23,754 results match your criteria Clinical Chemistry[Journal]


Detection and Quantification of Carbohydrate-Deficient Transferrin by MALDI-Compatible Protein Chips Prepared by Ambient Ion Soft Landing.

Clin Chem 2018 Jul 12. Epub 2018 Jul 12.

Institute of Microbiology, v.v.i., Czech Academy of Sciences, Prague, Czech Republic

Background: Transferrin is synthetized in the liver and is the most important iron-transport carrier in the human body. Severe alcohol consumption leads to alterations in glycosylation of transferrin. Mass spectrometry can provide fast detection and quantification of transferrin isoforms because they have different molecular masses. Read More

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Genomic Privacy.

Clin Chem 2018 Jul 10. Epub 2018 Jul 10.

Department of Pathology, at University of Texas Southwestern Medical Center and Children's Health, Dallas, TX

Background: Genetic information is unique among all laboratory data because it not only informs the current health of the specific person tested but may also be predictive of the future health of the individual and, to varying degrees, all biological relatives.

Content: As DNA sequencing has become ubiquitous with decreasing cost, large repositories of genomic data have emerged from the domains of research, healthcare, law enforcement, international security, and recreational consumer interest (i.e. Read More

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July 2018
3 Reads

Fecal Microbiota and Screening for Colorectal Cancer.

Clin Chem 2018 Jul 10. Epub 2018 Jul 10.

Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY.

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Cardiac Troponin T Concentrations, Reversible Myocardial Ischemia, and Indices of Left Ventricular Remodeling in Patients with Suspected Stable Angina Pectoris: a DOPPLER-CIP Substudy.

Clin Chem 2018 Jun 29. Epub 2018 Jun 29.

Division of Medicine, Akershus University Hospital, Lørenskog, Norway and Center for Heart Failure Research, University of Oslo, Oslo, Norway;

Background: Cardiac troponin T concentrations measured with high-sensitivity assays (hs-cTnT) provide important prognostic information for patients with stable coronary artery disease (CAD). However, whether hs-cTnT concentrations mainly reflect left ventricular (LV) remodeling or recurrent myocardial ischemia in this population is not known.

Methods: We measured hs-cTnT concentrations in 619 subjects with suspected stable CAD in a prospectively designed multicenter study. Read More

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June 2018
1 Read

, or the Letter "Aleph" with 22 Flowers.

Authors:
Ross T Barnard

Clin Chem 2018 Jul;64(7):1130

School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.

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Negative Anion Gap in a Teenager with Epilepsy.

Clin Chem 2018 Jul;64(7):1127-1128

Department of Laboratory Medicine, Hospital Universitari Son Espases, Palma, Balearic Islands, Spain;

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Commentary.

Authors:
Leon D Sanchez

Clin Chem 2018 Jul;64(7):1005

Harvard Medical School, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA.

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Commentary.

Authors:
James H Nichols

Clin Chem 2018 Jul;64(7):1004-1005

Vanderbilt University Medical Center, Nashville, TN.

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Fill in the Gaps: An Unresponsive 55-Year-Old Man.

Clin Chem 2018 Jul;64(7):1001-1004

Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO.

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Specifying a Gold Standard for the Validation of Fetal Fraction Estimation in Prenatal Screening.

Clin Chem 2018 Jun 26. Epub 2018 Jun 26.

Wolfson Institute of Preventive Medicine, Barts, and the London School of Medicine and Dentistry, Queen Mary University London, London, UK.

Background: An estimate of fetal fraction (FF) is needed for DNA-based screening for trisomy 21 and other aneuploidies, but there is no gold standard to validate FF measurement methods. We specify a gold standard and use it to validate 1 method of measuring FF (SeqFF).

Methods: The gold standard was a formula derived from 2 elements: () an estimate of the percentage of DNA fragments in maternal plasma from chromosome 21 (%Ch21) in pregnancies without trisomy 21, 18, or 13 (P) and () calculation of %Ch21 with increasing FF in trisomy 21 pregnancies (P). Read More

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June 2018
1 Read

Dietary Intakes and Circulating Concentrations of Branched-Chain Amino Acids in Relation to Incident Type 2 Diabetes Risk Among High-Risk Women with a History of Gestational Diabetes Mellitus.

Clin Chem 2018 Jun 26. Epub 2018 Jun 26.

Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.

Background: Circulating branched-chain amino acids (BCAAs; isoleucine, leucine, valine) are consistently associated with increased type 2 diabetes (T2D) risk, but the relationship with dietary intake of BCAAs is less clear.

Methods: The longitudinal Nurses' Health Study II cohort conducted a blood collection from 1996 to 1999. We profiled plasma metabolites among 172 incident T2D cases and 175 age-matched controls from women reporting a history of gestational diabetes before blood draw. Read More

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June 2018
1 Read

The EuBIVAS: Within- and Between-Subject Biological Variation Data for Electrolytes, Lipids, Urea, Uric Acid, Total Protein, Total Bilirubin, Direct Bilirubin, and Glucose.

Clin Chem 2018 Jun 25. Epub 2018 Jun 25.

Working Group on Biological Variation, European Federation of Clinical Chemistry and Laboratory Medicine, Milan, Italy.

Background: The European Federation of Clinical Chemistry and Laboratory Medicine European Biological Variation Study (EuBIVAS) has been established to deliver rigorously determined data describing biological variation (BV) of clinically important measurands. Here, EuBIVAS-based BV estimates of serum electrolytes, lipids, urea, uric acid, total protein, total bilirubin, direct bilirubin, and glucose, as well as their associated analytical performance specifications (APSs), are presented.

Method: Samples were drawn from 91 healthy individuals (38 male, 53 female; age range, 21-69 years) for 10 consecutive weeks at 6 European laboratories. Read More

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June 2018
3 Reads

The Inadvertent Discovery of Human Fetal Cell Microchimerism.

Authors:
Diana W Bianchi

Clin Chem 2018 Jun 25. Epub 2018 Jun 25.

Section on Prenatal Genomics and Fetal Therapy, Medical Genetics Branch, National Human Genome Institute, National Institutes of Health, Bethesda, MD.

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Clinical Validation of a Novel High-Sensitivity Cardiac Troponin I Assay for Early Diagnosis of Acute Myocardial Infarction.

Clin Chem 2018 Jun 25. Epub 2018 Jun 25.

Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Hospital Basel, University of Basel, Basel, Switzerland

Background: Clinical performance of the novel high-sensitivity cardiac troponin I (Siemens-hs-cTnI-Centaur) assay is unknown. We aimed to clinically validate the Siemens-hs-cTnI-Centaur assay and develop 0/1-h and 0/2-h algorithms.

Methods: We enrolled patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI). Read More

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June 2018
4 Reads

Genome-Wide Analysis of Circulating Cell-Free DNA Copy Number Detects Active Melanoma and Predicts Survival.

Clin Chem 2018 Jun 25. Epub 2018 Jun 25.

Academic Unit of Molecular Oncology, Sheffield Medical School, University of Sheffield, Sheffield, S10 2RX, UK.

Background: A substantial number of melanoma patients develop local or metastatic recurrence, and early detection of these is vital to maximize benefit from new therapies such as immune checkpoints or inhibitors of BRAF and MEK. This study explored the use of novel DNA copy-number profiles in circulating cell-free DNA (cfDNA) as a potential biomarker of active disease and survival.

Patients And Methods: Melanoma patients were recruited from oncology and dermatology clinics in Sheffield, UK, and cfDNA was isolated from stored blood plasma. Read More

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June 2018
2 Reads

Pharmacogenetics of Warfarin Therapy.

Authors:
Christian T Ruff

Clin Chem 2018 Jun 25. Epub 2018 Jun 25.

TIMI Study Group, Cardiovascular Medicine Division, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.

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June 2018
1 Read

High-Sensitivity Cardiac Troponin-Based Strategies for the Assessment of Chest Pain Patients-A Review of Validation and Clinical Implementation Studies.

Clin Chem 2018 Jun 25. Epub 2018 Jun 25.

Department of Medical Sciences and Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden.

Background: The introduction of high-sensitivity cardiac troponin (hs-cTn) assays has improved the early assessment of chest pain patients. A number of hs-cTn-based algorithms and accelerated diagnostic protocols (ADPs) have been developed and tested subsequently. In this review, we summarize the data on the performance and clinical utility of these strategies. Read More

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June 2018
1 Read

Preanalytical Processing and Biobanking Procedures of Biological Samples for Metabolomics Research: A White Paper, Community Perspective (for "Precision Medicine and Pharmacometabolomics Task Group"-The Metabolomics Society Initiative).

Clin Chem 2018 Jun 19. Epub 2018 Jun 19.

Metabolomics Unit, Institute for Molecular Medicine FIMM, HiLIFE, University of Helsinki, Helsinki, Finland.

Background: The metabolome of any given biological system contains a diverse range of low molecular weight molecules (metabolites), whose abundances can be affected by the timing and method of sample collection, storage, and handling. Thus, it is necessary to consider the requirements for preanalytical processes and biobanking in metabolomics research. Poor practice can create bias and have deleterious effects on the robustness and reproducibility of acquired data. Read More

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Toward a Global Overview of HbA1c Test Performance.

Clin Chem 2018 Jun 19. Epub 2018 Jun 19.

Department of Pathology, Sidra Medicine and Weill Cornell Medicine, Doha, Qatar.

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EurA1c: the European HbA1c Trial to Investigate the Performance of HbA1c Assays in 2166 Laboratories across 17 Countries and 24 Manufacturers by Use of the IFCC Model for Quality Targets.

Authors:

Clin Chem 2018 Jun 19. Epub 2018 Jun 19.

Background: A major objective of the IFCC Committee on Education and Use of Biomarkers in Diabetes is to generate awareness and improvement of HbA1c assays through evaluation of the performance by countries and manufacturers.

Methods: Fresh whole blood and lyophilized hemolysate specimens manufactured from the same pool were used by 17 external quality assessment organizers to evaluate analytical performance of 2166 laboratories. Results were evaluated per country, per manufacturer, and per manufacturer and country combined according to criteria of the IFCC model for quality targets. Read More

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A Simple and Novel Fecal Biomarker for Colorectal Cancer: Ratio of to Probiotics Populations, Based on Their Antagonistic Effect.

Clin Chem 2018 Jun 18. Epub 2018 Jun 18.

Department of Microbial and Biochemical Pharmacy, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China;

Background: Gut microbial dysbiosis contributes to the development of colorectal cancer (CRC). We evaluated the utility of fecal bacterial biomarker candidates identified by our 16S rDNA sequencing analysis for CRC diagnosis.

Methods: We measured the relative abundance of (), (), (), and () by quantitative PCR in fecal samples from 2 cohorts of 903 individuals. Read More

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Study Design and qPCR Data Analysis Guidelines for Reliable Circulating miRNA Biomarker Experiments: A Review.

Clin Chem 2018 Jun 14. Epub 2018 Jun 14.

Departments of Vascular Medicine

Background: In the past decade, the search for circulating microRNA (miRNA) biomarkers has yielded numerous associations between miRNAs and different types of disease. However, many of these relations could not be replicated in subsequent studies under similar experimental conditions. Although this lack of replicability may be explained by the variation in experimental design and analysis methods, guidelines on the most appropriate design and analysis methods to study circulating miRNAs are scarce. Read More

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A Step Closer to Cancer Screening by Blood Test.

Authors:
Alain R Thierry

Clin Chem 2018 Jun 14. Epub 2018 Jun 14.

IRCM, Institut de Recherche en Canceérologie de Montpellier, Montpellier, France;

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Assessment of Digital PCR as a Primary Reference Measurement Procedure to Support Advances in Precision Medicine.

Clin Chem 2018 Jun 14. Epub 2018 Jun 14.

Molecular and Cell Biology Team, LGC, Teddington, Middlesex, UK;

Background: Genetic testing of tumor tissue and circulating cell-free DNA for somatic variants guides patient treatment of many cancers. Such measurements will be fundamental in the future support of precision medicine. However, there are currently no primary reference measurement procedures available for nucleic acid quantification that would support translation of tests for circulating tumor DNA into routine use. Read More

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June 2018
2 Reads

Commutability Assessment of Candidate Reference Materials for Pancreatic α-Amylase.

Clin Chem 2018 Jun 14. Epub 2018 Jun 14.

Clinical Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.

Background: Measurement standardization of the catalytic concentration of α-amylase in serum is based on 3 pillars: the primary reference measurement procedure (PRMP), reference laboratories, and suitable certified reference materials (CRMs). Commutability is a prerequisite when using a CRM for calibration and trueness control of routine methods or for value transfer from the PRMP to end-user calibrators of routine methods through a calibration hierarchy.

Methods: We performed a commutability study with 30 serum pools and 5 candidate reference materials (RMs) for pancreatic α-amylase using an automated version of the PRMP and 5 different routine methods. Read More

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June 2018
3 Reads

Liver- and Colon-Specific DNA Methylation Markers in Plasma for Investigation of Colorectal Cancers With or Without Liver Metastases.

Clin Chem 2018 Jun 14. Epub 2018 Jun 14.

Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China;

Background: Measurement of DNA derived from different tissues in the circulating DNA pool can provide important information regarding the presence of many pathological conditions. However, existing methods involving genome-wide bisulfite sequencing are relatively expensive and may present challenges for large-scale analysis.

Methods: Through identifying differentially methylated regions in the liver and colon compared with other tissues, we identified 2 markers and developed corresponding droplet digital PCR assays. Read More

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Adapting an Established Clinical Chemistry Quality Control Measure for Droplet Generation Performance in Digital PCR.

Clin Chem 2018 06 11. Epub 2018 Jun 11.

Translational Genomics andEpigenomics LaboratoryOlivia Newton-John Cancer ResearchInstitute Heidelberg, Victoria, Australia

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Current and Emerging Trends in Point-of-Care Technology and Strategies for Clinical Validation and Implementation.

Clin Chem 2018 Jun 8. Epub 2018 Jun 8.

William Pepper Laboratory, University of Pennsylvania Heath System, and the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.

Background: Point-of-care technology (POCT) provides actionable information at the site of care to allow rapid clinical decision-making. With healthcare emphasis shifting toward precision medicine, population health, and chronic disease management, the potential impact of POCT continues to grow, and several prominent POCT trends have emerged or strengthened in the last decade.

Content: This review summarizes current and emerging trends in POCT, including technologies approved or cleared by the Food and Drug Administration or in development. Read More

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June 2018
9 Reads

Association of Tryptophan Metabolites with Incident Type 2 Diabetes in the PREDIMED Trial: A Case-Cohort Study.

Clin Chem 2018 Jun 8. Epub 2018 Jun 8.

Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Rovira i Virgili University, Reus, Spain;

Background: Metabolites of the tryptophan-kynurenine pathway (i.e., tryptophan, kynurenine, kynurenic acid, quinolinic acid, 3-hydroxyanthranilic) may be associated with diabetes development. Read More

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June 2018
5 Reads

Clinical Assay for AFP-L3 by Using Multiple Reaction Monitoring-Mass Spectrometry for Diagnosing Hepatocellular Carcinoma.

Clin Chem 2018 Jun 6. Epub 2018 Jun 6.

Department of Biomedical Engineering;

Background: agglutinin-reactive fraction of α-fetoprotein (AFP-L3) is a serum biomarker for hepatocellular carcinoma (HCC). AFP-L3 is typically measured by liquid-phase binding assay (LiBA). However, LiBA does not always reflect AFP-L3 concentrations because of its low analytical sensitivity. Read More

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June 2018
1 Read

Essential Diagnostics for the Use of World Health Organization Essential Medicines.

Clin Chem 2018 Jun 5. Epub 2018 Jun 5.

Department of Pathology and Laboratory Medicine, Johns Hopkins University, Baltimore, MD.

Background: There are numerous barriers to achieving high-quality laboratory diagnostic testing in resource-limited countries. These include inconsistent supply chains, variable quality of diagnostic devices, lack of human and financial resources, the ever-growing list of available tests, and a historical reliance on syndromic treatment algorithms. A list of essential diagnostics based on an accepted standard like the WHO Essential Medicines List (EML) could coordinate stakeholders in the strengthening of laboratory capacity globally. Read More

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In Reply.

Clin Chem 2018 May 30. Epub 2018 May 30.

Mayo Clinic, Rochester, MN

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Urinary Steroid Profiling in the Diagnosis of Adrenal Disorders.

Authors:
John W Honour

Clin Chem 2018 May 30. Epub 2018 May 30.

Institute for Women's HealthUniversity College LondonHuntley St., London, UK

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Sex-Specific Versus Overall Clinical Decision Limits for Cardiac Troponin I and T for the Diagnosis of Acute Myocardial Infarction: A Systematic Review.

Clin Chem 2018 Jul 29;64(7):1034-1043. Epub 2018 May 29.

Department of Central Diagnostic Laboratory, Clinical Chemistry, Maastricht University Medical Center, Maastricht, the Netherlands;

Background: The overall clinical decision limits of high-sensitivity cardiac troponin I (hs-cTnI; 26 ng/L) and T (hs-cTnT; 14 ng/L) may contribute to underdiagnosis of acute myocardial infarction in women. We performed a systematic review to investigate sex-specific and overall 99th percentiles of hs-cTnI and hs-cTnT derived from healthy reference populations.

Content: We searched in PubMed and EMBASE for original studies, and by screening reference lists. Read More

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"Quiet Waters".

Authors:
Amy Pyle-Eilola

Clin Chem 2018 Jun;64(6):987

Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus OH.

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A 69-Year-Old Woman with Markedly Decreased Cholesterol.

Clin Chem 2018 Jun;64(6):982-983

Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO.

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Waiting for Severe Hyperbilirubinemia.

Clin Chem 2018 Jun;64(6):981

Servicio de Análisis Clínicos, Complejo Hospitalario de Navarra, Pamplona, Spain.

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Argininemia, Hyperornithinemia, and 3-Hydroxyisovaleric Aciduria.

Clin Chem 2018 Jun;64(6):978-980

Department of Clinical Biochemistry, Rambam Health Care Campus, Haifa, Israel;

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Commentary.

Authors:
Ravinder J Singh

Clin Chem 2018 Jun;64(6):897

Mayo Clinic, Rochester, MN.

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Commentary.

Authors:
Abby Hollander

Clin Chem 2018 Jun;64(6):896

Washington University in St. Louis, St. Louis Children's Hospital, St. Louis, MO.

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A Teenage Girl with Unexpected Pubertal Changes.

Clin Chem 2018 Jun;64(6):892-896

Department of Biochemistry, Dorevitch Pathology, Heidelberg, Victoria, Australia.

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June 2018
1 Read

Genetic Screening Test to Detect Translocations in Acute Leukemias by Use of Targeted Locus Amplification.

Clin Chem 2018 Jul 24;64(7):1096-1103. Epub 2018 May 24.

University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, the Netherlands.

Background: Over 500 translocations have been identified in acute leukemia. To detect them, most diagnostic laboratories use karyotyping, fluorescent in situ hybridization, and reverse transcription PCR. Targeted locus amplification (TLA), a technique using next-generation sequencing, now allows detection of the translocation partner of a specific gene, regardless of its chromosomal origin. Read More

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July 2018
2 Reads

Activity-Based Concept to Screen Biological Matrices for Opiates and (Synthetic) Opioids.

Clin Chem 2018 May 18. Epub 2018 May 18.

Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium;

Background: Detection of new highly potent synthetic opioids is challenging as new compounds enter the market. Here we present a novel screening method for the detection of opiates and (synthetic) opioids based on their activity.

Methods: A cell-based system was set up in which activation of the μ -opioid receptor (MOR) led to recruitment of β-arrestin 2, resulting in functional complementation of a split NanoLuc luciferase and allowing readout via bioluminescence. Read More

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Experimental Design, Randomization, and Validation.

Authors:
Keith Baggerly

Clin Chem 2018 May 18. Epub 2018 May 18.

MD Anderson Cancer Center, Houston, TX.

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RNA Profiles of Circulating Tumor Cells and Extracellular Vesicles for Therapy Stratification of Metastatic Breast Cancer Patients.

Clin Chem 2018 Jul 16;64(7):1054-1062. Epub 2018 May 16.

Department of Gynecology and Obstetrics, University Hospital of Essen, Germany.

Background: Liquid biopsies are discussed to provide surrogate markers for therapy stratification and monitoring. We compared messenger RNA (mRNA) profiles of circulating tumor cells (CTCs) and extracellular vesicles (EVs) in patients with metastatic breast cancer (MBC) to estimate their utility in therapy management.

Methods: Blood was collected from 35 hormone receptor-positive/HER2-negative patients with MBC at the time of disease progression and at 2 consecutive staging time points. Read More

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July 2018
1 Read