bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Simplified Method for Automated Phosphorus Analysis of Serum and Urine
Authors: Yee Hugh Y , Blackwell LeiLani 
Published: January 2020

Abstract
A simplified procedure utilizing ferrous ammonium sulfate-thiourea as the reductant for the determination of inorganic phosphate in serum and urine by the AutoAnalyzer is described. Elimination of the heating bath usually required for many phosphorus methods for color development yields an improved S.D. of ± 0.25 and facilitates troubleshooting during any apparatus malfunction. Comparison of results between the proposed method and that of Fiske and SubbaRow (1) is presented. Recoveries of added phosphorous in serum or urine are quantitative.
A Comparative Study of Three Methods Measuring Prothrombin Time
Authors: Gudaitis Algird V , Donauer Robert M 
Published: January 2020

Abstract
A comparative study of the Fibrometer, Seratek, and manual technics measuring prothrombin time is described. Three technicians, 3 thromboplastin preparations, and 10 blood specimens with 10 replications were utilized in a 3 x 3 x 10 factorial design. It was found that the reproducibility of each method was subject to an interaction between technician, method, and reagent. In the hands of experienced technicians, the Seratek method was more frequently reproducible than the other two methods. This does not rule out the possibility of the Fibrometer being the method of choice with any particular technician or when less experienced technicians are performing prothrombin time measurements in rotation. The Fibrometer was found to produce the shortest prothrombin time. The importance of considering interaction in comparative or quality control studies consisting of several variables is emphasized.
An Automated Procedure for the Sensitive and Specific Determination of ATP
Authors: Van Dyke K , Stitzel R , McClellan T , Szustkiewicz C 
Published: January 2020

Abstract
An automated procedure is described for the measurement of ATP. This method, based on the linear luminescence response of firefly extracts added to ATP, is rapid, reproducible, and allows a relatively large number of samples to be run (up to 35/hr.). A procedure is also given for the preparation of the luciferin-luciferase system from dried firefly lanterns. Sample volumes required are small, and reading error is about ± 3%. Uniform timing of the addition of reagents and reading of light emission intensity for each sample are insured. Variables investigated include dilution of firefly extract, alterations in time after mixing sample and enzyme, linearity, cation, anion, and ADP and AMP interference.
Urinary Calcium Determination Three Newer Methods Compared with the Clark-Collip Procedure
Authors: King J Stanton , Buchanan Robert 
Published: January 2020

Abstract
A manual titrimetric EDTA-calcium technic, an automated fluorometric EDTA-calcium technic, and the atomic absorption spectrometric technic were compared with the Clark-Collip procedure for determination of urinary calcium. All three were demonstrated to give adequately comparable results. Atomic absorption spectrometry compared best; it also enjoys clear advantages of speed and simplicity.
Two-Dimensional Paper Chromatographic Determination of Amino Acids in Urine
Authors: Spinella Carmine J 
Published: January 2020

Abstract
In an attempt to screen children for amino-aciduria related to various inborn errors of metabolism, a two-dimensional paper chromatography method was developed. This method requires no expensive equipment, resolves a standard mixture of 17 α-amino acids, is consistently reproducible, and requires less than 7 hr from start to visualization of the chromatogram.
A Fluorometric Method for Plasma Cortisol and Transcortin
Authors: Smith E K , Muehlbaecher C A 
Published: January 2020

Abstract
A fluorometric method for cortisol applicable to 0.3-1.0 ml plasma is described. Inclusion of a carbon tetrachloride fractionation step assures greater specificity without undue increase in required technical skill or assay time. Advantages of the fluorometric procedure over the Porter-Silber chromogen method for determination of cortisol-binding globulin (transcortin) by a gel filtration procedure are emphasized. Utilizing the methods described, plasma concentrations of cortisol and transcortin for 22 healthy adults were found to be 13.9 ± 3.9 (SD) µg/100 ml and 15.7 ± 1.3 (SD) µg bound/100 ml, respectively.
The Estimation of Magnesium in Plasma, Muscle and Bone, by Atomic Absorption Spectrophotometry
Authors: Hunt B J 
Published: January 2020

Abstract
The use of the EEL 140 atomic absorption spectrophotometer for the determination of magnesium in plasma, skeletal muscle, and bone is described together with an examination of the pattern of chemical interference in each type of sample. The sampling procedure and preparation of each kind of sample for analysis is detailed, and recovery studies on plasma bone and muscle are presented. The mean value for plasma magnesium in 42 normal men and women was 2.16 mg/100 ml ± SD of 0.08. For 30 male Wistar strain rats, the plasma value was 2.10 mg/100 ml ± SD of 0.18. In 15 normal postmortem human muscle samples, the mean magnesium content was found to be 93 mg/100 g of dry muscle, the series range being between 83 and 101 mg/100 g. The comparable value in 49 male rats was 125 mg/100 g dry weight ± SD 1.8. Bone magnesium in femur diaphysis of 20 male rats (average weight 200 g) was 563 mg/100 g dry weight ± SD 12.7. It is concluded that this instrument, when operated in the manner suggested in our study, is technically easy to use, and gives precise, sensitive, and reproducible results for magnesium in a variety of biologic material.
Automated Micro Measurement of Glucose by Means of o-Toluidine
Authors: Wenk Robert E , Creno Ronald J , Loock Valerie , Henry John Bernard 
Published: January 2020

Abstract
The method described is based on Dubowski’s o-toluidine procedure for the determination of glucose in plasma, serum, or cerebrospinal fluid. It utilizes the rapidity, precision, and closed system of continuous flow analysis of an unmodified AutoAnalyzer to substantially increase sensitivity and accuracy in the low range. The method is more specific than the ferricyanide reduction method. Protein precipitation or dialysis are unnecessary except for hemolyzed specimens and only 0.042 ml of sample are required. The method is inexpensive, easily performed, and compares favorably on a practical basis with enzymatic, reducing, and other aniline dye methods.
An Ultramicromethod for PBI
Authors: Hordynsky W E , King G A , McDonald T A , Murphy W M 
Published: January 2020

Abstract
An ultramicromethod for the determination of PBI which requires only 25 µl of serum is described. The standard deviation of determinations on whole serum is ± 0.24 µg/100 ml. A new delayed ashing technic is described which reduces iodine losses and prevents interference by carbon residues that result from incomplete ashing. Data are presented on 26 infants from which cord blood and infant peripheral blood were obtained at 24-hr. postpartum intervals for PBI analysis. The data indicate that the PBI level in infants reaches a peak at 2 days of age and slowly returns to a normal level at approximately 2 weeks.
The Automated Measurement of Ascorbic Acid in Serum and Urine
Authors: Wilson Sherman S , Guillan Ramon A 
Published: January 2020

Abstract
An automated colorimetric method for determination of ascorbic acid has been developed. This method utilizes diazotized 4-methoxy-2-nitroanaline and produces a stable color. It is suitable for direct measurement of ascorbic acid in serum and urine.
Lipiodol Absorption and Urinary Iodide Excretion as a Screening Test for Steatorrhea
Authors: Amenta Joseph S 
Published: January 2020

Abstract
The Lipiodol absorption test, quantifying urinary iodide concentration 8-12 hr. after ingestion of Lipiodol, is proposed as an effective screening technic for lipid malabsorption. Urinary iodide is converted to free iodine with nitrous acid; the free iodine is extracted into chloroform, producing a characteristic pink color which is quantified photometrically. Under the dosage conditions used, a urinary iodide concentration of less than 0.4 mM/L strongly suggests abnormal absorption of fat. The results of this test have been correlated with fat balance studies in 12 patients with symptoms of intestinal disease and 12 patients asymptomatic for intestinal disease. The screening test was abnormal in all 7 patients with abnormal fat balance studies and in 2 patients with normal fat balance studies. The remaining 15 patients had a normal screening test and normal fat balance studies. No false negatives were found. The simplicity of the test, coupled with its high correlation with the fat balance studies, recommend its use in the clinical laboratory as a valid screening procedure in all patients with suspected steatorrhea.
Fractionation and Quantification of β-Carotene and Vitamin A Derivatives in Human Serum
Authors: Targan Stephan R , Merrill Samuel , Schwabe Arthur D 
Published: January 2020

Abstract
Concentrations of β-carotene, retinyl esters, retinol, retinal, and retinoic acid were determined quantitatively in human serum. Extraction of the compounds was accomplished with a petroleum ether-ethanol system and fractionation by thin-layer chromatography. Each fraction's absorbance was measured by ultraviolet spectrophotometry and expressed as micrograms per 100 ml. By this method, 85% or more of individual premeasured standards and more than 69% of premeasured combined standards could be recovered. The levels of β-carotene and Vitamin A derivatives recovered from the serums of 10 males and 10 females compared favorably with those obtained with other methods. The procedure outlined is rapid, simple, and reproducible.
Evaluation of a New System For the Kinetic Measurement of Serum Alkaline Phosphatase
Authors: Wilkinson J Henry , Boutwell Joseph H , Winsten Seymour 
Published: January 2020

Abstract
Data are presented from the study of a new systematized, kinetic method for the determination of alkaline phosphatase* which was run concurrently in three geographically separated laboratories. The data include estimates of within-day and day-to-day precision, and laboratory-to-laboratory reproducibility. Comparisons are made with three other alkaline phosphatase procedures. An estimated range of normal values is given for adult males and females.
Rapid Single Column Analysis of Amino Acids Related to Some Aminoacidopathies
Authors: Benson James V , Cormick Jean , Patterson James A 
Published: January 2020

Abstract
A single-column procedure, using Type UR-30 resin to develop acidic, neutral, and basic amino acids normally found in protein or peptide hydrolyzates is reported for the study, in human serum, of amino acids associated with some aminoacidopathies. Using a sodium citrate, three-buffer, step-change system, pH 3.28 (0.20 N), pH 4.30 (0.20 N), and pH 6.71 (1.0 N), the acidic and neutral amino acids are chromato-graphed in 85 min. A complete analysis including the basic amino acids requires 135 min. This resin also will perform the function of earlier resins—ie, the separation of the acidic and neutral amino acids by the simple hydrolyzate procedures and by the more complex physiologic procedures.
Non-Urate Chromogens in Body Fluids
Authors: Caraway Wendell T 
Published: January 2020

Abstract
Compounds which interfere in the analytic determination of uric acid are referred to as "non-urate chromogens." Ascorbic acid, when added to serum, causes a significant increase in apparent uric acid levels as determined by a carbonate-phosphotungstate method. The ratio of apparent urate to ascorbic acid is 1:3, a value in close agreement with that obtained for the ratio of labile non-urate chromogens to ascorbic acid in fresh plasma. Ascorbic acid, as well as most of the non-urate chromogens, can be eliminated by mild alkaline treatment prior to adding phosphotungstic acid. These results indicate that the major non-urate chromogen in the average serum is ascorbic acid. The nature of other non-urate chromogens in body fluids is reviewed.
A New Specific Assay for Urinary Creatinine
Authors: Sinha Surendra N , Gabrieli Elemer R 
Published: January 2020

Abstract
A new specific assay for urinary creatinine is described. The procedure is based on the separation of creatinine from other urinary components by Sephadex gel filtration, and subsequent measurement of the compound at 235 nm against a phosphate buffer blank. No interference by other substances has been encountered. The standard deviations in a series of assays using standard solutions are less than 2%, and the recovery of added known amounts of creatinine from urine is excellent. The method has been found satisfactory for simultaneous determination of creatinine and hippuric acid in urine.
Evaluation of Serum Argininosuccinate Lyase (ASAL) Concentrations as an Index to Parenchymal Liver Disease
Authors: Campanini Rafael Z , Tapia Rene A , Sarnat William , Natelson Samuel 
Published: January 2020

Abstract
Serum concentrations of argininosuccinate lyase were determined in 122 patients with primary and secondary diseases of the liver. For comparison, patients with diseases involving other organs of the body were also studied. Extent of liver damage was evaluated by liver biopsy and in some cases, were assessed at autopsy. Daily assays, made during the course of the hospital stay, were correlated with blood concentrations of SGOT, SGPT, LDH, CPK, alkaline phosphatase, bilirubin, total and free cholesterol, and with the thymol turbidity and cephalin flocculation tests, and the albumin to globulin ratio. We tentatively conclude that, compared with these other commonly used tests of liver function, measurement of ASAL is a more specific and sensitive test for disease of the liver parenchyma. The procedure is simple and is readily made routine.
Biochemical Profile of Amniotic Fluid to Assess Fetal Maturity
Authors: Wolf P L , Bloch Daniel , Tsu Tashiko 
Published: January 2020

Abstract
Twelve different biochemical analyses of amniotic fluid were obtained with the AutoAnalyzer to determine the maturity of the fetus in utero. A group of amniotic fluids from patients early in their second trimester and a second group of amniotic fluids collected at term were compared. Uric acid concentration in amniotic fluid was increased significantly at term, and was the only determination we found valuable in predicting fetal maturity. The values for alkaline phosphatase activity in amniotic fluid were too variable to have predictive usefulness.
Turnover of Circulating Enzymes
Authors: Posen Solomon 
Published: January 2020

Abstract
The homeostasis of circulating enzymes is maintained by an equilibrium between the quantity entering the circulation and the quantity removed per unit of time. Enzymes, like most other circulating substances, are removed at a constant fractional rate with characteristic biological half-lives depending on the enzyme, the isoenzyme, and the species involved. Plasma enzyme activities above normal values may result from increased entry, diminished removal, or both. The composition of a mixture of enzymes or isoenzymes may alter after its entry into circulation because of different removal rates for the various components. These factors should be carefully considered before an "enzyme profile" is regarded as indicative of a disease in a particular organ.
Determination of Bilirubin in Amniotic Fluid A New, Simple, and Efficient Method
Authors: Mallikarjuneswara V R , Clemetson C A B , Carr J J 
Published: January 2020

Abstract
A simple, speedy, and efficient method is described for the quantitative determination of unconjugated bilirubin in amniotic fluid. The method makes it possible to use an uncentrifuged sample and to detect as little as 0.00125 mg of bilirubin per 100 ml of amniotic fluid without interference by hemoglobin. The analysis can easily be completed in 30 min. Bilirubin is completely separated from all contaminants, except in samples that are grossly contaminated with meconium. If such interference is absent only one reading, at one wavelength, is necessary; a scanning spectrophotometer is therefore not required.
A Gas Chromatographic Procedure for Detection of Pathological Organic Aciduria
Authors: Hammond K B , Goodman S I 
Published: January 2020

Abstract
A number of nonamino organic acids associated with inborn errors of metabolism can be detected by gas chromatography. The organic acids are extracted into ethyl acetate and diethyl ether, the extracts combined, and the solvents evaporated under nitrogen. The residue is taken up in carbon disulfide and an aliquot chromatographed on 5% neopentyl glycol adipate to separate short-chain fatty acids (C 2 to 6). The remaining carbon disulfide is evaporated, the residue taken up in methanol, and the acids are methylated with diazomethane. The solvent is evaporated, the residue taken up in tetrahydrofuran, and an aliquot chromatographed on 15% diethylene glycol succinate to separate keto, hydroxy, and dicarboxylic acids. Chromatographic patterns for normal and abnormal urines have been established. Four cases of congenital methylmalonic aciduria have been diagnosed by this procedure.
A Membrane Ultrafiltration Procedure for Determining Diffusible Calcium in Serum
Authors: Farese Genevieve , Mager Milton , Blatt William F 
Published: January 2020

Abstract
A rapid, simple procedure is described for separating diffusible from proteinbound serum calcium by centrifugation through high-flux ultrafiltration membranes. The mean normal value for ultrafilterable calcium was 57.1% (range 52 to 61%) of the total serum calcium concentration.
Automated, Simultaneous Microdetermination of Calcium and Magnesium by Atomic Absorption
Authors: Gochman Nathan , Givelber Harry 
Published: January 2020

Abstract
A procedure is described for the simultaneous, automatic determination of serum calcium and magnesium with the AutoAnalyzer, and a dual-channel, double-beam atomic absorption spectrophotometer, the IL Model 153. Advantages over existing procedures include a high rate of analysis (90 samples or 180 tests per hour) and low sample consumption (a total of 30 µl for both determinations). We have compared the new procedure with a manual one in which the Perkin-Elmer Model 303 atomic absorption spectrophotometer is used.
Conventional and Preparative Electrophoretic Separation of Some Urinary Porphyrins and Porphyrin Precursors
Authors: Fischl J , Eichhorn F , Ruttenberg A , Major Ch 
Published: January 2020

Abstract
Urinary porphyrins are concentrated by adsorption on talc, from which they are eluted with ammonium hydroxide. The eluate is electrophoresed on a membrane filter medium in an alkaline buffer (pH 10.5) for 10 to 20 min. Porphobilinogen and δ-aminolevulinic acid in urine are separated within 90 min by "small-volume" electrophoresis in a pH 2.2 buffer.
A Fluorometric Method for Measuring Leucine Aminopeptidase Activity in Red Blood Cells, Serum, or Tissues
Authors: Uete Tetsuo , Tsuchikura Hiroko , Ninomiya Kiichi 
Published: January 2020

Abstract
A fluorometric determination of leucine aminopeptidase activity in a biological system is described, which is simpler and more sensitive than colori-metric methods. Serum or tissue homogenate is incubated with L-β-naphthylamide at pH 7.2 and 37°C for 10 min. After incubation, ethanol is added to stop the reaction and protein is precipitated. The fluorescence of j3-naphthylamine in the supernatant fluid is measured. Since β-naphthylamide reduces the intensity of the fluorescence of s-naphthyl-amine, solutions used in preparing the standard s-naphthylamine curve must have the same concentration of L-leucyl-s-naphthylamide present as in the test sample.
Evaluation of the Purity of Cholesterol Primary Standards
Authors: Williams J H , Kuchmak M , Witter R F 
Published: January 2020

Abstract
Cholesterol preparations recommended for use as primary standards were studied in 1968 (three samples) and 1969 (seven samples). Two lots of one preparation, one studied each year, contained only 97% cholesterol, as shown by gas-liquid chromatography or colorimetry. Three other products studied in 1969 contained oxidized products. Other preparations (two in 1968, three in 1969) were identical as judged by melting point, infrared spectra, qualitative thin-layer and gas-liquid chromatography, and their cholesterol content as determined by gas-liquid chromatography and the Lieberman-Burchard color reaction.
Atomic Absorption Spectrometry of Nickel in Serum, Urine, and Other Biological Materials
Authors: Nomoto Shozo , Sunderman F William 
Published: January 2020

Abstract
An atomic absorption technique is described for analysis of nickel in serum, whole blood, urine, and other biological materials. After the sample has been subjected to protein precipitation or acid digestion, nickel is extracted into methylisobutylketone as a pyrrolidine dithiocarbamate complex, and is measured by atomic absorption spectrometry. The following values (mean ±SD) were obtained for nickel in specimens from healthy subjects living in central Connecticut: serum, 0.26 ± 0.08 , µg/100 ml (N = 40); whole blood, 0.48 ± 0.13 µg/100 ml (N = 17); and urine, 0.23 ± 0.14 µg/100 ml, = 2.4 ± 1.1 µg/day (N = 26). In sera obtained from 36 patients within 24 h after myocardial infarction, the mean nickel concentration was 0.51 ± 0.27 µg/100 ml (p vs. controls = 0.001). In 132 consecutive adult patients, admitted to the hospital for all diagnoses except myocardial infarction, the mean concentration of serum nickel was 0.22 ± 0.11 µg/100 ml. Measurements of serum nickel may prove to be useful in diagnosis of acute myocardial infarction.
Method for Resolving and Measuring Overlapping Chromatographic Peaks by Use of an On-Line Computer with Limited Storage Capacity
Authors: Scott Charles D , Chilcote Dennis D , Pitt W Wilson 
Published: January 2020

Abstract
A simple routine for distinguishing and measuring the positions and areas of overlapping peaks comprising a complex chromatographic "envelope" has been developed for a small on-line computer. The degree of peak overlap is such that no minima and only one maximum occur within the bounds of the envelope. This routine determines corrected initial estimates of the Gaussian parameters of the peaks. The routine is currently being used, in conjunction with a program devised to analyze data generated by a chromatographic system, specifically to evaluate data from high-resolution analyzers.
Simultaneous Multicolumn Liquid/Liquid and Liquid/Solid Chromatography with a Computerized Readout System
Authors: Vestergaard Per 
Published: January 2020

Abstract
For more than a decade, an intense and largely successful effort has been made to automate simple clinical assays. It is clear that second-generation automated methods for the clinical laboratory increasingly must put emphasis on high-resolution methods for the isolation and estimation of individual substances in complex biological mixtures. A multicolumn system has been developed as a general system for high-capacity liquid chromatography from the conviction that such systems will have an increasingly important role to play in clinical chemistry.