bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical and Experimental Results on Cardiac Troponin Expression in Duchenne Muscular Dystrophy
Authors: Hammerer-Lercher Angelika , Erlacher Petra , Bittner Reginald , Korinthenberg Rudolf , Skladal Daniela , Sorichter Stephan , Sperl Wolfgang , Puschendorf Bernd , Mair Johannes 
Published: January 2020

AbstractBackground: Because of controversial earlier studies, the purpose of this study was to provide novel experimental and additional clinical data regarding the possible reexpression of cardiac troponin T (cTnT) in regenerating skeletal muscle in Duchenne muscular dystrophy (DMD).Methods: Plasma from 14 patients (mean age, 7.5 years; range, 5.7–19.4 years) with DMD was investigated for creatine kinase (CK), the CK MB isoenzyme (CKMB), cTnT and cardiac troponin I (cTnI), and myoglobin. cTnT concentrations were measured by an ELISA (second-generation assay; Roche) using the ES 300 Analyzer. cTnI, myoglobin, and CKMB were measured by an ELISA using the ACCESS System (Beckman Diagnostics). Troponin isoform expression was studied by Western blot analysis in remnants of skeletal muscle biopsies of three patients with DMD and in an animal model of DMD (mdx mice; n = 6).Results: There was no relation of cTnT and cTnI to clinical evidence for cardiac failure. cTnI concentrations remained below the upper reference limit in all patients. cTnT was increased (median, 0.11 μg/L; range, 0.06–0.16 μg/L) in 50% of patients. The only significant correlation was found for CK (median, 3938 U/L; range, 2763–5030 U/L) with age (median, 7.5 years; range, 6.8–10.9 years; r = −0.762; P = 0.042). Western blot analysis of human or mouse homogenized muscle specimens showed no evidence for cardiac TnT and cTnI expression, despite strong signals for skeletal muscle troponin isoforms.Conclusions: We found no evidence for cTnT reexpression in human early-stage DMD and in mdx mouse skeletal muscle biopsies. Discrepancies of cTnT and cTnI in plasma samples of DMD patients were found, but neither cTnT nor cTnI plasma concentrations were related with other clinical evidence for cardiac involvement.
Effects of Implantable Cardioverter Defibrillator Implantation and Shock Application on Biochemical Markers of Myocardial Damage
Authors: Schlüter Thomas , Baum Hannsjörg , Plewan Andreas , Neumeier Dieter 
Published: January 2020

Abstract
Background: Implantable cardioverter defibrillator (ICD) implantation is a common approach in patients at high risk of sudden cardiac death. To check for normal function, it is necessary to test the ICD. For this purpose, repetitive induction and termination of ventricular fibrillation by direct current shocks is required. This may lead to minor myocardial damage. Cardiac troponin T (cTnT) and I (cTnI) are specific markers for the detection of myocardial injury. Because these proteins usually are undetectable in healthy individuals, they are excellent markers for detecting minimal myocardial damage. The objective of this study was to evaluate the effect of defibrillation of induced ventricular fibrillation on markers of myocardial damage.
Methods: This study included 14 patients who underwent ICD implantation and intraoperative testing. We measured cTnT, cTnI, creatine kinase MB (CK-MB) mass, CK activity, and myoglobin before and at definite times after intraoperative shock application.
Results: Depending on the effectiveness of shocks and the energy applied, the cardiac-specific markers cTnT and cTnI, as well as CK-MB mass, showed a significant increase compared with the baseline value before testing and peaked for the most part 4 h after shock application. In contrast, the increases in CK activity and myoglobin were predominantly detectable in patients who received additional external shocks.
Conclusions: ICD implantation and testing leads to a short release of cardiac markers into the circulation. This release seems to be of cytoplasmic origin and depends on the number and effectiveness of the shocks applied.
Diagnosis of Dopa-responsive Dystonia and Other Tetrahydrobiopterin Disorders by the Study of Biopterin Metabolism in Fibroblasts
Authors: Bonafé Luisa , Thöny Beat , Leimbacher Walter , Kierat Lucja , Blau Nenad 
Published: January 2020

AbstractBackground: Dopa-responsive dystonia (DRD) and tetrahydrobiopterin (BH4) defects are inherited disorders characterized by monoamine neurotransmitter deficiency with decreased activity of one of the BH4-metabolizing enzymes. The aim of the study was to determine the utility of cultured skin fibroblasts for the diagnosis of these diseases.Methods: Neopterin and biopterin production and GTP cyclohydrolase I (GTPCH) activity were measured in cytokine-stimulated fibroblasts; 6-pyruvoyltetrahydropterin synthase (PTPS), sepiapterin reductase (SR), and dihydropteridine reductase (DHPR) activities were measured in unstimulated fibroblasts. We examined 8 patients with DRD, 3 with autosomal recessive GTPCH deficiency, 7 with PTPS deficiency, 3 with DHPR deficiency, and 49 controls (35 fibroblast and 14 amniocyte samples).Results: Fibroblasts from patients with DRD and autosomal recessive GTPCH deficiency showed reduced GTPCH activity (15.4% and 30.7% of normal activity, respectively) compared with controls (P &lt;0.001). Neopterin production was very low and biopterin production was reduced in both disorders. PTPS- and DHPR-deficient cells showed no enzyme activities; in PTPS deficiency the pattern of pterin production was typical (neopterin, 334–734 pmol/mg; controls, 18–98 pmol/mg; biopterin, 0 pmol/mg; controls, 154–303 pmol/mg). Reference values of all enzyme activities and pterin production were measured in fibroblasts and also in amniocytes for prenatal diagnosis.Conclusions: Cultured skin fibroblasts are a useful tool in the diagnosis of BH4 deficiencies. Intracellular neopterin and biopterin concentrations and GTPCH activity in cytokine-stimulated fibroblasts are particularly helpful in diagnosing patients with DRD.
Triple Lipid Screening Test: A Homogeneous Sequential Assay for HDL-Cholesterol, Total Cholesterol, and Triglycerides
Authors: Sampson Maureen L , Aubry Andrea , Csako Gyorgy , Remaley Alan T 
Published: January 2020

Abstract
Background: The analysis of lipids in serum lipoprotein fractions is useful in assessing the risk for coronary artery disease, but it typically involves performing multiple tests. An automated single-tube assay, referred to as the triple lipid screening (TLS) test, can be used for measuring HDL-cholesterol (HDL-C), total cholesterol, and triglycerides (TGs) with no specimen pretreatment.
Methods: The first part of the assay is based on a homogeneous assay for HDL-C that uses either an anti-apolipoprotein B antibody (TLS-A test) or a polyanion (TLS-B test) that blocks the enzymatic measurement of cholesterol on the non-HDL fraction. After the addition of deoxycholate, which solubilizes the unreacted cholesterol from the non-HDL fraction, the remaining cholesterol in the sample is subsequently measured enzymatically. Using the same enzyme detection system as the cholesterol assay, TGs are measured in the last step, after the addition of the enzymes for the TG assay.
Results: The TLS assay (y) had acceptable analytic performance and compared favorably with standard tests (x) for each analyte: for HDL-C, TLS-A = 0.99x + 0.19 (R = 0.980); TLS-B = 1.00x − 0.15 (R = 0.974); for total cholesterol, TLS-A = 1.03x + 0.12 (R = 0.997); TLS-B = 1.07x − 0.30 (R = 0.965); and for TGs, TLS-A = 1.02x + 0.02 (R = 0.988); TLS-B = 1.04x − 0.28 (R = 0.980).
Conclusions: The TLS test is a single-tube homogeneous assay for the analysis of all of the major serum lipoprotein fractions and can be used as a simple screening test for the detection of hyperlipidemia.
Measurement of Circulating Forms of Prostate-specific Antigen in Whole Blood Immediately after Venipuncture: Implications for Point-of-Care Testing
Authors: Piironen Timo , Nurmi Martti , Irjala Kerttu , Heinonen Olli , Lilja Hans , Lövgren Timo , Pettersson Kim 
Published: January 2020

AbstractBackground: The purpose of this study was to validate the use of whole-blood samples in the determination of circulating forms of prostate-specific antigen (PSA).Methods: Blood samples of hospitalized prostate cancer and benign prostatic hyperplasia patients were collected and processed to generate whole-blood and serum samples. Three different rapid two-site immunoassays were developed to measure the concentrations of total PSA (PSA-T), free PSA (PSA-F), and PSA-α1-antichymotrypsin complex (PSA-ACT) to detect in vitro changes in whole-blood samples immediately after venipuncture. The possible influence of muscle movement on the release of PSA from prostate gland was studied in healthy men by measuring the rapid in vitro whole-blood kinetics of PSA forms before and after 15 min of physical exercise on a stationary bicycle.Results: Rapid PSA-T, PSA-F, and PSA-ACT assays were designed using a 10-min sample incubation. No significant changes were detected in the concentrations of PSA-T, PSA-F, and PSA-ACT from the earliest time point of 12–16 min compared with measurements performed up to 4 h after venipuncture. Physical exercise did not influence the concentrations of the circulating forms of PSA. Hematocrit-corrected whole-blood values of PSA-T and PSA-F forms were comparable to the respective serum values. Calculation of the percentage of PSA-F (PSA F/T ratio × 100) was similar irrespective of the sample format used, i.e., whole blood or serum.Conclusions: We found that immunodetectable PSA forms are likely at steady state immediately after venipuncture, thus enabling the use of anticoagulated whole-blood samples in near-patient settings for point-of-care testing, whereas determinations of PSA (e.g., PSA-T, PSA-F, or PSA-ACT) performed within the time frame of the office visit would provide results equivalent to conventional analyses performed in serum.
Enzymatic Mutation Detection Method Evaluated for Detection of p53 Mutations in cDNA from Breast Cancers
Authors: Norberg Torbjörn , Klaar Sigrid , Lindqvist Lena , Lindahl Thomas , Ahlgren Johan , Bergh Jonas 
Published: January 2020

Abstract
Background: Rapid, reproducible, and easily run methods with high sensitivity and specificity are required for mutation screening of clinical samples. We evaluated the Enzymatic Mutation Detection (EMDTM) method by analysis of archival cDNA from 203 breast cancer patients and comparison with results of cDNA-based sequencing of the tumor suppressor gene p53.
Methods: The EMD technology uses the T4 endonuclease VII, which cleaves double-stranded DNA at sites where a DNA mismatch is present because of mispairing or an insertion/deletion of nucleotides. The EMD analyses were carried out by dividing the p53 gene into two overlapping fragments that were analyzed separately. After PCR amplification, the fragments were hybridized with wild-type p53 and subsequently exposed to the EMD enzyme. Cleavage products were analyzed and scored using an ALFTM automated DNA sequencer and ALFwin Fragment Analyzer software (Ver. 1.02).
Results: The EMD technique had sensitivities of 45% and 64% and specificities of 83% and 84% for the two fragments, respectively. Patients with EMD-positive, wild-type p53 tumors had a survival similar to that of patients with EMD-negative, wild-type p53 tumors. Node-positive patients with p53 mutated tumors according to sequencing had a statistically significantly worse overall survival than those with p53 wild-type tumors (P = 0.016), whereas this difference in survival was not detected when p53 status was determined with EMD (P = 0.47).
Conclusions: EMD had insufficient sensitivity for consideration in screening for the p53 gene in this archival material. Sequencing must still be considered as the standard procedure.
New Polymorphic Short Tandem Repeats for PCR-based Charcot-Marie-Tooth Disease Type 1A Duplication Diagnosis
Authors: Badano Jose L , Inoue Ken , Katsanis Nicholas , Lupski James R 
Published: January 2020

Abstract
Background: Charcot-Marie-Tooth disease type 1A (CMT1A) accounts for 70–90% of cases of CMT1 and is most frequently caused by the tandem duplication of a 1.4-Mb genomic fragment on chromosome 17p12. Molecular diagnosis of CMT1A has been based primarily on pulsed-field electrophoresis, fluorescence in situ hybridization, polymorphic allele dosage analysis, and quantitative PCR. We sought to improve the fidelity and applicability of PCR-based diagnosis by developing a panel of novel, highly polymorphic short tandem repeats (STRs) from within the CMT1A duplicated region.
Methods: We used a recently available genomic sequence to identify potentially polymorphic simple repeats. We then amplified these sequences in a multiethnic cohort of unaffected individuals and assessed the heterozygosity and number of alleles for each STR. Highly informative markers were then tested in a set of previously diagnosed CMT1A duplication patients, and the ability to identify the genomic duplication through the presence of three bands was assessed.
Results: We identified 34 polymorphic markers, 15 of which were suitable for CMT1A diagnosis on the basis of high heterozygosity in different ethnic groups, peak uniformity, and a large number of alleles. On the basis of the fluorescent dye and allele range of each marker, we developed two panels, each of which could be analyzed concurrently. Panel 1, which comprised 10 markers, detected 37 of 39 duplications, whereas panel 2, which comprised the remaining 5 markers, identified 21 of 39 duplications. Through the combination of both panels, we identified 39 of 39 duplications in previously diagnosed CMT1A patients.
Conclusions: The newly developed 15-marker set has the capability of detecting &gt;99% of duplications and thus is a powerful and versatile diagnostic tool.
C-Reactive Protein Concentrations and Angiographic Characteristics of Coronary Lesions
Authors: Katritsis Demosthenes , Korovesis Socrates , Giazitzoglou Eleftherios , Parissis John , Kalivas Pericles , Webb-Peploe Michael M , Ioannidis John P A , Haliassos Alexander 
Published: January 2020

Abstract
Background: C-Reactive protein (CRP) is a strong predictor of clinical outcome in coronary artery disease (CAD), and inflammation has been implicated in the process. We aimed to evaluate whether CRP concentrations measured with a new, automated particle-enhanced immunoturbidimetric method for high-sensitivity CRP may be related to specific high-risk angiographic features of coronary lesions.
Methods: In a cross-sectional study, we examined 103 consecutive patients undergoing cardiac catheterization for suspected CAD. We assessed the association of preprocedural CRP concentrations with clinical presentation (unstable angina) and angiographic features of coronary lesions.
Results: Twenty patients had unstable angina. Independent predictors of unstable angina included increased CRP [odds ratio (OR), 2.93 per 10-fold increase in CRP; 95% confidence interval (CI), 1.28–6.69; P = 0.01] and the presence of macroscopic thrombus (OR, 7.08; 95% CI, 1.33–37.8; P = 0.02). Thirty-two culprit lesions had macroscopic thrombus or eccentric/irregular discrete morphology without total occlusion. Increased CRP was the strongest predictor of such features (OR, 2.04 per 10-fold increase in CRP; 95% CI, 1.03–4.04; P = 0.04), and the effect was independent of the presence of unstable angina.
Conclusions: Among patients with suspected CAD undergoing coronary angiography, increased CRP is strongly associated with unstable angina and with specific high-risk features of the culprit coronary lesions.
Glucuronidation of Prodrug Reactive Site: Isolation and Characterization of Oxymethylglucuronide Metabolite of Fosphenytoin
Authors: Annesley Thomas M , Kurzyniec Stephen , Nordblom Gerald D , Buchanan Nathan , Pool William , Reily Michael , Talaat Rasmy , Roberts William L 
Published: January 2020

Abstract
Background: This investigation was undertaken to identify the structure of a novel immunoreactive metabolite derived from fosphenytoin that has been hypothesized previously as present in sera from renally impaired patients receiving this prodrug.
Methods: The metabolite was isolated from uremic sera using solid-phase extraction and HPLC. Structural analysis was performed using HPLC–tandem mass spectrometry, nuclear magnetic resonance (NMR), deuterium exchange, and chemical derivatization. Immunoreactivity was evaluated using a fluorescence polarization immunoassay.
Results: The metabolite had a parent ion at m/z 457 in the negative-ion mode and fragmented to yield the m/z 251 of phenytoin, as well as other mass fragments of phenytoin. Mass fragments associated with glucuronic acid were also present. The chromatographic peak corresponding to this metabolite demonstrated immunoreactivity sufficient to lead to falsely increased reported values for phenytoin immunoassays. The observed immunoreactivity was also proportional to the relative concentration of the metabolite in collected fractions. Analysis by NMR indicated the presence of phenyl groups with chemical shifts identical to those of phenytoin, as well as the presence of a methylene bridge, which was consistent with the same methylene bridge present on the phosphate ester of fosphenytoin. Comparative analysis of serum samples from renally impaired patients receiving phenytoin vs fosphenytoin using multiple reaction monitoring quantification demonstrated that this metabolite was associated with fosphenytoin administration.
Conclusions: A unique immunoreactive oxymethylglucuronide metabolite derived from fosphenytoin has been isolated from sera from uremic patients receiving this prodrug.
Examination of Postmortem Fluids and Tissues for the Presence of Methylecgonidine, Ecgonidine, Cocaine, and Benzoylecgonine Using Solid-Phase Extraction and Gas Chromatography–Mass Spectrometry2
Authors: Shimomura Eric T , Hodge Gwendolyn D , Paul Buddha D 
Published: January 2020

AbstractBackground: During the smoking of crack cocaine (COC), methyl ecgonidine (MED) is formed as one of the pyrolysis products. Once in the body, MED is converted to ecgonidine (ED) through several processes that include spontaneous hydrolysis and enzymatic hydrolysis. The presence of MED and/or ED could provide valuable information to help determine antemortem conditions in cases where COC is involved. Our goal was to examine postmortem tissues and fluids for the presence of MED, ED, COC, and benzoylecgonine (BZ).Methods: Liver, brain, blood, and urine specimens obtained from 15 postmortem cases were extracted using solid-phase extraction, derivatized, and analyzed using gas chromatography–mass spectrometry with selective-ion monitoring.Results: Median concentrations (range) of drugs observed in postmortem liver, brain, blood, and urine were 0 (0–10) ng/g, 7 (0–92) ng/g, 0 (0–42) μg/L, and 62 (0–2030) μg/L, respectively, for MED; 655 (90–3274) ng/g, 22 (0–52) ng/g, 119 (13–773) μg/L, and 456 (109–7452) μg/L, respectively, for ED; 57 (0–503) ng/g, 187 (0–1403) ng/g, 12 (0–88) μg/L, and 1208 (37–28 062) μg/L, respectively, for COC; and 821 (45–4980) ng/g, 524 (46–5153) ng/g, 458 (30–2071) μg/L, and 6768 (917–116 430) μg/L, respectively, for BZ. MED was detected in 12 of 15 postmortem cases. The concentrations were highest in urine compared with liver, brain, and blood. The hydrolysis product ED was detected in all postmortem cases, and the concentrations were substantially higher than MED in all liver, blood, and urine specimens.Conclusion: ED may be a more useful indicator of crack COC smoking.
No Influence of the MDR-1 C3435T Polymorphism or a CYP3A4 Promoter Polymorphism (CYP3A4-V Allele) on Dose-adjusted Cyclosporin A Trough Concentrations or Rejection Incidence in Stable Renal Transplant Recipients
Authors: von Ahsen Nicolas , Richter Michael , Grupp Clemens , Ringe Burckhardt , Oellerich Michael , Armstrong Victor W 
Published: January 2020

AbstractBackground: A substantial proportion of the variability in the absorption and clearance of cyclosporin A (CsA) after oral administration has been attributed to variability in liver cytochrome P-450 3A4 (CYP3A4) activity and intestinal P-glycoprotein (P-gp) concentration. A polymorphism in the CYP3A4 promoter region, termed “variant” allele CYP3A4-V, was postulated to be associated with altered CYP3A4 enzyme activity. A polymorphism in exon 26 (C3435T) of the multidrug resistance-1 (MDR-1) gene was correlated with intestinal expression and in vivo activity of P-gp.Methods: We investigated the occurrence of both polymorphisms in 124 stable Caucasian renal transplant recipients (&gt;6 months after transplantation) on CsA as the primary immunosuppressant. Real-time, rapid-cycle PCR methods were developed and used for genotyping.Results: The estimated allele frequencies for the MDR-1 C3435T allele (54%) and the CYP3A4-V allele (4.8%) were similar to those reported for Caucasian populations. No significant differences were found for the CsA doses needed to maintain similar CsA trough concentrations in patients with and without the CYP3A4-V allele or in patients with different MDR-1 C3435T genotypes. Furthermore, neither of the polymorphisms investigated was associated with renal function as assessed by creatinine plasma concentration or, in a retrospective analysis, the incidence of acute rejection.Conclusions: These findings suggest that the MDR-1 C3435T mutation and the CYP3A4-V variant are not major determinants of CsA efficacy in renal transplant recipients.
Emerging Homogeneous DNA-based Technologies in the Clinical Laboratory
Authors: Foy Carole A , Parkes Helen C 
Published: January 2020

AbstractBackground: Advances in molecular diagnostic technologies have enabled genetic testing in single closed-tube reactions. The purpose of this review is to highlight some of the platforms and technologies currently available for the homogeneous detection of targets and the application of the technologies in the clinical setting. Validation issues surrounding the technologies, which may need to be addressed before they can become widely accepted, will also be discussed.Approach: This review discusses the principles of several of the major technologies available for performing homogeneous genetic analyses. Publications arising from the application of the technologies in a wide range of clinical areas are used to highlight and compare the potential advantages and shortcomings of the various technologies.Content: This review is descriptive and focuses on three areas: the technologies available for performing homogeneous analysis, the clinical applications where the technologies are being used, and validation issues surrounding the acceptance of the technologies in the general clinical setting.Summary: This review intends to give the reader a greater understanding of the various technologies available for performing homogeneous genetic testing in the clinical laboratory. Through insight into the principles and performance characteristics underlying these technologies, the end user can evaluate their value and limitations in the clinical diagnostic setting.