bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptation of a Photoelectric Colorimeter to a Computer Program for Calculating and Storing Data in a Clinical Chemistry Laboratory
Authors: Mckay Donald K , Lotito Lawrence A , Seligson David , Wogrin Conrad A 
Published: January 2020

Abstract
In order to facilitate data processing in the clinical laboratory, a system was devised for colorimetric analysis in which the necessary calculations for hemoglobin measurement were performed automatically using analog and digital computer programs singly and combined. The technics described are essential steps toward an over-all system for obtaining, calculating, storing, and retrieving data in a clinical laboratory.
Comparison of Technics for Estimation of Albumin by Determination of Its Dye-Binding Capacity and by Paper Electrophoresis
Authors: Goodwin Jesse F 
Published: January 2020

Abstract
Values for serum albumin obtained by the methyl orange and 2-(4’-hydroxyazobenzene) benzoic acid (HABA) dye-absorption methods have been compared with values obtained by Spinco Procedure B paper-electrophoresis system. A good correlation of albumin values has been found by the three methods in serums with albumin/globulin ratios ranging from 0.19 to 3.00. Modifications of the dye-absorption procedures are presented which permit use of reagents ordinarily employed for automatic analyses on small numbers of specimens. A decrease in ionic strength of the methyl orange buffer tends to increase the sensitivity of this procedure. Temperature affects the HABA dye/albumin reaction. Bilirubin, free hemoglobin, and lipid interfere with both dye procedures. Means for eliminating most of these interferences have been presented. The methyl orange procedure appears to be superior to the 2-(4 -hydroxyazobenzene) benzoic acid method for estimating albumin in icteric serum and serum containing macroglobulins. Albumin values of serum containing abnormal proteins were compared with values obtained by paper electrophoresis and both dye procedures. Estimation of albumin by the two dye procedures appears to be simple, precise, and fairly specific.
Determination of Exogenous Galactose in Blood using "Specially Purified" Glucose Oxidase
Authors: Waldstein Sheldon S , Dubin Alvin , Newcomer Albert , McKenna Charles H 
Published: January 2020

Abstract
A method is described for the determination of exogenous galactose in blood by a modification of the Nelson-Somogyi hexose procedure in which glucose oxidase is used to eliminate interfering glucose. The use of "specially purified" glucose oxidase (SPGO) achieves low, regular blanks and satisfactory replicates, and enhances accuracy, in contrast to the results obtained with crude enzyme preparations. The ready availability of SPGO makes the method satisfactory and practical for the clinical laboratory.
False Positive Reaction Due to Methocarbamol in the Screening Test for Vanilmandelic Acid (VMA)
Authors: Campbell D J , Sherbaniuk R , Rigby J 
Published: January 2020

Abstract
Methocarbamol, a widely prescribed muscle relaxant, gives a positive result for increased vanilmandelic acid excretion with the useful screening test devised by Gitlow for evidence of pheochromocytoma. Evidence for the presence of this drug can be obtained from a positive color reaction with the 5-hydroxyindoleacetic acid test, used in the screening for carcinoid tumor.
A Colorimetric Method for Determination of Serum Chloride
Authors: Schoenfeld R G , Lewellan C J 
Published: January 2020

Abstract
A procedure is outlined for the determination of body fluid chloride levels from as little as 0.2-ml. of fluid. The results are highly reproducible and compare very favorably with the widely used method of Schales and Schales. The color produced is quite stable, and the interference of extraneous compounds has been found to have no effect on the accuracy of the method.
Direct Automated Determination of Glucose by a Glucose Oxidase-Peroxidase System
Authors: Getchell Gloria , Kingsley George R , Schaffert Roscoe R 
Published: January 2020

Abstract
A simple, accurate, automated method for the determination of glucose in plasma, urine, and spinal fluid, which does not require dialysis or protein-free filtrates is presented. Only unusually high uric acid levels in the plasma interfere with the procedure described.
Evaluation of Procedures for Urinary Calcium
Authors: Fales Frank W 
Published: January 2020

Abstract
In a comparative study of urinary calcium methods, many of the recently proposed procedures proved either impractical or invalid in our hands. A preliminary isolation of the calcium as the oxalate, followed by perchloric acid oxidation of the oxalate seemed to be the simplest procedure whereby urinary calcium could be put in a state suitable for chelometric titration. The isolated calcium could also be titrated with considerable precision and accuracy by a modified procedure with a derivative automatic titrator which is available commercially.
It was suggested from our observations that too little attention has been directed towards the problems imposed by the occurrence of calcium precipitates in urine. An untreated 24-hr. urine specimen is not suitable for direct analysis of calcium by chelometric titration, by colorimetric analysis, by emission flame photometry, or by atomic absorption flame photometry because these methods do not give a true measure of the calcium in the precipitate. Boiling for 5 min. with 1 part concentrated nitric acid to 25 parts urine proved a suitable means for completely dissolving the calcium precipitate.
Enzymatic Method for Determination of Vanillyl Mandelic Acid
Authors: Rosano Carmen L 
Published: January 2020

Abstract
An enzymatic method is described for the measurement of vanillyl mandelic acid (VMA). The method utilizes an L-mandelic acid dehydrogenase preparation from Pseudomonas fluorescens A-312 to catalyze the transformation of VMA to vanillin. The method is specific for VMA because only the final product, vanillin, will absorb maximally at 350 mµ. The results compare favorably with the method of Pisano et al.(2).
Complexometric Titration of Calcium and Magnesium by a Semiautomated Procedure
Authors: Jones James D , McGuckin Warren F 
Published: January 2020

Abstract
A semiautomatic procedure for the direct estimation of both serum calcium and magnesium is described. The indicator used, Eriochrome blue SE (EBSE), has the advantage of stability and freedom from interference by naturally occurring substances. The procedure requires 3-5 min. per sample and is very reproducible. The values obtained agree with those obtained by back-titration of excess chelator and are consistently 0.3 mg./100 ml. less than those obtained by a standard oxalate precipitation method.
Use of Halogenated Acetates and Formaldehyde as Plasma Additives in Inhibiting Heat Denaturation of Plasma Proteins
Authors: Dawson Donald , Zajtchuk Rostik , Allen J Garrott 
Published: January 2020

Abstract
Halogenated acetates alone and in combination with dextrose and formaldehyde will protect against heat denaturation of plasma proteins even when plasma is heated for 10 hr. at 60°. Application of this principle would afford reclamation of plasma from outdated blood bank blood.
Changes in protein patterns were observed by paper electrophoresis. Other measurements of denaturation were pH, absorbance at 610 mµ, and viscosity. The chemical reaction between the additives and plasma are considered, and estimations of toxicity are given.
Spectrophotometric Determination of Microgram Quantities of Copper in Biologic Materials
Authors: Stoner Ramon E , Dasler Waldemar 
Published: January 2020

Abstract
A procedure for the determination of microgram quantities of copper in biologic material is described. The sample is wet-ashed with a nitric acid-perchloric acid mixture. The copper is extracted from an alkaline solution of the ash with a solution of diphenylcarbazide in benzene. Absorbance of the red complex is read at 540 mµ. The copper in as little as 0.5 ml. of serum can be determined and the method is suitable for routine determinations. The use of microcells makes possible the analysis of 0.1 ml. of serum.
Cystine in Human Serum Proteins
Authors: Reiner Miriam , Sullivan Michael X 
Published: January 2020

Abstract
1. The amount of cystine was determined in a number of serum protein fractions separated by the procedure of E. J. Cohn. In albumin, the average value was 6.40 per cent for cystine; for γ-globulin the average value was 1.94 per cent; the other fractions tested were mixtures and varied according to the different globulins present. Globin from human hemoglobin contained 1.90 per cent cystine.
2. Separated fractions from three types of multiple myeloma cases have been presented showing abnormal fractions in the α-, β-, and γregions. The percentage of cystine was determined, and except for the fraction from the "gamma" type of myelomas, which contained 6.15 per cent cystine, the anomalous protein fractions contained about the same amount found in separated fractions of normal serum.
Urinary Peptides
Authors: Balikov Bernard , Castello Robert A 
Published: January 2020

Abstract
A simple method for the assay of urinary peptides has been presented. This method involves the reaction of a biuret reagent on a tungsticacid filtrate of Permutit-treated urine. Some possible interfering substances have been investigated and the precision of the method has been determined. Using this procedure, normal values have been assessed for adults on 24-hour urine collections.
Quantitative Nephelometric Microdetermination of Alpha-Globulins in Serum and Cerebrospinal Fluid
Authors: Saifer Abraham , Zymaris Michael C 
Published: January 2020

Abstract
1. A micronephelometric method is presented for the quantitative determination of total α-globulins in both serum and cerebrospinal fluid. The method is based on the relatively specific interaction of this protein fraction with the cationic detergent, Octab, at pH 6.65 in collidine-NaCl (.08M) buffer.
2. The various Cohn's protein fractions (Method 6) (25) were investigated with the nephelometric procedure. In comparison with normal serum, Fractions IV-6, IV-1, and IV-4, respectively showed the greatest detergent reactivity per milligram of α-globulin.
3. The variations of such factors as the concentrations of reagents, protein/detergent ratio, and salt concentration were reinvestigated.
4. Analysis of 14 normal and 33 pathologic sera gave excellent checks with the total α-globulin values obtained with the Tiselius electrophoretic method.
5. Application of the procedure to the analysis of the α-globulin content of cerebrospinal fluid required the addition of standard serum to 0.5-ml. aliquots of spinal fluid for stoichiometric results.
International Biochemical Trial 1954
Authors: Wootton I D P 
Published: January 2020

Abstract
There are two conclusions to be drawn from this trial. In the first place, this problem is universal and no country taking part maintains an acceptable standard of laboratory precision. Secondly, inspection of Fig. 1 shows that the ratio 37B/37A is significantly more constant for most constituents than are the corresponding absolute values. This implies that laboratories can compare two solutions more accurately than they can determine the absolute value of a constituent. It follows that estimations should be made whenever possible by comparing an unknown with a standard solution, a measure that would immediately eliminate one source of error.
Clinical Chemistry Work-Load Control Factors
Authors: Finch Edmund P , Owen Seward E , Byers Walter E 
Published: January 2020

Abstract
An analytic study of work-load factors in clinical chemistry shows that there are many elements involved. An average of 6.3 to 6.5 tests per man hour were obtained when clinical chemistry and urinalyses were combined. For clinical chemistry alone the tests per man hour averaged 3.1 in a hospital servicing patients with chronic diseases and 4.7 in a general hospital. The breakdown of a standard laboratory man hour in clinical chemistry included 49.3 minutes for the collection and determinative tests; the remaining time included vacations, training, personnel needs, nontechnical duties, and other items.
Activation of the Kinin-Forming System during Therapy with Cyclophosphamide
Authors: Cuschieri A 
Published: January 2020

Abstract
Venous blood kininogen is significantly decreased during therapy with cyclophosphamide in cases of advanced breast cancer. The maximum decrease in plasma kininogen coincided with onset of maximal leukopenia in the peripheral venous blood. In vitro studies showed that both human whole blood and mononuclear cell suspensions liberate free kinin when incubated with cyclophosphamide, but plateletfree human plasma does not. Evidently, the kinin-forming system is activated during therapy with cyclophosphamide, and this may account for some of its reported side effects. The in vitro studies suggest that this activation results from damage to peripheral blood leukocytes by the cyclophosphamide, with the release of intracellular proteases.
Differing Methodology and Equations Used in Quantitating Immunoglobulins by Radial Immunodiffusion—A Comparative Evaluation of Reported and Commercial Techniques
Authors: Berne Bernard H 
Published: January 2020

Abstract
Differing methods of plotting have been used to describe the results of radial immunodiffusion (RID). Two, logarithm of antigen concentration (log c) vs. precipitin-ring diameter (d) (Fahey) and log c vs. area (A or d2) (Mancini), are linear while rings are enlarging. Another, c vs. A (or c vs. d2), becomes linear when enlargement ceases at equivalence (Mancini). Because of methodological inaccuracy, I could not experimentally determine whether log c = d or log c = d2 is appropriate; either one or both semilogarithmic graphs may be linear as precipitin circles enlarge. I could confirm the c = d2 linearity at equivalence. Because smaller circles cease growth first, intermediate readings produce plots that are partially curved and partially straight. Commercial RID plates produce linear and curved plots of log c vs. d and of c vs. d2. They often create too small a diameter range for great accuracy. I conclude that semilogarithmic plots are of questionable value. For greatest accuracy plates should be designed for measurement at equivalence. At this time, a straight-line graph of c = d2 will include a maximal diameter range.
Simultaneous Automated Estimation of Noradrenaline and Dopamine in Brain Tissue
Authors: Waldmeier P , De Herdt P , Maitre L 
Published: January 2020

Abstract
A method is described for the simultaneous automated fluorometric estimation of noradrenaline and dopamine in brain extracts. It is based on a slight modification of the automated method for dopamine published recently. Interference of noradrenaline in the estimation of dopamine, and vice versa, is low (0.8 and 1.4%, respectively). Interferences of other catechols and related compounds have also been studied. Samples can be processed at a rate of 30 per hour, and the limit of sensitivity for both amines is about 2 ng/ml of brain extract.
Relative Affinity of Hemoglobin S and Hemoglobin A for Carbon Monoxide and Oxygen
Authors: Rodkey F Lee , O'Neal John D , Collison Harold A , Uddin David E 
Published: January 2020

Abstract
The relative affinity constants of hemolysates from individuals with hemoglobins A, S, or AS have been measured at 37 and 26 ° C. Observed values of all hemoglobin types were the same at both temperatures, K37 = 230, K26 = 296. Control measurements on whole blood containing Hb A gave values of K37 = 222. The small but significant difference between K37 values measured in whole blood and in hemolysates may be a result of the greater increase of MetHb in the hemolysates during the in vitro equilibration.
Statistical Quality Control and Routine Data Processing for Radioimmunoassays and Immunoradiometric Assays
Authors: Rodbard David 
Published: January 2020

Abstract
Numerous methods are available for the graphical display of radioimmunoassay dose—response curves, for curve-fitting and dose interpolation, for statistical quality control, and for automation and computerization of data processing. The relative merits of these approaches are discussed. Minimal requirements for radioimmunoassay data-processing systems are presented. The features of an "ideal" system are discussed.
Evaluation of an Enzymatic Procedure for Determination of Serum Cholesterol with the Abbott ABA-100
Authors: Witte David L , Barrett II David A , Wycoff Delane A 
Published: January 2020

Abstract
A previously reported direct enzymatic method for cholesterol [ Clin. Chem. 20, 470 (1974)] was critically evaluated in the clinical laboratory. Other methods compared to this enzymatic procedure were: (a) the manual Abell—Kendall procedure, giving a regression slope (proportional sensitivity) of 0.998 and a negative bias of 9.7 mg/dl in the enzymatic procedure; (b) Lipid Research Clinic procedure, giving a regression slope of 1.005 and a negative bias of 8.8 mg/dl in the enzymatic procedure; and (c) the SMA 12/60 (Technicon) method, giving a regression slope of 0.881 and a negative bias of 20.8 in the enzymatic procedure. Replicate analyses of pooled serum by the enzymatic procedure demonstrated the following inter-run precision: mean = 178 mg/dl, SD = 4 mg/dl, CV = 2.2%. Bilirubin caused a slight positive interference (1 mg of bilirubin per deciliter appears as 1-2 mg of cholesterol). Hemolysis, lipemia, and a series of steroid drugs caused no interference. A group of 465 normal subjects was tested by the enzymatic procedure. This population had a mean cholesterol of 203 mg/dl. The 2.5 percentile was 130 mg/dl, and the 97.5 percentile was 316 mg/dl.
New Method for Determination of Aminolaevulinate Dehydratase Activity of Human Erythrocytes as an Index of Lead Exposure
Authors: Tomokuni Katsumaro 
Published: January 2020

Abstract
I describe a new method for measurement of aminolaevulinate dehydratase (EC 4.2.1.24) activity of human erythrocytes. In this method, the amount of substrate δ-aminolevulinic acid consumed (instead of the amount of porphobilinogen formed) is determined colorimetrically. In the incubation mixture, the δ-aminolevulinic acidpyrrole produced by the condensation of δ-aminolevulinic acid with ethyl acetoacetate is separated from porphobilinogen by extraction with ethyl acetate, without resorting to ion-exchange column chromatography. The pyrrole-containing extract is treated with a modified Ehrlich's reagent. Activity of the enzyme is expressed as micromoles of δ-aminolevulinic acid consumed per minute per liter of erythrocytes. Enzyme activity is more accurately estimated by the present method than by the usual method in which porphobilinogen is measured.
Evaluation of a Gilford "Automatic Enzyme Analyzer" Modified to Assay 60 Samples per Hour
Authors: Morell Samuel A , Bach Daniel A , Ayers Valborg E 
Published: January 2020

Abstract
A Gilford 3400 Automatic Enzyme Analyzer has been modified to assay 60 samples per hour in modes 1 and 2 (28 and 61 seconds of incubation) or 30 samples per hour in mode 3 (187 seconds of incubation). The calculation cycle was reduced threefold to print activity based on ΔA/20 s, rather than ΔA/60 s. Linear ranges at 30 and 37 °C for lactate dehydrogenase, aspartate aminotransferase, and alkaline phosphatase were determined with control sera at rates of 60 samples per hour and for creatine kinase activated by dithiothreitol at 30 samples per hour. AutoAnalyzer end-point assays of patients' sera were correlated with the Gilford U/liter values. Application of the Micromedic pipette to the Gilford AEA system provided a convenient mean to study the linear range, precision, and accuracy of an enzyme assay.
Use of a Laser-equipped Centrifugal Analyzer for Kinetic Measurement of Serum IgG
Authors: Buffone Gregory J , Savory John , Cross R E 
Published: January 2020

Abstract
Use of a visible laser in an Aminco "Rotochem" centrifugal analyzer enables light-scattering measurements to be made with this instrument. The modification is technically simple, inexpensive, and requires no fundamental changes in basic instrument design. The laser-modified analyzer has been applied to the measurement of IgG in serum. A two-point kinetic analysis is used to quantitate IgG from a standard curve: protein concentration vs. change in intensity of the scattered light during a fixed time interval. Fourteen 20-µl samples can be simultaneously determined in 1.9 min. No sample blank corrections are required. Within-run precision studies, based in each case on 56 replicate measurements, yielded coefficients of variation of 3.8% and 4.8% for normal and abnormal pools, respectively.
Automated Method for Determining Serum Thiocyanate, to Distinguish Smokers from Nonsmokers
Authors: Butts William C , Kuehneman Martha , Widdowson Graham M 
Published: January 2020

Abstract
A chemical test to distinguish smokers and nonsmokers is important in many epidemiologic studies. We have developed an automated method for determining serum thiocyanate by use of the reaction between thiocyanate and ferric ions to form a colored complex. Our data show that this method distinguishes cigarette smokers and nonsmokers: of 197 healthy individuals studied, 1.8% false-positive and 6.7% false-negative results were obtained when 85 µmol of SCN- per liter was the critical value used to distinguish the two populations.
Separation and Quantitation of Coproporphyrin and Uroporphyrin in Urine
Authors: Sobel Charles , Cano Carlos , Thiers Ralph E 
Published: January 2020

Abstract
Coproporphyrin and uroporphyrin are separated from urine and from each other by absorption onto, and selective elution from, an anion-exchange resin. The two compounds are separated by using solvents differing in both polarity and pH. The porphyrins are then quantitated with an Aminco-Bowman Spectrophotofluorometer equipped with an ellipsoidal mirror and a red-sensitive photomultiplier tube. Porphyrins can be determined in 1 ml of urine from a normal individual.
Computer Simulation and Optimization, as Exemplified by the Enzyme-Coupled Aminotransferase (Transaminase) Assays
Authors: London Jack W , Yarrish Robert , Dzubow Leonard D , Garfinkel David 
Published: January 2020

Abstract
We have constructed a computer model, based on experimental data and the known properties of the enzymes involved, of the aspartate aminotransferase and alanine aminotransferase assays by the coupled-enzyme procedure of Henry et al. [Amer. J. Clin. Pathol. 34, 381 (1960)] to assay sera from normal persons and persons with liver disease or myocardial infarct. Observed inhibitions of aminotransferase activity were included in the models. When the computer models are combined with an optimization procedure, substrate concentrations that result in maximum enzyme activity for individual sera are obtained. Aminotransferase activity is not much affected by rather large changes in these concentrations around the optimum. The optimal concentrations we computed are close to those currently accepted. The computer methods involved may be applied to other assays, and factors other than reagent concentration may be optimized.