keyword
MENU ▼
Read by QxMD icon Read
search

LC-MSMS

keyword
https://www.readbyqxmd.com/read/29198640/serum-testosterone-levels-in-prostate-cancer-patients-undergoing-luteinizing-hormone-releasing-hormone-agonist-therapy
#1
Juan Morote, Inma Comas, Jacques Planas, Xavier Maldonado, Ana Celma, José Placer, Roser Ferrer, Joan Carles, Lucas Regis
BACKGROUND: Serum testosterone measurement is recommended to assess the efficacy of androgen deprivation therapy (ADT) and to diagnose castration resistance in patients with prostate cancer (PCa). Currently, the accepted castrate level of serum testosterone is 50 ng/dL. Liquid chromatography and tandem mass spectrometry (LC MSMS) is the appropriate method to measure testosterone, especially at low levels. However, worldwide, chemiluminescent assays (CLIAs) are used in clinical laboratories, despite their lack of accuracy and reproducibility, because they are automatable, fast, sensitive, and inexpensive...
November 30, 2017: Clinical Genitourinary Cancer
https://www.readbyqxmd.com/read/29173162/oral-fluid-vs-urine-analysis-to-monitor-synthetic-cannabinoids-and-classic-drugs-recent-exposure
#2
Marta Concheiro, Vincent Blandino, Jillian Wetzel, Jiyoung Kim, Petrit Haxhi
BACKGROUND: Urine is a common biological sample to monitor recent drug exposure, and oral fluid is an alternative matrix of increasing interest in clinical and forensic toxicology. Limited data are available about oral fluid vs. urine drug disposition, especially for synthetic cannabinoids. OBJECTIVE: To compare urine and oral fluid as biological matrices to monitor recent drug exposure among HIV-infected homeless individuals. METHODS: Seventy matched urine and oral fluid samples were collected from 13 participants...
November 21, 2017: Current Pharmaceutical Biotechnology
https://www.readbyqxmd.com/read/29058606/accuracy-of-serum-luteinizing-hormone-and-serum-testosterone-measurements-to-assess-the-efficacy-of-medical-castration-in-prostate-cancer-patients
#3
Juan Morote, Imma Comas, Roser Ferrer, Jacques Planas, Anna Celma, Lucas Regis
BACKGROUND: Luteinizing hormone-releasing hormone (LH-RH) agonists are the standard for androgen deprivation therapy (ADT) in prostate cancer (PCa) patients. Current guidelines recommend serum testosterone measurement to assess the efficacy of ADT and to define castration resistance. However, serum testosterone does not reflect the exclusive effect of castration due to its extratesticular production. The aim of this study is to analyze if serum LH reflects better than serum testosterone the activity of LH-RH agonists...
October 22, 2017: Journal of Biomedical Science
https://www.readbyqxmd.com/read/28940782/ptca-1h-pyrrole-2-3-5-tricarboxylic-acid-as-a-marker-for-oxidative-hair-treatment
#4
Silvana Petzel-Witt, Sylvia I Meier, Manfred Schubert-Zsilavecz, Stefan W Toennes
Hair analysis for the assessment of alcohol or drug abstinence became a routine procedure in forensic toxicology. Hair coloration leading to loss of incorporated xenobiotics and to false negative results turned out to be a major problem. Currently only colored extracts provide hints of manipulations but not bleaching. A liquid chromatographic-mass spectrometric (LC-MSMS) method was developed and validated to determine 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA), a major oxidation product of melanin. PTCA was determined in natural hair samples (n=21) after treatment with 3% hydrogen peroxide (H2 O2 ) for 30 or 40 min with concentrations up to 12% for 40 min...
September 20, 2017: Drug Testing and Analysis
https://www.readbyqxmd.com/read/28873407/photo-affinity-labelling-and-biochemical-analyses-identify-the-target-of-trypanocidal-simplified-natural-product-analogues
#5
Lindsay B Tulloch, Stefanie K Menzies, Andrew L Fraser, Eoin R Gould, Elizabeth F King, Marija K Zacharova, Gordon J Florence, Terry K Smith
Current drugs to treat African sleeping sickness are inadequate and new therapies are urgently required. As part of a medicinal chemistry programme based upon the simplification of acetogenin-type ether scaffolds, we previously reported the promising trypanocidal activity of compound 1, a bis-tetrahydropyran 1,4-triazole (B-THP-T) inhibitor. This study aims to identify the protein target(s) of this class of compound in Trypanosoma brucei to understand its mode of action and aid further structural optimisation...
September 2017: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/28777977/relationship-between-reactive-oxygen-species-and-water-soluble-organic-compounds-time-resolved-benzene-carboxylic-acids-measurement-in-the-coastal-area-during-the-korus-aq-campaign
#6
Min-Suk Bae, James J Schauer, Taehyoung Lee, Ju-Hee Jeong, Yoo-Keun Kim, Chul-Un Ro, Sang-Keun Song, Zang-Ho Shon
This study investigated the relationship between water-soluble organic compounds of ambient particulate matter (PM) and cellular redox activity collected from May 28 to June 20 of 2016 at the west coastal site in the Republic of Korea during the KORea-US Air Quality (KORUS-AQ) campaign. Automatic four-hour integrated samples operated at a flow rate of 92 L per minute for the analysis of organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), water-soluble ions (WSIs), and benzene carboxylic acids (BCAs) were collected on a 47 mm quartz fiber filter...
December 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28743623/novel-mannose-binding-natterin-like-protein-in-the-skin-mucus-of-atlantic-cod-gadus-morhua
#7
Binoy Rajan, Deepti M Patel, Yoichiro Kitani, Kiron Viswanath, Monica F Brinchmann
This study presents the first report of purification of natterin-like protein (Nlp) in a non-venomous fish. The peptide identities of purified cod Nlp were confirmed through LC-MSMS and matched to a cod expressed sequence tag (EST). A partial cod nlp nucleotide sequence was amplified and sequenced based on this EST. Multiple sequence alignment of cod Nlp showed considerable homology with other teleost Nlps and the presence of an N-terminal jacalin-like lectin domain coupled with a C-terminal toxin domain. nlp expression was higher in skin, head kidney, liver and spleen than in other tissues studied...
September 2017: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/28725138/comparative-assessment-of-saliva-and-plasma-for-drug-bioavailability-and-bioequivalence-studies-in-humans
#8
Nasir M Idkaidek
Aims: To study the pharmacokinetics of selected drugs in plasma and saliva matrixes in healthy human volunteers, and to suggest using non-invasive saliva sampling instead of plasma as a surrogate in bioavailability and bioequivalence (BA/BE) studies. Methods: Four different pilot BA/BE studies were done in 12-18 healthy humans. Saliva and plasma samples were collected for 3-5 half life values of metformin, tolterodine, rosuvastatin, and paracetamol after oral dosing. Saliva and plasma samples were assayed using LC-MSMS, and then pharmacokinetic parameters were calculated by non-compartmental analysis using Kinetica program...
July 2017: Saudi Pharmaceutical Journal: SPJ: the Official Publication of the Saudi Pharmaceutical Society
https://www.readbyqxmd.com/read/28694743/interferon-%C3%AE-induced-compositional-changes-in-human-bone-marrow-derived-mesenchymal-stem-stromal-cells
#9
Qingdong Guan, Peyman Ezzati, Victor Spicer, Oleg Krokhin, Donna Wall, John A Wilkins
BACKGROUND: Mesenchymal stem/stromal cells (MSC) display a range of immunoregulatory properties which can be enhanced by the exposure to cytokines such interferon γ (IFN-γ). However the compositional changes associated with the 'licensing' of these cells have not been clearly defined. The present study was undertaken to provide a detailed comparative proteomic analysis of the compositional changes that occur in human bone marrow derived MSC following 20 h treatment with IFN-γ. METHODS: 2D LC MSMS analysis of control and IFN-γ treated cells from 5 different healthy donors provided confident identification of more than 8400 proteins...
2017: Clinical Proteomics
https://www.readbyqxmd.com/read/28676664/itraq-based-quantitative-proteomic-analysis-of-the-inhibitory-effects-of-polysaccharides-from-viscum-coloratum-kom-nakai-on-hepg2-cells
#10
Yangyang Chai, Min Zhao
Viscum coloratum (Kom.) Nakai is one of active medicinal plants, and its active components, especially polysaccharides, have been shown to exhibit bioactivity. In this study, we examined the effects of three polysaccharide fractions from Viscum coloratum (Kom.) Nakai on HepG2 cell growth in a dose-dependent manner by using a CCK-8 assay kit. Flow cytometry analysis showed that VCP2 treatment delayed the cell cycle in the G1 phase and induced apoptosis in HepG2 cells, a result possibly due to the increased expression of p21(Wafl/Cip1) and Cyclin D and the decreased expression of Cyclin E and CDK4...
July 4, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28644875/estimation-of-the-optimal-dosing-regimen-of-escitalopram-in-dogs-a-dose-occupancy-study-with-11c-dasb
#11
Olivia Taylor, Nick Van Laeken, Ingeborgh Polis, Robrecht Dockx, Lise Vlerick, Andre Dobbeleir, Ingeborg Goethals, Jimmy Saunders, Nele Sadones, Chris Baeken, Filip De Vos, Kathelijne Peremans
Although the favourable characteristics of escitalopram as being the most selective serotonin reuptake inhibitor and having an increased therapeutic efficacy via binding on an additional allosteric binding site of the serotonin transporter, its dosing regimen has not yet been optimized for its use in dogs. This study aimed to estimate the optimal dosing frequency and the required dose for achieving 80% occupancy of the serotonin transporters in the basal ganglia. The dosing frequency was investigated by determining the elimination half-life after a four day oral pre-treatment period with 0...
2017: PloS One
https://www.readbyqxmd.com/read/28456451/high-sensitivity-determination-of-estrogens-in-fish-plasma-using-chemical-derivatization-upstream-uhplc-msms
#12
Ugo Bussy, Yu-Wen Chung-Davidson, Tyler J Buchinger, Ke Li, Weiming Li
This article describes the development and validation of a sensitive LC-MSMS method for determination of estrogen in fish plasma. Dansyl chloride derivatization of the phenol functional group in estrogen was used to enhance the response to atmospheric pressure ionization leading to improve the sensitivity. Individual (13)C internal standards were selected after comparison with deuterated standards. Liquid-liquid extraction (ethyl acetate or methyl tert-butyl ether) and protein precipitation (acetonitrile, methanol or acetone) were compared for the extraction and clean-up of estrogens from fish plasma...
April 27, 2017: Steroids
https://www.readbyqxmd.com/read/28438686/expression-purification-and-molecular-characterization-of-a-novel-endoglucanase-protein-from-bacillus-subtilis-sb13
#13
Xuefang Guan, Penglian Chen, Qingxian Xu, Lei Qian, Juqing Huang, Bin Lin
Bacillus subtilis strain SB13 which is isolated in our previous work was confirmed to produce endoglucanase. In this study, a novel endoglucanase gene (accession number: KX576676) was identified and cloned from SB13. Compared with other consensus sequence of reported endoglucanase genes in the GenBank database, this gene displays five differences (including T740C,A874G,A983G, T1210G and T1301C), which leading to five amino acid changes. Homology modeling has indicated that these five changes were located in the α-helix and random coil regions of the glycosyl hydrolase family 5 (GH5) domain, the random coil and β-sandwich of the type 3 carbohydrate-binding module (CBM3) domain, and the random coil domain...
June 2017: Protein Expression and Purification
https://www.readbyqxmd.com/read/28406359/enantioselective-analysis-of-chloramphenicol-residues-in-honey-samples-by-chiral-lc-ms-ms-and-results-of-a-honey-survey
#14
Gerhard G Rimkus, Dirk Hoffmann
Chloramphenicol (CAP) is a broad-spectrum antibiotic used widely in both human and veterinary medication. Since 1994, CAP has not been authorised for use in food-producing animals in the European Union due to several adverse effects. A minimum required performance level (MRPL) of 0.3 µg kg(-)(1) was established in 2003. The CAP molecule contains two asymmetric centres, thus in total four para-CAP stereoisomers exist. Only the RR-CAP enantiomer is bioactive, having significant antimicrobial activity. For the first time a chiral LC-MS/MS method is reported to identify and quantify the four CAP enantiomers at residue levels in honey samples...
June 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28372838/development-and-validation-of-a-liquid-chromatography-tandem-mass-spectrometry-method-for-the-determination-of-cannabinoids-and-phase-i-and-ii-metabolites-in-meconium
#15
Pablo Prego-Meleiro, Elena Lendoiro, Marta Concheiro, Angelines Cruz, Manuel López-Rivadulla, Ana de Castro
A liquid chromatography-tandem mass spectrometry (LC-MSMS) method was developed and fully validated for the determination of Δ(9)-tetrahydrocannabinol (THC), 11-hydroxyTHC (OHTHC), 11-nor-9-carboxyTHC (THCCOOH), 8-β-11-dihydroxyTHC (diOHTHC), cannabinol, cannabidiol, and THC and THCCOOH glucuronides in 0.25±0.02g meconium. Samples were homogenized in methanol and subjected to cation exchange solid-phase extraction. Chromatographic separation was performed on a Kinetex C18 column (50 mm×2.1mm, 2.6μm) at 35°C, with a gradient of 0...
May 12, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28365515/pharmacokinetic-properties-of-the-synthetic-cannabinoid-jwh-018-and-of-its-metabolites-in-serum-after-inhalation
#16
Stefan W Toennes, Anna Geraths, Werner Pogoda, Alexander Paulke, Cora Wunder, Eef L Theunissen, Johannes G Ramaekers
Each year, synthetic cannabinoids are occurring in high numbers in the illicit drug market, but data on their pharmacology and toxicology are scarcely available. Therefore, a pilot study was performed to assess adverse effects of JWH-018, which is one of the oldest and best known synthetic cannabinoids. Six subjects inhaled smoke from 2 and 3mg JWH-018. The drug and nine of its metabolites were analyzed in their blood samples taken during the following 12h by liquid chromatography-mass spectrometry (LC-MSMS)...
June 5, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28344167/protection-and-antibody-reactivity-following-vaccination-of-lumpfish-cyclopterus-lumpus-l-against-atypical-aeromonas-salmonicida
#17
Anita Rønneseth, Gyri T Haugland, Duncan J Colquhoun, Espen Brudal, Heidrun I Wergeland
Atypical Aeromonas salmonicida is frequently associated with disease and mortality in farmed lumpfish (Cyclopterus lumpus L). Challenge experiments using different modes of exposure identified both high and low pathogenic isolates. Intraperitoneal vaccination induced production of high levels of specific antibodies particularly in fish given multiple injections. The immune sera contained antibodies cross reactive with both high and low pathogenic isolates. SDS-PAGE and LC/MSMS analyses showed that the highly virulent isolate expressed the virulence array protein (A-layer) while the less virulent isolate did not...
May 2017: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/28259362/a-systematic-review-of-methods-for-quantifying-serum-testosterone-in-patients-with-prostate-cancer-who-underwent-castration
#18
I Comas, R Ferrer, J Planas, A Celma, L Regis, J Morote
BACKGROUND: The clinical practice guidelines recommend measuring serum testosterone in patients with prostate cancer (PC) who undergo castration. The serum testosterone concentration should be <50ng/dL, a level established by using a radioimmunoassay method. The use of chemiluminescent immunoassays (IA) has become widespread, although their metrological characteristics do not seem appropriate for quantifying low testosterone concentrations. The objective of this review is to analyse the methods for quantifying testosterone and to establish whether there is scientific evidence that justifies measuring it in patients with PC who undergo castration, through liquid chromatography attached to a mass spectrometry in tandem (LC-MSMS)...
March 2, 2017: Actas Urologicas Españolas
https://www.readbyqxmd.com/read/28230786/sex-specificity-of-mineralocorticoid-target-gene-expression-during-renal-development-and-long-term-consequences
#19
Laurence Dumeige, Caroline Storey, Lyvianne Decourtye, Melanie Nehlich, Christophe Lhadj, Say Viengchareun, Laurent Kappeler, Marc Lombès, Laetitia Martinerie
Sex differences have been identified in various biological processes, including hypertension. The mineralocorticoid signaling pathway is an important contributor to early arterial hypertension, however its sex-specific expression has been scarcely studied, particularly with respect to the kidney. Basal systolic blood pressure (SBP) and heart rate (HR) were measured in adult male and female mice. Renal gene expression studies of major players of mineralocorticoid signaling were performed at different developmental stages in male and female mice using reverse transcription quantitative PCR (RT-qPCR), and were compared to those of the same genes in the lung, another mineralocorticoid epithelial target tissue that regulates ion exchange and electrolyte balance...
February 21, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28193495/1%C3%AE-25-dihydroxyvitamin-d3-a-new-vitamin-d-metabolite-in-human-serum
#20
Steven Pauwels, Ivo Jans, Jaak Billen, Annemieke Heijboer, Annemieke Verstuyf, Geert Carmeliet, Chantal Mathieu, Miguel Maestro, Etienne Waelkens, Pieter Evenepoel, Roger Bouillon, Dirk Vanderschueren, Pieter Vermeersch
BACKGROUND: The measurement of 1α,25(OH)2D3 in human serum poses a true challenge as concentrations are very low and structurally similar metabolites can interfere. MATERIALS AND METHODS: During optimization of our in-house LC-MSMS method for serum 1α,25(OH)2D3 a previously co-eluting isobaric interference was separated. The isobar was identified as 1β,25(OH)2D3 by comparing retention time and fragmentation spectra to standards (other isobaric dihydroxylated vitamin D3 analogs)...
October 2017: Journal of Steroid Biochemistry and Molecular Biology
keyword
keyword
92196
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"