bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of human apolipoprotein E3, E2, and E4 genotypes by an allele-specific oligonucleotide-primed polymerase chain reaction assay: development and validation
Authors: Green E K , Bain S C , Day P J , Barnett A H , Charleson F , Jones A F , Walker M R 
Published: January 2020

Abstract
A polymerase chain reaction (PCR) assay has been developed and validated by using allele-specific oligonucleotide (ASO) primers to specifically amplify E3, E2, and E4 polymorphic sequences of the human apolipoprotein E (apo E) genes. Degenerate ASOs containing one or two additional 3' mismatches provided greater specificity than did ASOs containing a single mid-sequence or 3' allele-specific mismatch with plasmid pEB4 or genomic DNA as template. Optimal specificity and efficiency of amplification did not correlate with primer annealing conditions, whether determined theoretically or via oligo-melting experiments. Pre-cycling denaturation times and high cycling denaturation temperatures were also required for optimal amplification, presumably because of the high G:C content (75-85%) of apo E gene sequences. Conditions permissive for amplification and discrimination with plasmid DNA did not transpose favorably to amplification from human genomic DNA from peripheral blood leukocytes; the latter required nested primer reactions. These data may be valuable in predicting PCR assay conditions for other G:C-rich sequences containing polymorphic sequence differences. The assay described is both more accurate and rapid (24 h) than previously described methods for phenotyping or genotyping human apo E from blood specimens.
Improved fluorometric determination of malonaldehyde
Authors: Conti M , Morand P C , Levillain P , Lemonnier A 
Published: January 2020

Abstract
Lipoperoxidation is implicated in various pathological conditions. Malonaldehyde (MDA) is the most commonly used marker of this process. We propose simple modifications to Yagi's fluorometric assay for MDA determinations, to avoid long and tedious manipulations by eliminating the first precipitation and washing steps, analogous to HPLC methods, and to increase both the sensitivity and the specificity of the assay by measuring synchronous fluorescence. The proposed technique is easier, faster, and more sensitive than Yagi's method (Academic Press, 1982: Lipid peroxides in biology and medicine). The results obtained with the novel method correlate with those from the HPLC method described by Therasse and Lemonnier (J Chromatogr Biomed Appl 1987;413:237-41).
Drug analysis at the 1988 Olympic Winter Games in Calgary
Authors: Chan S C , Torok-Both G A , Billay D M , Przybylski P S , Gradeen C Y , Pap K M , Petruzelka J 
Published: January 2020

Abstract
A comprehensive drug testing program was carried out during the 16 days of the 1988 Olympic Winter Games in Calgary, Canada. State-of-the-art technology was applied, involving high-resolution gas chromatography, high-performance liquid chromatography, gas chromatography/mass spectrometry, fluorescence polarization immunoassay, and radioimmunoassay. Samples from selected athletes were screened for five drug classes: stimulants, narcotic analgesics, anabolic steroids, beta-blockers, and diuretics. In addition, samples were also screened for local anesthetics, corticosteroids, beta-human choriogonadotropin, and cannabinoids. During the 16-day event, 428 urine samples were processed and 3090 screening procedures performed. We describe the methods for analysis at the Olympic Games and present the results.
Characterization of sodium-selective optode membranes based on neutral ionophores and assay of sodium in plasma
Authors: Seiler K , Wang K , Bakker E , Morf W E , Rusterholz B , Spichiger U E , Simon W 
Published: January 2020

Abstract
Plasticized poly(vinyl chloride) membranes that incorporate a highly lipophilic sodium-selective neutral ionophore (ETH 4120) and novel H(+)-selective chromo-ionophores, lipophilic isologs of Nile Blue, are used in the competitive binding of Na+ and H+ for a reversible, optical determination of sodium activities in buffered solutions at different selected pH values. These optode membranes are used to assay total sodium concentrations in pH-buffered human blood plasma.
Carboxyterminal propeptide of type I procollagen in cerebrospinal fluid in childhood and in children with leukemia undergoing intrathecal treatment
Authors: Vainionpää L , Risteli L , Lanning M , Risteli J 
Published: January 2020

Abstract
We determined the reference interval for the carboxyterminal propeptide of type I procollagen (PICP), an indicator of the synthesis of type I collagen, in cerebrospinal fluid (CSF) by studying 32 infants and children, ages less than or equal to 15 years. The concentration of PICP is age dependent, with particularly high concentrations occurring in children younger than 1.5 years. In older children the concentration is stable (reference interval 20-92 micrograms/L). We also investigated the possibility that PICP in CSF could reflect local fibroproliferative changes in the arachnoid in a cohort of 42 children with acute lymphoblastic leukemia who were monitored by repeated sampling in connection with intrathecal therapy. Initially, there was no difference in PICP between the children with newly diagnosed leukemia and the controls. PICP concentrations were significantly higher (P less than 0.01) during intrathecal methotrexate therapy, with median values above the reference interval. Continuous corticosteroid treatment was associated with a significant decrease in PICP (P less than 0.02 and P less than 0.01, respectively, in two groups treated according to different protocols), close to the lower limit of the reference interval. Intrathecally administered methotrexate and systemic corticosteroid treatment are known to be associated with the development of arachnoiditis and with general repression of collagen synthesis, respectively. We conclude that PICP in CSF is a sensitive indicator of local fibroproliferation and ongoing collagen synthesis.
Analysis of ion behavior and potentials in a Na+ ion-selective membrane containing methyl monensin
Authors: Fujiwara M 
Published: January 2020

Abstract
Ion-selective electrodes (ISEs) are widely used in clinical examinations. The mechanisms of ISEs have been studied to develop a disposable ISE for "dry chemistry" analyses. The behavior of Na+ and Ag+ in an ion-selective polymer liquid membrane (ISM) containing methyl monensin (MMO), which is selective for Na+, has been clarified by x-ray microanalysis and measurement of electrical potential. The results indicate that Na+ is not transported across the membrane because of a stability of the Na(+)-MMO complex, whereas Ag+ (from the Ag/AgCl electrode) is transported with Cl- across the membrane by diffusion. The difference in potential, which follows a Nernst gradient, is generated by the formation of a double layer of electrons at the interface between the ISM and the electrolyte solution. These results are explainable by the stability of the trap in the polymer liquid membrane. MMO acts as a stable trap of Na+ and as a metastable site of Ag+ for movement.
Micro method of analysis for magnesium in myocardial biopsies
Authors: Millane T , Devarajan S , Fashola T , Bush R , Holt D W 
Published: January 2020

Abstract
We developed a single-stage technique involving a proteolytic enzyme (pepsin) for the solubilization of cardiac muscle to measure magnesium in tissue. This new method has been developed specifically for use with very small cardiac biopsy samples (less than 1 mg) obtained with modern myocardial biopsy forceps. Pepsin digestion of the tissue releases magnesium ions into solution and, after centrifugation and dilution with lanthanum chloride, the resulting supernate is suitable for analysis by atomic absorption spectrometry. Recovery of magnesium after a single digestion approaches 99%. In direct comparison studies of pepsin digestion and a traditional method involving nitric acid extraction, the pepsin digestion consistently yielded more magnesium. In contrast to traditional methods of tissue solubilization, pepsin digestion is well suited to extraction of magnesium from the small biopsy samples commonly presented for analysis in clinical practice.
Time-resolved immunofluorometric assay of 17 beta-hydroxysteroid dehydrogenase in plasma
Authors: Mäentausta O , Menjivar M , Vihko R 
Published: January 2020

Abstract
We describe a time-resolved immunofluorometric assay (TR-IFMA) for human 17 beta-hydroxysteroid dehydrogenase (17HSD) in which antibody-coated microtiter strip wells and europium chelate-labeled polyclonal antibodies are used. In preparing the label, a polyclonal antibody is affinity-purified and derivatized with diethylenetriamine-pentaacetic acid. With this derivative, five to eight europium ions can be combined with one antibody molecule without decreasing the antibody's immunoreactivity. The minimum detectable concentration of 17HSD is 0.13 microgram/L; the intra- and interassay CVs are less than 8% and less than 15%, respectively, for concentrations between 0.3 and 100 micrograms/L. There is no difference between the concentrations of 17HSD in plasma specimens taken during the proliferative and luteal phases of the menstrual cycle, the measured mean concentration being 0.22 microgram/L. We found no correlation between plasma 17HSD and progesterone concentrations. The plasma concentrations of 17HSD increase during pregnancy, the mean concentrations being 1.5, 4.4, and 12.5 micrograms/L, during the first, second, and third trimesters of pregnancy, respectively. In the specimens from 18 men, the mean concentration was 0.18 microgram/L. In six plasma specimens from patients with endometrial adenocarcinoma, the mean concentration was 0.20 micrograms/L. Pre-analytical aspects are important in the assay of 17HSD because of the lability of the enzyme protein. Preferably, blood should be sampled into EDTA-containing tubes, plasma should be separated within 15 min, and glycerol must be added without delay to a final volume of 200 mL/L.
The "ladder light chain" or "pseudo-oligoclonal" pattern in urinary immunofixation electrophoresis (IFE) studies: a distinctive IFE pattern and an explanatory hypothesis relating it to free polyclonal light chains
Authors: Harrison H H 
Published: January 2020

Abstract
I previously reported the occurrence of a pattern of multiple, equally spaced, low-concentration light chain bands in urine in immunofixation electrophoresis (IFE) studies (Clin Chem 1990;36:1526-7). Although the pattern varies somewhat among patients with regard to the number of bands, light chain type, and concentration, it is relatively invariant with regard to the location and spacing of three prominent kappa bands. The regular spacing of these urinary light chain bands imparts a "ladder rung" or "pseudo-oligoclonal" appearance. High-resolution, two-dimensional electrophoresis of these urine specimens reveals a regularly spaced, isomassic, restricted zonal distribution in the light chain region. These findings may be explained as the results of expression of superfamilies of related, polyclonal, free light chains, which co-migrate because of the limited variety of amino acid substitutions allowed by recombination constraints on light chain genes. This urinary IFE phenomenon is called the ladder light chain (LLC) pattern or pseudo-oligoclonal free light chain pattern to avoid implications of origin from specific clonal proliferation.
Restricted electrophoretic heterogeneity of immunoglobulin light chains in urine: a cause for confusion with Bence Jones protein
Authors: MacNamara E M , Aguzzi F , Petrini C , Higginson J , Gasparro C , Bergami M R , Bianchi G , Whicher J T 
Published: January 2020

Abstract
The detection of Bence Jones protein, an important part of the investigation of suspected myeloma, is most commonly done by agarose or cellulose nitrate electrophoresis followed by immunofixation. Bence Jones protein is recognized as single or multiple bands of one type of light chain. Unfortunately, improvements in sensitivity of these techniques (use of high-affinity antisera and higher resolution electrophoresis) frequently allow detection of multiple light chain bands in the urine of patients who do not have a B-cell dyscrasia. The bands are usually kappa, although they may be accompanied by lambda bands. This pattern may lead to the misdiagnosis of Bence Jones protein and oligoclonal light chain production in patients. Here we show that this pattern is produced by polyclonal light chains; it is present in the urine of all patients with a tubular proteinuria of any etiology and may be induced in healthy individuals by blocking their renal tubular protein reabsorption. Polyclonal light chains separate into monomers and dimers on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and into four major bands with many minor bands by isoelectric focusing. This difference in charge and possibly size results in the banding pattern seen on good-quality electrophoresis and immunofixation.
Statistical criteria for separate reference intervals: race and gender groups in creatine kinase
Authors: Harris E K , Wong E T , Shaw S T 
Published: January 2020

Abstract
Previously published data confirming differences in creatine kinase (EC 2.7.3.2) among various race and gender subgroups in the Los Angeles area have been re-examined with use of recently proposed statistical criteria for defining separate reference intervals. Results indicate that one criterion may be too lenient, whereas another is clearly too restrictive in suggesting the need for separate intervals. Further experience with other analytes in both large and small population samples would be helpful.
Monitoring Cyclosporine in Liver-Transplant Recipients: Effects of Clinical Status on the Performance of Two Monoclonal Antibody-Based Methods
Authors: Tredger Michael J , Gonde Christopher E , Williams Roger 
Published: January 2020

Abstract
The characteristics of the Abbott selective fluorescence polarization immunoassay for cyclosporine in whole blood (TDXSP) were compared with the Incstar radioimmunoassay by using kit standards (INCSP) or TDXSP standards (INCTDX) with samples from adult (48) and pediatric (24) liver-transplant recipients and a further 32 control specimens. The TDXSP assay was faster, less labor intensive, and more precise at higher concentrations; it gave results a median of 5 micrograms/L lower than INCSP values, irrespective of biliary T-tube status, patient's age, or severity of cholestasis in nine patients, comparisons being made for serum bilirubin more than eight times normal or less than 50 mumol/L. However, both assays overestimated INCTDX values by approximately 10%. There was a progressive increase in the ratio of TDXSP to both INCSP and INCTDX results in 57 samples stratified in relation to serum bilirubin concentrations. Cross-reactivity of TDXSP with cyclosporine metabolites M1 (23%) or M17 (12%) was greater than for INCSP (15% and 5%, respectively) or INCTDX (22% and 4%, respectively), but the converse was true with M21 (2% for TDXSP vs 4% and 8%, respectively). Some overestimation of cyclosporine whole-blood concentrations (relative to INCTDX results) may be detected with either the TDXSP (because of cross-reactivity with metabolites) or the INCSP assays (probably because of matrix effects). The similar magnitude of these overestimations suggests that alternative factors such as speed, precision, and cost may influence which method one selects for use in routine monitoring.
Monoclonal Fluorescence Polarization Immunoassay Evaluated for Monitoring Cyclosporine in Whole Blood After Kidney, Heart, and Liver Transplantation
Authors: Winkler M , Schumann G , Petersen D , Oellerich M , Wonigeit K 
Published: January 2020

Abstract
In a prospective study we evaluated a novel fluorescence polarization immunoassay (FPIA) for determining cyclosporine (CsA) in whole blood. FPIA uses a monoclonal antibody and is performed on the TDx (Abbott). The within-series (CV less than 2%) and between-days (CV less than 3.3%) precision of the assay was excellent. The results obtained by the monoclonal FPIA in samples from transplant patients (n = 100) averaged 31.9% and 20.2% higher than those by HPLC and a specific radioimmunoassay (INCStar), respectively. Results by all three methods correlated well. Follow-up studies during the early course after liver transplantation, however, suggested that high metabolite concentrations affect FPIA results. This is explained by previously described cross-reactions of the monoclonal antibody with some CsA metabolites. The FPIA results in samples of such patients should be interpreted cautiously.
Age-Correlated Modifications of Copper-Zinc Superoxide Dismutase and Glutathione-Related Enzyme Activities in Human Erythrocytes
Authors: Ceballos-Picot Iréne , Trivier Jean-Marc , Nicole Annie , Sinet Pierre-Marie , Thevenin Marc 
Published: January 2020

Abstract
To obtain a comprehensive profile of the erythrocyte antioxidant defense potential during aging, we investigated copper-zinc superoxide dismutase (CuZn-SOD), seleno-dependent glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-RD), and glutathione-S-transferase (GSH-S-T) activities in human erythrocytes from 167 apparently healthy subjects, ages one month to 63 years (102 females, 65 males). We found a negative correlation between age and activities of CuZn-SOD (r = 0.362, P less than 0.001), GSSG-RD (r = 0.549, P less than 0.001), and GSH-S-T (r = 0.575, P less than 0.001). In contrast, we found a positive correlation between age and GSH-Px activity (r = 0.401, P less than 0.001). To evaluate aging changes, we divided the subjects into five groups: Group 1 (newborn-age one year), Group 2 (1-11 years), Group 3 (11-25 years), Group 4 (25-40 years), and Group 5 (40-63 years). Significant age-related modifications in erythrocyte enzyme activities appeared in Group 3 for CuZn-SOD, GSSG-RD, and GSH-Px activity, whereas for GSH-S-T activity age-related modifications appeared in Group 2. We found no sex-related differences in erythrocyte CuZn-SOD, GSSG-RD, GSH-Px, and GSH-S-T activities.
Simultaneous Quadruple-Label Fluorometric Immunoassay of Thyroid-Stimulating Hormone, 17 α-Hydroxyprogesterone, Immunoreactive Trypsin, and Creatine Kinase MM Isoenzyme in Dried Blood Spots
Authors: Xu Y Y , Pettersson K , Blomberg K , Hemmilä I , Mikola H , Lövgren T 
Published: January 2020

Abstract
We describe a quadruple-label fluorometric immunoassay for simultaneously measuring four analytes: thyroid-stimulating hormone (TSH), 17 alpha-hydroxyprogesterone (17 alpha-OHP), immunoreactive trypsin (IRT), and creatine kinase MM (CK-MM). The assay is based on immunoreagents labeled with four different lanthanide ions (Eu3+, Tb3+, Sm3+, and Dy3+), on dissociative fluorescence enhancement applying the principle of co-fluorescence, and on time-resolved fluorometry. The monoclonal anti-alpha-TSH and anti-IRT antibodies and the polyclonal anti-CK-MM antibody were labeled with Eu3+, Sm3+, and Dy3+, respectively; 17 alpha-OHP was labeled with Tb3+. The assay was performed in microtitration strip wells coated with a mixture of monoclonal antibodies against beta-TSH, IRT, and CK-MM and a polyclonal goat anti-rabbit IgG for capture of the rabbit anti-17 alpha-OHP antibodies. After completion of the immunoreactions, the bound fractions of the lanthanides were dissociated into the co-fluorescence enhancement solution, creating highly fluorescent chelates. The four lanthanide-specific signals were subsequently measured in a time-resolved fluorometer. The detection limits of the assay were 0.1 mIU/L for TSH, 2 nmol/L for 17 alpha-OHP, 2 micrograms/L for IRT, and 4 U/L for CK-MM.
Homologous Radioimmunoassay of Human Osteocalcin
Authors: Bouillon R , Vanderschueren D , Van Herck E , Nielsen H K , Bex M , Heyns W , Van Baelen H 
Published: January 2020

Abstract
Osteocalcin or bone gamma-glutamic acid-containing protein (GLA protein) was isolated from human bone and used to develop a homologous radioimmunoassay of human osteocalcin. The effect of age on serum osteocalcin was studied in 380 normal children and adolescents and 330 normal adults. The mean (+/- SD) values in adults were higher in men [25 +/- 5 micrograms/L (4.3 +/- 0.8 nmol/L)] than in premenopausal women [20 +/- 6 micrograms/L (3.4 +/- 1.0 nmol/L); P &lt; 0.01], but both were lower than in postmenopausal women [29 +/- 2 micrograms/L (5.0 nmol/L)]. The highest concentrations were seen in girls [ages 10-12 years: 99 +/- 38 micrograms/L (17.0 nmol/L)] and boys [ages 14-16 years: 107 +/- 57 micrograms/L (18.4 nmol/L)]. These mean values were substantially higher than those previously reported for results of heterologous osteocalcin radioimmunoassays but the correlation (r = 0.87, n = 77, P &lt; 0.001) between both sets of results was excellent. In patients with metabolic bone diseases characterized by high or low bone turnover, the increase or decrease in serum osteocalcin observed was as expected. This homologous radioimmunoassay of human osteocalcin thus reflects bone turnover but reports serum concentrations higher than previously suspected.
Flow-Injection Analysis for Malondialdehyde in Plasma with the Thiobarbituric Acid Reaction
Authors: Ikatsu H , Nakajima T , Murayama N , Korenaga T 
Published: January 2020

Abstract
A simple, precise, and rapid method to measure plasma malondialdehyde (MDA) was developed by use of solvent extraction--flow-injection analysis. The reagent solution, containing thiobarbituric acid (TBA), 5 g/L in 100 mL/L phosphoric acid, and extraction solvent (methylisobutyl ketone, MIBK) were propelled with a double-plunger micropump at a flow rate of 0.3 mL/min, and 20 microL of sample was introduced into the reagent stream. After TBA-MDA reactant was extracted into MIBK, the organic phase was continuously separated by a successive phase-separation system equipped with two phase separators, and the absorbance of the TBA-MDA reactant was measured at 532 nm. This approach resulted in excellent sensitivity, a CV of &lt; 1.5%, a good correlation with the conventional manual method, and a sampling frequency of 7 samples/h, suggesting that this semiautomated method is suitable for measuring plasma MDA.
Nonimmunological Assay of Urinary Albumin Based on Laser-Induced Fluorescence
Authors: Kessler M A , Hubmann M R , Dremel B A , Wolfbeis O S 
Published: January 2020

Abstract
We describe the first nonimmunological assay of albumin in urine with a detection limit of 1 mg/L. The method is simple, rapid, and accurate. It is based on the probe Albumin Blue 670, which becomes highly fluorescent on binding to albumin. An inexpensive diode laser was used as the light source for measurement of laser-induced fluorescence. The assay was coupled to a flow-injection analysis system capable of running 20 samples per hour. The working range was 1-100 mg/L, which covered albumin concentrations found in nonpathological urine and in urine with slightly increased albumin. This range makes prediction of nephropathy possible at an early stage. Other serum proteins and hemoglobin do not interfere. The coefficients of variation were &lt; 4% and &lt; 7% within one day and from day to day, respectively. A correlation coefficient of 0.990 (n = 100) was obtained for comparison with the Behring nephelometric assay.