bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated Sequential Degradation of Ribonucleic Acids
Authors: Uziel Mayo , Starken J W , Eveleigh J W , Johnson W F 
Published: January 2020

Abstract
An instrument has been constructed that can automatically and selectively remove the terminal nucleotide residue from a ribonucleic acid. The instrument is designed to repeat the degradation cycle. This process involves two steps: (1) The base and sugar fragments are removed by the combined action of periodate and amine. (2) The phosphate residue, attached to the originally penultimate residue, is removed by enzymatic hydrolysis. Various techniques have been studied to establish the optimal methods for separating the residual polynucleotide chain from the various reagents and reaction products. In the most efficient and reproducible system, a membrane is used to separate the residual polynucleotide from the reaction products. The enzyme is bound in an active state to a plastic bead, so that simple filtration separates it from the dephosphorylated polynucleotide. All of the chemical and separation steps are quantitative (greater than 99% yield). The analyses are performed automatically by sampling the diffusate, and they are complete before the enzyme hydrolysis begins. The overall efficiency (number of cycles successfully completed) depends upon the stability of the instrument. We have performed up to six cycles with an average yield of 98%.
Rapid Liquid-Chromatographic Separation of Steroids on Columns Heavily Loaded with Stationary Phase
Authors: Karger Barry L , Berry Laverne V 
Published: January 2020

Abstract
Properties of heavily loaded columns are illustrated, especially as applied to steroid separation. By "heavily loaded" we mean that the column contains an amount of stationary phase such that the pores of the solid support are essentially filled. The solid support can be loaded with as much as 35-50% by weight of stationary liquid phase, depending on the pore volume and the activity of the solid support. Using heptane/dioxane/formamide, we studied several heavily loaded columns with different liquid loadings and solid support particles of various diameters. Porasil C (10-25 µm particle size) gave markedly improved speed and efficiency characteristics over Porasil A (44-53 µm). A separation efficiency as great as 2.5 effective plates per second was achieved with support material having the smaller particle diameter. Qualitative reasons for this good efficiency are discussed. Column efficiency was independent of quantity (from 1 µg to 1 mg) of injected steroid sample. Finally, applicability of heavily loaded columns to separation of steroids is illustrated. With stepwise pressure programming, 10 steroids can be separated in 35 min.
Ultraviolet-Absorbing Compounds in Urine from Patients with Hereditary Disorders of Purine and Pyrimidine Metabolism
Authors: Beardmore Thomas D , Kelley William N 
Published: January 2020

Abstract
A Mark II prototype uv analyzer was used to study urinary uv-absorbing compounds in eight patients with gout, one patient with partial deficiency of adenine phosphoribosyltransferase, three patients with the Lesch— Nyhan syndrome, two patients with hereditary orotic aciduria, and two obligate heterozygotes for orotic aciduria. All eight gouty subjects excreted abnormal amounts of one or more uv-absorbing compounds while on a strictly defined dietary and drug program. These included increased excretion of xanthine, pseudouridine, uracil, or orotidine. The excretion of uv-absorbing compounds in patients with well-defined inborn errors of purine and pyrimidine metabolism was consistent with the findings previously reported. The significance of these abnormalities is discussed and the importance of strictly controlled conditions is emphasized.
Effects of Irradiation or Traumatic Injuries on Propionate Metabolism in Rats
Authors: Henderson Thomas R , Jones Robert K 
Published: January 2020

Abstract
The rate of 14CO2 production in vivo by rats after injection with 10 µCi of 1-14C-propionate is useful in selecting uniform groups of animals for studies of experimental injuries and in investigating dose—response relationships in animals exposed to injury. The response appeared to be most sensitive to lung injury induced by air-blast, but was also sensitive to critical levels of irradiation or thermal exposure. Irradiation with 60Co γ-irradiation significantly depressed 14CO2 production, the degree and persistence being doserelated. Critical burn injuries resulted in decreased rates of 14CO2 production, which decreased as the clinical condition of animals deteriorated. Because the most significant decrease occurred within the first 30 min, measurement of the initial rate of 14C-propionate utilization was sufficient to detect altered metabolic states. High-resolution radioanalyses of urinary organic acids show the major ones excreted to be propionate and its immediate catabolites, methylmalonate and succinate, in both control animals and animals exposed to experimental injuries. These results suggest that propionate metabolism may be one of the sites in intermediary metabolism that is sensitive to alteration by experimental injuries and thus may be one of the more sensitive metabolic indicators.
Extra Lactate Dehydrogenase Isoenzyme Band in Serum of Patients with Severe Liver Disease
Authors: Lubrano T , Dietz A A , Rubinstein H M 
Published: January 2020

Abstract
In a study of lactate dehydrogenase isoenzyme patterns in the sera of patients with severe liver disease, who were primarily selected because of an abnormally high serum bilirubin, 42 of 76 patients had an additional band (LDH-T) between isoenzymes 4 and 5 on acrylamide gel. Thirty of the 42 patients died during followup, 24 within a month of recognition of the extra band.
Paper-Chromatographic Quantitation of 4-Hydroxy-3-methoxymandelic Acid (VMA) in Urine
Authors: Vahidi Ardeshir , Roberts Henry R , San Filippo Joseph , Sankar D V Siva 
Published: January 2020

Abstract
We describe a quantitative paper-chromatographic method for assaying 3-methoxy-4-hydroxymandelic acid (VMA) in urine. VMA is extracted from acidified urine into ethyl acetate, separated from interfering amine, acid, and alcoholic metabolites by paper chromatography, and reacted with diazotized p-nitroaniline. The colored derivative is eluted and spectrophotometrically analyzed. Recoveries of replicates of standard and sample solutions on the same chromatogram exceeded 95%.
Coulometric Titration of Blood Glutathione
Authors: Ladenson Jack H , Purdy William C 
Published: January 2020

Abstract
Conditions are described for coulometric titration of reduced glutathione with silver(I), in an ammoniacal medium. pH and buffer capacity of the medium are important variables. Metaphosphoric acid, 50 g/liter, is superior to metaphosphoric acid, 10 g/liter, or sulfosalicylic acid, 25 g/liter, for precipitating blood proteins. Results of the coulometric method are about the same as those obtained with spectrophotometric procedures in which alloxan or 5,5'-dithio-bis-(2-nitrobenzoic acid) is used.
Automated Immunochemical Procedures for Measurement of Immunoglobulins IgG, IgA, and IgM in Human Serum
Authors: Killingsworth L M , Savory John 
Published: January 2020

Abstract
Automated continuous-flow procedures have been developed for microdetermination of immunoglobulins IgG, IgA, and IgM in human serum. The three immunoglobulins are measured by reactions with specific commercial antiserum, and standardized by use of pooled human serum containing known concentrations of IgG, IgA, and IgM. Values determined for the immunoglobulins by the automated procedures correlate with values obtained by radial immunodiffusion. The precision of replicate determinations for the IgG, IgA, and IgM methods is 3.64, 5.11, and 6.00% (CV), respectively.
Plasma Calcium Assay, with Use of the Jellyfish Protein, Aequorin, as a Reagent
Authors: Izutsu K T , Felton S P 
Published: January 2020

Abstract
A previously proposed assay for plasma calcium, suitable for routine clinical measurements, has been investigated. The method is based on the calcium-sensitive luminescence of a jellyfish protein, aequorin. Advantages of this method are low cost, simplicity, and the suitability of most currently available fluorometers and spectrophotometers for the assay. Disadvantages are that aequorin may not be readily available, and that the assay apparently yields only the total and (with suitable sample preparation) the diffusible calcium concentrations.
Use of the Du Pont "Automatic Clinical Analyzer" in Direct Determination of Lactic Acid in Plasma Stabilized with Sodium Fluoride
Authors: Westgard James O , Lahmeyer Brenda L , Birnbaum Marvin L 
Published: January 2020

Abstract
We have studied the determination of lactic acid with the Du Pont ACA and the suitability of plasma as a sample. Blood collected in sodium fluoride/ potassium oxalate Vacutainers and separated in 15 min provided acceptably stable plasma. With a 40-µl sample of plasma, results are linearly related to concentration to 20 mmol/ liter. Standard deviations were 0.16-0.22 mmol/ liter for day-to-day precision. When lactate was added to 53 samples, an average of 99.11% was recovered analytically. Results for plasma lactate (y-axis) agreed with those on plasma filtrates by the Calbiochem "Rapid Lactate" method (n, 92; slope, 1.025; y intercept, -0.086 mmol/liter; standard error, 0.23 mmol/liter). Perchloric acid filtrates can also be analyzed, but fluoride-stabilized plasma is simpler to use.
Gas-Liquid Chromatographic Isolation, Identification, and Quantitation of Some Barbiturates, Glutethimide, and Diphenylhydantoin in Whole Blood
Authors: Cooper Rodney G , Greaves Mavis S , Owen Goronwy 
Published: January 2020

Abstract
An accurate method is described for the qualitative and quantitative determination of 11 barbiturates, glutethimide, and diphenylhydantoin in a single extract obtained from 1 ml of whole blood, which is extracted with ether at pH 2 and separately but simultaneously gas-liquid chromatographed on a selective (3% OV-17) and a nonselective (5% OV-1) column. Retention data are given. Results for barbiturate obtained by the Broughton [Biochem. J.63, 207 (1956)] spectrophotometric method and this gas-liquid chromatographic method are compared. Blood from more than 30 patients has been analyzed, and data are given to illustrate some of the findings.
Comparison of Rapid Clottable Fibrinogen Assays
Authors: Davey Frederick R , Carrington Constance E , Nelson Douglas A 
Published: January 2020

Abstract
Measurements of fibrinogen concentration by use of two rapid methods (clot-weight method and thrombin-turbidity method) were compared with the reference thrombin-coagulation method of Ratnoff and Menzie [J. Lab. Clin. Med. 37, 316 (1951)]. Both rapid methods gave results (in the high, middle, and low ranges) that correlated well with those of the thrombin-coagulation method. However, the thrombin-turbidity method was more precise, easier, and quicker than the clot-weight method.
Investigation of the Use of Calcein in the Ultramicro Fluorometric Determination of Calcium in Serum
Authors: Bandrowski James F , Benson Carl L 
Published: January 2020

Abstract
Calcium in serum is commonly determined fluorometrically with calcium-calcein as the fluorescent complex. A method is presented for analyzing calcein to determine the optimal concentration for both greatest linearity and greatest reproducibility. Serum calcium as determined with the "UNOPETTE" system is compared with results obtained by use of a Technicon SMA 12/60.
Significance of Increased Alkaline Phosphatase and Lactate Dehydrogenase Activities Coincident with Normal Serum Bilirubin
Authors: Betro M G 
Published: January 2020

Abstract
The diagnostic significance of a simultaneous increase in the activities in serum of alkaline phosphatase (ALP) and lactate dehydrogenase (LD) with normal serum bilirubin has been studied in 202 hospital patients. Of these cases, 28% were due to congestive heart failure or myocardial infarction, 25% to malignancy, and 16% to various hepatobiliary disorders. Fewer cases were due to bone fractures with large hematomas, pulmonary embolism, renal failure, or malabsorption syndrome. These biochemical changes in the patients with malignancies did not necessarily signify the presence of hepatic or bony metastases. Hypercalcemia occurred only in this group of patients, and was thus of considerable diagnostic importance. Neither the other tests performed with the SMA 12/60 or the ratios between LD and ALP gave diagnostically useful results.
Modified "Calcium Base Reagent" for Simultaneous Determination of Serum Calcium and Inorganic Phosphate with the "AutoAnalyzer"
Authors: Fischl J , Schwartz F 
Published: January 2020

Abstract
Replacement of the original "calcium base reagent" containing diethylamine with one containing triethanolamine and ammonia in the simultaneous calcium/phosphate method (Technicon method file N-26/a) gives a better calibration curve up to Ca concentrations of 150 mg/liter. In the original method the curve flattens above 100 mg/liter; thus in the proposed modification the reliability of the results are improved for samples from hypercalcemic cases.
Serum Alkaline Phosphatase: Total Activity and Isoenzyme Determinations Made by Use of the Centrifugal Fast Analyzer
Authors: Statland Bernard E , Nishi H Harold , Young D S 
Published: January 2020

Abstract
We present a kinetic method in which the centrifugal analyzer is used to determine total alkaline phosphatase activity and to measure the isoenzymes in bone, liver, and the L-phenylalanine-sensitive fraction (intestine, tumor, and placenta). Measurements were made at 30°C in diethanolamine buffer, with p-nitrophenylphosphate as substrate. The alkaline phosphatase isoenzymes were separated and measured by selective chemical inhibition with 10 mmol/liter L-phenylalanine and 3.3 mol urea per liter. Analyses were performed on sera of a group of healthy pediatric and young adult volunteers and, in addition, on sera from patients with clinically documented osteoblastic disorders and hepatobiliary diseases. The precision and accuracy of the centrifugal analyzer were evaluated, as was the suitability of the instrument for routine clinical laboratory use.
Possible Mechanisms for the Increase in Alkaline Phosphatase Activity of Lyophilized Control Material
Authors: Smith Alistair F , Fogg Barbara A 
Published: January 2020

Abstract
The increased alkaline phosphatase (EC 3.1.3.1) activity of reconstituted lyophilized control sera has recently been the focus of considerable interest because of its possible implications for quality-control procedures. We confirm that these reconstituted materials show a temperature-dependent increase in alkaline phosphatase activity, but could show no alteration in activity of fresh sera. The rate of increase in activity was unaffected by dialysis of the reconstituted material, and occurred more rapidly in dilute solutions. Studies with acrylamide gel electrophoresis and Sephadex G-200 gel filtration showed that, immediately after reconstitution, a high-molecular-weight alkaline phosphatase component predominated; during subsequent spontaneous activation this component decreased, and there was a concomitant increase in a low-molecular-weight alkaline phosphatase component. The results obtained when the reconstituted material was extracted with butanol suggest that the observed changes in alkaline phosphatase activity may be attributed to the breakdown of a complex between alkaline phosphatase and lipoprotein.
Immunochemical Quantitation of Prostatic Phosphatase
Authors: Milisauskas and Vita , Rose Noel R 
Published: January 2020

Abstract
A monkey antiserum to a fraction of human urine precipitated by concentrations of ammonium sulfate between 1.5 and 2.5 mol/liter was shown to contain antibodies specific for prostatic acid phosphatase. Using a modification of Laurell’s immunodiffusion method with a phosphatase stain, we devised a quantitative immunoassay for this enzyme.
Diagnostic Effectiveness of Electrophoresis and Specific Protein Assays, Evaluated by Discriminate Analysis
Authors: Werner Mario , Brooks Samuel H , Cohnen Georg 
Published: January 2020

Abstract
With use of the serum protein pattern as a model, we compared the "Diagnostic Effectiveness" of tests of different chemical specificity—i.e., the percentage classified correctly according to the clinical diagnosis. When results obtained from a selected population of subjects with selected diseases were evaluated by multivariate analysis, disease discrimination by paper electrophoresis, which resolves only chemically heterogeneous fractions, was similar to that of a battery of specific assays for individual proteins.
Gas-Chromatographic Determination of Total Estriol in Amniotic Fluid
Authors: Touchstone Joseph C , Murawec Taras , Bolognese Ronald J 
Published: January 2020

Abstract
A simple gas-chromatographic procedure is described for determination of total estriol in amniotic fluid. Before 20 weeks gestation the concentrations (&lt;1 µg/100 ml) were not meaningful. After 20 weeks there was a gradual rise, followed by a rapid rise during the last weeks of pregnancy.
Separation and Identification of Neutral and Acidic Metabolites in Cerebrospinal Fluid
Authors: Waterbury L D , Pearce L A 
Published: January 2020

Abstract
We describe a method for obtaining profiles of neutral and acidic substances present in human cerebrospinal fluid (CSF) by gas—liquid chromatography. Metabolites extracted with ethyl acetate and ether are converted to methyl ester, trimethylsilyl ether derivatives. With this technique, acidic metabolites of brain amines, and neutral metabolites of dopamine and norepinephrine have been identified in human CSF. Some of these substances have not been reported previously in CSF. Extracted substances are identified on the basis of their methylene-unit values and mass spectral data. Potential use of this method in neurodiagnosis and in delineating drug-induced changes in CSF metabolites is discussed.
Intracellular Clinical Chemistry
Authors: Baron D N 
Published: January 2020

Abstract
The plasma compartment, on which almost all routine analyses in clinical chemistry are performed, occupies only a small part of the body, most of which consists of cells. For most components the intracellular and extracellular compartments have a different composition in health, and change differently in disease. The readily available cells are erythrocytes, and although these can be used for many purposes, including vitamin studies, they should not be used for studies of water and electrolytes. Muscle cells and leukocytes are the other available cells: they present different problems of isolation and methodology, but valid work has been done on their use for studies of water, electrolytes, and pH in health and disease. A recently developing study is the identification of inborn errors of metabolism by analysis of leukocytes and other cells. All cellular studies offer problems in that changes in one type of cell cannot necessarily be applied to changes in the cellular compartment of the body as a whole.
Simple Fluorometric Method for Estimating Practolol [1-(4-Aminophenoxy)-3-isopropylaminopropan-2-ol] in Blood and Urine
Authors: Bodem Gunter , Chidsey Charles A 
Published: January 2020

Abstract
A fluorometric method has been devised for determining practolol [1-(4-aminophenoxy)-3-isopropylaminopropan-2-ol], a new beta-adrenergic receptor antagonist, in blood and urine. The conjugate of deacetylated practolol with nitrosonaphthol is highly fluorescent in weak acid. The excitation wavelength used is 460 nm, the emission wavelength 550 nm.
Alkaline Phosphatase: Lability in Fresh and Frozen Human Serum and in Lyophilized Control Material
Authors: Massion Charles G , Frankenfeld Jean Kingsbury 
Published: January 2020

Abstract
On storage, the activity of alkaline phosphatase (AP) in human serum increases. This has been known, but largely ignored, for 40 years. Improved instrumentation makes this lability more obvious and more important because errors from other sources have been decreased. With a stabilized spectrophotometer we quantitated the effects of time and temperature on AP activity of human sera and of lyophilized "control" material. Activities of 10 fresh sera increased by an average of 0.9, 2.7, and 6.1% in 6, 24, and 96 h; that of pooled serum, frozen and thawed, increased about 1% per hour. For 22 lots of reconstituted lyophilized material the increase ranged from 3 to 22% in 6 h. Refrigeration greatly decreased, but room temperature restored, the rates of change. Freezing decreased the activity of some lots, and most had a smaller rate of increase. Generally, the lower the initial activity of a given lot, the greater was the rate of increase. The difference in rate of increase among materials from different sources varied widely. Delay in measurement of serum AP activity is not the only source of potentially serious error; time and temperature variations are also, when lyophilized materials are used.
Automated Sample-Reagent Loader for Use with the GeMSAEC Fast Analyzer
Authors: Burtis C A , Johnson W F , Mailen J C , Attrill J E 
Published: January 2020

Abstract
With a newly developed automated sample-reagent loader, for use with a GeMSAEC Fast Analyzer, a 15-place GeMSAEC transfer disk can be automatically loaded with reagent and samples in 3.25 min; manual loading methods required 15 min. The resulting precision and accuracy is equal to or better than that for manual methods of loading. Sample carryover of the system was decreased, and is about 1%.
Laboratory for Preparation of High-Purity Clinical Chemicals
Authors: Zief Morris , Nesher Alexander G 
Published: January 2020

Abstract
A laboratory is described for the preparation and analysis of high-purity clinical chemicals. The work area is designed to minimize contact of high-purity materials with the main source of contamination, the chemical operator. We discuss the use of a perforated, curved, anodized aluminum membrane that permits completely free access to the work area and describe the general construction of the laboratory. Dust counts under various conditions are reported, and techniques for eliminating contamination delineated.
Radioimmunoassay of Angiotensin I: Comparison of Two Renin Activity Methods and Use for Other Measurements of the Renin System
Authors: Katz Fred H , Smith Judith A 
Published: January 2020

Abstract
Standard curves for radioimmunoassay of angiotensin I vary with the amount of plasma or plasma extract present in the assay samples. Therefore results of all such analyses must be compared with standards processed precisely like the unknowns. Results of renin activity, assayed directly in plasma or plasma extracts, corresponded well, demonstrating the comparability of the two types of methods. We describe simplifications in measuring activity, substrate, and concentration of renin, and emphasize use of the optimum pH for determining action of the enzyme. In addition, we present evidence for the presence of angiotensin I in the circulation, especially after renin secretion is stimulated.
New Procedure for Purifying and Crystallizing Alkaline Phosphatase from Human Intestinal Mucosa
Authors: Narayanan Sheshadri , Appleton Harold D 
Published: January 2020

Abstract
A new procedure is described for extracting, purifying, and crystallizing alkaline phosphatase orthophosphoric monoester phosphohydrolase (EC 3.1.3.1) from human intestinal mucosa. Active enzyme, extracted with trichlorotrifluoroethane, is subsequently purified by chromatography on Sephadex G-200 and DEAE Sephadex. The acetone and ammonium sulfate precipitation steps that are part of the conventional butanol extraction and purification procedure are eliminated. Enzyme activity is concentrated at each stage of the purification procedure, yielding a preparation with a specific activity three times greater than that obtained with the conventional butanol procedure.