bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Portable Data Processor with Mechanical Data Output for Use with a Miniature Fast Analyzer
Authors: Johnson W F , Mailen J C , Burtis C A , Tiffany T O , Scott C D 
Published: January 2020

Abstract
The Mark I Data Processor is a system for acquiring, processing, and printing, without the aid of a computer, the results of analyses carried out in Fast Analyzers. Because it is inexpensive and portable, this system is particularly applicable for use with the newly developed miniature Fast Analyzer. It uses digital logic to correlate the signals originating at the photodetector of the analyzer with the proper cuvet position and corresponding recorder channel. The transmission pulses are converted electronically to absorbance values, which are recorded as printed dots on a data card. Vertical height on the card is proportional to absorbance, with the maximum absorbance and the absorbance span to be covered being set by calibrated potentiometers. The Mark I Data Processor has been evaluated in parallel with an on-line computer, and data obtained from it have been found to correlate with the computer-derived data.
Mechanized, Direct Digital-Control Pipette for Automation of Ultramicro Chemcial Analyses
Authors: Nishi H Harold 
Published: January 2020

Abstract
A basic direct digital-control(DDC) pipette has been developed for the automation of ultramicro chemical analysis. The new pipette is an electromechanical device, which consists of an electronic preset-indexer, a stepping motor, a screw slide assembly, a syringe barrel equipped with a dedicated displacement rod of uniform diameter. The fluid volume is measured in relation to length of the displacement rod. With the DDC pipette, one has the unique ability to control electromechanically the movement of the displacement rod in precise increments of 3.17 µm. To measure a specific volume of fluid, the number of incremental movements required by the displacement rod to equal the desired volume is dialed into decade dials. Precision studies showed that the DDC pipette was capable of measuring 1 µl of fluid with a precision better than 0.5%. With slight modifications, the basic DDC pipette can be converted into an automatic sample-diluting system.
Development of Automation of Differential Leukocyte Counts by Use of Cytochemistry
Authors: Saunders Alex M 
Published: January 2020

Abstract
Development of automation in cytochemistry is reviewed. A variety of disciplines had to be merged to accomplish the following. Samples of anticoagulated whole blood are processed chemically in a continuous-flow system having precise proportioning of reagents and exact time sequences for reactions. While red blood cells are lysed, color contrast is developed in specific white blood cells. These are counted and differentiated by their light absorption and light scattering characteristics, typically at a rate of 500-2000 per second, in an automatic electro-optical device through which the cell suspension flows. The procedure is highly reproducible because it relies on physical constants rather than human judgment and because greater replication of sample is possible in the same time.
Gas-Liquid Chromatographic Analysis for Purine and Pyrimidine Bases in Hydrolysates of Nucleic Acid
Authors: Lakings Duane B , Gehrke Charles W 
Published: January 2020

Abstract
In this fast, simple method for analysis of microgram amounts of purine and pyrimidine bases in nucleic acid hydrolysates, RNA and DNA are optimally hydrolyzed in equal volumes of trifluoroacetic acid and formic acid, heated in a closed tube at 200°C for 1.5 h (for RNA) or at 150°C for 2.0 h (for DNA). The trifluoroacetic acid and formic acid are evaporated from the hydrolysates on a hot plate at 60°C, under a stream of pure nitrogen. The resulting nucleic acid bases are then silylated with a mixture of equal volumes of bis(trimethylsilyl)trifluoroacetamide and acetonitrile at 150°C for 15 min, and analyzed by gas-liquid chromatography on a column of SE-30 on Supelcoport.
Development and Evaluation of a High-Speed Continuous-Flow Analyzer
Authors: Evenson M A , Olson M A 
Published: January 2020

Abstract
A high-speed, high-performance, continuous-flow analyzer is described that operates at two to three times the usual analysis rate without necessitating corrections of the raw data and with no decrease in accuracy or precision. At faster speeds (180-300 samples/h) inductive sample interaction (%Ii), opposite in direction to carry-over, is for the first time quantitatively measured. A correction equation for %Ii was developed, and when it is applied to raw data, the accuracy of the results are significantly improved. Operating characteristics of the high-speed analyzer are described and the desirability of automatic computer corrections is discussed for the high-speed system.
Isolation of 2-Acetamido-1-β-(L-β-Aspartamido)-1,2-Dideoxy-D-Glucose from Normal Human Urine
Authors: Rowley Barbara O’Neill , Hamilton Paul B 
Published: January 2020

Abstract
A glycopeptide was isolated from normal human urine by fractionation on a column of Sephadex G-10 and preparative ion-exchange chromatography. Elution behavior during ion-exchange chromatography in two different solvent systems, amino acids formed upon hydrolysis, and migration on high-voltage electrophoresis and thin-layer chromatography were essentially identical for this substance and for authentic 2-acetamido-l-β-(L-β-aspartamido)-1,2-dideoxy-D-glucose. A technique was developed to permit analytical-scale fractionation of individual urines followed by analysis for this glycopeptide; urine from two normal individuals contained 7 and 11 µmol of 2-acetamido-1-β-(L-β-aspartamido)-1,2-dideoxy-D-glucose per liter.
Determination of Phenylbutazone in Plasma
Authors: Jähnchen Eberhard , Levy Gerhard 
Published: January 2020

Abstract
The permanganate oxidation method for the spectrophotometric determination of phenylbutazone has been modified and optimized to permit precise assays of phenylbutazone in small plasma samples. The assay is not affected by the presence of p-hydroxyphenylbutazone, the major metabolite of phenylbutazone. Weak bases are removed in the initial extraction procedure, and weak acids such as phenobarbital, warfarin, diphenylhydantoin, salicylic acid, and sulfadiazine do not interfere in the assay.
A Statistical Model for Assessing the Need for Medical Care in a Health Screening Program
Authors: Hartz Stuart C 
Published: January 2020

Abstract
This is a statistical model (the "multiple logistic model") for pooling data from many variables into a single probability estimate that a person examined in a health screening system requires medical care. Because discrete variables are frequently studied in health screening programs, the required assumption of multivariate normality of the predictor variables related to many statistical techniques is seldom fulfilled. A computing method is given that avoids this assumption by directly assuming the appropriateness of logistic function and obtains the corresponding maximum likelihood estimates (MLE) of the unknown parameters. Fisher’s linear discriminant function (LDF) may be used to provide the initial estimates of these parameters, which are necessary for the application of the MLE computing procedure. The algorithms to estimate these coefficients are discussed for both the LDF and MLE models, and an application of these methods to a set of data is presented and other applications of this procedure are proposed
Colorimetric Determination of 2,3-Diphosphoglycerate in Whole Blood
Authors: Luisada-Opper Anita V 
Published: January 2020

Abstract
A method for determining 2,3-diphosphoglycerate (DPG) is described that has been adapted for the clinical laboratory and does not require any special equipment. For eight controls, the average value obtained by this method was 4.19 ± 0.26 µmol of DPG per milliliter of red blood cells. The procedure is simple, quick, and reliable
Radiometric Assay of Citrate Condensing Enzyme (Citrate Synthetase) in Liver Tissue and Mitochondria
Authors: Dixit Padmakar K , Cuestas Raul 
Published: January 2020

Abstract
Citrate synthetase activity was determined in samples of commercially available citrate condensing enzyme. We measured the amount of radioactive citrate formed from the condensation of carbon-14 labeled acetyl CoA and oxaloacetate. The labeled citrate was oxidized by oxidative bromination; 14CO2 evolved was collected and represented the amount of citrate synthesized. Enzyme activity as low as 10-4 µmol/min was measured reproducibly with this procedure. Results obtained with this assay compared closely with those of a widely used spectrophotometric assay in which Ellman’s SH-coupling reagent [5,5-dithio-bis-(2-nitrobenzoate)] is coupled with CoA released during the reaction. Accuracy of labeled citrate determination in the presence of labeled acetate or pyruvate was excellent. The method can be used to determine citrate synthetase activity in skeletal muscle, liver, and isolated liver mitochondria, or to study the fate of labeled citrate injected into animals.
Rapid, Sensitive, and Selective Assay for Tryptophan in Serum
Authors: Guilbault George G , Froehlich Peter M 
Published: January 2020

Abstract
We have developed a rapid, selective, and sensitive fluorometric procedure for measuring tryptophan in serum. This assay is based on the facile reaction of tryptophan with aqueous formaldehyde; the concentration of the amino acid is measured from the diminution in its fluorescence as the reaction proceeds. Compared to other assay procedures, this procedure has the advantage of being sensitive to the amino acid, but unresponsive to other indole derivatives such as tryptamine and 5-hydroxytryptamine. Concentrations of tryptophan as low as 0.5 mg/liter may be assayed in 15 min.
Determination of Total Urinary Protein, Combining Lowry Sensitivity and Biuret Specificity
Authors: Doetsch Karl , Gadsden Richard H 
Published: January 2020

Abstract
A highly sensitive method with specificity for the peptide chain backbone was developed for determination of total urinary protein. Interfering substances are removed by gel filtration and cupric ions are stoichiometrically bound to the peptide bonds of protein by the biuret reaction. Ion-exchange characteristics of the gel are neutralized, allowing protein—copper complex to be separated from excess cupric ions by a second gel filtration step. Copper bound to peptide bonds is colorimetrically determined by use of sodium diethyldithiocarbamate. Nonprotein substances do not interfere unless they simultaneously bind to protein and chelate copper. As little as 1 mg of total protein per deciliter can be determined in heterogeneous biological fluids such as urine.
Spurious Elevation of Apparent Lactate Dehydrogenase Activity Caused by Triamterene
Authors: Chainuvati T , Harinasuta U , Zimmerman H J 
Published: January 2020

Abstract
Triamterene induced spurious elevations in serum lactate dehydrogenase activity, as assayed by an automated fluorometric method; the enzyme activities were normal when measured spectrophotometrically. Solutions of the drug in normal serum or physiological saline, without addition of substrate or coenzyme, yielded high values for apparent "enzyme" activity by the fluorometric assay.
Solid-Phase Radioimmunoassay for Digoxin
Authors: Line William F , Siegel Stanley J , Kwong Anda , Frank Clifford , Ernst Roberta 
Published: January 2020

Abstract
Anti-digoxin serum was conjugated to agarose or to organo-functional glass beads. The immunoadsorbents were compared to each other and to the soluble antibody, with respect to coupling efficiency and retention of immunological activity. We found that the antisera coupled to a glass-isothiocyanate retained about 50% of its immunological activity upon attachment. This derivative was superior to one prepared by coupling to CNBr-activated agarose, in which the attached protein retained 7% of its activity; and one prepared by coupling the protein to alkylamino glass using a water soluble carbodiimide, in which the attached antiserum retained only 1.5% of its original activity.
Use of Horseradish Peroxidase in Identification of Serum Antibodies and Immune Complexes
Authors: Murphy William M , Deodhar Sharad D , Cawley Leo P 
Published: January 2020

Abstract
We made 202 examinations on specimens from 78 patients, to evaluate the application of horseradish peroxidase-labeled antisera as compared to fluorescein-labeled material in a clinical immunology laboratory. Various circulating and tissue-fixed antibodies were identified by both techniques. The horseradish peroxidase technique can be substituted for the fluorescein isothiocyanate method for the evaluation of anti-nuclear antibody and anti-mitochondrial antibody without loss of specificity or sensitivity. Although the results are comparable, fluorescein isothiocyanate appears to be slightly more sensitive in the detection of the other circulating and tissue-fixed human antibodies examined. Further refinements in preparation and technique could well lead to the fluorescein method being replaced by horseradish peroxidase staining in the future.
Rapid, Simplified Continuous-Flow Colorimetry of Serum Triglycerides
Authors: Holub William R 
Published: January 2020

Abstract
A new modified, semi-automated method for triglyceride assay is described. The sampling rate is rapid (60/h) with acceptable inter-sample wash. Color and triglyceride concentration are linearly related up to 500 mg/dl. The modifications were: heated reactions were eliminated, a short Kel-F coil was used for transesterification, arrangements were made for simultaneous debubbling and phase separating. Both comparison with another semi-automated procedure and recovery values indicate the acceptability of this proposed method for use in routine clinical laboratories.
Conditions for a Radioimmunoassay of Serum Parathyroid Hormone
Authors: McCann Daisy S , Prunty JoAnn , Rigg Gerald , Arnstein Robert 
Published: January 2020

Abstract
A radioimmunoassay for parathyroid hormone is described that circumvents some previous difficulties. Parathyroid hormone binds strongly to other serum components. Consequently, a "control" curve is set up for each specimen, the specimen consisting of serum, diluent, and radiolabel, but no antibody. Final calculations are then based on the difference between the control curve and the curve obtained by incubating serum, diluent, radiolabel, and antibody. The lack of parallelism between various sample curves makes it almost mandatory that curves derived from at least 12 dilutions of serum be included for each specimen.
Polyacrylamide-Gel Disc-Electrophoresis as a Screening Procedure for Serum Lipoprotein Abnormalities
Authors: Naito Herbert K , Wada Mitsuo , Ehrhart L A , Lewis Lena A 
Published: January 2020

Abstract
A polyacrylamide-gel disc-electrophoresis system is described that is suitable for screening sera with a wide range of lipid concentrations, and the results agree with analytical ultracentrifugation data. The lipoprotein pattern so obtained was compared with that obtained by other recognized electrophoretic procedures. Lipoprotein determinations were done by polyacrylamide gel electrophoresis, for 125 patients, to determine its merit as a clinical screening method for lipoprotein abnormalities as compared to the paper-electrophoretic method. The lipid dye and riboflavin concentration of the gels used give a background that makes it easy to detect chylomicra in the sample gel and allows for densitometric semiquantitation of the lipoprotein fractions. The method is reliable, precise, and accurate.
Automated Kinetic Spectrophotometric Assays of Enzyme Activities of Human Cerebrospinal Fluid: Methods and Reference Values
Authors: Sharpe David M , Wilcock A Ross , Goldberg David M 
Published: January 2020

Abstract
Optimum conditions with respect to pH and molarity of phosphate buffer, and the concentrations of substrates, coenzymes, and exogenous enzyme, were defined at 37°C for activity of aspartate transaminase and lactate dehydrogenase of human cerebrospinal fluid (CSF), as measured by optical kinetic assays at 340 nm. The resulting methods, and a previously published procedure for malate dehydrogenase activity applicable to human CSF, were adapted for use with an automatic reaction-rate monitor. Within-batch and between-batch precision of all methods was satisfactory, and repeated estimations in seven subjects showed good agreement. Freezing samples decreased their activity by 5 to 10%, but thereafter no further losses occurred at -20°C for as long as three months. Injection of up to 12 ml of air during encephalography had no major effect. Reference values, derived from subjects with no neurological or simple chronic degenerative CNS disease, suggested that the upper limits (in U/liter) are: aspartate transaminase, 13.5; lactate dehydrogenase, 40; malate dehydrogenase, 58.
Estimation of Norms from a Controlled Sample Survey. II. Influence of Body Habitus, Oral Contraceptives, and Other Factors on Values for the Normal Range Derived from the SMA 12/60 Screening Group of Tests
Authors: Winkelman J W , Cannon D C , Pileggi V J , Reed A H 
Published: January 2020

Abstract
Sera from 423 clinically normal men and 557 clinically normal women, ages 20 to 49, were analyzed on the "AutoAnalyzer 12/60" (Technicon Corp.). The results were grouped by sex of the subject and subgrouped according to body habitus (overweight, normal weight, or underweight), region of residence in U. S., and other variables. Among subgroups, statistically significant differences in normal range limits were sought. Notable findings include (a) lactate dehydrogenase activities tend to be lower in winter, (b) women taking oral contraceptive medications have diminished albumin and inorganic phosphorus concentrations, and (c) overweight but otherwise clinically normal individuals tend to have higher uric acid values than do healthy individuals of normal weight.
Free Calcium in Serum. I. Determination with the Ion-Specific Electrode, and Factors Affecting the Results
Authors: Ladenson Jack H , Bowers George N 
Published: January 2020

Abstract
Free (ionic) calcium in human serum was measured with a commercially available ion-specific electrode, together with a saturated-KCl salt bridge, a saturated-calomel reference electrode, and a direct-reading electrometer. Effects of sodium, potassium, and magnesium on the electrode values for calcium were assessed and a rationale demonstrated for the use of calcium standards containing 140 mmol of NaCl, 5 mmol of KCl, and 0.55 mmol of MgCl2 per liter. Trypsin, triethanolamine, and heparin bind calcium; therefore, their use is to be avoided. Variability is greatly decreased if the serum is from a fasting subject and if the collection tube is completely filled, transported on ice, and handled anaerobically. The range for free calcium for 86 apparently healthy adults was 1.175-1.375 mmol/liter when measured at 25°C. The precision (coefficient of variation) of duplicates was 0.6%; the long-term precision ≃2.0%.
Sensitive Fluorescence Monitoring of Aromatic Acids after Anion—Exchange Chromatography of Body Fluids
Authors: Katz S , Pitt W W , Jones G 
Published: January 2020

Abstract
A simple, sensitive system has been developed for detecting oxidizable compounds that are eluted from chromatographic columns. It relies upon the production of fluorescent cerium(III) by the reaction of eluted compounds with cerium(IV) solution. When coupled with a modified ultraviolet-monitored anion-exchange chromatograph, this system provides excellent resolution and sensitivity in the analytical determination of aromatic organic acids.
Homogeneous Enzyme Immunoassay for Opiates in Urine
Authors: Schneider Richard S , Lindquist Peggy , Wong Emmy Tong-in , Rubenstein Kenneth E , Ullman Edwin F 
Published: January 2020

Abstract
An assay technique, homogeneous enzyme immunoassay, is described for the quantitative determination of morphine derivatives in biological fluids. An enzyme is labeled with morphine. When the enzyme-labeled morphine is bound by antimorphine antibodies, the enzyme is rendered inactive. Free morphine competes with enzyme—morphine for antibody binding sites preventing inhibition of enzyme activity. Enzyme activity is thus directly related to the concentration of free morphine.
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Where the enzyme used is lysozyme, the assay can detect 0.5 µg of morphine per milliliter of urine with &gt;95% confidence (CV, 5.0% at 0.5 µg/ml morphine). The technique gave nearly twice as many confirmed positives as did thin-layer chromatography in a comparative study of urines from a methadone maintenance program. The immediacy of the results (assay time: &lt;1 min) permits use of the assay in hospital emergency rooms, law-enforcement facilities, and methadone treatment programs.
Use of Stable Isotopes in Measuring Low Concentrations of Drugs and Drug Metabolites by GC—MS—COM Procedures
Authors: Horning M G , Nowlin J , Lertratanangkoon K , Stillwell R N , Stillwell W G , Hill R M 
Published: January 2020

Abstract
Certain drugs in urine, plasma, breast milk, and amniotic fluid have been quantitatively analyzed in the picogram to nanogram range by selective ion detection with two gas chromatograph—mass spectrometer—computer systems: an LKB 9000/PDP 12 operated in the electron impact mode and a Finnigan 1015/PDP 8/I operated in the chemical ionization mode. With the latter system, it is possible to monitor several drugs and drug metabolites and an internal standard in a single temperature-programmed analysis. Internal standards labeled with stable isotopes are preferred for selective ion detection. Diphenylhydantoin-2,4,5-13C has been used to quantify diphenylhydantoin, and pentobarbital-2,4(6) ,5-13C has been used to quantify amobarbital, secobarbital, caffeine, meperidine ("Demerol"), and phenobarbital in 50-200 µl samples of plasma and breast milk.
Relationships among Urinary Aminoimidazolecarboxamide in Urine and Folate, and Vitamin B12 Concentrations in Serum
Authors: Harrison J W , Slade B A , Shaw W 
Published: January 2020

Abstract
Urinary aminoimidazolecarboxamide (AIC), serum folate, and serum vitamin B12 values were determined in 84 apparently healthy individuals. An automated system for determination of AIC in urine is described. Despite claims to the contrary, we found no evidence of a strong relationship between elevated (e.g., &gt;1.3 µg/mg of creatinine) AIC excretion as reflected in a casual sample of urine and folate or vitamin B12 deficiency. Urinary AIC values ranged from 0.10 to 5.20 µg/mg of creatinine. The mean for the population examined was 1.36 ± 1.02 µg/mg of creatinine.
Automated Measurement of Urinary Iodine
Authors: Garry Philip J , Lashley D Wayne , Owen George M 
Published: January 2020

Abstract
We describe a simplified, automated method for screening urinary iodine. Digestion with strong acid is avoided by dialyzing urine and then directly analyzing iodine in the dialysate with the ceric ion—arsenious acid system. This method is particularly useful for analyzing large numbers of samples without loss in precision. Urinary iodine excretions are reported for 1224 children 1 to 6 years of age.
Gas-Chromatographic—Mass-Spectrometric Determination of Urinary Acid Profiles of Normal Young Adults. II. The Effect of Ethanol
Authors: Witten Thomas A , Levine Steven P , Killian Mary T , Boyle Peter J R , Markey Sanford P 
Published: January 2020

Abstract
Urinary acid metabolic profiles of 26 healthy young adults who were maintained on a palatable standard diet for three days have been studied by combined gas chromatography-mass spectrometry. Means and standard deviations of the excretion rates of individual, identified acids were determined after the ingestion of ethanol and compared to basal values previously reported. A significant net effect of ethanol was demonstrated for only six of the acids studied: α- and β-hydroxybutyric, adipic, β-methyladipic, p-hydroxyphenylacetic, and 2,5-furandicarboxylic acids.