromatography at present.