bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acid-base-induced changes in the distribution of water between plasma and erythrocytes, as measured with a sodium-ion-selective electrode.
Authors: Fogh-Andersen N , Siggaard-Andersen O 
Published: January 2020

Abstract
aNa+ measured in whole blood changes with the pH of plasma, and the effect depends on the erythrocyte volume fraction (phi E). The relative change in aNa+ with pH, dlnaNa+/dpH, was -0.01 at phi E = 0 and -0.11 at phi E = 0.76. The observations agreed with the combined predicted effects of changes in phi E, in concentration of the NaHCO3 complex, and in liquid-junction potential. The pH-induced osmotic transfer of water between plasma and erythrocytes will affect the concentration of all components confined to plasma. Although the clinical importance of this may be limited, blood samples for research should either be dealt with immediately or stored anaerobically at 4 degrees C until separation, to avoid bias.
A new technique for studying the relationship between maternal diabetes and the sialic acid content of fetal pulmonary surfactant.
Authors: Delahunty T 
Published: January 2020

Abstract
By adapting a standard method for precipitation of high-density lipoprotein cholesterol with phosphotungstic acid (PTA) and Mg2+, fetal pulmonary surfactant can be rapidly isolated from human amniotic fluid, 97% of the total disaturated phosphatidylcholine being precipitated from the sample. The lecithin/sphingomyelin ratio for 17 separate specimens correlated reasonably well (r = 0.76) with the concentration of disaturated phosphatidylcholine in the PTA precipitate. Using thiobarbituric acid as the chromophore, I measured sialic acid in the PTA precipitate after overnight treatment with neuraminidase. The sialic acid/protein ratio for the PTA precipitate was identical to that for the surfactant, as isolated by ultracentrifugation. The concentrations of insulin and C-peptide were significantly greater in specimens of amniotic fluid from mothers with diabetes than from non-diabetic mothers (p less than 0.001). When the specimens were segregated according to a C-peptide cutoff value of 4 micrograms/L, there was a small, significant decrease in PTA-precipitated concentrations of sialic acid in the samples with C-peptide greater than 4 micrograms/L. The results suggest a possible mechanism for the increased incidence of respiratory distress among infants born to diabetic mothers.
An evaluation of kits for measuring thyrotropin in newborns.
Authors: Pierson E A , Therrell B L , Franz S F , Rudenstein A J , Dziuk P E 
Published: January 2020

Abstract
Several commercial radioimmunoassay kits are now marketed specifically for determination of thyrotropin (TSH) from whole-blood specimens collected on filter paper in neonatal screening programs. We have compared five kits in use in such screening programs in the United States. The reagent kits from Becton Dickinson, Neometrics, and Nuclear Medical Systems gave similar satisfactory results. That from Pharmacia was somewhat more difficult to use and gave greater coefficients of variation. Diagnostic Products' kit appeared to perform satisfactorily, but the analytical values obtained were significantly low, which may suggest erroneous calibrator values within the kit.
Reactivation of serum creatine kinase isoenzyme BB in patients with malignancies.
Authors: Abbott L B , Lott J A 
Published: January 2020

Abstract
Reactivation of serum creatine kinase isoenzyme BB (CK-BB) with 2-mercaptoethanol and EDTA increased the electrophoretic detection rate of CK-BB from 34% to 78% in 58 hospitalized patients with various malignancies. Patients with solid tumors showed the largest and patients with hematologic malignancies the smallest percentage increase in CK-BB after reactivation. For serum from 50 hospitalized patients without cancer, reactivation resulted in detectable CK-BB in two patients; the CK-BB band was never seen in 15 healthy adults. For reasons unknown, five of eight patients with senile dementia of the Alzheimer's type showed CK-BB in serum after reactivation, as did two of five patients suspected of having this disorder. Serum CK-BB may be a useful tumor marker if reactivation with a thiol and EDTA is used immediately after collection.
Particle-enhanced turbidimetric inhibition immunoassay for theophylline evaluated with the Du Pont aca.
Authors: Opheim K E , Glick M R , Ou C N , Ryder K W , Hood L C , Ainardi V , Collymore L A , DeArmas W , Frawley V L , Hutchinson J 
Published: January 2020

Abstract
We evaluated the Du Pont Particle-Enhanced Turbidimetric Inhibition Immunoassay (PETINIA) for theophylline. The imprecision (CV) of the assay was less than 4.7% between-run and less than 3.6% within-run for theophylline concentrations between 5 and 30 mg/L. Standard curves for the assay were linear for theophylline concentrations from 0 to 46 mg/L and were stable throughout the study (i.e., for at least three months). The monoclonal antibody against theophylline used in this assay increases specificity; of the possibly interfering drugs, metabolites, and anticoagulants tested, only 1,3-dimethyluric acid and EDTA showed measurable effects. Bilirubin (less than 300 mg/L), hemoglobin (less than 6 g/L), or lipemia (triglycerides less than 6 g/L) does affect the quality of the assay. Analytical recovery of theophylline added to serum (5 to 40 mg/L) averaged 98% (range 93% to 112%). Comparison of results for patients' sera by the PETINIA method with those by enzyme immunoassay (EMIT) and by "high-performance" liquid chromatography yielded slopes and intercepts not significantly different from 1.0 and 0.0, respectively, and correlation coefficients ranging from 0.986 to 0.995.
Two-dimensional electrophoretic analysis of cytosols from human breast tumors: optimal migration conditions.
Authors: Motté P , Bidart J M , Delarue J C , Comoy E , Moingeon P , Bohuon C 
Published: January 2020

Abstract
In an examination of cytosols from human breast tumors, we performed two-dimensional electrophoretic analysis. Several migration conditions were tried in a search for a homogeneous repartition of cytosolic proteins. The most workable gels were obtained with a 4.40 to 8.05 pH gradient in the first dimension and a homogeneous 125 g/L acrylamide/sodium dodecyl sulfate gel, 1 mm in thickness, in the second dimension. The practicability of this method is discussed.
Protein-pattern changes and morphological effects due to methionine starvation or treatment with 5-azacytidine of the phorbol-ester-sensitive cell lines HL-60, CCL-119, and U-937.
Authors: Anderson N L , Gemmell M A 
Published: January 2020

Abstract
Methionine starvation causes changes in the protein pattern of HL-60 promyelocytic leukemia cells as observed by two-dimensional electrophoresis. One group of proteins is apparently modified, appearing in new positions. A further series of proteins, including several principal nuclear polypeptides, is substantially diminished. The morphology of a fraction of the cells in the culture changes concomitantly, with condensation and fragmentation of the nucleus and eventual remolding of the cell to a "grape-cluster" appearance. Similar effects are produced by a DNA methylation inhibitor, 5-azacytidine, but not by various other toxic agents tested. A defect in DNA methylation, either by depletion of S-adenosyl-L-methionine (the methyl donor) or by inactivation of the relevant enzyme, may be responsible. The T-lymphoblastoid line CCL-119 and the histiocytic lymphoma line U-937 also show these effects, but most fibroblast, epithelial, and lymphoblastoid lines do not. These changes can be largely prevented in each of the three susceptible lines by prior treatment with the tumor promoter, phorbol myristate acetate (PMA), an agent known to cause differentiation in at least two of the lines. The results thus suggest interesting relationships between methionine metabolism, protein and structural changes in the cell nucleus, and PMA-induced cell differentiation.
Spot identification in two-dimensional patterns by a least-squares template matching.
Authors: Pardowitz I , Zimmer H G , Neuhoff V 
Published: January 2020

Abstract
The coordinates of the center of measured spots are nonlinearly transformed to get an optimal match between the transformed coordinates and the given coordinates of a reference pattern. The parameters of the transformation are determined by the minimum of a function of squared distances between all spots of the sample and of the reference pattern. The algorithm requires a priori defined correspondences between some pivot points in the sample and the reference and treats their distances differently from the others. The parameters of the transformation are the solutions of a system of nonlinear equations; their numerical values are obtained by iteration.
Computerized comparison of two autoradiographs.
Authors: Hruschka W R 
Published: January 2020

Abstract
Our laboratory previously reported (Anal Chem 55: 2345-2348, 1983) the development of a digitizer and FORTRAN program for display and quantification of digitized autoradiographic images. We have since added several capabilities to the program. Coarse "rubber sheeting" (i.e., transforming coordinates to superimpose images) of the image by a quadratic transformation of pixel coordinates is developed from interactive identification of a few matching spots. The program determines thresholds to display a given proportion of the total protein in the image, or a given number of proteins, and it creates a protein list containing the spatial coordinates of each protein with a peak value above this threshold, together with the amount of the protein as measured by the ratio of its integrated intensity above its half-maximum to the total integrated intensity of the image. The lists can be stored on a disk and are used as the primary data for fine adjustments to superimpose images, quantitative comparison of images, and abstract display of proteins. Methods are discussed for presenting comparisons between gels in cases where spots for many proteins change in intensity.
Two-dimensional electrophoresis used to differentiate the causal agents of American tegumentary leishmaniasis.
Authors: Saravia N G , Gemmell M A , Nance S L , Anderson N L 
Published: January 2020

Abstract
American tegumentary leishmaniasis is caused by a diverse group of Leishmania classified within two species complexes: L. mexicana and L. braziliensis. Because distinct disease forms are associated with certain species or subspecies, prognosis requires taxonomic identification of the pathogen. Biological criteria allow identification only to the species level; thus, biochemical and immunological markers are eagerly sought. We have used two-dimensional electrophoresis to examine the relationships among reference strains of New World Leishmania and stocks isolated from Colombian patients. The L. mexicana and L. braziliensis species complexes are shown to be extremely disparate, and the relative affinities of the subspecies reference strains and Colombian Leishmania stocks are documented. The latter displayed a variety of patterns--some clearly identifiable with a particular L. braziliensis subspecies reference strain, others intermediate between those of L.b. panamensis and L.b. guyanensis. Such comparisons are useful both in establishing relatedness and identifying subspecies and variant marker proteins, which may have biological significance.
A "high-performance" 2D gel scanner.
Authors: Kronberg H , Zimmer H G , Neuhoff V 
Published: January 2020

Abstract
We describe the design principles of a photometric flatbed scanner with a scan area of 250 X 250 mm2, a dynamic range of 4000 gray levels, a signal/noise ratio of 2000/1, a step size of 0.1 mm, and a step frequency of 2000 steps per second. It is controlled by a microcomputer and used to acquire data for quantitative evaluation of gels or chromatograms. The performance of the instrument is demonstrated by the data obtained by scanning gratings, gray step filters, and high-resolution electropherograms.
Myosin light chain phosphorylation and tension development in stretch-activated arterial smooth muscle.
Authors: Ledvora R F , Bárány M , Bárány K 
Published: January 2020

Abstract
Phosphorylation of the 20 000-Da light chain of myosin in functionally different porcine carotid arteries was determined, with use of two-dimensional gel electrophoresis. Stretching arteries to 1.7 times their resting length resulted in maximal phosphorylation. Intracellular Ca2+ was mobilized for stretch-induced light chain phosphorylation. Releasing the stretch from the arteries produced active tension spontaneously, without the participation of any exogenous stimulating agent. Prolonged treatment of arteries with a chelating agent (EGTA) not only abolished stretch-induced phosphorylation, it also prevented the development of active tension when the stretch was released. However, when the EGTA was washed out and the strips were restretched and again released, the stretch-induced phosphorylation and the stretch-release-induced active tension were restored. Evidently, arteries must contain phosphorylated light chain if they are to produce active tension. The myosin light chain became partly dephosphorylated in arteries that developed active tension when the stretch was released, but more than half of the light chains remained phosphorylated. This result suggests that phosphorylation of light chain is involved, not in the generation of active tension, but rather in activation of smooth muscle.
Molecular characterization of an abnormal fibrinogen by two-dimensional electrophoresis.
Authors: Polack B , Valiron O , Concord E , Freyssinet J M , Hudry-Clergeon G 
Published: January 2020

Abstract
We examined normal and abnormal fibrinogen (fibrinogen "Grenoble") by two-dimensional gel electrophoresis to obtain data on possible defects at the molecular level. Fibrinogen Grenoble is characterized by an abnormal rate of fibrin monomer aggregation. The electrophoretic analysis revealed the presence of abnormal gamma chains. Two kinds of gamma chains can be detected in fibrinogen Grenoble: (a) normal gamma chains and (b) gamma chains Grenoble (gamma G) with a greater molecular mass but no modification in isoelectric point. The latter chain can be detected in whole plasma by two-dimensional gel electrophoresis. Metrological analysis was performed in an attempt to quantify observed differences between normal fibrinogen and fibrinogen Grenoble. On use of gels stained either with Coomassie Brilliant Blue or with silver, the partly qualified evaluation gives about 60% normal gamma chain and 40% gamma chain Grenoble.
Roche RIA and Abbott EIA carcinoembryonic antigen assays compared.
Authors: Fleisher M , Nisselbaum J S , Loftin L , Smith C , Schwartz M K 
Published: January 2020

Abstract
We have evaluated Roche Diagnostics' RIA-CEA and Abbott Diagnostics' EIA-CEA methods for precision, normal reference interval, concordance, and correlation of malignant disease with increase in carcinoembryonic antigen (CEA) in plasma. In examining concordance, we used data on 138 patients with primary carcinomas of the breast, colon, lung, or pancreas, each further classified by extent of dissemination. We find the two methods to be comparably precise. The respective upper reference limits of normal for the Roche and Abbott methods were determined to be 5.0 micrograms/L and 4.6 micrograms/L. The regression equation for a log transformation of the 177 data points is y = 0.966x + 0.03, where x = Roche and y = Abbott, with a correlation coefficient of 0.948. According to the criteria we used, the concordance was 78.7%. The largest discordance was observed in widely disseminated disease states and in cancers of the colon and pancreas. Paired data analysis of discordance indicated greater increases in apparent CEA by the Abbott method in most colon cancers with liver involvement; six of the eight discordant pancreatic cancers had higher Roche-CEA values. CEA heterogeneity and the role of the liver in CEA metabolism appear to contribute to the observed differences. We show why the two methods should not be used interchangeably, and that baseline values for CEA must be established for each method.
A family with a high serum aminopeptidase (microsomal) activity: properties of the enzyme from serum of the propositus.
Authors: Hiwada K , Tokioka-Terao M , Nishimura K , Kokubu T 
Published: January 2020

Abstract
We found a family with a high activity for hydrolyzing L-alanyl-beta-naphthylamide in their serum. This enzyme was confirmed to be aminopeptidase (microsomal) (EC 3.4.11.2) by means of immunological experiments involving anti-human kidney aminopeptidase (microsomal) antibody. We could not find the cause of the increased activity from the results of clinical and laboratory examinations. The enzyme from the propositus resembled that from the serum of normal subjects in molecular mass (240 000 Da), Km value (87 mumol/L), and degree of inhibition by antiserum to human kidney aminopeptidase (microsomal). It differed from the normal enzyme with respect to electrophoretic mobility (R1 value, 0.58; normal, 0.51), isoelectric point (pI, pH 3.4; normal, pH 3.8), and heat stability (more labile than normal). From information on this family and another one reported in the Japanese literature, we suggest that the mode of inheritance of a high activity of serum aminopeptidase (microsomal) may be autosomal dominant.
Reduction of organic mercury in water, urine, and blood by sodium borohydride for direct determination of total mercury content.
Authors: Margel S , Hirsh J 
Published: January 2020

Abstract
We have established the optimal conditions for use of sodium borohydride as the reducing agent before the direct determination of mercury in water, urine, and blood by atomic absorption spectroscopy. We evaluated the effects of pH, temperature, and cupric sulfate concentration on the direct determination of both organic and inorganic compounds of mercury. Accurate and precise quantification of mercury requires that the pH be between 9.3 and 9.5, the reaction temperature above 25 degrees C, the reaction time longer than 1 min, and, for urine samples only, the cupric sulfate concentration 10 mumol/L. The detection limit of the method is 1 to 2 ng and the precision (CV) is 3.8% for blood and 4.0% for urine.
An evaluation of the Technicon RA-1000 random-access analyzer.
Authors: Bromberg I L , Pollard A , Cheng J , Romaschin A 
Published: January 2020

Abstract
We evaluated the Technicon RA-1000 analyzer, with emphasis on its potential for user-defined method development. Optical linearity and sample pipetting linearity were good. The reagent pipetting system delivered slightly less than the nominal amount, owing to the volumetric effect of added mixing bubbles. Carryover of aqueous solutions was negligible. The instrument had good adaptability for user-defined methods and performed well in method comparisons. The observed dynamic range for enzymes (0-3000 U/L) was excellent. The worklisting software performed its intended functions well, but has limitations. We believe that the RA-1000 represents a significant contribution to the practice of clinical chemistry. A sophisticated benchtop machine, it includes several innovations, along with a few problems that are peculiar to its technology.
How to improve estimates of imprecision.
Authors: Krouwer J S , Rabinowitz R 
Published: January 2020

Abstract
Authors sometimes report total imprecision as being less than within-run imprecision. This leads one to question how well the underlying statistical concepts are understood. This article explains statistical concepts relevant to imprecision studies and reviews proper use of the relevant statistical terms. Calculation of total imprecision and its components is illustrated by a numerical example. Two of the most common calculation mistakes are pointed out. Finally, we recommend improvements in experimental design that will result in more precise estimates.
Use of a reference standard to improve the accuracy and precision of seven kits for determination of ferritin in serum.
Authors: Iacobello C , Ghielmi S , Belloli S , Arosio P , Albertini A 
Published: January 2020

Abstract
We assessed the accuracy and precision of seven commercial kits for serum ferritin. The concentration of ferritin as determined by these assays for a liver ferritin reference standard, a human heart ferritin standard, and normal sera correlated highly, but the absolute values varied widely. Use of an international reference standard for ferritin to prepare the standard curve greatly diminished the variability, but did not eliminate it. Although the seven kits differed in specificity for various human isoferritins, this did not appear substantially to affect accuracy. Six of the seven kits appeared sufficiently precise for clinical use over a wide range of ferritin concentrations.
Liquid-chromatographic evaluation of age-related changes in the urinary excretion of free catecholamines in pediatric patients.
Authors: Rosano T G 
Published: January 2020

Abstract
Pediatric patients (to age 18) without neuroblastoma show an age-related decrease in urinary excretion of each of the catecholamines--epinephrine, norepinephrine, and dopamine--in relation to creatinine excretion. From these data, I have developed reference intervals for pediatric age groups. Application of these ranges to seven patients with neuroblastoma and ganglioneuroblastoma indicated a high clinical sensitivity for the urinary dopamine determination but significant false-negative results for epinephrine and norepinephrine.
Plasma enzyme activities in primary hypothyroidism.
Authors: White G H , Walmsley R N 
Published: January 2020

Abstract
Results of clinical chemistry tests are often initially interpreted by relatively inexperienced junior medical staff, and therefore a major role of clinical chemists is to ensure that their laboratory tests are utilized and interpreted appropriately. The cases described below demonstrate the interaction of a diagnostic problem and clinical inexperience in an area where clinical chemists can, and should be, of professional assistance.
Influence of incomplete cholesteryl ester hydrolysis on enzymic measurements of cholesterol.
Authors: Wiebe D A , Bernert J T 
Published: January 2020

Abstract
Esterolytic activity of three enzymic cholesterol reagents was evaluated with use of human serum-based reference materials. Primary cholesterol standards were used to calibrate the enzymic methods, and incomplete cholesteryl ester hydrolysis was measured as the bias between the enzymic cholesterol values and corresponding reference values. The average biases observed with eight reference specimens were 0.15, -1.16, and -7.24%, respectively, for a commercial enzymic reagent with microbial cholesterol esterase, a commercial reagent with an animal source of esterase, and a Centers for Disease Control (CDC) reagent preparation with a microbial cholesterol esterase. By liquid chromatography, we examined the respective specificities of the three esterase reagent preparations and found that the preparations differ in the rate and specificity of catalysis of cholesteryl ester hydrolysis. The CDC reagent was only partly active towards cholesteryl arachidonate, which probably accounts for most of the negative bias of this reagent. Esterolytic activity of the various enzymic reagents is related to the source and matrix of the cholesterol esterase and must be considered with respect to proper selection of calibration materials for serum cholesterol measurement.