bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Modified Procedure for the Estimation of Total 17-Hydroxycorticosteroids (Porter-Silber Chromogens) in Urine
Authors: Liu John HC 
Published: January 2020

Abstract
A modified procedure for the determination of urinary 17-hydroxycorticosteroids (di-hydroxy-acetonyl-corticoids) is described. The use of ethyl ether in a single extraction step and the stabilization of the phenylhydrazine-sulfuric acid reagent with sodium chloride are the unique features of the method. Studies of chromogenicities of steroids, recovery, pH effect on extraction, and salt effect on the stability of Porter-Silber reagent in the presence and absence of light during storage are reported; chemical aspects of chromogenic development of various steroids are discussed, clinical ranges compared, and interpretations evaluated.
Urinary Pregnanediol and Pregnanetriol: Spectrophotometric Determination Following Aluminum Oxide Column Chromatography
Authors: Klein Daniel , Chernaik Joseph M 
Published: January 2020

Abstract
A modification of the procedure for urinary pregnanediol and pregnanetriol is described employing enzymatic hydrolysis, solvent extraction, separation on aluminum oxide by partition gradient elution, and determination by use of the sulfuric acid color reaction. A procedure has been devised for overcoming chromogenic interference by impurities, especially with the pregnanediol determination, based on utilization of the absorption curve characteristics of these two steroidal chromogens in H2S04. One essential step is the incorporation of the standards into one of a pair of urine extracts; a second is the collection of a small number of eluates for both the pregnanediol and pregnanetriol fractions. By the wavelength of peak absorption obtained in H2S04 for each eluate residue, the proper eluates are then selected for the determination of each of the two steroids. The method requires simple equipment readily available in clinical chemistry laboratories, and gives results that compare very favorably with those obtained with other procedures.
The Precision, Accuracy, and Inherent Errors of Automatic Continuous Flow Methods
Authors: Thiers R E , Oglesby K M 
Published: January 2020

Abstract
An automatic continuous-flow system was evaluated under routine daily use for six constituents, sodium, potassium, chloride, carbon dioxide, urea, and glucose. Two parameters have been quantified, interaction between samples and instrumental drift. Results also were influenced by the available amount of sample. Application of correction technics is shown to improve the accuracy of the automatic-analysis system.
Analyses on Heat-coagulated Blood and Serum
Authors: London Morris , Marymont Jesse H 
Published: January 2020

Abstract
A method for the quantitative separation of serum urate from the proteins present, that does not employ chemical precipitation, is presented. The separation is accomplished by heat coagulation of serum and the subsequent aqueous extraction of the purine from the intact coagulum. Serum is placed at the bottom of a container of sufficient size to permit the formation of a thin layer and then coagulated in a boiling-water bath. The resultant coagulum is firm, adherent to the container, and not easily disrupted. Water is then added to cover the coagulum and the urate extracted. The urate present in the extract is determined using a phosphotungstate reduction method.
Enzyme Activities of Human Inferior Vena Cava
Authors: Kirk John Esben 
Published: January 2020

Abstract
A comparison was made of activities of 15 different enzymes in normal tissue samples of the inferior vena cava and aorta derived from the same subjects. Statistically significant differences between venous and arterial specimens were observed for 10 of these enzymes. Comparative studies on the intermediary metabolism of the vascular walls may disclose some of the factors responsible for the low susceptibility of human veins and the high susceptibility of human arteries to sclerotic changes.
An Automated Method for the Determination of Serum Bilirubin
Authors: Golub Murray 
Published: January 2020

Abstract
The bilirubin method of Rand and DiPasqua (3), which utilizes a stabilized diazonium salt solution of 2,4 dichloraniline, has been adapted to automatic chemical analysis. Both total bilirubin and "1-min. reacting" bilirubin can be assayed with good accuracy and precision. Data are presented to show excellent agreement with the manually performed procedure and the procedure of Malloy and Evelyn (1), which was used as the reference method.
Modern Methods for Determining Cerebrospinal Fluid Protein
Authors: Watson Derek 
Published: January 2020

Abstract
A simple and rapid micro method for the determination of albumin and total protein in cerebrospinal and other body fluids is presented. It is based on the UV spectrophotometric measurements of neutral and acid-alcohol-treated spinal fluid and is shown to be accurate and reproducible. Using spectrophotometry at 220 mµ and two other recently improved technics, 84 specimens of spinal fluid from infants were analyzed for total protein. The results obtained showed good agreement over the range 30-200 mg./100 ml.
Seroflocculating Steroids
Authors: Chang Frederic C 
Published: January 2020

Abstract
The basis and plan of research on a group of steroids having seroflocculating activity, with the aim of developing a test for use in diagnosis of cancer,† are reviewed. Compounds classified into activity groups in earlier reports have been summarized, tentative activity-structure relationships are indicated, and a relative group-activity series has been derived from the screening. A discussion of the research is given.
Automated Determination of Serum Glutamic Oxalacetic and Glutamic Pyruvic Transaminase
Authors: Schaffert Roscoe R , Kingsley George R , Getchell Gloria 
Published: January 2020

Abstract
The determination of serum glutamic oxalacetic and glutamic pyruvic transaminase has been simplified by the use of automated analysis. The flow diagrams, concentration of reagents, and calculation of the color unit in terms of the Karmen unit are shown for 2,4-dinitrophenylhydrazine and 6-benzamido-4-methoxy-m-toluidine diazonium chloride as the reacting dyes. Advantages of both methods are compared and discussed.
A New Method for the Determination of Ascorbic Acid in Urine
Authors: Kum-Tatt Lee , Leong P C 
Published: January 2020

Abstract
A simple method for the determination of ascorbic acid in urine was developed. The method is based on the quantitative reduction of mercuric chloride to mercurous chloride at pH 3.5-5.0. The insoluble mercurous chloride was separated by centrifugation, dissolved in excess standard iodine-potassium iodide solution and back-titrated with standard sodium thiosulphate. The method has precision, and as little as 1.0 mg. of ascorbic acid per 100 ml. of urine can be determined with an accuracy of ± 3%. Common substances found in urine do not interfere.
Screening Test for Fast Isoniazid Inactivators
Authors: Eidus L , Hamilton E J 
Published: January 2020

Abstract
A screening test is described for assaying fast inactivators of isoniazid (INH) in serum. Trichloracetic acid filtrates are reacted with a trans-cinnamaldehyde reagent to form a colored hydrazone derivative of INH. The metabolic degradation of the drug is discussed as well as interferences. The color is read at 352-354 mµ.
Coproporphyrin Analyses on Random Urine Samples
Authors: Rogers Charles J 
Published: January 2020

Abstract
The fluorometric procedure of determining coproporphyrin has been adapted to determine coproporphyrin on random urine specimens. This adaptation depends on determining both coproporphyrin and creatinine. A mathematical relationship is established for the amount of coproporphyrin excreted when 1200 mg. of creatinine is excreted.
An important advantage of the random procedure is the elimination of the waiting period of 24 hr. for the urine collection. This is particularly important in porphyric urines since much of the porphyrin is reduced to forms that are sensitive to light, with the result that pathologic levels of coproporphyrin may thus be overlooked.
Differential Spectrophotometric Determination of Calcium
Authors: Radin Nathan , Gramza Adalbert L 
Published: January 2020

Abstract
The appearance of kits for the determination of micro amounts of calcium stimulated our interest in the use of Eriochrome Blue SE for this analysis. A study of spectrophotometric curves indicates that, at pH values above 13.7, calcium will complex and cause a change of dye absorbance while magnesium does not complex with the dye. A differential spectrophotometric technic is described in this paper in which the spectrophotometer is set at zero absorbance with a dye-calcium standard solution or a dye-calcium sample solution as reference and the absorbance of the dye solution then measured. For a set of standards the absorbance-calcium relationship is linear. With the Beckman spectrophotometer, Model DU, it has been found that 1 part of serum to 100 parts of alkaline dye solution (100 λ of serum to 10 ml. alkaline dye solution) can be used. The technic shows greater sensitivity and accuracy than do previous methods using Eriochrome Blue SE.
Lactic Dehydrogenase
Authors: Weinberg Myron S , Adler Daniel H 
Published: January 2020

Abstract
Determination of lactic dehydrogenase (LDH) activity has been shown to have diagnostic value in pathologic states involving tissue necrosis and neoplasia. Necrotizing tissues release this enzyme, which catalyzes the reduction of pyruvate to lactate or the reverse, in an active state. As a result of this release, the enzyme appears in body fluids, notably the blood. Increase of this activity over normal indicates necrosis.
The present paper compares the results of the Wroblewski and LaDue and the Wacker et al., methods for measuring LDH activity.
Results of the two methods were found to be not comparable. No calculation can be found to relate the results of the two analytical methods. Only 18 of 30 samples gave abnormally high results by both methods. Changes between serial samples drawn on the same patient are not always in the same direction when measured by both methods. Lack of mathematical correlation between the kinetics of the pyruvate-to-lactate reaction and the lactate-to-pyruvate reaction is assumed to explain this.
Determination of Uric Acid
Authors: Crowley Leonard V 
Published: January 2020

Abstract
An automated method is described for the determination of uric acid by a carbonate method. Since uric acid is separated from proteins by dialysis, the loss of uric acid due to protein precipitation in manual methods is avoided. There is no appreciable interference from salicylates, high levels of blood sugar, or ascorbic acid. The method shows an acceptable correlation with the uricase method.
Determination of the Iron-binding Capacity of Blood Serum
Authors: Nadeau Guy , Fortin Benoit 
Published: January 2020

Abstract
A simple experiment was performed to ascertain whether procedures for estimating the iron-binding capacity (IBC) of blood serum are quantitative. This was accomplished by adding β-globulin (obtained by fractionation of human plasma) to various serum specimens. The β-globulin solutions were first assayed for their IBC. Their addition to serum in these recovery experiments provided data for evaluation of methodology.
Semimicro Flame Photometry of Serum Sodium and Potassium
Authors: Dryer R L 
Published: January 2020

Abstract
A method for the determination of serum sodium and potassium involving only a single serum dilution is described.
Samples of 0.1 ml. of serum suffice for both determinations, but larger samples may also be used.
By careful control of the lithium concentration and the dilution factor the mean relative photometric error may be held to no more than 1 per cent under normal circumstances of operation.
Blood pH Measurement with the Glass Electrode
Authors: Natelson Samuel , Tietz Norbert 
Published: January 2020

Abstract
A study has been described to explain the tendency of fingertip blood from normal individuals to drift to alkaline pH more rapidly than the blood of venous serum at 37°. This occurs even under oil and without loss of CO2. Evidence is offered to indicate that this phenomenon is due to the release of carbonic anhydrase in greater concentrations into the serum when the finger is punctured than when venipuncture is performed. An explanation is offered for the fact that serum from patients in acidemia with low CO2. content will not drift at 37°.
It is suggested that blood pH determinations be made by collecting the specimen under oil, cooling rapidly to room temperature, and performing the determination under oil on the separated serum.
Serum Protein Analysis by Electrophoresis and by the Wolfson-Cohn Chemical Method
Authors: Eriksen Nils , Ellerbrook Lester D , Lippincott Stuart W 
Published: January 2020

Abstract
One hundred serum specimens from healthy and diseased adults were analyzed for the major protein constituents by free electrophoresis and by the Wolfson-Cohn chemical method. Albumin values obtained by the two methods were well correlated and were also in good average numerical agreement. The γ-globulin values were well correlated, but were not in quite such good numerical agreement, on a percentage basis, as were the albumin values. The α-globulin values were poorly correlated, as were also the β-globulin values.
Electrophoretic examination of some of the chemical fractions indicated that part of the discrepancy between the two methods was caused by faulty chemical fractionation, particularly with respect to the globulin fractions.
Determination of total solids retained by a dialysis membrane (TS) in 22 serum specimens confirmed the proportionality between TS and the electrophoretic-pattern area, and emphasized a source of error of undetermined magnitude in the calculation of electrophoretic results from simple protein totals.
Semimicro Method for the Determination of Salicylate Levels in Blood
Authors: Routh J I , Paul W D , Arredondo Emilio , Dryer R L 
Published: January 2020

Abstract
A micro method for salicylates capable of determining levels of 0 to 50 µg./ml. on fingertip blood specimens has been developed. The method is characterized by low plasma or whole blood blanks, the ability to measure very low salicylate levels, and sufficient range to compare favorably with the macro method of Brodie et at. at higher levels.
Determination of Glucose with a Research Model Aminco "Rotochem" by the Hexokinase Reaction
Authors: Hasson William , Penton James R , Widdowson Graham M 
Published: January 2020

Abstract
A method involving the hexokinase reaction is described for determining glucose in serum with a Research Model Aminco "Rotochem." The need to measure a separate sample blank is eliminated by using the computational capabilities of a small computer interfaced with the Rotochem. In this modification of the method of Tiffany et al., a cubic curve is fitted to the initial portion of the reaction path. Sample blanks are calculated by extrapolation back to zero time. The procedure is precise and results correlate well with those for an accepted automated procedure in which the same reaction is used.
Separation of Tissue and Serum Creatine Kinase Isoenzymes by Ion-Exchange Column Chromatography
Authors: Mercer Donald W 
Published: January 2020

Abstract
I describe a simple, rapid anion-exchange column chromatographic technique for separating the creatine kinase (CK) isoenzymes in human serum and tissue. Extracts of CK-rich tissues (skeletal muscle, cardiac muscle, and brain) were used to determine optimum conditions for separating CK isoenzymes MM, MB, and BB. Samples, layered on mini-columns (0.5 x 6.0 cm) of DEAE-Sephadex A-50, were eluted stepwise with Tris-buffered sodium chloride (100, 200, and 300 mmol/Iiter). Column effluents were assayed by the Rosalki CK method. Distribution of total activity among the eluted fractions was tissue-specific and reproducible. Evaluation of sera from 71 patients with myocardial infarction and other diseases associated with elevated CK activity revealed isoenzyme patterns that resembled those of either cardiac muscle or skeletal muscle. Cardiac pattern (presence of MB isoenzyme) and clinical documentation of myocardial infarction were 100% correlated in the 35 patients so studied.
CEA-Like Material in Fluid from Benign Cysts of the Breast
Authors: Fleisher Martin , Oettgen Herbert F , Breed Charles N , Robbins Guy F , Pinsky Carl M , Schwartz Morton K 
Published: January 2020

Abstract
A preliminary survey of carcinoembryonic antigen (CEA) concentrations in 23 breast-cyst fluids (BCF) and blood plasma has revealed markedly increased concentrations of CEA-like material in BCF as compared to its concentrations in plasma. Chromatography on Sephadex G-200 indicated the immunoreactive CEA component extracted from BCF corresponds to a glycoprotein with a molecular weight of at least 200 000.
Principles of Competitive Binding Assays (Saturation Analyses). II. Sequential Saturation
Authors: Zettner Alfred , Duly Peggy E 
Published: January 2020

Abstract
The principles of sequential saturation as a form of competitive binding assays are discussed in detail and differentiated from those of equilibrium techniques. The rationale of its applicability in practice and its potential to increase sensitivity under certain assay conditions are demonstrated with three binding systems involving digoxin, insulin, and folates. The advantages and disadvantages of the sequential saturation technique are outlined.
Evaluation of an Improved Pneumatic-Tube System Suitable for Transportation of Blood Specimens
Authors: Pragay D A , Edwards L , Toppin M , Palmer R R , Chilcote M E 
Published: January 2020

Abstract
An improved version of a pneumatic-tube system built by Amsco, Inc. (Erie, Pa.) and its subsidiary ATC (San Rafael, Calif.) for blood-sample transportation incorporated two innovations: The sample carrier travels at a lower speed than in the previous conventional systems, and it is decelerated gradually on arrival. This tube system was pilot tested for efficiency by running blood-filled Vacutainer tubes through the 63.6-rn (210-feet) tube 10 times, a total running distance of 636 m. Serum lactate dehydrogenase and acid phosphatase activities, and potassium, all sensitive chemical indicators of erythrocyte membrane damage, were measured in blood specimens in partially or totally filled Vacutainer tubes and the results compared with those obtained from controls. No alterations were found in serum test results after 10 or 20 repetitive cycles in the totally filled tubes, but significant changes did occur in partially filled tubes after 20 cycles. If the limitations are observed, this system appears to be suitable for blood-specimen transportation.
Identification of Hemoglobins and Hemoglobinopathies by Electrophoresis on Cellulose Acetate Plates Impregnated with Citrate Agar
Authors: Schneider Rose G , Hosty Thomas S , Tomlin Gary , Atkins Ruby 
Published: January 2020

Abstract
We describe a method of electrophoresis of hemoglobin on cellulose acetate plates impregnated with citrate agar, which remain stable for many months and are used to confirm rapidly the presence of hemoglobins S and C and the hemoglobinopathies associated with them. The method also provides excellent separations of hemoglobins F and A and reliable identification of genetically determined hemoglobin abnormalities in the newborn.
Measurement of Antibodies to Insulin in Serum
Authors: Dixon K 
Published: January 2020

Abstract
I describe a method for measuring insulin antibodies in insulin-treated subjects. The antibodies are characterized by maximum binding capacity and affinity constant. Endogenous and therapeutic insulin interferes in insulin antibody assay, and it is removed by dextran—charcoal treatment at pH 3.5. Endogenous total and free insulin may be measured by a simple extension of the method.
Assessment of the Reference Method for Determination of Total Calcium in Serum
Authors: Pickup John F , Jackson Malcolm J , Price E Margaret , Brown Stanley S 
Published: January 2020

Abstract
The Reference Method [Clin. Chem. 19, 1208 (1973)] for determination of calcium in serum has been critically assessed, both to evaluate its performance in one laboratory and to identify ambiguities and errors in the published texts. Within-run and between-run precision and bias have been estimated, and a revised protocol is presented.
Use of Tris Buffers for Quality Control of Blood pH
Authors: Ladenson Jack H , Smith Carl H , Dietzler David N , Davis J E 
Published: January 2020

Abstract
Tris(hydroxymethyl)aminomethane buffers have been established as sensitive and convenient indicators of the reliability of blood pH analysis. These buffers were compatible for routine use with blood-pH equipment from major manufacturers, except for two instruments. A seven-month study demonstrated the necessity of a routine quality-control program, as well as the need for systematic cleaning and maintenance of pH equipment. Tris(hydroxymethyl)aminomethane buffers were found not to be suitable as primary standards because we could not obtain the stated values with commercial pH equipment that had been standardized with phosphate buffers from the National Bureau of Standards. The relative standard deviation for measurement of hydrogen ion activity, 4.1% , indicates a need for improvement in the design and operation of equipment for the measurement of blood pH.
The Hoesch Test: Bedside Screening for Urinary Porphobilinogen in Patients with Suspected Porphyria
Authors: Lamon Joel , With Torben K , Redeker Allan G 
Published: January 2020

Abstract
A little-known procedure for porphobilinogen screening, the Hoesch test, was examined for sensitivity, specificity, and utility as compared to the Watson-Schwartz test. The data demonstrate that its sensitivity is similar to that of the Watson-Schwartz test. The Hoesch test, however, is without false-positive reactions secondary to urobilinogen, and its simplicity makes it easier to use and more easily interpretable. We conclude that the Hoesch test should replace the Watson-Schwartz test for urine porphobilinogen screening in suspected cases of acute intermittent and variegate porphyria.
2-Amino-2-methyl-1-propanol as the Alkalizing Agent in an Improved Continuous-Flow Cresolphthalein Complexone Procedure for Calcium in Serum
Authors: Moorehead Wells R , Biggs Homer G 
Published: January 2020

Abstract
We describe an improved cresolphthalein complexone procedure for calcium in which diethylamine is replaced by a nontoxic amino alcohol. Advantages of the procedure are increased sensitivity, excellent baseline stability, a more optimum reaction environment (pH 10.0) that eliminates blanking problems, and freedom from interference by magnesium. Values obtained by this method are not significantly different (P &lt; 0.05) from those obtained by atomic absorption spectrophotometry.
Rapid Gas-Chromatographic Determination of Amphetamine and Methamphetamine in Urine
Authors: Jain Naresh C , Sneath Thomas C , Budd Robert D 
Published: January 2020

Abstract
A simple, rapid procedure is described for measuring amphetamine and methamphetamine in urine by gas chromatography, with use of a flame ionization detector. This method is sensitive to subtherapeutic concentrations (0.1 µg/ml or less), and is especially useful in clinical situations where an accurate and quantitative result is needed in less than 30 min. With the method, amphetamine and methamphetamine can be determined as the free bases on a 10% Apiezon L-10% KOH column and as their trifluoroacetamide derivatives on a 3% OV-17 column. This dual analysis eliminates false positives and any interfering substances that may be present in the urine, and is thus a specific method for the two drugs.