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https://www.readbyqxmd.com/read/28822224/is-it-necessary-for-all-samples-to-quantify-25ohd2-and-25ohd3-using-lc-ms-ms-in-clinical-practice
#1
Songlin Yu, Ruiping Zhang, Weiyan Zhou, Xinqi Cheng, Qian Cheng, Liangyu Xia, Shaowei Xie, Yicong Yin, Dandan Sun, Wei Su, Ling Qiu
BACKGROUND: The demand for vitamin D testing is increasing in China. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) immunoassay is specific and accurate but requires expensive equipment, experienced operators, and complicated pretreatment of serum. Automated immunoassays are simple and convenient but only determine total 25-hydroxyvitamin D (25OHD). The objective of this study was to quantify 25OHD2 and 25OHD3 in patients to assist clinical physicians and laboratory directors in choosing the most appropriate method to determine 25OHD...
August 19, 2017: Clinical Chemistry and Laboratory Medicine: CCLM
https://www.readbyqxmd.com/read/28822164/-analysis-on-microdialysis-probe-recovery-of-baicalin-in-vitro-and-in-vivo-based-on-lc-ms-ms
#2
Teng-Fei Chen, Jian-Xun Liu, Ying Zhang, Li Lin, Wen-Ting Song, Ming-Jiang Yao
To further study the brain behavior and the pharmacokinetics of baicalin in intercellular fluid of brain, and study the recovery rate and stability of brain and blood microdialysis probe of baicalin in vitro and in vivo. The concentration of baicalin in brain and blood microdialysates was determined by LC-MS/MS and the probe recovery for baicalin was calculated. The effects of different flow rates (0.50, 1.0, 1.5, 2.0,3.0 μL•min⁻¹) on recovery in vitro were determined by incremental method and decrement method...
June 2017: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28822128/quantification-of-photorespiratory-intermediates-by-mass-spectrometry-based-approaches
#3
Stéphanie Arrivault, Toshihiro Obata
Photorespiration is an essential metabolic process in plants occurring via the oxygenase reaction of RuBisCO. In order to understand this process, it is essential to determine the amounts of intermediates involved. For this purpose we combined mass spectrometry-based approaches and the use of authentic standards for the quantification of photorespiratory intermediates. Here we describe protocols for the extraction and quantification of 2-phosphoglycolate (2PG) by LC-MS/MS and serine, glycine, glycolate, hydroxypyruvate, glyoxylate, and glycerate by GC-MS...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28822126/dimethyl-labeling-based-quantification-of-the-lysine-acetylome-and-proteome-of-plants
#4
Ines Lassowskat, Markus Hartl, Fabian Hosp, Paul J Boersema, Matthias Mann, Iris Finkemeier
Photorespiratory enzymes in different cellular compartments have been reported to be posttranslational modified by phosphorylation, disulfide formation, S-nitrosylation, glutathionylation, and lysine acetylation. However, not much is known yet about the function of these modifications to regulate the activities, localizations, or interactions of the proteins in this metabolic pathway. Hence, it will be of great importance to study these modifications and their temporal and conditional occurrence in more detail...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28821789/isolation-characterization-and-toxicological-potential-of-alternaria-mycotoxins-tea-aoh-and-ame-in-different-alternaria-species-from-various-regions-of-india
#5
Mukesh Meena, Prashant Swapnil, R S Upadhyay
Alternaria species produce various sorts of toxic metabolites during their active growth and causes severe diseases in many plants by limiting their productivity. These toxic metabolites incorporate various mycotoxins comprising of dibenzo-α-pyrone and some tetramic acid derivatives. In this study, we have screened out total 48 isolates of Alternaria from different plants belonging to different locations in India, on the basis of their pathogenic nature. Pathogenicity testing of these 48 strains on susceptible tomato variety (CO-3) showed 27...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28821766/protein-composition-analysis-of-polyhedra-matrix-of-bombyx-mori-nucleopolyhedrovirus-bmnpv-showed-powerful-capacity-of-polyhedra-to-encapsulate-foreign-proteins
#6
Zhong-Jian Guo, Meng-Han Yu, Xian-Yun Dong, Wei-Li Wang, Ting Tian, Xian-Yin Yu, Xu-Dong Tang
Polyhedra can encapsulate other proteins and have potential applications as protein stabilizers. The extremely stable polyhedra matrix may provide a platform for future engineered micro-crystal devices. However, the protein composition of the polyhedra matrix remains largely unknown. In this study, the occlusion-derived virus (ODV)-removed BmNPV polyhedra matrix fraction was subjected to SDS-PAGE and then an LC-ESI-MS/MS analysis using a Thermo Scientific Q Exactive mass spectrometer. In total, 28 host and 91 viral proteins were identified...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28821731/stability-in-metabolic-phenotypes-and-inferred-metagenome-profiles-before-the-onset-of-colitis-induced-inflammation
#7
M Glymenaki, A Barnes, S O' Hagan, G Warhurst, A J McBain, I D Wilson, D B Kell, K J Else, S M Cruickshank
Inflammatory bowel disease (IBD) is associated with altered microbiota composition and metabolism, but it is unclear whether these changes precede inflammation or are the result of it since current studies have mainly focused on changes after the onset of disease. We previously showed differences in mucus gut microbiota composition preceded colitis-induced inflammation and stool microbial differences only became apparent at colitis onset. In the present study, we aimed to investigate whether microbial dysbiosis was associated with differences in both predicted microbial gene content and endogenous metabolite profiles...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28821484/measurement-and-mathematical-characterization-of-cell-level-pharmacokinetics-of-antibody-drug-conjugates-a-case-study-with-trastuzumab-vc-mmae
#8
Aman P Singh, Dhaval K Shah
The main objective of this work was to understand and mathematically characterize the cellular disposition of a tool ADC, trastuzumab-vc-MMAE (T-vc-MMAE). Towards this goal, three different analytical methods were developed to measure the concentrations of different ADC related analytes in the media and cell lysate. An LC-MS/MS method was developed to quantify unconjugated drug (i.e. MMAE) concentrations, a forced deconjugation method was developed to quantify total drug concentrations, and an ELISA method was developed to quantify total antibody (i...
August 18, 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/28821077/building-a-fructan-lc-ms-2-library-and-its-application-to-reveal-the-fine-structure-of-cereal-grain-fructans
#9
Joran Verspreet, Anders Holmgaard Hansen, Scott J Harrison, Rudy Vergauwen, Wim Van den Ende, Christophe M Courtin
A liquid chromatography-mass spectrometry (LC-MS) library is presented containing the relative retention times of 28 fructan oligomers and MS(2) spectra of 18 of them. It includes the main representatives of all fructan classes occurring in nature and with a degree of polymerization between three and five. This library enables a rapid and unambiguous detection of these 18 fructan structures in any type of sample without the need for fructan purification or the synthesis of fructan standards. Its wide applicability is demonstrated by the analysis of fructans in a set of cereal flour samples...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821000/simultaneous-liquid-chromatography-tandem-mass-spectrometry-analysis-of-brominated-flame-retardants-tetrabromobisphenol-a-and-hexabromocyclododecane-diastereoisomers-in-french-breast-milk
#10
Chanthadary Inthavong, Frédéric Hommet, François Bordet, Virginie Rigourd, Thierry Guérin, Sylviane Dragacci
TBBPA and HBCDs are the two classes of flame retardants that are still allowed for use by the European Commission. In May 2013, HBCDs were listed as Persistent Organic Pollutants under the Stockholm Convention, and they were banned with an exemption on EPS/XPS for cavity wall insulation. This study describes the development and optimisation of a rapid LC-ESI-MS/MS method using isotopic dilution quantification including a simplified extraction step using a mixture of solvents and sulphuric acid hydrolysis followed by the one-shot analysis of TBBPA and each of the α-, β- and γ-HBCD diastereoisomers...
August 8, 2017: Chemosphere
https://www.readbyqxmd.com/read/28820983/a-sensitive-method-for-the-separation-and-quantification-of-low-level-adenine-nucleotides-using-porous-graphitic-carbon-based-liquid-chromatography-and-tandem-mass-spectrometry
#11
Sonia Bustamante, Robert B Gilchrist, Dulama Richani
A liquid chromatography coupled to heated electrospray ionization/tandem mass spectrometry (LC-HESI-MS/MS) method was developed for the simultaneous quantitative analysis of low nanomolar level adenine nucleotides AMP, ADP, ATP, cyclic AMP (cAMP), and the nucleoside adenosine. For analyte retention and separation, reverse phase chromatography using porous graphitic carbon (PGC) was employed as it provided full resolution. The erratic chromatographic behaviour characteristic of PGC, including deterioration of analyte resolution and increased peak tailing (leading to decreased sensitivity), was mitigated by incorporating acidic equilibration within runs using a quaternary gradient...
July 29, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28820982/direct-analysis-no-sample-preparation-of-bioavailable-cortisol-in-human-plasma-by-weak-affinity-chromatography-wac
#12
Sten Ohlson, Jagjit Kaur, Manfred Raida, Ulf Niss, Tim Bengala, Chester Lee Drum, Bernhard Boehm, Anthony R Torres
Pre-analytical treatment of blood plasma is a time consuming and often rate limiting step in the workflow of LC/MS analysis. We present in this pilot study a new approach for quantitative LC/MS based on weak affinity chromatography (WAC) of crude plasma. The steroid hormone cortisol was selected as a clinically relevant biomarker, as it currently requires extensive pre-analytical preparation. A WAC unit with saturating, immobilized albumin as a prototypic weak binder was used in combination with an ion-funnel MS/MS detector to perform zonal affinity chromatography of cortisol directly from a plasma sample, followed by quantitative multiple reaction monitoring (MRM)...
July 21, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28820481/studies-on-the-presence-of-mycotoxins-in-biological-samples-an-overview
#13
REVIEW
Laura Escrivá, Guillermina Font, Lara Manyes, Houda Berrada
Mycotoxins are fungal secondary metabolites with bioaccumulation levels leading to their carry-over into animal fluids, organs, and tissues. As a consequence, mycotoxin determination in biological samples from humans and animals has been reported worldwide. Since most mycotoxins show toxic effects at low concentrations and considering the extremely low levels present in biological samples, the application of reliable detection methods is required. This review summarizes the information regarding the studies involving mycotoxin determination in biological samples over the last 10 years...
August 18, 2017: Toxins
https://www.readbyqxmd.com/read/28820460/determination-of-sphingosine-1-phosphate-in-human-plasma-using-liquid-chromatography-coupled-with-q-tof-mass-spectrometry
#14
Emmanuel Eroume-A Egom, Ross Fitzgerald, Rebecca Canning, Rebabonye B Pharithi, Colin Murphy, Vincent Maher
Evidence suggests that high-density lipoprotein (HDL) components distinct from cholesterol, such as sphingosine-1-phosphate (S1P), may account for the anti-atherothrombotic effects attributed to this lipoprotein. The current method for the determination of plasma levels of S1P as well as levels associated with HDL particles is still cumbersome an assay method to be worldwide practical. Recently, a simplified protocol based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the sensitive and specific quantification of plasma levels of S1P with good accuracy has been reported...
August 18, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28820206/a-cross-platform-metabolomics-workflow-for-volume-restricted-tissue-samples-application-to-an-animal-model-for-polycystic-kidney-disease
#15
E Sánchez-López, H Happé, E Steenvoorden, A L Crego, M L Marina, D J M Peters, O A Mayboroda
Metabolic profiling provides an unbiased view of the physiological status of an organism as a "function" of the metabolic composition of a measured sample. Here, we propose a simple LC-MS based workflow for metabolic profiling of volume-restricted samples, namely individual 20 μm-thick histological sections of a mouse kidney. The main idea of this workflow is to re-use the material after an RPLC-MS run, namely using the volume remaining in the vial after injection, and then introducing a phase changing step to enable HILIC-MS analysis...
August 18, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28819550/effects-of-storage-temperature-on-airway-exosome-integrity-for-diagnostic-and-functional-analyses
#16
Rosario Maroto, Yingxin Zhao, Mohammad Jamaluddin, Vsevolod L Popov, Hongwang Wang, Madumali Kalubowilage, Yueqing Zhang, Jonathan Luisi, Hong Sun, Christopher T Culbertson, Stefan H Bossmann, Massoud Motamedi, Allan R Brasier
Background: Extracellular vesicles contain biological molecules specified by cell-type of origin and modified by microenvironmental changes. To conduct reproducible studies on exosome content and function, storage conditions need to have minimal impact on airway exosome integrity. Aim: We compared surface properties and protein content of airway exosomes that had been freshly isolated vs. those that had been treated with cold storage or freezing. Methods: Mouse bronchoalveolar lavage fluid (BALF) exosomes purified by differential ultracentrifugation were analysed immediately or stored at +4°C or -80°C...
2017: Journal of Extracellular Vesicles
https://www.readbyqxmd.com/read/28819353/a-metabolomics-guided-exploration-of-marine-natural-product-chemical-space
#17
Dimitrios J Floros, Paul R Jensen, Pieter C Dorrestein, Nobuhiro Koyama
INTRODUCTION: Natural products from culture collections have enormous impact in advancing discovery programs for metabolites of biotechnological importance. These discovery efforts rely on the metabolomic characterization of strain collections. OBJECTIVE: Many emerging approaches compare metabolomic profiles of such collections, but few enable the analysis and prioritization of thousands of samples from diverse organisms while delivering chemistry specific read outs...
September 2016: Metabolomics: Official Journal of the Metabolomic Society
https://www.readbyqxmd.com/read/28819266/amalaki-rasayana-a-traditional-indian-drug-enhances-cardiac-mitochondrial-and-contractile-functions-and-improves-cardiac-function-in-rats-with-hypertrophy
#18
Vikas Kumar, Kumar A Aneesh, K Kshemada, Kumar G S Ajith, Raj S S Binil, Neha Deora, G Sanjay, A Jaleel, T S Muraleedharan, E M Anandan, R S Mony, M S Valiathan, Kumar T R Santhosh, C C Kartha
We evaluated the cardioprotective effect of Amalaki Rasayana (AR), a rejuvenating Ayurvedic drug prepared from Phyllanthus emblica fruits in the reversal of remodeling changes in pressure overload left ventricular cardiac hypertrophy (LVH) and age-associated cardiac dysfunction in male Wistar rats. Six groups (aging groups) of 3 months old animals were given either AR or ghee and honey (GH) orally; seventh group was untreated. Ascending aorta was constricted using titanium clips in 3 months old rats (N = 24; AC groups) and after 6 months, AR or GH was given for further 12 months to two groups; one group was untreated...
August 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28819071/genetic-and-non-genetic-factors-associated-with-protein-abundance-of-flavin-containing-monooxygenase-3-in-human-liver
#19
Meijuan Xu, Deepak Kumar Bhatt, Catherine K Yeung, Katrina G Claw, Amarjit S Chaudhry, Andrea Gaedigk, Robin E Pearce, Ulrich Broeckel, Roger Gaedigk, Debbie Nickerson, Erin Schuetz, Allan E Rettie, Steven Leeder, Kenneth E Thummel, Bhagwat Prasad
Hepatic flavin-containing monooxygenase 3 (FMO3) metabolizes a broad array of nucleophilic heteroatom (e.g., N or S)-containing xenobiotics (e.g., amphetamine, sulindac, benzydamine, ranitidine, tamoxifen, nicotine, and ethioniamide), as well as endogenous compounds (e.g., catecholamine and trimethylamine). To predict the effect of genetic and non-genetic factors on the hepatic metabolism of FMO3 substrates, we quantified FMO3 protein abundance in human liver microsomes (HLM; n=445) by LC-MS/MS proteomics. Genotyping/gene-resequencing, mRNA expression, and functional activity (with benzydamine as a probe substrate) of FMO3 were also performed...
August 17, 2017: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/28818804/an-on-spot-internal-standard-addition-approach-for-accurately-determining-colistin-a-and-colistin-b-in-dried-blood-spots-using-ultra-high-performance-liquid-chromatography-tandem-mass-spectrometry
#20
I-Lin Tsai, Ching-Hua Kuo, Hsin-Yun Sun, Yu-Chung Chuang, Divyabharathi Chepyala, Shu-Wen Lin, Yun-Jung Tsai
Outbreaks of multidrug-resistant Gram-negative bacterial infections have been reported worldwide. Colistin, an antibiotic with known nephrotoxicity and neurotoxicity, is now being used to treat multidrug-resistant Gram-negative strains. In this study, we applied an on-spot internal standard addition approach coupled with an ultra high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify colistin A and B from dried blood spots (DBSs). Only 15μL of whole blood was required for each sample...
August 3, 2017: Journal of Pharmaceutical and Biomedical Analysis
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