bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation between Plasma Total Homocysteine and Copper in Patients with Peripheral Vascular Disease
Authors: Mansoor Mohammad A , Bergmark Claes , Haswell Steve J , Savage Ian F , Evans Peter H , Berge Rolf K , Svardal Asbjørn M , Kristensen Ole 
Published: January 2020

AbstractBackground: Increased concentrations of both plasma total homocysteine and copper are separately associated with cardiovascular disease. Correlations between plasma total homocysteine, trace elements, and vitamins in patients with peripheral vascular disease have not been investigated.Methods: The concentrations of trace elements in plasma were determined by the multielement analytical technique of total-reflection x-ray fluorescence spectrometry. Plasma total homocysteine was determined by HPLC.Results: In the univariate and multivariate regression analyses, copper was positively correlated with plasma total homocysteine in all subjects (coefficient ± SE, 0.347 ± 0.113; P = 0.0026 and coefficient ± SE, 0.422 ± 0.108; P = 0.0002, respectively), and in patients with peripheral vascular disease (coefficient ± SE, 0.370 ± 0.150; P = 0.016; and coefficient ± SE, 0.490 ± 0.151; P = 0.0025, respectively). Correlation between copper and plasma total homocysteine was not detected in healthy control subjects. The concentration of calcium in plasma (67.5 vs 80.8 μg/g) was significantly lower in the patients than in the control subjects (P = 0.02). When the patients were divided into groups, the patients with suprainguinal lesions had significantly higher copper concentrations (P = 0.04) and significantly lower selenium and calcium concentrations (P = 0.01 and 0.008, respectively) than the healthy subjects. Patients had higher concentrations of autoantibodies against oxidized LDL and concentrations of thiobarbituric acid-reactive substance than the healthy subjects (P &lt;0.0001 and P = 0.001, respectively). The concentrations of plasma total homocysteine and α-tocopherol were significantly higher, and the concentrations of vitamin B6 and β-carotene were lower in the patients than the healthy subjects.Conclusion: Our findings suggest that the atherogenicity of homocysteine may be related to copper-dependent interactions.
Cerebrospinal Fluid Protein Concentrations in Children: Age-related Values in Patients without Disorders of the Central Nervous System
Authors: Biou Daniel , Benoist Jean-François , Nguyen-Thi Claire , Huong Xuan , Morel Philippe , Marchand Martine 
Published: January 2020

Abstract
Background: The published reference values for cerebrospinal fluid (CSF) total protein concentrations in children suffer from two major drawbacks: (a) the age-related range often is too broad when applied to the steeply falling concentrations in early infancy; and (b) no values have been published for widely used dry chemistry methods.
Methods: We conducted a 2-year retrospective survey of CSF results obtained in a children’s hospital with a dry chemistry-based method set up on the Vitros 700 analyzer.
Results: The data related to ambulatory children up to 16 years of age and term neonates with no clinical or biological signs of brain disease (n = 1074). Seven age groups with significantly different CSF protein values were identified, and their age-related percentiles (5th, 50th, and 95th) were determined. On the basis of the upper 95th percentile, from age 0 to 6 months the CSF protein concentrations fell rapidly from 1.08 to 0.40 g/L. A plateau (0.32 g/L) was reached from age 6 months to 10 years, followed by a slight increase (0.41 g/L) in the 10–16 years age range.
Conclusions: These results imply that CSF total protein concentrations in the pediatric setting, particularly in infants, must always be interpreted with regard to narrow age-related reference values to avoid false-positive results.
Rapid Screening of High-Risk Patients for Disorders of Purine and Pyrimidine Metabolism Using HPLC-Electrospray Tandem Mass Spectrometry of Liquid Urine or Urine-soaked Filter Paper Strips
Authors: Ito Tetsuya , van Kuilenburg André B P , Bootsma Albert H , Haasnoot Anja J , van Cruchten Arno , Wada Yoshiro , van Gennip Albert H 
Published: January 2020

Abstract
Background: A rapid and specific screening method for patients at risk of inherited disorders of purine and pyrimidine metabolism is desirable because symptoms are varied and nonspecific. The aim of this study was to develop a rapid and specific method for screening with use of liquid urine samples or urine-soaked filter paper strips.
Methods: Reverse-phase HPLC was combined with electrospray ionization (ESI), tandem mass spectrometry (MS/MS), and detection performed by multiple reaction monitoring. Transitions and instrument settings were established for 17 purines or pyrimidines. Stable-isotope-labeled reference compounds were used as internal standards when available.
Results: Total analysis time of this method was 15 min, approximately one-third that of conventional HPLC with ultraviolet detection. Recoveries were 96–107% in urine with added analyte, with two exceptions (hypoxanthine, 64%; xanthine, 79%), and 89–110% in urine-soaked filter paper strips, with three exceptions (hypoxanthine, 65%; xanthine, 77%; 5-hydroxymethyluracil, 80%). The expected abnormalities were easily found in samples from patients with purine nucleoside phosphorylase deficiency, ornithine transcarbamylase deficiency, molybdenum cofactor deficiency, adenylosuccinase deficiency, or dihydropyrimidine dehydrogenase deficiency.
Conclusions: HPLC-ESI MS/MS of urine allows rapid screening for disorders of purine and pyrimidine metabolism. The filter paper strips offer the advantage of easy collection, transport, and storage of the urine samples.
Evaluation of Four Automated High-Sensitivity C-Reactive Protein Methods: Implications for Clinical and Epidemiological Applications
Authors: Roberts William L , Sedrick Rachel , Moulton Linda , Spencer Anthony , Rifai Nader 
Published: January 2020

AbstractBackground: C-reactive protein (CRP) can provide prognostic information about the risk of developing atherosclerotic complications in apparently healthy patients. This new clinical application requires quantification of CRP concentrations below those traditionally measured in the clinical laboratory.Methods: The Dade Behring BN II, the Abbott IMx, the Diagnostic Products Corporation IMMULITE, and the Beckman Coulter IMMAGE are four automated analyzers with high-sensitivity CRP (hs-CRP) methods. We evaluated these assays for precision, linearity, and comparability with samples from 322 apparently healthy blood donors.Results: The imprecision (CV) of the BN II, IMx, IMMULITE, and IMMAGE methods was ≤7.6%, ≤12%, ≤9.8%, and ≤9.7% at 3.5 mg/L, respectively. The BN II, IMx, IMMULITE, and IMMAGE methods were linear down to ≤0.30, ≤0.32, ≤0.85, and 2.26 mg/L, respectively. CRP concentrations demarcating each quartile in a healthy population were method dependent. The IMx method gave results comparable to the BN II method for values in the reference interval. The IMMULITE method had a positive intercept compared with the BN II method. The IMMAGE method demonstrated more scatter and a positive intercept compared with the BN II method, which may reflect the fact that it is a less sensitive assay.Conclusions: The four hs-CRP methods exhibited differences in results for a healthy population. Additional standardization efforts are required to ensure that hs-CRP results can be related to large-scale epidemiologic studies.
Simple Microplate Method for Determination of Urinary Iodine
Authors: Ohashi Toshinori , Yamaki Mitsuo , Pandav Chandrakant S , Karmarkar Madhu G , Irie Minoru 
Published: January 2020

Abstract
Background: Urinary iodine is a good biochemical marker for control of iodine deficiency disorders. Our aim was to develop and validate a simple, rapid, and quantitative method based on the Sandell–Kolthoff reaction, incorporating both the reaction and the digestion process into a microplate format.
Methods: Using a specially designed sealing cassette to prevent loss of vapor and cross-contamination among wells, ammonium persulfate digestion was performed in a microplate in an oven at 110 °C for 60 min. After the digestion mixture was transferred to a transparent microplate and the Sandell–Kolthoff reaction was performed at 25 °C for 30 min, urinary iodine was measured by a microplate reader at 405 nm.
Results: The mean recovery of iodine added to urine was 98% (range, 89–109%). The theoretical detection limit, defined as 2 SD from the zero calibrator, was 0.11 μmol/L (14 μg/L iodine). The mean intra- and interassay CVs for samples with iodine concentrations of 0.30–3.15 μmol/L were ≤10%. The new method agreed well with the conventional chloric acid digestion method (n = 70; r = 0.991; y = 0.944x + 0.04; Sy|x = 0.10) and with the inductively coupled plasma mass spectrometry method (n = 61; r = 0.979; y = 0.962x + 0.03; Sy|x = 0.20). The agreement was confirmed by difference plots. The distributions of iodine concentrations for samples from endemic areas of iodine deficiency diseases showed similar patterns among the above three methods.
Conclusions: Our new method, incorporating the whole process into a microplate format, is readily applicable and allows rapid monitoring of urinary iodine.
Current Concepts in Biomarker Technology for Bladder Cancers
Authors: Burchardt Martin , Burchardt Tatjana , Shabsigh Ahmad , De La Taille Alexandre , Benson Mitchell C , Sawczuk Ihor 
Published: January 2020

AbstractBackground: Transitional cell carcinoma of the bladder (TCC) is the second most common malignancy of the urinary tract. More than 70% of treated tumors recur, and 30% of recurrent tumors progress. Currently, pathologic staging and grading are valuable prognostic factors for detecting and monitoring TCC. Urinalysis, cystoscopy, and cytology are either invasive or lack sensitivity and specificity. The availability of a noninvasive, reliable, and simple test would greatly improve the detection and monitoring of patients with TCC. Several biomarkers for bladder cancer have been proposed, but no single marker has emerged as the test of choice.Approach: We undertook a comprehensive literature search using Medline to identify all publications from 1980 to 1999. Articles that discussed potential biomarkers for TCC were screened. Only compounds that demonstrated high sensitivity or specificity, significant correlation with TCC diagnosis and staging, and extensive investigation were included in this review.Content: Potential biomarkers of disease progression and prognosis include nuclear matrix protein, fibrin/fibrinogen product, bladder tumor antigen, blood group-related antigens, tumor-associated antigens, proliferating antigens, oncogenes, growth factors, cell adhesion molecules, and cell cycle regulatory proteins. The properties of the biomarkers and the methods for detecting or quantifying them are presented. Their sensitivities and specificities for detecting and monitoring disease were 54–100% and 61–97%, respectively, compared with 20–40% and 90% for urinalysis and cytology.Summary: Although urine cytology and cystoscopy are still the standard of practice, many candidate biomarkers for TCC are emerging and being adopted into clinical practice. Further research and better understanding of the biology of bladder cancer, improved diagnostic techniques, and standardized interpretation are essential steps to develop reliable biomarkers. It is possible that using the current biomarkers as an adjuvant modality will improve our ability to diagnose and monitor bladder cancer.
Detection of Rare Mutant Alleles by Restriction Endonuclease-mediated Selective-PCR: Assay Design and Optimization
Authors: Fuery Caroline J , Impey Helen L , Roberts Natalie J , Applegate Tanya L , Ward Robyn L , Hawkins Nicholas J , Sheehan Catherine A , O’Grady Roslyn , Todd Alison V 
Published: January 2020

Abstract
Background: Restriction endonuclease-mediated selective (REMS)-PCR, allows detection of point mutations, deletions, and insertions. Reactions require concurrent activity of a restriction endonuclease (RE) and a DNA polymerase, both of which must be sufficiently thermostable to retain activity during thermocycling. The inclusion of the RE in REMS-PCR inhibits amplification of sequences containing the RE recognition site, thus producing selective amplification of sequences that lack the RE site.
Methods: Assays were used that allowed the selection of conditions that produce concurrent RE/DNA polymerase activity. The RE thermostability assay involved thermocycling a RE under various conditions and assessing residual cleavage activity at various time points. Conditions found to preserve RE activity during thermocyling were then tested for their compatibility with DNA polymerase-mediated PCR.
Results: A range of conditions that preserve activity of the RE BstNI over 30 cycles of PCR was identified. A subset of these conditions was subsequently found to mediate specific amplification using Taq DNA polymerase. These conditions were used to develop a REMS-PCR protocol for the detection of mutations at codon 12 of the K-ras gene. This protocol allowed the detection of 1 mutant allele in a background of 1000 wild-type alleles. The presence of primer sets for RE and PCR control amplicons provided unambiguous assessment of mutant status.
Conclusion: Implementation of the assays described may facilitate development of REMS-PCR assays targeted to other loci associated with disease.
The Plasma Homocysteine Concentration Is Better Than That of Serum Methylmalonic Acid as a Marker for Sociopsychological Performance in a Psychogeriatric Population
Authors: Nilsson Karin , Gustafson Lars , Hultberg Björn 
Published: January 2020

AbstractBackground: Cobalamin/folate deficiency in elderly subjects may lead to psychiatric symptoms, but more often it increases the severity of various organic and nonorganic mental diseases. A major clinical problem, however, is the uncertainty and controversy concerning biochemical markers of cobalamin/folate deficiency to be used in the diagnostic evaluation of suspected cobalamin/folate deficiency.Methods: We measured plasma homocysteine (tHcy), blood folate, serum methylmalonic acid, and serum cobalamin in 80 psychogeriatric patients (age, 77.3 ± 8.6 years) and 50 controls (age, 76.1 ± 8.0 years). We assessed associations of these tests with measures of cognitive and behavior performance by use of regression analyses.Results: Plasma tHcy was increased in 45% of the psychogeriatric population (mean, 20.5 ± 9.2 μmol/L vs 15.3 ± 4.7 μmol/L for controls; P &lt;0.01). Plasma tHcy correlated with severity of dementia (r = 0.36; P &lt;0.01), the Katz ADL index (r = 0.29; P &lt;0.05), the Berger scale (r = 0.29; P &lt;0.05), and the score of symptoms (r = 0.39; P &lt;0.001) in the psychogeriatric population. Similarly, blood folate was significantly correlated with these measures, but the concentrations of serum cobalamin and methylmalonic acid were not. In a stepwise multiple regression analysis including the biochemical markers, tHcy was the only significant predictor of the severity of dementia (r2 = 0.11; P &lt;0.01) and the score of symptoms (r2 = 0.16; P &lt;0.001).Conclusion: Plasma tHcy is the best marker of those measured to investigate suspected tissue deficiency of cobalamin/folate.
Vitamin B1 Status Assessed by Direct Measurement of Thiamin Pyrophosphate in Erythrocytes or Whole Blood by HPLC: Comparison with Erythrocyte Transketolase Activation Assay
Authors: Talwar Dinesh , Davidson Helen , Cooney Josephine , St. JO’Reilly Denis 
Published: January 2020

Abstract
Background: The concentration of thiamin diphosphate (TDP) in erythrocytes is a useful index of thiamin status. We describe an HPLC method for TDP and its results in patients at risk of thiamin deficiency.
Methods: We used reversed-phase HPLC with postcolumn derivatization with alkaline potassium ferricyanide and fluorescence detection. Samples were deproteinized and injected directly onto a C18 column. TDP concentrations in erythrocytes were compared with those in whole blood. Reference intervals for erythrocyte TDP (n = 147; 79 males and 68 females; mean age, 54 years) and whole blood TDP (n = 124; 68 males and 56 females; mean age, 54 years) were determined in an apparently healthy population. We compared erythrocyte TDP with results of the erythrocyte transketolase activation test in 63 patients who were considered at risk of thiamin deficiency.
Results: The method was linear to at least 200 μg/L. The between-run CV was &lt;8%. The lower limit of quantification for both whole blood and packed erythrocytes was 300 pg on column with a detection limit of 130 pg on column. Recovery of TDP from blood samples was &gt;90%. TDP in erythrocytes correlated strongly with that in whole blood (r = 0.97). Reference intervals for erythrocyte and whole blood TDP were 280–590 ng/g hemoglobin and 275–675 ng/g hemoglobin, respectively. Of the 63 patients suspected of thiamin deficiency, 46 were normal by both TDP and activation tests, 13 were deficient by both tests, 1 was deficient by the activation test but had normal erythrocyte TDP concentrations, and 4 were normal by the activation test but had low TDP.
Conclusions: The HPLC method is precise and yields results similar to the erythrocyte activation assay.
Developing an Automation Concept That Is Right for Your Laboratory
Authors: Middleton Stephen R 
Published: January 2020

Abstract
Background: Trends in laboratory automation and critical project principles and design concepts are presented.
Approach: MDS AutoLab technology development and automation projects were reviewed. Successful methods and approaches were extracted.
Issues: Continued pressure on the laboratory to reduce costs and increase productivity has catalyzed dramatic development in laboratory automation. Today, laboratories can choose from a wide range of options. The most effective choices are not always the most obvious and will not be the same for all laboratories. Laboratory automation projects are highly complex and must be planned and managed across clinical, technical, operational, financial, and human dimensions.
Conclusions: Success requires excellent communications, an understanding of the risks and barriers, and a dedicated team supported by strong champions throughout the organization. The automation project team will need to use a variety of skills and techniques to evaluate and reengineer processes to identify the highest value targets for automation.
Protein Glycosylation and Diseases: Blood and Urinary Oligosaccharides as Markers for Diagnosis and Therapeutic Monitoring
Authors: Durand Geneviève , Seta Nathalie 
Published: January 2020

AbstractBackground: N- and O-oligosaccharide variants on glycoproteins (glycoforms) can lead to alterations in protein activity or function that may manifest themselves as overt disease.Approach: This review summarizes those diseases that are known to be the result of an inherited or acquired glycoprotein oligosaccharide structural alteration and that are diagnosed in blood or urine by chemical characterization of that oligosaccharide alteration.Content: The biochemical synthesis steps and catabolic pathways important in determining glycoprotein function are outlined with emphasis on alterations that lead to modified function. Clinical and biochemical aspects of the diagnosis are described for inherited diseases such as I-cell disease, congenital disorders of glycosylation, leukocyte adhesion deficiency type II, hereditary erythroblastic multinuclearity with a positive acidified serum test, and Wiskott-Aldrich syndrome. We also review the laboratory use of measurements of glycoforms related to acquired diseases such as alcoholism and cancer.Conclusions: Identification of glycoprotein glycoforms is becoming an increasingly important laboratory contribution to the diagnosis and management of human diseases as more diseases are found to result from glycan structural alterations.
Troponin T and I Assays Show Decreased Concentrations in Heparin Plasma Compared with Serum: Lower Recoveries in Early than in Late Phases of Myocardial Injury
Authors: Gerhardt Willie , Nordin Gunnar , Herbert Ann-Katrin , Linåker Burzell Birgitta , Isaksson Anders , Gustavsson Elisabeth , Haglund Sofie , Müller-Bardorff Margit , Katus Hugo A 
Published: January 2020

AbstractBackground: Heparinized plasma samples allow more rapid analysis than serum samples, but preliminary studies showed lower cardiac troponin T (cTnT) results in plasma. We undertook a multicenter study to characterize this effect for cTnT and cardiac troponin I (cTnI).Methods: Blood samples were collected with and without heparin at five hospitals. cTnT was measured by a “third generation” assay (Elecsys®), and cTnI was measured by a commercial immunoassay (IMMULITE®).Results: Mean cTnT was 15% lower in heparin sampling tubes than in serum. Measured concentrations of cardiac troponins also decreased with increasing heparin concentrations added to sera. Heparin-induced losses were greater in early than in late phases after onset of chest pain. Addition of heparin (∼100 IU/mL) to serial samples from nine acute myocardial infarction patients produced mean cTnT losses of 33% at 1–12 h after onset of chest pain, 17% at 13–48 h, and 7% after 48 h. The changing heparin effects were seen for both cTnT and cTnI during time courses of individual patients with myocardial infarction.Conclusion: We suggest that binding of heparin to troponins decreases immunoreactivity, especially in early phases of myocardial injury. The resulting losses may depend on the antibodies used in each troponin assay.
Age-related Increases in Plasma Phosphatidylcholine Hydroperoxide Concentrations in Control Subjects and Patients with Hyperlipidemia
Authors: Kinoshita Mikio , Oikawa Shinichi , Hayasaka Kyoko , Sekikawa Akihiro , Nagashima Tazuko , Toyota Takayoshi , Miyazawa Teruo 
Published: January 2020

AbstractBackground: The basal lipid peroxide concentration in the plasma of patients with hyperlipidemia may be related to atherosclerosis. Quantitative determination of lipid peroxides in the plasma is an important step in the overall evaluation of the biochemical processes leading to oxidative injury. Unfortunately, the currently available methods for lipid peroxidation lack specificity and sensitivity.Methods: Hyperlipidemic patients (44 males and 50 females), ages 12–82 years (mean ± SE, 53 ± 2.3 years for males, 58 ± 2.0 years for females, and 56 ± 14 years for total cases), and normolipidemic volunteers (controls, 32 males and 15 females), ages 13–90 years (49 ± 4 years for males, 65 ± 4 years for females, and 55 ± 24 years for total cases), were recruited in the present study. Plasma phosphatidylcholine hydroperoxide (PCOOH) was determined by chemiluminescence-HPLC (CL-HPLC).Results: Plasma PCOOH concentrations increased with age in both controls and hyperlipidemic patients. However, the mean plasma PCOOH concentration in patients with hyperlipidemia (331 ± 19 nmol/L; n = 94) was significantly (P &lt;0.001) higher than in the controls (160 ± 65 nmol/L; n = 47). Plasma PCOOH concentrations were similar in three hyperlipidemic phenotypes: hypercholesterolemia (IIa), hypertriglyceridemia (IV), and combined hyperlipidemia (IIb). The mean plasma PCOOH in patients with treatment-induced normalized plasma lipids was 202 ± 17 nmol/L. There was no significant correlation between plasma PCOOH concentration and total cholesterol, triglycerides, or phospholipids in hyperlipidemic patients. For all subjects, there was a significantly positive correlation between plasma PCOOH and each lipid (total cholesterol, P = 0.0002; triglycerides, P = 0.0137; and phospholipids, P &lt;0.0001). Analysis of fatty acids composition of plasma phosphatidylcholine showed significantly low concentrations of n-6 fatty acids moieties (linoleic acid and arachidonic acid) in patients compared with controls.Conclusions: Our results suggest that an increase in plasma PCOOH in patients with hyperlipidemia may be related to the development and progression of atherosclerosis, particularly in the elderly. Measurement of plasma PCOOH is useful for in vivo evaluation of oxidative stress.