bluuebunny/crossref_metadata_2025 huggingface dataset:
Usefulness of Serum Lipase, Esterase, and Amylase Estimation in the Diagnosis of Pancreatitis—a Comparison
Authors: Song Harriet , Tietz Norbert W , Tan C
Published: January 2020

Sera of 19 individuals with clinically established pancreatitis were analyzed for lipase activity on emulsion-type and aqueous substrates. Serum amylase concentrations were compared. Results obtained on the first and subsequent days of hospitalization clearly indicated that methods for lipase determination in which an emulsion-type substrate is used are of the greatest aid in diagnosing pancreatitis (90 to 92% of patients with pancreatitis had supranormal results). Amylase determinations were nearly as useful as an index (78% correlation), but "lipase" values obtained with methods in which aqueous substrates are used had limited clinical usefulness (29 and 32% correlation). Serum lipase elevations in cases of pancreatitis were generally greater than amylase elevations, with some exceptions. Serum lipase should be determined with a method in which emulsion-type substrates are used. Lipase and amylase values supplement one another.
In Vitro Formation of Ammonia in Blood of Dog and Man
Authors: Prytz Bo , Grossi Carlo E , Rousselot Louis M
Published: January 2020

A significant (p <0.001) difference was found in the rate of ammonia formation and the amount formed in heparinized dog and human blood at 4°C. The initial ammonia concentration and the increase in ammonia formation with time were correlated for human blood. This in vitro ammonia formation was not prevented by certain enzyme inhibitors, but it continued after cells and plasma were exhaustively dialyzed against water or saline, suggesting that it originates from enzyme action.
Free-Electrophoretic Behavior of Urea-Insulin Reaction Products
Authors: Bischoff Fritz , Bakhtiar Abolfath Khan
Published: January 2020

Five reaction products, previously isolated from an aqueous mixture of insulin and concentrated urea that had been subjected to various conditions of time and temperature, were examined by moving-boundary electrophoresis. Insulin OU and insulin IU separated into major and minor peaks with mobilities identical to those observed by Timasheff et al. (and confirmed by us) for intact crystalline insulin. Insulin IIU showed a major peak (80%) with a mobility of -7.6 x 10-5 cm/s/V/cm. Insulin IIIU showed a major peak with a mobility of -9.2 x 10-5 cm/s/V/cm. On the basis of change in electron charge and the fact that guanidine does not produce the effects of urea, it is postulated that the delayed-acting urea insulin (IIU) is formed by native insulin reacting with the isocyanate ion in urea solution.
A Method for Determination of Cystine in Urine
Authors: Haux Peter , Natelson Samuel
Published: January 2020

A procedure is described for the assay of cystine in urine. Cystine is ad-sorbed on a column of Dowex-50 resin at pH 2, which is then washed with water and eluted with sodium acetate solution. Color is developed with 1,2-naphthoquinone-4-sulfonate. Homocystine does not interfere in the reaction. Routine reproducibility in the laboratory was ±10.3% (2 SD) for 24 normal urines, which contained 8 to 86 mg cystine per 24 h (those values falling within 2 SD). Mean recovery was 94.5%. In two cases in which the results were compared with those obtained with the amino acid analyzer, the method was indicated to be valid for screening urine to detect cystinuria
A Semiautomated Nonincineration Technique for Determining Serum Thyroxine
Authors: Kessler Gerald , Pileggi Vincent J
Published: January 2020

Thyroxine and triiodothyronine are separated from other serum iodine-con-taining constituents by column chromatography. The iodine compounds of a serum sample adjusted from pH 10 to 11 are absorbed on an anion-ex-change resin, which is washed to remove serum proteins, mono- and diio-dotyrosines, and some organic iodine compounds of exogenous origin. Thyroxine and triiodothyronine are quantitatively eluted with 50% acetic acid and then measured by the Ce+4-arsenite reaction by use of the Auto-Analyzer. The eluates are automatically added to a reaction mixture contain-ing sulfuric acid and bromate-bromide reagent. The resulting bromine inac-tivates unidentified inhibitors and enhances the catalytic activity of thyrox-ine, thus eliminating the necessity for incineration or wet-digestion. Arsen-ous acid and Ce+4 reagents are then added to initiate the iodide-catalyzed Ce+4 arsenite reaction. On passing through two 13-m glass coils at 60°C, Ce+4 in the reaction mixture is reduced to colorless Ce+3 by iodine released from the thyroxine molecule, and measured colorimetrically at 400 nm. The analytical rate is 50 specimens per hour. Recovery data utilizing is pre-sented for the chromatography steps. The total system recovery for T4 averaged 98% (range, 85 to 112%) with a precision of ±8.5%(±2 CV). Interfer-ence by 19 organic contrast media was evaluated
Faster Extraction of Phenylbutazone from Blood and Plasma
Authors: Stevens H M
Published: January 2020

A faster method is described for extracting phenyl-butazone from blood, plasma, and liver.
Nomogram for Calculation of Creatinine Clearance
Authors: Gindler E Melvin
Published: January 2020

An alignment chart nomogram, actually a combination of three nomograms, is presented for use in the calculation of creatinine clearance over a broad range of serum and urine concentrations. Urine collection times may range from 1.5 to 30 h. Examples are given of the use of the nomogram. The significance of the creatinine clearance equation is briefly discussed.
Reaction of Sodium Aminohippurate with Folin’s Reagent
Authors: Rahill W J , Wilson A C , Stubbins M
Published: January 2020

In the Lowry method for protein, 1 mg of p-aminohippurate gives a color equivalent to 0.6 mg of protein. This method should not be used on fluids from patients receiving p-aminohippurate.
Emergency Gas—Liquid Chromatographic Determination of Barbiturates and Glutethimide in Serum
Authors: Sine H E , McKenna M J , Rejent T A , Murray M H
Published: January 2020

A method is presented for the rapid gas chromatographic determination of barbiturates and glutethimide in serum, suitable for use in clinical emergencies. The sample is prepared for gas chromatography by acidification and a single extraction with chloroform. From 70 to 100% of the various barbiturates and glutethimide are analytically recovered, with a coefficient of variation of 8 to 10% for the method. During a 10-month clinical evaluation (87 requested determinations), 34 analyses (39% of the samples submitted) were positive for barbiturates, glutethimide, or both.
Atomic Absorption Spectrophotometry of Rubidium in Biological Fluids
Authors: Sutter E , Platman S R , Fieve R R
Published: January 2020

The atomic absorption spectrophotometric method for measurement of rubidium in serum, plasma, whole blood, and urine was evaluated, and the effects of interfering ions were studied. Absorbance was most enhanced by potassium and sodium; calcium, bicarbonate, and chloride at the concentrations found in serum did not affect rubidium absorption. Naturally occurring rubidium concentrations in serum, plasma, whole blood, and urine are 3, 4, 70, and 18 µEq/liter, respectively, much lower than expected therapeutic concentrations. Methods for preparing standards, optimum instrument settings, and special treatment of samples were established with specimens from monkeys treated with rubidium. These procedures are applicable to human bloods from patients receiving rubidium therapy when such therapy is begun for treatment of affective disorders.
The Microscope, Spectra, and Automated Analysis
Authors: West Seymour S
Published: January 2020

Fluorescence spectroscopy (FS) and optical rotatory dispersion (ORD) have been added to the capabilities of the microscope. With them, as with conventional spectroscopy, a single component can be detected, even when in a mixture. This ability is enhanced by use of certain fluorescent dyes or "molecular probes" such as acridine orange (AO). Molecular complexes between dye and substrate may have characteristic physical-optical and physical-chemical properties. The microscope used for FS and ORD studies can produce fluorescence- and ORD-spectra from selected portions of unfixed cells and tissues and from extremely small amorphous samples. Characteristic spectra can be obtained from as little as 10-17 moles of sample. It is possible to obtain cytochemical data that closely resembles, both spectroscopically and numerically, data obtained from solution studies on in vitro model systems, and consequently it is possible to predict quantitatively the results of interaction of cells with dye. Previous work in cytochemistry cannot produce such correlations, nor is it useful for quantitative prediction. Data so obtained with the microscope and corrected for instrumental parameters, can be used in design of automated analytical systems capable of detecting and quantitating particular biopolymers even in an intact unfixed cell. When a particular biopolymer can serve (qualitatively or quantitatively) to characterize a cell type, automated identification, counting, and separation can readily be devised from predetermined optical properties. The fluorescence and ORD spectra of the microscopic samples determine the complexity of the automated systems. Not only can relatively simple instruments sometimes serve, but automation of an analysis that cannot be definitive can be avoided.
Preliminary Results from High-Resolution Analyses of Ultraviolet-Absorbing and Carbohydrate Constituents in Several Pathologic Body Fluids
Authors: Jolley Robert L , Scott Charles D
Published: January 2020

Human urine, blood serum, cerebrospinal fluid, and amniotic fluid have been analyzed by high-resolution chromatographic systems under development at the Oak Ridge National Laboratory. These systems, or analyzers, consist of heated, high-pressure anion-exchange columns for chromatographic separation of the constituents and continuous-flow ultraviolet spectrophotometry or phenol-sulfuric acid colorimetry for detection of the separated ultraviolet-absorbing or carbohydrate components. Quantification of the resulting chromatograms has revealed significant differences in the concentrations of body-fluid constituents for the normal state and for various pathologic states such as hereditary nephritis, Lesch-Nyhan syndrome, gout, alkaptonuria, and maple syrup urine disease. Some changes in urinary chromatographic patterns resulting from nicotinic acid and allopurinol therapies have also been detected.
Serum Organic Acids in Sheep Exposed to Neutron—Gamma Irradiation, Air Blast, or Both
Authors: Henderson Thomas R , Jones Robert K
Published: January 2020

Organic acids were measured in serum from sheep that had been exposed to neutron—gamma irradiation, air blast, or both to determine which concentrations change after experimental injury. Samples were directly analyzed by partition chromatography and indicator titration. The semiautomated instrument efficiently separates mixtures of monocarboxylic acids. Monocarboxylic acids in serum seem to be sensitive indicators of biological injury. Survey experiments showed that lactate and propionate accumulate in sheep serum after severe air-blast injury, but only propionate after irradiation. Propionate-loading studies suggested that the utilization of injected propionate is impaired, to various degrees, in fasting, irradiation, and air blast. However, presumptive impairment of propionate utilization occurred earlier in sheep exposed to irradiation and blast than in only irradiated animals, and earlier in irradiated animals than in fasting controls. Air blast exposure resulted in effects of only borderline significance.
Effect of Dietary Purine Restriction, Allupurinol, and Oxipurinol on Urinary Excretion of Ultraviolet-Absorbing Compounds
Authors: Kelley William N , Wyngaarden James B
Published: January 2020

We demonstrate that purine restriction is associated with a decreased excretion of a number of uv-absorbing compounds—including uric acid, hypoxanthine, xanthine, adenine, pseudouridine, and 5-acetylamino-6-amino-3-methyluracil—indicating that these compounds originate, at least partly, exogenously. Administration of allopurinol and oxipurinol is associated with a decreased excretion of uric acid and an increased excretion of hypoxanthine and xanthine, as well as the excretion of the previously identified products of allopurinol and oxipurinol metabolism. Moreover, these drugs further decrease excretion of 5-acetylamino-6-amino-3-methyluracil, increase uracil excretion slightly, and strikingly increase orotic acid and orotidine excretion. No change in pseudouridine excretion was observed. The ultraviolet-analyzer is a valuable tool for detecting qualitative changes in the excretion of ultraviolet-absorbing compounds in the urine; with it, identified peaks can be semiquantitated.
Serum Content of Macroglobulins (19S Fraction) and Its Variation with Age when Determined by Thin-Layer Gel-Filtration
Authors: de Goldman Lleni Pach , Ballivian Liliana , Melgar Ernesto
Published: January 2020

Serum proteins were fractionated by thin-layer gel-filtration on Sephadex G-200, and the content of macroglobulins (19S fraction) was determined in 137 samples from apparently healthy subjects of different ages. The relationship between amount of 19S fraction relative to total protein was found to vary widely with age. This variation has to be considered when the method is used for clinical purposes.
Pediatric Xylose Absorption Test: Measurements in Blood Preferable to Measurements in Urine
Authors: Hawkins K I
Published: January 2020

Data from 129 pediatric patients given oral xylose tolerance tests were reviewed and statistically analyzed to determine if blood concentrations are a more acceptable diagnostic tool than urinary excretion. After oral administration of D-(+)-xylose, blood xylose concentrations were measured at 0.5, 1, 2, 3, and 4 h, and a 5-h urine sample was analyzed. Urinary xylose excretion was more variable than blood concentration. The best criterion of celiac disease through blood sampling is a failure of blood xylose to increase during the first hour of the test. An age difference was observed but appears to be critical only if the patient is less than six months old: the lower limits of normal as determined at 0.5, 1, and 2 h are 10, 15, and 15 mg/100 ml, respectively, for patients less than six months old; and 15, 20, and 20 mg/100 ml, respectively, for older patients.
Quantitation of Sputum Protein by Use of the Biuret Reaction
Authors: Fields Joyce P , Chodosh Sanford
Published: January 2020

A simple, accurate method is described for quantitatively determining the protein content of sputum by use of the biuret reaction. Fifteen mechanically homogenized specimens were examined with the biuret reagent described by Rosenthal and Cundiff, and the results compared with those obtained by the microKjeldahl technique. Over a range of 542 to 1917 mg of protein per 100 ml, the techniques correlated significantly. Difficulties with deproteinization of the sputum before nonprotein nitrogen was determined were overcome by the use of zinc sulfate and pH adjustment. The proposed method is fast and reproducible.
Automated Hydrolysis of Total Estrogens in Urine from Pregnant Women
Authors: Muir G G , Ryan M
Published: January 2020

This method for the hydrolysis of estrogens completes the automated analysis of estrogens in pregnancy urine described by Muir, Ua Conaill, and Ryan [Steroids 13, 719 (1969)]. Pregnancy urines can be processed from the sampling of urine to the recording of fluorescence intensity in 30 min, at a rate of 20 samples per hour. The presence of glucose does not decrease the apparent hydrolysis products.
Manual Procedure for Direct Microassay of Serum Glucose by Use of o-Toluidine, and Its Adaptation to the SMA 12/60 AutoAnalyzer
Authors: Webster W W , Stinson S F , Wong W H
Published: January 2020

A direct o-toluidine method for serum glucose is described as an alternative to the usual Cu—neocuproine method used with the Technicon SMA 12/60 AutoAnalyzer. Routine operation of the machine is simplified: the number of reagents and manifold lines is decreased and the dialyzer and pre-heating bath are eliminated. Deterioration of manifold tubing is minimized, while maintaining optimal machine sensitivity by adding borate and water to the reagent. Serum glucose was measured by the automated o-toluidine and Cu—neocuproine methods with similar, highly correlated results. Thus, the "normal limits" are unchanged and the same recorder graph paper may be used. A direct manual micro-method is also described, in which an anhydrous o-toluidine reagent is used. Results of manual and automated methods agree satisfactorily.
Murayama Test for Hemoglobin S: Simplification in Technique
Authors: Nichols Bruce M , Nalbandian Robert M , Henry Raymond L , Wolf Paul L , Camp Frank R
Published: January 2020

An improved technique is reported for the Murayama test, which is a simple and specific test for S hemoglobin [Clin. Chem. 16, 945 (1970)]: moisturized N2 is used optimally and several steps are eliminated in the part of the test in which concentrated hemolysates are prepared by use of a dense sucrose solution. Each test, which took 1 h, can now be done in 20 min, with equal reliability and accuracy.
Simplified Turbidimetric Assay for Lipase Activity
Authors: Shihabi Zakariya K , Bishop Charles
Published: January 2020

Serum lipase is determined by following turbidity changes during two 1-min intervals after adding serum to an olive oil emulsion containing desoxycholate. The olive oil emulsion is simply prepared and is stable for a month under refrigeration. Our observations confirm the findings of other investigators that increases in serum lipase activity are more accentuated than increases in serum amylase activity during pancreatitis. With the present fast and convenient method, serum lipase appears to be a better test for pancreatitis than is serum amylase.
Metastatic Adrenal Cortical Carcinoma: Biochemical Changes Accompanying Clinical Regression During Therapy with o,p'-DDD
Authors: Helson Lawrence , Wollner Norma , Murphy M Lois , Schwartz Morton K
Published: January 2020

A 7-year-old girl with a six-month history of increasing virilism, growth, and acne excreted supranormal amounts of urinary 17-ketosteroids (87.6 mg/24 h). ACTH stimulation and dexamethasone suppression studies indicated adrenal tumor. A large left adrenal carcinoma was removed. Metastases were not observed. Postoperatively, 24-h urinary ketosteroids remained supranormal (16 mg). Sudden fever, cough, and hemoptysis precipitated hospitalization 42 months later. Bilateral lung metastases, a mass in the right upper quadrant, virilism, advanced bone age, and supranormal 24-h urinary ketosteroids (166 mg) and hydroxysteroids (16 mg) were found. The patient received 240 g of o,p'-dichlorodiphenyl-dichloroethane (o,p'-DDD), whereupon the abdominal mass and lung lesions regressed and 24-h urinary ketosteroids and hydroxysteroids decreased. Since this treatment (which ended April, 1968) the patient has been maintained at home on 7.5 g o,p'-DDD/day and replacement therapy with 9-α-fluorohydrocortisone and cortisone acetate. Almost all signs and symptoms have disappeared and urinary steroids are normal.
Electrophoretic Separation of Serum Lipoproteins in Polyacrylamide Gel
Authors: Frings Christopher S , Foster Lowell B , Cohen Patricia S
Published: January 2020

A method is described for electrophoresing lipoproteins in polyacrylamide gels, in which separations depend both on electrophoretic mobility and molecular size. The sample is prestained with Sudan Black B in a sample gel and then resolved by electrophoresis in a discontinuous pH system consisting of a sample gel, concentrating gel, and separating gel. This method was compared with the paper electrophoretic method of Lees and Hatch [J. Lab. Clin. Med. 61, 518(1963)] and was found to be equally useful in phenotyping lipoproteinemias, with two distinct improvements over paper electrophoretic methods: lipoproteins are more quickly and discretely separated.
Use of a New Reducing Agent, Metamizol, in Determining Inorganic Phosphorus in Blood and Urine
Authors: Guirgis Fayez K , Habib Yehia A
Published: January 2020

We introduce a new reducing agent, metamizol, for determining inorganic phosphorus colorimetrically in a protein-free filtrate of serum or plasma or in a diluted urine specimen. A 1 g/100 ml solution of metamizol, 0.2 ml, is used with acid-molybdate reagent. The metamizol solution is stable at 4°C for as long as 3.5 months, and can replace the reducing agents used in the various reference procedures discussed. The results agree well with those obtained by standard procedures.
Direct Blood-Injection Method for Gas Chromatographic Determination of Alcohols and Other Volatile Compounds
Authors: Jain Naresh C
Published: January 2020

An extremely simple, rapid method is described for simultaneously determining methanol, ethanol, acetone, isopropanol, and low-boiling hydrocarbons associated with glue sniffing. Less than 1 µl of blood, mixed with an internal standard, is injected directly into a low-cost gas chromatograph equipped with a flame-ionization detector. No extraction, distillation, and (or) sample preparation is required, and the method is sensitive to less than 10 µg of alcohol per ml.
Simultaneous Direct Estimation by Atomic Absorption Spectrophotometry of Copper and Zinc in Serum, Urine, and Cerebrospinal Fluid
Authors: Meret S , Henkin R I
Published: January 2020

A method is described for simultaneously estimating copper and zinc in serum, urine, and cerebrospinal fluid by atomic absorption spectrophotometry. Standards are prepared in 150 millimolar NaCl solution, and subsequently standards and samples are diluted with n-butanol:water (6:94, by vol). Both ions may be simultaneously determined in as little as 0.5 ml. The procedure is simple, quick, reliable and reproducible.
Biological and Analytic Components of Variation in Long-Term Studies of Serum Constituents in Normal Subjects
Authors: Young D S , Harris Eugene K , Cotlove Ernest
Published: January 2020

Blood was sampled from nine healthy subjects weekly for 10 weeks, under controlled conditions. Eighteen serum constituents were measured in duplicate in each sample on a single occasion. In this way analytic variation was minimized. Considerable variations in mean values and standard deviations of results were observed among the subjects. Physiological control of serum calcium and magnesium concentrations appeared to be more precise than duplicate determinations in the laboratory. Compared with a previous study from this laboratory, significantly different estimates of personal variation were noted for sodium, chloride, urea nitrogen, cholesterol, and LDH in a group matched by age, race, and sex. At the same time, the present study group, homogenous with respect to these demographic factors (and also occupation) showed as great a diversity in the mean concentrations of most constituents as was seen earlier in a larger, more heterogenous group of normal individuals. These findings indicate that certain blood parameters depend more on personal characteristics than on broad demographic factors.
Separation of Proteins in Concentrated Cerebrospinal Fluid by Two-Dimensional Electrophoresis in Acrylamide Gel
Authors: Wright G L
Published: January 2020

Two-dimensional electrophoresis in acrylamide was used to separate the proteins in concentrated cerebrospinal fluid (CSF). More than 60 such components could be detected, twice as many as separated by conventional polyacrylamide techniques. Many of the proteins were common to CSF and serum. The high resolution attainable with this procedure may make it useful in detecting specific CSF alterations associated with neurologic diseases.
Blood Glucose Determination without Deproteinization, with Use of o-Toluidine in Dilute Acetic Acid
Authors: Ceriotti Giovanni
Published: January 2020

A method is described for determining glucose in 25 µl of plasma. o-Toluidine is used in weak acetic acid solution. Addition of the emulsifier "Cremophor" obviates the need for deproteinization. The reaction is complete after 15 min at 100°C, and the color is stable for longer than 24 h. The blank is almost colorless. The reagent is stable, colorless, not viscous, and convenient to handle.
Colorimetric Measurement of Serum Bromide with a Bromate-Rosaniline Method
Authors: Goodwin Jesse F
Published: January 2020

A procedure is presented for measuring bromide in serum filtrates, after protein has been precipitated with a HCl—tungstate reagent. The bromide in the filtrate is oxidized to bromate with hypochlorite. The resulting bromate reacts with added bromide to release bromine. Bromine reacts with rosaniline to form bromorosaniline, which is measured colorimetrically. The method is specific, sensitive, and reproducible. Bilirubin and hemoglobin do not interfere appreciably with the procedure, and iodine interference is negligible if less than 80 mg is present per 100 ml. Various factors affecting the sensitivity of the method have been studied. Preliminary data on the estimation of bromide in urine are also presented.
A Superior Counting Solution for Water-Soluble Tritiated Compounds
Authors: Carter G W , Dyke K Van
Published: January 2020

We describe a simple liquid-scintillation solution for use with water-soluble tritiated compounds that is superior to other such systems. Its advantages include: (1) a refrigerated-type liquid scintillation spectrometer is not needed because the solution has extremely good thermal stability from 22° to 75°C; (2) counting efficiencies are high from pH 1-12, therefore eliminating neutralization; (3) a sample is stable for at least one week, with a 7% variation in counting after three weeks (a comparison with counting in Bray's and Triton X-100 solutions is included); (4) there is no detectable phosphorescence or chemiluminescence; (5) toluene need not be analytical grade; (6) for more than 10,000 samples, efficiency has deviated less than 5%; (7) there is no odor (except for the toluene) as with naphthalene "cocktails" (Bray’s solution); (8) cost of the system compares favorably with that for other counting systems; (9) plastic vials can be used (40% less costly than glass) and are easily cleaned because of the detergent qualities of the cocktail. The only obvious disadvantage of the system is that high salt concentrations (>5 g of NaCl per 100 ml) cause a marked decrease in efficiency of aqueous radioactivity, and somewhat erratic counting for the toluene internal standard. However, additional solubilizer will sometimes correct this problem.
Automated Reaction-Rate Method for Determination of Serum Creatinine with the CentrifiChem
Authors: Fabiny Diane L , Ertingshausen Gerhard
Published: January 2020

An automated kinetic method to determine creatinine in serum with the Jaffé reaction is described. The method does not require deproteinization or adsorption of creatinine on Fuller's earth or ion-exchange resin. A maximum of 29 serum samples, standards, and control sera can be assayed in less than 1.5 min. Interferences by most of the known Jaffé-positive serum constituents were studied and minimized by optimal selection of the time interval during which the reaction rate was measured. Results of precision studies and correlation with a manual method requiring adsorption of creatinine on ion-exchange resin are reported. Spectroscopic data suggest that the product of reaction between picrate and creatinine is a 1:1 adduct of the two starting molecules.
High-Resolution Chromatography of Complex Organic Mixtures
Authors: Stevenson Robert L , Burtis Carl A
Published: January 2020

The high-resolution uv analyzer has been used to investigate the effect of diet on urine profile. In addition, new applications in the food and beverage industry appear promising. More than 100 compounds, acidic to basic, can be separated. The clinical analyst may be interested in scanning a wide variety of compounds or in rapid separation of only a few compounds. For the latter purpose, the effect of changing the gradient elution program has been investigated, and conditions have been defined for rapid analysis of specific regions of the chromatogram. Additionally, the chromatogram may be simplified by fractionation—for example, by solvent extraction—before high-resolution analysis. The sensitivity of the instrument is often limited by baseline drift caused by absorbance of the buffer. Various methods for compensating for this drift have been investigated. Reproducibility of retention time, response, and computerized data processing are discussed.
Metabolic Profiles: Gas-Phase Methods for Analysis of Metabolites
Authors: Horning E C , Horning M G
Published: January 2020

Multicomponent analyses were carried out for three types of urinary constituents: steroids, acids, and drugs and drug metabolites. The methods were based on gas-phase analytical techniques, which include the use of instruments and instrumental systems for gas chromatography, gas chromatography—mass spectrometry, and mass spectrometry—computerization. After isolating an analytical sample, we prepared derivatives in each instance. Gas chromatography was used for separations, mass spectrometry for identification. These procedures for obtaining metabolic profiles may be used in various ways, including studies of abnormal conditions, drug metabolism, and the effects of drugs on metabolic pathways, as well as for human developmental studies.
Characterization of High-Purity Chemicals for Use as Clinical Laboratory Standards
Authors: Barnard A J , Joy E F , Michelotti F W
Published: January 2020

Some practical approaches to the broad analytical definition of high-purity chemicals for use as clinical laboratory standards are highlighted. Techniques applied include precision gravimetry and titrimetry, differential scanning calorimetry, phase solubility analysis, emission spectrography, flame absorption photometry, polarography, cold-vapor atomic absorption photometry (for mercury), solution photometry, turbidimetry, thin-layer chromatography, as well as general tests, and the measurement of properties. The characterization of various standards is delineated, including standards for calcium, chloride, lithium, magnesium, phosphate, potassium, sodium, creatinine, dextrose, glycine, urea, and uric acid.
Utility of Clinical Chemical Determinations of Drug Concentrations in Biological Fluids
Authors: Vesell Elliot S , Passananti G Thomas
Published: January 2020

Iatrogenic drug toxicity has become a major medical problem. An approach to avoiding adverse reactions arising from drug accumulation is suggested and explored in depth. Large differences in the rates at which individuals metabolize several commonly used drugs are reviewed, because they illustrate the dangers of prescribing drugs solely according to body weight or surface area, and they emphasize the need for more satisfactory guidelines. Direct measurement of certain drugs in blood is suggested as a convenient, economical, and reliable solution to this problem. In healthy nonmedicated subjects, rates of decay of certain drugs are highly reproducible. In spite of large, genetically controlled differences among subjects in rates of drug metabolism, individuals do not vary significantly with respect to the pharmacological effects produced by certain well-defined blood concentrations of most drugs. For this reason, blood concentrations of most drugs may be conveniently divided into three separate ranges: the low range of therapeutic ineffectiveness; the intermediate range, in which the pharmacologic activity of the drug with negligible toxic side reactions is produced; and, finally, the toxic range. Because many potent drugs with a narrow therapeutic index are in use today—both alone and in combination—it is extremely difficult for the physician to maintain his patients consistently within the therapeutic range and outside of the ineffective or toxic range. Toxicity could be appreciably decreased if this approach of measuring drug concentrations in blood were more widely used in selecting and modifying drug dosage. Clinical advantages and limitations of measuring drug concentrations in blood, as well as the pharmacologic and genetic principles underlying them, are discussed.
Excretion of L-Dopa and Its Metabolites in Urine of Parkinson's Disease Patients Receiving L-Dopa Therapy
Authors: Routh J I , Bannow R E , Fincham R W , Stoll J L
Published: January 2020

L-Dopa and its major metabolites were separated from daily 24-h urines from patients with Parkinson’s disease, who were being treated with increasing doses of the drug, up to 4 g per day. An aliquot of each sample was passed through three different ion-exchange columns. Catecholamines (dopamine, epinephrine, norepinephrine, metanephrine, and normetanephrine) were retained on a cation-exchange column, eluted with boric acid, and quantitated by fluorometric analysis. Catechol acids, present in the effluent of the cation-exchange column, were retained on an anion-exchange column. An aliquot of the eluate of the anion-exchange column was used for colorimetric determination of 3,4-dihydroxyphenylacetic acid, while the effluent from this column was used for colorimetric determination of dopa. A second aliquot of the eluate from this column was passed over a column of alumina, which retained all the acidic metabolites except homovanillic acid, which was measured fluorometrically in the effluent from the alumina column. Vanilmandelic acid was determined in another aliquot of each urine sample by use of paper electrophoresis. The excretion pattern elicited suggests a major metabolic pathway for the L-dopa administered to patients with Parkinson's disease.
Manual and Automated Methods for Urea Nitrogen Measurement in Whole Serum
Authors: Wybenga Donald R , Di Giorgio John , Pileggi Vincent J
Published: January 2020

A simple method is described for directly determining serum urea nitrogen, wtihout deproteinization. The urea in 20 µl of serum or plasma is reacted with diacetylmonoxime in the presence of thiosemicarbazide and cadmium ion under acid conditions. The absorbance of the resulting rose-purple solution is measured at 540 nm. Results agreed excellently with those obtained by a reference method that makes use of urease and the Berthelot phenate—hypochlorite reaction for ammonia. An automated adaptation utilizing the AutoAnalyzer is also described, which eliminates the need for a dialyzer. A further advantage is that the same reagents are used for both methods.
Determination of SMA—Mark X1,2 Set Points for Bilirubin by Standard Addition Technique
Authors: Laessig Ronald H , Schwartz Thomas H , Paskey Thomas A
Published: January 2020

A technique based on the standard addition method is described for calibration of the bilirubin channel on the SMA and Mark X analytical systems. Reference sera used for set point calibration contain significant blanks that are compensated in the present technique, which is based on actual bilirubin response of the respective instruments. Precision is improved by use of a least squares technique.
An Improved Delves Cup Atomic Absorption Procedure for Determination of Lead in Blood and Urine
Authors: Olsen Eugene D , Jatlow Peter I
Published: January 2020

The Delves [Analyst (London) 95, 431 (1970)] cup atomic absorption procedure for determination of lead in blood has been studied in detail and modified to permit the direct use of aqueous standards. Precision has been improved by stabilizing the burner mount. The small nonspecific absorption is caused by molecular sodium chloride and potassium chloride, and can be compensated for by including sodium chloride in the aqueous standards. If the cups are pre-coated with albumin, aqueous standards can be used and the more complicated method of additions is obviated. A similar technique was used to examine the analysis of lead in urine.
Kinetic Nephelometric Procedure for Measurement of Amylase Activity in Serum
Authors: Shipe James R , Savory John
Published: January 2020

We developed a kinetic procedure for determination of amylase activity in serum by use of nephelometric measurements. Light scattering from the substrate, a stable suspension of starch, is decreased as amylase hydrolyzes the starch to soluble fragments. Values obtained for serum amylase correlate closely with those determined by a method in which a starch-dye complex is used. Precision of the new procedure is 3.4% (relative standard deviation). Units of amylase activity can either be expressed in terms of milligrams of starch consumed or converted to more conventional amylase units.
Interlaboratory and Intralaboratory Comparison of T3-Uptake Methodology
Authors: Spierto F W , Hubert Ivey Lois , Witter Robert F
Published: January 2020

Triiodothyronine (T3)-uptake values in selected human serum pools were compared by use of Abbott's "Trisorb," Mallinckrodt Nuclear's "Res-O-Mat," Curtis Nuclear's "Tri-lonex," and a standard procedure. In addition, interlaboratory variation was measured among laboratories using the Abbott and Mallinckrodt procedures. Study of methodological variables indicated that incubation time and temperature affect T3 measurement. The Abbott procedure is most liable to variations caused by either time or temperature changes; the Mallinckrodt and Curtis methods are least liable to variations caused by changes in time and temperature, respectively. Between-run variation for sera with low T3-uptake values was greater than within-run variation as measured by the Abbott, Mallinckrodt, or standard procedure. For sera with high T3-uptake values, between-run variation and within-run variation are similar; with the Curtis method this was true for all serum pools. We and the reference laboratories found the Abbott method to be most sensitive in detecting changes in T3-uptake values of samples in the "hyperthyroid" range.
Spot Applicator for Quantitative Thin-Layer and Paper Chromatography, Suitable for Clinical Analysis
Authors: Rosenthal Arthur F , Vargas Marta G
Published: January 2020

Construction and operation of a semiautomatic TLC sample-spotting applicator are described. With the apparatus, multiple samples, each as large as 2.0 ml, can be transferred to a thin-layer chromatographic plate with little or no operator attention. Replicate analyses show a relative standard deviation of 1.35-1.99% without washout; liquid holdup is no more than 3-5%, and is of no significance in the analytical accuracy. The apparatus has been found to be very suitable for quantitative (as well as qualitative) thin-layer chromatographic analysis in the clinical laboratory.
The Relative Merits and Applicability of Kinetic and Fixed-Incubation Methods of Enzyme Assay in Clinical Enzymology
Authors: Moss D W
Published: January 2020

The considerations are discussed that make continuous monitoring of reaction-progress curves superior to fixed-incubation methods in the determination of enzyme activity. Provided that they are used with caution and their limitations are appreciated, fixed-incubation methods continue to fulfill a useful, though diminishing, role in clinical enzymology because of their adaptability to existing patterns of automation. The introduction of suitable mechanized equipment will favor the eventual complete adoption of the kinetic method. However, the use of such equipment should not be at the expense of th important characteristics of the kinetic principle.
Studies of the Stability of 18 Chemical Constituents of Human Serum
Authors: Wilson Sherman S , Guillan Ramon A , Hocker E Virginia
Published: January 2020

The stability of 18 chemical constituents of human serum was measured at various times and temperatures, the measurements being made with the Technicon AutoAnalyzer, by routine N-methods (Technicon laboratory method file number). Data are presented illustrating what happens to human serum under defined conditions of collection and storage. Analysis of the data indicates that under certain conditions the concentration or enzymatic activity of certain constituents may be significantly altered.
Study of Optimum Buffer Conditions for Measuring Alkaline Phosphatase Activity in Human Serum
Authors: McComb Robert B , Bowers George N
Published: January 2020

We have compared 23 compounds, with and without transphosphorylating properties, as buffer systems for human serum alkaline phosphatase activity, with p-nitrophenylphosphate as substrate. Relative enzyme activity in four representative buffers at near-optimal conditions was ethylaminoethanol > diethanolamine > 2-amino-2-methyl-1-propanol > carbonate. Transphosphorylation was demonstrated in the two buffers in which the enzyme was most active, ethylaminoethanol and diethanolamine. The optima for pH, buffer concentration, and substrate for these four systems were studied in detail. 2-Ethylaminoethanol supports the highest enzyme activity of any of the compounds tested. Diethanolamine was shown to have many of the favorable characteristics required for a reference enzyme procedure.
Measurement of Unconjugated 17β-Estradiol in Plasma by Competitive Protein Binding
Authors: Knox B S , France J T
Published: January 2020

A sensitive and quick competitive protein-binding method is described for measuring unconjugated 17β-estradiol in the plasma of women and sheep. One-milliliter aliquots of plasma, with tritiated estradiol standard added as an index to recovery, are extracted with methylene chloride. Plasma extracts of 17β-estradiol are purified and isolated by adsorption on G-15 Sephadex. The purification procedure does not separate 17α-estradiol from 17β-estradiol, but there is less than 0.05% cross reaction in the binding assay. Recovery of 17β-estradiol is 50-55%. Plasma from human twin pregnancies is used as a source of binding protein in the displacement assay. Free 17βestradiol is separated from bound estradiol by ammonium sulfate precipitation. The standard curve lies in the range 0-200 pg, with less than 4% variation between duplicate points. Sensitivity of the displacement curve at zero value is 2 pg. Values for method blanks are 9.8 ± 1.3 pg/ml (SD) (n = 28). Variation between replicates, including between-assay variation, is less than 10%.
Proficiency Evaluation of Clinical Chemistry Laboratories
Authors: Grannis G F , Grümer H-D , Lott J A , Edison J A , McCabe W C
Published: January 2020

The problem of proficiency evaluation of clinical chemistry laboratories is considered in terms of the accuracy, precision, and allowable limits of error of 10 common analytical procedures, and in terms of the proficiency of individual analysts and the occurrence of gross laboratory mistakes. The concept of the operational chart is developed, and its use is illustrated. Operational charts summarize basic quality-control information in a clear, concise, goal-oriented perspective which is useful for evaluating the performance of individual laboratories and for comparing groups of laboratories. The charts aid in identifying major problems relating to the reliability and clinical usefulness of laboratory results, and should facilitate managerial decision-making processes.
Effects of Intra- and Inter-Individual Variation on Distributions of Single Measurements
Authors: Harris Eugene K , DeMets David L
Published: January 2020

When healthy individuals are surveyed to estimate the "normal range" of some measured variable, generally only a single determination of the variable is obtained for each person. The distribution of such values reflects intra-individual variations, (including analytic deviations) as well as the differences among individuals with respect to such parameters as mean or variance. These underlying sources of variation have been expressed in a conditional probability model from which general equations have been derived showing the effects of these variations on the shape parameters (skewness and kurtosis) of a single-sample distribution. These results may help to explain the shape of a given distribution. More generally, they imply that methods of calculating normal ranges would benefit from a study of various mathematical transformations that could convert distributions of almost any shape to approximately gaussian form. Data from recent blood-chemistry studies are used to compare observed shape statistics with those calculated from the model.
Direct Method for Determining Inorganic Phosphate in Serum with the "CentrifiChem"
Authors: Daly John A , Ertingshausen Gerhard
Published: January 2020

A direct method was developed for determining inorganic phosphate in serum, which requires only a single reagent addition. The method quantitates the unreduced phosphomolybdate heteropolyacid at 340 nm and is linear to at least 10 mg of phosphate per 100 ml. Only 10 µl of serum is required. The unique blanking capabilities of centrifugal analyzers permit the "on run" elimination of serum and reagent background absorbances, which are automatically subtracted. Data on precision, correlation, and recovery are presented. Kinetics of the reaction were studied, and theoretical limits of automatic blanking when applied to a first-order reaction are discussed.
Specificity of Accepted Procedures for Urine Creatinine
Authors: Narayanan Sheshadri , Appleton Harold D
Published: January 2020

Specificities of various commonly used procedures for creatinine in urine were evaluated after subjecting pure creatinine or urine (with or without added creatinine) to counter-current distribution (CCD) between acetate buffer (pH 4.6) and n-butanol. After 10 transfers, each phase of each tube was analyzed for creatinine by each of the various procedures, and the resulting data were compared with the theoretical distribution curve for pure creatinine. The data indicate that the original or automated Jaffé reaction is the most nearly specific of the procedures investigated. Thus, the CCD technique, besides being a powerful separatory tool, also permits a physicochemical approach to the evaluation of specificities of standard procedures in clinical chemistry.
Determination of Serum or Plasma Glucose on the "AutoAnalyzer II" by Use of the Hexokinase Reaction
Authors: Widdowson G M , Penton J R
Published: January 2020

An automated method is described for determination of glucose in serum or plasma by use of the hexokinase reaction. The method has good precision and the results correlate well with those from a manual method in which the same reaction is used.
Manual Nephelometric Methods for Immunochemical Determination of Immunoglobulins IgG, IgA, and IgM in Human Serum
Authors: Killingsworth L M , Savory John
Published: January 2020

Manual procedures are presented for determining immunoglobulins IgG, IgA, and IgM in human serum. The three immunoglobulins are quantitated, after reaction with specific antisera, by measuring light scattering by the antigen-antibody complexes. The procedure is standardized by use of pooled human serum with known concentrations of IgG, IgA, and IgM. Results with the present system correlated excellently with results of either radial immunodiffusion or an automated immunochemical procedure. Precision of duplicate determinations for the IgG, IgA, and IgM methods is 5.37, 1.30, and 5.36% (CV), respectively.
Direct Colorimetric Determination of Hippuric Acid in Urine
Authors: Tomokuni Katsumaro , Ogata Masana
Published: January 2020

A direct colorimetric method is described for determination of hippuric acid in urine. Hippuric acid dissolved in pyridine—water (1:1) produces a color (Amax = 410 nm) when benzenesulfonyl chloride is added. With the method based on this color reaction, urinary hippuric acid follows the Beer-Lambert law up to 1 mg/ml.