bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Automatic, Solid-State Direct Readout for the Buchler—Cotlove Chloridometer
Authors: Zettner Alfred , Fontana Walter C 
Published: January 2020

Abstract
An automatic, solid-state direct-readout system was built for the Buchler—Cotlove chloridometer. The device, described in detail, makes it possible to decrease sample size and titration time. The speed of chloride determinations with use of this device is tripled, while precision is significantly improved.
Determination of Total Urinary Protein by Combined Gel Filtration and Automated Biuret Reaction
Authors: Doetsch Karl 
Published: January 2020

Abstract
Gel filtration was used to remove non-protein-bound substances that interfere with measurement of urinary protein by an automated version of the biuret reaction. Nearly 98% of the protein was accounted for, and accuracy and precision were acceptable. Interference from bile pigments or hemoglobin pigments can be eliminated, and specificity is increased.
A "Wash-out Pipet System" for Sampling Red Blood Cells
Authors: Stoler Richard G 
Published: January 2020

Abstract
A "Wash-Out Pipet System" is described for sampling erythrocytes in heparinized blood. Packed red blood cells are drawn into a 1.0 ml pipet, washed out of the pipet, and diluted to at least 50 ml, causing the cells to lyse. The pipet is blown dry with air and is ready for use again in less than 20 s.
Semiautomated Method for Measurement of Guanidinosuccinic Acid in Serum
Authors: Kamoun P P , Pleau J M , Man N K 
Published: January 2020

Abstract
A semiautomated method for analysis of guanidinosuccinic acid is described. To separate it from interfering guanidino compounds, it is absorbed on and eluted from an anion-exchange column. Colorimetry of the eluate was by Barrit’s [J. Pathol. Bacteriol. 42, 441 (1936)] modification of the Voges-Proskauer reaction.
Successive Determination of Na+, Cl-, and H+ Activities on the Skin Surface with Ion-Selective Electrodes
Authors: Green Marvin , Behrendt Hans , Libien Gloria 
Published: January 2020

Abstract
A method is described for the rapid sequential measurement of Na+, Cl-, and H+ activities on the skin surface with ion-selective electrodes. Rationales are given for details of technique such as temperature control, use of a conducting bridge, pH-dependence of sodium electrode performance, and the uniform electrode setting for all tests. Data on reproducibility document the precision of the method when applied to measurements on the skin surface. Reasons are given why Na+ and Cl- activity measurements on the skin require a different design and interpretation than skin pH determinations.
Spectrophotometry of Proline in Plasma and Urine
Authors: Goodwin Jesse F 
Published: January 2020

Abstract
A procedure is presented for proline quantification in serum filtrates and urine hydrolysates. Interference from primary amino acids is greatly reduced by nitrozation. After nitrozation and neutralization, proline is reacted with ninhydrin in a concentrated electrolyte solution. The resulting red proline—ninhydrin product is salted out, extracted into benzene, and measured at 520 nm. The extent and nature of interference from various amino acids have been determined, as has the effect of urinary constituents. Procedural variables have also been studied. Preliminary data are presented for urinary proline/creatinine ratios for 6-to 12-month-old infants.
Simple Automated Determination of Serum or Plasma Glucose by a Hexokinase/Glucose-6-Phosphate Dehydrogenase Method
Authors: Neeley William E 
Published: January 2020

Abstract
A simple, fast, efficient, and accurate automated method is described for determining the quantity of glucose in 50 µl of serum or plasma. A hexokinase/glucose-6-phosphate dehydrogenase reaction requiring incubation at room temperature is used. The method is specific for glucose, and is not affected by increased concentrations of endogenous chemical substances in uremic sera or by several common drugs that interfere with other glucose methods. Results of parallel assays, in which glucose oxidase and o-toluidine are used, are compared.
Nucleic Acid Concentrations in Normal Human Plasma
Authors: Kamm Richard C , Smith Albert G 
Published: January 2020

Abstract
Utilizing a simple, rapid, and inexpensive modification of a fluorometric method, we determined the normal concentrations of nucleic acids (DNA and RNA) in human blood plasma of healthy individuals. DNA concentrations (13.9 ± 3.7 mg/ liter) were in excellent agreement with those reported by other methods. However, the RNA concentrations (144 ± 22 mg/liter) we found were higher than previously reported values, possibly because ribonuclease activity is more inhibited in this fluorometric method.
Optimal Conditions for the Kinetic Assay of Serum Glutamate Dehydrogenase Activity at 37°C
Authors: Ellis Graham , Goldberg David M 
Published: January 2020

Abstract
Optimal concentrations of ammonium ions, 2-oxoglutarate, and NADH were defined for serum glutamate dehydrogenase (EC 1.4.1.2) activity at 37°C. Substrate inhibition was not observed with the last two compounds. The pH optimum in triethanolamine buffer is 7.4, and activity is inhibited by increasing the buffer concentration beyond 50 mmol/liter. Activation by ADP exceeds that promoted by L-leucine, and there is little advantage in having both present. Activity is linear with time and with enzyme concentration to a limiting absorbance change of 0.300 at 340 nm, and precision was satisfactory. Data indicate the normal range to lie between 0 and 4 U/liter.
Detection of Patients with Low Serum Cholinesterase Activity: Inadequacy of "Acholest" Method
Authors: Dietz Albert A , Rubinstein Herbert , Lubrano Tina 
Published: January 2020

Abstract
The "Acholest" test-paper method for estimating serum cholinesterase activity has been suggested as a preoperative screening test for patients potentially liable to prolonged apnea after use of succinylcholine. The method was tested on selected sera from normal persons and from patients with various hereditary variants of serum cholinesterase and results were compared to those obtained with a standard quantitative assay. The Acholest method failed to detect 12 of 20 cases at high risk of prolonged apnea after succinylcholine. It cannot therefore be considered as a suitable screening procedure.
Simplified Serum Phosphorus Analyses by Continuous-Flow Ultraviolet Spectrophotometry
Authors: Amador Elias , Urban Jackie 
Published: January 2020

Abstract
Serum phosphorus can be measured by continuous-flow uv spectrophotometry without reduction of the phosphomolybdate complex. The dilute sample is dialyzed into dilute (1 ml/100 ml) sulfuric acid, then mixed with an ammonium molybdate— sulfuric acid—"Tween 80" solution. The absorbance of the sample peaks is measured at 340 nm with a linear-absorbance spectrophotometer. Peak heights are directly proportional to concentration, because logarithmic conversion is performed within the spectrophotometer. The method obeys Beer’s law up to 10 mg of P per deciliter, and results correlate closely with those for standard methods based on reduced phosphomolybdate blue. The miniature manifold uses a 12-in. dialyzer. The sampling rate can be 60 to 120 samples per hour when a Gilford one-piece debubbler flow cell is used.
Automated Method for Screening Urine for Amphetamine and Some Related Primary Amines
Authors: Rutter E R 
Published: January 2020

Abstract
This paper describes an automated method for extracting and detecting amphetamine and some related primary amines in urine. In the technique the color reaction given by primary amines with 2,4,6-trinitrobenzene sulfonic acid is used, and is sufficiently sensitive to detect the excretion of therapeutic doses of amphetamine. Samples of 4 ml of urine may be analyzed at a rate of 20 samples per hour, and the method is suitable for inclusion in a multi-channel drug-screening system.
Some Methodological Modifications of the Technicon "SMA 12/60 AutoAnalyzer" System
Authors: Bigat Tevfik K , Saifer Abraham 
Published: January 2020

Abstract
Methodological modifications have been made in our "SMA 12/60 AutoAnalyzer" system, to improve the reproducibility and accuracy of six commonly performed procedures. These include glucose with the glucose oxidase method, albumin with the bromcresol green method, and alkaline phosphatase with the sodium thymolphthalein monophosphate method. We have also modified the composition of the reagents used in the determination of protein, inorganic phosphate, and aspartate aminotransferase. A general approach that is useful for adapting a new method to a multichannel AutoAnalyzer system is discussed.
Development of a Miniature Fast Analyzer
Authors: Burtis C A , Mailen J C , Johnson W F , Scott C D , Tiffany T O , Anderson N G 
Published: January 2020

Abstract
Design features and operation of a prototype miniaturized Fast Analyzer are described, and some results obtained with it are presented. The Analyzer occupies only one cubic foot of space. It has a 17-cuvet plastic rotor that rotates through a stationary optical system at speeds up to 5000 rpm. The resulting centrifugal force is utilized to transfer and mix a series of sample(s) and reagent(s) into the cuvets. The ensuing reactions are monitored spectrophotometrically, and the data evaluated in real time by an on-line computer. Samples (1 to 10 µl) and reagents (70 to 110 µl) are loaded into the rotor either discretely or dynamically; various rotor configurations can be used to do this. Many of the standard clinical analyses, including most of the NADH-linked enzymatic analyses, have been adapted for use with this analyzer. Precision obtained ranges from 1 to 4%. This report considers, specifically, analyses of some serum enzymes. Results show that the small analyzer possesses the previously demonstrated advantages of Fast Analyzers and, in addition, has several beneficial features arising from miniaturization.
Modified Automated Determination of 2,3-Diphosphoglycerate in Whole Blood
Authors: Atkinson Kenneth F 
Published: January 2020

Abstract
A modification is described of the automated determination of 2,3-diphosphoglycerate (DPG) in blood [Grisolia, S., et al., Anal. Biochem. 31, 235 (1969)]. Modifications in the manifold result in a sensitive, noise-free, rapid system and the modifications in the preparations of the reagents ensure stability of the diluted standards and blood samples for at least three weeks. Samples are run at the rate of 60/h and sample size can be as small as 5 µl of whole blood. The coefficient of variation of the overall determination of automated DPG and manual hemoglobin is 3.6% and the SD is ±0.77 µmol/g Hb. The normal range is 14.6 ± 2.2 (SD) µmol/g hemoglobin.
An Error-Producing Interaction in an Automated Method for Measuring Cholinesterase Activity in Blood
Authors: Ellin Robert I , Groff William A , Kaminskis Andris 
Published: January 2020

Abstract
Blood cholinesterase activity values obtained in our laboratory by the automated procedure of Levine et al. (Automat. Anal. Chem., Technicon Symp. 1965) are greater than those values obtained by a comparable manual method. This problem is caused by reaction of the standard (reduced glutathione) with the substrate (acetylthiocholine) to form acetylglutathione and thiocholine. Because thiocholine dialyzes about three times more rapidly than glutathione in the automated system and gives the same color reaction, proportionately higher activity values would be reported. Ways of correcting this problem are presented.
Rapid, Simplified Method for Measuring Total Hepatic Cholesterol
Authors: Naito Herbert K , Lewis Lena A 
Published: January 2020

Abstract
Because determinations of hepatic total cholesterol are frequently needed, an automated, continuous-flow method would be useful to have available. Hepatic total cholesterol is extracted with isopropyl alcohol in one step and the extract is then quantitatively analyzed by an accepted AutoAnalyzer procedure for serum total cholesterol. Homogenization of the tissue eliminates the use of proteolytic enzymes or KOH for the digestive process. The one-step extraction of total cholesterol with isopropyl alcohol simultaneously precipitates interfering proteins. Addition of FeCl3 color reagent to an aliquot of clear extract produces a stable color with a density proportional to the amount of cholesterol present, which can be quantitatively detected by a colorimeter and recorded on a graphic recorder. This automated method eliminates tedious, time-consuming processes, and can greatly increase the reliability and accuracy of hepatic total cholesterol determinations. This method is shown to be rapid, reproducible, and simple. The procedure is adapted for both wet tissue and lyophilized samples, the latter giving slightly more reproducible results.
Reporting Terminal for Sequential Multiple Analysis and a Positive Identification System for Serum Specimens
Authors: Kaufman James H 
Published: January 2020

Abstract
The Sequential Multiple Analysis Reporting Terminal (SMART) and the Bio-Logics Specimen Identification System have been interfaced with the SMA 6/60 and the SMA 12/60. This installation, first of its kind, accurately converts and condenses SMA output into compact, easily read reports, with concomitantly increased efficiency in serum handling and accuracy in patient identification.
Multichannel Analyzer Featuring Ultrahigh Stability Photometry: Application to Enzyme Determination
Authors: Pardue Harry L , Miller Michael M 
Published: January 2020

Abstract
An instrument system has been developed for the simultaneous photometric monitoring of multiple sample channels. Salient features of the system include ultrahigh photometric stability, random access to individual channels, electronic channel selection, wavelength selectivity among the different channels, and either manual or computercontrolled operation. The system implemented in this work consists of 10 sample channels arranged radially around a single stabilized source. It has been evaluated for the kinetic determination of alkaline phosphatase in reconstituted sera. The drift of the photometer averages less than 0.03% T (1.3 x 10-4A) per hour. Assay values for alkaline phosphatase exhibit standard deviations of 2% or less in most cases.
Comparison of Ascorbic Acid Concentrations in Whole Blood Obtained by Venipuncture or by Finger Prick
Authors: Bradley Daniel W , Maynard James E , Emery Gladys 
Published: January 2020

Abstract
Vitamin C (ascorbic acid) concentrations in whole blood obtained by finger prick or by venipuncture have been shown to be equivalent when measured by the 2,4-dinitrophenylhydrazine procedure. Whole blood obtained by either technique is stable for at least 6 h at 25°C, and for as long as 28 days when stabilized with trichloroacetic acid and stored at 4°C. Storage of whole blood at -70°C is accompanied by an initial loss (10-20%) of vitamin C; however, additional losses of vitamin C do not occur beyond the third day of storage.
Rapid Spectrofluorometric Assay for Total Bile Salts in Bile
Authors: Mroszczak Edward J , Riegelman Sidney 
Published: January 2020

Abstract
An assay is presented for total bile salts in bile. The procedure involves one precipitation and extraction step and then treatment with concentrated sulfuric acid to produce fluorescent products, which are then measured at an excitation wavelength of 470 nm and emission wavelength of 505 nm. With sodium taurocholate as the standard (fluorescence intensity of 1.00), the average fluorescence intensity of equimolar concentrations of the taurine and glycine conjugates of cholic, deoxycholic, and chenodeoxycholic acid is 1.01 (standard dev., 0.05). The average recovery of the six bile salts from pooled rat bile is 95.7% (standard dev., 8.5). The assay compares well with the established gas—liquid chromatographic and enzymatic methods, but it is simpler, faster, less costly, and just as reliable as the alternative methods.
Enzymes in Cancer
Authors: Schwartz Morton K 
Published: January 2020

Abstract
Since Warburg and his associates reported in 1924 that cancer tissue exhibits a greater rate of aerobic glycolysis than normal tissue, there have been numerous efforts to define enzymatic defects in cancer tissue. Attempts have been made to use enzyme assays in the diagnosis of cancer and in following the course of the disease. This review considers in this regard the role of organ-specific enzymes (amylase, phosphohydrolases, etc.) as well as the more ubiquitous glycolytic enzymes. The usefulness of the assay of isoenzymes in serum, as well as in tissue of cancer patients, is discussed and the role of enzymes in chemotherapy considered
AutoAnalyzer Assay for Serum Alkaline Phosphatase Activity, with Sodium Thymolphthalein Monophosphate as Substrate
Authors: Proksch Gary J , Bonderman Dean P , Griep John A 
Published: January 2020

Abstract
An automated method is described for determining alkaline phosphatase activity in serum, with use of sodium thymolphthalein monophosphate as the substrate. The system makes use of standard AutoAnalyzer components, has a simple flow diagram, and does not involve dialysis. The method has good precision, and the results correlate well with those from the manual method of which it is an adaptation
Sensitive Fluorometric Method for Determination of Quercetin in Plasma or Urine
Authors: Gugler R , Dengler H J 
Published: January 2020

Abstract
A fluorometric method is described for determining quercetin, a flavonoid compound, in plasma and urine. It is based on the formation of the highly fluorescent quercetin-tetraphenyldiboroxide complex. The excitation wavelength used is 445 nm, the emission wavelength 500 nm.
Specific Photometric Determination of 5-Hydroxyindoleacetic Acid in Urine
Authors: Goldenberg Harry 
Published: January 2020

Abstract
Udenfriend‘s nitrosonaphthol test for 5-hydroxyindoleacetic acid (5-HIAA) is subject to interference by urinary phenolic acids and drug metabolites. Studies in our laboratory have shown that the specificity and sensitivity of the nitrosonaphthol reaction with 5-hydroxyindoles can be greatly enhanced by the addition of 2-mercaptoethanol. This observation serves as the basis of a simple, improved method for the photometric determination of urinary 5-HIAA. The 5-HIAA is extracted from urine and transferred to a colorimeter tube. Treatment with nitrosonaphthol and nitrous acid results in formation of Udenfriend’s violet chromophore, which is converted to an intense blue chromophore upon addition of mercaptoethanol. Extraneous colors caused by reactive phenols and indoleacetic acid in urine are destroyed at this point by the mercaptoethanol. The intensity of the remaining blue color is proportional to the 5-HIAA concentration. Recoveries of added 5-HIAA by the proposed method are quantitative. The normal 24-hour excretion values obtained for human subjects fall in the range of 0.8 to 6.0 mg (95% confidence limits), with a mean of 3.9 mg. Drugs that produce a false positive test for intestinal carcinoid with earlier photometric methods have no effect on the new method
Application of Fe(II)-5-Pyridyl Benzodiazepin-2-ones to the Manual or Automated Determination of Serum Uric Acid
Authors: Klein Bernard , Lucas Lois B 
Published: January 2020

Abstract
A new coupled-ferricyanide-redox reaction has been developed for the manual and automated determination of serum uric acid. The 580-nm absorbance of the photometric end point, formation of the violet-blue Fe2+-5-pyridyl benzodiazepin-2-one chelate, is proportional to uric acid concentration. Replicate manual analyses are precise (CV = 1.2%) and reproducible from day-to-day (CV = 3.2%). Adapted to automated (AutoAnalyzer) operation, replicate analyses also show good precision (CV = 1.03%) as well as good day-to-day reproducibility (CV = 3.35%). Recovery of added uric acid averaged 98.5% (range: 92.7-107.5%) in the manual procedure and 99.9% (range: 96.6-103.3%) in the automated mode. Formaldehyde, commonly used to preserve uric acid solutions, has been shown to interfere with recovery analyses in the automated analyses. Results obtained by the present procedure and reference carbonate-phosphotungstate and uricase methods agree well
Increased Aspartate Aminotransferase Activity of Serum after in Vitro Supplementation with Pyridoxal Phosphate
Authors: Rej Robert , Fasce Charles F , Vanderlinde Raymond E 
Published: January 2020

Abstract
We examined the effect of pyridoxal phosphate supplementation on the apparent aspartate aminotransferase (EC 2.6.1.1.) activity of human serum. Supplementation by 25 µmol/liter effected an average increase of 16% in the results for kinetic assay. The increase was not the result of increased enzymatic or nonenzymatic blanks, and, within a small range, sample dilution had no significant effect. Part of the increase was attributable to the enzyme being protected against the loss of activity that occurs during preincubation with L-aspartate. A similar increase was not demonstrated in a two-point colorimetric method, perhaps because of the short reaction time, without preincubation, and the initial presence of both substrates in the assay. We attempted to Correlate such stimulation of aminotransferase activity and the patient’s diagnosis or treatment. Pyridoxal phosphate should be included in the reaction mixture when aspartate aminotransferase activity is being measured clinically
Computer-Controlled Instrument System for Sequential Clinical Chemical Testing. I. Instrumentation and System Features
Authors: Toren E Clifford , Carey R Neill , Cembrowski George S , Schirmer James A 
Published: January 2020

Abstract
Instrumentation and software of a computer-controlled system for analytical chemistry is described, which will: (a) automatically carry out any one of a large number of tests, (b) utilize the results of that test in conjunction with data derived from other sources as a basis to proceed to select and perform another analysis, and (c) continue in this mode by a branching sequence until the analytical potential of the specimen is exhausted. The system is programmable with user control languages that require no programming experience. The external equipment controlled by the computer in a time-sharing mode includes a sampler, a digital pipet, a digital valve, a ratemeter, and a dual-beam spectrophotometer with a programmable wavelength drive.
Kinetics of the Cholesterol-Sulfuric Acid Reaction: A Fast Kinetic Method for Serum Cholesterol
Authors: Hewitt Thomas E , Pardue Harry L 
Published: January 2020

Abstract
We studied the kinetics of the reaction between cholesterol and sulfuric acid in acetic acid-acetic anhydride medium. Results have been used to establish near-optimal conditions for the fast kinetic determination of cholesterol in serum. The reaction rate measured during the first 20 s of the reaction is proportional to cholesterol concentration. There is good agreement (&lt;2% deviation) between pseudo-first-order rate constants for cholesterol standards and sera. Recoveries of standard cholesterol added to sera range from 99% to 104% (average, 100.7%). Values for serum cholesterol by this kinetic determination tend to be somewhat lower than equilibrium values reported by local hospital laboratories. Whether bilirubin interferes depends on reaction conditions; under optimal conditions, each milligram of bilirubin is kinetically equivalent to about 1 mg of apparent cholesterol. Kinetic data are included to show how results are degraded by operating under nonoptimal conditions, and considerations involved in changing experimental conditions are discussed.