bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lactate production by aerobic bacteria grown in cerebrospinal fluid.
Authors: Kiechle F L , Kamela M A , Starnes R W 
Published: January 2020

Abstract
The source of the abnormally high concentration of lactate in the cerebrospinal fluid in patients with bacterial meningitis is not known. It may represent a bacterial metabolite. To determine whether cerebrospinal fluid possesses appropriate substrates to support the growth of pathogenic aerobic bacteria, three Gram-positive and nine Gram-negative bacteria were separately inoculated in pooled normal cerebrospinal fluid. After incubation for 24 h, all Gram-positive bacteria increased lactate, eight Gram-negative bacteria decreased lactate, and one Gram-negative bacteria failed to significantly change the lactate concentration. We conclude that lactate produced in cerebrospinal fluid in patients with aerobic bacterial meningitis is not necessarily a bacterial metabolite.
Two-dimensional electrophoresis of proteins from cultured human retinal-pigment epithelial cells: internal references, cataloging, and glycoproteins.
Authors: Haley J E , Gouras P 
Published: January 2020

Abstract
Two-dimensional gel electrophoresis of acidic and basic [35S]methionine-labeled polypeptides derived from primary cultures of human retinal-pigment epithelial cells revealed about 850 proteins. By co-electrophoresis with highly purified, evolutionally conserved proteins, alpha-actinin, calmodulin, cytosol retinal-binding protein, alpha- and beta-tubulin, and vinculin (mass: 130 000 Da) were tentatively identified in the fluorograms. Quantification of greater than 100 of the excised radioactive spots by liquid scintillation counting revealed an estimated overall gel/gel and donor/donor variation of 40% (SEM, 21%), the latter for data on three to four donors 57 to 81 years old. Therefore, for a difference from normal to be significant (p less than or equal to 0.01), it would, on average, have to exceed 88% of the control mean for that protein. Putative glycoproteins were independently radiolabeled, with tritiated sugars as precursors. Glucosamine was incorporated most rapidly and with the highest specific activity. It labeled about 170 polypeptides. Fucose and N-acetylmannosamine, respectively, labeled 74 and 27 polypeptides. The glycoprotein label was maximal in about 16 very acidic proteins with apparent molecular masses between 50 000 and 150 000 Da. Parallel use of both a sugar and an amino acid label facilitates identification of proteins in two-dimensional gels.
Quantitative analysis and pattern recognition of two-dimensional electrophoresis gels.
Authors: Ridder G , VonBargen E , Burgard D , Pickrum H , Williams E 
Published: January 2020

Abstract
We describe a system, both hardware and software, that provides quantitative analysis and data reduction of two-dimensional electrophoresis gels. Image-analysis techniques are used to determine spot intensities and to match spot patterns among many gels. A pattern-recognition program is used to extract the useful information contained in the spot lists. The application of this technology to a study of supernates from bacterial cultures is described.
A metrological study of autoradiographs from two-dimensional gel electrophoresis.
Authors: Valiron O , Lefkovits I , Garderet P , Steinberg C 
Published: January 2020

Abstract
Samples prepared from a single batch of labeled cells were subjected to two-dimensional gel electrophoresis and autoradiography. Three factors were varied: total quantity of protein, quantity of labeled protein, and exposure time. The mean background absorbance of the film remained identical (about 0.5 A) for all the treated series, whatever the exposure time and whether or not there were unlabeled proteins in the sample. Hence any spot with a peak A of the same order of magnitude can be seen. The standard deviation was about 0.05 A. Thus, the measurement precision is 2.5% of full scale for digitalization over 0 to 2 A. We derived experimental calibration curves, which are neither linear nor logarithmic because of the film response and which can be used on randomly chosen spots.
An approach to molecular analysis of T-cell clones by two-dimensional gel electrophoresis: is there interclonal and intraclonal heterogeneity?
Authors: Kettman J , Lefkovits I 
Published: January 2020

Abstract
To understand the regulation of immunity one must understand the processes and the consequences of the activation of the lymphoid cell, its clonal proliferation, and the ultimate differentiation of the progeny into the effector elements that constitute the immune system. By use of polyclonal mitogens, individual T-cell precursors can be activated for study of their clonal growth and generation of T effector cells. We used two-dimensional gel electrophoresis to study the gene products expressed by such T-cell clones. On comparing the radiofluorograms of such gels for a large set of T-cell clones we find that many gene products are expressed in common, as expected, but that another large set of products varies from one clone to the other and might be designated as markers of T-cell subsets or stages of differentiation. By subdividing the growing clone and analyzing the family of daughter clones, we find considerable variation in gene expression during clonal expansion.
Identification of coordinate pairs of polypeptides: a technique for screening of putative precursor product pairs in 2D gels.
Authors: Lemkin P F , Sonderegger P , Lipkin L E 
Published: January 2020

Abstract
Two-dimensional electrophoresis, combined with computerized quantification of individual proteins, provides a sensitive and accurate approach to detection of small differences in the protein pattern. As an extension of "GELLAB," a data base system for the analysis of two-dimensional electrophoretic gels, we report here on a screening algorithm for detection of certain post-translational modification events. It is based on the assumption that, if there is a post-translational modification of a protein in the transition between two functional states of a biological system, in many cases the sum of the protein concentration of a precursor-product pair in one is equivalent to that in the other. In addition to the identification of candidate pairs with a precursor-product relationship, cues to the nature of the post-translational modification that might relate them might also be derived from comparisons of the isoelectric point and apparent molecular mass. This subset of the GELLAB system may be thought of as a screening tool in the search for and investigation of post-translational protein-processing events so that the more time-consuming structural investigations to follow can be performed on a smaller set of proteins.
Quality control and technical outcome of ISO-DALT two-dimensional electrophoresis in a clinical laboratory setting.
Authors: Daufeldt J A , Harrison H H 
Published: January 2020

Abstract
In this paper, we present initial quality-control evaluations for a prototype clinical laboratory, recommendations for clinical and technical data record-keeping, and laboratory protocols designed to minimize operator-dependent analytical error in a multi-user environment. These evaluations and recommendations are based on qualitative and semiquantitative two-dimensional electrophoresis studies of the College of American Pathologists' Reference Preparation for Serum Proteins (RPSP). We include the schematic map of RPSP and manually derived estimates of analytical precision for within-run and run-to-run performance with the standard 18 X 18 cm ISO-DALT system.
Improved record keeping and photography of silver-stained two-dimensional electrophoretograms by way of "XRD images".
Authors: Harrison H H 
Published: January 2020

Abstract
Kodak X-Ray Duplication film provides a relatively simple and inexpensive medium for producing full-size positive-image transparencies ("XRD images") from silver-stained two-dimensional polyacrylamide gel electrophoretograms. In these XRD images, the spot or band pattern of a polychromatic silver-stained gel is represented as black against a clear background, regardless of the color of the spot in the gel itself. Thus, XRD images may be overlapped with transillumination for visual gel-to-gel comparisons, may be easily subjected to scanning densitometry, and may have the exposure adjusted to provide the proper background for black-and-white photography. I describe here the details of the XRD method and the design of a new apparatus for producing XRD images in a wet-gel "contact-print" format, which improves the method.
Proteins in normal, irradiated, and postmortem human brain quantitatively compared by using two-dimensional gel electrophoresis.
Authors: Narayan R K , Heydorn W E , Creed G J , Kornblith P L , Jacobowitz D M 
Published: January 2020

Abstract
Using a combination of two-dimensional gel electrophoresis (2DE), silver staining, and computerized densitometry, we studied protein patterns in human cerebral cortex: normal fresh-frozen, fresh-frozen but previously irradiated, and post-mortem. The relative molecular mass of the resolved proteins ranged from 14 400 to 100 000, the isoelectric points from 4.75 to 7.0. The pattern of proteins (six of them identified) was essentially the same for all three groups. However, computerized densitometry demonstrated significant alterations in the density of several spots in the irradiated and postmortem groups as compared with the normal controls. Irradiated cortex showed statistically significant changes in only six spots (three increased and three decreased in density); postmortem material showed 20 altered spots (16 diminished and four increased). Evidently normal human cerebral cortex has a consistent protein pattern on 2DE, which is quantitatively (but not qualitatively) altered in irradiated and postmortem material. These findings provide a point of reference against which proteins from abnormal brain material can be compared, both qualitatively and quantitatively.
Two-dimensional gel electrophoresis used in neurobiological studies of proteins in discrete areas of the rat brain.
Authors: Jacobowitz D M , Heydorn W E 
Published: January 2020

Abstract
Using two-dimensional gel electrophoresis, we studied proteins in the rat brain. The relative amounts of individual proteins differ in discrete areas of the brain, and the concentrations of three different proteins can be altered by chronic administration of desmethylimipramine or reserpine. Brain proteins can be radiolabeled in vitro by incubating samples of fresh tissue with [35S]methionine. We identified several proteins by using immunoblotting and comigration. Finally, we developed a possible animal model for studying proteins related to Alzheimer's disease by depleting the cholinergic innervation to the cortex and the hippocampus.
Gamma heavy chain disease studied by two-dimensional electrophoresis and immuno-blotting techniques.
Authors: Blangarin P , Deviller P , Kindbeiter K , Madjar J J 
Published: January 2020

Abstract
We used two-dimensional polyacrylamide gel electrophoresis and immunoblotting techniques to study serum proteins from a patient with a monoclonal gammopathy. Two-dimensional electrophoresis was optimized for serum proteins with two main goals: (a) to allow the resolution of many serum proteins in both directions, with penetration of the maximum number of proteins in the first dimension; and (b) to obtain the best reproducibility from one experiment to another, within the limits of the current technique. These analyses, combined with immunoblotting, permitted us to characterize a gamma heavy chain disease protein of 34 000-Da molecular mass. Moreover, two-dimensional mapping of the patient's serum proteins allowed demonstration of the microheterogeneity of this monoclonal component.
Systematic characterization of human prostatic fluid proteins with two-dimensional electrophoresis.
Authors: Tsai Y C , Harrison H H , Lee C , Daufeldt J A , Oliver L , Grayhack J T 
Published: January 2020

Abstract
We present a systematic analysis of human prostatic fluid with two-dimensional gel electrophoresis (the ISO-DALT system) and a characterization of normal and disease-related protein patterns. A reference map for prostatic fluid proteins was established by analysis of pooled prostatic fluids from 80 men (age less than or equal to 50 years) without prostatic lesions. Proteins in prostatic fluid that share immunogenicity with serum proteins were identified by use of antibody to whole human-serum protein in an affinity-column fractionation of a reference pool and differential analysis of the absorbed (serum components) and unabsorbed (non-serum components) fractions. Individual prostatic fluids from 30 patients (eight with prostatic cancer, 10 with prostatitis and benign prostatic hyperplasia, six with benign prostatic hyperplasia alone, and six with asymptomatic chronic prostatitis) were scored qualitatively with respect to the presence or absence of 57 major prostatic fluid proteins. Statistically significant, disease-correlated alterations were observed for at least eight of the proteins so scored.
Global approaches to quantitative analysis of gene-expression patterns observed by use of two-dimensional gel electrophoresis.
Authors: Anderson N L , Hofmann J P , Gemmell A , Taylor J 
Published: January 2020

Abstract
A major difficulty in the use of two-dimensional protein maps to identify and classify cell types is the problem of acquiring, selecting, and analyzing quantitative data on hundreds of protein spots. Here we use methods of multivariate statistics to analyze the differences among a panel of human cell lines, in some cases involving quantitative data on more than 250 proteins. Principal-component and cluster-analysis techniques show that the lines can be easily distinguished, even by using the subset of proteins present in all cells. A preliminary analysis of the protein changes brought about by phorbol ester-induced differentiation of the line U937 is included.
"Map" of proteins resolved from human chorionic villi by two-dimensional electrophoresis.
Authors: Trnka P L , Pergament E , Anderson N G 
Published: January 2020

Abstract
Two-dimensional electrophoresis was applied to specimens of human chorionic villi obtained during the first trimester of gestation, the object being to simultaneously map several hundred polypeptide gene products. Genetically normal specimens were homogenized in a urea-based denaturant and the supernates were electrophoresed with use of the "ISO-DALT" system. Four categories of proteins are distinguished on the map: previously identified proteins present in chorionic villi and other cell types; unidentified proteins present in chorionic villi and other cell types; proteins present in chorionic villi and amniotic fluid but not in other cell types; and proteins probably originating from the amnio-chorionic plate. The reference map for chorionic villi provided in this study may serve as the basis of determining whether genetic analyses conducted in the first trimester accurately represent the fetal genotype.
Protein changes in activated human platelets.
Authors: Giometti C S , Anderson N G 
Published: January 2020

Abstract
Using two-dimensional electrophoresis, we mapped both the total and the cytoskeletal proteins of human platelets before and after activation with thrombin or the calcium ionophore A23187. Activation resulted in increased abundance of the phosphorylated form of myosin light chains with an approximate molecular mass of 20 kDa, decreased abundance of two proteins with molecular masses of approximately 18 and 25 kDa, and, in the case of activation with thrombin, the appearance of a new chain of protein spots (named "Thromb:1"). The latter, found associated with isolated detergent-insoluble cytoskeletons, reacted with antibody to human fibrinogen and thus were identified as gamma-gamma dimers of fibrin. The total number of proteins associated with the cytoskeleton increased after activation with either thrombin or A23187, but we observed some differences in which proteins were bound, and for how long.
Concentrations of non-glucose polyols in serum and cerebrospinal fluid from apparently healthy adults and children.
Authors: Yoshioka S , Saitoh S , Seki S , Seki K 
Published: January 2020

Abstract
Six non-glucose polyols--mannose, fructose, 1-deoxyglucose, mannitol, glucitol, and inositol--were identified and evaluated in human serum and cerebrospinal fluid by gas-liquid chromatography and by gas-liquid chromatography/mass spectrometry. Concentrations of fructose, mannose, and inositol in the serum of healthy persons or children without metabolic diseases varied with age, as already reported for 1-deoxyglucose. Fructose, inositol, and glucitol concentrations in cerebrospinal fluid significantly exceeded those in serum. The method described here for determining polyols and for evaluating polyol patterns in serum, as well as the resulting data on children and healthy subjects, should be useful in investigations of the clinical and physiological significance of polyols.
Liquid-chromatographic determination of two antidepressants, trazodone and mianserin, in plasma.
Authors: Wong S H , Waugh S W , Draz M , Jain N 
Published: January 2020

Abstract
Plasma containing trazodone or mianserin was extracted. The organic phase containing trazodone was evaporated and the residue was reconstituted in dilute acid. Mianserin was back-extracted from the organic phase with dilute acid. Both drugs were chromatographed on mu Bondapak C18 columns, with phosphate/acetonitrile as the mobile phase. Peak-height ratios of drug/internal standard were linearly correlated with concentrations between 25 and 2000 micrograms/L for trazodone, and between 25 and 200 micrograms/L for mianserin, with respective between-run CVs of 4.7% and 7.6%. Detection limits were 5 ng. Of some common drugs and metabolites examined, nortriptyline co-elutes with the internal standard used in the trazodone assay, while flurazepam co-elutes with mianserin. Concentrations of trazodone in 26 patients ranged from 73 to 1678 micrograms/L. For two geriatric patients, concentrations were about 2000 micrograms/L. For two overdose patients, they were about 5000 micrograms/L. The concentration of mianserin was 27 micrograms/L for a volunteer treated with a single 40-mg oral dose.
Rapid radioimmunoassay for corticotropin in unextracted human plasma.
Authors: Nicholson W E , Davis D R , Sherrell B J , Orth D N 
Published: January 2020

Abstract
This RIA for corticotropin (ACTH) involves use of a commercially available antiserum and permits measurement of immunoreactive ACTH in unextracted plasma. The assay takes 2.5 days, detects as little as 5 pg/mL of plasma, and is specific: structurally and (or) biosynthetically related peptides do not cross react. Generally, data on dilutions of almost all human plasma specimens produce curves parallel to that for the ACTH reference standard. Values correlate well with those obtained by a well-established but more laborious RIA. We measured immunoreactive ACTH in normal subjects at various times of the day and after modulation of their pituitary-adrenal axis, and in patients with hypo- and hyper-secretion of ACTH. We conclude that the full range of immunoreactive ACTH values, which accurately reflect the status of the subject's pituitary-adrenal axis, can be quickly and easily determined in samples of unextracted human plasma.
Evaluation of a direct solid-phase radioimmunoassay for progesterone, useful for monitoring luteal function.
Authors: Kubasik N P , Hallauer G D , Brodows R G 
Published: January 2020

Abstract
We have evaluated a commercially available, direct, solid-phase radioimmunoassay kit for progesterone determination in serum or plasma. The assay is precise, within-run precision (CV) in the clinically significant ranges being 2.5 to 5.2%, between-run 5.5 to 5.8%. Mean analytical recovery of different concentrations of progesterone added to serum was 99.7% (range 95.3 to 102.7%). Fourteen closely related steroids showed no cross reactivity. The minimum detection limit was 0.5 microgram/L. Luteal-phase progesterone concentrations in serum were increased (greater than 3 micrograms/L) in 19 normal ovulatory menstrual cycles and decreased (less than 1.5 micrograms/L) in two nonovulatory cycles. We found this direct assay for progesterone to be analytically and clinically sound, and useful for assessing luteal-phase function.
Dual-channel continuous-flow system for determination of phenylalanine and galactose: application to newborn screening.
Authors: Hoffman G L , Laessig R H , Hassemer D J , Makowski E R 
Published: January 2020

Abstract
We describe a dual-channel AutoAnalyzer (Technicon) system for the simultaneous measurement of phenylalanine and galactose from blood specimens on filter-paper. Using a single 1/4-in.-diameter (6-mm) specimen, we measure both components fluorometrically at a rate of 70/h. Analytical recovery with the method and the linearity of measurements vs sample concentration are excellent through the ranges of interest, 0-200 mg/L for phenylalanine and 0-800 mg/L for galactose. Carryover at the critical values during screening, 40 mg/L for phenylalanine and 100 mg/L for galactose, is essentially zero. The dual-channel system provides the means to incorporate a low-incidence test, i.e., galactosemia (incidence 1/70 000), into an existing program for phenylalanine analysis, for which the higher rates (phenylketonuria, incidence 1/11 500) easily justify the cost of mass screening.
Simple method for preparing and quantifying very-low-density lipoprotein.
Authors: Kohlmeier M 
Published: January 2020

Abstract
A micromethod is described for isolating and quantifying human very-low-density lipoprotein (VLDL) from 0.1 mL of human serum, by which more than 100 samples can be processed in half a day with a standard ultracentrifuge. Replicate analysis of 10 normal and hyperlipemic samples gave median coefficients of variation of 11.7% for VLDL cholesterol, 5.1% for VLDL triglycerides. Results obtained by micro-ultracentrifugation and enzymic cholesterol measurement agreed closely with those measured with an electrophoretic method (Pearson's r = 0.98). Compared with the established method, on the other hand, lower values were found for both VLDL cholesterol (r = 0.89) and triglycerides (r = 0.97).
Effect of pH and NaCl on measurements of ionized calcium in matrices of serum and human albumin with a new calcium-selective electrode.
Authors: Rehfeld S J , Barkeley J , Loken H F 
Published: January 2020

Abstract
A neutral ligand ion-exchanger type of ion-selective electrode is used in the current version of the Orion Model SS-20 calcium analyzer. We evaluated it over the pH range 4.0 to 8.5, using albumin solutions containing 150 mmol/L NaCl and pooled patients' serum. Within this pH range response was nernstian, and the relationship between potential (in millivolts) and log [Ca2+] at each pH was linear. Variation in Ca2+ with increasing ionic strength (because of added NaCl) was not significantly different between standards and albumin solutions; it decreased in both. In contrast, the proportion of calcium in serum increased with increasing NaCl concentrations. Ca2+ was not bound in whole serum albumin at a pH less than about 3.9. We observed a substantial difference between the degree of Ca2+ binding in solutions of fatty-acid-free human albumin and serum.
A comment on thyrotropin measurement and evaluation.
Authors: Musto J D , Pizzolante J M , Chesarone V P 
Published: January 2020

Abstract
There is a need for improvement of thyrotropin measurements in the clinical laboratory, specifically in the lower portion of the normal range. We cite realistic examples of incorrect, misleading data generated with many thyrotropin kits currently in use and propose a practical laboratory protocol to evaluate the performance of a procedure for determining thyrotropin. The protocol integrates medical physiology with analytical measurement.