bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative two-dimensional protein electrophoresis for studies of inborn errors of metabolism.
Authors: Merril C R , Goldman D 
Published: January 2020

Abstract
High-resolution electrophoretic methods and sensitive protein-detection techniques permit new approaches to understanding and diagnosis of the inborn errors of metabolism. These approaches encompass: the search for protein alterations that represent primary mutations effects; observation of alterations in protein patterns due to secondary effects, as might occur in major metabolic pathway abnormalities; and identification of protein polymorphisms that are genetically linked to an inborn metabolic disease. With the aid of computer analysis of the electrophoretograms, all three approaches are being developed. Protein density and position are evaluated with an interactive computer program that requires that gel polypeptides be indexed by the investigator. Proteins on the gels are made visible with an inexpensive, rapid silver stain, which can be used quantitatively. The Lesch-Nyhan syndrome, one of a few neuropsychiatric diseases for which the molecular defect is known, was chosen for study with these techniques. Four hundred proteins were analyzed for positional or quantitative variation. Eleven significant (2p less than 0.01) quantitative differences were found in autoradiograms from gels of phytohemagglutinin-stimulated lymphocytes. Specific patterns of polypeptide variation are now being sought in an expanded clinical study primarily focusing on Huntington's disease. Large studies are required to establish the specificity of observed alterations. As the number and variety of analyses increase, a correlative catalog of molecular variation and polymorphism will be generated.
Lymphocyte proteins in Huntington's disease: quantitative analysis by use of two-dimensional electrophoresis and computerized densitometry.
Authors: Goldman D , Merril C R , Polinsky R J , Ebert M H 
Published: January 2020

Abstract
We used quantitative two-dimensional electrophoresis to study lymphocyte proteins in Hungtington's disease. Three hundred and six polypeptides from 14C-labeled, phytohemagglutinin-stimulated lymphocytes were measured for variation in relative spot density and 186 for variation in spot position by use of a computer program requiring operator interaction. Each polypeptide was measured in a total of 30 electrophoretograms from 28 individuals, including 13 with Huntington's disease, 2 at risk for it, and 13 controls. The study included two sets of identical twins and, as neurological controls, individuals with neurofibromatosis, Alzheimer's disease, or Shy-Drager syndrome. Seven protein polymorphisms were identified among the 186 most dense polypeptides of each gel, corresponding to a minimum average heterozygosity of 1.4%. Stringent criteria were used to define polymorphic proteins, including observation of at least one individual with each of two homozygous phenotypes and one with the heterozygous phenotype, demonstration of the expected gene dosage relationship by quantitative densitometry, consistency with genetic relationships, and reproducibility. One polymorphic protein showed three electrophoretically variant alleles. Our identification of seven polymorphisms among the 186 proteins measured on a single electrophoretogram illustrates the potential of this technique for performing linkage analysis in diseases of genetic origin. However, we observed no quantitative or positional protein variations that were characteristic of (i.e. specific for) Huntington's disease.
Two-dimensional electrophoresis in basic and clinical research, as exemplified by studies on the exocrine pancreas.
Authors: Scheele G A 
Published: January 2020

Abstract
I summarize our experience in the development and use of two-dimensional isoelectric focusing/SDS gel electrophoresis for the study of soluble proteins, in particular those of the exocrine pancreas. The importance of adding protease inhibitors to the first-dimension isoelectric focusing gel to prevent the autoactivation of potential pancreatic proteases and subsequent proteolysis is discussed. Recently developed methods for both the indirect and direct identification of protein spots by biological activity are summarized. I give examples of the importance of this technique in the study of basic mechanisms involved in the synthesis, segregation, and secretion of exportable proteins in the exocrine pancreas, as well as in the search for biochemical markers of pancreatic disease.
Two-dimensional analysis of human lymphocyte proteins II. Regulation of lymphocyte proteins by a molecule present in normal human urine.
Authors: Willard K E 
Published: January 2020

Abstract
Lymphocytes cultured with concentrated human urine develop many alterations (Clin. Chem. 27:1327, 1981). New proteins appear ("Urocon" proteins), while others disappear ("Urocof" proteins) from the two-dimensional gel pattern. This paper characterizes a human urinary leukocyte effector protein ("HULEP") that is responsible for the appearance of the Urocon:11-15 proteins in human lymphocytes. The effector molecule, HULEP-1, is a protein with a relative molecular mass in the range of 29000 to 43000. Urocon:11-15 production, cytoskeletal changes in the lymphocyte, and the presence of added HULEP-1 in the cultures are all directly related. This molecule appears to alter the structure of the lymphocyte by degrading actin and possible other lymphocyte cytoskeletal proteins. Peptide maps of Urocon:11-15 and beta and gamma actin provide evidence that Urocon:11-15 proteins are closely related to nonmuscle actin, and may be degradation products of this major cytoskeletal protein.
Determination of lipids, including medium-chain fatty acids, in human feces.
Authors: Esteves W , Soares L A , Hartman L , Pereira A S 
Published: January 2020

Abstract
In this method for determining fecal lipids, feces are saponified with ethanolic potassium hydroxide, the ethanol is evaporated, and the acidified residue extracted with hexane. An aliquot of the hexane solution is then titrated with ethanolic sodium hydroxide, the solvents are evaporated, and the residue (soaps and unsaponifiable matter) is weighed. The unsaponifiable matter is extracted with acetone and determined gravimetrically. The method thus permits the determination of milli-equivalents of fatty acids, total lipids, and fatty acids in one sample and is applicable to feces containing medium-chain fatty acids and their triglycerides.
Simple, direct measurement of lipoprotein X in serum.
Authors: Hashiguchi Y , Kawaguchi M , Nakanishi M , Matsumori Y , Kaneda Y , Nakai C , Mimura K , Matsuoka A 
Published: January 2020

Abstract
This relatively simple method for quantitative estimation of lipoprotein X is based on assay of phospholipids in precipitates of lipoprotein X. We first remove other lipoproteins by precipitation with phosphotungstic acid solution. Lipoprotein X is then precipitated from the supernatant fluid with an alkaline solution of magnesium ion, and phospholipid is determined in this precipitate. Results are linearly related to concentration of lipoprotein X. The CV is less than 3%. Results correlated well with those for agar gel electrophoresis.
Macro creatine kinases: results of isoenzyme electrophoresis and differentiation of the immunoglobulin-bound type by radioassay.
Authors: Bohner J , Stein W , Steinhart R , Würzburg U , Eggstein M 
Published: January 2020

Abstract
In 2.9% of sera from 1253 unselected patients we detected two different types of macromolecular creatine kinases (CK; EC 2.7.3.2). One macro type was represented by immunoglobulin-linked CK: in sera containing macro CK-BB isoenzyme, 125I-labeled CK-BB was bound with high affinity to the immunoglobulin fraction. Furthermore, during electrophoresis, macro CK-BB mostly migrated between CK-MB and CK-MM, and was fixed to Protein A from Staphylococcus aureus. We therefore propose radioelectrophoresis as a specific, highly sensitive, and simple method for detecting this type of macro CK. This form occurs predominantly in elderly women, is not correlated to any specific disease, and persists in blood over a long period of time. In contrast, a second type (macro-CK type 2) never bound radiolabeled CK isoenzymes, and was not adsorbed to Protein A. Electrophoretic migration of this macro-CK type 2 was generally cathodic to CK-MM. We observed this type in severely ill patients, frequently those suffering from malignant tumors. Clinical observations and biochemical data suggest that macro-CK type 2 is of mitochondrial origin.
Gas-chromatographic determination of verapamil and norverapamil, with a nitrogen-selective detector.
Authors: Vasiliades J , Wilkerson K , Ellul D , Anticoli M , Rocchini A P 
Published: January 2020

Abstract
We present a procedure for the determination of verapamil and its metabolite, norverapamil, in serum. The drugs are extracted under basic conditions into n-heptane/2-butanol (96/4 by vol) and then extracted again into 1 mol/L H2SO4. The acidic solution is made basic with sodium hydroxide, re-extracted with diethyl ether, and the extract evaporated. The residue is redissolved in ethanol and analyzed by gas chromatography with a nitrogen-selective detector. By use of two internal standards, prazepam and D-517 (a verapamil analog), concentration and instrument response are linearly related from 50 micrograms/L to 5 mg/L. Within-run precision (CV) was 3 and 5% for both verapamil and norverapamil at concentrations of 100 and 250 micrograms/L; between-run precision was 11 and 9% at those respective concentrations. Interference studies indicate that most commonly prescribed basic drugs will not interfere with this procedure.
Simultaneous fluorometry of urinary dopamine, norepinephrine, and epinephrine compared with liquid chromatography with electrochemical detection.
Authors: Oka K , Sekiya M , Osada H , Fujita K , Kato T , Nagatsu T 
Published: January 2020

Abstract
A simple fluorometric method is described for simultaneous assay of urinary norepinephrine, epinephrine, and dopamine. The catecholamines are separated by boric acid gel chromatography and subsequently determined by use of a modified trihydroxyindole reaction. By the separation with boric acid gel, dopa can be eliminated, which interferes with dopamine measurement; consequently, the reaction is specific for catecholamines. This simple, rapid method was applied to urine specimens from normal adults. Values for urinary dopamine, norepinephrine, and epinephrine agreed with those obtained by "high-performance" liquid chromatography with electrochemical detection.
Danazol and its principal metabolites interfere with binding of testosterone, cortisol, and thyroxin by plasma proteins.
Authors: Haning R V , Carlson I H , Cortes J , Nolten W E , Meier S 
Published: January 2020

Abstract
Danazol and its three principal metabolites (2-hydroxy-methylethisterone, 2-hydroxymethyl-1,2-dehydroethisterone, and ethisterone) competitively displace cortisol and testosterone from plasma proteins. This effect is in addition to the reported inhibition of the production of testosterone-binding globulin and thyroxin-binding globulin. We saw no competitive inhibition of thyroxin binding. Concentrations of total testosterone, total cortisol, and total thyroxin were low, whereas percentages of free testosterone, free cortisol, and free thyroxin were abnormally high in women being treated with danazol. Values for testosterone, cortisol, and thyroxin in danazol-treated patients should therefore be appropriately corrected before interpretation. Protein-binding assays for testosterone or cortisol that involve testosterone- or cortisol-binding globulin may be invalid in danazol-treated subjects because of the competitive binding of danazol and its metabolites to these proteins.
Versatile semiautomated sample processor and gamma counter to increase radioimmunoassay efficiency.
Authors: Vihko R , Bolton N , Hammond G L , Kankkunen C , Koskinen L , Martio A , Soini E , Vaintola R 
Published: January 2020

Abstract
We describe a semiautomated batch-assay system designed to increase the speed and ease of performing radioimmunoassays while maintaining good accuracy and precision. The main components are a programmable pipetting unit (sample processor) and a gamma counter capable of simultaneously counting radioactivity in 12 samples. The processor uses prearranged sets of as many as 24 disposable pipette tips, which eliminates carryover between samples, and features a horizontal shaker and magnetic stirrer; 50 different assay protocols can be selected. Batches of tubes are easily transferred from the sample processor to the incubator and centrifuge. The gamma counter is controlled by a microprocessor, which is also used for data processing. Because the system is based on discrete rather than continuous-flow analysis and because of the ease with which consecutive samples can be processed, more than one operation and several different assays can be accommodated simultaneously, which saves time considerably.
Kinetic assay of beta-hydroxybutyrate in plasma with a COBAS-BIO centrifugal analyzer.
Authors: Moore J J , Marcus M , Sax S M 
Published: January 2020

Abstract
An enzymic rate method for measuring beta-hydroxybutyrate in plasma by use of beta-hydroxybutyrate dehydrogenase (EC 1.1.1.30) was adapted to the Roche COBAS-BIO centrifugal analyzer. Optimum reagent composition and reaction conditions were determined, to provide increased sensitivity and accuracy. Use of magnesium ions increased sensitivity. Comparison of results with those of a manual enzymic endpoint method involving perchloric acid protein-free filtrates of whole blood showed excellent correlation (r = 0.996). The method has good within-run and day-to-day precision. Linearity of the standard curve extends to 5000 mumol of beta-hydroxybutyrate per liter. The assay can be completed in less than 5 min and requires 15 microL of plasma and minimal reagent volumes.
Advantages of Use of Ascorbic Acid and Sodium Lauryl Sulfate in the Microdetermination of Serum the Inorganic Phosphorus
Authors: Bingley J B , de Postiglione M D G T 
Published: January 2020

Abstract
Vol. 27
p 639: In the second paragraph of the middle column, the third sentence (et seq.) should read as follows: In the method of Chen et al. (12), modified to include SLS 1,040 mmol/L, 25 µL of serum was added to 25 µL of distilled water. To this was added 200 µL of a solution of SLS containing 1040 mmol/L, followed, after mixing, by 2.50 mL of a reagent consisting of 3.1 g of ammonium molybdate per liter of 375 mmol/L sulfuric acid. To avoid any instability in the reducing capacity of ascorbic acid if mixed in advance with molybdate and sulfuric acid (14), we added it separately—0.200 mL of a 150 g/L solution in glass-distilled water. After incubation in a warm bath at 37 °C for 140 min (12), the replicated stoppered samples were cooled and their absorbances (820 nm, 1-cm cells) read immediately and 3 and 18 hlater. In those cases where SLS was not used—i.e., in the unmodified method (12)—50 µL of a prepared trichloroacetic acid extract, equivalent to 25 µL of serum, was analyzed in the same manner; 200 µL of distilled water then replaced the SLS.
p 1401: In footnote 1, the compound should read N1-(α,α-dimethyl - β - hydroxyethyl) - 2- methyl - 1,2- propanediamine.
p 1749: In Table 3, column 4, row 2: "0-20" should read "0-2.0."
p 1948: In ref. 12, "Sud-" should read "Sul-" (publication is in Portugese, not Spanish).
p 1952: The names of two of the authors are misspelled: Cassani and Vanzetti. The correct spellings in the address are "Granda" and "Niguarda."
Vol. 28
p 156: In Table 1, last column, delete "x" from the equations "y = 0.75x" and "y = 1.71x."
p 401: In the address in the middle column, "State" should read "Safe."
p 406: Third column, under "Natelson Award," Normal should read Norman.
p 557: Just before the last sentence in the second paragraph in the middle column, insert the following sentence: "The exact degree of the enhancement depends highly on the amount of catalase impurity in the glucose oxidase preparation."
A simple method of eluting proteins from two-dimensional gels.
Authors: Guevara J , Chiocca E A , Clayton F C , von Eschenbach A C , Edwards J J 
Published: January 2020

Abstract
Apo A-I lipoprotein was extracted from the appropriate pieces of two-dimensional gel patterns, by electrophoresis onto hydroxylapatite overlaying a slab of polyacrylamide sodium dodecyl sulfate gel. The extracted protein was then eluted from the hydroxylapatite by washing with increasing concentrations of phosphate buffer. The recovered protein was electrophoretically homogeneous. We believe that this method can be generally useful in the purification, for study, of proteins identified on two-dimensional gels as putative markers of disease.
Enhancement techniques for detecting trace and fluid-specific components in two-dimensional electrophoresis patterns.
Authors: Dermer G B , Silverman L M , Chapman J F 
Published: January 2020

Abstract
Albumin and other serum-derived proteins were removed from several types of body fluids by affinity chromatography, to facilitate detection of trace or non-serum-derived proteins in two-dimensional electrophoresis patterns. Albumin was removed by the dye Cibacron Blue F3G-A coupled to Sepharose. Two-dimensional patterns of albumin-depleted serum lack the large albumin spot, and several families of spots become visible that ordinarily are partly or totally hidden by it. However, other proteins also bind to Cibacron Blue. Most serum proteins, including albumin, were effectively removed by anti-human serum antibodies coupled to Sepharose. Two-dimensional patterns of serum-depleted cerebrospinal fluid exhibit five clusters of probable nervous-system protein families not detected in serum. One additional family, probably antigenically related to transferrin, was removed by the affinity step. Two-dimensional patterns of serum-depleted prostatic fluid exhibit five major non-serum families, two of which may be creatine kinase B subunits and prostatic acid phosphatase. Two-dimensional patterns of serum-depleted malignant effusions exhibit one or more of three proteins that possibly are tumor products. Pattern matching suggests the presence of one non-serum-derived protein family common to cerebrospinal fluid, prostatic fluid, and malignant effusions. Prostatic fluid and malignant effusions have in common as many as three non-serum families of proteins.
Two-dimensional gel electrophoresis of human brain proteins. II. Specific proteins and brain subfractions.
Authors: Comings D E , Carraway N G , Pekkula-Flagan A 
Published: January 2020

Abstract
Brain proteins extractable with distilled water or 9 mol/L urea were subjected to two-dimensional gel electrophoresis. They are examined in relation to the identification of actin, tubulin, neurofilament proteins, glial fibrillary acidic protein; proteins of human embryonic neocortex, synaptosomes, myelin, and plasma; and rat neocortex, rat glial, and mouse neuroblastoma cell lines.
Two-dimensional gel electrophoresis of human brain proteins. V. Non-equilibrium gel electrophoresis, with detection of a myelin basic protein mutation--MBL-Duarte.
Authors: Comings D E , Pekkula-Flagan A 
Published: January 2020

Abstract
To examine the basic human brain proteins, we subjected 9 mmol/L urea extracts to non-equilibrium gel electrophoresis. The pattern observed differs distinctly from that with equilibrium gel electrophoresis. With this technique, the myelin proteins (myelin basic protein, proteolipids, and basic Wolfgram proteins) and many other unindentified major basic proteins can be demonstrated. The myelin basic proteins occur as two major polypeptides of different charge and slightly different molecular mass, indicating the action of at least two genes. The proteolipid proteins occur as a long series of charge isomers, suggesting multiple genes or extensive post-transcriptional modification. In one patient with schizophrenia, a charge-change mutation of the larger myelin basic protein (MBL) was observed and is termed "MBL-Duarte."
A normalized protein map of human plasma, and characterization of the normalized spots by microscale amino acid analysis.
Authors: Manabe T , Kojima K , Jitzukawa S , Hoshino T , Okuyama T 
Published: January 2020

Abstract
A "normalized map" of human plasma proteins, which shows the standard distribution pattern of the proteins separated two-dimensionally in the absence of denaturing agents, is described. The pI and molecular mass of the protein represented by each spot in the normalized map are shown, and 84 of 128 spots are identified or tentatively identified as known plasma proteins. Of the several methods we used for the identification, the method of micro-scale amino acid analysis of the proteins extracted from the fixed, stained two-dimensional gels is described in detail. Patterns for human cerebrospinal fluid and urinary proteins are compared with the normalized map, the positions of proteins characteristic of each body fluid sample being shown.
Human proteins sensitive to neoplastic transformation in cultured epithelial and fibroblast cells.
Authors: Bravo R , Celis J E 
Published: January 2020

Abstract
We resolved the [35S]methionine polypeptides synthesized by normal [lung fibroblasts (WI-38), amnion cells] and transformed [SV40 transformed WI-38, AMA (spontaneously transformed amnion cells)] cultured human cells, using two-dimensional gel electrophoresis under conditions in which about 1300 polypeptides could be reproducibly separated. These studies demonstrated important changes in the relative proportions of several polypeptides that are present both in normal and transformed cells. Of a total of 400 common polypeptides that we quantitated for each cell type, 53 (22 basic and 31 acidic) varied by 40% of more in both cell pairs. Among these, we have identified vimentin (IEF 26), cyclin (IEF 49), and a tropomyosin-related polypeptide (IEF 52). No new major polypeptide was detected in the transformed cells, at least at the level of resolution currently achieved by this technique. Similar but qualitative studies of [32P]orthophosphate-labeled proteins revealed that, of 250 analyzed, only seven common phosphoproteins, including phosphovimentin (IEF 26e), varied consistently in both cell pairs. These results strengthen our previous conclusion that transformation results in changes in the relative proportions of polypeptides synthesized in normal and transformed cells rather than in the appearance of new polypeptides in transformed cells.