bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of Optimum Buffer Conditions for Measuring Alkaline Phosphatase Activity in Human Serum
Authors: McComb Robert B , Bowers George N 
Published: January 2020

Abstract
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 &gt; diethanolamine &gt; 2-amino-2-methyl-1-propanol &gt; 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Serum Gamma-Glutamyl Transpeptidase Activity as an Indicator of Disease of Liver, Pancreas, or Bone
Authors: Lum Gifford , Gambino S Raymond 
Published: January 2020

Abstract
Serum γ-glutamyl transpeptidase (GGT), leucine aminopeptidase, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase activities were assayed in controls and in patients with liver, pancreatic, or bone disease. GGT activity was above normal in all forms of liver disease studied (viral hepatitis, cirrhosis, cholecystitis, metastatic carcinoma to liver, pancreatic carcinoma, liver granuloma, and acute pancreatitis). GGT more sensitively indicated hepatic disease than did alkaline phosphatase, much more so than did leucine aminopeptidase. GGT was disproportionately more active in relation to the transaminases in cases of intraor extrahepatic biliary obstruction; the reverse was true in cases of viral hepatitis. GGT activity was normal in children, adolescents, and pregnant women, and in cases of bone disease and renal failure. Kinetic measurement of GGT activity offers a simple, sensitive, and direct means for distinguishing whether bone or liver is the source of increased serum alkaline phosphatase activity. Activity was highest in obstructive liver disease.
An L-Aspartate: 2-Oxoglutarate Aminotransferase Reference Material from Human Erythrocytes: Preparation and Characterization
Authors: Rej Robert , Vanderlinde Raymond E , Fasce Charles F 
Published: January 2020

Abstract
L-Aspartate: 2-oxoglutarate aminotransferase (EC 2.6.1.1) from human erythrocytes is purified for use as a reference material in clinical assays for the enzyme. The procedure involves heat treatment in the presence of a substrate (2-oxoglutarate), ammonium sulfate precipitation, and fractionation with n-butanol. The material is further purified by anion- and cation-exchange chromatography. Specific activity obtainable by a typical preparation is 110 µmol min-1 mg-1 at 30°C. Identical behavior is demonstrated between enzyme in human serum and purified erythrocyte enzyme when substrate concentrations, temperature, and pH are varied. A lyophilized preparation at 4°C is stable for longer than 400 days. Data regarding purity and behavior in currently used clinical assays is described.
Carbon Rod Atomizer Applied to Measurement of Lead in Whole Blood by Atomic Absorption Spectrophotometry
Authors: Kubasik N P , Volosin M T , Murray M H 
Published: January 2020

Abstract
An atomic absorption method is described for determining lead in blood by means of the carbon rod atomizer. With the procedure, only a dilution of the whole blood sample is required, and results are comparable to those obtained by the more generally used atomic absorption flame technique. Advantages of the carbon rod include rapid analysis, simple sample preparation, and small sample volumes.
Cellulose Acetate Electrophoresis of Alkaline Phosphatase Isoenzymes in Human Serum and Tissue
Authors: Fritsche H A , Adams-Park H R 
Published: January 2020

Abstract
We describe a new electrophoretic method for the characterization of human serum and tissue alkaline phosphatases on cellulose acetate plates. Enzymes are localized fluorometrically with the substrate α-naphthol AS-MX phosphate or colorimetrically by coupling the reaction product with Fast Blue RR. Both localization techniques are sensitive enough to demonstrate isoenzyme patterns in micro-scale samples of normal sera. Our electrophoretic studies indicate that sera of children and adults normally contain isoenzymes originating from both liver and bone. The high sensitivity of the method allows the use of normal sera as markers rather than tissue extracts, and isoenzyme patterns may be visually assessed after heat inactivation and chemical inhibition. The method is suitable for the electrophoretic fractionation of alkaline phosphatase in large numbers of sera, with equipment and technique familiar to many laboratories.
Coulometric Determination of Activity of Acid or Alkaline Phosphatases in Serum
Authors: Brooks Marvin A , Purdy William C 
Published: January 2020

Abstract
A constant-current coulometric technique is described for measuring acid or alkaline phosphatase activity in serum. Electrogenerated bromine is used as the titrant of phenol enzymatically released from phenyl phosphate. A biamperometric end-point detection system is used, with an applied potential of 135 mV. Titrations are performed at pH 1 with use of a generating electrolyte of 0.5 molar KBr in 0.05 molar H2SO4. A procedure is described for determining serum alkaline phosphatase activity by use of 2-amino-2-methyl-1-propanol (0.25 mol/liter, pH 10.25) with Mg2+ activator (1 mmol/liter), and for determining serum acid phosphatase activity in citrate buffer (0.1 mol/liter, pH 4.9). Results compare favorably with those of the method of Kind and King [J. Clin. Pathol. 7, 322 (1954)].
Ultraviolet Spectrophotometric Measurement of Chlordiazepoxide in Plasma
Authors: Jatlow Peter 
Published: January 2020

Abstract
A simple ultraviolet spectrophotometric method is described for measurement of chlordiazepoxide in blood. The drug is extracted into chloroform at pH 7.4 and, after a NaOH wash, extracted back into HCl. The drug is identified by its characteristic ultraviolet spectra at acidic and basic pH’s, and quantified from the absorbance value measured at the major acid peak of 247 nm. Although certain weakly basic drugs theoretically could interfere if present concurrently with chlordiazepoxide, we have not seen this during three years of experience. This procedure is easily combined with established methods for barbiturates and glutethimide. Specimens from more than 60 cases of documented chlordiazepoxide ingestion have had concentrations ranging from 0.2 to 6.6 mg/100 ml by this procedure.
Low Aspartate Transaminase Activity in Serum of Patients Undergoing Chronic Hemodialysis
Authors: Wolf Paul L , Williams Dorothy , Coplon Norman , Coulson Alan S 
Published: January 2020

Abstract
Glutamic-oxalacetic transaminase (aspartate transaminase) activity is decreased in serum of patients undergoing long-term hemodialysis. The reason may be the repeated dialysis, pyridoxine depletion, or both.
Assay of Human Plasminogen in Plasma by Affinity Chromatography
Authors: Zolton Raymond P , Mertz Edwin T , Russell Henry T 
Published: January 2020

Abstract
A direct, rapid (&lt;3h), and simple technique is described for assaying human plasminogen by affinity chromatography. Plasma is passed over a column of Sepharose—butyl aminobenzoate. The unretarded proteins, including plasmin, are washed out with phosphate—saline, pH 7.4, buffer. The bound plasminogen is released by adding lysine, 0.1 mol/liter, to the buffer and the plasminogen concentration in the eluate is determined by absorbance measurements at 280 nm. A value of 195 ± 10 mg/liter was found for pooled donor plasma from normal individuals. Twenty-one normal women, age 21 to 46, had an average value of 194 ± 38 mg/liter, while 14 pregnant women in the third trimester had an average value of 250 ± 55 mg/liter. The range in 30 hospital patients with various ailments was 122 to 265 mg/liter.
Exploratory Experiments in Direct Evaluation of Renal Metabolic Capabilities
Authors: Lacy Sushil S , King J Stanton 
Published: January 2020

Abstract
In experiments on bloodless maintenance of the kidney during renal surgery, some ancillary observations were made to test the idea that the canine kidney in situ could satisfactorily be so used to study renal metabolism. Results of these tentative biochemical experiments are reported here in the hope that others will be encouraged to continue them.
Dynamic Introduction of Whole-Blood Samples into Fast Analyzers
Authors: Scott Charles D , Mailen James C 
Published: January 2020

Abstract
A new automated method of sample preparation and introduction that may circumvent the problems of measurement of micro-scale quantities of samples and preparation of serum or soluble blood fraction is being developed for use in fast analytical systems based on the GeMSAEC principle. This method involves the dynamic introduction of reagents or blood samples into the centrifugal field of the Fast Analyzer during rotation of the rotor. The rotor can be designed to fractionate the fluid into discrete, measured portions that are transferred to the cuvets for photometric monitoring. Whole-blood samples can be directly introduced into the rotating rotor where, after fractionation into measured volumes, the particulates are automatically removed by the centrifugal field and the resulting measured quantities of plasma are transferred directly to the cuvets. The dynamic proportionation of reagents, serum, and whole blood has been shown to be precise, and automatic analyses for specific chemicals have been performed on whole blood samples with a coefficient of variation of less than 2%.
Simultaneous Multicolumn Operation of the UV-Analyzer for Body Fluids
Authors: Pitt W Wilson , Scott Charles D , Jones Guy 
Published: January 2020

Abstract
At the current state of development, high-resolution liquid chromatographs for analyses of complex physiologic fluids require relatively long analysis times and consequently the rate at which analyses can be done is limited. This rate can be increased by decreasing the analysis time or by use of multiple columns to process several samples in unison. An automated multicolumn high-resolution chromatograph for separating ultraviolet-absorbing molecular constituents of body fluids is being developed. The sample-handling capacity was increased several-fold with minimum added cost by using many of the components of the single-column analyzer. Results from routine use of a UV-Analyzer with two columns in parallel show that parallel operation is not only feasible but highly advantageous. The design of a high-pressure, multiple-column, sample injection valve for simultaneous injection of samples on different columns is discussed.
Enzymatic Kinetic Rate and End-Point Analyses of Substrate, by Use of a GeMSAEC Fast Analyzer
Authors: Tiffany T O , Jansen J M , Burtis C A , Overton J B , Scott C D 
Published: January 2020

Abstract
Enzymatic substrate analysis is an attractive means of analysis in clinical chemistry because of its sensitivity and specificity. The GeMSAEC Fast Analyzer, in conjunction with a small computer, provides a means of performing routine enzymatic substrate analysis and offers the following advantages: (a) selectivity of approaches to enzymatic analysis, i.e., end-point or kinetic; (b) essentially parallel analyses of multiple samples, yielding a unique method for performing kinetic fixed-time analysis; (c) on-line data reduction, resulting in rapid calculation and output of results and the minimization of data handling errors; and (d) a small reagent volume per test (400 µl), which reduces the cost of analysis. The analysis of substrate with enzymatic end-point and kinetic procedures is examined by use of a computer-interfaced Fast Analyzer. Computer programs were written to facilitate this study. Glucose (hexokinase/GPD), urea (urease/GMD), and uric acid (uricase) have been used as examples in evaluating both end-point and kinetic analyses. The advantages and limitations of each type of analysis are presented, with the emphasis being placed on enzymatic substrate analysis and means by which the computer-interfaced Fast Analyzer can facilitate both end-point and kinetic analyses.
Factors Affecting the Results of Serum Cholesterol Determinations: An Interlaboratory Evaluation
Authors: Fasce Charles F , Vanderlinde Raymond E 
Published: January 2020

Abstract
We present results of an interlaboratory survey of cholesterol assays in which methodology, standardization technique, type of standard, reagent source, and control sera used are considered. Each of these factors is evaluated, on both clear and icteric sera, with respect to accuracy, interlaboratory precision, and associated random error. We find that most participants use direct techniques, that these laboratories do not use correction procedures where these are needed, and that not all extractants effectively prevent bilirubin interference. Our data illustrate that precision on clear sera is best by direct procedures, but not in the presence of bilirubin. Participants uniformly exhibit better intralaboratory precision than interlaboratory agreement, regardless of the variable being studied. It is appropriate to consider the interactions of variables if a technique is to be properly evaluated.
Determination of Glucose in Serum and Whole Blood: Statistical Relationships between Values Obtained by Different Methods
Authors: Geeting David G , Suther Charles A , Sylbert Philip 
Published: January 2020

Abstract
Several methods are available for determination of glucose in whole blood and serum. When comparing the results of these methods on a single blood sample, one may find significantly different values. Here, equations are provided for converting values for whole blood glucose to values for serum glucose, obtained by different methods.
A Discussion of Enzyme Reference Materials: Applications and Specifications
Authors: Fasce Charles F , Rej Robert , Copeland William H , Vanderlinde Raymond E 
Published: January 2020

Abstract
Clinical laboratories estimating enzyme activity in serum are using commercial lyophilized sera for four major purposes. These uses—as a standard and for intermethod, intramethod, and precision control—are segregated, and specifications for each deployment are examined in terms of requirements for the enzyme material: freedom from interfering or indicator enzymes and chromogens; high specific activity; inclusion of optimal cofactor concentrations; commutability, human properties and source; the presence of a single isoenzyme; and stability. The effects of serum matrix and variable assay conditions on the utility of enzyme materials are analyzed. Specifications differ for each enzyme material application. The compatibility of commercial lyophilized sera containing aspartate aminotransferase activity with several cited specifications is assessed
Determination of Lead in Blood and Urine by Anodic Stripping Voltammetry
Authors: Searle Bernard , Chan Wing , Davidow Bernard 
Published: January 2020

Abstract
An anodic stripping procedure for determining lead in blood and urine was evaluated, and methods of calibration were developed. The technique requires as little as 50 µl of blood or 0.5 ml of urine. Comparisons were made between results obtained by anodic stripping voltammetry, for finger-puncture blood, and by atomic absorption spectrophotometry, for venous blood from 200 children. The two methods were also compared with respect to lead in urines from patients hospitalized for suspected lead poisoning and in urines from normal healthy volunteers. Major advantages of the anodic stripping method are its increased sensitivity and lower cost as compared to many current methods for detecting and measuring lead
Estimating Correlations from Single-Sample Distributions of Measurements
Authors: Harris Eugene K 
Published: January 2020

Abstract
The correlation coefficient between two variables (e.g., blood constituents) in normal individuals (or in patients) is usually estimated from measurements of both variables in single samples from the individuals studied. This coefficient is supposed to represent a correlation between the two variables within the average individual. However, unless all the subjects have identical mean values, the "single-sample" coefficient also reflects the correlation of mean values across individuals, generally different from the average intra-individual correlation. Even when both intra-and interindividual correlations are equal, the "single-sample" coefficient underestimates the true intra-individual correlation unless corrected for measurement errors. Using data from normal individuals, two examples are presented: in one case (calcium-total protein), the corrected single-sample coefficient appears to be an unbiased estimate of the desired correlation, whereas in the other example (albumin-globulins), it is quite misleading. These examples support the need for multiple, independent samples from each individual to assure a valid estimate of the average intra-individual correlation between two variables