bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radioimmunoassay of cholecystokinin in plasma.
Authors: Ohgo S , Takemura J , Oki Y , Nishizono F , Ishikawa E , Yoshimi T , Yamamura T , Seino Y , Matsukura S 
Published: January 2020

Abstract
A sensitive and specific radioimmunoassay for cholecystokinin (CCK) has been developed. Synthetic unsulfated carboxy-terminal fragment, CCK-8, was radioiodinated by the conventional Chloramine-T method. Antibodies were raised against sulfated CCK-8 covalently coupled to bovine thyroglobulin via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. By purification, highly immunoreactive 125I-labeled CCK-8 was obtained. The antiserum was highly avid, and plasma could be assayed directly. The detection limit of the assay was 5 pmol of sulfated CCK-8 per liter. The assay measured fragments CCK-8, CCK-33, and CCK-39 with equimolar potency. CCK-4, gastrin, and vasoactive intestinal polypeptide were not detected, even at higher concentrations. The concentration of CCK, as the sum of these CCK peptides, in plasma during fasting was low (10.5 +/- 2.1 pmol/L, mean +/- SEM) but still detectable in all normal subjects examined (range, 6.4-20.1 pmol/L). After ingestion of a test meal, CCK in plasma increased rapidly, peaking at 41.3 (SEM 5.7) pmol/L at 40 min and remaining high for 3 h after the meal. This supports the concept that CCK has important roles in digestion and absorption.
A computerized classification technique for screening for the presence of breath biomarkers in lung cancer.
Authors: O'Neill H J , Gordon S M , O'Neill M H , Gibbons R D , Szidon J P 
Published: January 2020

Abstract
A simple computer-based screening technique has been developed for classifying human expired air components into 16 chemical classes, based on empirical formulas. The sort procedure was developed to simplify the screening of the composition of expired air samples by sorting all components into chemical classes and classifying components at the greater than 75% and greater than 90% occurrence levels. Both occurrence-rate components are then evaluated as diagnostic markers in a discriminant function model for their ability to detect lung cancer. Of the 386 components detected in the gas chromatography/mass spectrometry (GC/MS) data files, 45 components were present at the greater than 75% occurrence level and 28 components at the greater than 90% occurrence level. Thus, this preliminary sort routine, performed by using a simple macro program installed into a standard personal-computer spread-sheet, greatly reduces the amount of data required for statistical treatment. Such a sort routine can also be applied as easily to other complex GC/MS data files for the purpose of data reduction.
Age- and sex-specific pediatric reference intervals and correlations for zinc, copper, selenium, iron, vitamins A and E, and related proteins.
Authors: Lockitch G , Halstead A C , Wadsworth L , Quigley G , Reston L , Jacobson B 
Published: January 2020

Abstract
Age- and sex-specific reference intervals based on the 0.025 and 0.975 fractiles of data derived from a healthy pediatric population are presented for zinc, copper, selenium, iron, ferritin, retinol, alpha-tocopherol, and related analytes in serum. Age was an important covariate for copper, selenium, retinol, and tocopherol, and ferritin in boys. Strong correlations were found between retinol and retinol-binding protein, prealbumin (transthyretin), alpha-tocopherol, and selenium. Tocopherol was highly correlated with both cholesterol and triglycerides. We found no relationship between serum zinc and either retinol or retinol-binding protein. Despite exclusion of children in whom anemia, microcytosis, or variant hemoglobins were found, the 0.025 fractile for iron in several age groups was even less than the concentration considered to indicate poor iron nutritional status.
Sensitivity of immunofixation electrophoresis for detecting IgM paraproteins in serum.
Authors: Kahn S N , Bina M 
Published: January 2020

Abstract
Detection and characterization of small IgM paraproteins by immunoelectrophoresis are often difficult because of (a) slow diffusion of the macromolecular immunoglobulin, and (b) the obscuring of the light chain, especially kappa, by the light chains of background polyclonal immunoglobulin (the "umbrella effect"). Various methods of sample pretreatment have been tried in an attempt to overcome this problem. Using immunofixation electrophoresis (IFE), we were able to detect and characterize IgM paraproteins in serum at concentrations as low as 0.25 g/L, even when the polyclonal immunoglobulin background was increased. With routine IFE, our laboratory identified 58 patients with IgM paraproteinemia in a four-year period. In 36, the paraproteins were present at less than 5 g/L; 10 of these were detectable only by IFE.
Production and characterization of genetically engineered antibody molecules.
Authors: Morrison S L , Canfield S , Porter S , Tan L K , Tao M H , Wims L A 
Published: January 2020

Abstract
Expression of antibody heavy- and light-chain genes by transfection permits the production of monoclonal antibodies with improved biological and antigen-binding properties. The immunoglobulin genes are placed in vectors containing a gene for encoding a protein that provides a biochemically selectable function in eukaryotic cells; these vectors are transfected into myeloma and hybridoma cells. Selection of drug-resistant cells permits the efficient isolation of the rare cells that express the transfected DNA. By placing heavy and light chains on plasmids with different selectable markers, one can deliver heavy- and light-chain genes simultaneously to the same cell. The transfected immunoglobulin genes are efficiently expressed and the proteins produced are a faithful mirror of the genes that were introduced. Using the standard techniques of genetic engineering and gene transfection, we can now produce antibodies of widely varying structures, including chimeric antibodies with segments derived from different species. These antibodies provide useful reagents to study structure-function relationships within the antibody molecule. Ultimately it will be possible to produce a new generation of antibody molecules with improved antigen-binding properties and effector functions.
Analysis of idiotypic and anti-idiotypic antibodies as models of receptor and ligand.
Authors: Linthicum D S , Bolger M B , Kussie P H , Albright G M , Linton T A , Combs S , Marchetti D 
Published: January 2020

Abstract
Antibodies to small bioactive ligands and peptides may mimic the binding characteristics of the natural receptor; in turn, the anti-idiotypic antibodies generated against the binding sites of such anti-ligand antibodies may mimic some aspects of small bioactive ligands and peptides. Among the several levels of investigation of such antibody-receptor networks are (a) the quantitative structure-activity relationships of ligand binding to antibody as compared with natural receptor; (b) the molecular modeling of antibody-receptor binding sites and the genomic basis for such structures; and (c) the characteristics of the molecular mimicry exhibited by "mimetopes" on anti-idiotypic antibodies. To illustrate the analysis encountered at each of these levels, we discuss here antibody and anti-idiotypic systems that are directed to small neuroactive ligands and their receptors.
High-performance immunoaffinity chromatographic detection of immunoregulatory anti-idiotypic antibodies in cancer patients receiving immunotherapy.
Authors: Phillips T M 
Published: January 2020

Abstract
Anti-idiotypic antibodies are regulatory antibodies responsible for the shutdown of active immune responses against growing tumor cells. In an attempt to study these antibodies, a technique for isolating specific anti-idiotypic antibodies by immunoaffinity chromatography was devised. Human anti-tumor antibodies were isolated by affinity absorption to fixed autologous tumor cells. These antibodies were biotinylated, immobilized on streptavidin-coated beads, and used as a ligand to isolate reactive anti-idiotypes from the plasma of patients during periods when immune reactivity against their tumors could not be detected. The isolated anti-idiotypes demonstrated the ability to react with the original antibodies and to inhibit their binding to autologous tumor cells. Thus functional anti-idiotypic antibodies can be isolated by immunoaffinity chromatography with the original idiotype as the ligand. This technique can be used to monitor regulatory antibodies in cancer patients receiving immunotherapy.
Inhibition of mannosidase in hybridomas yields monoclonal antibodies with greater capacity for carbohydrate labeling.
Authors: Simonson R B , Ultee M E , Long C G , Gillette R W , McKearn T J , Rodwell J D 
Published: January 2020

Abstract
Labeling an antibody site specifically through its carbohydrate residues preserves more of its antigen-binding activity than does labeling through protein moieties. To boost the amount of immunoglobulin G carbohydrate capable of being labeled, we treated hybridoma cells with a mannosidase inhibitor, deoxymannojirimycin (dMM). Polyacrylamide gel electrophoresis showed formation of a glycoprotein with high mannose content, in that endo-beta-N-acetylglucosaminidase H (EC 3.2.1.96) could digest the antibody from the dMM-treated cells, but not from control cultures. Carbohydrate analysis confirmed this conclusion, indicating that the antibody from the dMM-treated cells had twice as much mannose as did the control antibody. The glucosamine content of the treated-cells' antibodies was half that of the control, and no additional carbohydrate residues were detectable in the antibodies secreted by the dMM-treated cells. We conjugated both the dMM and control antibodies through their carbohydrate to a chelator. In labeling, the dMM antibody conjugate incorporated approximately threefold as much 111In isotope as the control conjugate. The two labeled antibodies were injected into mice and showed similar organ distributions.
Desirable performance characteristics and clinical utility of immunoglobulin and light-chain assays derived from data on biological variation.
Authors: Ford R P , Mitchell P E , Fraser C G 
Published: January 2020

Abstract
Using automated assays of IgG, IgA, and IgM, and kappa (kappa) and lambda (lambda) light-chains, we assessed the analytical, intra-individual, and interindividual components of variation in a cohort of 12 apparently healthy subjects to examine the utility of the Kallestad Immunochemical Evaluation system. The immunoglobulins and light-chains had small intra-individual variation, and, in consequence, good analytical precisions (CV) of 2.3%, 2.5%, 3.0%, 2.4%, and 2.4% are required for IgG, IgA, IgM, kappa, and lambda assays, respectively. All of these analytes, and the derived kappa/lambda and heavy-/light-chain ratios, have marked individuality. Conventional population-based reference values are of limited utility; therefore, the assays are unlikely to have high diagnostic sensitivity but will be very useful for monitoring individuals. The kappa/lambda ratio may be of particular value in monitoring because a change exceeding 4% does imply a significant (P less than or equal to 0.05) difference in serial results.
High sensitivity, homogeneous particle-based immunoassay for thyrotropin (Multipact).
Authors: Wilkins T A , Brouwers G , Mareschal J C , Cambiaso C L 
Published: January 2020

Abstract
We describe the first homogeneous, nonradioactive, high-sensitivity assay for human thyrotropin (TSH). The assay is based on particle immunoassay techniques, wherein 800-nm particles form the basis for the immunochemistry, delivery, and the detection technologies, respectively. Our assay also is the first to involve the use of fragmented monoclonal antibodies (to eliminate serum interferences) covalently coupled to particles without loss of their binding properties. Assays are performed in a semiautomated mode with use of a new modular system (Multipact). Equilibrium is reached in less than 2 h. Precision profile, sensitivity, and clinical studies indicate that the assay is accurate, has good precision at low concentrations, and that detection-limit characteristics compare well with those of a leading commercial high-sensitivity immunoradiometric assay (IRMA) for TSH. Dilution characteristics were satisfactory down to the assay's detection limit for a range of clinical samples. Correlation studies vs a reference IRMA method yielded the regression equation, present method = 0.976 (IRMA) + 0.002 milli-int. unit/L (r = 0.98), for 223 samples with TSH concentrations in the range 0 to 30 milli-int. units/L. For 40 samples with TSH less than or equal to 1.0 milli-int. unit/L it was: present method = 0.94 (IRMA) + 0.005 milli-int. unit/L (r = 0.96).
Immunoblotting with (sub)class-specific antibodies reveals a high frequency of monoclonal gammopathies in persons thought to be immunodeficient.
Authors: Radl J , Wels J , Hoogeveen C M 
Published: January 2020

Abstract
Immunoblotting, in combination with high-resolution electrophoresis and the use of mouse monoclonal antibodies to human (sub)class immunoglobulin (Ig) isotypes, substantially increased the sensitivity with which homogeneous Ig components (H-Ig) could be detected. Using this technique, we reinvestigated 40 selected sera, previously found to be negative for H-Ig by agar electrophoresis and immunofixation, from two groups of individuals thought to have an age-related immunodeficiency, i.e., persons older than 95 years and recipients of kidney grafts who were undergoing immunosuppressive treatment. In both groups, small single or multiple H-Ig components were found, in frequencies of 76% and 79%, respectively. For comparison, the Ig spectrum of 10 sera from patients on dialysis treatment and of 33 sera from young adult blood donors was ordinarily heterogeneous, except for one elderly patient and one blood donor with a previously unknown IgG2 deficiency. These results are complementary to the observations in some immunodeficiencies in children and indicate that the appearance of single or multiple H-Ig components in low concentration can be considered a very sensitive indicator of certain immune system disorders forming a separate category of monoclonal gammopathies.
Skin-puncture and blood-collecting technique for infants: update and problems.
Authors: Meites S 
Published: January 2020

Abstract
This is updated information on acceptable practice in skin puncture and blood collection in infants, as well as on the devices used, with the additional aim of emphasizing major problem areas and some tentative solutions. Consensus standards for skin puncture have little experimental support, and evade the hard fact that studies are needed to clarify optimum sites for puncture and depth and width of lancets, and to assess the effects of compression and skin resistance in the puncturing process. Preliminary data revealed that the puncturing depth of 2.4 mm recommended for the newborn is excessive. In four of 14 newborns at necropsy, the distance from posterior planar skin surface to underlying bone ranged between 2.0 and 2.2 mm. An experimental lancet, with a 1.8-mm tip length and a diameter of 0.79 mm yielded customary blood volumes from newborns in three of the four pediatric centers where it was tested. Lack of success with the lancet was attributed to inexperienced phlebotomists, not to the lancet's decreased size. Also reviewed are problems with common devices used, and the need for examining the "economy" of blood collection.
A multi-factor experimental design for evaluating random-access analyzers.
Authors: Krouwer J S , Stewart W N , Schlain B 
Published: January 2020

Abstract
A multi-factor experimental design for evaluating random-access analyzers has been developed and tested for the Ciba Corning "550 Express" random-access analyzer. The 12-sample design estimates imprecision, slope, nonlinearity, linear drift, and reagent carryover to the next assay. The design was constructed so that estimates of the factors' effects are almost entirely uninfluenced by each other. Use of the design is illustrated by an example in which reagent-to-assay carryover was pinpointed as an apparent cause of high imprecision. This led to a modification of the analyzer such that carryover was insignificant. The appendix contains a 27-sample design that provides additional estimates. Software to perform such calculations is available on request.
Laboratory evaluation of the Du Pont "Dimension Clinical Chemistry System".
Authors: Knight D , Singer R , White J M , Fraser C G 
Published: January 2020

Abstract
We evaluated the analytical performance of the Du Pont Dimension Clinical Chemistry System to assess its suitability as a replacement for the Du Pont aca III, currently routinely used for analysis of pediatric, high-risk, and emergency specimens. Twenty-six analyses were studied. These generally fulfilled pre-set analytical goals for precision based on biological variation or "state of the art." Significant economies were achieved and we found the Dimension to be reliable, easy to operate, and simple to maintain. It also fulfilled safety requirements for analysis of specimens of high risk to laboratory staff.
Evaluation of a radioimmunoassay of urinary cortisol without extraction.
Authors: Huang C M , Zweig M 
Published: January 2020

Abstract
We evaluated the Kallestad "Quanticoat" cortisol RIA for direct (no extraction) measurement of urinary free cortisol, which requires no solvent extraction. An analytical-recovery study showed a linear regression of y (measured) = 0.65x (added) + 37.5 micrograms/L (Sy.x = 21.4 micrograms/L, r = 0.978, n = 48). Recovery appeared to vary with the urine used and with the concentrations of cortisol added. Within- and between-run CVs were less than or equal to 4.1% and less than or equal to 3.8%, respectively. Cross reactivities were low, except for prednisolone (20.5%). This no-extraction method gave higher values for urinary free cortisol than did either an RIA method involving extraction or an HPLC method. A comparison study with the HPLC (x) and with the method involving extraction (x') gave the following Deming-debiased regression equations: y = 1.60x + 68.8 (Sy.x = 34.4, n = 29) and y = 1.33x' + 0.69 (Sy.x = 40.3, n = 66), respectively. We conclude that the no-extraction method may give misleading results for patients' diagnosis or management if this cross reactivity is not taken into account.
Coloscreen VPI test kit evaluated for detection of fecal occult blood.
Authors: Scriven A J , Tapley E M 
Published: January 2020

Abstract
The usefulness of the Coloscreen VPI test kit in occult blood detection has been examined and compared with our current method. The results show the Coloscreen procedure to be a simple, sensitive method that is much less subject to vegetable peroxidase interference than are other available screening procedures.
A rapid sample-preparation technique for thin-layer chromatographic analysis for 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid in human urine.
Authors: King D L , Gabor M J , Martel P A , O'Donnell C M 
Published: January 2020

Abstract
In this rapid TLC method of analysis for the urinary cannabinoid metabolite, 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), hydrolyzed urine specimens are aspirated through a porous, alkyl-silica extraction layer located along the lower edge of a biphasic thin-layer chromatogram; THC-COOH is simultaneously extracted from the sample and concentrated on the TLC plate for subsequent migration and detection. The method, evaluated in a blind study, identified all samples containing THC-COOH greater than or equal to 20 micrograms/L. The technique increases samples throughput, sensitivity, and specificity as compared with conventional TLC methods and is applicable to a wide variety of compounds.
Effects of estrogen on mineral metabolism in postmenopausal women as evaluated by multiple assays measuring parathyrin bioactivity.
Authors: Stock J L , Coderre J A , Posillico J T 
Published: January 2020

Abstract
Data on the effect of estrogen on immunoreactive parathyrin (iPTH) in postmenopausal women are conflicting. We administered estrogen or placebo to 21 postmenopausal women for 12 weeks and measured PTH bioactivity (bioPTH), using the renal cytochemical bioassay. Before treatment, there was a negative correlation between nephrogenous cAMP and the tubular maximum for urinary phosphate excretion and a positive correlation between values measured by a mid-region-specific PTH RIA and those measured in an immunoradiometric assay for intact PTH. Values measured by the midregion-specific RIA were also positively correlated with nephrogenous cAMP. BioPTH values were not correlated with other indices of PTH activity but were increased compared with values for younger subjects. After estrogen treatment there was no change in bioPTH activity despite an early decrease in serum osteocalcin and a later increase in nephrogenous cAMP. PTH concentrations measured by mid-region-specific or intact RIAs were unchanged, but sample size may have been insufficient to exclude the possibility of significant changes in these values. The effects of estrogen on mineral metabolism in postmenopausal women are time-dependent. Early effects are independent of PTH, and later effects are variably associated with increased PTH activity.
Liquid-chromatographic determination of acetylated hemoglobin.
Authors: Turpeinen U , Stenman U H , Roine R 
Published: January 2020

Abstract
In this liquid-chromatographic assay for acetylated hemoglobin in human blood, glycated hemoglobins in hemolysates are first removed by affinity chromatography on boronate-agarose columns. Acetylated hemoglobin in the nonretained fraction is determined by cation-exchange chromatography. The absorbance of the effluent is monitored at 415 nm. The mean within-assay CV was 8.5%, the between-assay CV 17%. The mean proportion of acetylated hemoglobin in 20 pregnant, nondiabetic women was 1.9%, and in 17 alcoholics it was 2.7%. Rapid and reproducible, this method is suitable for use in routine determination of acetylated hemoglobin.
An improved radioimmunoassay of C-peptide and its application in a multiyear study.
Authors: Myrick J E , Gunter E W , Maggio V L , Miller D T , Hannon W H 
Published: January 2020

Abstract
A commercial radioimmunoassay (RIA) for human proinsulin C-peptide was modified to improve its ruggedness and specificity, to decrease the influence of specimen matrix, and to shorten "hands-on" time. In the new protocol, we prepare calibrators in a C-peptide-free serum pool, prepared by treatment with activated charcoal (biological matrix), instead of in a defined matrix. This yielded essentially 100% analytical recoveries for C-peptide concentrations up to 300 pmol/L, a broader analytical range. We also corrected calibrators and unknown samples for nonspecific binding (NSB). Decreasing the concentration of ethanol (from 950 to 880 mL/L) for differential precipitation of the antigen-antibody complex resulted in an NSB of less than 10%, while maintaining high bound/total count percentages for samples and calibrators. C-peptide is thermally unstable without aprotinin at -20 degrees C and with or without aprotinin at 4 degrees C or above, but multiple freeze-thaw cycles do not affect C-peptide in serum. The modified C-peptide assay was applied to plasma from a multiyear study (fasting and post-carbohydrate-challenge subjects). During the four years of the study CVs ranged from 1.9% to 8.6% for replicate analyses of C-peptide in samples with concentrations less than or equal to 500 pmol/L. Between-run CVs were 3.8% to 8.2%, total CVs 3.8% to 10.7%.