bluuebunny/crossref_metadata_2025 huggingface dataset:
Simplified Method for the Estimation of Inorganic Phosphorus in Body Fluids
Authors: Goldenberg Harry , Fernandez Alberto
Published: January 2020

A simplified procedure is described for the determination of inorganic phosphate in body fluids. The method employs two stable reagents and requires a minimum number of steps. Serum is deproteinized with trichloroacetic acid containing ferrous ion and thiourea. The supernatant is decanted and mixed with a small volume of molybdic acid. The phosphomolybdate formed is immediately reduced in situ by the ferrous ion to produce a blue color that is stable for several hours. The intensity of color is insensitive to changes in concentration of acid, molybdate, ferrous ion, and thiourea, and to losses in decanting the serum supernatant. Excellent conformity to Beer's law is demonstrated over a wide range of phosphorus concentrations. Recoveries of phosphorus added to serum and urine are shown to be quantitative. A comparison is presented between this method and that of Fiske and SubbaRow (1).
Semiautomatic Pipetting Device (the Governor Pipet) for Clinical Chemistry Procedures
Authors: Harrison Norman B
Published: January 2020

An economic semiautomatic pipet is described with its applications. The accuracy of this pipet falls within the tolerances established by the American Chemical Society Committee on Micro chemical Apparatus.
A Multichannel Continuous-Flow Analyzer
Authors: Thiers Ralph E , Bryan Jean , Oglesby Katherine
Published: January 2020

A 10-channel analyzer is described with which sodium, potassium, chloride, carbon dioxide, calcium, phosphorus, total protein, albumin, albumin blank, and uric acid levels may be determined simultaneously. Operating at the rate of 60 specimens per hour, the instrument uses less than 1 ml. of serum for all 10 determinations. The results appear on 5 two-pen recorders. The report describes the instrument, its operating characteristics, modification of the sampler module to enable sampling from test tubes, a manual system of rapid data-handling, and the system employed for nearly anaerobic sample-handling.
Profile of Admission Chemical Data by Multichannel Automation: An Evaluative Experiment
Authors: Bryan D Jean , Wearne Judith L , Viau Alberto , Musser A Wendell , Schoonmaker Fred W , Thiers Ralph E
Published: January 2020

In an experiment comparing the clinical chemical data obtained for incoming hospital patients from samples of blood submitted to the routine laboratory and from samples analyzed automatically, a multichannel analyzer was employed. The constituents determined, chosen on the basis of the frequency with which they were ordinarily requested, were glucose, urea, sodium, potassium, chloride, carbon dioxide content, calcium, phosphorus, total protein, albumin, and uric acid. In a significant fraction of the patients admitted at three different hospitals the profile of admission chemical determinations indicated abnormal values which had not been sought by the physician and which often were of direct help to him and benefit to the patient.
An Improved Method for Determination of Serum Albumin and Globulin
Authors: Fernandez Alberto , Sobel Charles , Goldenberg Harry
Published: January 2020

A simple and reliable method has been developed for the analysis of serum proteins. Globulins are precipitated from serum with HCI- ethanol. The albumin remains in the supernatant fluid. The albumin fraction is then precipitated by alcoholic sodium acetate. The proteins are redissolved and determined colorimetrically following their reaction with the biuret reagent.

Recovery and electrophoretic studies indicate that the method affords a clean-cut separation of albumin from the globulin fraction. Lipemia does not appear to interfere with the analysis.
Solubility Determination of Cholesterol Polymorphs in Organic Solvents
Authors: Stauffer Royce D , Bischoff Fritz
Published: January 2020

In a study of the solubility of crystalline forms of cholesterol in various solvents, the solubilities (per cent by weight) of cholesterol needles and hydrated plates at 38° were, respectively, 4.0 and 3.2% in olive oil; 2.6 and 1.9% in tetradecane; 26.2 and 9% in toluene; and 21.0 and 7% in cyclohexane. When these solvents are in equilibrium with an aqueous phase, needles are converted to plates. Pseudomorph ( dehydrated) plates in olive oil have the solubility of needles. These differences may have significance in studies involving cholesterol pathogenesis.

The modified Zak reaction with ethanol could not be used for the assay of cholesterol in olive oil since the reaction product was turbid. Higher alcohols were studied as a substitute for ethanol; 2-propanol was satisfactory.
The Determination of Glutamine in Plasma and Urine
Authors: Preuss Harry G , Bise Bernard B , Schreiner George E
Published: January 2020

A method is described for determining the concentration of glutamine in plasma and urine. The procedure, which depends on the collection of ammonia, is mastered easily and requires materials commercially available.
Human Plasma and Serum Trypsin-like Esterase Activity
Authors: Rutkowski Roman B
Published: January 2020

A spectrophotometric method using benzoyl arginine ethyl ester (BAEE) is described for the assay of serum and plasma trypsin-like esterase activity. The method was used to find activities in serum and plasma (anticoagulated with oxalate and heparin) from 12 healthy males at 3 different reaction pH's.

The effects of calcium, oxalate, heparin, soybean trypsin inhibitor, ovomucoid, and heat on this activity were also measured. Values of esterase activity were significantly different, indicating a variable enzyme or inhibitor composition in the 3 sets of samples. Plasma from heparinized blood gave unique activity responses to pH and to the agents tested for effect.
Microdetermination of Protein Nitrogen with a Dumbbell Diffusion Apparatus
Authors: Nobel Deana
Published: January 2020

The use of a two-chamber, sealed microdiffusion apparatus has been investigated for the determination of protein nitrogen on samples containing 0.5 mg. protein. The apparatus is constructed from a ground-glass ball-and-socket joint, and all operations including digestion are performed in the designed apparatus. The method has been applied to the determination of nitrogen in tobacco mosaic virus protein and found to be in good agreement with theoretical values.
Automatic Method for the Determination of Calcium in the Presence of Magnesium and Phosphate Ions
Authors: Smith Preston , Kurtzman Caroline H , Ambrose Mary E
Published: January 2020

A direct spectrophotometric method for manual analysis of calcium using the indicator dye Eriochrome Blue S. E. was selected for automation. Most indicator dyes used have been somewhat unstable in solutions sufficiently alkaline to minimize the interference of magnesium. Eriochrome Blue S. E., when kept in an ice bath in the absence of light, permitted the use of sufficient alkali to remove interfering magnesium ions. Magnesium did not interfere in concentrations up to 12 mg./100 ml. when added to standards. The addition of 0.5% (w/v) citric acid removed interference of phosphate in concentrations up to 300 mg./100 ml.

The automated method has the advantage of speed, yet retains the accuracy and precision of the conventional methods used for determining calcium.
Serum Glutamic-Oxaloacetic Transaminase Activity: Diagnostic Accuracy of the Revised Spectrophotometric and the Dinitrophenylhydrazine Methods
Authors: Amador Elias , Franey Robert J , Massod Mary F
Published: January 2020

The diagnostic accuracy of two methods for measuring serum glutamic-oxaloacetic transaminase activity was examined in 50 cases of acute myocardial infarction proven by autopsy and in 12 nonfatal cases documented by rigid clinical criteria. All activities measured with the revised spectrophotometric method were elevated during the second day after infarction, and all patients had an elevated activity. The spectrophotometric method therefore had a diagnostic accuracy of 100%.

Activities measured with the dinitrophenylhydrazine method of Reitman and Frankel were elevated in only 68% of cases during the second day after infarction, and the activity was elevated in only 76% of all the patients during the first 4 days. Dinitro-phenylhydrazine-measured activities were therefore 20-30% inaccurate. The diagnostic inaccuracy of the dinitrophenylhydrazine method could result in 300,000 false-negative diagnoses of acute myocardial infarction each year in the United States alone.
Effect of a Nonionic Detergent on the Spectral Absorption of Oxyhemoglobin in the Presence of Bilirubin
Authors: Jackson Sanford H
Published: January 2020

The presence of the nonionic detergent Brij 35 in a solution of oxyhemoglobin and bilirubin has been found to change the spectral transmission curve of the oxyhemoglobin. The major change is in the 475 mµ region, where the transmission is greatly increased. A combination of the bilirubin with the oxyhemoglobin by an intermediate linkage with the Brij is postulated.
Automated Methods for Blood Glucose and Urea with Adaptation for Simultaneous Determination
Authors: Fingerhut Benjamin , Ferzola Rocco , Marsh Walton H , Miller Alfred B
Published: January 2020

Automated blood glucose and urea nitrogen procedures have been modified for use with the Technicon 15-mm. tubular flow-cell colorimeter to take advantage of the resulting increased sensitivity and economy. Flow diagrams for these procedures as well as for the simultaneous determination of glucose and urea are presented. Recovery and reproducibility data are given to indicate the reliability of these methods.
Studies of Some Indole Compounds Isolated from the Urine of a Mentally Retarded Child
Authors: Fischl J , Israel S
Published: January 2020

During the investigation of the urine of a mentally retarded child, a number of indole compounds were isolated. Gel filtration of the native urine gave three chief fractions. phatase fraction of blood had properties unlike that of the red blood cell enzyme and

Extraction methods available for the isolation of the abnormal indoles in large amounts resulted in irreversible structural changes, probably detachment of the carboxy groups, with loss of electrophoretic mobility, changes of chromatographic properties, and decreased water solubility.

It is presumed that the presence of the abnormal indoles isolated is the result of disturbed metabolism of the aromatic amino acids.
An Automated Method for the Determination of Serum Organic Iodine
Authors: Simpson D
Published: January 2020

The accuracy and reproducibility of an automated method has been assessed and the normal range for total serum organic iodine found to be 3.9-7.5 µg./10O ml., mean 5.7 µg./100 ml. Preliminary resin treatment of serum has been shown to be effective in removing normal concentrations of inorganic iodine. In the case of serums having grossly elevated inorganic iodine levels of up to 100 µ g./10O ml., the resin extracts more than 96% of the halide, but the unabsorbed iodine may invalidate the estimation. The resin can extract organic iodine from serum but the process occurs very slowly and it is of practical importance only if serums are allowed to stand over resin for longer than 24 hr.
A Convenient System for Esterification of Fatty Acids
Authors: Dryer Robert L
Published: January 2020

A compact apparatus for the methanolysis of lipids and esterification of fatty acids is described. The apparatus is designed to permit the complete preparation of small quantities of fatty esters, without sample transfer, for study by thin-layer or gas-liquid chromatography.
Applications of Computer Produced Frequency Distribution Curves
Authors: Ressler N , Whitlock L S
Published: January 2020

A method is described for determining the diagnostic significance of test results. It is based upon the relation of a test value to a frequency distribution curve of patients with a particular disease, and to a curve of others without that disease. When the two curves overlap at the test value found, the results are evaluated in terms of the probability of the patient corresponding to either of the two curves. The evaluation of results in terms of probabilities is more descriptive than the classification of all answers as either "normal" or "abnormal" and permits the combination of probabilities obtained from a number of tests into a single, resultant probability. The most probable diagnosis of a given patient, based upon all the tests done, or the most discriminating combination of tests for the diagnosis of any disease can be determined. The method permits compensation for such factors as a patient's age and sex, or the stage of a disease. It is nonparametric, and can be performed automatically with a data-processing system.
Determination of Calcium in Urine and Serum by Atomic Absorption Spectrophotometry (AAS)
Authors: Trudeau David L , Freier Esther F
Published: January 2020

The determination of calcium in biologic fluids by atomic absorption spectrophotometry is interfered with by the presence of protein, cations, and those anions that form complexes with calcium. Such interference was overcome when lanthanum was included in a 1:50 dilution of serum or urine. Recovery of calcium added to calcium-free serum was 100%. The S.D. based on double-blind duplicates was 0.22 mg./lOO ml. Excellent statistical agreement was found between the test method and each of the 2 reference methods.
Distribution Patterns of Uric Acid in Coronary Artery Disease
Authors: London Morris , Hums Mary
Published: January 2020

The uric acid levels in each of 335 cardiac patients were studied over a period of more than 3 months from the onset of the acute stage of coronary heart disease. Comparison was made with uric acid values obtained from a group of 316 normal subjects. Male patients with arteriosclerotic coronary artery disease with infarction generally exhibited rising concentrations of serum uric acid during the first weeks after an attack and a gradual return toward normal levels after 3 months. Female patients of the two groups studied and male patients with arteriosclerotic coronary artery disease, but without infarction, had uric acid levels averaging much higher than those of the control group.
Determination of Calcium and Magnesium in Serum, Urine, Diet, and Stool by Atomic Absorption Spectrophotometry
Authors: Gimblet Elizabeth G , Marney Amy F , Bonsnes Roy W
Published: January 2020

Atomic absorption spectrophotometry was evaluated as a method for the determination of calcium and magnesium in serum, urine, diet, and stool, and was found a most suitable technic for a large clinical chemistry laboratory.
Dumbbell-Diffusion Screening for Carbon Monoxide, Volatile Alcohols, and Chlorinated Hydrocarbons in Blood
Authors: Nobel Sidney , Ricker Alyne
Published: January 2020

Rapid screening tests for the detection of carbon monoxide, ethanol and other volatile alcohols, and chlorinated hydrocarbons in blood are presented. The dumbbell-diffusion cell used was found to be versatile in allowing reactions to be carried out at either room temperature or 1000 and in acting as a support for pretreated paper discs.
Gas Chromatography of Meprobamate
Authors: Maddock R K , Bloomer H A
Published: January 2020

Rapid detection and precise quantitation of meprobamate in biologic fluid has been accomplished using the gas chromatograph. The method described has proved useful in elvaluating patients intoxicated by this sedative.
Effects of Tomatine on the Colorimetric Determination of Cholesterol by the Zak Procedure
Authors: Eskelson Cleamond D , Dunn Arthur L , Cazee Clarence R
Published: January 2020

The iron-acetic acid reagent used for cholesterol determinations produces a color with tomatine, which is reported to be a more specific precipitant for cholesterol. To circumvent the interferen:e of tomatine found in a cholesterol-tomatinide complex, a standard solution containing stoichiometric amounts of tomatine and cholesterol was used and proved to be reliable for the determination of free cholesterol in serum.
A Rapid Spectrophotometric Method for the Determination of Citric Acid in Blood
Authors: Camp Bennie J , Farmer Lynette
Published: January 2020

A method is described for a determination of citric acid in serum. This method is based on the formation of pentabromoacetone from citric acid and subsequent color development with thiourea.
The Clinical Chemistry and Pathologic Physiology of Thyroid Tissue
Authors: Stanbury J B , DeGroot Leslie J
Published: January 2020

Familial goiter with hypothyroidism can be subdivided into at least 8 groups and each appears to result from an inherited disorder at a specific stage in thyroid hormone synthesis, mobilization, or peripheral effect. At times, the intense hyperplasia which accompanies one of these disorders evolves into malignant disease. Criteria for diagnosis of each are presented.
Enzymatic Abnormalities in Diseases of Sphingolipid Metabolism
Authors: Brady Rascoe O
Published: January 2020

Biochemical investigation employing labeled sphingolipids has become a useful technic for determining the metabolic lesions in the sphingolipidoses. With these procedures, specific enzymatic defects have been demonstrated in Gaucher's disease, Niemann-Pick disease, Fabry's disease, and in metachromatic leukodystrophy. As suitable substrates become available, this method will be useful for elucidating the nature of the lesions in Tay-Sachs disease and generalized gangliosidosis.

Enzymatic assays with labeled compounds performed on biopsy specimens from various tissues and white blood cell preparations have been helpful in establishing the diagnosis of the sphingolipidoses. Tissue cultures obtained from patients with Niemann-Pick disease show diminished sphingomyelin-cleaving enzyme as compared with control enzyme levels. Tests such as these should be of considerable diagnostic and prognostic usefulness, as well as being helpful adjuncts for the selection of proper therapeutic measures.
Continuous Spectrophotometric Measurement of Serum Alkaline Phosphatase Activity
Authors: Bowers George N , Kelley Mari-Lou , McComb Robert B
Published: January 2020

Findings with 9 self-indicating phenolic substrates for alkaline phosphatase assay by continuous spectrophotometric technic demonstrate that not only specific reaction conditions, e.g., buffer type, molarity, and pH, contribute significantly to the final observed "Sensitivity" attributed to any 1 substrate but also the following variables must be considered: (1) the enzyme's tissue and species source; (2) the molar absorptivity difference between the substrate and its dephosphorylated product; and (3) the molecular activity.
Sulfur Content of Paper Electrophoretic Fractions In Human Serum
Authors: Natelson Samuel , Stellate Rodney
Published: January 2020

Instrumentation is described for scanning paper electrophoretic strips for the sulfur distribution of the fractionated serum proteins with the vacuum X-ray spectrometer. Paper electrophoretic patterns of serum proteins scanned by X-ray spectrometry for sulfur content of the various fractions and by protein staining are compared.

For 26 blood donors, the mean percentages of sulfur found in the different fractions were: albumin, 1.64; and globulins: alpha1, 0.63; alpha2, 1.10; beta, 1.14; and gamma, 0.98. The procedure was then applied to the serum of patients with diseases of the liver and of the kidney, various types of malignancies, and other diseases.

The percentage of sulfur in abnormal fractions varies widely. This permits, in some cases, detection of abnormal peaks which would otherwise be missed by protein staining alone.

This technic should be of value in the identification and classification of abnormal protein fractions, when combined with studies by the ultracentrifuge and immuno-electrophoresis.
Determination of Neutral Urinary 17-Oxosteroids with Hydroxide of Hyamine 1O-X in the Zimmermann Reaction
Authors: Bjerre Solveig , Kita Rose
Published: January 2020

A modified method for 17-oxosteroid determination is described. The organic base, hydroxide of Hyamine lO-X,° which is stable in methanol, has replaced the unstable ethanolic potassium hydroxide solution in the Zimmermann reaction. Maximal color development was studied by varying incubation temperature, time, m-dinitrobenzene, and concentration of hydroxide of Hyamine 10-X. An incubation temperature of 37° for 30 min., with 1% m-dinitrobenzene in 1 M Hyamine 10-X hydroxide solution, gave close to maximal color.

The major urinary 17-oxosteroids, dehydroepiandrosterone, androsterone, and etiocholanolone, gave similar chromogenic values. However, C3 and C20 oxosteroids produced some color in the Zimmermann reaction, and thus if present in large amounts, interfere.

The interference in vitro of 35 drugs was tested, and several drugs were found to interfere.

An essentially pigment-free urinary extract was obtained during the washing step, by addition of water to the ethylene dichloride extract containing sodium hydroxide pellets.

Comparative 17-oxosteroid studies of urine specimens from laboratory personnel and from patients were performed, based on absorbance at a single wavelength (520 mµ) and at three wavelengths (Allen correction). Correlation coefficients for the laboratory personnel were .983 for females and .996 for males; for the patients, .974 and .975, respectively.
Automated Colorimetric Determination of Free Fatty Acids in Biologic Fluids
Authors: Dalton C , Kowalski C
Published: January 2020

For the routine determination of free fatty acids (FFA) the authors recommend a modification of the automated colorimetric method of Antonis (1) using the extraction procedure of ltaya and Ui (2). This direct extraction and automated analysis shows good correlation with Trout's (3) modification of Dole's (4) titrimetric procedure.
Measurement and Standard Reference Materials in Clinical Chemistry
Authors: Young Donald S , Mears Thomas W
Published: January 2020

The concepts of the measurement system based upon four parameters—length (meter), mass (kilogram), time (second), and temperature (kelvin)—are developed. The proper daily operation of an analytic laboratory depends upon these basic measurements and others derived from them, e.g., the liter. An additional component of chemical measurement which directly influences accuracy is the purity of the standards and reagents employed. The standard reference materials program of the National Bureau of Standards provides a central source of guaranteed high-purity reference materials which are available to all. The reliability of chemical measurements should increase as new standard reference materials such as cholesterol, uric acid, urea, and creatinine are utilized to standardize methods and to calibrate instruments in the clinical laboratories of this country.
Radioimmunoassay of Human Growth Hormone
Authors: Knoller Mechthilde , Tsao M U , Lowrey George H
Published: January 2020

Detailed methods for: (1) 131I iodination of human growth hormone (HGH); (2) purification of labeled HGH (HGH-131I; and (3) radioimmunoassay of HGH are given. Bio-Gel filtration is introduced as a rapid and reproducible method for purifying HGH-131I which has been obtained by a modification of the method of Greenwood et al. (1). Highly purified HGH-131I with a bindability of 96% or more is usually achieved.
Semiautomated Assay of Normal Concentrations of Urinary Glucose by an Enzymatic Fluorometric Technic
Authors: Scherstén Bengt , Tibbling Gunnar
Published: January 2020

A semiautomated, enzymatic, fluorometric method for the determination of the low glucose concentrations normally present in urine from subjects in the fasting state is described. The method is developed from a manual, enzymatic, fluorometric technic for the determination of urinary glucose using hexokinase (HK) and glucose-6-phosphate dehydrogenase (G-6-PDH). The procedure is based on measurements of the fluorescence of reduced nicotine amide adenine dinucleotide-phosphate (NADPH2) which is formed in proportion to the glucose content of the sample. The unspecific fluorescence of urine is almost completely removed by treating the urine with a mixed ion-exchange resin prior to applying the automated procedure. The chief advantage of the method is that it may afford an opportunity for low-cost screening for detection of bacteriuria.
Duodenal Fluid pH in Cystic Fibrosis
Authors: Knauff R E , Adams J A
Published: January 2020

Attention is directed here to the major discrepancies among duodenal fluid pH measurements in cystic fibrosis. A series of 9 cystic fibrosis and 9 control subjects were found to have duodenal fluid pH values of 4.8 ± 0.7 and 6.3 ± 0.2, respectively.
Urinary Glucose Measurement
Authors: Peterson John I
Published: January 2020

A method is described that appears to be more suitable for urinary glucose determination than the glucose oxidase, or any other method, and one that is reliable, accurate, and highly specific.
Analysis of Urine for Its Ultraviolet-Absorbing Constituents by High-Pressure Anion-Exchange Chromatography
Authors: Scott Charles D
Published: January 2020

An automatic, high-resolution analytic system for the quantitative determination of the ultraviolet-absorbing molecular constituents of urine and other body fluids is being developed. This system is comprised of a heated, high-pressure anion-exchange column for the separation step and a continuous-flow ultraviolet spectrophotometer for the detection step. Separation is achieved by elution with an acetate buffer of gradually increasing concentration. The total analysis time is 40 hr.

Chromatograms showing the absorbance of the column effluent as a function of time are recorded by a strip-chart recorder and by a data acquisition system containing a digital voltmeter and paper tape punch. The output from the latter is then used as the input to a digital computer for analysis of the chromatogram.

More than 140 chromatographic peaks have been resolved from a 2-ml. urine sample. Normal urine samples yield similar chromatograms. A variation in the diurnal cycle has been noted.
Observations on the Fluorometric Measurement of Creatine Kinase Activity
Authors: Sax Sylvan M , Moore John J
Published: January 2020

Twenty patients’ serums have been analyzed by both the Sax-Moore (1) and Conn-Anido (2) creatine kinase methods. No significant difference in enzyme activity was found. In our hands, the Conn-Anido procedure, as originally described, gave variable results and high background fluorescence. The presence of high alkaline or acid phosphatase activities in specimens analyzed by the Sax-Moore procedure does not cause spurious elevations of creatine kinase.
Hemiglobin and Hemiglobin Nitrite
Authors: van Assendelft O W , Zijlstra W G
Published: January 2020

Hemiglobin terminology as proposed by Theil and Auer (1) is inadequate. Equimolar quantities of nitrite and oxyhemoglobin give rise to the formation of hemiglobin. Excess nitrite causes the formation of hemiglobin nitrite.
Automated Method for the Determination of Deuterium Oxide in Water and Biologic Fluids
Authors: Robbins R C
Published: January 2020

An automated system has been assembled for determination of deuterium oxide in water and physiologic fluids. The system consists of an AutoAnalyzer sampler, proportioning pump, and dialyzer; a Perkin-Elmer infrared spectrophotometer; and a Sargent recorder. Reproducibility of peak heights showed a standard deviation of less than ± 1 mm. over a range of D2O concentrations from 0.125 to 1.000%.
Fluorometric Screening Procedure for Galactosemia Utilizing the AutoAnalyzer
Authors: Hochella Norman J , Hill John B
Published: January 2020

A screening procedure is described which can be used to separate the great majority of normal persons from those with a lack of the enzyme galactose transferase. The method is designed to be used on dried blood spot eluates which remain after a phenylalanine determination has been performed. The optimum conditions for this test are described, and data are presented from a preliminary study of more than a thousand infants and several confirmed galactosemics.
Determination of Thyroxine-Binding Globulin
Authors: Roberts R C , Nikolai T F
Published: January 2020

A method for determining thyroxine-binding globulin (TBG) concentration as the total thyroxine-binding capacity, has been developed. Prior electrophoretic separation of the three serum thyroxine-binding proteins is not required. Serum samples are diluted with a barbital-salicylate buffer pH 8.6, which inhibits thyroxine-binding by prealbumin. After incubation with 100 µg/100 ml thyroxine containing 131l-thyroxine, dextran-coated charcoal is added to the sample, which binds all the thyroxine not bound to TBG. The radioactivity in the supernatant solution is directly related to the concentration of TBG present. The Pearson’s correlation coefficient between the TBG results for this new assay and the polyacrylamide electrophoretic assay is 0.964. The mean TBG concentration and standard deviation for 80 normals was 19.2 ± 2.6 µg/100 ml. Pregnant women and women taking estrogens had a mean and standard deviation of 35.8 ± 4.8 µg/100 ml. Males from TBG-deficient families had TBG values of 5 µg/100 ml or less, and females from these families had values ranging from 8 to 12 µg/100 ml. The new assay is considerably simpler in equipment requirements and technic than the assays currently being used, and should be more practical for routine clinical laboratory use.
Butanol-Extractable Iodine in Human and Bovine Colostrum and Milk
Authors: Man Evelyn B , Benotti Joseph
Published: January 2020

High total iodine content and significant amounts of iodinated amino acids, but not of thyronines, have been reported in milk of various species. Since the human neonate requires thyroxine-like iodine compounds for central nervous system development, analyses of thyroxine-like iodine compounds such as butanol-extractable iodine of colostrum or early milk were indicated. Four samples of human milk 2-5 days post-delivery and 11 samples of bovine milk were examined for butanol-extractable iodine content. Thyroxine-like iodine compounds of colostrum or milk soon after parturition were extremely low, but total iodine values of milk supply abundant inorganic iodine for the mature neonatal thyroid.
Agar Gel Lipoprotein Electrophoresis: A Correlated Study with Ultracentrifugation
Authors: lammarino R M , Humphrey M , Antolik Paul
Published: January 2020

Interest in lipoprotein electrophoresis has been stimulated by a reappraisal of hyperlipoproteinemic syndromes and definition of five basic types according to Fredrickson (Types I, II, III, IV, V). The basic analytic reference for lipoprotein studies remains ultracentrifugal analysis. We have adapted an agar gel lipoprotein electrophoretic system employing a photometric scan and quantification of lipoprotein fractions based on post-electrophoresis Sudan Black B staining. This method of lipoprotein partitioning has been compared with lipoprotein analysis by ultracentrifugation. Statistically significant correlation between the methods is demonstrated.
Chemically Hardened Glassware
Authors: Wittrig John J , Anthony Edmund J , Woods A E , Coates John T
Published: January 2020

A source of error in lithium determinations from commonly used chemically hardened glassware is described. This contaminating source may contribute up to a thirty-fold error, depending on the levels being analyzed.
Cerate-Arsenite Measurement of Iodine in the Subnanogram Range
Authors: Hoch Hans , Lewallen Charles G
Published: January 2020

A method for the measurement of subnanogram quantities of iodine is described. Procedural detail and precision of results are presented for application of the method to protein-bound or total iodine in duplicate on 12.3 µl serum. Following wet ashing with chloric reagent, the iodine-catalyzed cerate-arsenite reaction was carried out at temperatures between 23 and 27°, and the reaction rate coefficients were corrected to refer to 25.0° by an empirical equation. The recovery of iodine standards, added to the precipitated protein before ashing, ranged between 96 and 106%. One contributing cause of this variation is the formation of an inhibitor of unknown nature during heating. Samples were brought to a final volume of 180 µl prior to fading. The detection limit was of the order of 0.04 ng iodine. For 62 serum samples having a mean iodine content of 0.558 ng (range 0.15-1.31 ng), the standard deviation calculated from duplicates was 0.019 ng/180 µl. For 31 samples having a mean iodine content of 2.24 ng (range 1.61-2.96 ng), the standard deviation was 0.039 ng/180 µl. Expressed as micrograms of iodine per 100 ml of serum, the mean ± standard deviation for the group of 62 samples was 4.54 ± 0.15.
Assay of Thyroxine-Binding Globulin by Polyacrylamide Electrophoresis: Normal Values
Authors: Roberts R C , Nikolai T F
Published: January 2020

Thyroxine-binding globulin (TBG) assays by the polyacrylamide electrophoresis assay of Nikolai and Seal have been carried out on 315 normal subjects. The assay was carried out with 200 µg exogenous labeled thyroxine per 100 ml added to the samples. The means and standard deviations for the three thyroxine-binding proteins in males (n = 140) were: TBG 19.7 ± 3.0 µg/100 ml, thyroxine-binding albumin (TBA) 38.0 ± 10.3 µg/100 ml, thyroxine-binding prealbumin (TBPA) 141.2 ± 10.9 µg/ 100 ml. The values for females (n = 175) were: TBG 21.6 ± 3.2 µg/100 ml, TBA 40.0 ± 10 µg/100 ml, and TBPA 137 ± 10.5 µg/100 ml. The difference in the means of the TBG values of males and females was significant (p < 0.01). Partial correlation analysis indicated that a significant correlation existed between protein-bound iodine and the TBG values only. A highly significant correlation was also found between the resin T3 uptake values and TBG. Persons (n = 43) receiving estrogens had a mean TBC of 36 µg/100 ml with a range of 26-45. This is an elevation of almost 5 SDs above normal. The normal values obtained by the polyacrylamide assay are compared with other electrophoretic assays of TBG.
Cleavage of Canavaninosuccinic Acid by Human Liver To Form Guanidinosuccinic Acid, a Substance Found in the Urine of Uremic Patients
Authors: Takahara Kihachiro , Nakanishi Shigeko , Natelson Samuel
Published: January 2020

Guanidinosuccinic acid (GSA) has been isolated in substantial quantities from the urine of uremic patients (1). Attempts to form this compound by transamidination from canavanine and arginine to aspartic acid were unsuccessful. A possible pathway has been found for GSA formation. Human liver homogenate splits canavaninosuccinic acid (CSA) to form homoserine and GSA. Optimum pH is at 8.7-8.8. The reaction proceeds best under anaerobic conditions. Reduced lipoic acid must be present for the reaction. NADH, NADPH, GSH, cysteine, ascorbic acid, NaCN, Fe++, and reduced CoA, dithiothreitol, and BAL cannot be substituted for the lipoic acid. BAL, NADH, NADPH, Fe++, and Co++ act as inhibitors for the reaction. A nondialyzable inhibitor also is present in the liver and can be washed out with water.

More than 90% of GSA incubated with various tissues and administered subcutaneously to intact rats was recovered unchanged. It is suggested that GSA is an end product of metabolism in the human.
Properties of "Usual" and " Atypical" Serum Cholinesterases Using o-Nitrophenyl Butyrate as Substrate
Authors: Whittaker Mary , Hardisty C A
Published: January 2020

The effects of varying concentrations of sodium chloride and formaldehyde on the activity of "usual" and "atypical" serum cholinesterases using o-nitrophenyl butyrate as substrate have been examined. The atypical enzyme has been shown to be more sensitive to either inhibitor than the usual enzyme. These results indicate two new methods for differentiating the two variants using a noncholine ester as substrate. Differential inhibition of the two enzymes by sodium chloride has been shown to be temperature-dependent.
A New "Kinetic" Method for Enzyme Analysis Suitable for Automation
Authors: Trayser Kenneth A , Seligson David
Published: January 2020

A method is proposed for automatic instrumentation of enzyme activity determinations which involve spectrophotometric measurements. The procedure utilizes a kinetic method to produce one instrumental reading that is proportional to enzyme concentration. The single spectrophotometric reading can be processed by analog or digital computation, using the known absorptivity constant of the reactant or product measured, to provide a value for enzyme activity expressed in micromoles of substrate consumed or product formed per unit time per unit volume under the specified conditions. Using the spectrophotometric measurement, one can establish enzyme concentrations based on absolute constants yielding results similar to those obtained by conventional kinetic measurements of zero-order reaction rates which are proportional to enzyme concentration.
Urinary Amino Acid and Peptide Excretion Patterns in Patients with Muscular Dystrophy (Duchenne): A Preliminary Study with the AutoAnalyzer
Authors: Maskaleris Milton L , Gross Stanislaw , Milhorat Ade T
Published: January 2020

An amino acid AutoAnalyzer was used to monitor the excretion patterns of the urinary amino acids and peptides of 7 male patients (aged 3-17) with muscular dystrophy of the Duchenne type. In comparison with the output of 8 healthy boys (aged 3-12), on the average, a reduction in the excretion of Thr, Ser, Gly, Ala, Val, Ile, Tyr, Lys, and His over a 24-hr period was found in the urine of the patients, although the number of analyses was too small for statistically significant conclusions. The content of Asp, Glu, Phe, and Leu was about equal, and Pro and Hyp were present in very small quantities. Also, for the first time, a peptide analyzer was used to study the bound components from urine specimens of the patients. Excretion patterns of several peptides in three of the above patients aged 3-17 were found to differ from those of the controls. Of the six major peptide fractions examined, five were present in smaller amounts in the urine of patients; only one was elevated. It appears from these preliminary results that further study of the excretion patterns of amino acids and peptides of dystrophic patients is worthwhile, and that study of the peptides should be given preference.
Immunologic Determination of Proteins Found in Low Concentrations in Human Serum
Authors: Becker W , Schwick H G , Störiko K
Published: January 2020

Of 42 well-characterized proteins of human blood plasma, 23 previously have been determined by quantitative immunochemical methods. Quantitative data on an additional 10 plasma proteins are now communicated. Antiserums against the following proteins have been prepared: α1B-glycoprotein (easily precipitable α1-glycoprotein). α1T-glycoprotein (tryptophane-poor α1-glycoprotein), α1-antichymotrypsin (α1X-glycoprotein), α2-antithrombin (antithrombin III), Zn-α2-glycoprotein, α2-neuramino-glycoprotein (C'1 esterase inhibitor), β2-glycoprotein II and III, γD-globulin.

These proteins were determined in normal human serums by applying radial immunodiffusion. Highly purified and physicochemically well-defined proteins were used as standards. Coagulation factor XIII (fibrin-stabilizing factor) was determined immunochemically in normal plasma using a specific antiserum. A genetically determined deficiency of β2-glycoprotein I has been found in healthy individuals. As yet, no conclusions on the biologic function of this protein can be drawn from the results. The available data on physiologic function and pathophysiologic abnormalities of all proteins mentioned are discussed.
Determination of Caffeine in Serum and Urine
Authors: Routh J I , Shane N A , Arredondo E G , Paul W D
Published: January 2020

The method of Axelrod and Reichenthal for the determination of caffeine in serum and urine was modified. The benzene used in the extraction of caffeine was shown to alter the spectral absorbance curve of this compound. A method based on the differential absorbance spectrums of caffeine and related compounds is described. Both methods exhibited satisfactory replication, recovery of added caffeine, and comparable serum levels of the drug.
A Membrane for the Rapid Concentration of Dilute Protein Samples in an Ultrafilter
Authors: van Oss Carel J , McConnell Cathryn R , Tompkins Russell K , Bronson Paul M
Published: January 2020

The preparation of an anisotropic membrane which retains all proteins of a molecular weight of 25,000 and larger is described. It permits, with the help of appropriate ultrafiltration cells, the 400-fold concentration of 400 ml of a dilute protein solution within a few hours, avoiding all denaturation. Ultrafiltration with this membrane has been compared with a tannic acid precipitation method for the concentration of very dilute serum protein solutions. The ultrafiltration procedure resulted in a more representative recovery of the proteins that were present in the original undiluted sample, with quite fair yields. Some results are given on the proteins found in urine samples from normals and patients with disease.
An Improved Spectrophotometric Method for Determination of Total 3-Methoxy-4-Hydroxyphenylglycol in Urine
Authors: Nicholas Nickie L , Brown Harold , Swander Anna M
Published: January 2020

A clinically useful spectrophotometric method for the determination of 3-methoxy-4-hydroxyphenylglycol (MHPG) is presented. After treatment with barium chloride, the urine is hydrolyzed with Glusulase (β-glucuronidase and sulfatase).† The hydrolysate is passed through a column of Amberlite CG-4B‡ to remove any 3-methoxy-4-hydroxymandelic acid (MHMA) and the pH is adjusted to neutral. The MHPG is extracted with ethyl acetate and returned into potassium carbonate solution. Conversion of the MHPG to vanillin is accomplished with periodate and the vanillin is subsequently extracted with toluene and then potassium carbonate solution. The vanillin concentration is determined at 360 nm and 380 nm. The mean recovery of added MHPG standard was 54.9%. The mean daily excretion of MHPG in 23 samples from 10 normal subjects was 1.87 ± 0.6 mg (range 0.81-3.64). In 3 subjects with pheochromocytoma the excretion of MHPG was markedly elevated. There was an excellent correlation of the MHMA and MHPG excretion.
Laboratory Application of the Dextran-Coated-Charcoal Radioimmunoassay of Insulin
Authors: Poznanski Nadine , Poznanski Wojciech J
Published: January 2020

A modification of the method for radioimmunoassay of insulin is described, which achieves satisfactory sensitivity while employing commercially available reagents and antiserums. These modifications consist mainly in lowering the initial percentage binding, reducing the amount of labeled insulin, and preincubating the unlabeled hormone with antiserum. Application of the linear isotope dilution formula, modified for our conditions, proves to be a reliable substitute for the standard curve.
Prenatal Diagnosis of Lipid Storage Diseases
Authors: Brady Roscoe O
Published: January 2020

The antenatal diagnosis of all nine known sphingolipid storage diseases is feasible at the present time. To ensure maximum reliability for such important determinations, radiolabeled lipids should be used for detecting fetuses with Niemann-Pick disease, Krabbe's disease, and ceramide lactoside lipidosis. Various artificial substrates may be used with confidence to detect metachromatic leukodystrophy, Fabry's disease, the classic and variant forms of Tay-Sachs disease, and Gaucher's disease.
Research by Clinical Chemists in the United States
Authors: Rice Eugene W
Published: January 2020

Publications listed in Chemical Abstracts (1962-1966) for 1539 members of the American Association of Clinical Chemists have been analyzed statistically by the "Product of Factors Law" as developed by Zener to assess research productivity. The observed data agreed well with a theoretical distribution curve for research productivity derived from the use of seven individual, uniform, statistically independent factors. The three personal factors of success in research productivity are tentatively identified as curiosity, ability to learn, and intellectual vigor. Adequate time, facilities, and technical help, and the presence of stimulating colleagues are possible extrinsic environmental factors governing the characteristic productivity distribution curve observed in this study. During this period, about 65% of the AACC membership had no papers abstracted in Chemical Abstracts and not more than 50 averaged one or more papers per year. Various prevailing scientific and sociological trends are discussed, which soon may improve this perspective.
Correlation between Results of a New T-3 Test and the Percentage of Free Thyroxine in Serum
Authors: Leonards Jack R
Published: January 2020

A new "T-3" test, based on the competition between serum-binding proteins and Sephadex G-25 for 125I-triiodothyronine, is presented. Results obtained with this commercially available system (TRILUTE) compare favorably with those obtained either by direct measurement of percentage of free thyroxine or by the resin sponge uptake method. The described system requires less time and less plasma (0.05 ml), and the Sephadex column is disposable. Since the results of the T-3 test with TRILUTE and those for the percentage of free thyroxine correlate well, results obtained with the TRILUTE system can validly be converted to percentage of free thyroxine.
Detection of Basic Organic Drugs and Their Metabolites in Urine
Authors: Bastos Milton L , Kananen Gerald E , Young Randolph M , Monforte Joseph R , Sunshine Irving
Published: January 2020

Basic organic drugs were extracted into ethanol from urine saturated with potassium carbonate. Drugs in this concentrate were purified by extraction into ether at pH 8.5. The ether extract was evaporated and applied to several thin-layer chromatograms. Functional-group detection was used in qualitative and semiquantitative analysis of the developed chromatograms by spraying the plates sequentially with several group-specific reagents. This simple, sensitive, and inexpensive procedure permits simultaneous analysis of many samples. It is well suited for detection of drug abuse.
Biological and Analytic Components of Variation in Long-Term Studies of Serum Constituents in Normal Subjects
Authors: Williams George Z , Young D S , Stein Mervyn R , Cotlove Ernest
Published: January 2020

A study of blood constituents in normal individuals was undertaken to (a) estimate the contribution of biological and analytical factors to the variation of constituents over an extended time period; (b) to explore whether such tests can be used to derive meaningful personal blood "profiles"; and (c) to determine when analytic variation may become large enough to assume medical significance. This first paper describes procedures for subject selection, the laboratory methods employed, and evaluates analytic standard deviations. A group of 68 normal subjects was selected after medical evaluation. Sera were collected and analyzed in duplicate weekly for 10 to 12 weeks. Analytic deviation was estimated from the results of concurrent daily analyses of sterile pools of human serum. Laboratory procedures were introduced to reduce analytic deviation and to allow more accurate estimation of biological components of variation within and among individuals.
Correlation between Triglycerides and Glutamic-Pyruvic Transaminase in Men on High-Fat Diets
Authors: Katchman Bernard J , Zipf Robert E
Published: January 2020

Of eight young men on high-fat diets (60% of caloric intake) for 42 days, four developed serum glutamic-pyruvic transaminase concentrations greater than normal, while lactic dehydrogenase, glutamic-oxalacetic transaminase, and alkaline and acid phosphatases were within the normal range. Serum triglyceride levels were also within the normal range, but significant correlations between serum triglycerides and glutamic-pyruvic transaminase levels were found in six of the eight subjects; the mean values for all eight subjects showed a correlation significant at the 99% level of confidence. SGPT levels may be of fundamental significance along with blood triglycerides in the evaluation of fatty livers and coronary artery disease.