bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Total Iodine in Urine, Stool, Diets, and Tissue
Authors: Benotti Joseph , Benotti Norbert , Pino Samuel , Gardyna Henry 
Published: January 2020

Abstract
A method is presented for determination of total iodine in biologic material. The procedure requires a minimum number of reagents, eliminating the possibility of reagent iodine contamination. The actual cost of equipment for this method is less than for others, and the method offers good replication and excellent recovery of added iodine.
A Micro Method for Serum Cholinesterase
Authors: Garry Phil J , Routh Joseph I 
Published: January 2020

Abstract
A simple colorimetric method for determining serum or plasma cholinesterase has been described. The cholinesterase acts on acetylthiocholine to release thiocholine, which reacts with 5:5-dithiobis-(2-nitrobenzoic acid) to produce a yellow color. The activity is measured after incubation for 3 min. at 37° the reaction is stopped by the excess addition of quinidine sulfate. The difference in absorbance between the blank and test sample is then measured at 412 mµ. Duplicate determinations can be run on 0.1 ml. of serum or plasma, and the method is well suited to laboratories using routine procedures.
Serum Bile Acids in Patients with Liver Disease
Authors: Levin Samuel J , Schwartz Morton K 
Published: January 2020

Abstract
By means of a sensitive fluorometric technic, serum bile acids were determined in patients with various liver diseases. Correlations were shown between the bile acid values and those of transaminase and alkaline phosphatase in cases of liver metastases, and bile acid and transaminase values in cases of viral hepatitis. For most clinical purposes, however, the determination does not yield information which cannot be obtained more readily using currently accepted methods.
Determination of Calcium in Urine by the Chloranilate Method
Authors: Webster William W , Kern William H 
Published: January 2020

Abstract
Evidence is presented that the colorimetric chloranilate calcium method can be accurately applied to urine provided that elimination of interfering substances, which include magnesium, is performed prior to the determination. Isolation of calcium as the oxalate, followed by perchloric acid digestion, has been shown to be an acceptable method whereby urinary calcium can be put in a suitable state for analysis. Allowing the urine to stand for 1 hr. at pH 2 prior to the oxalate precipitation has been shown to be a simple means of eliminating the sampling error due to calcium precipitates.
An Automated p-Nitrophenylphosphate Serum Alkaline Phosphatase Procedure for the AutoAnalyzer
Authors: Morgenstern Stanley , Kessler Gerald , Auerbach Joseph , Flor Richard V , Klein Bernard 
Published: January 2020

Abstract
A new and simplified procedure for the automated determination of serum alkaline phosphatase uses the AutoAnalyzer. The substrate p-nitrophenylphosphate in 2-amino-2-methyl-1-propanol offers the prime advantage of providing directly its own chromogen, p-nitrophenol, following enzyme action. The procedure also permits use of small sample volumes, provides linear reaction rates, and has a simple manifold design. Correlations are presented between the manual procedure and the automated system.
Analysis of Urinary 17-Ketosteroids by Gas-Liquid Chromatography
Authors: Ruchelman Maryon W , Cole V William 
Published: January 2020

Abstract
A method is presented for the resolution of urinary 17-ketosteroids (17-KS) by gas liquid chromatography (GLC) for clinical application. Hot acid hydrolysis with sulfuric acid is followed by ether extraction, 1 N NaOH wash, and NaOH pellets to serve for both purifying and drying agent. All steps take place in the same reaction tube and are adapted for mechanical shaking. The method allows one analyst to prepare 6-8 urine extracts and trimethylsilyl ether (TMS) derivatives in 1 working day, with GLC the next morning. A quantitative fractionation is routine within 24 hr.
The Interference of Chlorpromazine Metabolites in the Analysis of Urinary Methoxy-Catecholamines
Authors: Blumberg Arnold G , Heaton Audre M , Vassiliades John 
Published: January 2020

Abstract
The analysis of urinary methoxy-catecholamines by the method of Pisano (1) could not be applied to the urine of patients who were receiving chlorpromazine. Chlor-promazine and the chlorpromazine metabolites, 7-hydroxychlorpromazine and chlor-promazine sulfoxide, were shown to interfere with the column chromatographic separation and spectrophotometric analysis of the methoxy-catecholamines.
A Continuous Spectrophotometric Method for Measuring the Activity of Serum Alkaline Phosphatase
Authors: Bowers George N , McComb Robert B 
Published: January 2020

Abstract
A continuous spectrophotometric method for measuring serum alkaline phosphatase activity is described. The effects of temperature, pH, substrate concentration, type and molarity of the buffer, sample size, cofactors, and inhibitors on the enzymatic hydrolysis of p-nitrophenyl phosphate were studied. The optimal conditions for assay of serum alkaline phosphatase at 30° were found to be 0.75 M 2-amino-2-methyl-1-propanol buffer, pH30° 10.15, 4 mmole substrate, and 100 µl. or less sample size. Studies of the factors affecting analytical precision-i.e., control of reaction temperature, of reagent manufacture, and of standardization-are discussed. The precision of this method was 2.3% (relative standard deviation) on 10 within day replicates and 5.0% on day-to-day replicates spread over a 5-week period. The range of activity for 258 apparently healthy adult blood donors was 6-110 mU./ml. (International milliunits per milliliter), with a mean of 49 and a standard deviation of 14.
Automated Determination of Serum Glutamic Oxaloacetic Transaminase
Authors: Morgenstern Stanley , Oklander Morris , Auerbach Joseph , Kaufman James , Klein Bernard 
Published: January 2020

Abstract
A simplified and precise automated method is described for the colorimetric determination of serum glutamic oxaloacetic transaminase. The enzymically generated oxaloacetic acid is dialyzed, coupled with Fast Ponceau L, a diazonium salt, to form a colored solution whose absorbance is measured at 455 mµ. Dialysis eliminates the need for a serum control determination, thereby halving the analysis time, which is usually 1 hr. per 40 specimens. Comparison of values obtained using this procedure with and without dialysis shows excellent agreement. Comparison with the spectrophotometric procedure shows good correlation. The results of sample interaction experiments are also presented.
Use of the Activated Partial Thromboplastin Time in the Control of Heparin Administration
Authors: Lenahan Jane G , Frye Sheldon , Phillips George E 
Published: January 2020

Abstract
The activated partial thromboplastin time (APTT) was compared to the whole blood clotting time (WBCT) as a control of heparin administration. The APTT was shown to be a sensitive system for the control of heparin therapy, with the added advantage that the blood can be drawn and taken to the laboratory for assay. The effective therapeutic range in man remains to be established.
A Rapid Electrophoretic Method for the Determination of the Isoenzymes of Serum Lactate Dehydrogenase
Authors: Opher Albert W , Collier Charles S , Miller Joseph M 
Published: January 2020

Abstract
A convenient electrophoretic procedure for the separation and quantitation of lactate dehydrogenase (LDH) isoenzymes is described. The system uses polyacetate Sepraphore III strips.* The areas of activity are shown by incubation with an LDH substrate combined with tetra-nitro-blue-tetrazolium. The reduction of the latter to the purple formazan is quantitatively related to the enzyme activity. Quantitative determination of the individual colored areas is performed by densitometry.
Thin-Layer Starch-Gel Electrophoresis
Authors: Lewis Lena A 
Published: January 2020

Abstract
A modification of the starch-gel electrophoresis technic of Smithies is presented,which enables quantitation of the resolved fractions to be carried out with little equipment other than that used for paper electrophoretic fractionation of proteins.A sheet of plastic (Stabilene film) wrapped around a kymograph type drum is evenly coated with starch-gel. The sheet is suspended in an "open strip" Durrum type cell and electrophoresis carried out. After staining with suitable stain to demonstrate proteins, lipids, or other components, the patterns are scanned in a photoelectric densitometer. Results obtained with this procedure show good reproducibility when fractionating solutions of hemoglobin and serum proteins.
Modifications of the Automated Procedure for Blood Phenylalanine
Authors: Hill John B , Summer George K , Hill Hoyle D 
Published: January 2020

Abstract
The automated procedure for blood phenylalanine was modified by the use of glycyl-l-Jeucine and a Corning glass filter No. 7-51. In addition, data were obtained showing that dried blood spots were stable for 11 weeks and samples analyzed at rates of 30 and 60 per hour gave the same results.
X-Ray Spectroscopy in Biology and Medicine
Authors: Mathies James C , Lund Paul K 
Published: January 2020

Abstract
An X-ray emission spectrographic procedure for the quantitative analysis of calcium, sulfur, and phosphorus in urinary calculi has been devised. Duplicate quantitative analyses are possible if 150 µg. of specimen is available. The calcium-, phosphorus-, and sulfur-containing compounds in the sample are quantitatively dissolved in 0.05 M disodium ethylenediaminetetraäcetate prepared in N ammonium hydroxide. An aliquot of this solution, representing 50 µg. of sample, is dried as a thin film on an aluminum foil planchet and quantitated for the indicated elements using the X-ray spectrograph. Preparation of uniform dry films is ensured by adding methylcellulose to the solution of calculus salts. The precision of the method permits estimation of the calcium, sulfur, and phosphorus in each specimen to the nearest whole per cent. Analytic data on 245 specimens of urinary calculi from humans are summarized.
A Rapid Semimicro Method for Determining Protein-Bound Iodine
Authors: Yee Hugh Y , Katz Edwin S , Jenest Edward S 
Published: January 2020

Abstract
An improved 4 hr. semimicro method for the determination of PBI that has an S.D. of 0.30 is presented. The advantageous features include the use of a 0.1-ml. sample size, the removal of inorganic iodide by an anion resin obviating the protein-precipitation step, and the utilization of an ashing time of 35 min. The suitability of this method for the small laboratory becomes apparent in terms of the time saved as well as in the expense of equipment and reagents.
Automated Determination of Serum Glutamic Oxaloacetic Transaminase
Authors: Morgenstern Stanley , Kaufman James H , Klein Bernard 
Published: January 2020

Abstract
A new and sensitive procedure is described for the automated determination of serum glutamic oxaloacetic transaminase using the Robot Chemist. Enzymically generated oxaloacetic acid is directly coupled with the diazonium salt, fast ponceau L, to form a colored solution whose absorbance is measured at 455 mµ. Correlations are presented between this method and the AutoAnalyzer procedure using the same reagent.
Determination of Serum Calcium by Automated Atomic Absorption Spectroscopy
Authors: Klein Bernard , Kaufman James H , Morgenstern Stanley 
Published: January 2020

Abstract
A procedure is presented for the automated determination of serum calcium by atomic absorption spectrophotometry. The serum sample, diluted with acidified lanthanum dichloride, is dialyzed against 0.1 N hydrochloric acid and a portion of the recipient solution is pumped into the atomizer-burner of the spectrophotometer. Data are presented on the precision and reproducibility of the flow system. Addition of calcium to serum shows a mean recovery of 99%. A comparison of the results of analyses on random specimens by permanganate titration and the automated procedure shows good agreement.
Stability of Plasma Enzymes During Storage
Authors: Juul Per 
Published: January 2020

Abstract
For measurement of plasma enzyme stability, 18 specimens of whole blood, plasma, and serum from normal subjects were stored at different temperatures. Eight enzymes were assayed after different times of storage: acetylcholinesterase, pseudocholinesterase, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, lactic dehydrogenase, acid and alkaline phosphatases, and amylase. At -200° all enzymes except lactic dehydrogenase were stable for 8 days, while at 38° all except amylase were unstable. At 4° the stability of the enzymes differed in whole blood, plasma, and serum, with a tendency toward greater stability than is usually reported.
Calcium Determinations in Kinetic Studies
Authors: Harrison Joan , Hitchman A J W , Finlay J M 
Published: January 2020

Abstract
Published reports of a fraction of blood calcium that does not equilibrate with a tracer has created a controversy that challenges the validity of much calcium kinetic data. To resolve this controversy, calcium specific-activity measurements were made on blood and urine samples in vitro and in vivo. The experiments were designed to provide maximal sensitivity for demonstrating non exchangeable calcium. A new and accurate method for urine calcium determinations was used. The results demonstrated complete equilibration between tracer and stable blood calcium. We suggest that published evidence of non exchangeable calcium in blood and urine is erroneous due to inaccurate urine calcium determinations.
Application of Thin-layer Chromatography to the Quantitation of Plasma Neutral Lipids and Free Fatty Acids
Authors: Louis-Ferdinand Robert T , Therriault Donald G , Blatt William F , Mager Milton , Metheson Edward J 
Published: January 2020

Abstract
Neutral lipids and free fatty acids were extracted from plasma and separated on thin-layer chromatoplates coated with silica gel G. The plates were charred by heating after spraying with dichromate-sulfuric acid, and then evaluated densitometrically. Plasma analyses obtained by this procedure were compared with parallel determinations performed by established chemical technics.
Simultaneous Determination of Pregnanediol and Pregnanolone in Urinary Extracts by Gas Chromatography
Authors: Guarnieri M , Barry R D 
Published: January 2020

Abstract
A method for the simultaneous determination of pregnanediol and pregnanolone in urinary extracts by gas chromatography is described. The method involves prior enzymatic hydrolysis of the steroid conjugates, chloroform extraction, and quantitation by means of gas chromatography.
The Stability of a Reconstituted Serum for the Assay of Fifteen Chemical Constituents
Authors: Hanok Albert , Kuo Jeremiah 
Published: January 2020

Abstract
A study was made of serums stored at refrigerator (10°) and freezer (-15°) temperatures in relation to the subsequent effect on the following assays: sodium, potassium, chloride, carbon dioxide, protein, albumin, calcium, alkaline phosphatase, glutamic oxalacetic transaminase, bilirubin, urea nitrogen, glucose, uric acid, creatinine, and phosphorus. Data showing the period for which a reconstituted serum may be stored under these conditions are presented.
A Study of 2,4,6-Trinitrobenzenesulfonic Acid for Automated Amino Acid Chromatography
Authors: Brown Harold H 
Published: January 2020

Abstract
The reaction of 2,4,6-trinitrobenzenesulfonic acid (TNBS) with amino acids was investigated by a static system to develop optimum conditions for application to automated amino acid chromatography. TNBS was found to be a very simple and sensitive reagent, easier to use than ninhydrin. The reaction occurs quite rapidly at room temperature, eliminating the requirement of a heating bath. The major disadvantage is a much lower sensitivity to the imino acid proline than to the amino acids.
Determination of Body Water Content Using Trace Levels of Deuterium Oxide and Infrared Spectrophotometry
Authors: Stansell Marion J , Mojica Luis 
Published: January 2020

Abstract
A procedure is described for the determination of total body water content of human subjects using 11- to 12-gm. doses of deuterium oxide (D2O), vacuum sublimation of serum samples, and quantitation of the deuterium by infrared spectrophotometry at 2510 cm.-1. The coefficient of variation based on day-to-day procedure reproducibility is less than 2%. D2O added to serum is completely recovered in the sublimation and assay operations. The D2O dilution procedure compares favorably with the tritium dilution technic, with values obtained on 45 out of 46 individuals falling within the ±3 combined S.D. limits for the two methods. The significance of the total body water data is discussed.
The Effect of Formalin and the Duration of Acid Hydrolysis on Free and Conjugated Urinary 17-Ketosteroids
Authors: Goldzieher Joseph W , de la Pena Armando 
Published: January 2020

Abstract
The recovery of five free ketosteroids, three glucuronides, and six sulfates, added to water or urine and subjected to acid hydrolysis for various lengths of time, was investigated. Dehydroepiandrosterone (DHEA) in all its forms was most susceptible to destruction. The behavior of glucuronides and sulfates differed, and no single set of conditions provided equal recovery for all conjugates. A compromise time of 30 min. of hydrolysis appeared to be optimal. The addition of formalin diminished nonspecific chromogens in a variable manner, but also accelerated destruction of DHEA and decreased the recovery of ketosteroid sulfates.
Creatine Phosphokinase Activity in Myocardial Infarction, Heart Failure, and Following Various Diagnostic and Therapeutic Procedures
Authors: Crowley Leonard V 
Published: January 2020

Abstract
The creatine phosphokinase(CPK) test based on the method of Okinaka et al. (1) was compared with the glutamic oxalacetic transaminase (GOT) test of Reitman and Frankel (2) in patients with myocardial infarction, cardiac failure, and following various diagnostic and therapeutic procedures. The CPK method used was somewhat less discriminatory than the GOT method in detecting myocardial infarction. The CPK test possessed greater specificity, since it was not elevated in congestive cardiac failure, while the GOT test was elevated in 25% of the patients with heart failure. Therefore, the CPK test offered a real advantage when evaluating suspected infarction in the presence of cardiac failure. CPK activity may be elevated when the GOT test is normal, indicating the advantage of performing more than one enzyme procedure in suspected myocardial infarction.
Both GOT and CPK were elevated in many patients following surgical operation and cardiac catheterization. No CPK elevations were encountered after electroconvulsive therapy, and CPK was only occasionally elevated following coronary arteriography.
Rapid Detection of Organic Phosphorus Poisons
Authors: Fischl J , Pinto N , Gordon C 
Published: January 2020

Abstract
Strips of filter paper are impregnated with a buffered acetylcholine substrate solution, containing phenol red as an indicator, and 1,2-propyleneglycol serving as an inhibitor of bacterial decomposition and as a wetting agent. The test is suitable for the detection of the poison in vivo, as well as in suspected materials such as food, clothing, water, soil, and air samples. The test is based on the inhibition of acetylcholinesterase by the organophosphoric group of the substances. In positive tests the indicator paper turns pink-to-violet and in negative tests it turns a yellow color.
A New Time-Saving Method for Determining Nitrogen in Biologic Material
Authors: Dambacher M , Gubler Alice , Haas H G 
Published: January 2020

Abstract
A new method for the determination of nitrogen in biologic material is described. It is based on an improved ashing procedure and the Berthelot reaction in which nitrogen is converted to indophenol. The concentration of this substance is determined photometrically. The proposed method yields the same results as the Kjeldahl procedure; however, it offers a higher degree of sensitivity combined with the same degree of accuracy. In addition, the determination requires only 4 hr., in comparison to 24 hr. for the Kjeldahl method.
Comparison Between Thiocholinesters and o-Nitrophenylbutyrate as Substrates in the Assay of Serum Cholinesterase
Authors: Szasz Gabor 
Published: January 2020

Abstract
The technical and clinical usefulness of three substrates for serum cholinesterase were compared. The diagnostic value of acetylthiocholine was equal to that of butyrylthiocholine and superior to that of o-nitrophenylbutyrate. Technically, butyrylthiocholine is superior to the other two substrates chiefly because of its greater affinity for serum cholinesterase. A kinetic method using o-nitrophenylbutyrate is described that is capable of carrying out 60 tests per hour with good results.
Semimicro Method for Determination of Serum Uric Acid Using EDTA—Hydrazine
Authors: Patel C P 
Published: January 2020

Abstract
A semimicro method is described for the determination of uric acid by manual and automated procedures. Serum uric acid reduces phosphotungstic acid in an alkaline medium of EDTA sodium tungstate and hydrazine sulfate, the latter being used as a color intensifier. The use of sodium tungstate eliminates the development of interfering turbidity encountered with other alkalizing reagents. This method requires only 0.2 ml. of serum. The presence of ascorbic acid, sodium salicylate, cysteine, and/or glucose does not interfere. A linear relationship is obtained upon comparing this method with the sodium carbonate and the differential ultraviolet spectrophotometric methods.
Practical Acetate Membrane Overlay Method for Multiple Sample LDH Isoenzyme Separation and Quantitation
Authors: Beals Daniel F , Stedman Enid , Kouns D Michael 
Published: January 2020

Abstract
A rapid microtechnic utilizing cellulose acetate membranes for the electrophoretic separation of LDH isoenzymes is described. The use of cellulose acetate for both migration and reagent application represents a relatively inexpensive and reproducible method which avoids many of the inherent problems associated with agar gels. The technic can be used for the analysis of a relatively large number of samples. Normal distribution values of the LDH isoenzymes were established.
A Kinetic Photometric Method for Serum γ-Glutamyl Transpeptidase
Authors: Szasz Gabor 
Published: January 2020

Abstract
A kinetic method is described for the determination of γ-glutamyl transpeptidase activity in serum. Optimal conditions for the reaction were ascertained, normal values in milliunits per milliliter at 25° established, and the reliability of the method examined. γ-Glutamyl-p-nitroanilide in ammediol-HCl buffer at pH 8.2 is employed as substrate. The method requires only 0.1 ml. of serum and, using an automatic cuvet positioner and recorder as well as an automatic diluter, more than 60 determinations can be carried out in 1 hr. On the basis of a large number of determinations, the method was shown to be technically excellent and clinically valuable.
A Rapid Method for Checking the Purity of Radioiodinated Human Luteinizing Hormone
Authors: Abraham Guy E 
Published: January 2020

Abstract
A method using dextran-coated charcoal has been used to check the purity of radioiodinated human luteinizing hormone. The results obtained by this method compared favorably with those obtained by the double antibody technic, which takes much longer to perform. The reliability of the method using dextran-coated charcoal is demonstrated and its practicability discussed.