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https://www.readbyqxmd.com/read/28239974/simultaneous-monitoring-of-monoamines-amino-acids-nucleotides-and-neuropeptides-by-liquid-chromatography-tandem-mass-spectrometry-and-its-application-to-neurosecretion-in-bovine-chromaffin-cells
#1
Aneta Wojnicz, José Avendaño-Ortiz, Ricardo de Pascual, Lucía Ruiz-Pascual, Antonio G García, Ana Ruiz-Nuño
The primary functions of adrenal medullary chromaffin cells are the synthesis and storage in their chromaffin vesicles of the catecholamines noradrenaline (NA) and adrenaline (AD), and their subsequent release into the bloodstream by Ca(2+) -dependent exocytosis under conditions of fear or stress (fight or flight response). Several monoamines, nucleotides and opiates, such as leucine-enkephalin (LENK) and methionine-enkephalin (MENK), are also co-stored and co-released with the catecholamines. However, other neurotransmitters have not been studied in depth...
August 2016: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28239973/a-liquid-chromatography-atmospheric-pressure-photoionization-tandem-mass-spectrometric-lc-appi-ms-ms-method-for-the-determination-of-triterpenoids-in-medicinal-plant-extracts
#2
Luciana Assis Gobo, Carine Viana, Osmar Alves Lameira, Leandro Machado de Carvalho
An analytical method using liquid chromatography-atmospheric pressure photoionization tandem mass spectrometry with toluene as a dopant was developed for the determination of triterpenes in medicinal plant extracts. The 12 compounds determined have been shown to exhibit biological activity, such as gastroprotective, hepatoprotective, anti-inflammatory, antiviral and anti-tumor effects. The parameters of the atmospheric pressure photoionization interface were optimized to obtain the highest possible sensitivity for all of the compounds...
August 2016: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28239963/characterization-of-complex-heterogeneous-lipid-a-samples-using-hplc-ms-ms-technique-ii-structural-elucidation-of-non-phosphorylated-lipid-a-by-negative-ion-mode-tandem-mass-spectrometry
#3
Viktor Sándor, Anikó Kilár, Ferenc Kilár, Béla Kocsis, Ágnes Dörnyei
Non-phosphorylated lipid A species confer reduced inflammatory potential for the bacteria. Knowledge on their chemical structure and presence in bacterial pathogens may contribute to the understanding of bacterial resistance and activation of the host innate immune system. In this study, we report the fragmentation pathways of negatively charged, non-phosphorylated lipid A species under low-energy collision-induced dissociation conditions of an electrospray ionization quadrupole time-of-flight instrument. Charge-promoted consecutive and competitive eliminations of the acyl chains and cross-ring cleavages of the sugar residues were observed...
August 2016: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28239876/the-potential-of-volatile-organic-compounds-for-the-detection-of-active-disease-in-patients-with-ulcerative-colitis
#4
A Smolinska, A G L Bodelier, J W Dallinga, A A M Masclee, D M Jonkers, F-J van Schooten, M J Pierik
BACKGROUND: To optimise treatment of ulcerative colitis (UC), patients need repeated assessment of mucosal inflammation. Current non-invasive biomarkers and clinical activity indices do not accurately reflect disease activity in all patients and cannot discriminate UC from non-UC colitis. Volatile organic compounds (VOCs) in exhaled air could be predictive of active disease or remission in Crohn's disease. AIM: To investigate whether VOCs are able to differentiate between active UC, UC in remission and non-UC colitis...
February 26, 2017: Alimentary Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/28239739/occurrence-of-veterinary-antibiotics-in-swine-manure-from-large-scale-feedlots-in-zhejiang-province-china
#5
Hua Wang, Yixuan Chu, Chengran Fang
The occurrence and distribution of five sulfonamides and three tetracyclines in swine manure sampled from large-scale feedlots in different areas of Zhejiang Province, China were detected using solid-phase extraction and high-performance liquid chromatography. All eight test antibiotics were detected in most of the manure samples. The dominant antibiotics in swine manure were sulfadiazine, sulfamerazine, sulfadimidine, tetracycline, and chlortetracycline. The maximum concentration of residual antibiotic reached up to 57...
February 27, 2017: Bulletin of Environmental Contamination and Toxicology
https://www.readbyqxmd.com/read/28239064/theoretical-aspects-of-triacylglycerin-positional-isomer-separation-on-reverse-phase-high-performance-liquid-chromatography
#6
Tsugihiko Hirano, Keiichi Yokochi, Koretaro Takahashi
The purpose of the present study is to bear our hypothesis and to make a profound discussion on the theoretical aspects of triacylglycerin (TG) positional isomer separation on reverse phase high performance liquid chromatography (HPLC). Authentic triacid TG positional isomers and authentic diacid TG positional isomers were injected to a monomeric and polymeric HPLC. Relationship between TG molecular structure and those elution profiles were carefully analyzed. In polymeric column, thickness of the ODS chain is high compared to monomeric column...
February 24, 2017: Journal of Oleo Science
https://www.readbyqxmd.com/read/28239063/fatty-acid-and-lipid-class-composition-of-the-microalga-phaeodactylum-tricornutum
#7
Yu-Hong Yang, Lei Du, Masashi Hosokawa, Kazuo Miyashita, Yume Kokubun, Hisayoshi Arai, Hiroyuki Taroda
n-3 Polyunsaturated fatty acids (PUFAs) are essential for the prevention and/or risk reduction of some diseases, including cardiovascular diseases and cancer. Therefore, PUFAs-rich marine microalgae have received considerable research attention. The diatom Phaeodactylum tricornutum, a rich source of lipids and fucoxanthin, has commercial applications in the food and pharmaceutical industries. In this study, the lipid class composition and fatty acid distribution in P. tricornutum under high-density and scale-up cultivation were investigated by thin-layer chromatography and gas chromatography...
February 24, 2017: Journal of Oleo Science
https://www.readbyqxmd.com/read/28238935/tryptophan-and-purine-metabolites-are-consistently-upregulated-in-the-urinary-metabolome-of-patients-diagnosed-with-gestational-diabetes-mellitus-throughout-pregnancy-a-longitudinal-metabolomics-study-of-chinese-pregnant-women-part-2
#8
Kai P Law, Ting-Li Han, Xun Mao, Hua Zhang
BACKGROUND: Gestational diabetes mellitus (GDM) is a pathological state of glucose intolerance associated with adverse pregnancy outcomes and an increased risk of developing maternal type 2 diabetes later in life. The mechanisms underlying GDM development are not fully understood. We examined the pathophysiology of GDM through comprehensive metabolic profiling of maternal urine, using participants from a longitudinal cohort of normal pregnancies and pregnancies complicated by GDM. METHODS: Based on ultra-performance liquid chromatography/hybrid quadrupole time-of-flight mass spectrometry, an untargeted metabolomics study was performed to explore the differences in the urinary metabolome of GDM cases and healthy controls over the course of pregnancy...
February 23, 2017: Clinica Chimica Acta; International Journal of Clinical Chemistry
https://www.readbyqxmd.com/read/28238810/defect-in-dermatan-sulfate-in-urine-of-patients-with-ehlers-danlos-syndrome-caused-by-a-chst14-d4st1-deficiency
#9
Shuji Mizumoto, Tomoki Kosho, Atsushi Hatamochi, Tomoko Honda, Tomomi Yamaguchi, Nobuhiko Okamoto, Noriko Miyake, Shuhei Yamada, Kazuyuki Sugahara
PURPOSE: Dermatan sulfate (DS) plays a number of roles in a wide range of biological activities such as cell signaling and tissue morphogenesis through interactions with various extracellular matrix proteins including collagen. Mutations in the carbohydrate sulfotransferase 14 gene (CHST14) encoding CHST14/dermatan 4-O-sulfotransferase-1 (D4ST1), which is responsible for the biosynthesis of DS, cause a recently delineated form of Ehlers-Danlos syndrome (EDS, musculocontractural type 1), an autosomal recessive connective tissue disorder characterized by congenital malformations (specific craniofacial features, and congenital multiple contractures) and progressive fragility-related complications (skin hyperextensibility, bruisability, and fragility with atrophic scars; recurrent dislocations; progressive talipes or spinal deformities; and large subcutaneous hematomas)...
February 23, 2017: Clinical Biochemistry
https://www.readbyqxmd.com/read/28238809/in-situ-protein-determination-to-monitor-contamination-in-a-centrifugal-partition-chromatograph
#10
Feriel Bouiche, Karine Faure
Centrifugal partition chromatography (CPC) works with biphasic liquid systems including aqueous two-phase systems. Metallic rotors are able to retain an aqueous stationary phase able to purify proteins. But the adhesion of proteins to solid surface may pose a cross-contamination risk during downstream processes. So it is of utmost importance to ensure the cleanliness of the equipment and detect possible protein contamination in a timely manner. Thereby, a direct method that allows the determination of the effective presence of proteins and the extent of contamination in the metallic CPC rotors was developed...
February 23, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28238790/multifunctional-liposomes-interact-with-abeta-in-human-biological-fluids-therapeutic-implications-for-alzheimer-s-disease
#11
Elisa Conti, Maria Gregori, Isabella Radice, Fulvio Da Re, Denise Grana, Francesca Re, Elisa Salvati, Massimo Masserini, Carlo Ferrarese, Chiara Paola Zoia, Lucio Tremolizzo
The accumulation of extracellular amyloid beta (Abeta42) both in brain and in cerebral vessels characterizes Alzheimer's disease (AD) pathogenesis. Recently, the possibility to functionalize nanoparticles (NPs) surface with Abeta42 binding molecules, making them suitable tools for reducing Abeta42 burden has been shown effective in models of AD. Aim of this work consisted in proving that NPs might be effective in sequestering Abeta42 in biological fluids, such as CSF and plasma. This demonstration is extremely important considering that these Abeta42 pools are in continuum with the brain parenchyma with drainage of Abeta from interstitial brain tissue to blood vessel and plasma...
February 23, 2017: Neurochemistry International
https://www.readbyqxmd.com/read/28238733/fragmentation-of-the-crispr-cas-type-i-b-signature-protein-cas8b
#12
Hagen Richter, Judith Rompf, Julia Wiegel, Kristina Rau, Lennart Randau
BACKGROUND: CRISPR arrays are transcribed into long precursor RNA species, which are further processed into mature CRISPR RNAs (crRNAs). Cas proteins utilize these crRNAs, which contain spacer sequences that can be derived from mobile genetic elements, to mediate immunity during a reoccurring virus infection. Type I CRISPR-Cas systems are defined by the presence of different Cascade interference complexes containing large and small subunits that play major roles during target DNA selection...
February 23, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28238459/linking-sources-to-early-effects-by-profiling-urine-metabolome-of-residents-living-near-oil-refineries-and-coal-fired-power-plants
#13
Chi-Hsin Sally Chen, Tzu-Hsuen Yuan, Ruei-Hao Shie, Kuen-Yuh Wu, Chang-Chuan Chan
BACKGROUND: This study aims at identifying metabolic changes linking external exposure to industrial air toxics with oxidative stress biomarkers. METHODS: We classified 252 study subjects as 111 high vs. 141 low exposure subjects by the distance from their homes to the two main emission sources, oil refineries and coal-fired power plants. We estimated individual's external exposure to heavy metals and polycyclic aromatic hydrocarbons (PAHs) by dispersion and kriging models, respectively...
February 23, 2017: Environment International
https://www.readbyqxmd.com/read/28238434/formation-of-known-and-unknown-disinfection-by-products-from-natural-organic-matter-fractions-during-chlorination-chloramination-and-ozonation
#14
Chunmei Li, Donghong Wang, Xiong Xu, Zijian Wang
Natural organic matter (NOM) is the main precursor of disinfection by-products (DBPs) formed during drinking water treatment processes. Previous studies of the relationships between DBP formation and NOM fractionation have mainly been focused on currently regulated DBPs and a few certain emerging DBPs. In this work, the Suwannee River NOM solution was fractionated into groups with different hydrophobicities using DAX-8 resins, and volatile and semi-volatile DBPs formed during the chlorination, chloramination and ozonation of the NOM fractions were examined by a nontargeted screening of comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry procedure...
February 23, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28238428/sensitive-screening-of-abused-drugs-in-dried-blood-samples-using-ultra-high-performance-liquid-chromatography-ion-booster-quadrupole-time-of-flight-mass-spectrometry-uhplc-ib-qtof-ms
#15
Divyabharathi Chepyala, I-Lin Tsai, Hsiao-Wei Liao, Guan-Yuan Chen, Hsi-Chun Chao, Ching-Hua Kuo
An increased rate of drug abuse is a major social problem worldwide. The dried blood spot (DBS) sampling technique offers many advantages over using urine or whole blood sampling techniques. This study developed a simple and efficient ultra-high-performance liquid chromatography-ion booster-quadrupole time-of-flight mass spectrometry (UHPLC-IB-QTOF-MS) method for the analysis of abused drugs and their metabolites using DBS. Fifty-seven compounds covering the most commonly abused drugs, including amphetamines, opioids, cocaine, benzodiazepines, barbiturates, and many other new and emerging abused drugs, were selected as the target analytes of this study...
February 21, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28238427/development-of-a-non-radiolabeled-glucosyltransferase-activity-assay-for-c-difficile-toxin-a-and-b-using-ultra-performance-liquid-chromatography
#16
John W Loughney, Catherine Lancaster, Colleen E Price, Van M Hoang, Sha Ha, Richard R Rustandi
Clostridium difficile infection (CDI) is the leading cause of gastroenteritis-associated death in the United States. The major virulent factors of C. difficile are toxin A (TcdA) and toxin B (TcdB). Toxicity is mediated by the glucosyltransferase domains on TcdA and TcdB wherein a glucose is transferred from UDP-glucose to Ras homolog family member A (RhoA) receptor. This modification results in disruption of critical cell signaling events. Vaccination against these toxins is considered the best way to combat the CDI...
January 31, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28238426/editorial-to-extended-nano-chromatography-by-hisashi-shimizu-adelina-smirnova-kazuma-mawatari-takehiko-kitamori
#17
EDITORIAL
Marja-Liisa Riekkola
No abstract text is available yet for this article.
February 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28238425/reliable-screening-and-confirmation-of-156-multi-class-illegal-adulterants-in-dietary-supplements-based-on-extracted-common-ion-chromatograms-by-ultra-high-performance-liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry
#18
Eun Hye Kim, Hee Seung Seo, Nam Yong Ki, Na-Hyun Park, Wonwoong Lee, Jung Ah Do, Sungkwan Park, Sun Young Baek, Bongjin Moon, Han Bin Oh, Jongki Hong
An analytical method for the reliable screening and confirmation of 156 illegal drugs (58 erectile dysfunction drugs, 49 synthetic steroids, 26 anabolic steroids, and 23 anti-histamine drugs) in supplementary diets using ultra-high-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) was developed. Various types of supplements (liquid, capsule, powder, pill and tablet) with complicated matrices were pretreated by simple liquid-liquid extraction. The wide scope of 156 target compounds was effectively determined within 15min in the positive ion mode, detecting the compounds at a sub-ppb level...
February 20, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28238325/elimination-of-n-o-bis-trimethylsilyl-trifluoroacetamide-interference-by-base-treatment-in-derivatization-gas-chromatography-mass-spectrometry-determination-of-parts-per-billion-of-alcohols-in-a-food-additive
#19
Koudi Zhu, Binghe Gu, Michale Kerry, Markus Mintert, Jim Luong, Matthias Pursch
A novel base treatment followed by liquid-liquid extraction was developed to remove the interference of excess derivatization reagent BSTFA [N,O-Bis(trimethylsilyl)trifluoroacetamide] and its byproducts for trace determination of 1-chloro-2-propanol and 2-chloro-1-propanol in a food additive. The corresponding trimethylsilyl derivatives were analyzed by gas chromatography mass spectrometry (GC/MS) detection in selective ion monitoring mode. Due to a large volume splitless injection needed for achieving the required sensitivity, excess BSTFA in the derivatization sample solution interfered with the trimethylsilyl derivatives of the analytes of interest, making their quantitation not attainable...
February 14, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28238323/design-of-strategies-to-study-the-metabolic-profile-of-highly-polar-compounds-in-plasma-by-reversed-phase-liquid-chromatography-high-resolution-mass-spectrometry
#20
Elena Sánchez-López, Antonio L Crego, María Luisa Marina
Amino acids and related compounds are paramount analytes which are involved in numerous metabolic pathways. Most of these compounds are unable to be retained on Liquid Chromatography with Reversed-Phase stationary phases due to their high hydrophilic character. An interesting strategy is to reduce their polarity through their derivatization with a labelling reagent, such as the commercially available 9-fluorenylmethyloxycarbonyl (FMOC) which forms stable complexes with primary and secondary amine moieties rapidly...
February 15, 2017: Journal of Chromatography. A
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