bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method of assessing serum triiodothyronine concentrations that is independent of subject's age and variations in concentrations of binding proteins in serum.
Authors: Mardell R , Gerson M 
Published: January 2020

Abstract
Pairs of values for serum triiodothyronine and serum triiodothyronine binding capacity were represented as maps of points for euthyroid populations (including subjects who were pregnant or were receiving estrogens) in the age groups 18-50, 51-64, 65-79, and greater than 80 years (504 subjects) and thyrotoxic populations in the same age groups (207 subjects). For each age group the two populations were effectively separated bythe technique. Statistical analysis by the method of principal components justified the combination of all the age-related maps into a single map, allowing the assessment of serum triiodothyronine regardless of age or concentration of binding proteins in serum. The overlap of the combined populations was less than 1%. The method proposed is superior to a calculation of free triiodothyronine index in several respects.
A sensitive manual enzyme immunoassay for thyroxine.
Authors: Schall R F , Fraser A S , Hansen H W , Kern C W , Tenoso H J 
Published: January 2020

Abstract
We describe an immunoassay for thyroxine in serum. In the assay specific antibody covalently bonded to latex particles is used, along with horseradish peroxidase as the label, and o-phenylenediamine as the chromogen. The flexible protocol is designed for manual execution. Performance is similar to that of the highest-sensitivity thyroxine radioimmunoassays. Results correlate well with radioimmunoassay (r = 0.99, slope = 0.93, y-intercept = 2.4 microgram/liter for 201 samples) and an automated enzyme immunoassay (r = 0.97, slope = 0.99, y-intercept = 4.7 coefficients of variation are less than 7.2% over the entire useful range of the assay (20--240 microgram/liter). The limit of detection is less than 94 pg/tube at 20 microgram/liter. Only D-thyroxine is known to interfere with serum assays. This assay has no discernible protein effect from 40 to 80 g of protein per liter, unlike many thyroxine radioimmunoassays. Serum preservatives known to be peroxidase inhibitors do not adversely affect assay performance because of the 56-fold dilution in the final assay mixture. Hemolyzed serum and EDTA-treated plasmas are unsuitable for this assay.
Column-chromatographic separation of isoenzymes of aspartate aminotransferase.
Authors: Sampson E J , Miller S A , McKneally S S , Whitner V S , Hannon W H , Burtis C A 
Published: January 2020

Abstract
We describe a column-chromatographic method for separating the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase in human serum. Bed height of the ion exchanger, pH, and salt concentrations in the eluting buffers are shown to be variables affecting the separation of the isoenzymes. Under the optimized conditions selected for this study, a 30% increase in volume was observed in one fraction, associated with changing the salt concentration of the eluting buffer and attributed to a contraction of the DEAE-Sephadex A-50. Elution profiles (enzyme activity vs. fraction number) were examined with highly purified mitochondrial and cytoplasmic isoenzymes of human origin in bovine serum albumin and human serum. Recovery of the enzyme in the eluted fractions averaged 102% (SD, 2.0%) for specimens prepared from the purified isoenzymes and 104% (SD, 10.7%) for 38 human serum specimens. The separation technique showed linearity to catalytic concentrations in excess of 200 U/liter (reaction temperature 30 degrees C) for each isoenzyme. Additional information is presented regarding among-day precision and the effect of specimen dilution.
A non-barbital buffer for immunoelectrophoresis and zone electrophoresis in agarose gels.
Authors: Monthony J F , Wallace E G , Allen D M 
Published: January 2020

Abstract
We describe buffer for both immunoelectrophoresis and zone electrophoresis procedures in agarose gels, Tricine [N-tris(hydroxymethyl)methylglycine] and Tris [2-amino-2-(hydroxymethyl)-1,3-propanediol] being the main components. This buffer eliminates the procurement cost and inventory control associated with formulation of barbital buffers. We compare it with other common buffer formulations.
Enzyme immunoassay for gentamicin.
Authors: Standefer J C , Saunders G C 
Published: January 2020

Abstract
We describe a gentamicin assay in which a peroxidase-gentamicin conjugate competes with gentamicin for binding to a gentamicin antibody adsorbed to a polystyrene solid phase. The assay can be completed in 30 min and requires 50 microliter of diluted serum. The precision and accuracy are equivalent to that of a radioimmunoassay technique and the reagents are stable for several months.
Proteinuria: accuracy and precision of laboratory diagnosis by dip-stick analysis.
Authors: James G P , Bee D E , Fuller J B 
Published: January 2020

Abstract
We studied and compared results of two urine dip-stick procedures for protein with those of quantitative measurements of total protein and albumin in urine. Sensitivity, specificity, and predictive value of "normal" and "abnormal" dip-stick results, assay efficiency, technologist precision, and method association were determined. Precision was poor, attributable largely to variation within each technologist. Relative to a defined measure of precision, technologist performance appears to be uniform within each product. Patients' urinary protein concentrations of less than 200 mg/liter can be distinguished from concentrations greater than 3000 mg/liter with confidence by dip-stick procedures. Urin samples with low albumin/total protein ratios were frequently falsely negative by dip-stick assays.
Serum galactose determination with centrifugal analyzers.
Authors: Gabrielli M 
Published: January 2020

Abstract
I describe a rapid quantitative centrifugal analysis for galactose in blood. The technique involves galactose dehydrogenase. As compared to the manual (o-toluidine) method for galactose determination, analysis time (4 min 45 s on the GEMSAEC, 4 min 10 s on the CentificCHEM) and sample volume (5 microliter) were considerably reduced. Sample deproteinization is eliminated. A modified commercial kit was also tested. Results by the procedure correlate well with those by the more classical methods and analytical recovery is about 100%. The method is applied to the determination of galactose in intravenous galactose tolerance tests. Results of actual tests are reported.
Determination of 3-methoxy-4-hydroxyphenylpyruvic acid, 3,4-dihydroxyphenylethylene glycol, and 3,4-dihydroxyphenylmandelic acid in urine by mass fragmentography, with use of deuterium-labeled internal standards.
Authors: Muskiet F A , Fremouw-Ottevangers D C , Nagel G T , Wolthers B G , de Vries J A 
Published: January 2020

Abstract
We report the determination of 3-methoxy-4-hydroxyphenylpyruvic acid, 3,4-dihydroxyphenylmandelic acid, and 3,4-dihydroxyphenylethylene glycol in urine, by use of gas chromatography/mass spectrometry in combination with a simple purification method and deuterium-labeled internal standards. Normal excretion values in terms of creatinine, expressed as a function of age, are given, together with results obtained for patients with neuroblastoma, pheochromocytoma, or parkinsonism treated with L-DOPA + peripheral decarboxylase inhibitor, and for a patient receiving dopamine. We were unable to identify 3, 4-dihydroxyphenyllactic acid in urine. The results obtained and their relation to other catecholamine metabolites and catecholamine-precursor metabolites in urine are discussed.
Radioimmunoassay of serum myoglobin: evaluation and modification of a commercial kit and assessment of its usefulness for detecting acute myocardial infarction.
Authors: Kubasik N P , Guiney W , Warren K , D'Souza J P , Sine H E , Brody B B 
Published: January 2020

Abstract
We evaluated a modified procedure for a commercially available myoglobin radioimmunoassay kit (Nuclear Medical Systems). Within-run and run-to-run precision was acceptable. Normal ranges were established and paralelism studies performed. Clinical usefulness was assessed in 100 consecutive patients admitted to our coronary-care facility. The determinations were done daily, along with creatine kinase and its isoenzymes, and lactate dehydrogenase and its isoenzymes. Fifty of the 100 patients ultimately were shown to have had acute myocardial infarction. Myoglobinemia was present in most of the patients with acute myocardial infarction, but information on its presence was less usefull clinically than was detection of creatine kinase isoenzyme MB.
An improved enzyme immunoassay for progesterone in human plasma.
Authors: Joyce B G , Wilson D W , Read G F , Riad-Fahmy R 
Published: January 2020

Abstract
We describe an enzyme immunoassay for progesterone in which we use a progesterone-11alpha-hemisuccinyl-horseradish peroxidase conjugate as the "label" and an antiserum raised in rabbits to a progesterone-11alpha-hemisuccinyl-bovine serum albumin conjugate. In this assay, antibody-bound and free steroid are separated by using a second antibody precipitation procedure. The assay has a lower limit of sensitivity of 10 pg/assay tube and satisfies the usual criteria of specificity, precision, and accuracy. Results obtained with a comparison radioimmunoassay and our procedure agreed well (r = 0.98). Eighty samples can be assayed per day. It is not only well suited for surveys where accurate determination of progesterone concentrations in small plasma aliquots is required, but also for monitoring ovulation induction in patients attending infertility clinics.
An enzymatic radioassay for gentamicin.
Authors: Case R V , Mezei L M 
Published: January 2020

Abstract
An enzymatic, radiochemical assay procedure for measuring serum gentamicin by use of gentamicin 3-acetyl-transferase and [acetyl-14C]acetyl-Coenzyme A is described and evaluated. The enzyme stoichiometrically and quantitatively transfers a radioactive label to the analyte during a 10-min incubation at 37 degrees C. The labeled gentamicin is then absorbed onto phosphocellulose paper discs, which are washed to remove unreacted [acetyl-14C]-acetyl-Coenzyme A and counted in a liquid scintillation counter for 1 min each. The assay detects gentamicin in concentrations as low as 0.2 mg/liter and gives a linear response to concentrations as high as 20 mg/liter. Sisomicin, a structural analog of gentamicin, is measured by the procedure, and tobramycin and netilmicin are slightly reactive. No other interferents were found among other aminoglycosides, other antibiotics, or substances endogenous to serum. Results by the new method are compared to those by radioimmunoassay and a microbiological method.
Atomic absorption spectrophotometry of chromium in serum and urine with a modified Perkin-Elmer 603 atomic absorption spectrophotometer.
Authors: Kayne F J , Komar G , Laboda H , Vanderlinde R E 
Published: January 2020

Abstract
Modification of a Perkin-Elmer 603 atomic absorption spectrophotometer by adding a high-intensity tungsten-halogen lamp for background correction significantly improved the detection limit for elements that have analytical wavelengths in the near-ultraviolet and visible regions. Chromium in human serum and urine can be measured, with a simplified sample-handling technique, in concentrations of less than 0.1 microgram/liter. For comparison, the mean value for chromium in the serum of eight men was 0.14 microgram/liter.
Polystyrene tube immunoradiometric assay for human alpha1-fetoprotein, and its use for mass screening.
Authors: Grenier A , Morissette J , Valet J P , Bélanger L 
Published: January 2020

Abstract
We describe a two-site immunoradiometric assay for human alpha1-fetoprotein, with use of antibody-coated polystyrene tubes as solid phase. The sensitivity, precision, and simplicity of this system make it eminently suitable for mass-screening purposes. We currently use it for neonatal detection of hereditary tyrosinemia in the Province of Quebec; measurements are made on blood spotted and dried on paper. This system could be well suited for other mass surveys, such as prenatal screenings for fetal abnormalities.
The 4-hydroxybenzoate/4-aminophenazone chromogenic system used in the enzymic determination of serum cholesterol.
Authors: Meiattini F , Prencipe L , Bardelli F , Giannini G , Tarli P 
Published: January 2020

Abstract
A single reagent, containing cholesterol oxidase, cholesterol esterase, peroxidase, 4-hydroxybenzoate, and 4-aminophenazone, is used in determining serum cholesterol. Analysis time is 15 min, and the standard curve is linear to 6.0 g/liter. Analytical recovery of cholesterol was 100.1 +/- 0.4%. Within-run precision (CV) was less than or equal to 1.4 1.4%, between-run less than or equal to 4.8%. Comparison with results by a Liebermann Burchard method [Clin. Chim. Acta 5, 637 (1960)] gave a linear regression of y = 1.08x--0.05, with a correlation coefficient (r) of 0.985. Comparison with the Roeschlau enzymic method [J. Clin. Chem. Clin. Biochem, 12, 226 (1974)] gave y = 1.02x + 0.01 (r = 0.958). Comparison with the enzymic method of Allain et al. [Clin. Chem. 20, 470 (1974)] gave y = 1.01x--0.00 (r = 0.995). The following substances do not interfere up to the indicated concentrations (mg/liter): hemoglobin (5000), bilirubin (100), reduced glutathione (150), l-cysteine (400), urea (3000), creatinine (200), uric acid (200), d-glucose (10000), L-ascorbic acid (50), acetylsalicylic acid (500), L-DOPA (10), ergothioneine (1000), 2,5-dihydroxybenzoic acid (20), and 3,4-dihydroxybenzoic acid (10). Stored in an amber-colored bottle, the working reagent is stable for three months at 2--8 degrees C and for three weeks at 25 degrees C.
Anion-exchange chromatography of erythrocytic and muscle adenylate kinase and its effect on the serum creatine kinase isoenzyme assays.
Authors: Klein B , Jeunelot C L 
Published: January 2020

Abstract
We determined the elution profile of erythrocytic and muscle adenylate kinases (EC 2.7.4.3) in the Roche chromatographic creatine kinase procedure and studied the interference these enzymes would cause in the isolation and assay of serum creatine kinase (EC 2.7.3.2) isoenzymes. Both adenylate kinases co-elute with the creatine kinase MM fraction and do not interfere with the isolation or assay of the MB fraction.
Multilayer Film Elements for Clinical Analysis: General Concepts
Authors: Curme Henry G , Columbus Richard S , Dappen Glenn M , Eder Thomas W , Fellows Williams D , Figueras John , Glover Clyde P , Goffe C A , Hill Doyle E , Lawton William H , Muka Edward J , Pinney Jack E , Rand Royden N , Sandford Kari J , Wu Tal W 
Published: January 2020

Abstract
vol. 24
p 1335. In this paper, the equation, p 1340, relating Dt to Dr after integration should read
See Equation in the PDF File
In Table 3, the concentration units are mg/liter, not g/liter, and the day-to-day SD in glucose concentration at 999 mg/liter glucose is 15.1 mg/liter, not 1.51 mg/liter. In Table 4, p 1341, the concentration of Hypaque is expressed in mg iodine/L (mg I/L).
p 1343. Table 3 was inadvertently omitted from this paper. It is as follows.
See Table in the PDF File
The table numbers for Tables 3–6 in the paper as printed should each be increased by one.
p 1627. In Table 6, the numbers in the first line should read 580, 2260, 2210, and +50. The "+50" in the second line should be deleted.
Method for screening urinary steroids by gas chromatography.
Authors: Trocha P , D'Amato N A 
Published: January 2020

Abstract
Numerous methods are available for measuring urinary steroids in evaluating endocrine dysfunctions. Measurements of these particular steroids, or groups of them, usually involve tedious isolation methods, corrections for interferences and losses of the steroid, and (or) expensive reagents. We show how gas-liquid chromatography provides a rapid, sensitive, and direct method for several steroid metabolites in urine. Androstanol, androsterone, etiocholanolone, dehydroisoandrosterone, pregnanediol, pregnanetriol, 11-keto-17-ketosteroids, and the 11beta-hydroxy-17-ketosteroids can be identified and quantified.
Measurement of free and free-plus-peptide hydroxyproline fractions in plasma.
Authors: Husdan H , Leung M , Oreopoulos D , Rapoport A 
Published: January 2020

Abstract
Plasma hydroxyproline fractions--free-plus-peptide and free--were determined by a method involving centrifugal ultrafiltration and the procedure of Kivirikko et al. [Anal. Biochem. 19, 249 (1967)]. Within- and between-day precision (CV) for the combined fractions was 4--5% and 2.8--6%, respectively. Mean analytical recoveries of free hydroxyproline were 95.2% (87--109%) in the normal range, and 97% (91--108%) in the above-normal range. Normal ranges for plasma hydroxyproline fractions, based on data for 11 men and 19 women, were free-plus-peptide, 7.5--25.3; free, 4.9--22.7; and peptide (calculated), 0.1--5.1 mumol of hydroxyproline per litre, respectively. These ranges showed no sex-related differences and were gaussian in distribution. A factor was derived to transform data on concentrations in ultrafiltrate into plasma concentrations.
P-Nitrophenol-alpha-D-glucopyranoside as substrate for measurement of maltase activity in human semen.
Authors: Chapdelaine P , Tremblay R R , Dubé J Y 
Published: January 2020

Abstract
Hitherto, seminal plasma maltase has been measured with maltose as substrate; this method is time consuming and lacks specificity. The use of a synthetic substrate, p-nitrophenol-alpha-D-glucopyranoside, allows accurate and rapid determination of this activity. When maltase is added to the incubation medium (the substrate and reduced glutathione in potassium phosphate buffer, pH 6.8), maintained at 37 degrees C, hydrolysis of the original substrate to p-nitrophenol goes at a constant rate during 4 h. Under optimal conditions of incubation, the Michaelis constant of the reaction, calculated by the Hanes method, was 2.92 +/- 0.84 (SD) X 10(-3) for six different semen samples. Isomaltase appeared to be absent from seminal plasma. The enzyme is stable to freezing and slow thawing and can be stored for at least 26 days at -80 degrees C. Its molecular weight is 259 000. Tris(hydroxymethyl)aminomethane (pH 6.8) exerts a noncompetitive inhibition on the enzyme activity. In 68 men 23 to 45 years old, whose semen analyses were normal, the seminal plasma maltase activity was 467 +/- 135 (SD) mU/g of protein. It was generally decreased in patients with infertility disorders.
Methods compared for determining zinc in serum by flame atomic absorption spectroscopy.
Authors: Kelson J R , Shamberger R J 
Published: January 2020

Abstract
We compared two methods for determination of serum zinc by flame atomic absorption spectroscopy. The first involved 10-fold dilution of serum with water; the second, deproteinization of serum with trichloroacetic acid. Analytical recovery of Zn2+ added to serum averaged 99.3 and 99.9%, respectively, by the two methods, but measured concentrations were consistently greater by the second method [mean difference, 118 +/- 27 (SD) mug/liter]. For the analysis of 55 sera, measured concentrations were also greater by the second method [mean difference, 91 +/- 28 (SD) mug/liter]. We dialyzed serum to remove most of the zinc and measured analytical recovery of increasing amounts of Zn2+ added to this dialyzed serum or, conversely, of zinc in a mixture of increasing volumes of dialyzed serum in a Zn2+ standard. Recovery results for the dilution method showed an interference by an unidentified, but nondialyzable serum component(s). Recovery was not improved by use of (a) a "high-solids" burner, (b) a diluent containing 1-butanol, or (c) a Mn2+ internal standard.
Determination of uric acid on continuous-flow (AutoAnalyzer II and SMA) systems with a uricase/phenol/4-aminophenazone color test.
Authors: Klose S , Stoltz M , Munz E , Portenhauser R 
Published: January 2020

Abstract
This report describes a new specific colorimetric procedure for uric acid assay with AutoAnalyzer II and SMA (Technicon) systems, made specific by the application of uricase. Hydrogen preroxide, formed in this reaction, effects the oxidative coupling of 4-aminophenazone and 2,4-dichlorophenol under the catalytic influence of peroxidase. The red dye formed is measured at 505 or 520 nm. A sample blank measurement is not necessary, and the reagents show very good stability. The test shows linearity up to 714 mumol of uric acid per liter. Results of thie method correlate very well with those by the uricase-ultraviolet and uricase--catalase methods. There is no interference by hemoglobin, bilirubin, lipemia, and various drugs, except a minor interference by alpha-methyldopa. Interference from ascorbate is eliminated by ascorbate oxidase. This method can be regarded as a considerably improved routine test for uric acid on continuous-flow systems in clinical laboratories as compared with the commonly used phosphotungstate method.
A practical radioimmunoassay of thyroglobulin.
Authors: Bodlaender P , Arjonilla J R , Sweat R , Twomey S L 
Published: January 2020

Abstract
We describe a reliable and convenient double-antibody radioimmunoassay for human thyroglobulin that can be performed within two days. Analytical recoveries were quantitative and immunological equivalence between several sources of human thyroglobulin was demonstrated. Cross reactivity with either thyroxine or triiodothyronine was insignificant. The between-day coefficient of variation in the 5--100 mug/liter range was 10%. The range observed for 68 normal individuals was 2--61 microgram/liter.
Radioimmunoassay of alpha-fetoprotein, with special reference to iodination and purification techniques.
Authors: Schiller H S , Kulchinski L , Luthy D A 
Published: January 2020

Abstract
We report a relatively simple and convenient method for iodinating human alpha-fetoprotein and for purifying the 125I-labeled material. The label is incorporated into human alpha-fetoprotein enzymatically by use of lactoperoxidase. Before each assay the labeled material is purified over two successive short columns: Sepharcryl S-200 Superfine and cellulose. This procedure removes both free iodine and "damaged" fetoprotein. With the purified material we developed a sensitive and reliable radioimmunoassay for alpha-fetoprotein in serum and amniotic fluid.
Individual character of variation in time-series studies of healthy people: II. Differences in values for clinical chemical analytes in serum among demographic groups, by age and sex.
Authors: Williams G Z , Widdowson G M , Penton J 
Published: January 2020

Abstract
Assessment of the significance of an observed set of serum chemical values for determining a person's state of health requires comparison with a set of defined reference values. We tested the assumption that a reference group of individuals, categorized by age and sex, gives a narrower range of variation than does a larger mixed population. If this were true, the demographic set would be a more sensitive reference than is the customary "normal range" for interpretation of values occurring in the individual. The ratio, R, of intra-personal to inter-personal (group) standard deviations was similar for defined age/sex classes and the overall group for 16 serum constituents. When the "raw" intra-individual variation (biological plus analytical variation) was adjusted to remove the average analytical component, the resulting R was less than 80 for all constituents except creatine kinase, which indicates that these are all particularly strong "discriminators" of individuality. These results imply the need for individual rather than population-based reference ranges, even if the latter are from persons of similar age and the same sex.