bluuebunny/crossref_metadata_2025_split huggingface dataset:
Apolipoprotein B and A-I values in 147 576 Swedish males and females, standardized according to the World Health Organization–International Federation of Clinical Chemistry First International Reference Materials
Authors: Jungner Ingmar , Marcovina Santica M , Walldius Göran , Holme Ingar , Kolar Werner , Steiner Eugen 
Published: January 2020

Abstract
Serum concentrations of apolipoprotein (apo) B and apo A-I were measured from 1985–1996 in a Swedish population sample of 83 112 males and 64 464 females, ages &lt;20 to &gt;80 years, using an automated immunoturbidimetric method calibrated against fresh pools of human serum and commercial calibrators. All values were recalculated in 1997 after calibration against the WHO-IFCC First International Reference Materials. The recalculation factor was 1.059 for apo B, whereas for apo A-I, the correction was: y = 0.989x + 0.101. The total CVs for both apo B and A-I were generally &lt;7%. The mean value (± SD) for apo B was 1.31 ± 0.35 g/L in all males and 1.22 ± 0.36 g/L in all females. The mean apo A-I concentration was 1.36 ± 0.22 g/L in males–10% lower than in females (1.51 ± 0.24 g/L). The mean value of apo B increased up to 60 years of age in males and up to 70 years of age in females. apo A-I concentrations changed only slightly with age in both males and females. apo A-I concentrations among Swedes are nearly identical to those reported recently by two American studies and those obtained in a Finnish population sample. Mean apo B concentrations differ somewhat between the populations but mirror–as expected–differences in total cholesterol concentrations. The highest values were noted in Swedish subjects. The Swedish sample population is, to our knowledge, the largest describing the distribution of apo B and A-I in a general population of adult males and females of all ages determined with procedures standardized and traceable to the WHO-IFCC First International Reference Materials.
Simultaneous HPLC determination with light-scattering detection of lactulose and mannitol in studies of intestinal permeability in pediatrics
Authors: Marsilio Renzo , D’Antiga Lorenzo , Zancan Lucia , Dussini Noemi , Zacchello Franco 
Published: January 2020

Abstract
We describe a new HPLC method for the simultaneous determination of lactulose and mannitol in urine, in which cation-exchange chromatography and evaporative light-scattering detection are used. The two sugars are orally administered for the estimation of intestinal permeability in children. Samples were purified by solid phase extraction on a C18 cartridge and subsequent addition of anion-exchange resin. Cellobiose may be used as an internal standard. The chromatographic separation was carried out in 16 min at a flow rate of 0.5 mL/min, using deionized water as the mobile phase. Within-run precision (CV) measured at three concentrations was 1.6–2.3% for lactulose and 1.0–1.9% for mannitol. Between-run CVs were 2.1–4.1% and 1.3–2.7% for lactulose and mannitol, respectively. Analytical recovery of both sugar probes was 97–101%. The detection limits (signal-to-noise ratio = 3) were 0.82 mg/L for lactulose and 0.65 mg/L for mannitol. The lactulose/mannitol ratio in control subjects was 0.024 ± 0.006; in patients with Crohn’s and coeliac diseases in active phase, the ratios were 0.200 ± 0.082 and 0.072 ± 0.025, respectively. The method is rapid, simple, and sensitive, and suitable for determination of intestinal permeability in children.
Obesity and cardiovascular disease
Authors: Sowers James R 
Published: January 2020

AbstractObesity, diabetes mellitus, and hypertension are common, interrelated medical problems in Westernized, industrialized societies. These interrelated medical conditions are associated with an increased risk of cardiovascular disease and are more prevalent in several minority groups, including African-American and Hispanic populations. The associated cardiovascular risks of these problems are more thoroughly addressed in another review in this supplement. Obesity markedly enhances the development of Type 2 diabetes. Moreover, it enhances the cardiovascular risk associated with other risk factors, such as hypertension and dyslipidemia. Weight reduction in association with an aerobic exercise program improves metabolic abnormalities and reduces blood pressure in individuals with diabetes and hypertension.
Evolving lipoprotein risk factors: lipoprotein(a) and oxidized low-density lipoprotein
Authors: Jialal Ishwarlal 
Published: January 2020

Abstract
Cardiovascular disease is the leading cause of morbidity and mortality in Westernized populations. Evolving lipoprotein risk factors include LDL oxidation and lipoprotein(a) [lp(a)]. Several lines of evidence support a role for oxidatively modified LDL in atherogenesis and its in vivo existence. There are both direct and indirect measures of oxidative stress. The most relevant direct measure of lipid peroxidation is urinary F2 isoprostanes. The most common indirect measure of LDL oxidation is quantifying the lag phase of copper-catalyzed LDL oxidation by assaying conjugated diene formation. Lp(a) is increased in patients with cardiovascular and cerebrovascular disease. However, not all prospective studies have confirmed a positive relationship between Lp(a) and cardiovascular events. Lp(a) appears to present three major problems: standardization of the assay, establishing its role in atherogenesis, and the lack of an effective therapy that can substantially lower Lp(a) concentrations. Thus, at the present time, Lp(a) concentrations should not be recommended for the general population but be reserved for patients with coronary artery disease without established risk factors, young patients with coronary artery disease or cerebrovascular disease, or a family history of premature atherosclerosis and family members of an index patient with increased concentrations of Lp(a). Although both LDL oxidation and Lp(a) are evolving risk factors for cardiovascular disease, more data are needed before they become part of the established lipoprotein repertoire.
5-Aminolevulinic acid dehydratase deficiency porphyria: a twenty-year clinical and biochemical follow-up
Authors: Gross Ulrich , Sassa Shigeru , Jacob Karl , Deybach Jean-Charles , Nordmann Yves , Frank Margareta , Doss Manfred O 
Published: January 2020

Abstract5-Aminolevulinic acid dehydratase (ALAD) activity in two patients with compound heterozygous 5-aminolevulinic acid dehydratase deficiency porphyria was studied over the last 20 years. The patients’ enzyme activity was &lt;10% from 1977 to 1997. An acute crisis in each patient was successfully treated by infusion of glucose and heme arginate. After this therapy both urinary 5-aminolevulinic acid (ALA) and total porphyrins were diminished to 65% in patient B. In patient H, ALA was decreased to 80%, and total porphyrins were reduced to 15% after treatment with heme arginate and glucose. The patients remained free of symptoms after this therapy. Family studies of patient B showed cross-reactive immunological material (CRIM), in which the maternal mutation is CRIM(+), whereas the paternal mutation is CRIM(−). Incubation of erythrocyte lysates with ALA decreased porphyrin formation, whereas incubation with porphobilinogen produced porphyrin concentrations within reference values in both patients, confirming that ALAD activity is rate-limiting in these cells.
Capillary electrophoresis for rapid profiling of organic acidurias
Authors: García Antonia , Barbas Coral , Aguilar Rosa , Castro Mario 
Published: January 2020

AbstractOrganic acids analysis is a powerful technique in the diagnosis of inborn errors of metabolism. Clinically, patients present with severe symptoms, and early detection and appropriate treatment are often lifesaving. Most of the existing methods are based on gas chromatography in combination with mass spectrometry and require sophisticated equipment and complex sample pretreatment and derivatization. We propose a rapid, simple, and automated capillary electrophoretic method for routine analysis of urine to detect 27 organic acids related to metabolic diseases. With this method, direct measurements are performed on samples after initial centrifugation and dilution, if needed. Separation is performed in pH 6.0 phosphate buffer with methanol added as an organic modifier, −10 kV applied potential, and ultraviolet detection at 200 nm. The assay is completed in &lt;15 min, and alternative separation conditions are proposed in case of overlapping peaks. The developed method allows the identification and quantitation of methylmalonic, pyroglutamic, and glutaric acids in samples of patients with diseases related to these acids.
Analytical performance and clinical application of a new rapid bedside assay for the detection of serum cardiac troponin I
Authors: Heeschen Christopher , Goldmann Britta U , Moeller Robert H , Hamm Christian W 
Published: January 2020

Abstract
Detection of cardiac troponin I (cTnI) in patients suspected of having an acute coronary syndrome is highly predictive for an adverse outcome. We evaluated a bedside test for cTnI that uses a polyclonal capture antibody and two monoclonal indicator antibodies. Clinical studies were performed in patients with acute coronary syndrome and patients with chest pain but no evidence of acute myocardial injury. The whole-blood, 15-minute assay had a concordance of 98.9% with an ELISA for cTnI and a detection limit of 0.14 μg/L, and the device tolerated temperatures between 4 °C and 37 °C. Diagnostic sensitivity for myocardial infarction at arrival (3.5 ± 2.7 h after onset of symptoms) was 60% [creatine kinase isoenzyme MB (CK-MB) mass, 48%; CK activity, 36%; P &lt; 0.01], and 4 h later, diagnostic sensitivity was 98% (CK-MB mass, 91%; CK activity, 61%; P &lt; 0.01). In 38% of the patients with unstable angina, at least one positive cTnI test was found (CK-MB mass, 4%; CK activity, 2%). No false-positive test results were found in renal failure or injury of skeletal muscle. We conclude that the diagnostic efficacy of the cTnI rapid test was comparable with the cTnI ELISA and superior to CK-MB determination. Therefore, this device could facilitate decision-making in patients with chest pain at the point of care.
False increase in C-reactive protein attributable to heterophilic antibodies in two renal transplant patients treated with rabbit antilymphocyte globulin
Authors: Benoist Jean-François , Orbach Daniel , Biou Daniel 
Published: January 2020

Abstract
Increased serum C-reactive protein (sCRP) is a sensitive marker of renal graft rejection. We describe the cases of two children with uncomplicated renal transplantation who had false-positive sCRP values on analyzers using rabbit anti-CRP but values within the reference range with anti-CRP from other animal species. Cross-reaction with heterophilic antibodies was suggested by clinical and biological signs of serum sickness and daily treatment with rabbit antilymphocyte globulin (ALG). The interference depended on the serum concentration of the cross-reactant and was removed by subtotal IgG adsorption to Protein A or Protein G or by immunoadsorption using rabbit ALG or total IgG in non-immune rabbit serum. Anti-rabbit IgG and IgM antibodies were detected in both patients. These are the first reported cases of cross-reaction with heterophilic antibodies in a turbidimetric CRP assay.
New Insights into the Role of Nuclear Factor-κB, a Ubiquitous Transcription Factor in the Initiation of Diseases
Authors: Chen Fei , Castranova Vince , Shi Xianglin , Demers Laurence M 
Published: January 2020

AbstractNuclear factor-κB (NF-κB) is a ubiquitous transcription factor that governs the expression of genes encoding cytokines, chemokines, growth factors, cell adhesion molecules, and some acute phase proteins in health and in various disease states. NF-κB is activated by several agents, including cytokines, oxidant free radicals, inhaled particles, ultraviolet irradiation, and bacterial or viral products. Inappropriate activation of NF-κB has been linked to inflammatory events associated with autoimmune arthritis, asthma, septic shock, lung fibrosis, glomerulonephritis, atherosclerosis, and AIDS. In contrast, complete and persistent inhibition of NF-κB has been linked directly to apoptosis, inappropriate immune cell development, and delayed cell growth. Therefore, development of modulatory strategies targeting this transcription factor may provide a novel therapeutic tool for the treatment or prevention of various diseases.
Improved Extraction Procedure and RIA for Determination of Arginine8-Vasopressin in Plasma: Role of Premeasurement Sample Treatment and Reference Values in Children
Authors: Kluge Michael , Riedl Stefan , Erhart-Hofmann Birgit , Hartmann Johannes , Waldhauser Franz 
Published: January 2020

Abstract
We optimized an RIA for measurement of arginine8-vasopressin (AVP) in plasma by use of 100-mg Isolute C18 columns for extraction, addition of a preincubation step, and use of maximal dilution of a commercially available antiserum. The detection limit was 0.06 ng/L when 0.5 mL of acidified plasma was extracted. The within- and between-run CVs (n = 16) at physiological concentrations were 5.8–10.2% and 6.5–11.7%, respectively. Prolonged storage of blood at 25 °C, but not at 4 °C, led to a significant increase in measured plasma AVP concentrations. When plasma samples were prepared at several centrifugation speeds, plasma AVP was significantly correlated with the platelet count (r = 0.899; P &lt;0.001). This emphasizes the need for careful sample preparation to avoid contamination of plasma with platelet-bound AVP. Basal plasma AVP in 203 children and adolescents (105 males and 98 females; ages, 1 day to 18 years) averaged 1.1 ± 0.6 ng/L. There was no significant difference between males and females and no correlation with age. In 16 healthy adult controls, plasma AVP averaged 1.0 ± 0.5 ng/L.
Simple, Rapid, Quantitative, and Sensitive Detection of Telomere Repeats in Cell Lysate by a Hybridization Protection Assay
Authors: Nakamura Yasuhiro , Hirose Minoru , Matsuo Hajime , Tsuyama Naohiro , Kamisango Keiichi , Ide Toshinori 
Published: January 2020

Abstract
Background: Detection of telomere repeats by Southern hybridization of genomic DNA is time consuming, and the reading of a mean terminal restriction fragment (TRF) length from a smear pattern of an autoradiogram can be inaccurate. We developed a hybridization protection assay (HPA) for telomere repeats.
Methods: We heated 5 μL of DNA solution or 10 μL of cell or tissue lysate at 95 °C for 5 min, mixed it with 100 μL of hybridization solution containing 3 × 106 relative light units of acridinium ester-labeled probe, and incubated the mixture for 20 min at 60 °C. We then added 300 μL of selection buffer and incubated the mixture for 10 min at 60 °C to differentially hydrolyze unhybridized probe. Chemiluminescence was measured for 2 s per tube.
Results: The amount of telomere repeats was assayed by HPA within linearity from 10 to 3000 ng of purified genomic DNA or from 1000 to 100 000 cell equivalents of lysate. To normalize the amount of DNA in lysate, the amount of Alu sequence was measured by HPA. A ratio of telomere to Alu (TA ratio) = 0.01 corresponded to ∼2 kbp of mean TRF length determined by Southern blotting in cultured fibroblast and colorectal tissue samples. The TA ratio decreased from 0.06 to 0.02 with increasing division age from 30 to 90 population doubling levels of cultured human fetal fibroblasts. The assay required ∼45 min from collection of cell or tissue samples.
Conclusions: The amount of telomere repeats was quantitatively measured by HPA in 10 ng of sheared genomic DNA or in the lysate of 1000 cells. This method is simple, rapid, quantitative, sensitive, and applicable to the measurement of telomere repeats in clinical samples such as needle biopsy specimen or as few as 1000 cells in body fluid or washings.
Time-resolved Immunofluorometric Assay of Trypsin-1 Complexed with α1-Antitrypsin in Serum: Increased Immunoreactivity in Patients with Biliary Tract Cancer
Authors: Hedström Johan , Haglund Caj , Kemppainen Esko , Leinimaa Maarit , Leinonen Jari , Stenman Ulf-Håkan 
Published: January 2020

AbstractBackground: Increased serum concentrations of trypsin immunoreactivity occur in patients with biliary tract cancer. To characterize this trypsin, we developed a sensitive time-resolved immunofluorometric assay for trypsin-1 complexed with α1-antitrypsin (AAT) and studied the concentrations of this complex in sera from healthy individuals (n = 130) and patients with benign biliary disease (n = 32), biliary tract cancer (n = 17), pancreatic cancer (n = 27), and hepatocellular cancer (n = 12).Methods: We used a trypsin-1-specific monoclonal antibody on the solid phase and a europium-labeled polyclonal antibody to AAT as tracer. The detection limit was 0.42 μg/L. The validity of the trypsin-1-AAT test for detection of biliary tract cancer was compared with trypsin-2-AAT and CA19-9.Results: Increased concentrations of trypsin-1-AAT (&gt;33 μg/L) were found in 76% of patients with biliary tract cancer, and the concentrations were significantly higher than in those with benign biliary disease (P &lt;0.0001). The median concentration of trypsin-1-AAT in serum from patients with biliary tract cancer was 3.7-fold higher than in healthy controls, 2.6-fold higher than in patients with benign biliary tract disease, 1.7-fold higher than in patients with pancreatic cancer, and 2.0-fold higher than in patients with hepatocellular cancer.Conclusions: Of the markers studied, trypsin-1-AAT had the largest area (0.83) under the receiver operating curve in differentiating biliary tract cancer from benign biliary tract disease. Our results suggest that trypsin-1-AAT is a new potential marker for biliary tract cancer.
Within-Person Variation of Plasma Homocysteine and Effects of Posture and Tourniquet Application
Authors: Rasmussen Karsten , Møller Jan , Lyngbak Marianne 
Published: January 2020

Abstract
Background: Frequently, the result of only a single determination of total homocysteine in plasma (P-Hcy) is used to distinguish between the probability of the presence or absence of risk for vascular disease. A prerequisite for the interpretation of a single P-Hcy test is knowledge of the magnitude of within-person variation and the possible effects of preanalytical variables. However, data on within-person variation are still sparse and inconsistent, and data for the effect on P-Hcy of posture and tourniquet application during venipuncture are not available.
Methods: The within-person variation of P-Hcy and the effects of posture and tourniquet application during venipuncture were studied in 24 healthy subjects. The analytical imprecision of our stable-isotope dilution assay was 3.1%.
Results: The within-person variation (CV) was 8.1%. Daily supplementation with 0.4 mg of folic acid for 2 weeks produced a small but significant decrease in P-Hcy, but there were no significant changes in within-person variation before and after supplementation. After 30 min in the horizontal posture, P-Hcy declined by 6.3%. A 3-min tourniquet application caused a 2.8% increase of P-Hcy.
Conclusions: Our value for within-person variation is consistent with results from studies reported recently in the literature. A 3-min tourniquet application does not add appreciable variation to the measurement of P-Hcy, but the posture of the subject during venipuncture contributes considerably to the within-person variation. We recommend that blood collection when the patient is in a supine position be avoided.
Neopterin Is an Independent Prognostic Variable in Females with Breast Cancer
Authors: Murr Christian , Bergant Anton , Widschwendter Martin , Heim Kurt , Schröcksnadel Hans , Fuchs Dietmar 
Published: January 2020

AbstractBackground: Neopterin, produced by human monocytes/macrophages upon stimulation by interferon-γ, is a sensitive marker for monitoring Th1-cell immune response in humans. In malignant diseases, the frequency of increases in neopterin in the serum and urine of patients depends on tumor stage and type.Methods: In a retrospective study comprising 129 females with breast cancer, urinary neopterin/creatinine ratios were measured at the time of diagnosis. Tumor characteristics were determined concomitantly.Results: Urinary neopterin was increased in 18% of the patients. It did not correlate with tumor size or lymph node status, but it was influenced by the presence of distant metastases (P &lt;0.05) and by tumor differentiation (P = 0.01). When product-limit estimates were calculated after follow-up for up to 13 years (median follow-up, 56 months), the presence of distant metastases (P &lt;0.001), neopterin (P &lt;0.001), tumor size (P = 0.001), and lymph node status (P &lt;0.01) were significant predictors of survival. By multivariate analysis, a combination of the variables presence of distant metastases (P &lt;0.001), neopterin (P &lt;0.01), and lymph node status (P &lt;0.05) was found to jointly predict survival. In lymph node-negative patients without distant metastases, the relative risk of death associated with increased neopterin concentrations was 2.5 compared with patients with neopterin concentrations within the reference interval.Conclusion: Urinary neopterin provides additional prognostic information in patients with breast cancer.
Clinical Efficacy of an Automated High-Sensitivity C-Reactive Protein Assay
Authors: Rifai Nader , Tracy Russell P , Ridker Paul M 
Published: January 2020

Abstract
Background: Prospective studies have shown that C-reactive protein (CRP) can be used to predict risk of future cardiovascular events. High-sensitivity methods for CRP (hs-CRP) measurement are needed for this purpose.
Methods: We compared the clinical efficacy of an automated and commercially available latex-enhanced assay (Latex) for hs-CRP (Dade Behring) to a validated in-house ELISA, previously shown to predict future peripheral arterial disease (PAD) in asymptomatic populations. Using a prospective, nested, case-control design, we measured baseline hs-CRP concentrations in 144 apparently healthy men who subsequently developed symptomatic PAD and 144 age- and smoking habit-matched controls who remained free of vascular disease over the follow-up period of 60 months.
Results: The two hs-CRP assays correlated highly (r = 0.95; P &lt;0.001), and all but two participants were classified into concordant quartiles or varied by only one quartile. The median hs-CRP of the case group was significantly higher than that of controls when measured by either the ELISA (1.34 vs 0.99 mg/L; P = 0.034) or the Latex method (1.80 vs 1.20 mg/L; P = 0.042). Furthermore, for both ELISA and the Latex method, the calculated relative risks of developing PAD increased significantly with each increasing quartile of hs-CRP. The calculated interquartile increase in relative risk of PAD was 31% (95% confidence interval, 5.2–62.2%; P = 0.01) for ELISA and 34% (95% confidence interval, 8.2–66.1%; P = 0.007) for the Latex method.
Conclusions: Our findings indicate that the Latex method is equally as efficacious as the validated ELISA in classifying patients into cutoff points established by prospective studies for risk stratification for coronary and cerebrovascular disease.