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https://www.readbyqxmd.com/read/28820982/direct-analysis-no-sample-preparation-of-bioavailable-cortisol-in-human-plasma-by-weak-affinity-chromatography-wac
#1
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/28815991/functional-response-and-multiple-predator-effects-of-two-generalist-predators-preying-on-tuta-absoluta-eggs
#2
Georgios Michaelides, Spyros Sfenthourakis, Maria Pitsillou, Nicos Seraphides
BACKROUND: Interactions among invertebrate predators could affect a pest suppression. The hemipteran species Macrolophus pygmaeus (Rambur) and Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) are natural enemies of several pests in agroecosystems and coexist in tomato crops in Mediterranean countries. By using the multiplicative risk model (MRM) and the substitutive model, the multiple predator effects (MPEs) on prey suppression was calculated when two individuals of the predators foraged at the same densities of the South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), eggs...
August 16, 2017: Pest Management Science
https://www.readbyqxmd.com/read/28814639/deposition-and-hydrolysis-of-serine-dipeptide-lipids-of-bacteroidetes-bacteria-in-human-arteries-relationship-to-atherosclerosis
#3
Reza Nemati, Christopher Dietz, Emily J Anstadt, Jorge Cervantes, Yaling Liu, Floyd E Dewhirst, Robert B Clark, Sydney Finegold, James J Gallagher, Michael B Smith, Xudong Yao, Frank C Nichols
Multiple reaction monitoring mass spectrometry (MRM-MS) analysis of lipid extracts from human carotid endarterectomy and carotid artery samples from young individuals consistently demonstrated the presence of bacterial serine dipeptide lipid classes including Lipid 654, an agonist for human and mouse Toll-like receptor 2, and Lipid 430, the deacylated product of Lipid 654. The relative levels of Lipid 654 and Lipid 430 were also determined in common oral and intestinal bacteria from the phylum Bacteroidetes, and human serum and brain samples from healthy adults...
August 16, 2017: Journal of Lipid Research
https://www.readbyqxmd.com/read/28808995/high-resolution-parallel-reaction-monitoring-with-electron-transfer-dissociation-for-middle-down-proteomics-an-application-to-study-the-quantitative-changes-induced-by-histone-modifying-enzyme-inhibitors-and-activators
#4
Michael J Sweredoski, Annie Moradian, Sonja Hess
With the advent of new methodologies, proteomics-based assays are increasingly used to study the efficacy of drugs on a molecular level. For these studies to be meaningful, the proteomics assays need to be sensitive, selective, accurate, and reproducible. This is often accomplished through a targeted approach, either using single or multiple reaction monitoring (SRM/MRM) or, more recently, parallel reaction monitoring (PRM). In PRM, the parallel detection of all product ions in a high-resolution mass spectrometer affords higher selectivity than SRM/MRM...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28808993/multiplexed-liquid-chromatography-multiple-reaction-monitoring-mass-spectrometry-quantification-of-cancer-signaling-proteins
#5
Yi Chen, Kate J Fisher, Mark Lloyd, Elizabeth R Wood, Domenico Coppola, Erin Siegel, David Shibata, Yian A Chen, John M Koomen
Quantitative evaluation of protein expression across multiple cancer-related signaling pathways (e.g., Wnt/β-catenin, TGF-β, receptor tyrosine kinases (RTK), MAP kinases, NF-κB, and apoptosis) in tumor tissues may enable the development of a molecular profile for each individual tumor that can aid in the selection of appropriate targeted cancer therapies. Here, we describe the development of a broadly applicable protocol to develop and implement quantitative mass spectrometry assays using cell line models and frozen tissue specimens from colon cancer patients...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28805683/analysis-and-comparison-of-the-antioxidant-component-of-portulaca-oleracea-leaves-obtained-by-different-solid-liquid-extraction-techniques
#6
Monica Gallo, Esterina Conte, Daniele Naviglio
Portulaca oleracea is a wild plant pest of orchards and gardens, but is also an edible vegetable rich in beneficial nutrients. It possesses many antioxidant properties due to the high content of vitamins, minerals, omega-3 essential fatty acids and other healthful compounds; therefore, the intake of purslane and/or its bioactive compounds could help to improve the health and function of the whole human organism. Accordingly, in this work it was analyzed and compared to the extractive capacity of the antioxidant component of purslane leaves obtained by solid-liquid extraction techniques such as: hot-maceration, maceration with ultrasound, rapid solid-liquid dynamic extraction using the Naviglio extractor, and a combination of two techniques (mix extraction)...
August 12, 2017: Antioxidants (Basel, Switzerland)
https://www.readbyqxmd.com/read/28802242/an-lc-ms-ms-method-for-simultaneous-determination-of-nine-steroidal-saponins-from-paris-polyphylla-var-in-rat-plasma-and-its-application-to-pharmacokinetic-study
#7
Guangyi Yang, Wei Lu, Meng Pan, Chenning Zhang, Yuan Zhou, Pei Hu, Ming Hu, Gao Song
Paris polyphylla var is an herbal plant herb widely used in Traditional Chinese Medicine. The purpose of this study is to develop an Ultra Performance Liquid Chromatography-tandem mass spectrometer (UPLC-MS) method to quantify the major components (i.e., nine saponins) from P. polyphylla in plasma samples. A UItra BiPh column (100×2.1mm, 5μm) was used with acetonitrile/0.1% formic acid in water as mobile phases. The analytes were quantified using a Waters XEVO TQ mass spectrometer via multiple reaction monitoring (MRM) with positive scan mode...
August 1, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28802217/comparatively-evaluating-the-pharmacokinetic-of-fifteen-constituents-in-normal-and-blood-deficiency-rats-after-oral-administration-of-xin-sheng-hua-granule-by-uplc-ms-ms
#8
Han-Qing Pang, Yu-Ping Tang, Yu-Jie Cao, Ya-Jie Tan, Yi Jin, Xu-Qin Shi, Sheng-Liang Huang, Da-Zheng Sun, Jin Sun, Zhi-Shu Tang, Jin-Ao Duan
Xin-Sheng-Hua Granule (XSHG), a famous traditional Chinese medicine prescription, are clinically applied for the treatment of postpartum disease through nourishing blood and promoting blood circulation. In this investigation, a multi-constituents (trigonelline, stachydrine hydrochloride, hydroxysafflor yellow A, chlorogenic acid, amygdalin, leonurine, liquiritin, ferulic acid, senkyunolide I, senkyunolide H, glycyrrhizic acid, senkyunolide A, ligustilide, butylidenephthalide and glycyrrhetinic acid) pharmacokinetic study of XSHG was conducted for the first time...
July 30, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28801836/optimization-of-sample-preparation-and-instrumental-parameters-for-the-rapid-analysis-of-drugs-of-abuse-in-hair-samples-by-maldi-ms-ms-imaging
#9
Bryn Flinders, Emma Beasley, Ricky M Verlaan, Eva Cuypers, Simona Francese, Tom Bassindale, Malcolm R Clench, Ron M A Heeren
Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) has been employed to rapidly screen longitudinally sectioned drug user hair samples for cocaine and its metabolites using continuous raster imaging. Optimization of the spatial resolution and raster speed were performed on intact cocaine contaminated hair samples. The optimized settings (100 × 150 μm at 0.24 mm/s) were subsequently used to examine longitudinally sectioned drug user hair samples. The MALDI-MS/MS images showed the distribution of the most abundant cocaine product ion at m/z 182...
August 11, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28801822/simultaneous-quantification-of-free-cholesterol-cholesteryl-esters-and-triglycerides-without-ester-hydrolysis-by-uhplc-separation-and-in-source-collision-induced-dissociation-coupled-ms-ms
#10
Michael S Gardner, Lisa G McWilliams, Jeffrey I Jones, Zsuzsanna Kuklenyik, James L Pirkle, John R Barr
We demonstrate the application of in-source nitrogen collision-induced dissociation (CID) that eliminates the need for ester hydrolysis before simultaneous analysis of esterified cholesterol (EC) and triglycerides (TG) along with free cholesterol (FC) from human serum, using normal phase liquid chromatography (LC) coupled to atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). The analysis requires only 50 μL of 1:100 dilute serum with a high-throughput, precipitation/evaporation/extraction protocol in one pot...
August 11, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28783006/development-of-a-confirmatory-method-for-detecting-recombinant-bovine-somatotropin-in-plasma-by-immunomagnetic-precipitation-followed-by-ultra-high-performance-liquid-chromatography-coupled-to-tandem-mass-spectrometry
#11
Christelle Robert, Anne-Catherine Huet, Célia Suárez-Pantaleón, Amaury Brasseur, Philippe Delahaut, Nathalie Gillard
Recombinant bovine somatotropin (rbST), a synthetic growth hormone, is used to stimulate growth and enhance milk production in dairy cows. Both its use and the sale of dairy products from treated animals are prohibited in the European Union, Japan, Australia, New Zealand, and Canada, but authorised in several countries (e.g. the USA, Brazil). Screening methods involve detecting anti-rbST antibodies (biomarkers) in treated cows. Confirmatory methods are required to prove rbST abuse. The major challenges in determining rbST are its potentially low levels, its high similarity to native bST, and matrix interferences...
August 7, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28766761/a-comparison-of-esi-apci-and-appi-ionization-for-the-lc-ms-ms-analysis-of-bisphenols-application-to-bisphenols-in-thermal-paper-receipts-and-u-s-currency-notes
#12
Henry J Eichman, Bryan J Eck, Anthony F Lagalante
RATIONALE: Human health concerns have arisen for common bisphenols (BPA and BPS) as well as new structural analogs. While native sulfone bisphenols and sulfone derivatized bisphenols are amenable to ESI, alternative ionization methods such as APCI and APPI were investigated to analyze non-derivatized, non-sulfone containing bisphenols. METHODS: Ionization of bisphenols using negative ion APPI was compared to negative ion ESI and negative ion APCI for their relative abilities to produce [M-H](-) precursor ions for subsequent collision activated dissociation (CAD) in a triple quadrupole mass analyzer...
August 2, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28764013/stable-isotope-labeling-solid-phase-extraction-mass-spectrometry-analysis-for-profiling-of-thiols-and-aldehydes-in-beer
#13
Shu-Jian Zheng, Ya-Lan Wang, Ping Liu, Zheng Zhang, Lei Yu, Bi-Feng Yuan, Yu-Qi Feng
In this study, we developed a strategy for profiling of thiols and aldehydes in beer samples by stable isotope labeling-solid phase extraction-liquid chromatography-double precursor ion scan/double neutral loss scan-mass spectrometry analysis (SIL-SPE-LC-DPIS/DNLS-MS). A pair of isotope reagents (ω-bromoacetonylquinolinium bromide, BQB; ω-bromoacetonylquinolinium-d7 bromide, BQB-d7) were used to label thiols; while for the aldehydes, a pair of isotope reagents (4-(2-(trimethylammonio) ethoxy) benzenaminium halide, 4-APC; 4-(2-(trimethylammonio) ethoxy) benzenaminium halide-d4, 4-APC-d4) were used...
December 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28763758/simultaneous-determination-of-three-di-caffeoylquinic-acids-by-uhplc-ms-ms-in-rat-plasma-and-its-application-to-a-comparative-pharmacokinetic-study-in-normal-and-acute-lung-injury-rat
#14
Yanjuan Wang, Yanmin Wang, Xiao Wu, Zhili Xiong, Wei Xiao, Chao Ma
Acute lung injury (ALI) is a severe inflammatory disease with high mortality rates. Di-caffeoylquinic acids (DCQAs), the bioactive components of reduning injection (RDN), may play important roles in the protective effect on acute lung injury (ALI). A selective and rapid ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed and validated for the simultaneous determination of 3,4-, 3,5- and 4,5-DCQA in rat plasma. The DCQAs were extracted by liquid-liquid extraction with ethyl acetate-isopropyl alcohol (7:3, v/v)...
July 25, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28762319/quantification-of-sulfotransferase-1a-isoforms-in-human-tissue-fractions-and-cell-lines-by-multiple-reaction-monitoring-mass-spectrometry
#15
Sho Yoshitake, Melissa McKay-Daily, Masaki Tanaka, Zeqi Huang
BACKGROUND: Within the sulfotransferase (SULT) superfamily of metabolic enzymes, the SULT1A family of cytosolic sulfotransferases is of particular interest, due to its ability to catalyze the sulfation of phenolic substrates. In humans, there are three distinct SULT1A enzymes: SULT1A1, SULT1A2, and SULT1A3/4. OBJECTIVE: To detect and quantify these enzymes in S9 fractions and cell lines using targeted mass spectrometry-based proteomics. METHOD: Samples were tryptically digested, and signature peptides were quantified using liquid chromatography-multiple reaction monitoring mass spectrometry (LC-MRM/MS)...
July 31, 2017: Drug Metabolism Letters
https://www.readbyqxmd.com/read/28761571/extending-inferential-group-analysis-in-type-2-diabetic-patients-with-multivariate-glm-implemented-in-spm8
#16
Fábio S Ferreira, João M S Pereira, João V Duarte, Miguel Castelo-Branco
BACKGROUND: Although voxel based morphometry studies are still the standard for analyzing brain structure, their dependence on massive univariate inferential methods is a limiting factor. A better understanding of brain pathologies can be achieved by applying inferential multivariate methods, which allow the study of multiple dependent variables, e.g. different imaging modalities of the same subject. OBJECTIVE: Given the widespread use of SPM software in the brain imaging community, the main aim of this work is the implementation of massive multivariate inferential analysis as a toolbox in this software package...
2017: Open Neuroimaging Journal
https://www.readbyqxmd.com/read/28757464/an-online-2d-reversed-phase-reversed-phase-chromatographic-method-for-sensitive-and-robust-plasma-protein-quantitation
#17
Vincent R Richard, Dominik Domanski, Andrew J Percy, Christoph H Borchers
Offline high-pH reversed-phase fractionation is widely used to reduce sample complexity in proteomic workflows. This is due to the semi-orthogonality and high peak resolution of the two separations. Offline 2D fractionation, however, is low throughput and requires several manual manipulations and is prone to sample losses. To address these issues, we developed an online two dimensional high-pH - low-pH reversed-phase-reversed-phase LC-MRM (2D RPRP) method whereby hundreds of peptides can be quantified in a single LC-MS/MS injection...
July 27, 2017: Journal of Proteomics
https://www.readbyqxmd.com/read/28756650/accurate-quantification-of-five-german-cockroach-gcr-allergens-in-complex-extracts-using-multiple-reaction-monitoring-mass-spectrometry-mrm-ms
#18
Samuel T Mindaye, Jelena Spiric, Natalie A David, Ronald L Rabin, Jay E Slater
BACKGROUND: German cockroach (GCr) allergen extracts are complex and heterogeneous products, and methods to better assess their potency and composition are needed for adequate studies of their safety and efficacy. OBJECTIVE AND METHODS: The objective of this study was to develop an assay based on liquid chromatography and multiple reaction monitoring mass spectrometry (LC-MRM MS) for rapid, accurate, and reproducible quantification of five allergens (Bla g 1, Bla g 2, Bla g3, Bla g 4, and Bla g 5) in crude GCr allergen extracts...
July 30, 2017: Clinical and Experimental Allergy: Journal of the British Society for Allergy and Clinical Immunology
https://www.readbyqxmd.com/read/28755445/squantification-of-free-fatty-acids-in-human-stratum-corneum-using-tandem-mass-spectrometry-and-surrogate-analyte-approach
#19
Irena Dapic, Renata Kobetic, Lidija Brkljacic, Sanja Kezic, Ivone Jakasa
The free fatty acids (FFAs) are one of the major components of the lipids in the stratum corneum (SC), the uppermost layer of the skin. Relative composition of FFAs has been proposed as a biomarker of the skin barrier status in patients with atopic dermatitis (AD). Here, we developed LC-ESI-MS/MS method for simultaneous quantification of a range of FFAs with long and very-long chain length in the SC collected by an adhesive tape (D-Squame). Method based on derivatization with 2-bromo-1-methylpyridinium iodide (BMP) and 3-carbinol-1-methylpyridinium iodide (CMP) allowed highly sensitive detection and quantification of FFAs using multiple reaction monitoring (MRM)...
July 29, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28753737/uplc-ms-ms-method-for-therapeutic-drug-monitoring-of-ten-antibiotics-used-in-intensive-care-units
#20
Nahed El-Najjar, Julian Hösl, Thomas Holzmann, Jonathan Jantsch, André Gessner
Large variation in the levels of different ß-lactams and other antibiotics used in critically ill patients has been documented. The aim of this study is to establish and validate a fast ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous analysis of ten antibiotics (Meropenem, Cefepime, Ceftazidime, Piperacillin, Benzylpenicillin, Ampicillin, Flucloxacillin, Linezolid, and Sulfamethoxazole/Trimethoprim) in human plasma according to European Medicines Agency (EMA) guidelines...
July 28, 2017: Drug Testing and Analysis
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