bluuebunny/crossref_metadata_2025_split huggingface dataset:
ImmunoConcentration--a new format for solid-phase immunoassays.
Authors: Valkirs G E , Barton R 
Published: January 2020

Abstract
A new format for solid-phase immunoassays has been developed in which a monoclonal antibody-coated membrane, incorporated into a cylindrical, disposable device, regulates sample and reagent delivery. We illustrate the method with a two-site, immunoenzymometric assay that can detect human choriogonadotropin at less than 50 int. units/L (4 micrograms/L) in urine and less than 25 int. units/L (2 micrograms/L) in serum and takes less than 5 min to perform. The solid-phase antibody is located in a circular area in the center of the membrane so that in the presence of the hormone, after addition of substrate, a blue enzyme product is generated in this circular area. The high ratio of surface area to volume within the microporous matrix of the membrane assures short diffusion distances and therefore rapid binding of liquid-phase reagents to the solid phase. Pseudo-first-order reaction kinetics describe the binding of antigen to immobilized antibody and the binding of enzyme-labeled antibody to immobilized antigen. The speed and simplicity of this format may facilitate testing for many analytes, both soluble and particulate, as well as serological testing.
Fc receptors for IgG on human neutrophils: analysis of structure and function by using monoclonal antibody probes.
Authors: Rosenberg J S , Melnicoff M J , Wilding P 
Published: January 2020

Abstract
Structural and functional characteristics of Fc receptors for IgG (Fc gamma) on human neutrophils were examined with two monoclonal antibody probes specific for the Fc gamma receptors, Leu 11b and 3G8. To determine the distribution, density, and membrane mobility of the Fc gamma receptor, we used immunogold staining techniques, flow cytometry analysis, and fluorescence microscopy. Both 3G8 and Leu 11b inhibited several cell functions, thereby depicting the regulatory role of the Fc gamma receptor in mediating neutrophil activities. Among the functions studied were release of lysosomal enzymes, release of superoxide anion (O2-), and Fc-dependent rosette formation and phagocytosis. The densities of Fc gamma determinants recognized by Leu 11b and 3G8 on cells from a patient with chronic myelogenous leukemia were less than the density of epitopes on neutrophils from a normal individual. Taken together, the detailed analysis of physical and functional aspects of the Fc gamma receptor on neutrophils described in this study serve as a model for further assessment of the use of Fc gamma phenotyping of cells as a diagnostic tool.
Capsule chemistry technology for high-speed clinical chemistry analyses.
Authors: Cassaday M , Diebler H , Herron R , Pelavin M , Svenjak D , Vlastelica D 
Published: January 2020

Abstract
We describe a new analytical approach--"capsule chemistry"--for high-speed, selective analysis of a wide variety of analytes. Sequential micro-aliquots of sample and reagents are encapsulated within an inert fluorocarbon liquid. The resulting "test capsule" is introduced into a single analytical flow path, composed of a solid fluorocarbon, Teflon, where the sample is incubated, mixed, reacted, and measured as a moving series of individual tests. These randomly selective assays are processed at a rate of 720 per hour. The unique physical interaction between the liquid and solid fluorocarbon carrier materials effectively prevents detectable "carryover" of aqueous constituents between the successive test capsules. Reactions are monitored through the walls of the Teflon analytical channel at nine in-line detector stations for colorimetric and nephelometric measurements.
Two-dimensional centrifugation for desk-top clinical chemistry.
Authors: Schultz S G , Holen J T , Donohue J P , Francoeur T A 
Published: January 2020

Abstract
We have developed a new system for clinical chemistry analysis, the Vision System, in which centrifugal force is used to separate whole blood, measure reagent and plasma volumes, and complete all steps required for a spectrophotometric analysis. The system is based on use of a multichambered plastic test pack containing liquid reagents, which can be centrifuged at 500 X g in two planes, oriented at right angles to each other. Alternating centrifugal fields allows liquid reagents and plasma to flow into highly precise measuring and mixing chambers. A unique flash lamp and diode array spectrometer provide for optical measurements of 10 test packs at as many as eight wavelengths simultaneously. The temperature of each individual test pack is controlled by using a flash lamp coupled to a liquid crystal temperature sensor. Microprocessor control allows as many as 10 different chemistry reactions to be measured simultaneously on whole-blood, plasma, or serum samples. Comparison with results by an established batch-photometric analyzer demonstrated excellent precision and accuracy for various clinical chemistry tests.
A nephelometry system for the Abbott TDx analyzer.
Authors: DeGrella R F , Combs G L , Coffee E E , Stern C H , Frenkel D , Kureshy F , Kanewske W J , Hiatt D A , Shanks R E , Pumphrey J G 
Published: January 2020

Abstract
A self-contained light-scattering accessory carousel has been developed for the Abbott TDx fluorescence polarization analyzer, extending the instrument's capabilities to nephelometric methods of analysis, including assays for specific proteins by immunoprecipitation: IgG, IgA, IgM, and transferrin. The scattered light from a green-light-emitting diode (peak wavelength 565 nm) is measured at an angle of 37.5 degrees by the existing optical detection system of the TDx analyzer without modification of the instrument. Measurements are made at quasi-equilibrium, with sample blank correction. No sample pretreatment is required, and antigen-excess is checked automatically. CVs range from 3 to 6% (within-run) and 7 to 9%. (total). Calibration curves may be stored for at least two weeks. A nephelometric method for monitoring chromogenic reactions in the green wavelength region is also described. This method--Scattered Energy Attenuation (SEA)--has been used in preliminary experiments to measure calcium, total protein, iron, and bilirubin.
Two-dimensional gel electrophoresis of cerebrospinal fluid proteins from patients with various neurological diseases.
Authors: Wiederkehr F , Ogilvie A , Vonderschmitt D J 
Published: January 2020

Abstract
We subjected cerebrospinal fluid (CSF) samples from over 200 patients with various neurological diseases to two-dimensional electrophoresis. The series included non-inflammatory diseases such as epilepsy, amyotrophic lateral sclerosis, and polyneuropathy; and inflammatory diseases such as multiple sclerosis and neurolues. In the resulting electrophoretograms we considered mainly the region of CSF-specific proteins and the area corresponding to the immunoglobulin light chains. The former, at Mr 35 000-38 000, shows some interesting variations from one CSF to another. Samples from patients with various brain tumors show a specific change. A zone of oligoclonal immunoglobulin light chains appeared in all CSF samples with above-normal gamma-globulin content. These oligoclonal patterns remained constant and characteristic during the course of different diseases for several patients so examined. As expected, differences appeared in the patterns of immunoglobulin light chains from one individual to another, even among a group of patients with the same disease. The extent of the correlation of certain basic patterns with certain diseases cannot yet be determined.
Use of chromatofocusing to detect a transferrin variant in serum of alcoholic subjects.
Authors: Storey E L , Mack U , Powell L W , Halliday J W 
Published: January 2020

Abstract
We describe a technique for detecting an abnormal (pl 5.7) transferrin component in serum, which appears after prolonged heavy consumption of alcohol. Serum transferrin was purified by chromatography on DEAE-Affi-Gel Blue and analyzed by chromatofocusing on an ion-exchange column (Mono P). The abnormal transferrin component was detected in 17 of 20 patients (85%) with a history or prolonged consumption of alcohol (100 g per day), and in control subjects who ingested up to 80 g of alcohol per day for seven days, but not in 14 normal control subjects or 14 patients with liver disease unrelated to alcohol. The variant consistently disappeared from the serum within three weeks of cessation of alcohol consumption. It is apparently produced by desialylation of ordinary human transferrin. We find that chromatofocusing on an ion-exchange column is a sensitive and reliable technique for its identification and conclude that detection of this desialylated transferrin indicates recent prolonged alcohol ingestion.
Inaccurate values for direct bilirubin with some commonly used direct bilirubin procedures.
Authors: Chan K M , Scott M G , Wu T W , Clouse R E , Calvin D R , Koenig J , Lichti D A , Ladenson J H 
Published: January 2020

Abstract
We compared five methods for the determination of total and direct bilirubins in serum samples from normal controls, subjects with Gilbert's syndrome, and serum pools containing about 50 and 150 mg of total bilirubin per liter. The Kodak Ektachem method and a diazotized sulfanilic acid method with 0.15 mmol/L sodium nitrite concentrations are the only methods that gave accurate direct bilirubin values, as judged by liquid-chromatographic results. The aca method that involved p-nitrobenzene diazonium tetrafluoroborate and another diazotized sulfanilic acid method with a higher concentration of sodium nitrite (0.8 mmol/L) yielded falsely high values for direct bilirubin, which could lead to clinical confusion. The more recently introduced diazotized sulfanilic acid method of the aca gave substantially better results than the p-nitrobenzene diazonium tetrafluoroborate method but was still inaccurate. Systematic investigation of these procedures revealed that the overestimation of direct bilirubin by the diazotized sulfanilic acid method was related to the amount of unconjugated bilirubin present and its ability to react as direct bilirubin in the presence of higher concentrations of sodium nitrite. Inherent properties of p-nitrobenzene diazonium tetrafluoroborate appeared to be responsible for inaccuracies in that method, which could not be corrected by varying reagent concentration or the reaction conditions.
Turbidimetry of rheumatoid factor in serum with a centrifugal analyzer.
Authors: Borque L , Yago M , Mar C , Rodriguez C 
Published: January 2020

Abstract
We describe the simple, rapid turbidimetry of IgM rheumatoid factor in human serum by use of the Cobas-Bio centrifugal analyzer. Heat-aggregated human IgG is used as the antigen. The immunoturbidimetric reaction is monitored at 340 nm for 300 s, and the changes in absorbance after the antigen is added are used to prepare the standard curve. Test results are calculated from the stored curve and reported in int. units/mL, based on comparison with the WHO reference serum for rheumatoid factor. There is no interference from bilirubin (up to 340 mumol/L) or hemoglobin (up to 5600 mg/L). Serum samples with a triglyceride concentration greater than 2.20 mmol/L must be cleared of lipids before analysis. The standard curve is linear from 30 to 500 int. units/mL. Precision, accuracy, linearity, and sensitivity are quite acceptable. The CV was generally less than 5% for different concentrations of rheumatoid factor. Results agree well with those by a rate-nephelometric procedure on the Beckman ICS system (rs = 0.932). However, both correlate poorly with a modified classical Waaler-Rose test. Of 47 patients with rheumatoid arthritis, 34 had IgM rheumatoid factor in their serum, but the measured value did not reflect the activity of the disease.
Electrophoretic characteristics of macro creatine kinase type 2 in serum.
Authors: Rogalsky V Y , Koven I H , Miller D R , Pollard A 
Published: January 2020

Abstract
We have studied the electrophoretic characteristics of a creatine kinase (CK, EC 2.7.3.2) isoenzyme, macro creatine kinase type 2 (MCK-2), in the serum of 42 patients with carcinoma of the colon. The patients could be divided into three subgroups by the intensity of the MCK-2 band (nine high, nine medium, and 24 low intensity), but we detected no correlation between the isoenzyme activity and the stage of the cancer. Inhibition of the activity of the CK-M subunit by antibody to CK-M allowed more sensitive detection of MCK-2 in serum and revealed that MCK-2 may be obscured by CK-MM. Moreover, there may be major discrepancies between the amount of MCK-2 seen on electrophoresis and the apparent total CK.
Ion-selective membrane electrode for rapid automated determinations of total carbon dioxide.
Authors: Scott W J , Chapoteau E , Kumar A 
Published: January 2020

Abstract
Previously described ion-selective membrane electrodes useful for determination of total carbon dioxide in biological fluids in automated analyzers show interference from several sources--e.g., fatty acids, keto acids, salicylate, heparin. Judicious selection of membrane components has produced a membrane with superior performance characteristics: short conditioning time, long lifetime in storage, rapid and stable response, low drift, and significantly less susceptibility to interference than other electrodes thus far reported. Samples can be analyzed at 240 samples or more per hour and results correlate well with those by, e.g., the Technicon SMAC II method for total carbon dioxide. Mounted on the Technicon RA-1000, the carbon dioxide sensor is arranged in tandem with sodium and potassium ion-selective electrodes. When all three species are measured in the same buffered sample stream, the sampling rate thus becomes 720 tests per hour, done on 25-microL samples.
Specific 125I radioimmunoassay for morphine.
Authors: Edwards D J , Popovski Z , Baumann T J , Bivins B A 
Published: January 2020

Abstract
In this specific radioimmunoassay procedure for morphine, samples are first subjected to an extraction procedure to remove the major metabolite of morphine (morphine-3-glucuronide), then quantified by use of a commercial radioimmunoassay kit with 125I-labeled morphine. Concentrations between 10 and and 100 micrograms/L are routinely measured with a within-run CV of less than 2.0% and a between-run CV of 3.5%. This rapid, specific, and sensitive method requires minimal technical skills and analytical equipment that is common to most laboratories.
Plasma L-dopa in the diagnosis of malignant melanoma.
Authors: Faraj B A , Camp V M , Murray D R , Kutner M , Hearn J , Nixon D 
Published: January 2020

Abstract
We determined the concentration of L-dopa in the plasma of 98 patients with biopsy-proven melanoma, a dermatological neoplasm that is characterized biochemically by abnormal tyrosine metabolism. For 21 patients previously diagnosed as having melanoma but who were clinically free of disease (stage I), the mean concentration of L-dopa in plasma, 1.01 (SD 0.12) micrograms/L, was not significantly different from that of 32 normal controls, 1.23 (SD 0.16) micrograms/L. However, L-dopa was increased significantly (p less than 0.001) in the plasma of all of 65 patients with active disease (stage II), 2.08 (SD 0.46) micrograms/L, and was highest in 12 patients with stage III malignant melanoma, 8.40 (SD 3.50) micrograms/L. The development of metastases in four patients with stage II melanoma was accompanied by an increase in the concentration of plasma L-dopa. These studies suggest that measurement of plasma L-dopa may be useful in the diagnosis of melanoma.
Components of variance analysis of data produced in a national quality-control survey of radioimmunoassays of thyroxin, triiodothyronine, thyrotropin, prolactin, and progesterone.
Authors: Pilo A , Zucchelli G C , Chiesa M R , Bolelli G F , Albertini A 
Published: January 2020

Abstract
Data collected in a collaborative survey for radioimmunoassays have been studied by using analysis of variance to estimate the within-kit (CVw.kit) and the between-kit (CVb.kit) components of the total variability (CVT). This analysis has been applied to the results for triiodothyronine, thyroxin, thyrotropin, prolactin, and progesterone produced by 80-150 laboratories that assayed blind, replicate samples. Total variability was lowest in the thyroxin assay (CVT = 10.9%), associated with a very close between-kit agreement (CVb.kit = 4.0%); in the triiodothyronine assay, on the other hand, the large between-kit component (CVb.kit = 10.1%) increased the total variability to 16.1%. In the prolactin assay the CVT of 19.3% included 17.5% CVw.kit and 8.1% CVb.kit. Assays for thyrotropin and progesterone involve analyses of two pools at different hormone concentrations. The CVb.kit component was very high in the low-concentration pool, both for thyrotropin (25.1%) and progesterone (45.2%); in the higher-concentration pool it decreased to 8.3% for thyrotropin but remained high (21.6%) for progesterone. Applying analysis of variance to the triiodothyronine and thyroxin data obtained by different laboratories using the same kit showed that most kits yielded significantly different measurements when used in different laboratories.
Determination of retinyl esters and retinol in serum or plasma by normal-phase liquid chromatography: method and applications.
Authors: Bankson D D , Russell R M , Sadowski J A 
Published: January 2020

Abstract
Retinol and retinyl esters are measured in serum or plasma samples by gradient, normal-phase, adsorption "high-performance" liquid chromatography, with ultraviolet detection at 325 nm. The four major circulating retinyl esters in humans (esters of palmitate, stearate, oleate, and linoleate) are coeluted as a single peak. Retinyl acetate is included as an internal standard, to correct for variable recovery. Retinol values so measured correlated well (r = 0.88) with those by a widely used reversed-phase chromatographic technique (Clin Chem 1983;29:708-12). The mean retinol concentration was 570 (SEM 17) micrograms/L and the mean for retinyl esters was 33 (SEM 4) micrograms/L as determined in samples from 88 fasting young adults. Concentrations of retinol in plasma as low as 50 micrograms/L can be detected in 100-microL samples, as can 10 micrograms of retinyl esters per liter. Using this method, we measured absorption of low doses of vitamin A, which may provide a more physiological approach to assessment of fat malabsorption. Additionally, the procedure proved useful for quickly screening for vitamin A toxicity. Major advantages include small sample size, direct injection of the extract ed sample without evaporation, rapid elution pattern, co-elution of major retinyl esters as a single peak, and low limit of detection.
Plasma lipase properties as related to pancreatic condition.
Authors: Arzoglou P L , Lessinger J M , Férard G 
Published: January 2020

Abstract
We examined the sensitivity to colipase of two types of lipase (EC 3.1.1.3) activity in plasma. Results were very similar for plasma lipase corresponding to that found in cases of acute pancreatitis and for swine pancreas lipase, whereas we found some differences between "pancreatitis lipase" and lipase from healthy subjects. Gel-filtration experiments suggest that the two forms of lipase in plasma have different relative molecular masses; moreover, their avidity for antibodies against human pancreatic lipase differs. Guided by these studies, we propose optimal conditions for nephelometry of "pancreatitis" lipase.
Direct homogeneous phosphoroimmunoassay for carbamazepine in serum.
Authors: Sidki A M , Smith D S , Landon J 
Published: January 2020

Abstract
In this "phosphoroimmunoassay," a phosphorescent label is used: erythrosin (tetraiodofluorescein). Its long-lived phosphorescence was detected after pulsed excitation in a time-resolved luminescence spectrometer. To achieve convenient open-atmosphere phosphorimetry in liquid solution at room temperature, we used sodium sulfite as an "in situ" chemical deoxygenator, to eliminate oxygen quenching of the excited triplet state. Time-resolved detection allows for complete rejection of short-lived background signals, including those from fluorescent or light-scattering components of biological fluids that can interfere in fluoroimmunoassays. We chose the antiepileptic drug carbamazepine (CBZ) and its active metabolite CBZ-10, 11-epoxide (CBZE) to demonstrate the development and validation of nonseparation assays based on quenching the phosphorescence of erythrosin-labeled drug upon binding to antibody. These two compounds cross reacted equally with the antiserum used; hence, we measured the activity of both in patients' sera. Alternatively, simple pre-treatment of the sample with acid destroys CBZE immunoreactivity and enables specific assay of CBZ.
Direct enzymic measurement of glycerides in serum and in lipoprotein fractions.
Authors: Kohlmeier M 
Published: January 2020

Abstract
A simple two-step procedure is now available for directly measuring triglycerides in whole serum and in lipoprotein fractions. I tested the performance of the assay, using pooled serum stored frozen, freshly prepared lipoprotein fractions, and pure glyceride standards. A parabolic concentration-response curve ensured linearity well beyond total glycerol concentrations of 10 mmol/L, but gave rise to misleading results for massively lipemic samples. Within-day CVs averaged 2.2% for the stored-frozen serum pools; mean day-to-day variation was 2.4%. Analytical recoveries of triglycerides, after lipoprotein fractionation, ranged between 101.9 and 103.7%. Aqueous glyceride standards gave results equivalent to between 95 and 105% of their glycerol content.
Determination of histamine concentrations in plasma by liquid chromatography/electrochemistry.
Authors: Harsing L G , Nagashima H , Duncalf D , Vizi E S , Goldiner P L 
Published: January 2020

Abstract
Histamine was extracted from deproteinized plasma with Amberlite CG 50 weak cation-exchange resin (analytical recovery of [3H]histamine, 60.5%). The eluate was evaporated and histamine in the redissolved sample was condensed with o-phthalaldehyde and 2-mercaptoethanol at pH 11.5. This adduct was separated by liquid chromatography under isocratic conditions and oxidized on a glassy carbon electrode at +0.4 V for electrochemical detection. 3-Methylhistamine was used as internal standard. As little as 0.45 pmol of standard histamine condensate was detected. The histamine concentration in 88 human plasma samples appeared to be normally distributed; its mean value was 7.20 (SD 2.61) nmol/L. Authentic and extracted histamine produced similar hydrodynamic voltammograms, and exogenous and endogenous histamine gave identical chromatographic characteristics with different mobile phases or different chromatographic columns. Standard and extracted histamine had similar degradation rates when samples were incubated with diamine oxidase (EC 1.4.3.6). Analytical recovery of known amounts of histamine added to pooled plasma was 97.7% (SD 22.3%). The inter- and intra-assay CVs for histamine determinations were 9.0% and 8.6%, respectively.