bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytical and clinical evaluation of refractive index-matched anomalous diffraction (RIMAD) for assessment of fetal lung maturation
Authors: Rohlfs E M , Chaing S H , Chapman J F 
Published: January 2020

Abstract
We have evaluated refractive index-matched anomalous defraction (RIMAD) (Dubin SB, Clin Chem 1988;34:938-43) as a potential method for assessment of fetal lung maturity (FLM). This method determines the total light scattered by the surfactant-containing lamellar bodies by subtraction of the A650 from amniotic fluid diluted in glycerol from that of amniotic fluid diluted in distilled water. It is not significantly affected by such contaminating chromogens as hemoglobin and bilirubin up to 2.0 g/L and 11.0 mg/L, respectively. However, the addition of as little as 2.5 microL of erythrocytes as whole blood resulted in significant interference. RIMADs for normal respiratory outcomes (n = 78) ranged from 0.018 to 0.471. RIMADs for respiratory distress syndrome (RDS) outcomes (n = 8) ranged from 0.004 to 0.036. Use of a RIMAD referent value of &gt; 0.040 to indicate maturity yielded sensitivity, specificity, predictive value (PV)RDS, and PVmaturity of 100%, 96.2%, 72.2%, and 100%, respectively. The areas under the receiver-operating characteristic curves were 0.997 for the RIMAD assay, 0.993 (P = 0.3) for the TDx-FLM assay, 0.89 (P = 0.017) for the lecithin/sphingomyelin ratio, and 0.87 (P = 0.023) for the foam stability index.
Quantitative RT-PCR combined with time-resolved fluorometry for determination of BCR-ABL mRNA
Authors: Bortolin S , Christopoulos T K 
Published: January 2020

Abstract
A microtiter well-based quantitative reverse transcriptase-PCR assay for determination of BCR-ABL mRNA, which relies on coamplification of the target with an RNA internal standard (IS), was developed. The hapten digoxigenin (Dig) is incorporated during PCR. Target RNA and IS contain identical primer recognition sites and generate same-sized amplification products distinguishable by hybridization with probes specific to the molecules' central part. The hybrids are determined with an anti-Dig-alkaline phosphatase conjugate with fluorosalicylphosphate as substrate. Fluorescent complexes of fluorosalicylate-Tb(III)-EDTA are measured by time-resolved fluorometry. The ratio of fluorescence values for target and IS is linearly related to initial target RNA in the range of 1000 to 200000 molecules. Samples containing K562 total RNA amidst 1 microgram of RNA from normal cells give fluorescence ratios that are linearly related to 30-10000 K562 cells. CVs for 30, 200, and 900 K562 cells are approximately 11%.
Immunoadsorption assay for bone alkaline phosphatase compared with wheat germ agglutinin precipitation assay in serum from (pre)pubertal girls
Authors: Bouman A A , de Ridder C M , Nijhof J H , Netelenbos J C , Delemarre-vd Waal H A 
Published: January 2020

Abstract
The performance characteristics of two bone alkaline phosphatase (ALP; EC 3.1.3.1) assays, a wheat germ agglutinin (WGA) precipitation assay and a new immunoadsorption assay (IAA), were compared. The within- and between-run imprecision of the IAA (3.6-4.2% and 3.6-7.7%) was comparable with that of the WGA assay. The mean cross-reactivity with liver ALP appeared to be 4% in the WGA assay and 11% in the IAA. The reference ranges in a group of 155 healthy Caucasian (pre)pubertal schoolgirls were: 149-401 U/L (total ALP, 30 degrees C), 105-349 U/L (bone ALP, 30 degrees C, WGA assay), and 58-205 U/L (bone ALP, 25 degrees C, IAA). Comparison of the WGA assay (x) with the IAA (y) demonstrated a correlation coefficient of 0.95 [Deming regression equation: y = (0.56 +/- 0.01)x + (2.0 +/- 1.5); Sy[symbol: see text]x = 5.3 U/L]. Correlation studies of the WGA assay and the IAA results with total ALP demonstrated r = 0.98 and 0.96, respectively.
Multienzyme control serum (Seraclear-HE) containing human enzymes from established cell lines and other sources. 3: Evaluation as candidate working enzyme reference material for gamma-glutamyltransferase
Authors: Eto A , Oishi T , Nakano N I , Chikaura Y 
Published: January 2020

Abstract
Seraclear-HE, containing gamma-glutamyltransferase (GGT, EC 2.3.2.2) derived from the cell culture of a human macrophage cell line, was evaluated as a candidate enzyme reference material (ERM) to calibrate routine methods in terms of a Reference Method for GGT. We have compared this preparation with commercially available materials, including Certified Reference Material 319, at 30 degrees C and 37 degrees C with respect to kinetic properties and with respect to commutability between the Reference Method and each of 15 analytical procedures involving five structurally different donor substrates. GGTs of human origin are far more commutable with reagents of varied types than are GGTs derived from animals. Calibration of 44 patients' sera with Seraclear-HE decreased average intermethod variation from 20% to approximately 4%, whereas GGTs of animal origin showed intermethod variations of approximately 30% with no benefit from calibration. Seraclear-HE is promising as a secondary or working ERM to be used as an intermethod calibrator.
Effect of renal function on serum nitrogen oxide concentrations
Authors: Mackenzie I M , Ekangaki A , Young J D , Garrard C S 
Published: January 2020

Abstract
Nitric oxide is too short-lived to measure in vivo, but its production can be estimated by measuring its stable oxidation products, nitrites and nitrates, in serum. Renal elimination of these ions has been demonstrated, but the effect of renal function on their concentrations in serum is currently unknown. We evaluated serum and urine nitrates + nitrites as serum nitrogen oxides (sNOx), nitrogen oxide (NOx) clearance, and creatinine clearance in 71 patients on the Intensive Therapy Unit. The correlation between sNOx and plasma creatinine was strong and highly significant (P &lt;0.001). These results suggest that renal function has a significant effect on sNOx concentrations. Studies in which the sNOx concentration is used as an index of nitric oxide production can therefore be interpreted only if renal function has been taken into account.
Plasma phospholipid fatty acids in X-linked adrenoleukodystrophy
Authors: Aveldaño M I , Donnari D 
Published: January 2020

Abstract
Blood cell and plasma lipid classes and their fatty acids were analyzed in a child with X-linked adrenoleukodystrophy. The increase in saturated fatty acids with very long chains typical of this disease occurred almost exclusively in sphingomyelin. In this lipid, the proportion of lignoceric (24:0) and hexacosanoic (26:0) acids increased while that of 18:0, 20:0, and 24:1 decreased. In the rest of the lipid classes, but especially in cholesteryl esters and triacylglycerols, the proportion of linoleate (18:2) decreased while that of oleate (18:1) increased. In glycerophospholipids, polyunsaturated fatty acids such as 20:4n-6, 22:5n-6, and 22:6n-3 were reduced while their immediate precursors, 20:3n-6, 22:4n-6, and 22:5n-3, respectively, were relatively increased, suggesting a defect in fatty acid desaturation mechanisms. Although less pronounced, a similar trend of changes was seen in the patient's mother; in both, all alterations were more marked in serum than in blood cells.
Physical activity releases prostate-specific antigen (PSA) from the prostate gland into blood and increases serum PSA concentrations
Authors: Oremek G M , Seiffert U B 
Published: January 2020

Abstract
Determination of prostate-specific antigen (PSA) is an established tool in detecting prostate cancer. However, the effect of physical activity on the PSA concentration in serum is controversial. We measured serum concentrations of PSA and prostatic acid phosphatase (PAP) in 301 healthy outpatients before and after they performed standardized exercise. Immediately after 15 min of exercise on a bicycle ergometer, their serum PSA concentrations increased by as much as threefold. The increase was age dependent and correlated to the PSA concentration before exercise. This increase was evident in both the free and complexed fractions of PSA. The amount of PSA secreted into blood depends on the volume of the prostate, whereas productivity of the prostate epithelium remains constant or increases slightly with age. We present cutoff values for clinical use. PAP was also increased, but to a lesser extent. The PSA and PAP secretion mechanisms differ. Our data suggest that extensive physical activity should be avoided before blood sampling for diagnostic purposes and, in case of an increase, the PSA concentration should be controlled after an exercise test.
Two-stage procedure for evaluating interassay carryover on random-access instruments
Authors: Schlain B , Frush H , Pennington C , Osikowicz G , Ford K 
Published: January 2020

Abstract
A two-stage statistical procedure based on Dunnett's multiple comparison procedures with a control has been developed for detecting interassay carryover biases on the Abbott AxSYM(TM) System, a random- and continuous-access immunoanalyzer. With this procedure, every potential source of interassay carryover can be tested and estimated. In minimizing required sample sizes, the first stage is used primarily to detect and eliminate from further testing the assay reagent sources that do not cause carryover biases and the assay sources that cause very large carryover biases. Retested more extensively in the second testing stage are the cases where the data from the first testing stage are insufficient for judgment. An example data set from the Abbott AxSYM Free T4 assay is used to illustrate the methodology.
Serum total testosterone: immunoassay compared with negative chemical ionization gas chromatography-mass spectrometry
Authors: Fitzgerald R L , Herold D A 
Published: January 2020

Abstract
We have developed an electron capture negative chemical ionization gas chromatography-mass spectrometry (GC-MS) procedure to quantify serum testosterone in the clinically relevant range 0.69-69.3 nmol/L and used this procedure to assess Ciba Corning Diagnostics ACS:180 testosterone immunoassay. The GC-MS method involves liquid-liquid extraction of serum samples and synthesis of a pentafluorobenzyloxime/silyl ether derivative of testosterone with excellent chromatographic and electron capturing properties. The ACS testosterone assay is the first fully automated nonradioactive testosterone immunoassay approved by the US Food and Drug Administration. Patients' specimens (101, 57 males, 44 females) were analyzed by both techniques. A plot of the GC-MS (x) vs ACS (y) testosterone concentrations for men was linear (y = 1.07x + 0.19 nmol/L), showing excellent correlation (r2 = 0.98) between the two assays. Agreement of the two assays for female specimens was poor (y = 0.72x + 1.2 nmol/L), with a poor correlation (r2 = 0.31).
Internet: road to heaven or hell for the clinical laboratory?
Authors: Chou D 
Published: January 2020

Abstract
The Internet started as a research project by the Department of Defense Advanced Research Projects Agency for networking computers. Ironically, the networking project now predominantly supports human rather than computer communications. The Internet's growth, estimated at 20% per month, has been fueled by commercial and public perception that it will become an important medium for merchandising, marketing, and advertising. For the clinical laboratory, the Internet provides high-speed communications through e-mail and allows the retrieval of important information held in repositories. All this capability comes at a price, including the need to manage a complex technology and the risk of instrusions on patient privacy.
Defining the smallest analyte concentration an immunoassay can measure
Authors: Brown E N , McDermott T J , Bloch K J , McCollom A D 
Published: January 2020

Abstract
An immunoassay's minimal detectable concentration (MDC), the smallest analyte concentration the assay can reliably measure, is one of its most important properties. Bayes' theorem is used to unify the five current mathematical MDC definitions. The unified definition has significant implications for defining positive results for screening and diagnostic tests, setting criteria for immunoassay quality control and optimal design, reliably measuring biological substances at low concentrations, and, in general, measuring small analyte concentrations with calibrated analytic methods. As an illustration, we apply the unified definition to the microparticle capture enzyme immunoassay for prostate-specific antigen (PSA) developed for the Abbott IMx automated immunoassay system. The MDC of this assay as estimated by our unifying approach is shown to be 4.1-7.1 times greater than currently reported. As a consequence, the ability of the assay to measure reliably small concentrations of PSA to detect early recurrences of prostate cancer is probably overstated.
Immunoassay for intact amino-terminal propeptide of human type I procollagen
Authors: Melkko J , Kauppila S , Niemi S , Risteli L , Haukipuro K , Jukkola A , Risteli J 
Published: January 2020

Abstract
We have developed quantitative immunoassays for the intact, trimeric amino-terminal propeptide of human type I procollagen (PINP) and its Col1 domain. Intact PINP was isolated from the pleural fluids of cancer patients by a combination of ion-exchange, gel-filtration, and reversed-phase chromatographies. The amino-terminal Col1 domain of PINP was isolated after bacterial collagenase treatment of the heat-denatured trimeric propeptide. For the intact PINP assay we used a polyclonal antibody with only 1.2% cross-reaction with the monomeric Col1 domain. In human serum, this assay detects only one peak of PINP antigenicity that has the size of known intact PINP. Under similar conditions, an assay for the Coll domain of PINP recognized two circulating antigens. The biological relevance was further verified in wound fluid. Interassay and intraassay CVs were 3.1-9.3% for values within the reference intervals (mean +/- 2SD) for intact PINP in serum, which were 19-84 microg/L for women and 20-76 microg/L for men.
Analytical performance and clinical utility of a direct LDL-cholesterol assay in a hyperlipidemic pediatric population
Authors: Harris N , Neufeld E J , Newburger J W , Ticho B , Baker A , Ginsburg G S , Rimm E , Rifai N 
Published: January 2020

Abstract
This study compares a new latex immunoseparation method for the direct determination of plasma low-density lipoprotein cholesterol (LDL-C) with the reference procedure for LDL-C (beta-quantification) in a pediatric hyperlipidemic population. The direct LDL-C assay has a mean bias of -98 mg/L in a fasting group (n = 96) of patients (mean triglycerides 1057 +/- 720 mg/L) and a bias of +177 mg/L in a nonfasting group (n = 42, mean triglycerides 4854 +/- 5457 mg/L). The mean total analytical error calculated from our data is 13.8%. The direct LDL-C assay and the commonly used Friedewald calculation respectively classified 81% and 84% of fasting patients correctly, according to the cutoffs of 1100 and 1300 mg/L for LDL-C set by the National Cholesterol Education Program for pediatric patients. Of combined fasting and nonfasting patients, 80% were correctly classified by the direct LDL-C assay. Therefore, despite several analytical shortcomings, the direct LDL-C assay may be useful in managing hyperlipidemic children without the need for a fasting specimen.
Accumulation of arsenic species in serum of patients with chronic renal disease
Authors: Zhang X , Cornelis R , De Kimpe J , Mees L , Vanderbiesen V , De Cubber A , Vanholder R 
Published: January 2020

Abstract
Speciation of arsenic was determined in serum of 19 non-hemodialysis (non-HD) and 18 HD patients. The respective mean values of serum creatinine in these groups were 410 +/- 250 and 914 +/- 173 mumol/L (reference range for healthy subjects: females 50-80; males 57-93 mumol/L). The mean total arsenic concentrations were 5.12 +/-5.58 and 6.47 +/- 4.28 micrograms/L, respectively (reference value: 0.958 +/-1.52 micrograms/L). Dimethylarsinic acid (DMA) and arsenobetaine (AsB) were the major As species in serum of the non-HD and HD patients, with mean values of 0.82 +/- 1.05 and 1.93 +/- 1.51 micrograms/L for DMA and 3.55 +/- 4.58 and 3.47 +/- 2.89 micrograms/L for AsB, respectively. Serum concentrations of inorganic As and monomethylarsonic acid in both groups were below the detection limits for these compounds. Measurement of As concentration before vs after 4 h of HD treatment indicated that 68% of total As in serum was removed, as was 16% of the total As in packed cells. The efficiency of DMA and AsB removal during dialysis corresponded to that of total As.
Determination of dexamethasone in saliva
Authors: Thijssen J H , Gispen-de Wied C C , van Heeswijk G M , Veeman W 
Published: January 2020

Abstract
We conducted experiments to demonstrate that the determination of dexamethasone in saliva is a valuable tool to assess dexamethasone concentrations in the body after administration of this synthetic corticosteroid. After extraction of saliva, a RIA involving highly specific commercially available antibodies was established and evaluated. This RIA was easy to conduct, reliable, and sensitive enough to measure dexamethasone until approximately 24 h after oral administration of 1 mg per 70 kg of body weight. On the morning after the administration, the mean concentration in saliva was 540 pmol/L. Over a large range (10(3)-10(6) pmol/L), plasma concentrations correlated very well with salivary concentrations; plasma contained six times more dexamethasone than saliva.
DNA-based carrier screening in primary healthcare: screening for aspartylglucosaminuria mutations in maternity health offices
Authors: Hietala M , Aula P , Syvänen A C , Isoniemi A , Peltonen L , Palotie A 
Published: January 2020

Abstract
Large-scale genetic screening programs are complex enterprises in which ethical, technical, medical, and socioeconomic aspects have to be handled with professional expertise. Establishment of automated, relatively robust, and inexpensive laboratory techniques is one step of this path. Here a pilot carrier-screening program for the mutations causing aspartylglucosaminuria was carried out for pregnant women in primary care maternity health offices. Women (1975) were tested before their 12th week of pregnancy, and 31 heterozygotes were detected. The sampling was based on dried blood strips, facilitating convenient handling and inexpensive mailing to the laboratory. The mutation detection technique, solid-phase mini-sequencing simplified by the use of scintillation microplates and automated equipment, proved to be rapid, simple, inexpensive, and reliable, with a low repeat rate (2.5%). In conclusion, we found that good collaboration between the primary healthcare unit, the laboratory, and counseling experts, combined with modern laboratory technology, facilitate reliable low-cost genetic testing.
Validation of an enzymatic total magnesium determination based on activation of modified isocitrate dehydrogenase
Authors: Stone M J , Chowdrey P E , Miall P , Price C P 
Published: January 2020

Abstract
We have evaluated an enzymatic assay for the determination of Mg in serum, based on the activation of a chemically modified form of isocitrate dehydrogenase by Mg2+. In the presence of potassium isocitrate and NADP+, NADPH, which absorbs light at 340 nm, is produced, and its increase is proportional to Mg2+ in the sample. We have shown linearity to at least 5 mmol/L Mg and good precision by within-run CVs between 1.4% and 3.5% and day to day CVs between 3.2% and 5.4%. The method (y) is accurate, comparing well with the xylidyl blue method (x), with a Deming regression of y = 0.930x - 0.063 (r = 0.98, S(y/x) = 0.019), and with atomic absorption spectrophotometry (x), with a Deming regression of y = 0.932x - 0.016 (r = 0.97, S(y/x) = 0.023), and shows no interference from common endogenous compounds in blood and various metal ions except for visibly hemolyzed samples. A rapid assay, with reagents that are stable for at least 30 days at 4 degrees C and requiring no prior preparation, it is simple to use and suitable for adaptation onto automated chemistry analyzers.
High-Accuracy Determination of Microsatellite Instability Compatible with Liquid Biopsies
Authors: Silveira Amanda Bortolini , Bidard François-Clément , Kasperek Amélie , Melaabi Samia , Tanguy Marie-Laure , Rodrigues Manuel , Bataillon Guillaume , Cabel Luc , Buecher Bruno , Pierga Jean-Yves , Proudhon Charlotte , Stern Marc-Henri 
Published: January 2020

AbstractBackgroundMicrosatellite instability (MSI) has recently emerged as a predictive pan-tumor biomarker of immunotherapy efficacy, stimulating the development of diagnostic tools compatible with large-scale screening of patients. In this context, noninvasive detection of MSI from circulating tumor DNA stands as a promising diagnostic and posttreatment monitoring tool.MethodsWe developed drop-off droplet-digital PCR (ddPCR) assays targeting BAT-26, activin A receptor type 2A (ACVR2A), and defensin beta 105A/B (DEFB105A/B) microsatellite markers. Performances of the assays were measured on reconstitution experiments of various mutant allelic fractions, on 185 tumor samples with known MSI status, and on 72 blood samples collected from 42 patients with advanced colorectal or endometrial cancers before and/or during therapy.ResultsThe 3 ddPCR assays reached analytical sensitivity &lt;0.1% variant allelic frequency and could reliably detect and quantify MSI in both tumor and body fluid samples. High concordance between MSI status determination by the three-marker ddPCR test and the reference pentaplex method were observed (100% for colorectal tumors and 93% for other tumor types). Moreover, the 3 assays showed correlations with r ≥ 0.99 with other circulating tumor DNA markers and their dynamic during treatment correlated well with clinical response.ConclusionsThis innovative approach for MSI detection provides a noninvasive, cost-effective, and fast diagnostic tool, well suited for large-scale screening of patients that may benefit from immunotherapy agents, as well as for monitoring treatment responses.
Bayesian-Based Spectrum Sensing and Optimal Channel Estimation for MAC Layer Protocol in Cognitive Radio Sensor Networks
Authors: Maisuria Jemish V , Mehta Saurabh N 
Published: January 2020

Abstract
Cognitive radio (CR) is an intelligent and adaptive radio technology that automatically detects the available channels in the wireless spectrum and sometimes changes the transmission parameters to enable effective communication. Spectrum sensing in CR prevents harmful interference with the licensed users and maximizes the spectrum utilization. Thus, this paper proposes a technique for optimal channel estimation and spectrum sensing for MAC layer protocol in CR networks such that the scheduling issues are addressed. Initially, in the CR networks, spectrum sensing is done using the proposed optimal naive Bayes classifier (ONBC) based on the signal statistics, such as energy and likelihood ratio. The ONBC is developed by integrating the bat–bird swarm algorithm (BBSA) with the naive Bayes classifier, which works based on the Bayesian concept. The BBSA is newly developed by integrating the bird swarm algorithm (BSA) and bat algorithm. Finally, the channel estimation is done using the pilot-based sequential procedure and least square estimation (LSE). The analysis of the proposed method is done in the Rayleigh and Rician environments using 256 and 512 sub-carriers. From the results, it is exposed that the proposed BBSA + LSE pilot-based sequential method obtains the bit error rate, normalized energy and Probability detection (PD) of is 0.0126, 0.8446 and 0.9355, respectively.