bluuebunny/crossref_metadata_2025_split huggingface dataset:
beta-Glucosidase assays in the diagnosis of Gaucher's disease.
Authors: Daniels L B , Glew R H 
Published: January 2020

Abstract
The description in 1965 of glucocerebroside: beta-glucosidase as the enzymic defect in Gaucher's disease stimulated considerable research interest and effort toward establishing rapid, reliable, and inexpensive enzymic assays for diagnostic purposes and carrier detection. Here, we consider some of the methods currently in use in which the substrate is the synthetic glucoside, 4-methylumbelliferyl-beta-D-glucopyranoside, and leukocytes and fibroblasts are the sources of enzyme. We also consider the concepts of the "acid beta-glucosidase" and multiple forms of beta-glucosidase that have been proposed to explain the effectiveness of the fluorometric assays. Finally, we analyze the limitations of each method and discuss the difficulties involved in instituting heterozygote screening programs in the general population.
Optimized bioluminescence assay of creatine kinase and creatine kinase B-subunit activity.
Authors: Lundin A , Jäderlund B , Lövgren T 
Published: January 2020

Abstract
Spectrophotometry of CK-B subunit activity based on immunoinhibition is rapid and convenient. However, the low sensitivity limits clinical applications to serum samples with CK-B activities considerably above normal. A sensitive, but not optimized, bioluminescent assay of CK-B, also based on immunoinhibition, has been described. We improved this method by the use of an ADP concentration saturating the CK reaction and by the combined use of AMP and diadenosine pentaphosphate for inhibition of adenylate kinase. The optimized bioluminescent method is similar to the corresponding spectrophotometric method (reaction conditions, analytical procedure, numerical results, etc.) and results by the two methods correlate well. However, the measuring time is shorter and, more important, the sensitivity of the bioluminescent method allows accurate determinations of CK-B, even in serum from healthy individuals (CV approximately 3%). Kits and instrumentation (manual and automatic) for determination of CK and CK-B are now commercially available.
Screening test for alpha 1-antitrypsin in dried-blood specimens.
Authors: Orfanos A P , Naylor E W , Guthrie R 
Published: January 2020

Abstract
We describe a fluorescent spot test for detecting alpha 1-antitrypsin activity in dried-blood specimens. The eluate of a blood disc is mixed with carbobenzoxy-L-arginine-7-amino-4-methylcoumarin amide and trypsin at the appropriate pH. In the absence of alpha 1-antitrypsin, aminomethylcoumarin, a strongly fluorescent compound, is released. The reaction mixture, when spotted on chromatography paper and viewed under ultraviolet light, exhibits a bright fluorescence only in the case of specimens with alpha 1-antitrypsin deficiency. alpha 1-Antitrypsin activity so estimated correlated well with quantitative assays of dried-blood spots and serum. The procedure is simple and inexpensive, and has the potential for use as a screening test.
Radioimmunoassay of serotonin (5-hydroxytryptamine) in cerebrospinal fluid, plasma, and serum.
Authors: Engbaek F , Voldby B 
Published: January 2020

Abstract
We describe a direct radioimmunoassay for serotonin (5-hydroxytryptamine) in cerebrospinal fluid, platelet-poor plasma, and serum. We raised antisera in rabbits against serotonin diazotized to a conjugate of bovine albumin and D,L-p-aminophenylalanine. Polyethylene glycol, alone or in combination with anti-rabbit immunoglobulins, is used to separate bound and unbound tritiated serotonin. The minimum concentration of serotonin detectable is 2 nmol/L in a 200-microL sample. Within-day precision (CV) is 4.3%, between-day precision 7.7%. Analytical recoveries of serotonin are 109% and 101% for cerebrospinal fluid and plasma, respectively. Tryptophan, 5-hydroxytryptophan, 5-hydroxyindoleacetic acid, and 5-hydroxytryptophol do not interfere with the assay. However, 5-methoxytryptamine and tryptamine cross react. Of samples of cerebrospinal fluid from patients with disc herniations (n = 21) or low-pressure hydrocephalus (n = 10), one-third had concentrations of 2-4 nmol/L and two-thirds were below the minimum detectable concentration. The observed range for the concentration of serotonin in plasma of 14 normal subjects was 5-14 nmol/L (mean +/- SD, 9 +/- 3 nmol/L). The observed ranges for serotonin in serum were: for 10 women 520-900 (mean +/- SD: 695 +/- 110) nmol/L and for 10 men 380-680 (520 +/- 94) nmol/L.
X-Ray fluorescence measurement of the zinc profile of a single hair.
Authors: Toribara T Y , Jackson D A 
Published: January 2020

Abstract
Many trace elements appear in hair in concentrations related to those in the blood, but the relationship for zinc is complicated by disorders that probably affect its state in the blood. A built-to-order x-ray fluorescence spectrometer was used to measure, nondestructively, the concentrations of 16 elements in a 1-mm interval of a single hair. A scan along a hair strand, together with the known growth rate, enables the zinc concentration in the hair to be correlated with the time the hair was formed. A comparison with the blood concentration at the same time may reveal possible bodily disorders that affect the availability of zinc to incorporation in the hair. The instrument has been carefully calibrated for zinc, and we studied the conditions under which there can be losses or gains in the hair after sampling. The sample chamber will accommodate 16 separate holders, and each sample may be automatically measured according to a program pre-selected for it. The average zinc content of hair samples from foreign countries, some ancient specimens, and an interesting profile of a strand from an Iraqi woman are shown.
Analysis of phosphate in serum with the phosphate redox electrode system.
Authors: Montalvo J G , Truxillo L A , Wawro R A , Watkins T A , Phillips A , Jenevin R M 
Published: January 2020

Abstract
A phosphate redox electrode system (PRES) was designed, constructed, and evaluated for analysis of inorganic phosphate in serum. This system is based on the observed phosphate ion potential of a chemically treated iron wire in a turbulent flow-through cell at constant oxygen tension. We analyzed 110 clinical samples by this technique and with the Technicon SMAC. Of the specimens analyzed, 32% contained abnormal phosphate concentrations. Each was assayed two to four times with the PRES and once with the SMAC. The PRES assay rate was 60 samples/h. Mean phosphorus concentrations (and SEM) were: PRES, range of values for replicate data sets, 30.5-31.0 (0.5-1.1) mg/L; SMAC, 30.8 (1.0) mg/L. Results for the PRES (y) correlated well with those by the SMAC: r = 0.968 to 0.980, estimated slope = 0.99 to 1.03, and estimated intercept = -1.1 to 0.1 mg/L. Differences in results by the two methods were not statistically significant.
Clinical studies of protein-bound calcium in various diseases.
Authors: Duncan P H , Wills M R , Smith B J , Savory J 
Published: January 2020

Abstract
A recently developed gel-filtration technique allows protein-bound calcium fractions to be separated and quantitated; the protein is separated under physiological conditions of pH, temperature, and concentrations of Na, Mg, and Ca to assure that the calcium-proteinate equilibrium is not disturbed. We used this gel-filtration technique to study the protein-bound calcium fractions in 18 patients with hyperparathyroidism, multiple myeloma, diabetes, osteoporosis, or liver cirrhosis. We calculated the amount of calcium bound per gram of protein for each of the three protein peaks and the intrinsic association constant (Ka) for calcium/albumin. Results with the multiple myeloma patients (three IgG, one IgA) indicated that IgG did not bind calcium appreciably, that IgA had about the same affinity as albumin for Ca, and that Ka was slightly low for one patient of the IgG type (79 L/mol) and normal for the other three myeloma patients (106, 90, and 91 L/mol). Results for patients with the other diseases were also essentially normal, except for the osteoporesis patients (two men, one woman), whose Ka values (69, 75, and 73 L/mol) were lower than normal.
Direct determination of the linoleate/oleate ratio in serum cholesterol esters by liquid chromatography.
Authors: Bernert J T , Akins J R , Miller D T 
Published: January 2020

Abstract
We describe a convenient method for the direct determination of the serum cholesterol linoleate/cholesterol oleate (L/O) ratio by reversed-phase "high-performance" liquid chromatography. After removal of phospholipids by silicic acid chromatography, a serum extract is analyzed on a 5-micrometers particle size Ultrasphere-ODS column, eluted isocratically with acetonitrile/isopropanol (30/70, by vol). Detection is at 200 nm. Cholesterol palmitoleate interferes with the measurement when the analysis is based on peak area, but not when peak height is used. The overall precision of L/O measurements by this method was very similar to that observed with a gas-liquid chromatographic procedure, in which the cholesterol esters are first isolated and transesterified to the methyl esters. In both cases, the within-run CV for six replicate analyses was less than 2%. Analysis of 53 human serum samples by both methods yielded very similar L/O ratios. A plot of the data (our method = y) vs the usual gas-liquid chromatographic procedure gave a correlation coefficient of 0.988 and a regression equation of y = 1.03x + 0.013. Furthermore, direct analysis of serum cholesterol ester L/O ratios by our liquid-chromatographic method is simpler, quicker, and more readily adaptable to automation.
Up-dated catalogue of HeLa cell proteins: percentages and characteristics of the major cell polypeptides labeled with a mixture of 16 14C-labeled amino acids.
Authors: Bravo R , Celis J E 
Published: January 2020

Abstract
A total of 1357 polypeptides [946 acidic (isoelectric focusing) and 411 basic (nonequilibrium pH-gradient electrophoresis)] from human HeLa cells have been separated and catalogued with use of high-resolution two-dimensional gel electrophoresis. Of these polypeptides, 1266 were detected by labeling cells with [35S]methionine, while the rest were revealed by silver staining or by labeling with a mixture of 16 14C-labeled amino acids. For convenience, all these polypeptides have been numbered and are indicated in a large fold-out protein map. The percentages of some of the major 14C-labeled proteins have been determined, and for some we list a few characteristics such as: variation during the cell cycle; cellular distribution in cytoplasts and karyoplasts; presence in Triton- and salt-extracted cytoskeletons; and phosphorylation and sensitivity to neoplastic transformation.
Two-dimensional gel electrophoresis of human brain proteins. III. Genetic and non-genetic variations in 145 brains.
Authors: Comings D E 
Published: January 2020

Abstract
To determine the frequency of genetic mutations, polymorphisms, and non-genetic variation in the major human brain proteins, I examined, by equilibrium two-dimensional gel electrophoresis, 145 brains from patients dying of a wide variety of psychiatric, neurological, and non-neurological disorders. Of 176 polypeptides screened, there was one polymorphism of glial fibrillary acidic protein (GFAP-Duarte). Chi square analysis indicated it was non-randomly distributed among different diseases. A possible mutation associated with Joseph's disease is being further investigated. Three examples of a possible mutation of protein 8c:1 were noted. No other genetic mutations were observed. This low frequency of polymorphisms is consistent with results for two-dimensional gel analysis of other tissue and species. The numerous non-genetic variations are described.
Two-dimensional gel electrophoresis of human brain proteins. IV. Disorders of glial proliferation and a polymorphism of glial fibrillary acidic protein--GFAP Duarte.
Authors: Comings D E 
Published: January 2020

Abstract
Several genetic and non-genetic neurological disorders are characterized by neuronal cell death, followed by astrocytic glial cell proliferation. Because the major intermediate filament in astrocytes is glial fibrillary acidic protein (GFAP), large amounts of this protein accumulate. The two-dimensional gel-electrophoretic pattern of gliosed tissue is described. It shows a massive accumulation of the 50 000-dalton GFAP charge isomers (8e:1--8) plus a series of breakdown products of lower molecular mass and more-acid charge. In addition, I describe a genetic polymorphism, GFAP-Duarte, presenting as an additional, basic charge isomer of GFAP. The possibility that this or other mutations of GFAP may predispose certain neurons to premature cell death is discussed.
Actin mutations in a human fibroblast model for carcinogenesis.
Authors: Leavitt J , Goldman D , Merril C , Kakunaga T 
Published: January 2020

Abstract
We assessed the modulation of gene expression accompanying neoplastic transformation by computerized microdensitometry of autoradiographic patterns of [35S]-methionine-labeled polypeptides separated by two-dimensional polyacrylamide gel electrophoresis. Nearly 1000 polypeptide species of parent diploid human fibroblasts (KD strain) and clonally-derived malignant fibroblasts (HUT-14 strain) were compared. We found that the neoplastic HUT-14 fibroblasts express a mutation in one of the two functional beta-actin genes. In addition, of the 700 more-abundant polypeptides measured, 13 were lost and 14 new ones gained after this neoplastic transformation. We estimate that although 2% of fewer of the genes expressing abundant polypeptides were either activated or shut off, at least 32% were modulated quantitatively. A substrain of HUT-14--HUT-14T--shows increased tumorigenicity, producing larger, faster-growing fibrosarcomas in the nude mouse than does the present parent HUT-14 strain, and with fewer inoculated cells. This increase in tumorigenicity is accompanied by three subsequent changes in the mutant beta-actin polypeptide expression. A more variant mutant actin species is synthesized in HUT-14T, which differs from the original mutant polypeptide by (i) one additional negative net charge, (ii) a short half-life in the cell, (iii) a greatly diminished ability to incorporate into the detergent-resistant cytoskeleton, (iv) a decrease in affinity for deoxyribonuclease I (EC 3.1.21.1), and (v) a faster rate of synthesis. Our results suggest that a second-site mutation in the mutant beta-actin of HUT-14 was selected for during a subcloning step in the presence of 6-thioguanine before derivation of the HUT-14T substrain. This apparent mutation and two subsequent defective beta-actin expressions are accompanied by incremental increases of malignant potential.
Two-dimensional gel electrophoresis of serum specimens from patients with monoclonal gammopathies.
Authors: Tracy R P , Currie R M , Kyle R A , Young D S 
Published: January 2020

Abstract
We modified the ISO-DALT two-dimensional gel electrophoresis system to allow the routine examination of serum specimens from patients with monoclonal gammopathies. This system, MC-Iso 1, is characterized by a broad pH gradient for resolving the basic immunoglobulin heavy and light chains. The increased resolution of basic proteins may be explained on theoretical grounds by an increase in voltage in this region of the cell. Ancillary techniques, such as those for albumin removal and pI assignment through use of charge standards, have also been implemented. The locations of immunoglobulin heavy chains have been confirmed by examination of over 250 serum samples as well as by "electro-blotting," with use of specific antisera. IgG subclass may also be predicted by location, but not with perfect accuracy. Differentiation of kappa and lambda light chains by relative mobility has been examined; the predictive value for correct identification of kappa chains is 83%, that for lambda chains 69%. Several unknown proteins have been observed in macroglobulinemia, related to mu heavy chain. Finally, we have determined that there is excellent correlation between non-denaturing isoelectric focusing and our system for pI assignment of light chains. This has importance due to reports of the potential importance of light-chain pI in the development of renal disease in patients with monoclonal gammopathies.
Two-dimensional electrophoretic analysis of erythrocyte membranes.
Authors: Rosenblum B B , Hanash S M , Yew N , Neel J V 
Published: January 2020

Abstract
In an effort to maximize the amount of genetic information that can be extracted from a blood sample, we investigated the use of two-dimensional polyacrylamide-gel electrophoresis (PAGE) to resolve the protein constituents of the erythrocyte membrane. Lyophilized membranes were dissolved in various concentrations of urea, NP-40 detergent, and mercaptoethanol and subjected to two-dimensional PAGE by a modification of the O'Farrell procedure, with use of the ISO-DALT apparatus. More than 600 spots were visible in silver-stained gels under conditions that excluded specific cytoskeleton protein components, including spectrin and actin. The reproducibility of the pattern depended highly on the precise composition of the solubilization mixture. Poor resolution was observed in the presence of actin and other proteins of high molecular mass (spectrin bands 1 and 2) when we used high urea concentrations that solubilized the entire erythrocyte membrane. The large number of polypeptides observed could not be attributed to proteolysis, because addition of proteolytic inhibitors to the membrane wash solutions did not alter the pattern on the gel. The pattern also did not appear to include erythrocyte cytosol proteins because, except for globin, none of five purified erythrocyte lysate proteins was visible in the erythrocyte membrane gels. We conclude that two-dimensional electrophoresis provides a powerful tool for the study of non-cytoskeletal erythrocyte membrane proteins.
Analysis of protein patterns in two-dimensional gels of cultured human cells with trisomy 21.
Authors: Klose J , Zeindl E , Sperling K 
Published: January 2020

Abstract
The occurrence of one chromosome of the cell in triplicate (trisomy, Ts) should increase the amount of all cell proteins coded by genes located on this chromosome. Many other proteins should be altered in their quantity by regulator genes, present in a threefold dosage, and by several indirect effects of the trisomy. We used two-dimensional electrophoresis to investigate the effect of the human Ts 21 on the proteins. Cells from different individuals with Ts 21 were cultured. Seven cell lines were derived from skin tissue and four from cells in amniotic fluid, and two cell clones were raised from fetal lung with Ts 21 mosaic. Stained two-dimensional protein patterns from these cell lines were compared with control patterns, and clearly visible differences in the staining intensity of corresponding polypeptide spots were evaluated. A few quantitatively variant polypeptides occurred in all trisomic cell lines investigated that were of a particular cell type, but no variants were consistently present in all of the 13 cell lines investigated. However the total number of variants (including variants not found in all individual cell lines) was considerably higher in trisomic cells than in normal cells.
Two-dimensional gel electrophoresis can be used to examine chromatographic effluent fractions from displacement column chromatography.
Authors: Torres A R , Krueger G G , Peterson E A 
Published: January 2020

Abstract
We show how two-dimensional gel electrophoresis can be used to monitor protein components in effluent fractions from a displacement column. A minor protein in human serum, of interest in studies on psoriasis and highly enriched by using carboxymethyldextrans as displacers on DEAE-Sephacel, was easily detected in the effluent fractions with the two-dimensional gel method because its concentration was sufficiently high and there was no interference by the carboxymethyldextrans or salt.
Clinical applications of protein determinations in biological fluids other than blood.
Authors: Killingsworth L M 
Published: January 2020

Abstract
Over the past decade, significant improvements in immunochemical and electrophoretic techniques have enabled collection of heretofore unavailable data on proteins in biological fluids, greatly increasing our understanding of protein physiology in the various body compartments and providing the foundation for clinical use of protein analysis in body fluids. The most striking advance has been in the diagnosis of demyelinating disease through the use of serum/cerebrospinal fluid protein ratios and the morphological evaluation of immunoglobulin banding patterns. These laboratory tests are now considered obligatory for any patient in whom demyelinating disease is suspected as the cause of neurological dysfunction. Cerebrospinal fluid protein data can also be helpful in quantitating the permeability of the blood/cerebrospinal fluid barrier in many inflammatory or infectious central nervous system disorders. Assays of individual proteins in urine can help distinguish between different types of proteinuria, and can give quantitative data on the selectivity of the glomerulus and the reabsorbing capacity of the tubules. The protein content of saliva, synovial fluid, and milk has also been well characterized, and is clinically applicable to a wide range of disorders.
Interference of immunoglobulins in two glucagon radioimmunoassays.
Authors: von Schenck H , Grubb A O 
Published: January 2020

Abstract
Radioimmunoassays of glucagon in plasma may be complicated by interaction with other substances of high molecular mass. Precipitates of such substances with ammonium sulfate showed, after isoelectric focusing, two fractions having glucagon immunoreactivity. One fraction (pl approximately 10) evidently is associated with the Fc portion (but not the Fab portion) of purified polyclonal immunoglobulin G (IgG). Equal amounts of purified monoclonal IgG of various subclasses, especially IgG 1, gave different "glucagon" readings, suggesting that some IgG may interfere more strongly than others. The other fraction (pI 5-6) appeared less consistently, and on gel chromatography appeared to be slightly larger than IgG. Together these fractions add about 50-100 ng/L to the immunoreactive glucagon values in plasma. Therefore methods in which glucagon is extracted before assay should be used for determining the concentration of glucagon present physiologically.
Radioimmunoassay and lipid-chromatographic analysis for free cortisol in urine compared with isotope dilution--mass spectrometry.
Authors: Lantto O 
Published: January 2020

Abstract
I compared results by three different routine methods for analysis for urinary cortisol with those by a highly specific reference method based on isotope dilution--mass spectrometry (i). A "high-performance" liquid-chromatographic method (II) gave the most comparable results (regression coefficient 0.86, intercept 9 nmol/L). For some urines much lower values were obtained by I than by II. Two radioimmunoassay (III) methods, one involving direct assay and one involving extraction, gave less-accurate results (regression coefficients of 1.87 and 1.52 and intercepts of 86 and 12 nmol/L, respectively, although values obtained by III and by I correlated well (r = 0.95-0.99), indicating a relation between the free cortisol and the compounds interfering in III. The apparent accuracy for the extraction method was previously assayed by I (regression coefficient 0.90, intercept 6 nmol/L). All four methods investigated showed a statistically significant sex-related difference in 24-h urinary cortisol excretion; evidently such a finding should be a prerequisite in any such method proposed for routine use.