bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased Glutathionyl Hemoglobin in Diabetes Mellitus and Hyperlipidemia Demonstrated by Liquid Chromatography/Electrospray Ionization-Mass Spectrometry
Authors: Niwa Toshimitsu , Naito Chika , Mawjood Abdul Hassan Mohammed , Imai Kiyohiro 
Published: January 2020

AbstractBackground: Erythrocytes contain a large amount of glutathione (GSH), which protects cells from oxidative injury. The purpose of this study was to examine whether hemoglobin (Hb) is modified with glutathione by oxidation of the thiol groups in diabetes mellitus and hyperlipidemia, and to determine the oxygen affinity of glutathionyl Hb.Methods: Hb samples obtained from patients with type 2 diabetes, patients with hyperlipidemia, and healthy subjects were analyzed by liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS). Glutathionyl Hb was synthesized in vitro by incubating Hb with GSH. The oxygen affinity of glutathionyl Hb was determined by measuring its oxygen dissociation curve.Results: We first demonstrated that the concentration of glutathionyl Hbβ chains is markedly increased in the diabetic patients and hyperlipidemic patients compared with healthy subjects. The in vitro synthesis of glutathionyl Hb by incubation of Hb with GSH was enhanced by adding H2O2, a reactive oxygen species, into the incubation solution. The glutathionyl Hb prepared in vitro by incubating Hb with GSH showed a marked increase in oxygen affinity and a marked decrease in the Hill coefficient compared with Hb incubated without GSH.Conclusions: Glutathionyl Hb may be useful as a clinical marker of oxidative stress. The increased concentrations of glutathionyl Hb with high oxygen affinity and low cooperativity in diabetes and hyperlipidemia may lead to reduced tissue oxygen delivery.
Discriminating Capacity of Indole Markers in the Diagnosis of Carcinoid Tumors
Authors: Meijer Wim G , Kema Ido P , Volmer Marcel , Willemse Pax H B , de Vries Elisabeth G E 
Published: January 2020

Abstract
Background: We evaluated the discriminating capacity of the indole markers urinary 5-hydroxyindoleacetic acid (5-HIAA), urinary serotonin, and platelet serotonin in the diagnosis of carcinoid tumors.
Methods: Indole markers were measured in 688 patients with suspected carcinoid disease. The initial values of indole markers from patients in whom a carcinoid tumor was confirmed during follow-up (n = 98) were used for ROC analysis. Two groups served as reference populations. The first consisted of 45 healthy individuals (“healthy controls”). The second was a random sample of 40 patients, drawn from the 590 (688 minus 98) patients with carcinoid-like symptoms but without a carcinoid tumor (“clinically suspected patients”).
Results: ROC curve analysis showed platelet serotonin to have the highest discriminating capacity, especially in foregut carcinoids. Cutoff values for platelet serotonin obtained from ROC analysis with healthy controls as reference group (5.4 nmol/109 platelets) gave a sensitivity of 74%, specificity of 91%, positive predictive value of 63%, and negative predictive value of 95% when applied to the initial 688 patients. Using the cutoff value with the clinically suspected patients as the reference group (9.3 nmol/109 platelets) gave a sensitivity of 63%, specificity of 99%, positive predictive value of 89%, and negative predictive value of 93%. Indole markers were increased in 169 (25%) of 688 patients. In 76 (45%) of these 169 patients, a carcinoid tumor was present. Slight increases of markers were associated with non-carcinoid neuroendocrine tumors, non-neuroendocrine tumors, and disturbed bowel motility.
Conclusions: ROC curve analysis shows that platelet serotonin is the most discriminating indole marker for the diagnosis of carcinoid tumors. Platelet serotonin especially improves the diagnosis of carcinoids producing small amounts of serotonin.
C-Reactive Protein and Cardiac Troponin T in Risk Stratification: Differences in Optimal Timing of Tests Early after the Onset of Chest Pain
Authors: de Winter Robbert J , Fischer Johan , Bholasingh Radha , van Straalen Jan P , de Jong Thyra , Tijssen Jan G P , Sanders Gerard T 
Published: January 2020

AbstractBackground: Increased C-reactive protein (CRP) is an important prognostic indicator for early risk stratification in patients with an acute coronary syndrome (ACS), independent of, and in combination with, increased cardiac troponin T (cTnT). However, increases in both cTnT and CRP also occur secondary to myocardial damage.Methods and Results: In 156 consecutive patients, early release kinetics of CRP and cTnT were analyzed. The cutoff values were 3.0 mg/L for CRP and 0.1 μg/L for cTnT. In the 75 patients with a CRP below the cutoff on admission, there was little change in CRP until 8 h after the onset of symptoms. At 12 h after the onset of symptoms, the cumulative proportions of abnormal CRP and cTnT in non-ST elevation ACS patients were 27% and 89%, respectively (P &lt;0.01). During the first 24 h after the onset of symptoms, the median time above the cutoff was 20 h for CRP and 5 h for cTnT (P &lt;0.0001). CRP was below the cutoff on admission significantly more often among patients receiving thrombolytic therapy than in patients without an indication for reperfusion therapy (51% vs 28%; P = 0.004).Conclusions: Increased CRP as an early independent risk indicator should be measured as soon as possible after the onset of symptoms, whereas increased cTnT is most reliable at 12 or more hours after the onset of symptoms.
Clinical Evaluation of the First Medical Whole Blood, Point-of-Care Testing Device for Detection of Myocardial Infarction
Authors: Apple Fred S , Anderson F Philip , Collinson Paul , Jesse Robert L , Kontos Michael C , Levitt M Andrew , Miller Elizabeth A , Murakami MaryAnn M 
Published: January 2020

AbstractBackground: Validation of whole blood, point-of-care testing devices for monitoring cardiac markers to aid clinicians in ruling in and ruling out myocardial infarction (MI) is necessary for both laboratory and clinical acceptance.Methods: This study evaluated the clinical diagnostic sensitivity and specificity of the First Medical Cardiac Test device operated by nursing and laboratory personnel that simultaneously measures cardiac troponin I (cTnI), creatine kinase (CK) MB, myoglobin, and total CK on the Alpha Dx analyzer in whole blood for detection of MI. Over a 6-month period, 369 patients initially presenting to the emergency department with chest pain were evaluated for MI using modified WHO criteria. Eighty-nine patients (24%) were diagnosed with MI.Results: In whole blood samples collected at admission and at 3- to 6-h intervals over 24 h, ROC curve-determined MI decision limits were as follows: cTnI, 0.4 μg/L; CKMB, 7.0 μg/L; myoglobin, 180 μg/L; total CK, 190 μg/L. Based on peak concentrations within 24 h after presentation, the following sensitivities (± 95% confidence intervals) were found: cTnI, 93% ± 5.5%; myoglobin, 81% ± 9.7%; CKMB, 90% ± 6.3%; total CK, 86% ± 7.5%. Sensitivities were maximal at &gt;90% for both cTnI and CKMB at &gt;12 h in MI patients, without differences between ST-segment elevation and non-ST-segment elevation MI patients.Conclusions: The First Medical point-of-care device provides cardiac marker assays that can be used by laboratories and clinicians in a variety of hospital settings for ruling in and ruling out MI.
The Haptoglobin 2-2 Phenotype Affects Serum Markers of Iron Status in Healthy Males
Authors: Langlois Michel R , Martin Marie-Elise , Boelaert Johan R , Beaumont Carole , Taes Youri E , De Buyzere Marc L , Bernard Dirk R , Neels Hugo M , Delanghe Joris R 
Published: January 2020

AbstractBackground: Human iron status is influenced by environmental and genetic factors. We hypothesized that the genetic polymorphism of haptoglobin (Hp), a hemoglobin-binding plasma protein, could affect iron status.Methods: Reference values of serum iron status markers were compared according to Hp phenotypes (Hp 1-1, Hp 2-1, Hp 2-2; determined by starch gel electrophoresis) in 717 healthy adults. Iron storage was investigated in peripheral blood monocyte-macrophages by measuring cytosolic L- and H-ferritins and by in vitro uptake of radiolabeled (125I) hemoglobin-haptoglobin complexes.Results: In males but not in females, the Hp 2-2 phenotype was associated with higher serum iron (P &lt;0.05), transferrin saturation (P &lt;0.05), and ferritin (P &lt;0.01) concentrations than Hp 1-1 and 2-1, whereas soluble transferrin receptor concentrations were lower (P &lt;0.05). Moreover, serum ferritin correlated with monocyte L-ferritin content (r = 0.699), which was also highest in the male Hp 2-2 subgroup (P &lt;0.01). In vitro, monocyte-macrophages took up a small fraction of 125I-labeled hemoglobin complexed to Hp 2-2 but not to Hp 1-1 or 2-1.Conclusions: The Hp 2-2 phenotype affects serum iron status markers in healthy males and is associated with higher L-ferritin concentrations in monocyte-macrophages because of a yet undescribed iron delocalization pathway, selectively occurring in Hp 2-2 subjects.
Intraoperative Parathyroid Hormone Analysis: A Study of 200 Consecutive Cases
Authors: Sokoll Lori J , Drew Helen , Udelsman Robert 
Published: January 2020

Abstract
Background: Immunoassays for parathyroid hormone (PTH), with short incubation times and results available in &lt;15 min, have allowed intraoperative monitoring of the success of parathyroid surgery. The purpose of this study was to evaluate the analytical performance of a rapid PTH assay and its clinical performance in a series of 200 patients.
Methods: PTH was measured with a modified immunochemiluminometric assay with a 7-min incubation time (QuiCk-IntraOperative™ Intact PTH assay). The rapid assay was compared with results in a central laboratory (immunoradiometric assay) in 44 EDTA-plasma specimens. The rapid assay was used intraoperatively in 200 consecutive cases with specimens analyzed before and 5–10 min after resection of the hypersecreting parathyroid gland(s).
Results: Intraassay imprecision was 12% at 28 ng/L and 11% at 278 ng/L. Regression analysis of results of the rapid PTH assay and the IRMA PTH assay in 44 parathyroidectomy patients yielded y = 1.26x − 12 ng/L, Sy|x = 26.3 ng/L, r = 0.984, and in 40 of 44 patients with values &lt;200 ng/L, y = 1.02x + 1.9, Sy|x = 13.9, r = 0.947. In the 195 cases using intraoperative PTH testing with complete results and defined clinical outcomes, the overall accuracy of the assay in predicting surgical success was 88% using the criterion of a 50% decrease at 5–10 min and 97% including the subset of patients with delayed decreases of PTH.
Conclusions: The rapid PTH assay had excellent analytical performance and excellent agreement with the PTH immunoradiometric assay and predicted the success of parathyroid surgery in this large series of consecutive patients.
Rapid Screening Method for Osteoclast Differentiation in Vitro That Measures Tartrate-resistant Acid Phosphatase 5b Activity Secreted into the Culture Medium
Authors: Alatalo Sari L , Halleen Jussi M , Hentunen Teuvo A , Mönkkönen Jukka , Väänänen H Kalervo 
Published: January 2020

AbstractBackground: Osteoclasts secrete tartrate-resistant acid phosphatase (TRAP; EC 3.1.3.2) 5b into the circulation. We studied the release of TRAP 5b from osteoclasts using a mouse in vitro osteoclast differentiation assay.Methods: We developed and characterized a polyclonal antiserum in rabbits, using purified human osteoclastic TRAP 5b as antigen. The antiserum was specific for TRAP in Western analysis of mouse osteoclast culture medium and was used to develop an immunoassay. We cultured mouse bone marrow-derived osteoclast precursor cells for 3–7 days with or without clodronate in the presence of vitamin D and analyzed the number of osteoclasts formed and the amount of TRAP 5b activity released into the culture medium.Results: TRAP 5b activity was not secreted from osteoclast precursor cells. Addition of clodronate-containing liposomes decreased in a dose-dependent manner the number of osteoclasts and TRAP 5b activity released in 6-day cultures. The amount of TRAP 5b activity in the medium detected by the immunoassay correlated significantly with the number of osteoclasts formed (r = 0.94; P &lt;0.0001; n = 120).Conclusions: The TRAP 5b immunoassay can be used to replace the laborious and time-consuming microscopic counting of osteoclasts in the osteoclast differentiation assay and to test the effects of potential therapeutic agents on osteoclast differentiation, enabling fast screening of large amounts of potential therapeutic agents.
Determination of the Glycoforms of Human Chorionic Gonadotropin β-Core Fragment by Matrix-assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry
Authors: Jacoby Eli S , Kicman Andrew T , Laidler Paul , Iles Ray K 
Published: January 2020

AbstractBackground: Metabolism of human chorionic gonadotropin (hCG) in the serum and kidney yields the terminal urinary product hCG β-core fragment (hCGβcf), comprising two disulfide-linked peptides (β6-β40 and β55-β92) of which one (β6-β40) retains truncated N-linked sugars. Hyperglycosylated hCGβcf may indicate choriocarcinoma or Down syndrome, but the glycosylation profile of hCGβcf has not been thoroughly evaluated.Methods: hCGβcf, purified from pregnancy urine, was reduced by “on-target” dithiothreitol (DTT) reduction and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass ([M+H]+) of the primary sequence of the glycosylated peptide β6-β40 was subtracted from the m/z values of the discrete peaks observed to give the masses of the carbohydrate moieties. Carbohydrate structure was predicted by sequentially subtracting the masses of the monosaccharide residues corresponding to N-linked carbohydrates of the hCG β-subunit reported in the literature.Results: Mass spectra of hCGβcf revealed a broad triple peak at m/z 8700–11300. After reduction, the triple peak was replaced by a discrete set of peaks between m/z 4156 and 6354. A peak at m/z 4156.8 corresponded to the nonglycosylated peptide (β55-β92). The remaining nine peaks indicated that urinary hCGβcf comprises a set of glycoforms smaller and larger than the trimannosyl core.Conclusions: hCGβcf comprises a wider set of glycoforms than reported previously. Peaks of highest mass indicate evidence of hyperglycosylated carbohydrate moieties. The data support previous reports that hCGβcf oligosaccharides lack sialic acid and galactose residues. No indication was found of a β6-β40 peptide that was entirely devoid of carbohydrate.
Evaluation of LabRespond, a New Automated Validation System for Clinical Laboratory Test Results
Authors: Oosterhuis Wytze P , Ulenkate Herman J L M , Goldschmidt Henk M J 
Published: January 2020

Abstract
Background: Manual validation of laboratory test results is time-consuming, creating a demand for expert systems to automate this process. We have started to set up the program “LabRespond”, which covers five validation levels: administrative, technical, sample, patient, and clinical validation. We present the evaluation of a prototype of an automated patient validation system based on statistical methods, in contrast to the commercially available program “VALAB”, a rule-based automated validation system.
Methods: In the present study, 163 willfully altered, erroneous test results out of 5421 were submitted for validation to LabRespond, VALAB, and to a group of clinical chemists (n = 9) who validated these test results manually. The test results rejected by three or more clinical chemists (n = 281) served as a secondary reference standard.
Results: The error recovery rates of clinical chemists ranged from 23.9% to 71.2%. The recovery rates of LabRespond and VALAB were 77.9% and 71.8%, respectively (difference not significant). The false-positive rates were 82.7% for LabRespond, 83.6% for VALAB, and 27.8–86.7% for clinical chemists. Using the consensus of three or more clinical chemists as the secondary reference standard, we found error recovery rates of 64.8% for LabRespond and 72.2% for VALAB (P = 0.06). Compared with VALAB, LabRespond detected more (P = 0.003) erroneous test results of the type that were changed from abnormal to normal.
Conclusions: The statistical plausibility check used by LabRespond offers a promising automated validation method with a higher error recovery rate than the clinical chemists participating in this study, and a performance comparable to VALAB.
The Role of the Clinical Laboratory in Managing Chemical or Biological Terrorism
Authors: Jortani Saeed A , Snyder James W , Valdes Jr Roland 
Published: January 2020

Abstract
Background: Domestic and international acts of terrorism using chemicals and pathogens as weapons have recently attracted much attention because of several hoaxes and real incidents. Clinical laboratories, especially those affiliated with major trauma centers, should be prepared to respond rapidly by providing diagnostic tests for the detection and identification of specific agents, so that specific therapy and victim management can be initiated in a timely manner. As first-line responders, clinical laboratory personnel should become familiar with the various chemical or biological agents and be active participants in their local defense programs.
Approach: We review the selected agents previously considered or used in chemical and biological warfare, outline their poisonous and pathogenic effects, describe techniques used in their identification, address some of the logistical and technical difficulties in maintaining such tests in clinical laboratories, and comment on some of the analytical issues, such as specimen handling and personal protective equipment.
Content: The chemical agents discussed include nerve, blistering, and pulmonary agents and cyanides. Biological agents, including anthrax and smallpox, are also discussed as examples for organisms with potential use in bioterrorism. Available therapies for each agent are outlined to assist clinical laboratory personnel in making intelligent decisions regarding implementation of diagnostic tests as a part of a comprehensive defense program.
Summary: As the civilian medical community prepares for biological and chemical terrorist attacks, improvement in the capabilities of clinical laboratories is essential in supporting counterterrorism programs designed to respond to such attacks. Accurate assessment of resources in clinical laboratories is important because it will provide local authorities with an alternative resource for immediate diagnostic analysis. It is, therefore, recommended that clinical laboratories identify their current resources and the extent of support they can provide, and inform the authorities of their state of readiness.
Synergistic Effect between Apolipoprotein E and Angiotensinogen Gene Polymorphisms in the Risk for Early Myocardial Infarction
Authors: Batalla Alberto , Alvarez Ruth , Reguero Julián R , Hevia Sergio , Iglesias-Cubero Gustavo , Alvarez Victoria , Cortina Arturo , González Pelayo , Celada Mateo M , Medina Alfonso , Coto Eliecer 
Published: January 2020

AbstractBackground: Several studies based on different populations worldwide have described an association between cardiovascular diseases and genetic variations in the apolipoprotein E (APOE), angiotensinogen (AGT), angiotensin receptor type 1 (AT1R), and angiotensin-converting enzyme (ACE) genes. In addition, there is growing evidence of an interaction between hypercholesterolemia and the renin-angiotensin system in the risk for hypertension and atherosclerosis.Methods: To determine whether the DNA polymorphisms in APOE (ε2, ε3, and ε4 alleles), AGT (M235T), AT1R (1166 A/C), and ACE (I/D) are associated with early onset of myocardial infarction (MI), we genotyped 220 patients and 200 controls &lt;55 years of age. Patients and controls were males from the same homogeneous Caucasian population. Data concerning hypertension, diabetes, and tobacco consumption were recorded. The lipid profiles of patients and controls were also determined.Results: APOE, ACE, AGT, and AT1R allele and genotype frequencies did not differ between patients and controls. None of these polymorphisms was related to the biochemical values in patients or controls. The frequency of individuals who were both APOEε4 allele carriers and AGT-TT homozygotes was significantly higher in patients than in controls (11% vs 3.5%; P = 0.0037). In patients, the frequency of ε4 carriers was significantly higher (P &lt;0.00001) in those who were AGT-TT (46%) than those who were AGT-MT/MM (14%). Mean cholesterol was significantly higher in AGT-TT + APOE ε34/44 patients than in the TM/MM + ε34/44 or TT + ε23/33 genotypes (P = 0.029).Conclusions: Our data suggest a synergistic effect between the APOE and AGT polymorphisms and early MI. The increased risk could be mediated in part through higher cholesterol concentrations among individuals who are AGT-TT + APOEε4 allele carriers.
A Modified, Optimized Kinetic Photometric Assay for the Determination of Blood Coagulation Factor XIII Activity in Plasma
Authors: Kárpáti Levente , Penke Botond , Katona Éva , Balogh István , Vámosi György , Muszbek László 
Published: January 2020

AbstractBackground: Blood coagulation factor XIII (FXIII) is a zymogen that is transformed into an active transglutaminase by thrombin and Ca2+. FXIII plays an essential role in fibrin stabilization and in the protection of fibrin from proteolytic degradation. No convenient method has been available for the measurement of FXIII activity in plasma. The aim of the present study was to improve and optimize a kinetic photometric FXIII assay originally developed in our laboratory.Methods: In the assay, FXIII was activated by thrombin and Ca2+. Fibrin polymerization was prevented by an inhibitory tetrapeptide. Glycine-ethyl ester and a glutamine residue of a synthetic dodecapeptide served as acyl acceptor and acyl donor transglutaminase substrates, respectively. The amount of ammonia released during the reaction was monitored using glutamate dehydrogenase and NADPH.Results: The use of a new glutamine substrate and optimization of activator and substrate concentrations increased sensitivity. Substitution of NADPH for NADH and introduction of an appropriate blank eliminated systemic overestimation of FXIII activity. The recovery of FXIII was 96%, the assay was linear up to 470 U/L, the detection limit was 1 U/L, and the imprecision (CV) was &lt;8% even at very low FXIII activities. A reference interval of 108–224 U/L (69–143%) was established. The results correlated well with results obtained by an immunoassay specific for plasma FXIII.Conclusions: The optimized FXIII assay is a simple, rapid method for the diagnosis of inherited or acquired FXIII deficiencies and increased FXIII concentrations. It can be easily adapted to clinical chemistry analyzers.