bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid-chromatographic assay for retinol (vitamin A) and retinol analogs in therapeutic trials.
Authors: McClean S W , Ruddel M E , Gross E G , DeGiovanna J J , Peck G L 
Published: January 2020

Abstract
A "high-performance" liquid-chromatographic separation of retinoids (retinol, isotretinoin, all-trans retinoic acid, retinal, etretinate, and retinyl acetate) in serum is described. The separation was used in developing a quantitative assay for retinol (vitamin A) and two therapeutic analogs, isotretinoin (13-cis-retinoic acid) and etretinate (Ro 10-9359). The procedure requires 1 mL of serum. Overall analytical recovery for retinol, isotretinoin, and etretinate from serum was 100% (SD 7%). The between-day coefficient of variation for specimens with concentrations ranging from 0.70 to 0.95 mg/L was less than 4%. Normal reference intervals for serum retinol in men and women are 0.61 to 1.33 and 0.44 to 1.19 mg/L, respectively.
A new chromogenic amylase method compared with two established methods.
Authors: Fenton J , Foery R , Piatt L , Geschwindt K 
Published: January 2020

Abstract
We tested a new amylase reagent involving chromogenic substrates (Pantrak, Calbiochem-Behring) for precision, dynamic range, and susceptibility to potential interferences. Two p-nitrophenyl-alpha-maltaosides are used as substrates, which amylase cleaves to shorter-chain p-nitrophenyl maltaosides, the latter then yielding p-nitrophenol from the activity of alpha-glucosidase. A series of 100 specimens were tested by Pantrak and two established methodologies. In both cases, correlation was excellent. Precision was good for all methods; CVs for Pantrak were 3.0 to 4.5%. The dynamic range of Pantrak extended to 800 U/L. Above-normal quantities of triglyceride, hemoglobin, or bilirubin did not cause spurious results, but anticoagulants that bind divalent cations should not be used. The Pantrak method has desirable analytical features and is easy to use.
How many proteins are there in a typical mammalian cell?
Authors: Duncan R , McConkey E H 
Published: January 2020

Abstract
There is a major disparity between the number of polysomal mRNA species found in mammalian cells and the number of polypeptides detected by high-resolution two-dimensional polyacrylamide gel electrophoresis. Here we show that technical factors are not responsible for the relative paucity of proteins, and that the translation products of rare mRNAs would be easily detectable if all mRNAs were translated in proportion to their abundance. We conclude that a large majority of rare mRNAs are translated at no more than a tenth the average translation rate, if they are translated at all. There may be no more than 2000 physiologically significant primary gene products (polypeptides) in a typical mammalian cell.
Two-dimensional gel electrophoresis of human brain proteins. I. Technique and nomenclature of proteins.
Authors: Comings D E 
Published: January 2020

Abstract
To understand at a molecular level the basis of the normal and pathological genetic differences between individuals it is necessary to begin a detailed two-dimensional gel electrophoretic mapping of the proteins of the human brain in normal individuals and those with various genetic neurological disorders. The present study is an examination of the polypeptide patterns of extracts of the human brain made with 9 mol/L urea solution. Details of the technique and the nomenclature of the patterns obtained are presented. the gels are separated into 20 sub-sections, based on standards with known molecular masses and isoelectric points. Groups of polypeptides within these sub-sections are identified by a number and a letter; the individual proteins are identified by a number. Thus, protein 1 in subsection 8, group b, would be designated 8b: 1. Subsequent papers in this series identify many of these proteins; show which proteins belong to the cytosol, synaptosome, myelin, and other brain fractions; show how these patterns vary between normal individuals and those with different neurological and psychiatric conditions; examine the effect of severe gliosis; and present the results of non-equilibrium gel electrophoresis for the more basic proteins.
Microscale multisample two-dimensional electrophoresis of proteins in human serum, cerebrospinal fluid, and urine.
Authors: Manabe T , Hayama E , Okuyama T 
Published: January 2020

Abstract
In this technique, in which no denaturing agent is used, proteins in human serum, cerebrospinal fluid, and urine are separated by isoelectric focusing in cylindrical 40 g/L polyacrylamide gels of capillary size (1.3 x 35 mm) for 40 min, followed by electrophoresis in 40--170 g/L polyacrylamide linear gradient gel, with use of 38 x 35 x 1 mm slab gel, for 1 h. Only 2 microL of untreated human serum is required to obtain clear protein-distribution patterns, made visible by Coomassie Blue staining. By use of silver staining, proteins in unconcentrated cerebrospinal fluid can be made visible. An apparatus we devised for microscale two-dimensional electrophoresis enables us to analyze eight protein samples simultaneously.
A two-dimensional gel analysis of autologous T and B lymphoblastoid cell lines.
Authors: Lester E P , Lemkin P , Lipkin L 
Published: January 2020

Abstract
We sought polypeptide markers of pathways of lymphoid differentiation by comparing the protein-synthesis patterns of a pair of autologous human lymphoblastoid cell lines: the B-cell line CCRF-SB and the T-cell line CCRF-HSB-2. Cells were cultured in standard medium for 24 or 120 h, then biosynthetically radiolabeled with [3H]leucine. Whole cell lysates were subjected to two-dimensional gel electrophoresis and patterns of protein synthesis were made visible by fluorography. Replicate cultures showed highly reproducible patterns, but differing culture durations produced alterations in the relative synthetic rates of some proteins. Protein synthetic patterns were analyzed visually and with the GELLAB system for computer analysis of two-dimensional gel images. Qualitative and quantitative differences were found between the T- and B-cell patterns. GELLAB detected and accurately paired most of the well-defined spots in each image and constructed a unified data base from data on our initial gels. Statistical analysis of this data revealed several marker proteins, the relative synthetic rates serving to distinguish the T-cell line from the B-cell line. Such computerized analysis of protein synthetic patterns of malignant cells appears likely ultimately to provide important diagnostic information regarding human malignancies.
Design and implementation of a prototype Human Protein Index.
Authors: Taylor J , Anderson N L , Scandora A E , Willard K E , Anderson N G 
Published: January 2020

Abstract
This paper describes information-handling aspects of the TYCHO I analysis system (Clin, Chem. 27: 1807--1820, 1981), which analyzes two-dimensional electrophoresis gels, matches the individual protein spots with those in a reference pattern, and stores various information--including spot measurements, identifications, treatment profiles, set memberships, and comments--in a computerized database. This and additional information such as amino acid composition and cellular localization is then accessible from an interactive program that includes a pictorial user interface and presents much of the data in graphical form. Use of the TYCHO I system is illustrated by examples drawn from analyses of gel patterns from human leukocytes.
Clinical applications of two-dimensional electrophoresis.
Authors: Jellum E , Thorsrud A K 
Published: January 2020

Abstract
High-resolution two-dimensional electrophoresis has been used in our institute to study sera from patients with multiple myelomas; cerebrospinal fluid from patients with different neurological disorders; blister fluid, dermis, and epidermis from patients with skin diseases; and biopsies from brain tumors; and to search for tumor-associated proteins in cancer biopsies and pre-cancer sera. The method differentiates between all main types of immunoglobulins and gives rise to protein patterns for cerebrospinal fluid that may carry diagnostic information. The pattern of proteins in serum and blister fluid is almost identical, confirming that the latter is a filtrate of serum. We also analyzed sera collected from patients several years before it was clinically recognized that they had cancer (JANUS serum bank), in an attempt to find tumor-associated proteins in serum at an early stage of the disease. We encountered difficulties in detecting trace proteins, due to masking effects of such major serum-protein constituents as albumin. A combination of computerized gas chromatography-mass spectrometry and high-resolution two-dimensional electrophoresis is capable of mapping compounds of both low and high molecular mass. Used in combination with pattern-recognition analysis, the complete multicomponent analytical system opens the possibility of diagnosing diseased cells solely on the basis of differences in their biochemical composition.
Demonstration of basic human-brain-specific proteins by the BASO-DALT system.
Authors: Jackson P , Thomson V M , Thompson R J 
Published: January 2020

Abstract
We used the BASODALT system (Cell 12: 1133--1142, 1977) of high-resolution two-dimensional gel electrophoresis to resolve proteins in extracts of human brain and, for comparison, those in nine other human organs. At least 180 protein-staining spots are visible on a BASODALT electrophoretogram of water-soluble human brain proteins. By electrophoresing extracts of different human organs, separately and mixed with brain extract, we could detect 14 basic spots that appear to be present in brain in concentrations at least 20-fold those in any other organ. Measurement of these new basic brain-predominant proteins may provide useful diagnostic information in neurological disorders.
Some relatively simple steps toward a computer system for the analysis of two-dimensional gel-electrophoresis autoradiographs.
Authors: Fox S H 
Published: January 2020

Abstract
A computerized system for the quantitative comparison of two-dimensional polyacrylamide gel autoradiographs is being developed that requires relatively limited hardware resources. Two fast, simple, and stable programs--one for background and streak subtraction and one for peak detection--have been developed and tested. Two methods developed by others--one for image smoothing and one for peak matching--also have been tested. A very simple spot-density integration program that works on isolated spots has been written and is being developed further.
Cytoskeletal proteins from human skin fibroblasts, peripheral blood leukocytes, and a lymphoblastoid cell line compared by two-dimensional gel electrophoresis.
Authors: Giometti C S , Willard K E , Anderson N L 
Published: January 2020

Abstract
Differences in proteins between cells grown as suspension cultures and those grown as attached cultures were studied by comparing the proteins of detergent-resistant cytoskeletons prepared from peripheral blood leukocytes and a lymphoblastoid cell line (GM607) (both grown as suspension cultures) and those of human skin fibroblasts (grown as attached cultures) by two-dimensional gel electrophoresis. The major cytoskeletal proteins of the leukocytes were also present in the protein pattern of GM607 cytoskeletons. In contrast, the fibroblast cytoskeletal protein pattern contained four groups of proteins that differed from the patterns of the leukocytes and GM607. Three groups (Cytoskf:8--10, :14--16, and :17--18) showed qualitative differences, and the fourth group (Cytoskf:11 and :13) showed quantitative differences. In addition, surface labeling of GM607 and human fibroblasts with 125I demonstrated that substantial amounts of vimentin and actin are exposed at the surface of the attached fibroblasts, but there is little evidence of similar exposure at the surface of the suspension-grown GM607. Cytoskf:11 and :13 in fibroblast preparations were also labeled with the 125I. These results demonstrate some differences in cytoskeletal protein composition between different types of cells could be related to their ability or lack of ability to grow as attached cells in tissue culture.
Computer programs for adapting two-dimensional gels to the study of mutation.
Authors: Skolnick M M , Sternberg S R , Neel J V 
Published: January 2020

Abstract
We are attempting to adapt the two-dimensional polyacrylamide gel technology to the search for mutations that after the electrophoretic mobility of proteins. These events are expected to have a frequency on the order of 10(-6). To this end, programs that run on the CytocomputerTM are being developed for comparing the pattern of the gel derived from a child's blood sample with those of the gels of corresponding samples from its parents. We anticipate examining thousands of such trios. Programs are described that perform background normalization, noise filtering, spot detection, gel registration, and, finally, compare the father/mother/child gel trios for the presence of unique protein moieties in the child that are consistent with a mutational event.
An approach to completely automatic comparison of two-dimensional electrophoresis gels.
Authors: Skolnick M M 
Published: January 2020

Abstract
The problem addressed is that of determining the similarities and differences appearing in a sequence of two-dimensional polyacrylamide gels where we have no a priori knowledge of the intensity and spatial distribution of the protein spots. It is assumed that the gels are not in precise registration. An attempt is being made to develop a completely automatic program for use in genetic studies, which will compare a sequence of three gels run on samples from father, mother, and child. The program constructs a graph by using as nodes those spot cues that exceed a given intensity threshold. The graphs are then compared to determine an initial subset of spots that are common to all three gels. From this subset of common spots the program then determines whether the remaining graph differences are real or result from quantitative variation causing spots to fall below threshold.
Latex immunoassay of retinol-binding protein.
Authors: Bernard A M , Moreau D , Lauwerys R R 
Published: January 2020

Abstract
Latex immunoassay, a sensitive method based on latex particle agglutination, is used here for the determination of retinol-binding protein in human biological fluids. The assay, similar to that described previously for beta 2-microglobulin (Clin. Chem. 27:832-837, 1981), consists of incubating the sample at 37 degrees C for 30 min with antibody-coated particles, then quantifying the resulting agglutination by particle-counting or turbidimetry. Latex particles coated with antibody are stabilized just before use by dispersing them in a solution of bovine serum albumin at pH 10. The standard curve ranges from 0.5 to 32 micrograms/L; recovery averages 102% in urine and 93.5% in serum; between- and within-assay CVs range from 5.1 to 11.7%. The correlation coefficients of latex immunoassay with rocket immunoelectrophoresis for analysis of retinol-binding protein in 26 urines and with radial immunodiffusion in 30 sera are 0.99 and 0.91, respectively. In healthy subjects, the mean urinary excretion of retinol-binding protein is 52.5 micrograms/g of creatinine (SD = 59.2 micrograms/g of creatinine; n = 150) and the concentration in serum averages 46 mg/L (SD = 10.4 mg/L, n = 22).
Rapid colorimetric assay for acetaminophen without salicylate or phenylephrine interference.
Authors: Swanson M B , Walters M I 
Published: January 2020

Abstract
A simple rapid, and economical procedure is presented for the quantitative determination of acetaminophen in serum. Acetaminophen is extracted into solvent, and, when back-extracted into base, is simultaneously reacted with Folin-Ciocalteau reagent to form a colored complex. The potential interference of bilirubin is eliminated by treatment with p-diazobenzene sulfonic acid. Results obtained with this method agree with those obtained by "high-pressure" liquid chromatography.
An improved procedure for detection of hypoxanthine--guanine phosphoribosyl transferase heterozygotes.
Authors: Page T , Bakay B , Nyhan W L 
Published: January 2020

Abstract
The absence of activity of the enzyme hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) is known to be the cause of the Lesch-Nyhan syndrome. Previous methods for detection of heterozygous carriers of this genetic defect either are quite time consuming, require specialized equipment, or lack the necessary sensitivity. We present here a method in which thin-layer chromatography and autoradiography are used to assay the activity of this enzyme in individual hair roots collected from the scalp of the possible carrier. This method is fast and sensitive, and requires no specialized equipment.
Use of glycerol-cryoprotected Lactobacillus casei for microbiological assay of folic acid.
Authors: Wilson S D , Horne D W 
Published: January 2020

Abstract
A simple procedure for preparing glycerol-cryoprotected Lactobacillus casei cultures has been developed. L. casei grown in medium supplemented with low concentrations of folic acid (0.3 micrograms/L) is diluted with an equal volume of glycerol (800 mL/L) and stored at -20 degrees C. Growth response of the glycerol-cryoprotected L. casei to low concentrations of folic acid exceeded that of cultures maintained by monthly agar stab transfer. Also, growth for the zero-folate blanks was considerably less for the cryoprotected cultures. Assay of folate in several rat tissues correlated well (r = 0.999) with the standard microbiological assay. The growth rate of the culture depends on the inoculum size, and a heavy inoculum of cryoprotected L. casei may be used to complete the assay after only an overnight incubation.
Improved liquid-chromatography of aspirin, salicylate, and salicyluric acid in plasma, with a modification for determining aspirin metabolites in urine.
Authors: Buskin J N , Upton R A , Williams R L 
Published: January 2020

Abstract
Detailed performance specifications are given for a specific and sensitive liquid-chromatographic assay for aspirin, salicylic acid, and salicyluric acid in plasma. The sensitivity of this method for aspirin (50 micrograms/L) is 10-fold that of previous methods, so that concentrations of aspirin in plasma can now be followed for about four or five half-lives after the peak plasma concentration arising from a single 650-mg dose. In addition, this assay is as sensitive for salicylic and salicyluric acid in plasma as any hitherto. A modification permits measurement of gentisic acid, salicylic acid, and salicyluric acid in urine; further modifications allow indirect measurement of conjugated gentisate and salicylate in urine.
Identification and metabolic implication of 1-deoxyglucose (1,5-anhydroglucitol) in human plasma.
Authors: Yoshioka S , Saitoh S , Fujisawa T , Fujimori A , Takatani O , Funabashi M 
Published: January 2020

Abstract
1-Deoxyglucose (1,5-anhydroglucitol), a metabolite related to diabetes mellitus, was identified in human plasma by gas-liquid chromatography and by gas-liquid chromatography/mass spectrometry. Plasma polyols were accurately determined with a gas-liquid chromatograph equipped with an all-glass capillary column. The plasma content of 1-deoxyglucose in healthy persons varies with age. Although the precise physiological role of 1-deoxyglucose remains obscure, the method described here for determining the minor polyol components of plasma, as well as the findings of 1-deoxyglucose in the plasma of healthy subjects, may be useful for investigating the metabolic roles of 1-deoxyglucose.
Thermal-ionization isotope-dilution mass spectrometry as a definitive method for determination of potassium in serum.
Authors: Gramlich J W , Machlan L A , Brletic K A , Kelly W R 
Published: January 2020

Abstract
Thermal-ionization isotope-dilution mass spectrometry is a highly precise and accurate method for the determination of potassium concentrations in serum. Although not suited for routine use because of the time and expense required, the technique provides an extremely valuable tool for the characterization of reference materials and for evaluating other analytical methods. The technique has recently been used to determine the concentration of potassium in a human serum standard, NBS Standard Reference Material 909. Seven vials of the serum were chemically processed and then analyzed by two spectroscopists independently, using different mass spectrometers. The results confirm previous work that indicates that a precision of 0.1% relative can be routinely achieved. The systematic errors in the method have been thoroughly evaluated. When the precise results are thus corrected, they are essentially bias free and hence definitive.
Direct 125I-radioligand assays for serum progesterone compared with assays involving extraction of serum.
Authors: Ratcliffe W A , Corrie J E , Dalziel A H , Macpherson J S 
Published: January 2020

Abstract
We compared two direct radioimmunoassays for progesterone in 50 microL of unextracted serum or plasma with assays involving extraction of serum. The direct assays include the use of either danazol at pH 7.4 or 8-anilino-1-naphthalenesulfonic acid at pH 4.0 to displace progesterone from serum binding-proteins. Progesterone is then assayed by using an antiserum to a progesterone 11 alpha hemisuccinyl conjugate and the radioligand 125I-labeled progesterone 11 alpha-glucuronyl tyramine, with separation by double-antibody techniques. Direct assays with either displacing agent gave good analytical recovery of progesterone added to human serum, and progesterone values for patients' specimens correlated well (r greater than 0.96) with results of assays involving extraction of serum. Precision was similar with each displacing agent over the working range 2.5-100 nmol/L and superior to that of extraction assays. We conclude that these direct assays of progesterone are analytically valid and more robust, precise, and technically convenient than many conventional methods involving extraction of serum.
Improved assessment of plasma lipoprotein patterns. IV. Simple preparation of a lyophilized control serum containing intact human plasma lipoproteins.
Authors: Wieland H , Seidel D 
Published: January 2020

Abstract
Addition of sucrose (413-825 mmol/L) to human serum allows plasma lipoproteins to be lyophilized without denaturation. A control serum so prepared is especially suited for use in monitoring determinations of apolipoproteins and quantitative lipoprotein electrophoresis. It is clear upon reconstitution; hence, the described procedure may also be useful for preparation of control sera for general clinical chemistry without de-lipoproteinization.
Effects of Sample Freezing on Ion-Selective Electrode Determinations of Serum Calcium
Authors: Plant Sandford B , McCarron David A 
Published: January 2020

Abstract
We assessed in a prospective study the effects of freezing, thawing, and prolonged storage of serum samples for ionized calcium determinations with the "Clin ± Ion." Forty-eight serum samples were collected before and during infusions of EDTA and calcium into human subjects. Values for ionized calcium in serum samples stored frozen for one and six months were similar to those determined for fresh specimens. Samples stored for 12 months had significantly (p &lt;0.001) lower values. Thawing and refreezing the sample within the first six months did not alter values. We conclude that serum samples can be frozen and stored for as long as six months without affecting results for ionized calcium determinations.