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https://www.readbyqxmd.com/read/28735472/assessment-of-soils-contamination-with-veterinary-antibiotic-residues-in-northern-poland-using-developed-mae-spe-lc-ms-ms-methods
#1
Paulina Łukaszewicz, Jolanta Kumirska, Anna Białk-Bielińska, Joanna Dołżonek, Piotr Stepnowski
Among the wide range of compounds reaching the soil are the veterinary antimicrobials. Since no regulations regarding acceptable levels of drug concentrations in the environment exist, monitoring tests, particularly concerning soils, are carried out very rarely. This study presents a preliminary assessment of the contamination of agricultural soils in Northern Poland with seven antimicrobial veterinary medicines which has never been carried out before. Veterinary drugs were detected in 54% of the examined soil samples; the most commonly detected drugs were sulfonamides and trimethoprim...
July 22, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28735404/porous-graphitic-carbon-liquid-chromatography-mass-spectrometry-analysis-of-drought-stress-responsive-raffinose-family-oligosaccharides-in-plant-tissues
#2
Tiago F Jorge, Maria H Florêncio, Carla António
Drought is a major limiting factor in agriculture and responsible for dramatic crop yield losses worldwide. The adjustment of the metabolic status via accumulation of drought stress-responsive osmolytes is one of the many strategies that some plants have developed to cope with water deficit conditions. Osmolytes are highly polar compounds, analysis of whcih is difficult with typical reversed-phase chromatography. Porous graphitic carbon (PGC) has shown to be a suitable alternative to reversed-phase stationary phases for the analysis of highly polar compounds typically found in the plant metabolome...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28735223/isomeric-separation-and-quantitation-of-di-2-ethylhexyl-trimellitates-and-mono-2-ethylhexyl-trimellitates-in-blood-by-lc-ms-ms
#3
Christine Höllerer, Johannes Müller, Thomas Göen, Elisabeth Eckert
A new and fast HPLC-method for the simultaneous determination of tri-(2-ethylhexyl) trimellitate (TOTM or TEHTM), its diesters 2,4-di-(2-ethylhexyl) trimellitate (2,4-DEHTM), 1,4-di-(2-ethylhexyl) trimellitate (1,4-DEHTM), 1,2-di-(2-ethylhexyl) trimellitate (1,2-DEHTM) and monoesters 1-mono-(2-ethylhexyl) trimellitate (1-MEHTM), 2-mono-(2-ethylhexyl) trimellitate (2-MEHTM) and 4-mono-(2-ethylhexyl) trimellitate (4-MEHTM) together with di-(2-ethylhexyl) phthalate (DEHP) and its primary metabolite mono-(2-ethylhexyl) phthalate (MEHP) in blood was developed and validated...
July 10, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28734989/hydroxyvitamin-d-assays-an-historical-perspective-from-deqas
#4
G D Carter, J Berry, R Durazo-Arvizu, E Gunter, G Jones, J Jones, H L J Makin, P Pattni, C T Sempos, P Twomey, E L Williams, S A Wise
Recent years have seen a substantial increase in demand for 25-hydroxyvitamin D (25-OHD) assays. DEQAS (the Vitamin D External Quality Assessment Scheme) has been monitoring the performance of these assays since 1989. The first DEQAS distribution was in June 1989 and results were submitted by 13 laboratories in the UK, two of which used HPLC/UV; the rest used ligand binding assays with a tritium tracer. Inter-laboratory CVs (ALTM) ranged from 29.3% (42.7 nmol/L) to 53.7% (20.0 nmol/L). Currently the scheme has participants in 56 countries using 30 methods or variants of methods...
July 19, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28734983/dietary-administration-of-tetrodotoxin-and-its-putative-biosynthetic-intermediates-to-the-captive-reared-non-toxic-japanese-fire-bellied-newt-cynops-pyrrhogaster
#5
Yuta Kudo, Chikafumi Chiba, Keiichi Konoki, Yuko Cho, Mari Yotsu-Yamashita
The origin of tetrodotoxin (TTX) in amphibians has long been disputed. In this study, TTX and its putative biosynthetic intermediates or shunt compounds (4,9-anhydro-10-hemiketal-5-deoxyTTX and Cep-242) were dietary administered to the captive-reared, non-toxic Japanese fire-bellied newt, Cynops pyrrhogaster. After 4 weeks, the ingested compounds were detected mainly in the newt body using liquid chromatography-mass spectrometry (LC-MS), while these compounds were not converted into other TTX analogues in newts...
July 19, 2017: Toxicon: Official Journal of the International Society on Toxinology
https://www.readbyqxmd.com/read/28734607/impact-of-instrument-and-column-parameters-on-high-throughput-liquid-chromatography-performance
#6
Martin Gilar, Thomas S McDonald, Fabrice Gritti
The speed and separation performance of high-throughput liquid chromatography (HT LC) was investigated. We evaluated the contributions of various experimental parameters to the total analysis cycle time, including column length (column void time), gradient delay, flow rate, auto-sampler (A/S) speed, and software related delays. The best case injection-to-injection cycle time of 22s was achieved using 12s gradient time and 2.1×20mm columns packed with 1.7μm C18 particles. The total 22s analytical duty cycle consisted of 2...
July 11, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28734369/systematic-comparison-of-exosomal-proteomes-from-human-saliva-and-serum-for-the-detection-of-lung-cancer
#7
Yan Sun, Sha Liu, Zhi Qiao, Zhi Shang, Zhijun Xia, Xiaomin Niu, Liqiang Qian, Yan Zhang, Liuyin Fan, Cheng-Xi Cao, Hua Xiao
Circulating tumor exosomes harbor plenty of cancer biological information, which have emerged as promising targets for cancer early detection and diagnosis. Human serum and saliva are unique diagnostic body fluids, which contain numerous circulating exosomes. It is necessary to establish standardized isolation method and compare their proteome profiling for translational medicine. High abundant proteins in these body fluids were removed before exosomes isolation and obtained exosomes were further confirmed by morphology analysis and surface biomarker test...
August 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28734350/dried-urine-spots-a-novel-sampling-technique-for-comprehensive-lc-ms-n-drug-screening
#8
Julian A Michely, Markus R Meyer, Hans H Maurer
Dried matrix spot (DMS) technique as alternative sampling strategy, especially dried urine spots (DUS), might be an alternative for drug screening. So far only particular drugs or drug classes were covered in DMS screenings. Therefore, workup of DUS for a broad comprehensive library-based LC-MS(n) screening was developed. It consisted of enzymatic on-spot deconjugation followed by liquid extraction and LC-MS(n) analysis. This workup was compared to established urine precipitation (UP) and validated according to international guidelines for qualitative approaches, using exemplary compounds of several drug classes (antidepressants, benzodiazepines, cardiovascular drugs, neuroleptics, opioids, stimulants, etc...
August 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28734271/development-and-validation-of-sensitive-lc-ms-ms-method-for-the-quantification-of-suvn-502-and-its-metabolite-and-its-application-for-first-in-human-pharmacokinetic-study
#9
Ramakrishna Nirogi, Devender Reddy Ajjala, Raghupathi Aleti, Lakshmiprasanna Rayapati, Hanumanth Rao Pantangi, Rajesh Kumar Boggavarapu, Naga Surya Prakash Padala
A sensitive and rapid LC-MS/MS method was developed and validated for the quantification of SUVN-502 and M1 of SUVN-502, a 5-HT6 receptor antagonist for the treatment of dementia associated with Alzheimer's disease. Following solid-phase extraction, SUVN-502 and M1 of SUVN-502 and IS were eluted with 10mM ammonium acetate (pH 4.0) and acetonitrile using a rapid gradient program on reverse phase column. Multiple reaction monitoring mode was used to monitor the respective transitions of m/z 478.2→377.7 for SUVN-502 and m/z 464...
April 14, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28734159/development-of-a-lc-ms-ms-method-for-the-determination-of-ckd-712-in-rat-plasma-application-to-a-pharmacokinetic-study-in-rats
#10
Jung-Woo Chae, Hwi-Yeol Yun, Han Young Eom, Eun Ju Jeong, Tae-Sung Koo, Kwang-Il Kwon, Jong-Hwa Lee
CKD-712 is a potential treatment for sepsis, as it exhibits protective effects against lipopolysaccharide-mediated platelet aggregation, inducible nitric oxide synthase expression, and cecum-ligation puncture-induced septic mortality in mice. In this study, we develop a rapid and sensitive LC-MS/MS method for determining CKD-712 in rat plasma. CKD-712 and papaverine hydrochloride (an internal standard) were analyzed using an LC-MS/MS system consisting of an Agilent HPLC system (HP-1100) equipped with an Atlantis HILIC Silica (2...
July 8, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28733235/determination-of-fumonisin-b1-levels-in-body-fluids-and-hair-from-piglets-fed-fumonisin-b1-contaminated-diets
#11
Pollyana C M C Souto, Alessandra V Jager, Fernando G Tonin, Tânia Petta, Mayra C Di Gregório, Anne-Marie Cossalter, Philippe Pinton, Isabelle P Oswald, George E Rottinghaus, Carlos A F Oliveira
The levels of fumonisin B1 (FB1) residues in plasma, urine, feces and hair from 24 piglets fed FB1-contaminated diets containing 3.1, 6.1 or 9.0 μg FB1.g(-1) for 28 days were determined using liquid chromatography coupled to mass spectrometry (LC-MS/MS). The levels of FB1 in plasma, urine, feces and pooled hair (n = 3) samples varied from 0.15-1.08 μg.L(-1), 16.09-75.01 μg.L(-1), 1.87-13.89 μg.g(-1) and 2.08-8.09 ng.g(-1), respectively. Significant correlations (r = 0.808-0.885; P < 0.001; N = 18) were found between FB1 intake and plasma FB1 on days 7, 14, 21 and 28...
July 18, 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/28733212/the-peroxyl-radical-induced-oxidation-of-escherichia-coli-ftsz-and-its-single-tryptophan-mutant-y222w-modifies-specific-side-chains-generates-protein-cross-links-and-affects-biological-function
#12
Elizabeth Escobar-Álvarez, Fabian Leinisch, Gissela Araya, Octavio Monasterio, Lasse G Lorentzen, Eduardo Silva, Michael J Davies, Camilo López-Alarcón
FtsZ (filamenting temperature-sensitive mutant Z) is a key protein in bacteria cell division. The wild-type Escherichia coli FtsZ sequence (FtsZwt) contains three tyrosine (Tyr, Y) and sixteen methionine (Met, M) residues. The Tyr at position 222 is a key residue for FtsZ polymerization. Mutation of this residue to tryptophan (Trp, W; mutant Y222W) inhibits GTPase activity resulting in an extended time in the polymerized state compared to FtsZwt. Protein oxidation has been highlighted as a determinant process for bacteria resistance and consequently oxidation of FtsZwt and the Y222W mutant, by peroxyl radicals (ROO•) generated from AAPH (2,2'-azobis(2-methylpropionamidine) dihydrochloride) was studied...
July 18, 2017: Free Radical Biology & Medicine
https://www.readbyqxmd.com/read/28732012/multi-approach-metabolomics-analysis-and-artificial-simplified-phytocomplexes-reveal-cultivar-dependent-synergy-between-polyphenols-and-ascorbic-acid-in-fruits-of-the-sweet-cherry-prunus-avium-l
#13
Mauro Commisso, Martino Bianconi, Flavia Di Carlo, Stefania Poletti, Alessandra Bulgarini, Francesca Munari, Stefano Negri, Matteo Stocchero, Stefania Ceoldo, Linda Avesani, Michael Assfalg, Gianni Zoccatelli, Flavia Guzzo
Fruits of the sweet cherry (Prunus avium L.) accumulate a range of antioxidants that can help to prevent cardiovascular disease, inflammation and cancer. We tested the in vitro antioxidant activity of 18 sweet cherry cultivars collected from 12 farms in the protected geographical indication region of Marostica (Vicenza, Italy) during two growing seasons. Multiple targeted and untargeted metabolomics approaches (NMR, LC-MS, HPLC-DAD, HPLC-UV) as well as artificial simplified phytocomplexes representing the cultivars Sandra Tardiva, Sandra and Grace Star were then used to determine whether the total antioxidant activity reflected the additive effects of each compound or resulted from synergistic interactions...
2017: PloS One
https://www.readbyqxmd.com/read/28731694/the-foliar-desiccators-glyphosate-carfentrazone-and-paraquat-affect-the-technological-and-chemical-properties-of-cowpea-grains
#14
Igor da Silva Lindemann, Gustavo Heinrich Lang, Jessica Fernanda Hoffmann, Cesar Valmor Rombaldi, Mauricio de Oliveira, Moacir Cardoso Elias, Nathan Levien Vanier
The effects of the use of glyphosate (GLY), glyphosate plus carfentrazone (GLY/CAR), and paraquat (PAR) as plant desiccators on the technological and chemical properties of cowpea grains were investigated. All studied desiccants provided lower cooking time to freshly harvested cowpea. However, the coat color of PAR- and GLY/CAR-treated cowpea was reddish than control treatment. Principal component analysis (PCA) from liquid chromatography-mass spectrometry (LC-MS) data sets showed a clear distinction among cowpea from the different treatments...
July 21, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28731579/residual-dynamic-and-risk-assessment-of-dimethomorph-in-swiss-chard-grown-in-two-different-sites
#15
Md Humayun Kabir, A M Abd El-Aty, Md Musfiqur Rahman, Hyung Suk Chung, Han Sol Lee, Mi-Ra Kim, Byung-Joon Chang, Jing Wang, Ho-Chul Shin, Jae-Han Shim
Residue analysis of dimethomorph in Swiss chard cultivated at two different locations under greenhouse conditions was conducted using high-performance liquid chromatography-ultraviolet detector (HPLC-UVD) and confirmed by tandem mass spectrometry (LC-MS/MS). The randomly collected samples (over 14 days) were extracted with acetonitrile and purified using a Florisil solid-phase extraction (SPE) cartridge. Linearity over a concentration range of 0.05-50.0 mg/L had an excellent coefficient of determination (R(2) ) = 0...
July 21, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28731312/gentiana-kurroo-royle-attenuates-the-metabolic-aberrations-in-diabetic-rats-swertiamarin-swertisin-and-lupeol-being-the-possible-bioactive-principles
#16
Khalid Ghazanfar, Khan Mubashir, Showkat A Dar, Tazeen Nazir, Iqra Hameed, Bashir A Ganai, Seema Akbar, Akbar Masood
Background Gentiana kuroo Royle is a medicinally important plant of north-western Himalayas used for various ailments. In the present study, the plant extracts were investigated for the antidiabetic effects in streptozotocin-induced diabetic rats. Methods The impact of the extracts on serum glucose levels of diabetic rats was compared with reference drug - glibenclamide-treated diabetic rats. Streptozotocin injection was used to induce diabetes in fasted rats. Various biochemical, physiological and histopathological parameters in diabetic rats were observed for assessing the antidiabetic activity...
April 29, 2017: Journal of Complementary & Integrative Medicine
https://www.readbyqxmd.com/read/28730944/integrating-bioassays-and-analytical-chemistry-as-an-improved-approach-to-support-safety-assessment-of-food-contact-materials
#17
Julien Veyrand, Maricel Marin-Kuan, Claudine Bezencon, Nancy Frank, Violaine Guérin, Sander Koster, Hélia Latado, Julie Mollergues, Amaury Patin, Dominique Piguet, Patrick Serrant, Jesus Varela, Benoît Schilter
Food contact materials (FCM) contain chemicals which can migrate into food and result in human exposure. Although it is mandatory to ensure that migration does not endanger human health, there is still no consensus on how to pragmatically assess the safety of FCM since traditional approaches would require extensive toxicological and analytical testing which are expensive and time consuming. Recently, the combination of bioassays, analytical chemistry and risk assessment has been promoted as a new paradigm to identify toxicologically relevant molecules and address safety issues...
July 21, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28730706/chromatographic-profiles-of-tryptophan-and-kynurenine-enantiomers-derivatized-with-s-4-3-isothiocyanatopyrrolidin-1-yl-7-n-n-dimethylaminosulfonyl-2-1-3-benzoxadiazole-using-lc-ms-ms-on-a-triazole-bonded-column
#18
Hideaki Iizuka, Takahiro Harashima, Shuhei Takahashi, Ryosuke Kuwabara, Yoko Naito, Tatsuya Sakamoto, Mayu Onozato, Hideaki Ichiba, Takeshi Fukushima
d- and l-Tryptophan (Trp) and d- and l-kynurenine (KYN) were derivatized with a chiral reagent, (S)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole (DBD-PyNCS), and were separated enantiomerically by high-performance liquid chromatography (HPLC) equipped with a triazole-bonded column (Cosmosil HILIC) using tandem mass spectrometric (MS/MS) detection. Effects of column temperature, salt (HCO2 NH4 ) concentration, and pH of the mobile phase in the enantiomeric separation, followed by MS detection of (S)-DBD-PyNCS-d,l-Trp and -d,l-KYN, were investigated...
July 21, 2017: Chirality
https://www.readbyqxmd.com/read/28730564/a-new-approach-to-assess-occupational-exposure-to-airborne-fungal-contamination-and-mycotoxins-of-forklift-drivers-in-waste-sorting-facilities
#19
Carla Viegas, Tiago Faria, Ana Cebola de Oliveira, Liliana Aranha Caetano, Elisabete Carolino, Anita Quintal-Gomes, Magdalena Twarużek, Robert Kosicki, Ewelina Soszczyńska, Susana Viegas
The waste management industry is an important employer, and exposure of waste-handling workers to microorganisms is considered an occupational health problem. Besides fungal contamination, it is important to consider the co-occurrence of mycotoxins in this setting. Forklifts with closed cabinet and air conditioner are commonly used in waste industry to transport waste and other products within the facilities, possibly increasing the risk of exposure under certain conditions. The aim of this study was to assess the fungal contamination and mycotoxin levels in filters from the air conditioning system of forklift cabinets, as an indicator to assess occupational exposure of the drivers working in a waste sorting facility...
July 20, 2017: Mycotoxin Research
https://www.readbyqxmd.com/read/28730494/deconstructing-the-metabolic-networks-of-oncogenic-signaling-using-targeted-liquid-chromatography-tandem-mass-spectrometry-lc-ms-ms
#20
George Poulogiannis
Metabolic reprogramming is recognized as an emerging hallmark of oncogenic signaling and cancer development. Hence the need to identify novel quantitative analytical platforms for studying metabolism in vitro and in vivo has dramatically increased. Here, we describe the experimental workflow for a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach involving positive/negative ion switching to analyze >250 metabolites of central carbon metabolism, nucleotides, and amino acids.
2017: Methods in Molecular Biology
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