bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma calcium, copper, magnesium, and zinc concentrations in patients with the alcohol withdrawal syndrome.
Authors: Bogden J D , Troiano R A 
Published: January 2020

Abstract
We determined zinc, copper, magnesium, and calcium concentrations by atomic absorption spectrophotometry in the plasma of 30 patients hospitalized for treatment of seizures during a period of alcohol withdrawal. Those patients who developed delirium tremens or a prolonged hallucinatory state had significantly higher plasma copper concentrations (P = 0.026), significantly lower zinc concentrations (P = 0.004), and significantly higher copper/zinc ratios (P = 0.001) than the patients who recovered uneventfully. Zinc deficiency may be one of the factors that contribute to the neurologic complications of alcoholism. A determination of the plasma copper/zinc ratio early in the course of alcohol withdrawal could be of value in indicating which patients have the most substantial underlying disease or metabolic imbalance and therefore may be at greatest risk of developing delirium tremens or prolonged hallucinosis.
Blood intermediary metabolite and insulin concentrations after an overnight fast: reference ranges for adults, and interrelations.
Authors: Foster K J , Alberti K G , Hinks L , Lloyd B , Postle A , Smythe P , Turnell D C , Walton R 
Published: January 2020

Abstract
Concentrations of several metabolites in deproteinized blood and plasma were determined in 100 subjects after an overnight fast, to establish reference ranges. Blood glycerol, nonesterified fatty acids, and ketone body concentrations and the 3-hydroxybutyrate/acetoacetate ratio increased with age while blood alanine concentrations delined. Serum insulin and blood alanine concentrations were also related to weight. No marked sex-related differences were found, although blood glycerol concentration was slightly higher in women. Distribution of all metabolite concentrations was positively skewed, except for glucose, but skewness could be corrected by logarithmic transformation. Skew was particularly marked for blood ketone body concentrations. Concentrations of all metabolites in plasma exceeded those in whole blood, but this was significant for only lactate and pyruvate when concentrations in plasma were compared with calculated concentrations in erythrocyte water.
Use of the vertical rotor to facilitate estrogen and progesterone receptor analysis.
Authors: Hofman L F , Moline C , McGrath G , Barron E J 
Published: January 2020

Abstract
Sucrose density-gradient analysis is one method of identifying specific estrogen and progesterone receptors in mammary tumor tissue. Use of the vertical rotor makes this practical for routine applications in the clinical laboratory by increasing the number of samples that can be run at one time and shortening the centrifuge time from 18 to less than 2 h. The separations and reproducibility compare favorably with those obtained with a swinging-bucket rotor.
Performance comparison of the Corning thin-film agarose and the Hyland thick-film agar methods for immunoelectrophoresis.
Authors: Gerson B , LaBrie J , Copeland B E 
Published: January 2020

Abstract
Many clinical laboratories do immunoelectrophoresis for qualitative assessment of proteins in biological fluids. Commercial kits are available that supply some or all of the necessary components, but the nature of these components varies. Seeking a reliable method for most easily preserving the original immunoelectrophoresis pattern as a permanent record, we compared a thick-film agar method to a thin-film agarose method in immunoelectrophoresis of a total of 70 serum and urine samples. For each sample, either method resulted in the same interpretation. The thin-film agarose method not only yields a stained, permanent record in about the same time that the thick film agar is ready for interpretation but not preservation, but also requires less antiserum, a smaller sample, and may not require purchase of additional hardware.
A further comparison of radioassay results for serum and plasma.
Authors: Kubasik N P , Sine H E 
Published: January 2020

Abstract
We evaluated results for serum vs. plasma for 12 selected radioassay procedures. Blood samples were collected with heparin, oxalate-fluoride, or ethylenediaminetetraacetate as anticoagulant and compared with the corresponding serum samples. In combination with a previous report [Kubasik, N.P., and Sine, H.E., Clin. Chem. 24 137 (1978)] we have now tested a total of 25 different analytes, using 31 manufacturers' kits. Differences were again demonstrated between serum and plasma that may be of sufficient magnitude to alter clinical interpretation of the results. Assays also demonstrated differences based on the procedure used.
Suggested isosbestic wavelength calibration in clinical analyses.
Authors: Hoxter G 
Published: January 2020

Abstract
I recommend the use of isosbestic points for conveniently checking the wavelength scale of spectrophotometers in the ultraviolet and visible regions. Colorimetric pH indicators, hemoglobin derivatives, and other radiation-absorbing substances that are convertible into stable isomers of different absorption spectra provide a means for calibrating many different wavelengths by comparing the absorptivities of these isomers in equimolar solutions. The method requires no special precautions and results are independent of substance concentration and temperature between 4 and 45 degrees C. Isosbestic calibration may be important for (e.g.) coenzyme-dependent dehydrogenase activity determinations and in quality assurance programs.
Radioimmunoassay for chlorpromazine in plasma.
Authors: Midha K K , Loo J C , Hubbard J W , Rowe M L , McGilveray I J 
Published: January 2020

Abstract
A radioimmunoassay for chlorpromazine in plasma is described. The antiserum was obtained by immunizing rabbits with a conjugate of bovine serum albumin and N-(2-carboxyethyl)desmethylchlorpromazine. It is specific for chlorpromazine and its minor active metabolite, N-desmethylchlorpromazine. Other known active or inactive chlorpromazine metabolites and other psychotropic drugs tested do not cross react with the antiserum. Less than 34 pg of the drug can be detected in 200 muL of plasma. As many as 100 samples can be processed in a day by one technician. Concentrations of chlorpromazine can be measured in 200-muL samples of plasma collected as late as 48 h after a single oral 25-mg dose.
Automated enzymatic assay for plasma ammonia.
Authors: Humphries B A , Melnychuk M , Donegan E J , Snee R D 
Published: January 2020

Abstract
An enzymatic method for determining plasma ammonia with the Du Pont Automatic Clinical Analyzer (aca) is described. The assay requires a sample volume of 500 muL for a kinetic ammonia measurement. The reaction is initiated with glutamate dehydrogenase and the rate of depletion of NADPH is monitored with two measurements, 17 s apart, at 340 nm. Reaction conditions have been optimized for maximum sensitivity through both one-factor-at-a-time and multiple variable response surface optimization techniques. Linearity to 1000 mumol of ammonia per liter of plasma has been achieved. No significant interferences were observed from anticoagulants or endogenous blood components, including pyruvate and oxalacetate. Use of the coenzyme NADPH (instead of NADH) in this aca procedure eliminates the lengthy pre-incubation otherwise required for endogenous dehydrogenase reactions.
Relation of creatine kinase isoenzyme MB to postoperative electrocardiographic diagnosis in patients undergoing coronary-artery bypass surgery.
Authors: Roe C R , Wagner G S , Young W G , Curtis S E , Cobb F R , Irvin R G 
Published: January 2020

Abstract
We compared (a) the frequency of detection of isoenzyme MB of creatine kinase (CK; EC 2.7.3.2) in serum of patients undergoing coronary-artery bypass surgery, (b) the interval during uhich its activity was supranormal in serum, and (c) an index of the amount of CK released into blood ("CK-MB area") with postoperative electrocardiographic changes in 80 patients. The frequency of detection of CK-MB is a function of frequency of sampling during the early postoperative period. Because the duration of appearance and the calculated CK-MB area increased as the electrocardiogram became more specific for infarction (p less than 0.01), a twice-daily sampling schedule proved clinically relevant. Only 5.4% of patients had electrocardiographic evidence of infarction when CK-MB was absent by the second postoperative morning. When CK-MB was still detected at that time, 69.6% of patients had persistent new Q waves, consistent with infarction. In three patients who died postoperatively, significant myocardial necrosis was demonstrated. All three had had persistently increased values for CK-MB, related to electrocardiographic changes of infarction in one patient and ischemic changes in two. Evidently CK-MB is a more sensitive indicator of myocardial necrosis than the electrocardiogram and CK-MB area should be a useful criterion in evaluating methods of intra-operative myocardial protection.
Increase in dialyzable calcium associated with therapy with lithium.
Authors: Toffaletti J , McComb R B , Bowers G N 
Published: January 2020

Abstract
We measured total and dialyzable calcium concentrations in consecutive sera submitted for routine lithium analysis. Of 98 samples from 61 different individuals, six (6.1%) total calcium results and 32 (33%) dialyzable calcium results were above the respective reference intervals. By comparison, when both total and dialyzable calcium were measured on 50 different apparently healthy volunteers, no results were outside either reference interval (2.20--2.58 mmol/L for total and 1.30--1.47 mmol/L for dialyzable calcium). These increases were not due to age or sex differences between the patients and controls. From the dialyzable calcium data, there appears to be an even higher incidence of mild hypercalcemia in patients receiving oral lithium salts than is indicated by the total calcium concentration alone.
Comparison of theophylline concentrations in venous blood and capillary blood in asthmatic children.
Authors: Umstead G S , Rosen J P 
Published: January 2020

Abstract
Twenty children, five to 16 years old, diagnosed as having asthma, were studied to compare the serum concentrations of theophylline obtained by standard venipuncture with capillary concentrations obtained by finger lancet. The mean theophylline concentration in venous samples was 9.27 mg/L and in capillary samples was 9.26 mg/L. Comparison by the paired t-test showed no statistical difference between kinds of samples. When surveyed as to their preference, nine patients preferred the venous method, five the capillary method, and six had no preference.
A commercial digoxin radioassay modified for use as an emergency ("stat") procedure.
Authors: Chen I W , Sperling M , Maxon H R 
Published: January 2020

Abstract
A recent "stat" procedure recommended by the manufacturer for use with a commercial digoxin radioassay involves doubling the amount of antibody used in the regular procedure, to compensate for the decrease in binding that results from use of a shorter (10 min) incubation. This has two obvious disadvantages: increased material cost and decreased sensitivity because of the increase in the binding capacity of the assay. In our modified procedure, we kept the binding capacity constant by decreasing the volume of the incubation mixture without increasing the amount of antibody. Total binding and the rate of binding on 10-min incubation are 50.4 and less than 1.3% per minute, respectively. Results by our modified stat procedure compare well with those by the manufacturer's suggested regular procedure in terms of sensitivity, accuracy, and precision, and are more sensitive and economical than those by the manufacturer's suggested stat procedure.
Muscle protein analysis. I. High-resolution two-dimensional electrophoresis of skeletal muscle proteins for analysis of small biopsy samples.
Authors: Giometti C S , Anderson N G , Anderson N L 
Published: January 2020

Abstract
We have been developing a clinically useful method for high-resolution two-dimensional electrophoretic analysis of small (5--10 mg) human muscle biopsy samples with sufficient resolution to resolve the major contractile proteins and enzymes. Using rabbit psoas muscle as a model, we describe methods for sample preparation and two-dimensional electrophoresis. Basic proteins, which appear as streaks when conventional isoelectric focusing is used in the first dimension, are resolved through a modification of the nonequilibrium pH gradient electrophoresis method [Cell 12, 1133 (1977)]. In the two-dimensional patterns obtained from rabbit muscle, we identify the components of 10 enzymes and of myosin, actin, tropomyosin, and troponin. These patterns indicate charge heterogeneity in a large fraction of the proteins. Comparison of rabbit and normal human muscle patterns shows many similarities, but much additional work is required to confirm identifications. We conclude that analysis of small biopsy samples is feasible, but that all aspects of human sample acquisition, storage (when necessary), and preparation require thorough study before the method becomes routine in human muscle research and, ultimately, in the diagnosis of some muscle diseases.
Determination of manganese in whole blood and serum.
Authors: Pleban P A , Pearson K H 
Published: January 2020

Abstract
We describe methods for determination of manganese in whole blood and serum with Zeeman-effect flameless atomic absorption spectroscopy. These analyses are performed on a twofold or fourfold dilution of the specimen in Triton X-100, 1 g/L. No predigestion or extraction procedures are required. The method of standard additions was used for quantitation. Within-run coefficients of variation for whole-blood manganese were 7.0 and 5.5% for 2.29 and 5.67 micrograms/L, respectively. For determination of serum manganese, coefficients of variation were 10.3 and 5.3% for 0.97 and 3.01 micrograms/L, respectively. Manganese detection limits for the assays were 3.0 pg. Whole-blood manganese concentrations, determined for 60 subjects, yielded a mean (+/- SD) of 9.03 (+/- 2.25) micrograms/L. Mean serum manganese concentration, determined for 20 subjects, was 1.82 (+/- 0.64) microgram/L. No correlation was found between blood manganese concentrations and age, sex, or smoking status.
Response-surface co-optimization of reaction conditions in clinical chemical methods.
Authors: Rautela G S , Snee R D , Miller W K 
Published: January 2020

Abstract
We describe the theory and applications of the response-surface approach to simultaneous optimization (co-optimization of multiple interdependent variables. The co-optimization experiments are designed according to a selected response-surface model. Computer-assisted analysis includes fitting the data to the model, testing the resulting fit for statistical validity, and plotting contour maps of the model for simple interpretation. Co-optimizations of the reaction parameters of three methods--creatine kinase, lipase, and aspartate aminotransfrease--are discussed to illustrate the application of the approach. In contrast to the commonly used optimization strategies in which each factor is varied in turn while the others are kept constant, the response-surface approach allows study of several responses (reaction rates, sensitivities) and effects (linear, curvature, interaction) at the same time. It also allows determination of accurate optima, which is necessary for the formulation of analytically reliable clinical methods.
The performance of delta check methods.
Authors: Sheiner L B , Wheeler L A , Moore J K 
Published: January 2020

Abstract
The percentage of mislabeled specimens detected (true-positive rate) and the percentage of correctly labeled specimens misidentified (false-positive rate) were computed for three previously proposed delta check methods and two linear discriminant functions. The true-positive rate was computed from a set of pairs of specimens, each having one member replaced by a member from another pair chosen at random. The relationship between true-positive and false-positive rates was similar among the delta check methods tested, indicating equal performance for all of them over the range of false-positive rate of interest. At a practical false-positive operating rate of about 5%, delta check methods detect only about 50% of mislabeled specimens; even if the actual mislabeling rate is moderate (e.g., 1%), only abot 10% of specimens flagged a by a delta check will actually have been mislabeled.
Is antiglycolysis required for routine glucose analysis?
Authors: Sazama K , Robertson E A , Chesler R A 
Published: January 2020

Abstract
We obtained -68 pairs of simultaneously drawn serum and fluoride-oxalate plasma samples from patients and analyzed them by a continuous-flow (AutoAnalyzer II) glucose oxidase method. Glucose concentrations ranged from 370 to 3530 mg/L. Glucose concentrations for samples obtained in the fluoride-oxalate preservative averaged 42 +/- 35 mg/L (mean +/- SD) higher than serum. The magnitude of this difference was independent of glucose concentration. Linear-regression analysis of 270 pairs for which the time from collection to separation was recorded indicated that the difference between serum and plasma increased by 0.32 mg/L per minute of delay over a time span of 15 to 295 min. These differences are smaller than those described in standard textbooks. We conclude that, with the specimen-handling process used in our hospital, serum glucose determinations are clinically acceptable.
Analysis for underivatized theophylline by gas-chromatography on a silicone stationary phase, SP-2510-DA.
Authors: Schwertner H A 
Published: January 2020

Abstract
I describe a flame-ionization gas-chromatographic method for the quantitative analysis of serum theophylline without the need for derivatization. The analysis is performed isothermally on a new silicone stationary phase, 2% SP 2510-DA (Supelco). With this liquid phase, gas-chromatographic properties and sensitivities are comparable to methods requiring derivatization. A salt-solvent pair of ammonium sulfate and methylene chloride/hexane/acetic acid (80:20:0.1 by vol) is used for extraction. Ammonium sulfate greatly reduces co-extractable interferences from icteric, lipemic, and hemolyzed serum. The density of methylene chloride is adjusted with hexane so that the solvent is less dense than the salt-saturated serum and can be removed by decanting. Acetic acid, used to adjust the pH of the serum samples, is combined with the extraction solvent rather than being added individually to the serum samples. Theophylline values obtained by this method agree closely with those determined by enzyme immunoassay (correlation coefficient, 0.988).
Radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid from human serum, with use of 125I-labeled ligands.
Authors: Mäentausta O , Jänne O 
Published: January 2020

Abstract
We describe a method for radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid in serum. In the method, 125I-labeled bile acid conjugates are used as the tracers along with antibodies raised against individual bile acid-bovine serum albumin conjugates. Antibody-bound and free bile acids were separated by polyethylene glycol precipitation (final concentration, 125 g/L). Before radioimmunoassay, 0.1-mL serum samples were precipitated with nine volumes of ethanol, and portions from the supernate were used in the assays. The lowest measurable amounts of the bile acids, expressed as pmol/tube, were: cholic acid conjugates, 2; chenodeoxycholic acid conjugates, 0.5; and deoxycholic acid conjugates. 2. Analytical recovery of bile acids added to bile acid-free serum ranged from 85 to 110%; intra-assay and inter-assay CVs ranged from 3.2 to 5.3% and from 5.3 to 12.2%, respectively. Concentrations (mean +/- SD) of the bile acid conjugates in serum from apparently healthy women and men (in mumol/L) were: cholic acid conjugates, 0.43 +/- 0.17 (n = 126); chenodeoxycholic acid conjugates, 0.47 +/- 0.23 (n = 111); and deoxycholic acid conjugates, 0.33 +/- 0.11 (n = 96). The values for primary bile acids were greatly increased in patients with various hepatobiliary diseases.
Lactate-to-pyruvate or pyruvate-to-lactate assay for lactate dehydrogenase: a re-examination.
Authors: Howell B F , McCune S , Schaffer R 
Published: January 2020

Abstract
The pyruvate-to-lactate assay for determining lactate dehydrogenase (EC 1.1.1.27) can now yield linearity equal to or better than that obtained by the lactate-to-pyruvate assay. In addition, there are significant advantages to the pyruvate-to-lactate reaction: (a) a greater change in absorbance per unit time, which allows more accurate spectrophotometric readout; (b) lower reactant concentrations are required, which substantially reduces the cost per assay; (c) solid reagents are used to prepare the assay solution; and (d) reagent solutions are more stable. However, impurities present in commercial NADH preparations may substantially affect measured lactated dehydrogenase activities; therefore, a Standard Reference Material for NADH is being developed for issuance by the National Bureau of Standards.
Stability of dilute solutions of gentamicin and tobramycin.
Authors: Josephson L , Houle P , Haggerty M 
Published: January 2020

Abstract
Dilution of sera containing gentamicin or tobramycin in glass containers results in substantial adsorption of the antibiotic to the surface of the container, which can be prevented if acidic or basic solutions are used to dilute such sera. We describe protocols for radioimmunoassays of gentamicin and tobramycin that include solutions and containers that obviate this problem.
Activities of enzymes in plasma should be measured at 37 degrees C.
Authors: Duggan P F 
Published: January 2020

Abstract
There are considerable differences of opinion as to the most desirable temperature at which activities of enzymes in plasma should be measured. Debate centers around 25 degrees C because of its widespread use in physico-chemical measurements, 30 degrees C because of its supposed technical convenience, and 37 degrees because of its physiological significance. There is, however, widespread agreement that the activities of intracellular enzymes, and of enzymes having a natural function in plasma, be measured at 37 degrees C. Perhaps because estimations of the activities of those enzymes in plasma that have leaked from damaged tissues have been subject to almost continuous modifications, temperature has simply become just another variable to take into account. In this article I describe the relevance of a temperature near 37 degrees C to the activities of all enzymes in man, intracellular and extracellular. I conclude that 37 degrees C is to be favored as the temperature for assaying all parameters in human biochemistry affected by temperature. These include not only enzyme activities but also pH, blood-gas equilibria, binding data, and, in fact, all kinetic activities in the body.
Fluoroimmunoassay: present status and key problems.
Authors: Soini E , Hemmilä I 
Published: January 2020

Abstract
Fluorescence immunoassay of biological fluids (for example, blood samples) is discussed. We attempt to chart present methods of assay as well as new possibilities. Different fluorescent probes, their detection limit, and methods for reduction of background are discussed; methods for separating the free and bound fraction are also reviewed. Special consideration is given to the possibilities of enhancing sensitivity by developing both instruments and chemical methods, and in particular to the possibilities inherent in time-resolved fluorometric applications and to the use of metal chelates in this application.