bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas-Chromatographic/Mass-Spectrometric Identification and Quantitation of Tetronic and Deoxytetronic Acids in Urine from Normal Adults and Neonates
Authors: Thompson John A , Markey Sanford P , Fennessey Paul V 
Published: January 2020

Abstract
Gas chromatographic/mass spectrometric/computer analyses of trimethylsilyl derivatives of urine extracts, prepared by an anion-exchange procedure, reveal the presence of several tetronic and deoxytetronic acids. Identifications were confirmed by comparing gas-chromatographic methylene unit values and mass spectrometric characteristics with those of chemically synthesized samples. In addition, several 1,4-lactones corresponding to the acids were detected in small amounts. The acids were measured in groups of adults and neonates by gas chromatographic/computer determination of peak areas and the use of calculated response factors. In urines from adults, 4-deoxythreonic, threonic, and erythronic acids were present in relatively large amounts. 4-Deoxyerythronic and 2-deoxytetronic acids were present in small to moderate amounts; 3-deoxytetronic and 2-methylglyceric acids were only trace constituents. These latter two acids, in addition to 4-deoxyerythronic, were also trace constituents of several urines from neonates but could not be detected in others. Expressed in terms of creatinine excretion, both groups excreted similar amounts of 4-deoxythreonic acid and neonates excreted significantly more 2-deoxytetronic, erythronic, and threonic acids.
Gas-Chromatographic Measurement of Codeine and Norcodeine in Human Plasma
Authors: Brunson Mary K , Nash J Frank 
Published: January 2020

Abstract
A gas-chromatographic method is described for determination of codeine and norcodeine in human plasma. The method is specific, sensitive, and precise. It was developed for use in bioavailability studies of therapeutic doses of codeine sulfate. After ingestion of a 60-mg codeine sulfate tablet, mean peak codeine concentration in plasma was 107 µg/liter at 1.0 hour. No measurable concentration of norcodeine was found in the plasma by this method.
Sex-Related Patterns in the Profiles of Human Urinary Amino Acids
Authors: Dirren Henri , Robinson Arthur B , Pauling Linus 
Published: January 2020

Abstract
The urinary amino acid profiles of 79 young women and 72 young men were studied with an automated high-pressure amino acid analyzer. A nonparametric statistical analysis was applied for detecting profile differences related to sex and other variables. A strong sex-related pattern was confirmed and its power for sex determination was evaluated. For the women, profile differences related to the use of oral contraceptives were also discovered and evaluated. No correlation with the menstrual cycle was detected.
Improved High-Resolution High-Voltage Paper Electrophoresis System for Use in Screening for Aminoacidopathies
Authors: Spiekerman A M , Hetherly Melvin E , Hall Frank F 
Published: January 2020

Abstract
High-voltage paper electrophoresis of small samples of serum and urine at pH 6.0 resolves basic and acidic amino acids and separates them from the neutral amino acids. For separation and identification of the neutral amino acids, the appropriate area of the electrophoretogram is cut out, sewn onto a second sheet of paper, and rerun at pH 1.9. By this method, amino acids are rapidly resolved. It is suited for use with special procedures such as oxidation of biological fluid with performic acid and specific staining for confirmation of amino acid identification.
Use of the Carbon Rod Atomizer for Analysis of Lead in Blood: Three Methods Compared
Authors: Volosin Michael T , Kubasik Norman P , Sine Harrison E 
Published: January 2020

Abstract
Measurement of lead in whole blood by use of the carbon rod atomizer and atomic absorption spectrophotometry was investigated for three methods: (a) a simple dilution (one volume of whole blood to two volumes of surfactant solution; (b) direct analysis of whole blood (no sample preparation); and (c) a standard chelation extraction procedure in which sodium diethyldithiocarbamate and methyl isobutyl ketone (isopropylacetone) are used. Within-run precision data for normal and abovenormal pools favored the Triton dilution method, for which coefficients of variation were less than 5%. Recoveries of added lead ranged from 94-107% for all three methods. We saw no change in the standard curves for any of the procedures on addition of ethylenediaminetetraacetate to samples. The method of additions was necessary to prepare standards of a matrix composition identical to that of the unknowns.
Improved Method for Densitometry of Electrophoretic Lipoprotein Fractions
Authors: McTaggart Wesley G , Dwyer James L 
Published: January 2020

Abstract
We evaluated a method for the densitometric quantitation of the electrophoretic lipoprotein fractions that sets the limit of integration at the beta-lipoprotein peak maximum. Results were compared with the more conventional method of placing the limit of integration in the valley between the beta- and pre-beta-lipoprotein peaks. The criterion of symmetrical beta-lipoprotein peaks imposed by the method was tested, and manual determination of the beta peak maximum was compared to automatic computer analysis. Computer-generated curves simulating increasing overlap of constant shape beta and pre-beta peaks were analyzed by the two methods. The conventional method introduces an error that increases with increasing overlap, but with the present method results agreed with those for completely resolved peaks. The beta peak was best approximated by an isosceles triangle (at least for the electrophoresis technique used in these studies), indicating symmetry of the beta peak. Values for the area under the lipoprotein peaks obtained by manual and computer placement of the integration limits agreed well (r = .892 to .998; SE of estimate = .0264 to .0306). The "beta peak maximum" method of densitometric quantitation avoids the problems associated with partial resolution of the beta- and pre-beta-lipoproteins. It is equally adaptable to either visual placement of the limits of integration or computer analysis.
Theory of Photometric Errors Applied to the Design and Evaluation of a High-Performance Filter Photometer
Authors: Hewitt Thomas E , Pardue Harry L 
Published: January 2020

Abstract
We have applied a comprehensive theory of photometric errors to the design and evaluation of an inexpensive stabilized photometer. The photometer is described in terms of a group of modules, the characteristics of which are described in terms of their effect on specific error coefficients. Procedures described in this paper show how the principles described earlier [Clin. Chem. 20, 1028 (1974)] can be used to optimize the design of new instrumentation or to evaluate the performance of existing instrumentation. Chemical data are included to verify the agreement between predicted and experimental results
Presence of Carotenoids in the Erythrocyte Membranes of Carotenemic and Noncarotenemic Individuals
Authors: Mathews-Roth Micheline M 
Published: January 2020

Abstract
Erythrocytes and erythrocyte membcarotenemic (serum carotene &gt;4.0 mg/liter) and noncarotenemic individuals contain a small amount of carotenoid pigments. The principal pigment isolated from erythrocytes and erythrocyte membranes from carotenemic individuals cochromatographed with, and has an absorption spectrum similar to, authentic beta-carotene. Traces of beta-carotene were also found in the extracts of the erythrocytes and membranes obtained from the noncarotenemic individuals. These pigments were demonstrable only when the erythrocytes were extracted in the presence of an anti-oxidant (pyrogallol). Anti-oxidants should be used in the extraction and saponification process when only small samples are available or when only small amounts of carotenoid pigments are present in the material to be extracted.
Evaluation of the Corning 940 Calcium Titrator for Use with Serum and Urine
Authors: Weissman Earl B , Pragay Desider A , Bishop Charles 
Published: January 2020

Abstract
The Corning 940 Titrator, which measures total calcium concentration by titration with [ethylenebis(oxyethylenenitrilo)]tetraacetic acid, was evaluated for use in a hospital laboratory. Calcium values for patients' sera were about 0.3 mg/dl lower as measured with the Titrator than with the Technicon SMA 12/60 continuous-flow analyzer. A similar bias was evident when the results with the Titrator were compared with those from atomic absorption spectrophotometry. Agreement was better in the low range and worse in the high range. Within-day and between-day coefficients of variation on the Titrator were about 1.5% and 2.5%, respectively. We saw no interference from magnesium, phosphorus, bilirubin, or in the presence of lipemia. At extremely increased hemoglobin concentrations (500 mg/dl), there is a 5% inhibition. Titrator results for patients' urine samples correlated closely (n = 0.999) with those obtained with the SMA 12/60.
The Potential of Phosphorescence Spectrometry in Clinical Chemistry—The New Generation of Instrumentation and Methodology
Authors: O'Donnell C M , Winefordner J D 
Published: January 2020

Abstract
We review recent advances in instrumentation and methodology in phosphorimetry that should facilitate the use of phosphorimetry for clinical analyses and recent phosphorescence studies of interest to the clinical chemist. We indicate recent advances, particularly improvements in instrumentation, novel methodologies, and new chemical processes that result in either an increase in sensitivity or selectivity (or both) of measurement of compounds of clinical importance. The greatest use of phosphorimetry in the clinical laboratory will not be for the analysis of very large numbers of samples for one species via automatic instrumentation, but rather will be for the analysis of those molecular species difficult or impossible to measure by conventional methods (colorimetry, fluorometry, etc.). Although various instrumental and methodological advances are discussed separately here, the most important use of these advances in clinical chemistry will undoubtedly be when two or more of them are combined, for example, in the use of time- or frequency-resolved phosphorimetry for the selective measurement of the phosphorescence resulting with inorganic probes and the appropriate choice of solvent and pH (of course, the instrument could contain an image vidicon detector for rapid determination of the spectrum, the decay curve, or both).
The Impact of Laboratory Error on the Normal Range: A Bayesian Model
Authors: Krause R D , Anand V D , Gruemer H D , Willke T A 
Published: January 2020

Abstract
Interpretation of clinical laboratory results, aside from clinical considerations, is based on the probability of the result being within a given normal range. This probability is influenced by the degree of error inherent in the analytical method. It would be advantageous to assign a more definite probability to the result of the measurement by combining the error distribution of the result around the true value and the distribution of the healthy population that serves as a reference. Bayesian statistics permits the revision of this prior information into a single probability.
Assay of L-Tyrosine in Serum by Amperometric Measurement of Tyrosinase-catalyzed Oxygen Consumption
Authors: Kumar Anand , Christian Gary D 
Published: January 2020

Abstract
A new enzymatic method for rapid direct measurement of serum tyrosine is described, based on the amperometric measurement of the rate of oxygen consumption when tyrosine is oxidized in the presence of the enzyme tyrosinase in a phosphate buffer (0.1 mol/liter, pH 7.4). A Beckman Glucose Analyzer with a Clark electrode is used for the measurement. The procedure does not require removal of serum protein, incubation nor extraction, and results are obtained in less than 1 mm. Results agree closely with those obtained by a fluorometric procedure and with an amino acid analyzer.
Comparison of Results for Morphine Urinalyses by Radioimmunoassay and Thin-Layer Chromatography in a Narcotic Clinic Setting
Authors: Kokoski Robert J , Jain Mishrilal 
Published: January 2020

Abstract
Radioimmunoassay (RIA) and thin-layer chromatography (TLC) were compared for morphine detection in an actual narcotic clinic setting. A choice of urines from all those screened by TLC allowed a critical comparison as to actual use or non-use of narcotic drugs, rather than a sampling at random in which the question of possible false positives or negatives cannot be conclusively answered. Although RIA is more sensitive than TLC, its advantage is apparent only in those cases where urine specimens are difficult to obtain frequently regularly or where the use of morphine is suspected by the positive identification of quinine in urine that was morphine-negative by TLC. In a selected group of negative and positive specimens chosen without conscious bias, the two methods gave consistently similar results, indicating that the modified TLC method provided few or no false positives or negatives if the negatives were from those cases that were not positive anytime up to 3-4 days before urine collection. We conclude that RIA can be of significant value as a supplement to a TLC screening program, without sacrificing the many advantages that TLC has to offer.
Newer Aspects of the Roles of Zinc, Manganese, and Copper in Human Nutrition
Authors: Burch Robert E , Hahn Henry K J , Sullivan James F 
Published: January 2020

Abstract
Advances in knowledge of the trace elements zinc, manganese, and copper are reviewed (151 references), particularly as related to human metabolism and disorders. The literature reviewed, with few exceptions, is that published by December 1973.
Serum Zinc, Iron, and Copper Concentrations during Typhoid Fever in Man: Effect of Chloramphenicol Therapy
Authors: Pekarek Robert S , Kluge R M , DuPont H L , Wannemacher R W , Hornick R B , Bostian K A , Beisel W R 
Published: January 2020

Abstract
In volunteers experimentally infected with Salmonella typhi, serum iron and zinc concentrations became significantly depressed and there was a concomitant rise in serum copper before the onset of overt clinical illness. However, after several days of fever and the initiation of chloramphenicol therapy, serum iron and zinc concentrations significantly increased. Additional studies—in volunteers with typhoid fever treated with chloramphenicol, in a volunteer with typhoid fever receiving cefazolin and gentamicin, and in untreated rhesus monkeys infected with Salmonella typhimurium—provided evidence that the increase in serum iron concentration during the febrile phase was the result of chloramphenicol therapy, whereas the increase in serum zinc concentrations was a disease-related phenomenon. The importance of trace-metal monitoring during infectious disease and chemotherapy is discussed
Retention of Fluoride with Time in Man
Authors: Spencer Herta , Osis Dace , Wiatrowski Emilie 
Published: January 2020

Abstract
Fluoride retention is high during fluoride supplementation and increases with increasing fluoride intake. When large amounts of fluoride were given for several months the retention of fluoride was about the same as in the initial phase of fluoride supplementation, whether the supplemental dose of fluoride was 10, 20, or 45 mg per day. The rapid return of the fluoride balance to control values after the high fluoride intake was discontinued indicates that there is not only a tendency for continued retention of fluoride during the high fluoride intake but also after large amounts of fluoride have already been retained.
Determination of Serum Copper by Atomic Absorption, with Use of the Graphite Cuvette
Authors: Evenson Merle A , Warren Brenda L 
Published: January 2020

Abstract
We have established and evaluated a flameless graphite cuvette method for copper in serum. This atomic absorption method provides substantial improvement in sensitivity, adequate accuracy, and acceptable precision, and little sample preparation is required before the analysis. Standard addition studies and measurements of National Bureau of Standards materials indicated that the proposed method is accurate, but that sample pH must be kept between 2 and 3 for high accuracy. Cations and anions that frequently are present in proteincontaining samples do not interfere significantly. Sample cross contamination in the syringe must be carefully avoided. Finally, when results for more than 100 patients' sera by this method were compared to those obtained by flame atomic absorption for the same samples, no substantial bias or inaccuracies could be attributed to this new micro-scale method for serum copper. Hence, this method is ideally suited for use on pediatric patients.
Linear Working Graphs in Blood Lead Determinations with the Beckman Flameless Atomic Absorption Cuvet
Authors: Kilroe-Smith T A 
Published: January 2020

Abstract
Working graphs are generally nonlinear when the longitudinal flameless atomic absorption cuvet is used. Such nonlinear curves make it difficult to determine the amount of lead in blood by the method of additions, because of inaccuracies in extrapolating the graph to zero absorbance. This paper describes a method for obtaining linear graphs by making use of opacity (the reciprocal of transmittance, or antilog of the absorbance) instead of absorbance. Because no deuterium arc background corrector is available for the Beckman Model 444, background was corrected by reading the opacity at a nonabsorbing line, 287.3 nm, and subtracting the opacities. A separate reagent-blank correction for lead must also be made.
Comparison of Radioimmunoassay with Thin-Layer Chromatographic and Gas—Liquid Chromatographic Methods of Barbiturate Detection in Human Urine
Authors: Roerig David L , Lewand Donna L , Mueller Marilyn A , Wang Richard I H 
Published: January 2020

Abstract
A radioimmunoassay (I) for barbiturates was compared with thin-layer chromatographic (II) and gas—liquid chromatographic (III) methods for barbiturate detection in human urine. Timed urine samples were obtained from volunteers who had ingested 100 mg of a barbiturate. I detected barbiturate in all urines tested up to 76 h after the dose, and III in all up to 52 h and in 90% up to 76 h. II detected barbiturates in 90% of all urine samples for only 30 h, after which its reliability declined. Glutethimide interfered with radioimmunoassay of barbiturate, producing false positives. I is sensitive, reliable, and fast, and lends itself to screening large numbers of urine samples for barbiturates. For routine urine surveillance, however, we found I to be less useful than II, which is still the method of choice. I has, however, proved to be an excellent method for confirming resuits of II.
Automated Determination of Serum Ceruloplasmin Activity with o-Dianisidine Dihydrochloride as Substrate
Authors: Schosinsky Karl H , Lehmann Peter , Beeler Myrton F 
Published: January 2020

Abstract
An automated method for the enzymatic determination of ceruloplasmin with o-dianisidine dihydrochioride as substrate is described. The method enables the measurement of 30 samples per hour with a coefficient of variation (day-to-day) of 2.8%. Results correlate well (r = 0.99) with those obtained by the corresponding manual method.
The Scope of Mass Spectrometry in Clinical Chemistry
Authors: Lawson Alexander M 
Published: January 2020

Abstract
Several aspects of mass spectrometry and gas chromatography—mass spectrometry are reviewed, including ionization methods, repetitive scanning, selected ion monitoring, and stable isotope measurement. I discuss the application of these and other mass spectrometry methods to the investigation of compound classes relevant to clinical chemistry, to the assessment of inborn errors of metabolism, and to clinical studies. The latter include consideration of volatiles in body fluids, respiration and blood gases, stable-isotope applications, clinical toxicology, and drugs.
Citrate Synthesis by Lymphocytes
Authors: Dixit Padmakar K , Cadwell Ruth 
Published: January 2020

Abstract
The important role of lymphocytes in humoral and cellmediated immunity indicates that they need a readily available intracellular source of energy. Here, we demonstrate that these cells contain enzymes involved in citrate formation. The citrate is oxidized through the tricarboxylic acid cycle to furnish energy. A newly devised, simple radiometric method was used to determine the condensation of labeled acetate or acetyl CoA with oxaloacetate to form citrate. The de novo synthesized citrate was oxidized to pentabromoacetone, and radioactivity of the resulting CO2 was directly related to the amount of citrate synthesized. Both lymphocytes from chronic lymphatic leukemia patients and cultured lymphoblasts possess this active citrate-synthesizing apparatus, although the lymphoblasts appeared to have a considerably higher activity, perhaps because they are larger.
Computer-Controlled Automation of Radioimmunoassay Based on Gel Entrapment of Antibody
Authors: Cottrell David B , Toren E Clifford , Magnuson Judith A , Updike Stuart J 
Published: January 2020

Abstract
We describe a new, broadly applicable approach to radioimmunoassay. Solid-phase binding reagent is prepared by entrapping antibody in polyacrylamide gel. This gel is then fragmented, sieved, and dehydrated in 95% ethanol. Upon evaporation of the ethanol, the dry antibody—gel particles are dispensed into miniature disposable plastic columns. A unidirectional flowing stream configuration is used to construct a standard curve for the polypeptide hormone, angiotensin I, used here to exemplify the technique. Good reproducibility of this standard curve is demonstrated. The analytical system includes a computer-controlled sample turntable, digital pipet, and liquid-switching assembly.
Comparison of Five Radioimmunoassays and Enzyme Bioassay for Measurement of Digoxin in Blood
Authors: MacKinney Archie A , Burnett George H , Conklin Robert L , Wasson Gertrude W 
Published: January 2020

Abstract
Digoxin-containing sera from 86 patients were analyzed for this drug by bioassay and radioimmunoassay. Each serum was analyzed in duplicate by six procedures: inhibition of Na+-K+-dependent ATPase and five "kit" radioimmunoassays from four different commercial sources. Mean values for two of the radioimmunoassays differed significantly from those for the bioassay. One radioimmunoassay mean value was significantly different from the other five mean values. We conclude that normal values for digoxin radioimmunoassay should be determined for each kit, and should not be adopted from published data.
Enzyme Activities of NADPH-Forming Metabolic Pathways in Normal and Leukemic Leukocytes
Authors: Belfiore Francesco , Borzi Vito , Lo Vecchio Luigi , Napoli Elena , Rabuazzo Agata M 
Published: January 2020

Abstract
With respect to the enzymes of NADPH-forming metabolic pathways in human leukocytes: (a) Glucose-6phosphate dehydrogenase and phosphogluconate dehydrogenase (decarboxylating) were less active in leukocytes (mostly myeloblasts) from eight patients with acute myeloblastic leukemia (I) than in leukocytes (mostly granulocytes) from 16 normal subjects (II) or 16 patients with chronic myelocytic leukemia (III). (b) Of the enzymes of the citrate cleavage pathway, ATP citrate lyase and malate dehydrogenase (decarboxylating) (NADP+) were virtually absent in the cells studied. (c) Isocitrate dehydrogenase (NADP+), aspartate aminotransferase, and alanine aminotransferase, which, together with the much more active malate dehydrogenase, constitute a newly proposed NADPH-forming metabolic cycle, showed a higher activity in I than in II or III, and therefore could compensate, as concerns NADPHgeneration, for the low activity of pentose cycle dehydrogenases. We are not sure whether the enzymatic characteristic of I cells is attributable to their immaturity or to their leukemic nature.