bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endothelium and acute coronary syndromes
Authors: Liao James K 
Published: January 2020

AbstractThe vascular endothelium is a dynamic endocrine organ that regulates contractile, secretory, and mitogenic activities in the vessel wall and hemostatic processes within the vascular lumen. Risk factors for atherosclerosis such as cigarette smoking, hypertension, and increased serum lipid concentrations impair endothelial function and lead to the development of atherosclerotic vessels, which cause acute coronary syndromes. Atherosclerotic vessels progress from scattered foam cells to complex lesions with a lipid core and fibrous cap. Factors that weaken and cause the rupture of the fibrous cap will expose circulating blood products to the procoagulant materials in the lipid core. Thrombosis and subsequent remodeling of the unstable plaque may be catastrophic or clinically silent depending on the degree of vascular occlusion and availability of collateral blood flow. Evidence is presented that supports the view that endothelial dysfunction is an early marker of atherosclerosis and an important contributor to the atherogenic process.
Cardiac marker point-of-care testing in the Emergency Department and Cardiac Care Unit
Authors: Brogan Gerard X , Bock Jay L 
Published: January 2020

Abstract
There has been much interest in improving the accuracy and speed with which chest pain patients presenting to the emergency department are diagnosed and treated. Recently, attention has been directed toward alternative site or point-of-care testing for biochemical markers of myocardial cell necrosis in addition to traditional diagnostic methodologies. The various point-of-care cardiac marker devices available and their potential applications are discussed. Regulatory and quality management issues related of point-of-care testing are reviewed.
Different intracellular compartmentations of cardiac troponins and myosin heavy chains: a causal connection to their different early release after myocardial damage
Authors: Bleier Jürgen , Vorderwinkler Karl-Paul , Falkensammer Jürgen , Mair Peter , Dapunt Otto , Puschendorf Bernd , Mair Johannes 
Published: January 2020

AbstractWe investigated the net myocardial release of creatine kinase isoenzyme MB (CKMB), myoglobin, cardiac troponin T (cTnT), cardiac troponin I (cTnI), and cardiac β-type myosin heavy chain (β-MHC) into the coronary circulation after cardioplegic cardiac arrest in humans. Cardiac markers were measured in paired arterial, central venous, and coronary sinus blood in 19 patients undergoing elective coronary artery bypass grafting (CABG) before aortic cross-clamping and 1, 5, 10, and 20 min after aortic declamping. cTnT and cTnI were released into the coronary sinus in parallel to each other and almost simultaneously to myoglobin and CKMB within 20 min of reperfusion. In contrast, no β-MHC was released in the same patients during the study period. The average soluble cTnT and cTnI pools in right atrial appendages of 11 patients with right atrial and right ventricular pressures within reference values were comparable and were ∼8% of total myocardial troponin content. The soluble β-MHC pool was &lt;0.1% in all patients. Our results demonstrate the impact of the different intracellular compartmention of regulatory and contractile proteins on their early release from damaged myocardium.
Measurement of specific immunoglobulin E: intermethod comparison and standardization
Authors: Plebani Mario , Bernardi Daniela , Basso Daniela , Borghesan Franco , Faggian Diego 
Published: January 2020

Abstract
Recently introduced “second-generation” techniques for specific IgE measurement have produced some analytical improvement, offering better clinical sensitivity than previous techniques. The aims of our study were to compare the analytical and clinical performances of four second-generation techniques for allergen-specific IgE measurement in serum and to ascertain whether the new system for reporting quantitative results contributes to greater clinical agreement between findings using the techniques considered. Allergen-specific IgE was measured using the CAP® System, CARLA®, ENEA®, and AlaSTAT®, and the findings were compared. A significant disagreement was found between CAP and ENEA for all allergens and between CAP and CARLA for D1 and G5. However, the clinical discrepancies were reduced by selecting method-specific thresholds using ROC analysis. Second-generation techniques enable us to obtain better standardization of results; however, the identification of a specific threshold appears to be a prerequisite for the appropriate clinical interpretation of the test findings.
Thermal Instability of the Trimeric Structure of the N-terminal Propeptide of Human Procollagen Type I in Relation to Assay Technology
Authors: Brandt Jette , Krogh Thomas N , Jensen Charlotte H , Frederiksen Jette K , Teisner Børge 
Published: January 2020

Abstract
The N-terminal propeptide of procollagen type I (PINP) appeared in two peaks after size chromatography. The high-molecular weight form was transformed to the low-molecular weight form during incubation at 37 °C, whereas the low-molecular weight form remained unchanged. The PINP concentrations in amniotic fluid and sera remained unchanged during 37 °C incubation when measured using an ELISA; however, concentrations decreased by 89–93% when measured using an RIA. The ELISA:RIA ratio varied from 1.1 to 2.9 in these fluids because of different size distributions and the inability of the RIA to measure the low-molecular weight form. Thermal transition of the high-molecular weight form caused a change in its elution volume but did not change its migration in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mass spectrometry revealed identical results for both forms. We reached the following conclusions: (a) the trimeric structure of PINP is unstable at 37 °C; (b) the two molecular forms represent intact α1 chains in trimeric and monomeric forms; (c) thermal transition is an ongoing in vivo process; and (d) this is important in the choice of assay technology.
Whole Blood Capcellia CD4/CD8 Immunoassay for Enumeration of CD4+ and CD8+ Peripheral T Lymphocytes
Authors: Carrière Dominique , Vendrell Jean Pierre , Fontaine Claude , Jansen Aline , Reynes Jacques , Pagès Isabelle , Holzmann Catherine , Laprade Michel , Pau Bernard 
Published: January 2020

Abstract
We evaluated the Whole Blood Capcellia® CD4/CD8, an immunoenzymatic method that provides absolute counts of CD4+ and CD8+ T cells in peripheral blood. The assay is based on the separation of T cells by use of an anti-CD2 magnetic bead suspension, followed by reaction of the CD4 or CD8 molecules with the corresponding monoclonal antibody coupled to peroxidase. CD4-positive monocytes were excluded from the assay. Freeze-dried magnetic bead-T-cell complexes were used as calibrators. Capcellia counts from HIV-1-infected patients were compared with those obtained by flow cytometry as the comparison method. The results by Capcellia correlated well with those by flow cytometric analysis: r2 = 0.95; P &lt;0.001; (y = 0.96x − 22.1); Sy|x = 64 for CD4; r2 = 0.81; P &lt;0.001; (y = 1.26x − 76.4); Sy|x = 139 for CD8; n = 76. The correlation between CD4+ T-cell counts determined by two trained experimenters was significant (r2 = 0.96). Our results indicate that this new ELISA technique for lymphocyte immunophenotyping is an efficient alternative to flow cytometry.
Sensitive Assay for Mitochondrial DNA Polymerase γ
Authors: Naviaux Robert K , Markusic David , Barshop Bruce A , Nyhan William L , Haas Richard H 
Published: January 2020

AbstractBackground: The mitochondrial DNA polymerase γ is the principal polymerase required for mitochondrial DNA replication. Primary or secondary deficiencies in the activity of DNA polymerase γ may lead to mitochondrial DNA depletion. We describe a sensitive and robust clinical assay for this enzyme.Methods: The assay was performed on mitochondria isolated from skeletal muscle biopsies. High-molecular weight polynucleotide reaction products were captured on ion-exchange paper, examined qualitatively by autoradiography, and quantified by scintillation counting.Results: Kinetic analysis of DNA polymerase γ by this method showed a Km for dTTP of 1.43 μmol/L and a Ki for azidothymidine triphosphate of 0.861 μmol/L. The assay was linear from 0.1 to 2 μg of mitochondrial protein. The detection limit was 30 units (30 fmol dTMP incorporated in 30 min). The linear dynamic range was three orders of magnitude; 30–30 000 units. Imprecision (CV) was 6.4% within day and 12% between days. Application of this assay to a mixed population of 38 patients referred for evaluation of mitochondrial disease revealed a distribution with a range of 0–2506 U/μg, reflecting extensive biologic variation among patients with neuromuscular disease.Conclusion: This assay provides a useful adjunct to current laboratory methods for the evaluation of patients with suspected mitochondrial DNA depletion syndromes.
Human Glandular Kallikrein in Breast Milk, Amniotic Fluid, and Breast Cyst Fluid
Authors: Magklara Angeliki , Scorilas Andreas , López-Otín Carlos , Vizoso Francisco , Ruibal Alvaro , Diamandis Eleftherios P 
Published: January 2020

Abstract
Background: Human glandular kallikrein (hK2) belongs to the serine protease family of enzymes and has high sequence homology with prostate-specific antigen (PSA). The physiological role of hK2 has not as yet been determined, but there is evidence that it can regulate the proteolytic activity of PSA through processing and activating pro-PSA, an inactive precursor. Thus, it is conceivable that these two secreted proteins may coexist in biological fluids. Currently, hK2 is considered an androgen-regulated and prostate-specific protein. Recently, it has been demonstrated that hK2 is expressed in the breast cancer cell line T-47D after stimulation by steroid hormones, and we reported that hK2 can be detected in a subset of breast tumor extracts. These data suggest that hK2 may be expressed in tissues other than the prostate, such as those in which PSA has already been detected. Because hK2 is a secreted protein, it may be present in various biological fluids.
Methods: We analyzed milk samples from lactating women, amniotic fluid from pregnant women, and breast cyst fluid from patients with gross breast cystic disease, using a highly sensitive and specific immunoassay for hK2.
Results: hK2 was present in all three biological fluids. We suggest that the female breast may produce hK2 and provide evidence that hK2 may have value as an additional marker for the discrimination between type I and type II breast cysts.
Conclusions: The female breast produces hK2 in addition to PSA. More studies are necessary to establish the role of this kallikrein in nondiseased breast, gross breast cystic disease, and breast cancer.
Overexpression of Erythrocyte Glutathione S-Transferase in Uremia and Dialysis
Authors: Galli Francesco , Rovidati Simona , Benedetti Serena , Buoncristiani Umberto , Covarelli Carla , Floridi Ardesio , Canestrari Franco 
Published: January 2020

AbstractBackground: Overexpression of glutathione S-transferase (GST; EC 2.5.1.18) has been documented in the erythrocytes of patients with chronic renal failure, and this event may well be of relevance from a clinical standpoint. In fact, it could serve as a marker of uremic toxicity overall, which can contribute to impair the function and survival of the erythrocytes. However, the biochemical details of this phenomenon are poorly understood.Methods: In this study, we characterized the expression of GST in erythrocytes of 118 uremic patients under different clinical conditions. The mechanisms responsible for the regulation of protein expression and enzyme activity were investigated in light of different dialysis approaches, oxidative stress, uremic toxins, erythrocyte age, and erythropoietin (EPO) supplementation.Results: Mean GST activity in uremic patients was highly overexpressed with respect to controls, and this phenomenon was exclusively attributable to an increased expression of GST. Overexpression of GST did not appear to be dependent on oxidative stress and was not influenced by vitamin E supplementation. In the same manner, both erythrocyte age and EPO supplementation apparently did not interfere with the GST concentrations, which were the same in controls and patients. Preliminary experiments suggested that high-molecular weight or protein-bound toxins could play some role in the overexpression of GST.Conclusions: GST expression may be a useful marker for the individual accumulation of uremic toxins as well as of the efficiency of new dialysis strategies in removing them.
Human Pharmacokinetics of l-3,4-Dihydroxyphenylalanine Studied with Microdialysis
Authors: Dizdar Nil , Kullman Anita , Norlander Björn , Olsson Jan-Edvin , Kågedal Bertil 
Published: January 2020

Abstract
Background: Intravenous and subcutaneous microdialysis was performed to compare the free concentrations and pharmacokinetics of l-3,4-dihyroxyphenylalanine (l-dopa) in blood and tissue in healthy subjects and in patients with Parkinson disease.
Methods: Nine healthy volunteers and 10 patients with Parkinson disease, stage 1.5–2 according to the Hoehn-Yahr rating scale, took part of the study. In the patient group subcutaneous microdialysis and ordinary blood sampling were performed, whereas in the control group intravenous microdialysis was also performed. Microdialysis samples were collected in fractions of 15 min. The first two fractions were collected for analysis of basal concentrations. A blood sample was also taken. The patients were then given one tablet of Madopar® (100 mg of l-dopa and 25 mg of benserazide), and the microdialysis was continued for another 210 min. Blood samples were obtained at 30-min intervals.
Results: The serum samples gave a significantly higher mean area under the curve (AUC; 491 ± 139 μmol · min/L) than that for intravenous dialysates (235 ± 55.3 μmol · min/L), suggesting a protein binding of 50%. The l-dopa concentrations from the subcutaneous dialysates matched those from the intravenous dialysates, indicating rapid distribution of l-dopa to the tissues.
Conclusions: Parkinsonian patients in early stages of the disease have a pharmacokinetic pattern of free l-dopa similar to that of healthy subjects. Comparison of AUCs from microdialysis with ordinary serum analysis revealed data indicating significant protein binding. Microdialysis is a suitable and easily applied tool in pharmacokinetic studies.
Multicenter Evaluation of Tosoh Glycohemoglobin Analyzer
Authors: Gibb Ian , Parnham Angela , Fonfrède Michele , Lecock Freddy 
Published: January 2020

Abstract
Background: We describe an Anglo-French evaluation of a new analyzer.
Methods: The Tosoh HLC-723 GHb V, A1c2.2 glycohemoglobin analyzer is an HPLC instrument with primary blood tube sampling, bar-code reading, cap piercing, and the ability to chromatographically separate labile hemoglobin A1c (HbA1c). We evaluated two analytical protocols, 2.2 and 3.0 min, and compared results for blood samples collected from diabetic and nondiabetic subjects with those obtained with Bio-Rad Diamat and Variant analyzers.
Results: Within- and between batch-imprecision (CVs) was &lt;2% with linearity to at least 15.9% HbA1c. Although some hemoglobinopathies were detected in the 2.2-min chromatography, clearer evidence of abnormality was visible in the 3.0-min version. Comparison with established methods showed good correlation (r = 0.993; n = 316 with Diamat; and r = 0.995; n = 133 with Variant) but highlighted calibration differences.
Conclusions: The problems of manual blood sample preparation, labile HbA1c, and carbamylated hemoglobin interference associated with the older instruments have been eliminated in the new Tosoh analyzer. The 3.0-min protocol is preferred for routine use.
Different Real-Time PCR Formats Compared for the Quantitative Detection of Human Cytomegalovirus DNA
Authors: Nitsche Andreas , Steuer Nina , Schmidt Christian Andreas , Landt Olfert , Siegert Wolfgang 
Published: January 2020

Abstract
Background: The aim of this study was to compare the ABI PRISM 7700 Sequence Detection System and the LightCycler to develop a quantitative real-time PCR assay for the detection of human cytomegalovirus (HCMV) DNA suitable for routine hospital application.
Methods: We used one exonuclease probe and five different hybridization probe sets as sequence-specific fluorescence detection formats. For the exonuclease assay and two hybridization probe sets, reproducibility and the detection limit were determined. To keep the total assay time to a minimum, we gradually shortened individual reaction steps on both instruments.
Results: The exonuclease assay can be interchangeably performed on the 7700 and the LightCycler. No change of reaction conditions is required, except for the addition of bovine serum albumin to the LightCycler reaction. The shortest possible total assay time is 80 min for the ABI PRISM 7700 Sequence Detection System and 20 min for the LightCycler. When the LightCycler is used, the exonuclease probe can be replaced by a set of hybridization probes. All assays presented here detected HCMV DNA in a linear range from 101 to 107 HCMV genome equivalents/assay (r &gt;0.995) with low intraassay (&lt;5%) and interassay (&lt;10%) variation.
Conclusions: The ABI PRISM 7700 Sequence Detection System as well as the LightCycler are useful instruments for rapid and precise online PCR detection. Moreover, the two principles of fluorescence signal production allow HCMV quantification with the same accuracy.
Two-Site Expression Immunoassay Using a Firefly Luciferase-coding DNA Label
Authors: Chiu Norman HL , Christopoulos Theodore K 
Published: January 2020

AbstractBackground: We report the first two-site, “sandwich type” expression immunoassay using as a label an expressible DNA fragment encoding firefly luciferase.Methods: The DNA label consisted of a T7 RNA polymerase promoter, a firefly luciferase-coding sequence, and a poly(dA/dT) tail. The 3′ end of the DNA label was biotinylated and complexed with streptavidin. A sandwich immunoassay for prostate-specific antigen (PSA) was developed in which the antigen was first bound to an immobilized monoclonal antibody and then reacted with a biotinylated polyclonal antibody. The streptavidin-luciferase-coding DNA complex was then bound to the immunocomplex. The DNA label was subsequently expressed in vitro by coupled transcription and translation. The generated luciferase was measured by its characteristic bioluminescent reaction.Results: The bioluminescence was linearly related to the concentration of PSA in the sample. As low as 30 ng/L PSA was measured (12.5-μL sample) with a signal-to-background ratio of 2.3, and the linear range extended to 3 μg/L. The results obtained from the proposed assay agreed well to those determined by IMx immunoassay (y = 0.98x + 0.74 μg/L; r = 0.971; n = 44).Conclusions: The use of the newly developed DNA label in a two-site immunoassay was demonstrated for the first time. The assay was applied successfully to the measurement of serum PSA.
Endpoint Colorimetric Method for Assaying Total Cholesterol in Serum with Cholesterol Dehydrogenase
Authors: Kayamori Yuzo , Hatsuyama Hiroyuki , Tsujioka Tadayoshi , Nasu Masato , Katayama Yoshiaki 
Published: January 2020

AbstractBackground: Various methods are available to measure serum cholesterol concentrations. Of these, the cholesterol ester hydrolase (CEH)-cholesterol oxidase-peroxidase chromogenic method is widely used. However, this method has the disadvantage of interference by reducing substances. We developed and evaluated an endpoint assay for serum cholesterol, based on a CEH-cholesterol dehydrogenase (CDH)-ultraviolet method.Methods: Cholesterol esters are first hydrolyzed to free cholesterol by CEH. The free cholesterol is then reduced by CDH to cholest-4-ene-3-one with the simultaneous production of β-NADH from β-NAD+. At equilibrium, the CDH reaction gives incomplete conversion of cholesterol to cholest-4-ene-3-one. To overcome this disadvantage, we added hydrazine monohydrate to the reaction mixture to remove cholest-4-ene-3-one, which allowed the reaction to proceed to completion and gave stoichiometric production of β-NADH from the reaction of β-NAD+ with cholesterol.Results: We tested whether the amount of cholesterol added was equivalent to the absorbance change of NADH at 340 nm with six aqueous samples. Recoveries were 97.1–100.3%. The reaction was linear up to 20.28 mmol/L. The mean within-day (n = 20) and between-day (n = 10) imprecision (CV) was 0.29–0.43% and 0.22–0.61%, respectively. No interference by bilirubin, hemoglobin, ascorbic acid, and other reducing agents was observed. The equation obtained in comparison with the modified Abell-Levy-Brodie-Kendall method was: y = 0.992x − 0.0058 mmol/L; r = 0.997; Sy|x = 0.117 mmol/L; n = 50.Conclusion: This method is an accurate, reliable method for serum cholesterol analysis and is amenable to automation.
Preanalytical Variables Affecting the Quantification of Fatty Acid Ethyl Esters in Plasma and Serum Samples
Authors: Soderberg Britt L , Sicinska Ewa T , Blodget Emily , Cluette-Brown Joanne E , Suter Paolo M , Schuppisser Theresa , Vetter Wilhem , Laposata Michael 
Published: January 2020

AbstractBackground: Fatty acid ethyl esters (FAEEs) are cytotoxic nonoxidative ethanol metabolites produced by esterification of fatty acids and ethanol. FAEEs are detectable in blood up to 24 h after ethanol consumption. The objective of this study was to assess the impact of gender, serum or plasma triglyceride concentration, time and temperature of specimen storage, type of alcoholic beverage ingested, and the rate of ethanol consumption on FAEE concentrations in plasma or serum.Methods: For some studies, subject were recruited volunteers; in others, residual blood samples after ethanol quantification were used. FAEEs were isolated by solid-phase extraction and quantified by gas chromatography–mass spectrometry.Results: For weight-adjusted amounts of ethanol intake, FAEE concentrations were twofold greater for men than women (P ≤0.05). Accounting for triglycerides improved the correlation between blood ethanol concentrations and FAEE concentrations for both men (from r = 0.640 to r = 0.874) and women (from r = 0.619 to r = 0.673). FAEE concentrations did not change when samples were stored at or below 4 °C, but doubled when stored at room temperature for ≥24 h. The type of alcoholic beverage and rate of consumption did not affect FAEE concentrations.Conclusion: These studies advance plasma and serum FAEE measurements closer to implementation as a clinical test for ethanol intake.
Arsenic Speciation in Human Organs following Fatal Arsenic Trioxide Poisoning—A Case Report
Authors: Benramdane Larbi , Accominotti Michele , Fanton Laurent , Malicier Daniel , Vallon Jean-Jacques 
Published: January 2020

AbstractThe aim of this investigation was to study the distribution of arsenic species in human organs following fatal acute intoxication by arsenic trioxide. The collected autopsy samples of most organs were ground and dried, and the total arsenic was measured by electrothermal atomic absorption spectrometry (ETAAS). The arsenic species—inorganic arsenic, in the form of arsenite [As(III)] and arsenate [As(V)], and its metabolites [monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)]—were quantified by ETAAS after extraction with methanol/water (1:1, by volume) and separation by HPLC. The results indicate that after acute intoxication, the liver and kidneys show the highest concentrations of total arsenic and that the total concentration in blood is 7- to 350-fold less concentrated than in organs. In all organs, As(III) is the predominant species, and MMA is more concentrated than DMA. MMA and DMA are more prevalent in lipidic organs (49% of total arsenic) compared with other organs (25% of total arsenic). As(V) was found in small quantities in the liver, kidneys, and blood.