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https://www.readbyqxmd.com/read/28456451/high-sensitivity-determination-of-estrogens-in-fish-plasma-using-chemical-derivatization-upstream-uhplc-msms
#1
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
#2
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...
April 21, 2017: Protein Expression and Purification
https://www.readbyqxmd.com/read/28406359/enantioselective-analysis-of-chloramphenicol-residues-in-honey-samples-by-chiral-lc-msms-and-results-of-a-honey-survey
#3
Gerhard G Rimkus, Dirk Hoffmann
Chloramphenicol (CAP) is a broad-spectrum antibiotic used widely both in human and in veterinary medication. Since 1994 CAP is not authorised anymore for use in food-producing animals in the EU due to several adverse effects. A minimum required performance level (MRPL) 0.3 µg kg(-1) was established in 2003. 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/MSMS method is reported to identify and quantify the four CAP enantiomers at residue levels in honey samples...
April 13, 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
#4
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
#5
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
#6
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
#7
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
#8
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
#9
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)...
February 11, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28130543/monitoring-intravenous-abuse-of-methadone-or-buprenorphine-in-opiate-maintenance-treatment-omt-a-simple-and-fast-lc-ms-ms-method-for-the-detection-of-disaccharides-in-urine-samples
#10
Hilke Jungen, Hilke Andresen-Streichert, Alexander Müller, Stefanie Iwersen-Bergmann
The detection of disaccharides in urine is under investigation to act as a marker for intravenous abuse of disaccharide formulations, like liquid methadone with syrup (sucrose), methadone tablets (lactose and sucrose), or buprenorphine tablets (lactose). As the detection time in urine has not yet been investigated and a routine method for detecting disaccharides is still lacking, a study was performed to estimate the window of detection in urine after intravenous consumption of disaccharides. Furthermore, an analytical LC-MSMS method for the quantification of sucrose and lactose in urine was validated...
January 2017: Journal of Analytical Toxicology
https://www.readbyqxmd.com/read/28035926/pleiotropic-effect-of-human-apoe4-on-cerebral-ceramide-and-saturated-fatty-acid-levels
#11
Sandra den Hoedt, Carola I F Janssen, Giuseppe Astarita, Daniele Piomelli, Frank P J Leijten, Simone M Crivelli, Adrie J M Verhoeven, Helga E de Vries, Jochen Walter, Pilar Martinez-Martinez, Eric J G Sijbrands, Amanda J Kiliaan, Monique T Mulder
BACKGROUND: Apolipoprotein E (ApoE) is known for its role in lipid trafficking and the ɛ4 allele is a risk factor for late onset Alzheimer's disease (AD). Recently, aberrant ceramide and fatty acid (FA) levels have been implicated in AD. OBJECTIVE: To determine the specific effects of human ApoE4 (hE4) on cerebral ceramide and FA content during chow or a high fat/high cholesterol (HFHC) diet. METHODS: Cerebral ceramide and FA profiles were determined by LC-MSMS in 15-month-old female wild-type (WT), ApoE-knockout (E0), and hE4-knockin mice fed chow or a HFHC diet for 3 months...
December 30, 2016: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/27896924/detailed-tail-proteomic-analysis-of-axolotl-ambystoma-mexicanum-using-an-mrna-seq-reference-database
#12
Turan Demircan, Ilknur Keskin, Seda Nilgün Dumlu, Nilüfer Aytürk, Mahmut Erhan Avşaroğlu, Emel Akgün, Gürkan Öztürk, Ahmet Tarık Baykal
Salamander axolotl has been emerging as an important model for stem cell research due to its powerful regenerative capacity. Several advantages, such as the high capability of advanced tissue, organ, and appendages regeneration, promote axolotl as an ideal model system to extend our current understanding on the mechanisms of regeneration. Acknowledging the common molecular pathways between amphibians and mammals, there is a great potential to translate the messages from axolotl research to mammalian studies...
January 2017: Proteomics
https://www.readbyqxmd.com/read/27890823/assessment-of-thyroid-function-in-intensive-care-unit-patients-by-liquid-chromatography-tandem-mass-spectrometry-methods
#13
Kerry J Welsh, Brian R Stolze, Xiaolin Yu, Trisha R Podsiadlo, Lisa S Kim, Steven J Soldin
OBJECTIVES: Patients with non-thyroidal illness syndrome have many abnormalities in thyroid hormone tests. Such patients have medical comorbidities associated with low serum proteins and are on multiple medications that interfere with thyroid hormone measurement by immunoassay platforms. It is unknown if these thyroid hormone measurements reflect physiologic conditions or if they are artifacts of testing methodology. METHODS: Fifty patients were selected from the intensive care unit (ICU) from our institution...
April 2017: Clinical Biochemistry
https://www.readbyqxmd.com/read/27856525/microvilli-morphology-can-affect-efflux-active-p-glycoprotein-in-confluent-mdckii-nki_hmdr1-and-caco-2-cell-monolayers
#14
Zhou Meng, Sylvain Le Marchand, Deep Agnani, Matt Szapacs, Harma Ellens, Joe Bentz
From fits of drug transport kinetics across confluent MDCKII-hMDR1-NKI and Caco-2 cell monolayers we estimated the levels of efflux active P-glycoprotein (P-gp) in these two cell lines (companion paper, Meng at el., 2016a). In the present work, we compared the efflux active P-gp number to the total P-gp level, using LC/MSMS, and showed that in Caco-2 cells total P-gp is about 10-fold greater than efflux active P-gp, while in MDCKII-hMDR1-NKI cells these values are within 2-fold. We further visualized the microvilli in MDCKII-hMDR1-NKI and Caco-2 cells using three-dimensional structured illumination super-resolution microscopy and found that the microvilli in Caco-2 cells are taller and more densely packed than those in MDCK-NKI-hMDR1 cells...
November 16, 2016: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/27742727/intracellular-cd3-t-lymphocyte-teriflunomide-concentration-is-poorly-correlated-with-and-has-greater-variability-than-unbound-plasma-teriflunomide-concentration
#15
Ashley M Hopkins, Mahin Moghaddami, David J R Foster, Susanna M Proudman, Richard N Upton, Michael D Wiese
Leflunomide's active metabolite teriflunomide inhibits dihydro-oroate dehydrogenase, an enzyme essential to proliferation of T lymphocytes. As teriflunomide must reach the target site to have this effect, this study assessed the distribution of teriflunomide into T lymphocytes, as intracellular concentrations may be a superior response biomarker to plasma concentrations. CD3 MicroBeads (Miltenyi Biotec, Bergisch Gladbach, Germany) were used to extract CD3(+) T cells from the peripheral blood of patients with rheumatoid arthritis who were taking a stable dose of leflunomide...
January 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/27542000/serum-thyroglobulin-in-the-monitoring-of-differentiated-thyroid-cancer
#16
Carol Evans, Sarah Tennant, Petros Perros
Patients with differentiated thyroid cancer (DTC) usually have an excellent prognosis. Following surgical and radioiodine treatment to remove the cancer cells and suppressive doses of levothyroxine, long-term follow-up, including measurement of serum thyroglobulin (Tg) using a sensitive assay is required to detect recurrence. To interpret Tg results clinicians need to know the corresponding serum TSH concentration, have an appreciation of the clearance of Tg from patient serum following various interventions and the limitations of its measurement...
2016: Scandinavian Journal of Clinical and Laboratory Investigation. Supplementum
https://www.readbyqxmd.com/read/27498307/fast-method-for-simultaneous-quantification-of-tamoxifen-and-metabolites-in-dried-blood-spots-using-an-entry-level-lc-ms-ms-system
#17
Marie Tré-Hardy, Arnaud Capron, Marina Venzon Antunes, Rafael Linden, Pierre Wallemacq
The purpose of this study was to develop and validate a new liquid chromatography-tandem mass spectrometric (LC-MSMS) assay for the simultaneous quantification of tamoxifen (TAM) and its main therapeutically active metabolites, N-desmethyltamoxifen (NDT), 4-hydroxytamoxifen (4HT) and endoxifen (END) in dried blood spots. Ultrasound assisted methanolic extraction was used for TAM and metabolites extraction from dried blood spot. After evaporation and methanol reconstitution, the extract was injected into a LC-MSMS system...
November 2016: Clinical Biochemistry
https://www.readbyqxmd.com/read/27154681/validation-of-a-sensitive-lc-msms-method-for-chloronucleoside-analysis-in-biological-matrixes-and-its-applications
#18
Caroline Noyon, Cédric Delporte, Damien Dufour, Melissa Cortese, Alexandre Rousseau, Philippe Poelvoorde, Jean Nève, Luc Vanhamme, Karim Zouaoui Boudjeltia, Thierry Roumeguère, Pierre Van Antwerpen
Myeloperoxidase promotes several kinds of damage and is involved in the development of various diseases (as atherosclerosis and cancers). An example of these damage is the chlorination of nucleic acids, which is considered as a specific marker of the MPO activity on those acids. This study aimed to develop and validate a method to analyze oxidized and MPO-specific chlorinated nucleosides in biological matrixes (cells, tissues and plasma). Although a lot of methods to quantify oxidized or chlorinated nucleosides have already been established, none of them took into account all these derivatives together...
July 1, 2016: Talanta
https://www.readbyqxmd.com/read/26915341/a-novel-orellanine-containing-mushroom-cortinarius-armillatus
#19
Dahai Shao, Shusheng Tang, Rosanne A Healy, Paula M Imerman, Dwayne E Schrunk, Wilson K Rumbeiha
Orellanine (3,3',4,4'-tetrahydroxy-2,2'-bipyridine-1,1'-dioxide) is a tetrahydroxylated di-N-oxidized bipyridine compound. The toxin, present in certain species of Cortinarius mushrooms, is structurally similar to herbicides Paraquat and Diquat. Cortinarius orellanus and Cortinarius rubellus are the major orellanine-containing mushrooms. Cortinarius mushrooms are widely reported in Europe where they have caused human poisoning and deaths through accidental ingestion of the poisonous species mistaken for the edible ones...
May 2016: Toxicon: Official Journal of the International Society on Toxinology
https://www.readbyqxmd.com/read/26879528/is-measurement-of-tt3-by-immunoassay-reliable-at-low-concentrations-a-comparison-of-the-roche-cobas-6000-vs-lc-msms
#20
COMPARATIVE STUDY
Likhona Siphe Masika, Zhen Zhao, Steven John Soldin
OBJECTIVES: Thyroid dysfunction is a common medical condition affecting an estimated 30 million people in the US alone. Employing gold standard Liquid chromatography-tandem mass spectrometry (LC-MSMS) methods we have examined the extent of inaccuracy of immunoassay (IA) measurement for total T3 (TT3) at low, normal and high concentrations. DESIGN AND METHODS: 268 TT3 Roche Cobas 6000 immunoassay TT3 values (covering the low, normal, and high ranges) were compared with LC-MSMS results...
August 2016: Clinical Biochemistry
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