bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Colorimetric Method for Assay of Amphetamines in Urine
Authors: Frings Christopher S , Queen Cecelia , Foster Lowell B
Published: January 2020

The increasing abuse of drugs makes it imperative to have rapid, selective methods for their detection. Methods for amphetamines in which methyl orange is used as a reagent are subject to interference by a number of drugs. In the present modified, improved method, amphetamines combine with methyl orange to form a chromogen that follows Beer’s law at 515 nm to amphetamine concentrations of 10 mg/100 ml. Most interfering drugs are removed by pre-extraction into chloroform at pH 5.5. Of over 40 commonly used drugs, including organic bases and alkaloids, only amphetamine, dextroamphetamine, methamphetamine, and pentazocine HCl ("Talwin") react to produce a chromogen in this method. Recovery of amphetamine added to serum and urine is essentially 100%, as compared with aqueous standards taken through the entire procedure. The coefficient of variation is 8.9%. The method described, far more (but not completely) selective for amphetamines than previous methyl orange methods, is rapid, precise, and sensitive, which makes the method valuable in drug abuse screening programs—for which the speed is even greater, because only information on the qualitative presence or absence of amphetamines is required.
Automated Dithionite Test for Rapid, Inexpensive Detection of Hemoglobin S and Non-S Sickling Hemoglobinopathies
Authors: Nalbandian Robert M , Nichols Bruce M , Camp Frank R , Lusher Jeanne M , Conte Nicholas F , Henry Raymond L , Wolf Paul L
Published: January 2020

Automated adaptations of dithionite and urea—dithionite tube tests are accurate, reliable, inexpensive methods for detecting hemoglobin S. More than 3,000 individuals have been screened (120 determinations per hour; reagent cost, 2 to 4 cents per test). The dithionite reagent consists of potassium phosphate, sodium dithionite, and saponin. When S hemoglobin contacts this reagent, the red cells lyse, and the hemoglobin deoxygenates and sickles, forming a hydrophobic-bond-dependent nematic liquid crystal system that is manifested as turbidity. The resulting AutoAnalyzer curve is strikingly and diagnostically different from that produced by hemoglobin A in the same reagent. Specificity of the automated dithionite test may be enhanced by use of the automated urea—dithionite test, which consists of a specimen set of two aliquots: one traverses a dithionite line, the other a urea—dithionite line. A comparison of transmittance in the two lines yields typical diagnostic curves because the urea disperses the sickling, with a consequently increased transmittance over that of the dithionite aliquot. Methods are discussed for recognizing non-S sickling hemoglobins and a few other rare hemoglobinopathies.
A Modification of the "Sickledex" Test for Hemoglobin S
Authors: Powell James B , Beach Douglas J
Published: January 2020

The "Sickledex" test for hemoglobin S has been modified by the use of "Microtiter" plates and microliter sampling equipment. For screening purposes the testing procedure is faster, with significant glassware savings and a 10-fold decrease in sample and reagent requirements. Results are identical to those of the standard Sickledex test.
Automated Simultaneous Turbidimetric Determination of Cholesterol in β- and pre-β-Lipoproteins
Authors: Lopez A , Vial R , Gremillion L , Bell L
Published: January 2020

An automated method is described for simultaneously determining cholesterol in serum β- and pre-β-lipoprotein fractions. This fast, reproducible, accurate method depends on the ability of β- and pre-β-lipoproteins to form insoluble complexes with polyanionic polysaccharides such as heparin. Values obtained by this method and by similar manual methods described in the literature agree well. This method is extremely useful in mass screening for hyperlipidemias; in certain cases it may be more useful than the determination of only cholesterol or triglycerides.
Interaction of Chlorpromazine with Bile
Authors: Clarke A E , Denborough M A
Published: January 2020

Chlorpromazine causes precipitation both of the glycoprotein and protein components of bile in vitro. The reaction depends on an electrostatic interaction between the negatively charged carboxyl groups on the bile components and the positively charged amine groups on the drug molecules in solution. The optimum conditions for the interaction between chlorpromazine and bile components have been established, and the suggestion is made that this precipitation may be responsible in part, for cholestatic jaundice associated with the administration of chlorpromazine.
Routine Gas—Liquid Chromatographic Method for Simultaneous Assay of Major Urinary 17-Ketosteroids, and Pregnanediol and Pregnanetriol
Authors: Holub William R
Published: January 2020

Many methods of urinary steroid analysis have been used in evaluating endocrine function. Individual determination of particular metabolites and functional group analysis of steroid groups frequently involves extensive isolation and correction for interferences. By utilizing the separative and quantitative capabilities of gas-liquid chromatography, we have developed a method for the simultaneous analysis of certain clinically significant urinary steroids. Each analytical step has been made optimal, resulting in a simple and rapid method for determining these steroid metabolites in urine. Although it is a good technique for isolating and concentrating steroid conjugates, ammonium sulfate precipitation of the steroid conjugates is frequently unnecessary. Use of sulfatase and glucuronidase provides the most efficient and "clean" hydrolytic procedure.
Sodium Thymolphthalein Monophosphate: A New Acid Phosphatase Substrate with Greater Specificity for the Prostatic Enzyme in Serum
Authors: Roy A V , Brower Mary E , Hayden Jean E
Published: January 2020

We describe the use of sodium thymolphthalein monophosphate as a substrate for measuring acid phosphatase activity in serum. Thymolphthalein is liberated in the reaction and is conveniently measured by increasing the pH of the medium, which produces a color and also stops the hydrolysis. Optimal conditions for enzymatic activity were defined for use in the final assay system. Purified acid phosphatase isoenzymes from various human tissues and sera from patients with nonprostatic diseases most likely to affect serum acid phosphatase activity were used to show that the new method is more specific for the prostatic enzyme than other commonly used procedures for acid phosphatase. Other advantages include simplicity, good sensitivity over a wide range of activity, high precision, zero-order kinetics to about 200 times the upper limit of normal, easy standardization by a pure standard, and reagent stability.
Evaluation of a Spectrophotometric Method for Determination of Total Fecal Lipid
Authors: Fales Frank W
Published: January 2020

A spectrophotometric method is evaluated for determination of total fecal lipid. Duplicate samples of fecal homogenate, an appropriate standard, and a blank, each in acidic, aqueous alcohol, are extracted with petroleum ether. The extracts are analyzed by the spectrophotometric, acid-dichromate oxidation method. The procedure is much briefer and simpler than current gravimetric and titrimetric methods for fecal fat, and a comparative study suggests that the values obtained are of equal diagnostic value to those obtained by the popular Van de Kamer [J. Biol. Chem. 177, 347 (1949)] method for total fatty acids. Fecal samples from patients with various degrees of steatorrhea gave results having a linear relationship between total lipid and total fatty acid excretion (coefficient of correlation, 0.995; regression formula, total lipid = 1.09 (total fatty acid) + 3.4). The slope of near unity indicates that the increased lipid excretion in steatorrhea is almost wholly accounted for by increased triglyceride and fatty acid excretion and that the unsaponifiable fraction remains relatively constant.
Serum Glutamic—Oxaloacetic Transaminase: Evaluation of a Coupled-Reaction Enzyme Assay by Means of Kinetic Theory
Authors: Russell C D , Cotlove E
Published: January 2020

Rate equations and rate parameters are determined for the coupled-reaction assay for serum glutamic-oxaloacetic transaminase in which malic dehydrogenase is used. These are used to interpret observed curves of absorbance vs. time, to select optimum substrate concentrations, and to estimate nonrandom analytical errors. A simple, systematic, general approach is presented, which can readily be applied to other enzyme assays in which two or more reactions are coupled. It depends for its simplicity on access to an adequate computing facility.
Serum Amylase Activity in Liver Disease
Authors: Bhutta Izharul Hasan , Rahman M Ataur
Published: January 2020

Serum amylase activity was measured in 15 normal persons and in 60 liverdisease patients. Impairment of liver was assessed by serum bilirubin and thymol turbidity values. Most of the patients had serum amylase values that were well below the normal limits. Amylase activities were related to the degree of liver dysfunction, and serum amylase decreased as the bilirubin and turbidity values increased.
Studies on Leukocyte Phosphatases. III. Inhibition of Leukocyte Acid Phosphatase by Zinc
Authors: DeChatelet Lawrence R , Cooper M Robert , McCall Charles E
Published: January 2020

Whereas the activity of leukocyte alkaline phosphatase is stimulated by Zn2+, it inhibits acid phosphatase activity. The degree of inhibition of acid phosphatase depends on the pH of the medium, being greater as the pH approaches neutrality. This inhibition may be at least partially reversed by the addition of amino acids, which suggests that interactions of Zn2+ and amino acids may play an important role in regulating the overall phosphatase activity of the leukocyte.
A Facilitated Fractionation of Stable Urinary Estrogens before Their Automated Fluorometric Assay
Authors: Strickler Herbert S , Petty Judith M , Stanchak Patricia J
Published: January 2020

Urine samples to be assayed for estrone, estradiol-17β, and estriol are processed as usual: hydrolysis, ether extraction, and saponification, as well as partition between toluene and alkali. The samples are purified further, fractionated, and assayed by connecting columns containing Sephadex LH-20 to the sample line of an automated system for fluorometric assay. With this procedure, a sample can be fractionated and assayed every 45 min.
Rapid Fluorometric Assay of Estrogen Conjugates in Pregnancy Urine
Authors: Lee Leonie , Hähnel Roland
Published: January 2020

A rapid assay for estrogen conjugates in pregnancy urine is described. It involves extraction of the estrogen conjugates with Amberlite XAD-2, Kober reaction, and fluorometry of the dichloroethane extract of the reaction mixture.
Application of Fe(II)-5-Pyridyl Benzodiazepin-2-ones to the Determination of Plasma or Serum Glucose
Authors: Klein Bernard , Lucas Lois B
Published: January 2020

A new coupled redox procedure has been developed for the determination of glucose in 4 µl of plasma or serum. The photometric endpoint is formation of the violet-blue Fe2+-5-pyridyl benzodiazepin-2-one chelate, for which the absorbance at 580 nm is linear with glucose concentration from 25 to 300 mg/100 ml. Results obtained by the present technique and those obtained by the o-toluidine method and a glucose oxidase method agree well. The mean recovery of glucose added to plasma is 96.6% (range: 92.1-99.6%).
Rat Carcass Calorie Contents as Estimated from Fat and Nitrogen Analyses, Compared with Ballistic Bomb Calorimeter Data
Authors: Keller G H M , Schouten F J M , Dalderup L M
Published: January 2020

Measurements with the ballistic bomb calorimeter do give results that are in good agreement with the conventional measurements of fat and nitrogen content followed by the appropriate calculations, and are appreciably less time consuming.
A Simple Method for Separate Determination of Delta4- and Delta1,4-Corticosteroids in Urine
Authors: Uete Tetsuo , Shimano Noriko
Published: January 2020

Ethanolic solutions of Δ4- and Δ1,4-3-ketosteroids absorb ultraviolet light most strongly in the region of 240 nm, but, as sulfuric acid is added in increasing concentrations, absorption decreases. With sulfuric acid concentrations greater than 40 ml/100 ml of ethanol, the Δ4-3-ketosteroids show an absorption peak at about 290 nm, giving an isosbestic point in the region of 275 nm. However, Δ1,4-3-ketosteroids develop the absorption maximum at around 260 nm with the isosbestic point in the region of 250 nm. This bathochromic shift in ultraviolet absorption was used to separately determine Δ4- and Δ1,4-corticosteroids in urine. Urine is extracted with chloroform or methylene chloride. The extract is purified by chromatography and dissolved in H2SO4:ethanol(1:1, by volume). Ultraviolet absorption is measured at 220, 260, and 300 nm for Δ1,4-corticosteroids such as prednisolone or prednisone; at 250, 290, and 330 nm for Δ4-corticosteroids. The readings are corrected by Allen’s method [J. Clin. Endocrinol. Metab. 10, 71 (1950)] and the amount of steroid is estimated.
Studies on Leukocyte Phosphatases
Authors: DeChatelet Lawrence R , Volk James V , McCall Charles E , Cooper M Robert
Published: January 2020

The activity of leukocyte alkaline phosphatase is inhibited by a number of amino acids, most notably cysteine and histidine. The mechanism of this inhibition involves chelation of Zn2+ by the amino acids, as indicated by the complete reversal of the inhibition by added Zn2+. The concentrations of amino acids and Zn2+ required to affect the enzyme activity are such that their interaction might represent an in vivo mechanism for the control of leukocyte alkaline phosphatase activity.
Ethanol in Brain, as Assayed by Microfluorometry
Authors: Perez Vernon J , Cicero Theodore J , Bahn Barbara A
Published: January 2020

Gas—liquid chromatography (GLC), the technique most often used to measure ethanol in body fluids, is not practical for determining ethanol in tissues. Previously described fluorometric assays were modified for the enzymatic measurement of ethanol in brain and, for comparison, in blood of rats 1 h after intraperitoneal injection of 2.0 g of ethanol per kg of body weight. Mean ethanol content of brain was 23.43 mmol/kg and of blood, 24.18 mmol/ liter. Accuracy of the method was verified by GLC of the blood samples, which gave a mean ethanol content of 24.29 mmol/liter. No endogenous ethanol was measurable fluorometrically or by GLC in blood or brain samples from control animals injected with physiological saline solution (9 g/liter). Because samples of only 1 µl are required, the procedure is particularly useful when ethanol is to be measured in minute brain samples or when only very small volumes of blood are available.
Paper-Electrophoretic Method for Estimating Urocanic Acid in Urine
Authors: Barbieri Domênico , da Silva Iracema Alencastro , Nicolau José
Published: January 2020

A paper-electrophoretic method is proposed for determining urocanic acid in urine. Formiminoglutamic acid can be simultaneously estimated. Data are given for the urocanic acid content of urine from normal persons after a histidine load.
Ketosis Causing Spurious Elevation of SGOT Values
Authors: Wolf Paul L , Langston Claire , Potolsky Abraham I , Williams Dorothy J
Published: January 2020

In two patients, spurious enhancements of SGOT on SMA 12/60 determination caused erroneous diagnoses of liver disease, which could have led to potentially hazardous diagnostic measures. Such errors can be avoided by an ultraviolet spectroscopic check of suspect SGOT values.
High-Voltage Thin-Layer Electrophoretic Method for Detecting Histidinemia
Authors: Newton Dale A , Summer George K
Published: January 2020

A high-voltage thin-layer electrophoretic method is described for separating urinary histidine and imidazoleacetic, imidazolelactic, and imidazolepyruvic acids. The procedure provides a reliable confirmation of the diagnosis of histidinemia.
Macroamylasemia: Rapid Detection Method
Authors: Fridhandler Louis , Berk J Edward , Ueda Masatoshi
Published: January 2020

A reliable method is presented for rapidly screening human sera to detect macroamylasemia. A mixture of the serum to be tested, Blue Dextran, and cytochrome c is filtered through a small column of cross-linked dextran gel (Sephadex G-100). Amylase in the effluent fractions is detected by incubation with amylose and subsequent addition of iodine. Macroamylase, if present, is found in the blue-colored fractions, while amylase of normal molecular weight appears in the fractions colored by cytochrome c.
Simple Assay for Urinary Estrogens in Nonpregnancy
Authors: Chu T M , Osawa Yoshio , Reynoso Gustavo
Published: January 2020

A simple procedure is described for the selective extraction of urinary estrogens by concentration on XAD-2 resin and elution with ethanol:water (30:70, by vol). Fractionation of estrogens, with high sensitivity and good recovery, from urine of nonpregnant individuals is made possible by combined use of XAD-2 resin extraction and gas—liquid chromatography.
Rapid Method for Protein Quantitation by Electroimmunodiffusion
Authors: Gill Charles W , Fischer Craig L , Holleman Carolinda L
Published: January 2020

In the electroimmunodiffusion method described, a Mylar-backed cellulose acetate membrane plate is used as a support medium. Results are obtained faster, less preparation time is required, and the method is less expensive because less antisera is needed. Results with the method are reproducible (CV, 5%), correlate well with results by the single radial immunodiffusion method, and sensitivity is similar to the electroimmunodiffusion method in which agar gel is used as a support medium.
Method for Quantitative Measurement of Xanthurenic Acid in Urine
Authors: Wallace Mary Jean , Vaillant Henry W , Salhanick Hilton A
Published: January 2020

A method is reported for determining urinary xanthenuric acid (XA), a metabolite of tryptophan. XA is extracted from urine with isobutanol (2-methyl-1-propanol), transferred to ammonium hydroxide, and separated from other urinary metabolites on thin-layer cellulose plates with use of 0.2 acetate buffer, mol/liter, pH 5.4. The XA is measured spectrophotometrically after diazotization with 2-chloro-4-nitroaniline. The method, which is specific for XA, can be used to measure amounts as low as 0.4 µg/ml of urine. It has a range from 0 to 24 µg/ml, and results within this range are reproducible within approximately ±5%. Data obtained by this procedure are comparable to results reported for other methods.
Determination of Tissue Calcium by Nondestructive Neutron Activation Analysis
Authors: Livingston Hugh D
Published: January 2020

A method is described for measuring the concentration of calcium in arterial tissue by neutron activation analysis. The principal advantage is that the method is nondestructive and is ideal for analytical situations in which multiple biochemical measurements are required on a few-milligram sample. Application of the method is illustrated here by a study of aortic calcium metabolism in pigeons and monkeys being used as animal models in experimental atherosclerosis studies. The determination is made on irradiated dry fat-free tissue by using 49Ca (T½, 8.8 min) to measure calcium. The interference of 37S with the measurement is insignificant. Neutron activation data from one set of tissues were compared with data obtained by atomic absorption spectrophotometry in the same tissues. Good relative agreement was found, although results by atomic absorption were slightly systematically higher than those by neutron activation. Reasons for this are discussed.
A Systems Analysis of GEMSAEC Precision Used as a Kinetic Enzyme Analyzer
Authors: Maclin Ernest
Published: January 2020

Use of the GEMSAEC as a kinetic enzyme analyzer has been one of the most promising applications for this instrument. Several important variables must be defined if a practical system and components are to be developed for use in the clinical laboratory. The effect and inter-relationship of four of these are defined and analyzed to determine their impact on the precision of GEMSAEC: starting absorbance of the sample—reagent mixture, rate of change of absorbance, length of time for which the linear kinetic reaction progresses, and the uncertainty of the analog-to-digital conversion combined with electronic noise. A set of curves is generated from equations derived to demonstrate the coefficient of variation based on these variables. The influence of these variables, as compared to the variations of sample and reagent addition and of temperature control, is also briefly reviewed. The performance of the ENI GEMSAEC against these errors is summarized. The techniques described also define a convenient and practical way to evaluate the limits of precision that can be expected from analyzers for kinetic analysis based on the rate of the reaction rather than on a specific chemical determination.
Feasibility of Multiple Simultaneous Enzyme Assays, for Diagnostic Purposes, with the GeMSAEC Fast Analyzer
Authors: Tiffany Thomas O , Johnson George F , Chilcote Max E
Published: January 2020

The GeMSAEC fast analyzer provides the clinical chemistry laboratory with an analytical instrument that can be used to perform large numbers of kinetic enzyme analyses. Precise enzyme-rate analyses can be done routinely, on a large scale, and at a decreased cost per test. Improved precision in analyses of enzymes should provide more reliable data because analytical variation is lessened. We have asked how the fast analyzer might provide more useful diagnostic information to the clinician. We have selected the ratio of SGOT to SGPT activity in serum as an example, and examined instrumental precision. The coefficients of variation of the ratio, determined in the range of 50 and 140 Karmen units (which represents slightly elevated to clearly elevated values), are 4.8% and 2.2%, respectively. We examined the feasibility of measuring two or more enzyme activities simultaneously in one sample, to produce a diagnostic enzyme profile. Determination of SGOT, SGPT, and GLDH in parallel is presented as an example. In addition, we illustrate spectrophotometric linearity at 340 nm and discuss instrumental noise and an experimental approach to determining it by use of a premix experiment.
A Small, Automated High-Resolution Analyzer for Determination of Carbohydrates in Body Fluids
Authors: Katz Sidney , Dinsmore Stanley R , Pitt W Wilson
Published: January 2020

An improved automated, high-resolution anion-exchange analyzer has been developed for detecting and quantifying carbohydrates in body fluids. This new analyzer is more sensitive than the earlier model and much simpler to construct, operate, and maintain. Improved compact components include an electrically heated, folded 0.22-cm-i.d. anion-exchange column, a miniaturized color-development system that does not use a pump, and a miniature flow colorimeter. A large decrease in eluate and reagent flow rates greatly improves the handling of reagents and disposal of waste. Over 50 chromatographic peaks are obtained from 1 ml of urine. The limit of detection for most sugars is between 0.4 and 3.0 µg/ml.
Hydroxylysine Glycosides in Human Urine
Authors: Lou Marjorie F , Hamilton Paul B
Published: January 2020

Hydroxylysyl-galactosyl-glucose (HGG) and hydroxylysyl-galactose (HG) were isolated from normal human urine and shown to be identical with hydroxylysine glycosides (OHLG's) whose structure had been elucidated in other laboratories. We devised a procedure for separating the OHLG's from many other urinary constituents by preliminary fractionation on a column of Sephadex. The OHLG's in the fractions so obtained were then isolated, uncontaminated with other ninhydrin-positive components, in a single pass through an analytical cation-exchange column equipped for splitting the effluent stream. In addition, a procedure was devised for determining as little as 10-9 mol of the OHLG's in 100 µl of filtrate (corresponding to 83.3 µl, of urine) on standard ion-exchange chromatographic amino acid analyzers. In normal adult urine, 1.5, µmol of each glycoside was present per 100 mg of creatinine; the molar ratio of HHG to HG was about 1.1 to 1.2. Each was present in plasma in about 400- to 500-fold smaller concentration than in urine. After surgical fusion of the spine, excretion of OHLG's increased and the ratio of HGG to HG decreased, changes we interpreted as indicating a more rapid bone-collagen turnover consequent to surgical damage.
Screening Method for Detection of Drugs of Abuse in Human Urine
Authors: Weissman Norman , Lee Lowe Mei , Beattie John M , Demetriou James A
Published: January 2020

A simple, convenient method is described for the detection in human urine of three major classes of drugs of abuse: amphetamines, barbiturates, and alkaloids. The drugs are adsorbed from urine by a column of non-ionic resin (Amberlite XAD-2), eluted with methanol, and chromatographed on a thin-layer silica gel plate. The drugs are made visible and identified by a series of procedures involving exposure to ultraviolet radiation, heat treatment, sequential spraying with group-specific reagents, and measurement of Rf values. Detection limits for 5-ml urine specimens are: 0.4 µg per ml for amphetamines and barbiturates, and 0.8 g per ml for alkaloids. The test requires 6 h to perform. One technologist can process 50 specimens per day.
Aldolase Isoenzymes in Patients with Progressive Muscle Dystrophy and in Human Fetuses
Authors: Tzvetanova Elena
Published: January 2020

Aldolase isoenzymes were studied in serum and muscle tissue of normal individuals, 60 patients with different forms of progressive muscle dystrophy (PMD), and 50 patients with other types of neuromuscular diseases. The isoenzyme pattern has been investigated also in the muscle tissue of 30 human fetuses of six to 27 weeks. The isoenzymes were separated in agarose gel. In 40 sera from normals, two isoenzyme fractions were conspicuous, of which A4 was the stronger. In patients with PMD and acute polymyositis with marked hyperaldolasemia, the serum isoenzymogram was also changed. In all other patients with a normal serum aldolase activity, no changes were seen in the serum isoenzymogram. In 25 control muscle, biopsies one isoenzyme fraction, A4, was found. In patients with PMD and other neuromuscular diseases, changes in the muscle isoenzymogram were established, characterized by the appearance of one or two hybrid fractions (A3C + A2C2), and the muscle isoenzymogram resembled that of the fetal muscle. During embryonic development, human muscle tissue changes its isoenzyme pattern. During the earliest stages of development, because of the parallel synthesis of the A and C subunits, five isoenzyme fractions could be observed. In the stages that follow, the isoenzyme patterns showed a shift from C to A. By the end of the embryonic development A4 had become the prevalent form. The normal serum activity originates from muscle origin. Changes in the isoenzyme pattern of the muscle were paralleled by changes in the serum isoenzymogram of the patients with PMD. Significance of the data obtained and the role of regulator-genes is discussed.
Preservation of Urine with Sulfamic Acid in Soluble Packages
Authors: Peterson J I , Young D S
Published: January 2020

Sulfamic acid, in polyvinyl alcohol envelopes, makes a safe and convenient preservative for urine, 10 g/liter of urine being a satisfactory concentration. Of several chemical procedures for urine, this preservative altered the results only for steroids.
Influence of Certain Components of a Chemically Defined Diet on Urinary Excretion of Ultraviolet-Absorbing Compounds
Authors: Butts William C , Mrochek John E , Young Donald S
Published: January 2020

Young [Clin. Chem. 16, 681 (1970)] has recently reported tentative identifications for 12 compounds resolved by anion-exchange chromatography of urine from a subject on a vanilla-flavored synthetic diet. Relative excretion rates for the diet and control periods were also given for several of the chromatographic peaks. We are reporting positive identification of 26 of the resolved compounds and absolute excretion rates for 11 of these. The most significant differences between the diet and control chromatograms are the absence of 5-acetylamino-6-amino-3-methyluracil from the diet sample and the presence of a group of large peaks— including five peaks related to the vanilla flavoring and three peaks derived from 4-aminobenzoic acid—in the diet chromatogram. The 4-aminobenzoic acid derivatives were all acetylated; the chromatogram showed no evidence of un-acetylated products.
Diagnostic Value of Urinary Enzyme Determinations
Authors: Raab Wolfgang P
Published: January 2020

Information on physiology and pathology of urinary enzymatic activities is compiled. Attention is focused on the diagnostic applicability of urinary enzyme determinations. The data collected may stimulate the clinical chemist as well as the clinician to greater use of urinary enzymatic determinations. In many respects, systematic investigations still are lacking.
Albumin Quantitation by Dye Binding and Salt Fractionation Techniques
Authors: Miyada Don S , Baysinger Vernon , Notrica Solomon , Nakamura R M
Published: January 2020

Two dye-binding reagents, 2-(4'-hydroxybenzeneazo)benzoic acid (HABA) and bromcresol green (BCG), for the quantitation of serum albumin have been compared with the biuret colorimetric procedure after salt fractionation. The linear regression equations for the biuret-BCG and the biuret-HABA comparisons were y = 0.43 + 0.91x and y = -0.45 + 1.15x, respectively. Their corresponding correlation coefficients were 0.93 and 0.83, respectively. The effects of icterus, lipemia, and hemolysis on the dye-binding procedures were generally greater in the case of the HABA procedure. A comparison of results with BCG and HABA for 20 sera having A/G ratios of less than 1, indicates them to be equally reliable.
Fluorometric Determination of Primary and Secondary Amines in Blood and Urine after Thin-Layer Chromatography
Authors: Monforte Joseph , Bath Raymond J , Sunshine Irving
Published: January 2020

7-Chloro-4-nitrobenzo-2-oxa -1,3-diazole reacts with primary and secondary amines to produce highly fluorescent compounds. The resulting emission spectra for primary and secondary amines are similar; however, when the excitation spectra of these compounds are determined when the emission wavelength is kept at 520 nm, distinctly different results are obtained. Thin-layer chromatography of suitably concentrated aliquots of these solutions yield characteristic spots, the Rf values of which can be used to help identify the substances involved. This reaction was applied to the quantitative determination of amphetamine in biological extracts. If amphetamine is the only drug present it can be quantitated by fluorometry and confirmed by the thin-layer chromatographic procedure. If more than one drug is present, the fluorometric procedure is unsatisfactory for quantitative analysis. Thin-layer chromatography can be useful to identify qualitatively the drugs involved. Gas chromatography is the procedure of choice in these situations.
Use of 3-Methyl-2-Benzothiazolone Hydrazone in an Automated Colorimetric Method for Determination of Triglycerides in Plasma or Serum
Authors: Neeley W E , Goldman G E , Cupas C A
Published: January 2020

A new automated colorimetric method is described for the determination of serum or plasma triglycerides. The samples are extracted with 2-propanol containing activated alumina. An AutoAnalyzer Sampler II and Proportioning Pump II are used in combination with a Gilford Model 300 N spectrophotometer and Model 3091-A debubbler flow cell. Following on-line saponification, glycerol is oxidatively cleaved with sodium metaperiodate. The resulting formaldehyde is reacted with 3-methyl-2-benzothiazolone hydrazone (MBTH) under mild conditions to produce the corresponding azine. Further reaction of MBTH with the azine in the presence of an oxidizing agent results in the formation of a blue cationic adduct. Beer's law is obeyed, at 670 nm, to a triglyceride concentration of 400 mg/100 ml. Because of the high sensitivity of the MBTH reaction, short incubation periods, high sampling rates (60/h), and low flow rates can be used. The results correlate well with those obtained by the Kessler-Lederer method and by a totally enzymatic method.
Serum Propylthiouracil: Determination by a Direct Colorimetric Procedure
Authors: Ratliff Charles R , Gilliland Paul F , Hall Frank F
Published: January 2020

A direct colorimetric method is described for the determination of propylthiouracil in serum, which is based on reaction of the drug at pH 8.0 with 2,6-dichloroquinone-chloroimide to produce a colored chloroform-soluble compound. After isolation from the aqueous layer with phase-separating filter paper, the chloroform solution is read against a chloroform blank at 435 nm. Propylthiouracil added to drug-free serum serves as a control sample. The method obeys Beer's law up to a concentration of at least 10 mg/liter.
Rapid Method for Determining Ultrafiltrable Calcium in Serum
Authors: Halver Bent
Published: January 2020

A modification of a simple method for determining ultrafiltrable calcium in serum is presented. Because variations of pH influence the values for ultrafiltrable calcium, a correction for changes of pH is suggested in order to avoid anaerobic handling of the blood specimens. By this procedure the original method is made simpler, more rapid, and more accurate.
Automated Method for Determination of Serum 5'-Nucleotidase Activity
Authors: Bethune Victor G , Fleisher Martin , Schwartz Morton K
Published: January 2020

An automated method has been devised for determining 5'-nucleotidase activity in serum. A modified creatine phosphokinase cartridge (Technicon Instrument Corp., Tarrytown, N. Y.) is used to prepare a reaction mixture containing, per liter: barbital buffer (pH 7.5), 16.1 mmol; adenosine-5'-phosphate, 5.4 mmol; Mg2+, 20.2 mmol; phenyl phosphate, 7.8 mmol; adenosine deaminase, 0.78 mg; and sample, 0.21 ml/ml of reaction mixture. After incubation, the liberated ammonium ion is determined by use of the alkaline hypochlorite-phenol reaction. Nucleotidase activity as determined by the automated method correlated well with activities as determined manually by a Ni2+ inhibition—phosphate analysis procedure. Respective values obtained by the manual and by this procedure were: for sera with activities within the normal range, 7.9 ± 3.2 and 8.2 ± 3.3 U/liter; for activities between 16 and 50 U/liter, 26.3 ± 9.3 and 26.5 ± 8.8 U/liter; and for serum with activities greater than 50 U/liter, 79.1 ± 42.5 and 78.7 ± 41.3 U/liter.
Aspartate Aminotransferase ("SGOT") Assay in Serum, with Use of the AutoAnalyzer II 340 Colorimeter in a Conventional AutoAnalyzer I System, Including Dialysis
Authors: Levy Arthur L , Konig-Levy Susanna
Published: January 2020

For assay of serum aspartate aminotransferase activity the AutoAnalyzer II single-channel 340-nm colorimeter has been substituted in the AutoAnalyzer I system. The larger dialyzer requires proper balance between the liquid streams entering and leaving the flow cell, and between air-bubble size and total flow rate. For precise air metering, an air-bar has been improvised. Analysis rate is 60 per hour, the samplewash ratio is 1:2. Through-put time is 15 min. The reaction is linear to 200 Karmen units without serum blanks. Sera were analyzed by our hybrid system, by an automated Transac procedure, by Henry’s manual 340 nm kinetic method, and by the 340-nm SMA-12 method. The results were not significantly different. Within-run precision at three concentrations is 2.13.8% (coefficient of variation). Day-to-day precision CV is 4.3%. Interaction is 2 to 4%.
Evaluation for Four Reagent Kits and Two Flame Photometers Used to Determine Sodium and Potassium in Serum
Authors: Kim Edward K , Waddell Leslie D , Logan James E
Published: January 2020

The Stanbio and Medi-Chem sodium and potassium kits were evaluated and the results compared with those obtained with the Coleman Jr. Model 21, NIL 4-7000, and Technicon flame photometers. Day-to-day reproducibility studies and data based on comparative studies with sera from patients revealed that the Stanbio and Medi-Chem sodium kits and the Medi-Chem potassium kit give diagnostically unsatisfactory results. Results with the Stanbio potassium kit were reproducible, but further improvement is required, as indicated by nonspecificity in the analyses of patient sera. Instability of the Coleman Jr. flame photometer made it difficult to obtain acceptable data in these tests, particularly for sodium, while the NIL flame photometer had good precision and accuracy.
Blood Carboxyhemoglobin: Results with Conventional Standards Compared with Those with a Submicroliter Reference of Gaseous CO
Authors: Sundström Gunnar
Published: January 2020

The reference standard for the determination of CO in blood usually consists of whole blood or hemoglobin (Hb) solutions equilibrated with 100% CO. A new, simple method for injecting very small gas volumes with high accuracy and reproducibility makes possible a closer study of the CO extraction process from blood (e.g., into neutral ferricyanide). The present method for CO analysis is based on a "gas chromatographic" system with CO detection as methane by flame ionization. In preparing blood COHb standards, notice must be taken of physically dissolved CO and "COrefractory" hemoglobin (e.g., methemoglobin). Solutions to this problem are suggested. The validity of the factor 1.39 (ml) for maximal CO binding capacity of 1 g of Hb is discussed in comparison with the experimentally measured recovery, about 97% for a fully saturated Hb solution.
Automated Direct Method for Measurement of Serum Cholesterol, with Use of Primary Standards and a Stable Reagent
Authors: Holub William R , Galli Frank A
Published: January 2020

A manual direct determination of serum cholesterol [Clin. Chem. 16, 980 (1970)] has been adapted for automation. Optimal reaction temperature and reaction time were determined. The aqueous standard used is equivalent to NBS Standard Reference Material No. 911. Commercial control sera and 60 randomly chosen specimens were used to check accuracy and precision against the method of Abell et al. [J. Biol. Chem. 195, 357 (1952)]. The correlation coefficient was 0.980. When these results were compared with those obtained with the SMA 12/60, the latter method had significant differences when there was interference from hemoglobin, bilirubin, gamma globulin, or gross lipemia. For a pooled serum, the inter-run relative standard deviation (coefficient of variation) was ±2.7%. Advantages over other automated direct methods for serum cholesterol include: use of primary standards, the stable and less noxious reagent, simplicity of the manifold, longer life of the reagent manifold tubing, and the decrease in photometric interferences.
Test for Mucopolysaccharidoses: Simple Method for Quantitative Estimation of Urinary Glycosaminoglycans
Authors: Calatroni Alberto
Published: January 2020

A simple method is described for measurement of urinary glycosaminoglycans (GAG) in normal and pathological urine: a fixed fraction of the 24-h urine is passed over a small plug of ECTEOLA-modified cellulose and the GAG are eluted with a few milliliters of NaCl solution (3 mol/liter) and measured as hexuronic acid. Because results are compared for equal aliquots of complete 24-h urines, GAG are quickly detected, thus providing means for a chemical diagnosis of mucopolysaccharidosis. The procedure requires less than 1 h, and several tests may be conveniently run simultaneously. When urine specimens collected from normal children or children affected by mucopolysaccharidosis were analyzed, the results obtained with the proposed procedure agree well with those of more elaborate, widely accepted methods.
"Glycerate Dehydrogenase" Activity in Acute Myocardial Infarction and Myocardial Ischemia
Authors: McQueen M J , Garland I W C , Morgan H G
Published: January 2020

Hydroxypyruvate has been shown to be an alternative substrate for lactate dehydrogenase. The clinical value of this "glycerate dehydrogenase" has been investigated on 60 patients admitted to the hospital with a provisional diagnosis of myocardial infarction. For comparison, lactate dehydrogenase, α-hydroxybutyric dehydrogenase, creatine kinase, aspartate transaminase, and alanine transaminase were also assayed at 37°C. Normal ranges and methods of assay are given for each enzyme. Glycerate dehydrogenase has greater activity than any other enzyme and parallels lactate dehydrogenase and α-hydroxybutyric dehydrogenase in its time of peak activity and duration of increased activity. Clinical and biochemical evidence is provided to show that α-hydroxybutyric dehydrogenase is not specific for the cardiac isoenzymes. Of the enzymes studied, creatine kinase activity increases most quickly after myocardial infarction, and an exclusive role for its use in coronary care units is also suggested.
Implication of Creatinine and Gut Flora in the Uremic Syndrome: Induction of "Creatininase" in Colon Contents of the Rat by Dietary Creatinine
Authors: Jones James D , Burnett Philip C
Published: January 2020

"Creatininase" activity was induced in the colon flora of rats by feeding creatinine. Sarcosine and methylamine were tentatively identified as the major products of the enzymic action. A third (unidentified) compound was observed. These compounds and methylguanidine were labeled in the urine of rats given 14CH3-creatinine orally. The results suggest that creatinine should not be considered biologically inert in animals, especially in those with decreased renal function.
Rapid Extraction of Triglycerides from Human Adipose Tissue with Petroleum Ether
Authors: Newman H A I , Gordon Elizabeth A , Heggen Darrol W , Keller Martin D
Published: January 2020

A rapid method has been developed for extracting neutral lipid from small samples of human adipose tissue, with a petroleum ether ("Skellysolve B") as the extracting solvent. It is coupled with a simple method of transesterification, to convert the purified triglycerides to fatty acid methyl esters. Virtually no phospholipid is extracted by the petroleum ether. Analysis of the extracted lipid by gas—liquid chromatography yielded fatty acid distributions comparable to those obtained by chloroform—methanol extraction.
Multiple Myeloma Presenting as Adult Fanconi Syndrome
Authors: Headley Robert N , King J Stanton , Cooper M Robert , Felts John H
Published: January 2020

This report describes the clinical course of a 55-year-old woman with multiple myeloma presenting as adult Fanconi syndrome.
Quality Control of an Automated Differential Isoenzyme Assay of Alkaline Phosphatase, with Use of L-Phenylalanine Inhibition
Authors: Cantor Fred , Green Sidney , Stolbach Leo L , Fishman William H
Published: January 2020

A quality-control program, in which a heat-stable human alkaline phosphatase preparation is used to monitor the performance of an automated alkaline phosphatase method, was observed for a year. In the method phenyl phosphate is used as substrate, L-phenylalanine as an intestinal isoenzyme inhibitor, and a phenol standard curve to monitor chromogen formation. Mean total alkaline phosphatase activity was 14.0 ± 0.9 King-Armstrong units (CV, 6.4%), and mean inhibition by L-phenylalanine was 78.2 ± 1.1% (CV, 1.4%). These data compared closely with the data obtained in a collaborating laboratory during the same one-year period.
Elimination of Dextran Interference in Serum Protein Determinations
Authors: Moore John J , Sax Sylvan M
Published: January 2020

Ethylene glycol, 120 ml per liter of biuret reagent, eliminates the falsely high values for serum proteins caused by as much as 2 g of either "Dextran 40" or "Dextran 75" per deciliter of serum.
Semiquantitation of Leucine, Isoleucine, and Valine by Thin-Layer Chromatography in Management of Maple-Syrup Urine Disease
Authors: Allen Richard J , Frey H Jeane , Fleming LaDona M , Owings Clyde L
Published: January 2020

A few microliters of serum suffice to estimate the leucine, isoleucine, and valine present. The three branched-chain amino acids are separated by unidirectional thin-layer chromatography, and estimated by visual comparison with co-chromatographed individual standards in graduated concentrations. The method is especially applicable to the frequent monitoring of serum branchedchain amino acids needed in treating patients with maple-syrup urine disease, and may also be used for rapid diagnosis of the disease in suspected infants.
Spectrophotometric Micromethod for Measuring Cholinesterase Activity in Serum or Plasma
Authors: Uete Tetsuo , Miyamato Yoko , Ohnishi Mieko , Shimano Noriko
Published: January 2020

A simple ultraviolet method has been developed for determining serum or plasma cholinesterase activity. The cholinesterase acts on acetyl- or butyrylthiocholine to release thiocholine, which reacts with 2,2'- or 4,4'-dithiodipyridine, showing absorbance at 324 or 343 nm, respectively. The activity can be measured kinetically and also after incubation for 3 to 5 min at 20° to 37°C. A volume of 10 µl of serum or plasma is sufficient for the determination. This method is well suited for clinical investigation as well as experimental studies.
Symptomatic Porphyria in a Case of Felty’s Syndrome. I. Clinical and Routine Biochemical Studies
Authors: Eales L , Sears W G , King K B , Levey M J , Rimington C
Published: January 2020

This report deals with the case of a 64-year-old white woman with long-standing Felty’s syndrome who developed symptomatic porphyria during the last three years of her life. Clinical and biochemical findings were typical of those for symptomatic porphyria, except for lack of exposure to alcohol and the absence of hepatic siderosis. The course of this patient was dominated by repeated infections, which were undoubtedly related to the persistent neutropenia and the multiple portals of infection provided by the porphyric skin lesions. Splenectomy and steroid therapy led to a brief increase in the leukocyte count. Despite the apparent effectiveness of methenolone therapy in returning the leukocyte count toward normal, she died as a result of a severe pulmonary infection, and at autopsy a lung abscess was demonstrated. Daily porphyrin excretion progressively declined during the two periods of hospitalization, but cutaneous porphyric lesions continued to appear, although with less intensity. The large amount of porphyrin excreted in the early phases provided abundant material for the intensive investigations reported in Part II of this report.
Hydrochlorothiazide Interference with Urinary Estriol Determination
Authors: Rosenthal Arthur F , Tomson Marie R
Published: January 2020

The commonly used diuretic, hydrochlorothiazide, interferes with the determination of urinary estriol, by destroying the latter during acid hydrolysis. Urine specimens from pregnant patients taking this diuretic may therefore show falsely low estriol values.
Direct-Contact (Membraneless) Hemoperfusion through Oils
Authors: Evenson M A , de Vos D
Published: January 2020

Oil-hemoperfusion is a highly promising procedure, as indicated by in vitro feasibility studies with human blood and in vivo experiments with rhesus monkeys. Direct liquid—liquid extraction is used to remove toxic or unwanted substances from whole blood. By choosing the proper oil or modification of an oleaginous liquid, cholesterol, total bilirubin, and lipid-soluble drugs such as glutethimide can be selectively removed or adjusted to the desired concentration with a single liquid—liquid extraction. Damage or loss of cellular components such as erythrocytes, leukocytes, and platelets is immeasurably small or nonexistent. Undesirable extraction of other vital biological substances and (or) back extraction of substances from the oil into the blood is so small that side effects or aftereffects of in vivo oil-hemoperfusion studies were considerably less than anticipated.