bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyses on Heat-coagulated Blood and Serum
Authors: London Morris , Freiberger Ida A , Marymont Jesse H 
Published: January 2020

Abstract
The "standard" heat-clot method of London and Marymont is shown here to be applicable to the determination of creatinine. With this method creatinine can be assayed in very small quantities of serum, and only a conventional laboratory reagent, alkaline picrate, is required. A new fast technic has been developed in which extraction of the clot is carried out for only 10 min. at a high temperature. In addition, the heat-clot method used in conjunction with Lloyd's reagent lends itself to the determination of "true" creatinine values.
Comparison of Methods for Pregnanediol Determination
Authors: Wallach Edward E , Touchstone Joseph C 
Published: January 2020

Abstract
A gas chromatographic method of pregnanediol determination has been carried out on 24-hr. urine specimens collected during various phases of the menstrual cycle and during pregnancy. Pregnanediol values were correlated with endometrial histology and cycle day in nonpregnant subjects, and with duration of gestation during pregnancy. Determinations were performed on free pregnanediol and on the acetylated derivative, both with and without the inclusion of a permanganate wash. One patient was followed through 2 ovulatory cycles with 24-hr. urinary pregnanediol determinations, using gas-liquid chromatography of the free compound. Comparisons were also made between pregnanediol values as determined by gas chromatography and by column chromatography.
The method using gas chromatography is rapid and reproducible, yielding results comparable to those obtained using a colorimetric technic. The gas chromatographic method is applicable during pregnancy, and also in the nonpregnant state for evaluating the occurrence of ovulation. There appears to be no advantage in the performance of a permanganate oxidation or in the production of the diacetate derivative.
Serum Creatine Phosphokinase: Evaluation of a Commercial Spectrophotometric Method
Authors: Hess Joseph W , MacDonald Roderick P , Natho George J W , Murdock Kenneth J 
Published: January 2020

Abstract
The clinical and laboratory applications of an assay method for serum creatine phosphokinase (CPK) utilizing a reagent capsule were investigated. Continuous recording of the change in absorbance at 340 mµ, during the assay period gave a slightly sigmoid curve. The time interval between serum addition and the beginning of the linear portion of the absorbance curve varied with the level of enzyme activity. With samples of low activity, up to 8 min. elapsed before the linear phase began. The rate of change in absorbance increased in a linear fashion with respect to increasing CPK concentration, up to a level of about 370 U. When serum samples with activity above this level were diluted and reassayed, and the data appropriately corrected for dilution, significantly increased activity could be demonstrated in the diluted samples.
Adenylate kinase from hemolyzed erythrocytes may interfere with measurement of CPK activity in this assay system. This does not present a problem if samples with visible hemolysis are excluded.
The range of normal human serum CPK values recommended for this method is 0-40 U./L. at 30°. Abnormal values in patients with injuries or diseases of skeletal muscle were as high as 55,000 U. After acute myocardial infarction, elevated serum CPK levels were detected within 4 hr. after the onset of chest pain. In some of these patients CPK activity did not return to normal for a week or more.
Properly used, this method provides a reliable and convenient assay procedure for serum CPK activity.
A Micromethod for the Determination of Ferroxidase (Ceruloplasmin) in Human Serums
Authors: Johnson D A , Osaki S , Frieden E 
Published: January 2020

Abstract
A sensitive method for the detection of ceruloplasmin (ferroxidase) in human serums, using Fe(II) as the substrate, is described. Initial Fe(II) concentrations of 30 and 120 µM may be used, depending on the sensitivity of the spectrophotometer, for the determination of the rate of Fe(III) -transferrin formation following the oxidation of Fe(II) by ceruloplasmin (ferroxidase). Advantages of this method over other methods employing p-phenylenediamine as a substrate and the standardization of enzyme activity in terms of international enzyme units are discussed.
Determination of Sodium in Urine by Specific Ion Electrode
Authors: Annino Joseph S 
Published: January 2020

Abstract
A method has been developed for determination of sodium concentration (activity) in urine using a glass electrode designed to be especially sensitive to sodium ion activity. The urine is diluted 2:20 with Tris buffer (pH 8.0) and sodium activity measured by dipping a sodium electrode and calomel reference electrode in the diluted specimen and obtaining a millivolt reading with a sensitive pH meter. The sodium concentration is then calculated from a predetermined standard curve. Concentrations of 0-200 mEq./L. may be read using the same dilution. Blind comparisons of sodium concentrations obtained by flame photometry and by sodium ion electrode showed excellent agreement.
Alkaline Degradation of Inulin and Its Structural Implications
Authors: BeMiller J N , Steinheimer T R , Allen Earl E 
Published: January 2020

Abstract
Alkaline degradation of inulin under controlled conditions shows that not all molecules in an inulin preparation are nonreducing and, thus, alkali-stable and suitable for clinical measurements. Reducing "inulin" molecules are degraded by the normal beta-alkoxy carbonyl mechanism, and the main product of degradation in calcium hydroxide solution is "α"-D-glucosaccharinic acid. An inulin preparation can be made alkali- stable by sodium borohydride reduction. There appears to be a difference in the alkali lability of inulin and other fructan preparations obtained from different sources.
Automated Alkaline Phosphatase Determination
Authors: Klein Bernard , Kaufman James H 
Published: January 2020

Abstract
An automated procedure for the determination of serum alkaline phosphatase uses phenolphthalein monophosphate as the substrate. Important assets of this substrate are: (1) A chromogenic product is enzymically produced and can be measured directly; (2) Bilirubin does not interfere, thus eliminating the need for a control analysis. Excellent agreement is obtained when the enzyme activities determined by the present method and by the automated p-nitrophenylphosphate procedure are compared.
Microdetermination of Inorganic Phosphate, Phospholipids, and Total Phosphate in Biologic Materials
Authors: Biologic E S , Foà P P , Zak B 
Published: January 2020

Abstract
A rapid, reproducible, and sensitive procedure for the determination of phosphate in several biologic materials is described Organic phosphate is rapidly converted to orthophosphate by digestion with a nitric acid-calcium ion mixture. The acid destroys the organic material while the calcium ion prevents loss of phosphate or its conversion to an unmeasurable form. Inorganic phosphate can be determined in the presence of labile organic phosphates since phosphate liberated after the color reaction has been initiated cannot interfere by forming further color. Even if phosphate were deliberately added after the color reaction had started, it could not react in the described system. The method may be applied to the determination of phosphate present in ultramicro quantities. It is unnecessary to extract the heteropoly acid complex either to increase sensitivity or to protect the color complex formed from interference of phosphate hydrolyzed during the process of color formation.
Electrophoretic Determination of Vanilmandelic Acid (VMA) in Urine by Direct Application to Cellulose Acetate
Authors: Butler Thorne J 
Published: January 2020

Abstract
The VMA in urine was quantitated electrophoretically by application of urine to cellulose acetate. Separation of several hydrophenolic acids is distinct. VMA is detected at 0.1-µ.g. levels. Normal values on 400 specimens was 4.0 ± 2.0 mg./24 hr.
A Manual Fluorometric Paper Disc Method for Detecting Phenylketonuria
Authors: Searle Bernard , Mijuskovic Milutin B , Widelock Daniel , Davidow Bernard 
Published: January 2020

Abstract
A method is described for a spectrophotofluorometric determination of phenylalanine. The amino acid is extracted from a spot of blood which is found to be stable when dried on filter paper. The method is relatively simple and the analysis may be completed on the day the sample is received.
Isolation of Albumin from Human Serum by Means of Trichloroacetic Acid and Ethanol
Authors: Iwata Takuzo , Iwata Hiromi , Holland James F 
Published: January 2020

Abstract
A rapid method for nearly quantitative isolation of human serum albumin is described. The present technic (1) is a modification of the Schwert method (2). In the present method 4 ml. of serum is precipitated with trichloroacetic acid in a final concentration of 5% (w/v). The precipitate is washed with TCA, and after aqueous suspension, ethanol is added to a final concentration of 80%. The undissolved globulin is washed with ethanol and the solubilized albumin used for quantification, characterization, and isotope counting.
Recovery of added human serum albumin was approximately 98%; recovery of added 131I albumin was 90%.
Cellulose acetate electrophoresis showed a single band, and agar diffusion produced one precipitate line. Immunoelectrophoresis with anti-human serum revealed one or two very faint arcs in the α-, or α- and β-globulin regions, in addition to the major arc of albumin.
The method has shown excellent reproducibility in replicate analyses of normal and pathologic serums.
A Modified Total Serum Cholesterol Method to Eliminate the Effect of High Bilirubin Levels
Authors: Jordan William J 
Published: January 2020

Abstract
When a high molecular weight dextran sulfate solution was added to serum in the presence of calcium ions, a lipoprotein complex was precipitated that contained the total serum cholesterol. The incorporation of this precipitation step in the procedure for total cholesterol determinations eliminated errors due to high serum bilirubin levels.
The Determination of Normal Ranges from Routine Laboratory Data
Authors: Neumann George J 
Published: January 2020

Abstract
A method is described which is potentially capable of closely estimating the normal range from laboratory data. The estimation is made on probability paper using a purposely truncated form of the "normal" distribution. A fictitious set of data has been used to illustrate the efficiency of estimation of normals. The method has been used to estimate the normal range of blood urea.
Detection of Metabolic Disorders
Authors: Berry Helen K , Leonard Carolyn , Peters Helen , Granger Mary , Chunekamrai Naree 
Published: January 2020

Abstract
A scheme for detection of metabolic disorders utilizing commercial dip tests, spot plate tests, and paper chromatographic tests is presented. Specific details are given for preparation and development of chromatograms for routine screening of urine specimens for disorders of amino acid and carbohydrate metabolism. Specialized tests for confirming positive findings in the screening procedures are described. The results are interpreted with regard to the variations encountered in testing normal infants and children, children hospitalized with a variety of diseases, and mentally retarded children. Examples of specific and generalized aminoacidurias are given.
Rapid Methods for the Determination of Pregnanediol in Urine
Authors: Brombacher P J , Gijzen A H J , Verheesen P E 
Published: January 2020

Abstract
Pregnanediol determination in urine was performed by alumina-column chromatography followed by reaction with sulfuric acid and by gas chromatography. After enzymatic hydrolysis of the conjugated urinary steroids, there is a very good agreement between both methods.
Proposals for Standardization of Total Protein Assays
Authors: Peters Theodore 
Published: January 2020

Abstract
The Standards Committee of the AACC presents a discussion of the nature of total serum protein and the problems associated with its determination. Proposals are made that protein be defined as polypeptide material, and that a reference preparation be promulgated for interlaboratory use. The reference material suggested is bovine serum albumin, produced to rigid specifications and distributed as a stable 7% (w/v) solution, the concentration of which has been established by careful dry weight assay. Comments of readers are invited.
A Biuret Method for Determination of Protein in Normal Urine
Authors: Savory John , Pu Pin H , Sunderman F William 
Published: January 2020

Abstract
A biuret method has been developed which provides quantitative measurements of protein in normal urine without interference from drugs or pigments. This method is intended for use in monitoring clinical trials of new drugs—to detect nephrotoxicity. Protein is precipitated from duplicate samples of urine by addition of cold ethanolic phosphotungstic acid. The protein precipitates are separated by centrifugation and washed with ethanol. Protein from one of the duplicate samples is dissolvel in biuret reagent. Protein from the second sample is dissolved in an alkaline tartrate reagent which is identical to the biuret reagent, excepting that copper sulfate has been omitted. After 20 min., the differential absorbance of the two samples is measured at 540 mµ. The limit of sensitivity for detection of protein in urine is 0.5 mg./100 ml. The coefficient of variation of replicate analyses of protein in normal urine is 4.2%. The recovery of protein added to urine averages 103 ± 3%. Analyses of urinary protein by the biuret procedure provide close correlation with measurements by an amido black staining method. Systematic search has failed to reveal interference from urinary pigments, compounds, or drugs which are normally or occasionally encountered in hospitalized patients. In 24-hr. collections of urine from 28 healthy adults, the protein concentrations averaged 6.2 mg./100 ml. (range 3.0-12.2), and the protein excretions averaged 77 mg./day (range 40-150).
Mercurimetric Determination of Chloride in Biologic Fluids Using 2-(8-Hydroxyquinolyl-5-azo)-Benzoic Acid (QBA*)
Authors: Gindler E Melvin 
Published: January 2020

Abstract
2-(8-Hydroxyquinolyl-5-azo)-benzoic acid (QBA) may be substituted for s-diphenylcarbazone as an indicator in the direct mercurimetric titration of chloride ion in biologic fluids. Both indicators give color changes at the same point in the titration. In dilute nitric acid, the Hg(II)-QBA complex is rose-red, whereas unmetallized QBA is orange.
The Determination of Triglycerides in Plasma and Tissues
Authors: Sardesai Vishwanath M , Manning Joan A 
Published: January 2020

Abstract
A simple method for the determination of plasma and tissue triglycerides is described. This procedure involves the extraction and saponification of triglycerides, the oxidation of the glycerol moiety to formaldehyde, and the conversion of formaldehyde to a yellow-colored compound, 3,5 diacetyl-1-4 dihydrolulidine, the intensity of which is determined spectrophotometrically. The recoveries of triglycerides added to plasma and tissues have been satisfactory. Plasma samples obtained from normal human subjects are found to have triglycerides in the range 83-200 mg./100 ml. From the standpoint of sensitivity, simplicity, and time required, this technic is believed to be an improvement over previously described procedures for triglyceride determination.
Determination of Carbon Monoxide in Blood by Gas Chromatography
Authors: Collison Harold A , Rodkey F Lee , O'Neal John D 
Published: January 2020

Abstract
A method for the determination of CO content in blood is described. Carbon monoxide bound to hemoglobin is released by hemolysis and reaction with K3Fe(CN)6 in a closed system. The gases liberated are then swept onto a 5 A molecular sieve column where CO is separated from other blood gases. The CO, after catalytic reduction to methane, is detected by flame ionization. The method is rapid, specific, and sufficiently sensitive to permit analysis of 0.1-ml. samples of normal blood. The accuracy of the method, expressed as the coefficient of variation (S.D. x 100/mean), is 1.8% for normal human blood.
Use of Dansyl Derivatives and Mass Spectrometry for Identification of Biogenic Amines
Authors: Creveling C R , Kondo K , Daly J W 
Published: January 2020

Abstract
A useful technic for the isolation, separation, and identification of biogenic amines as fluores ent dansyl derivatives is described. A thin-layer chromatographic system is presented for the separation of the dansyl derivatives of phenethylamines from their corresponding β-hydroxyl derivatives, of primary amines from their corresponding N-alkylated derivatives, and of the components present in an extract of mammalian heart. Mass spectrums of dansyl derivatives of various amines and amino acids are presented to illustrate parent ion mass determination. This technic was applied to the identification of various amines present in mammalian heart. Identification was based on cochromatography and identity of parent ion mass with authentic compounds. Piperidine, dimethylamine, phenethylamine, methylamine, phenethanolamine, putrescine, spermidine, spermine, and tyramine were identified.
Determination of Serum Albumin
Authors: Keyser J W 
Published: January 2020

Abstract
Good agreement was obtained between an electrophoretic and an immunoprecipitation method for serum albumin, and it is suggested that these offer a means of determining serum albumin concentration with reasonable accuracy. The methyl orange dye-binding method tends to give slightly higher results in disease and occasionally larger discrepancies as compared with the electrophoretic and immunoprecipitation methods, but results are little affected, if at all, by the presence of large amounts of paraproteins. The dye-binding method appears to be ideal for population surveys.
Ultraviolet-absorbing Urinary Components of Mentally Retarded Children and Schizophrenic Adults
Authors: Lis Adam W , Bijan Roman , Lis Elaine W , de Hackbeil Konrad F 
Published: January 2020

Abstract
Urinary excretion of ultraviolet-light-absorbing end products of metabolism was studied in mentally retarded children and schizophrenic adults. Excretion of the major end product of pyrimidine metabolism, pseudouridine (5-ribosyluracil), and one of the catabolic derivatives of nicotinic acid, N-methyl-2-pyridone-5-carboxamide, were both found to be depressed in more than half the mentally retarded children and all the schizophrenic adults studied. In addition, a number of previously unidentified components have been found in both types of mental abnormality, as well as in control subjects, some of which components appear to be present in abnormal quantities.
Control Serum Preparations
Authors: Logan James E , Allen Rovelle H 
Published: January 2020

Abstract
A total of 17 different commercial control serums prepared by 6 manufacturers were examined to determine the accuracy of labeled values for as many as 9 constituents. All serums were analyzed by generally acceptable reference procedures. Several lots of each product were checked at approximately 6-month intervals up to 2 years or more to assess their stability on storage. It is concluded that commercial control serums should not be used in place of a primary standard when the constituents to be assayed can be obtained in a relatively pure form and a stable solution can be prepared.
Clinical Chemical Reagent Tablet Weight Distribution
Authors: Gindler E Melvin , Ishizaki Robert T 
Published: January 2020

Abstract
A study of the weights of 121 tablets, intended for clinical chemical purposes, showed a normal distribution, with 95% of the tablets being within ± 8% of the mean weight (21.8 mg.). The substrate is pH 10.2 (37°), falling about 0.6 pH units when serum is added.
Automated Carbohydrate Analysis of Physiologic Fluids
Authors: Jolley R L , Freeman M L 
Published: January 2020

Abstract
Automated carbohydrate analysis can be useful clinically in the research laboratory as an aid in understanding the fundamental role of carbohydrates in metabolism, including their pathologic significance. An analytic system being developed at our laboratory utilizes an automated carbohydrate analyzer to chromatograph borated physiologic fluids while using strongly basic anion-exchange resin. The eluted carbohydrates are detected by sulfuric acid-phenol colorimetry. The carbohydrate analyzer used in this experimental work should become a useful tool in the clinical laboratory.
Normal and diabetic human urine and blood serum have been chromatographed and significant differences established. As many as 38 peaks have been observed in the complex urine chromatograms. Using cochromatographic technics, 14 peaks have been tentatively identified as sucrose, raffinose, N-acetylglucosamine, maltose, lactose, ribose, fructose, arabinose, fucose, galactose, xylose, mannoheptulose, glucose, and glucose-1-phosphate. All except fucose have been quantified. Blood serum chromatograms consist of a major glucose peak and several smaller peaks indicating traces of other sugars. Melibiose has been used as an internal standard in chromatograms to determine recovery, resolution, and reproducibility. With the present technic, the lower limit of detectable sugar in physiologic fluids is in the 1-µg. range.
A Continuous Spectrophotometric Method for the Determination of Leucine Aminopeptidase
Authors: Knight J A , Hunter D T 
Published: January 2020

Abstract
A new method to assay the enzyme, leucine aminopeptidase (LAP; L-leucyl-peptide hydrolase—3.4.1.1), is described. The technic is an extension of the conventional glutamic-pyruvic transaminase (GPT) reaction. Serum LAP is allowed to react with the substrate L-leucyl-L-alanine to quantitatively generate alanine. This alanine, in the presence of excess α-ketoglutaric acid and GPT, rapidly forms pyruvate, which is converted to lactate by excess lactic dehydrogenase (LDH). Reduced nicotinamide adenine dinucleotide (NAD) is quantitatively oxidized in this reaction. The change in reduced NAD concentration is followed by continuous spectrophotometry at 340 mµ.
Determination of Urinary Testosterone and Epitestosterone in Men, Women, and Children
Authors: McRoberts J William , Olson Arthur D , Herrmann Walter L 
Published: January 2020

Abstract
A new, relatively simple method for simultaneous determinations of urinary testosterone and epitestosterone is described. The novel feature is the periodic oxidation of testosterone and epitestosterone glucuronides with sodium metaperiodate. The chromatographic purification of the ether extracts consisted of alumina-column chromatography, followed by thin-layer chromatography on silica gel of free testosterone and epitestosterone and their trimethylsilyl ether derivatives. The final quantitation was carried out by gas-liquid chromatography.
Average testosterone and epitestosterone excretion in 11 normal male subjects was 61.3 µg./24 hr. (range 9.7-109.7) and 45.8 µg./24 hr. (range 3.7-111.0), respectively; in 10 normal female subjects, 8.8 µg./24 hr. (range 2.1-13.8) and 10.7 µg./ 24 hr. (range 0.8-18.9), respectively; and in 7 normal children under 11 years of age, 1.7 µg./24 hr. (range 0.3-3.9) and 1.4 µg./24 hr. (range 0.4-3.2), respectively.