scholarly journals Evaluation of four different HPLC devices for hemoglobinopathy screening

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Müjgan Ercan Karadağ ◽  
Emiş Deniz Akbulut ◽  
Esin Avcı ◽  
Esra Fırat Oğuz ◽  
Saadet Kader ◽  
...  
Keyword(s):  
Gold Standard ◽  
High Performance ◽  
Public Health Problem ◽  
Reference Value ◽  
Comparison Study ◽  
Gold Standard Method ◽  
Blood Samples ◽  
Systematic Biases ◽  
Hemoglobin Variants ◽  
Thalassemia Screening

AbstractObjectiveHemoglobinopathies are a common public health problem in Turkey. In the screening of these disorders in population, cation-exchange high performance liquid chromatography (HPLC) is accepted as the gold standard method. In this study, the aim was to assess four different HPLC devices used in hemoglobinopathy screening.Materials and methodsA total of 58 blood samples were analyzed with four different HPLC methods (Bio-Rad variant II, Agilent 1100, Tosoh G8 and Trinity Ultra2 trademarks).ResultsThe comparison study demonstrated a good correlation between the results of each HPLC analyzer and the reference value obtained by averaging all the HbA2 results belonging to the methods tested in the study [ (Tosoh G8 (r=0.988), Bio-Rad variant II (r=0.993), Agilent 1100 (r=0.98) and Trinity Ultra2 (r=0.992) ]. HbA2 determination in the presence of HbE was interfered in both Bio-Rad variant II and Tosoh G8.ConclusionThe analyzers were found to have compatible HbA2 results but with accompanying different degrees of proportional and systematic biases. HPLC analyzers may be affected by different hemoglobin variants at different HbA2 concentrations, which is an important point to take into consideration during the evaluation of HbA2 results in thalassemia screening.

scholarly journals Determination of 19 Psychoactive Substances in Premortem and Postmortem Whole Blood Samples Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 78
Author(s):  
Sevasti Karampela ◽  
Jessica Smith ◽  
Irene Panderi
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Formic Acid ◽  
Whole Blood ◽  
High Performance ◽  
Tandem Mass ◽  
Psychoactive Substances ◽  
Blood Samples ◽  
Whole Blood Samples

An ever-increasing need exists within the forensic laboratories to develop analytical processes for the qualitative and quantitative determination of a broad spectrum of new psychoactive substances. Phenylethylamine derivatives are among the major classes of psychoactive substances available on the global market and include both amphetamine analogues and synthetic cathinones. In this work, an ultra-high-performance liquid chromatography-positive ion electrospray ionization tandem mass spectrometric method (UHPLC-ESI-MS/MS) has been developed and fully validated for the determination of 19 psychoactive substances, including nine amphetamine-type stimulants and 10 synthetic cathinone derivatives, in premortem and postmortem whole blood. The assay was based on the use of 1 mL premortem or postmortem whole blood, following solid phase extraction prior to the analysis. The separation was achieved on a Poroshell 120 EC-C18 analytical column with a gradient mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water in 9 min. The dynamic multiple reaction monitoring used in this work allowed for limit of detection (LOD) and lower limit of quantitation (LOQ) values of 0.5 and 2 ng mL−1, respectively, for all analytes both in premortem and postmortem whole blood samples. A quadratic calibration model was used for the 12 quantitative analytes over the concentration range of 20–2000 ng mL−1, and the method was shown to be precise and accurate both in premortem and postmortem whole blood. The method was applied to the analysis of real cases and proved to be a valuable tool in forensic and clinical toxicology.

scholarly journals Quantum chemical benchmark databases of gold-standard dimer interaction energies

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Alexander G. Donchev ◽  
Andrew G. Taube ◽  
Elizabeth Decolvenaere ◽  
Cory Hargus ◽  
Robert T. McGibbon ◽  
...  
Keyword(s):  
Machine Learning ◽  
Gold Standard ◽  
Training Data ◽  
Structure Theory ◽  
Cluster Method ◽  
Coupled Cluster ◽  
Interaction Energies ◽  
Gold Standard Method ◽  
Representative Subset ◽  
Semi Empirical

AbstractAdvances in computational chemistry create an ongoing need for larger and higher-quality datasets that characterize noncovalent molecular interactions. We present three benchmark collections of quantum mechanical data, covering approximately 3,700 distinct types of interacting molecule pairs. The first collection, which we refer to as DES370K, contains interaction energies for more than 370,000 dimer geometries. These were computed using the coupled-cluster method with single, double, and perturbative triple excitations [CCSD(T)], which is widely regarded as the gold-standard method in electronic structure theory. Our second benchmark collection, a core representative subset of DES370K called DES15K, is intended for more computationally demanding applications of the data. Finally, DES5M, our third collection, comprises interaction energies for nearly 5,000,000 dimer geometries; these were calculated using SNS-MP2, a machine learning approach that provides results with accuracy comparable to that of our coupled-cluster training data. These datasets may prove useful in the development of density functionals, empirically corrected wavefunction-based approaches, semi-empirical methods, force fields, and models trained using machine learning methods.

scholarly journals Performance of Seven Consumer Sleep-Tracking Devices Compared with Polysomnography

SLEEP ◽  
2020 ◽  
Author(s):  
Evan D Chinoy ◽  
Joseph A Cuellar ◽  
Kirbie E Huwa ◽  
Jason T Jameson ◽  
Catherine H Watson ◽  
...  
Keyword(s):  
Performance Measures ◽  
Gold Standard ◽  
High Performance ◽  
Sleep Stage ◽  
Sleep Laboratory ◽  
Sleep Assessment ◽  
Sleep Condition ◽  
Different Populations ◽  
Tracking Devices ◽  
Better Than

Abstract Study Objectives Consumer sleep-tracking devices are widely used and becoming more technologically advanced, creating strong interest from researchers and clinicians for their possible use as alternatives to standard actigraphy. We therefore tested the performance of many of the latest consumer sleep-tracking devices, alongside actigraphy, versus the gold-standard sleep assessment technique, polysomnography (PSG). Methods In total, 34 healthy young adults (22 women; 28.1 ± 3.9 years, mean ± SD) were tested on three consecutive nights (including a disrupted sleep condition) in a sleep laboratory with PSG, along with actigraphy (Philips Respironics Actiwatch 2) and a subset of consumer sleep-tracking devices. Altogether, four wearable (Fatigue Science Readiband, Fitbit Alta HR, Garmin Fenix 5S, Garmin Vivosmart 3) and three non-wearable (EarlySense Live, ResMed S+, SleepScore Max) devices were tested. Sleep/wake summary and epoch-by-epoch agreement measures were compared with PSG. Results Most devices (Fatigue Science Readiband, Fitbit Alta HR, EarlySense Live, ResMed S+, SleepScore Max) performed as well as or better than actigraphy on sleep/wake performance measures, while the Garmin devices performed worse. Overall, epoch-by-epoch sensitivity was high (all ≥0.93), specificity was low-to-medium (0.18-0.54), sleep stage comparisons were mixed, and devices tended to perform worse on nights with poorer/disrupted sleep. Conclusions Consumer sleep-tracking devices exhibited high performance in detecting sleep, and most performed equivalent to (or better than) actigraphy in detecting wake. Device sleep stage assessments were inconsistent. Findings indicate that many newer sleep-tracking devices demonstrate promising performance for tracking sleep and wake. Devices should be tested in different populations and settings to further examine their wider validity and utility.

Ranitidine as an alcohol dehydrogenase inhibitor in acute methanol toxicity in rats

2009 ◽  
Vol 29 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Amal A El-Bakary ◽  
Sahar A El-Dakrory ◽  
Sohayla M Attalla ◽  
Nawal A Hasanein ◽  
Hala A Malek
Keyword(s):  
Alcohol Dehydrogenase ◽  
High Performance ◽  
Negative Control Group ◽  
Positive Control ◽  
Negative Control ◽  
Control Group ◽  
Sprague Dawley ◽  
Blood Samples ◽  
Methanol Poisoning ◽  
Sprague Dawley Rats

Methanol poisoning is a hazardous intoxication characterized by visual impairment and formic acidemia. The therapy for methanol poisoning is alcohol dehydrogenase (ADH) inhibitors to prevent formate accumulation. Ranitidine has been considered to be an inhibitor of both gastric alcohol and hepatic aldehyde dehydrogenase enzymes. This study aimed at testing ranitidine as an antidote for methanol acute toxicity and comparing it with ethanol and 4-methyl pyrazole (4-MP). This study was conducted on 48 Sprague-Dawley rats, divided into 6 groups, with 8 rats in each group (one negative control group [C1], two positive control groups [C2, C3] and three test groups [1, 2 and 3]). C2, C3 and all test groups were exposed to nitrous oxide by inhalation, then, C3 group was given methanol (3 g/kg orally). The three test groups 1, 2 and 3 were given ethanol (0.5 g/kg orally), 4-MP (15 mg/kg intraperitoneally) and ranitidine (30 mg/kg intraperitoneally), respectively, 4 hours after giving methanol. Rats were sacrificed and heparinized, cardiac blood samples were collected for blood pH and bicarbonate. Non-heparinized blood samples were collected for formate levels by high performance liquid chromatography. Eye balls were enucleated for histological examination of the retina. Ranitidine corrected metabolic acidosis (p = .025), decreased formate levels (p = .014) and improved the histological findings in the retina induced by acute methanol toxicity.

Hemoglobin variants in southern China: results obtained during the measurement of glycated hemoglobin in a large population

2021 ◽  
Vol 59 (1) ◽  
pp. 227-232
Author(s):  
Anping Xu ◽  
Weidong Chen ◽  
Weijie Xie ◽  
Yajun Wang ◽  
Ling Ji
Keyword(s):  
High Performance ◽  
Southern China ◽  
Hematological Parameters ◽  
Large Population ◽  
Hypochromic Anemia ◽  
Molecular Characteristics ◽  
Inherited Disorders ◽  
Hematological Analysis ◽  
Hemoglobin Variants ◽  
Hb Variant

AbstractObjectivesHemoglobin (Hb) variant is one of the most common monogenic inherited disorders. We aimed to explore the prevalence and hematological and molecular characteristics of Hb variants in southern China.MethodsWe collected blood samples from all patients with suspected variants found during HbA1c measurement via a cation-exchange high-performance liquid chromatography system (Bio-Rad Variant II Turbo 2.0) or a capillary electrophoresis method (Sebia Capillarys). Hematological analysis, Sanger sequencing, and gap-PCR were performed for these samples.ResultsAmong the 311,024 patients tested, we found 1,074 Hb variant carriers, including 823 identified using Capillarys and 251 using Variant II Turbo 2.0, with a total carrier rate of 0.35%. We discovered 117 types of Hb variants (52 HBB, 47 HBA, and 18 HBD mutations) containing 18 new mutations. The most common variant found was Hb E, followed by Hb New York, Hb J-Bangkok, Hb Q-Thailand, Hb G-Coushatta, Hb G-Honolulu, Hb G-Taipei, and Hb Broomhill. Most heterozygotes for the Hb variant exhibited normal hematological parameters. However, most patients with compound heterozygotes for the Hb variant and thalassemia showed varied degrees of microcytic hypochromic anemia.ConclusionsThe prevalence of hemoglobin variants remains high and exhibits genetic diversity and widespread distribution in the population of southern China.

Current Developments in Diagnostic Assays for Laboratory Confirmation and Investigation of Botulism

2021 ◽  
Author(s):  
Dominick A. Centurioni ◽  
Christina T. Egan ◽  
Michael J. Perry
Keyword(s):  
Gold Standard ◽  
Botulinum Neurotoxin ◽  
Mouse Bioassay ◽  
Environmental Matrices ◽  
Animal Testing ◽  
Gold Standard Method ◽  
Diagnostic Assays ◽  
Technical Performance ◽  
Laboratory Confirmation ◽  
Testing Algorithms

Detection of botulinum neurotoxin or isolation of the toxin producing organism is required for the laboratory confirmation of botulism in clinical specimens. In an effort to reduce animal testing required by the gold standard method of botulinum neurotoxin detection, the mouse bioassay, many technologies have been developed to detect and characterize the causative agent of botulism. Recent advancements in these technologies have led to improvements in technical performance of diagnostic assays; however, many emerging assays have not been validated for the detection of all serotypes in complex clinical and environmental matrices. Improvements to culture protocols, endopeptidase-based assays, and a variety of immunological and molecular methods have provided laboratories with a variety of testing options to evaluate and incorporate into their testing algorithms. While significant advances have been made to improve these assays, additional work is necessary to evaluate these methods in various clinical matrices and to establish standardized criteria for data analysis and interpretation.

scholarly journals Rapid Diagnosis of Malaria by Antigen Detection

2009 ◽  
Vol 3 (1) ◽  
pp. 14-16
Author(s):  
Mesbah Uddin Ahmed ◽  
Md Akram Hossain ◽  
AKM Shamsuzzaman ◽  
Md Murshed Alam ◽  
Abdul Hossain Khan ◽  
...  
Keyword(s):  
Thin Films ◽  
Sensitivity And Specificity ◽  
Standard Method ◽  
Gold Standard ◽  
Rapid Diagnosis ◽  
Healthy Controls ◽  
Immunochromatographic Test ◽  
Gold Standard Method ◽  
Malaria Antigen ◽  
Age And Sex

The study was conducted to evaluate the sensitivity and specificity of Immunochromatographic test (ICT) for antigen, using microscopy as the "gold standard" method for diagnosis of malaria. A total of 98 clinically suspected malaria patients and another 30 age and sex-matched healthy controls were included in this study. Thick and thin films were also prepared and examined under microscope as well as Immunochromatographic test (ICT) was performed for malaria antigen. Sensitivity and specificity of ICT for antigen were 93.22% and 94.87% respectively. Keywords: Detection of malaria antigen, Immunochromatographic test   doi: 10.3329/bjmm.v3i1.2965 Bangladesh J Med Microbiol 2009; 03 (01): 14-16

scholarly journals Use of Circulating Tumour DNA (ctDNA) for Measurement of Therapy Predictive Biomarkers in Patients with Cancer

2022 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Michael J. Duffy ◽  
John Crown
Keyword(s):  
Gold Standard ◽  
Kinase Inhibitors ◽  
Predictive Biomarkers ◽  
Lower Sensitivity ◽  
Cancer Therapies ◽  
Gold Standard Method ◽  
Biomarker Analysis ◽  
Egfr Tyrosine Kinase Inhibitors ◽  
Biomarker Testing ◽  
Circulating Tumour Dna

Biomarkers that predict likely response or resistance to specific therapies are critical in personalising treatment for cancer patients. Such biomarkers are now available for an increasing number of anti-cancer therapies, especially targeted therapy and immunotherapy. The gold-standard method for determining predictive biomarkers requires tumour tissue. Obtaining tissue, however, is not always possible and even if possible, the amount or quality of tissue obtained may be inadequate for biomarker analysis. Tumour DNA, however, can be released into the bloodstream, giving rise to what is referred to as circulating tumour DNA (ctDNA). In contrast to tissue, blood can be obtained from effectively all patients in a minimally invasive and safe manner. Other advantages of blood over tissue for biomarker testing include a shorter turn-around time and an ability to perform serial measurements. Furthermore, blood should provide a more complete profile of mutations present in heterogeneous tumours than a single-needle tissue biopsy. A limitation of blood vis-à-vis tissue, however, is lower sensitivity and, thus, the possibility of missing an actionable mutation. Despite this limitation, blood-based predictive biomarkers, such as mutant EGFR for predicting response to EGFR tyrosine kinase inhibitors in advanced non-small-cell lung cancer and mutant PIK3CA for predicting response to alpelisib in combination with fulvestrant in advanced breast cancer, may be used when tissue is unavailable. Although tissue remains the gold standard for detecting predictive biomarkers, it is likely that several further blood-based assays will soon be validated and used when tissue is unavailable or unsuitable for analysis.

scholarly journals Evaluation of distilled water as buffered water replacement during 3% Giemsa’s solution preparation in Malaria diagnosis

2019 ◽  
Vol 10 (SPL1) ◽  
Author(s):  
Lai Yan Xia ◽  
Hamidah Abu Bakar
Keyword(s):  
Standard Method ◽  
Gold Standard ◽  
Malaria Diagnosis ◽  
Cost Effective ◽  
Peripheral Blood Smear ◽  
Blood Film ◽  
Distilled Water ◽  
Malaria Parasites ◽  
Gold Standard Method ◽  
Modified Method

Malaria is a life-threatening disease which has claimed many lives. Giemsa's stain is the gold standard method in malaria diagnosis. Generally, Giemsa's stain is diluted with buffered water. However, sometimes, it produces poor staining of the blood smears, in which can create a major challenge in detecting and identifying positive malaria parasites in a peripheral blood smear. This can lead to misdiagnosis and mistreatment to a patient. The present study examined the effect of replacing the buffered water to distilled water during the preparation of 3% Giemsa's solution. Blood specimens were collected from selected positive (n=80) and negative (n=300) malaria cases in EDTA tube. The modified method employed distilled water and different concentrations of buffered water for diluting Giemsa’s solution stock. The microscopy observation was performed on each set of blood film stained by both modified and standard Giemsa staining methods by two WHO’s qualified technicians. All Giemsa solutions with different diluents were comparable in detecting malaria parasites in the blood films. There was no difference between distilled water and different concentrations of buffered water. Furthermore, distilled water produced homogeneous staining and clearer background of the blood films, which enables different species of malaria to be identified. The present study demonstrates that the modified staining using distilled water in malaria parasites identification is comparable to the gold standard method. In addition, the modified method is rapid, easily available, cost-effective, and reliable.

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