bluuebunny/crossref_metadata_2025_split huggingface dataset:
Passage of silver ions through membrane-mimetic materials, and its relevance to treatment of burn wounds with silver sulfadiazine cream
Authors: Tsipouras Nicholas , Rix Colin J , Brady Peter H 
Published: January 2020

AbstractTreatment of acute burn wounds with silver sulfadiazine has raised concern of potential silver toxicity. As the wound heals, a barrier forms between the silver sulfadiazine and the blood, but this membrane is not impenetrable, and so silver absorption is still possible. In this work, we have modeled chemical systems to investigate the transport of silver sulfadiazine and silver chloride through cellulose, chitosan, collagen, and polyethylene membranes into the following media: synthetic serum electrolyte solution (SSES), SSES plus glutathione, and human serum, to simulate some of the chemical processes occurring at a burn wound during healing. Our results clearly indicate that membranes can retard the movement of silver ions, especially those that have silver-binding properties. This suggests that silver absorption at a healing wound will be minimized by entrapment of silver in the growing membrane network, and thus the likelihood of silver toxicity will be reduced.
Optical tweezers-based immunosensor detects femtomolar concentrations of antigens
Authors: Helmerson Kristian , Kishore Rani , Phillips William D , Weetall Howard H 
Published: January 2020

Abstract
We used optical tweezers (optical trapping technology) to measure the force required to separate antigen–antibody bonds. Under competitive-binding conditions, we used the force determination to detect and measure protein antigen concentrations as small as 1 fmol/L (10−15 mol/L).
Single-strand conformation polymorphism analysis with high throughput modifications, and its use in mutation detection in familial hypercholesterolemia
Authors: Humphries Steve E , Gudnason Vilmundur , Whittall Ros , Day Ian N M ,   for the International Federation of Clinical Chemistry Scientific Divison: Committee on Molecular Biology Techniques
Published: January 2020

Abstract
The identification of the specific mutation causing an inherited disease in a patient is the framework for the development of a rationale for therapy and of DNA-based tests for screening relatives. We present here a review of the single-strand conformational polymorphism (SSCP) method, which allows DNA fragments that have been amplified with specific primers and PCR to be scanned rapidly for any sequence variation. The general principles of the method are described, as are the major factors that must be considered in developing an optimal SSCP strategy, namely the length of the PCR fragment and the temperature of the gel run. Options for sample denaturing gel characteristics and detection of DNA fragments are discussed. In addition, several modifications are presented that have been developed for high-throughput mutational analysis. The application of these techniques to screen for mutations in the LDL receptor gene in patients with familial hypercholesterolemia are described.
Reversible myocardial ischemic injury is not associated with increased creatine kinase activity in plasma
Authors: Ishikawa Yuichi , Saffitz Jeffrey E , Mealman Terrence L , Grace Ann M , Roberts Robert 
Published: January 2020

Abstract
Creatine kinase (CK) isoenzymes MM, MB, and BB are located primarily in the cell cytosol, and increased CKMB in plasma is the hallmark of myocardial infarction. However, whether CK is released with reversible ischemic injury remains controversial. Here, we assessed plasma CK activity—cytosolic and mitochondrial CK—in serial samples (every 10 min for 60 min, then hourly or every 4 h for 48 h) from 46 conscious dogs after transient or sustained coronary occlusion. Four dogs were sham-operated (controls); four underwent sustained coronary occlusion (96 h); and 38 underwent transient coronary occlusion (10–40 min) followed by 48 h of reperfusion. In postmortem histological examination of the dogs’ hearts by light and electron microscopy, we looked for ischemia or necrosis. The presence of cell swelling and glycogen depletion was indicative of ischemia, whereas the added presence of cell disruption indicated necrosis. Coronary occlusion for ≥20 min consistently increased plasma mitochondrial and total CK activity and produced histologically evident myocardial necrosis. In contrast, after 10 to 15 min of coronary occlusion, 12 of 14 animals, despite extensive severe reversible ischemia, showed no increase in plasma CK; the remaining 2, which had increased plasma CK, had subendocardial necrosis. Thus, cytosolic or mitochondrial CK is released from the heart only when there has been irreversible myocardial injury—a finding with significant diagnostic and therapeutic implications.
Clinical evaluation of the Byk LIA-mat CA125 II assay: discussion of a reference value
Authors: Bonfrer Johannes M G , Korse Catharina M , Verstraeten Rob A , van Kamp Gerard J , Hart Guus A M , Kenemans Peter 
Published: January 2020

Abstract
The Byk LIA-mat CA125 II assay was compared with the Centocor IRMA CA125 II. Serum samples studied (n = 1012) were obtained from 652 apparently healthy females, 61 pregnant women, and 299 patients with benign and malignant gynecological tumors. The CA125 II assay value at the 95th percentile of the total healthy group was 29 kU/L for the LIA-mat and 32 kU/L for the Centocor assay. For the LIA-mat assay the 95th percentile was 31 kU/L (Centocor 36 kU/L) for the group &lt;45 years and 21 kU/L (Centocor 25 kU/L) for women &gt;55 years of age. By using ROC curves we found the optimal pretreatment Byk LIA-mat CA125 II value differentiating between benign and malignant ovarian tumors to be 95 kU/L. Pretreatment CA125 values &gt;1000 kU/L were detected in serum samples of patients with advanced epithelial ovarian cancer.
Application of isotope-selective nondispersive infrared spectrometry (IRIS) for evaluation of [13C]octanoic acid gastric-emptying breath tests: comparison with isotope ratio–mass spectrometry (IRMS)
Authors: Schadewaldt Peter , Schommartz Bernd , Wienrich Gregor , Brösicke Herbert , Piolot Ralf , Ziegler Dan 
Published: January 2020

Abstract
Suitability of isotope-selective nondispersive infrared spectrometry (IRIS) for evaluation of [13C]octanoic acid gastric-emptying breath test was assessed and compared with standard isotope ratio–mass spectrometry (IRMS). The estimated bias of IRMS and IRIS measurements of baseline-corrected 13CO2exhalation amounted to ± 0.1 and ± 0.6 Δδ values (n = 360), respectively. In breath tests performed on 60 diabetic patients, the gastric emptying parameters were calculated by nonlinear regression analysis of the time course of 13CO2exhalation: half-emptying time (t1/2,breath, 90 ± 39 min), lag phase (tlag,breath, 34 ± 27 min), and gastric emptying coefficient (GEC, 2.9 ± 0.5). A reasonable linear correlation was found between the two methods (y = IRIS, x = IRMS) with respect to Δδ values (y = 0.35 + 0.92x, r = 0.985, Sy|x = ±0.6, n = 1116) and a rather good agreement of the computed gastric emptying parameters was obtained (t1/2,breath: y = 0.99x + 4.06, Sy|x = ±6.3; tlag,breath: y = 0.97x + 0.96, Sy|x = ±3.4; GEC: y = 0.97x − 0.01, Sy|x = ±0.09).
Enzymatic assay of d-mannose in serum
Authors: Etchison James R , Freeze Hudson H 
Published: January 2020

Abstract
We describe a new and improved enzymatic assay for determining the concentration of d-mannose in sera. Serum d-glucose is selectively converted to glucose-6 phosphate with the highly specific thermostable glucokinase (EC 2.7.1.2) from Bacillus stearothermophilus. The anionic reaction products and excess substrates are removed by a rapid and simple anion-exchange chromatography step in microcentrifuge spin columns. d-Mannose in the glucose-depleted sample is then assayed spectrophotometrically by using coupled enzymatic reactions. The quantitative elimination of glucose from the serum samples allowed the accurate and reproducible assay of serum mannose in the 0–200 μmol/L range. Recovery of mannose added to serum (5–200 μmol/L) was 94% ± 4.4%. The intraassay CV was 6.7% at 40 μmol/L mannose (n = 5; 39.6 ± 1.6 μmol/L) and 4.4% at 80 μmol/L (n = 11; 75.0 ± 1.8 μmol/L); the interassay CV at these concentrations was 12.2% (n = 7; 36.9 ± 2.1 μmol/L) and 9.8% (n = 7; 74.2 ± 2.7 μmol/L), respectively. Sera from 11 healthy human volunteers contained an average of 54.1 ± 11.9 μmol/L mannose (range 36–81 μmol/L).
New sandwich ELISA for human urinary N-acetyl-β-d-glucosaminidase isoenzyme B as a useful clinical test
Authors: Numata Yoshito , Morita Atsushi , Kosugi Yoko , Shibata Kazunori , Takeuchi Nozomu , Uchida Kiyohisa 
Published: January 2020

AbstractWe have developed a new ELISA for quantifying N-acetyl-β-d-glucosaminidase (NAG) isoenzyme B in human urine after raising monoclonal antibodies against the isoenzyme from human placenta. Though the obtained antibodies reacted not only to isoenzyme B but also to A, we could detect isoenzyme B selectively by a two-step sandwich ELISA with a pair of selected antibodies at low pH in the first reaction. The detected limit was 0.5 μg/L for a sample volume of 25 μL. Within-run CVs ranged from 2.5% to 5.4% and between-run CVs ranged from 6.2% to 9.1%. Recoveries of NAG isoenzyme B added to each of three urine samples ranged from 91% to 114%. The dilution curves of urine samples showed good linearity. The cross-reactivity of NAG isoenzyme A was practically negligible (2–3%). The mean value for NAG isoenzyme B in spot urines from healthy adults was 2.9 μg/g creatinine. This ELISA method is rapid and precise enough for routine determination of NAG isoenzyme B in human urine.
Quality-control (QC) performance measures and the QC planning process
Authors: Parvin Curtis A 
Published: January 2020

Abstract
Numerous outcome measures can be used to characterize and compare the performance of alternative quality-control (QC) strategies. The performance measure traditionally used in the QC planning process is the probability of rejecting an analytical run when a critical out-of-control error condition exists. Another performance measure that naturally fits within the total allowable error paradigm is the probability that a reported test result contains an analytical error that exceeds the total allowable error specification. In general, the out-of-control error conditions associated with the greatest chance of reporting an unacceptable test result are unrelated to the traditionally defined “critical” error conditions. If the probability of reporting an unacceptable test result is used as the primary performance measure, worst-case QC performance can be determined irrespective of the magnitude of any out-of-control error condition that may exist, thus eliminating the need for the concept of a “critical” out-of-control error.
Quantitative colorimetric determination of urinary p-aminophenol with an automated analyzer
Authors: Van Bocxlaer Jan F , Clauwaert Karine M , Lambert Willy E , De Leenheer André P 
Published: January 2020

Abstract
We developed an automated colorimetric method for the quantitative determination of p-aminophenol with a Cobas Mira analyzer. The procedure can be used for the biological monitoring of human exposure to aniline. An absorbed aniline dose is extensively oxidized to p-aminophenol, which is excreted in urine mainly as glucurono- and sulfo- conjugates. After enzymatic hydrolysis, we reacted the free compound with resorcinol in the presence of manganese ions to form an indophenol dye, which is measured at 550 nm. Excellent accuracy (102.8%, 103.9%, and 96.8% at 2.5, 50, and 90 mg/L, respectively) and precision (7.7%, 2.1%, and 0.8% CV for within-run and 11.1%, 4.7%, and 4.6% for total reproducibility at 2.5, 50, and 90 mg/L, respectively) were achieved over a linear concentration range of 2.0 to 100 mg/L. The detection limit was 0.9 mg/L and no significant interference (except for o-aminophenol) was found for several investigated drugs and related compounds. The proposed method was used for a stability study and to analyze several samples from an occupational health screen.
Interference with testing for lysergic acid diethylamide
Authors: Ritter Detlef , Cortese Cherise M , Edwards Linda C , Barr Judith L , Chung Hyung D , Long Christopher 
Published: January 2020

Abstract
We found a high rate (4.2%) of positive results for lysergic acid diethylamide (LSD) by Emit in 1898 urine samples that were submitted primarily from psychiatric patients for drugs-of-abuse (DOA) testing. Specimens that tested positive for LSD by Emit subsequently tested negative for LSD with two RIAs. Furthermore, LSD was not detected in randomly selected Emit-positive urine samples by gas chromatography–mass spectrometry. Normal urine samples tested positive for LSD by Emit when they were supplemented with therapeutic medications that were prescribed for patients with positive urine LSD results by Emit. These therapeutic drugs interfered specifically with the Emit assay for LSD, since other Emit DOA tests were not affected by these medications at the tested concentrations.
Detection of anabolic steroid administration: ratio of urinary testosterone to epitestosterone vs the ratio of urinary testosterone to luteinizing hormone
Authors: Perry Paul J , MacIndoe John H , Yates William R , Scott Shane D , Holman Timothy L 
Published: January 2020

Abstract
Our goal in this study was to determine whether the urinary ratio of testosterone to luteinizing hormone (T/LH) as an indicator of exogenous anabolic steroid (AS) use is superior to the urinary ratio of testosterone to epitestosterone (T/E). After 2 weekly placebo injections, 19 subjects were given testosterone cypionate (TC) injections of 250 or 500 mg/week for 14 weeks followed by 14 weekly placebo injections. Patients were considered to have ceased taking TC if they tested negative 9 weeks after their last injection. For detection of illicit or supraphysiological TC (AS) use, the urinary T/E ratio of ≥6 yielded a false-negative rate of 46% and a false-positive rate of 4%. However, a urinary T/LH ratio of ≥30 produced a false-negative rate of only 24% and a false-positive rate of 13%. We conclude that the urinary T/LH ratio of ≥30 is a more sensitive marker of AS use than the urinary T/E ratio of ≥6 and remains sensitive for twice as long as urinary T/E.
Microdialysis-HPLC for plasma levodopa and metabolites monitoring in parkinsonian patients
Authors: Dethy Sophie , Laute Marie Aline , Van Blercom Nadège , Damhaut Philippe , Goldman Serge , Hildebrand Jerzy 
Published: January 2020

Abstract
We used in vitro microdialysis-HPLC to determine l-3,4-dihydroxyphenylalanine (l-DOPA) and its metabolites in plasma of patients with advanced Parkinson disease. Blood samples and clinical evaluations were obtained 0, 30, 60, 90, 120, and 150 min after oral administration of carbidopa/l-DOPA (25/100 mg, 12.5/125 mg, and 50/200 mg). In vitro recoveries for l-DOPA and metabolites ranged from 22% to 36%. Linear correlation was found between metabolite concentrations in the dialysate and in the surrounding medium. There was a significant positive correlation between l-DOPA dose and plasma concentration of l-DOPA and homovanillic acid (P &lt;0.04). Clinical response was maximum 60 min after l-DOPA administration. Threshold l-DOPA plasma concentration averaged 7.74 ± 3.3 μmol/L. Motor effect is longer with the highest l-DOPA peak concentration (P &lt;0.01). Microdialysis-HPLC is readily applicable, reproducible, and allows monitoring of plasma l-DOPA and metabolites in parkinsonian patients.
Potential of electrospray mass spectrometry for quantifying glycohemoglobin
Authors: Roberts Norman B , Green Brian N , Morris Michael 
Published: January 2020

AbstractAn electrospray ionization–mass spectrometric procedure has been developed for determining glycohemoglobin. Whole-blood samples from 78 diabetic and 50 nondiabetic subjects (glycation range 3–15%, as determined by electrospray mass spectrometry) were diluted 500-fold in an acidic denaturing solvent and introduced directly into a mass spectrometer. The resulting mass spectra were then processed to estimate the percentage of glycohemoglobin present in the sample. Total analysis time, including plotting the spectra and computing the percentage of glycation, was ∼3 min. The imprecision (CV) of the method was &lt;5.1% for inter- and intrabatch analyses for total glycohemoglobin in the range 3.6–14%. Comparison of the mass spectrometric results with those from established affinity chromatographic procedures showed good overall agreement. The relative glycation of the α- and β-chains was determined directly and was shown to be constant (0.64:1) over the glycation range measured. Only single glucose attachment to both the α- and β-chains was observed.
Accurate and precise isotope dilution mass spectrometry method for determining glucose in whole blood
Authors: Hannestad Ulf , Lundblad Arne 
Published: January 2020

Abstract
An accurate and precise method to determine glucose concentration in whole blood is presented. The method, based on isotope dilution gas chromatography–mass spectrometry (ID GC-MS), was developed to be used as a Reference Method for determining glucose concentration in capillary or venous whole blood. Blood samples and standards are pipetted manually with “microcap” micropipettes, which makes it possible to collect samples even at the patient’s bedside. Glucose is quantified as its aldononitrile pentaacetate. [13C6]Glucose is used as an internal standard. Assay of Seronorm and Pathonorm L and H controls by ID GC-MS gave within-run CVs of 0.66%, 0.96%, and 0.92%, respectively. For whole blood with glucose concentrations in the low, normal, and high ranges, the within-run CVs were 1.27%, 0.91%, and 0.78%, respectively. The between-run CV for glucose calculated from 36 separate single analyses of Seronorm was 1.44%. In an accuracy assessment test of the HemoCue blood glucose analyzer, 140 capillary blood samples were measured in parallel after split-sampling. For all samples the HemoCue analyzer results had a mean bias of +2.0% compared with the ID GC-MS results.
Modified and improved anti-acetylcholine receptor (AChR) antibody assay: comparison of analytical and clinical performance with conventional anti-AChR antibody assay
Authors: Ferrero Bruno , Aimo Giuseppe , Pagni Roberto , Bergamasco Bruno , Bongioanni Maria R , Bergamini Lodovico , Durelli Luca 
Published: January 2020

Abstract
We developed a modified anti-acetylcholine receptor (AChR) antibody (Ab) assay based on a radioreceptor assay and a calibration curve. We compared the analytical and clinical performances of this modified assay with those of the conventional anti-AChR Ab radioreceptor assay. Serum specimens were from patients with myasthenia gravis (MG) (n = 156) and from control subjects (n = 106). The modified assay demonstrated lower within-assay (4.0–6.6%) and between-assay (5.3–7.8%) CVs, greater linearity, lower cost, and shorter assay time than the conventional method. ROC curve analysis indicated almost identical specificity and sensitivity (&gt;0.92) for these two anti-AChR Ab assays. The modified and conventional assays were also equivalent for blocking anti-AChR Ab assay. Moreover, the modified anti-AChR Ab assay, differently from the conventional assay, allowed us to reveal anti-AChR Ab concentration differences among different clinical grades of MG.
Determination of d-lactate by enzymatic methods in biological fluids: study of interferences
Authors: Martí Ramon , Varela Encarna , Segura Rosa M , Alegre José , Suriñach José M , Pascual Carles 
Published: January 2020

Abstract
Analysis of nondeproteinized samples with an enzymatic method to determine d-lactate indicated interferences. The presence of l-lactate dehydrogenase (LD) and l-lactate in the sample led to underestimation of d-lactate content when a sample blank was processed and overestimation when it was omitted. We proved that this interference is not due to lack of d-LD stereospecificity. Moreover, assessment of d-LD and l-LD KM for NAD+ allowed us to rule out the different affinities for this coenzyme as a cause of the interference. Our results underline the importance of deproteinizing samples for d-lactate analysis when enzymatic methods are used. The ultrafiltration procedure we propose is convenient and shows acceptable mean recovery (108%) and good imprecision (within-run CV = 4.2% and 3.0% for d-lactate at 31 and 107 μmol/L, respectively; between-run CVs were 7.3% at 49 μmol/L d-lactate and 3.1% at 115 μmol/L d-lactate).
Free triiodothyronine concentration in serum of 1050 euthyroid children is inversely related to their age
Authors: Verheecke Paul 
Published: January 2020

Abstract
Free triiodothyronine was assayed in serum of 1050 euthyroid children with the Amerlex-MAB method. We studied 50 samples for each year of age, from &lt;1 to 20, and no child had more than one sample taken. A gradient of values was observed, increasing by 31% from 5.04 pmol/L as the mean of 20-year-old patients to 6.59 pmol/L in the serum of children younger than 1 year. For practical reasons the lower normal limit was proposed to remain at 3.4 pmol/L for all patients; the higher limit can be set at 8.3 (0 to 3 years), 7.8 (4 to 7 years), 7.1 (8 to 11 years), 6.8 (12 to 15 years), and 6.7 (16 to 19 years). Preferably, the regression line of the mean + 2 SD can be used, resulting in a high normal limit of 8.3 pmol/L at birth to 6.3 pmol/L at 20 years, decreasing by 0.1 pmol/L per year.
Evaluation of the Menarini–Arkray HA 8140 hemoglobin A1c analyzer
Authors: John W Garry , Braconnier Francois , Miedema Kor , Aulesa Carlos , Piras Giampiero 
Published: January 2020

Abstract
We describe a multinational evaluation of the Menarini– Arkray HA 8140 hemoglobin (Hb) A1canalyzer, which utilizes a high degree of automation, including bar code reading, cap piercing, and whole-blood sampling. Within- and between-batch CVs were &lt;2%. Linearity was confirmed throughout the working range of the analyzer. Common Hb variants, including Hb S, Hb C, and Hb F, did not interfere with the Hb A1c separation, and the potentially interfering labile Schiff base was effectively removed during the chromatographic procedure. The HA 8140 analyzer displayed good correlation to the Bio-Rad Variant analyzer, Tinaquant immunoassay, affinity chromatography, and an optimized “in-house” HPLC Hb A1c method. The methods when compared by Altman and Bland plots showed bias (upper, lower 95% confidence limits) of: Variant minus HA 8140 = 0.99 (0.23, 1.74), Tinaquant minus HA 8140 = 0.14 (−0.71, 0.98); affinity minus HA 8140 (after log transformation) = 1.13 (0.90, 1.41), and “in house” HPLC minus HA 8140 (after log transformation) = 0.91 (0.82, 1.01).
Direct colorimetric monoclonal antibody enzyme immunoassay for estradiol-17β in saliva
Authors: Tamate Kenichi , Charleton Margaret , Gosling James P , Egan Declan , Ishikawa Mutsuo , Fottrell Patrick F , Kane Marian M 
Published: January 2020

AbstractWe developed a direct microtiter plate enzyme immunoassay to measure estradiol-17β in saliva. The assay has a commercially available monoclonal antibody, raised against estradiol-17β–6-carboxymethyloxime–bovine serum albumin, and a homologous horseradish peroxidase conjugate measured colorimetrically. The detection limit (equivalent to B0 − 3 SD) is 365 amol/well or 7.3 pmol/L when 50-μL samples are assayed. Cross-reactivity with estrone and estriol, testosterone, or progesterone is &lt;0.2%. Estradiol-17β was measured in daily samples over five natural menstrual cycles and eight cycles stimulated as a preliminary to in vitro fertilization, and the concentrations and fluctuations found agreed with previously published data. This method gives results in ∼3 h and may be useful for fertility monitoring and management.