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"Mass spectrometry"

Uzochukwu C Ugochukwu, Alfred Ochonogor, Chika M Jidere, Chizoba Agu, Frida Nkoloagu, John Ewoh, Virginia U Okwu-Delunzu
In this study, the human and livestock (cattle) health risks of exposure to polycyclic aromatic hydrocarbons (PAHs) in a wetland of Obuaku, Abia State Nigeria contaminated by hydrocarbon spill due to incidents of hydrocarbon theft and pipeline vandalization were assessed. Gas chromatography-flame ionization detector and gas chromatography-mass spectrometry were employed in analyzing the TPH and PAHs respectively. The contaminated soil was delineated into sub-locations AOC-1, AOC-2, AOC-3, AOC-4, AOC-5 and AOC-6 to reflect the discrete patches (areas) of the contaminated site and for effective planning of remedial actions...
March 13, 2018: Environment International
Davy Guillarme, Vincent Desfontaine, Sabine Heinisch, Jean-Luc Veuthey
Mass spectrometry (MS) is considered today as one of the most popular detection methods, due to its high selectivity and sensitivity. In particular, this detector has become the gold standard for the analysis of complex mixtures such as biological samples. The first successful SFC-MS hyphenation was reported in the 80's, and since then, several ionization sources, mass analyzers and interfacing technologies have been combined. Due to the specific physicochemical properties and compressibility of the SFC mobile phase, directing the column effluent into the ionization source is more challenging than in LC...
March 7, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Mingfei Zeng, Huachuan Cao
Short chain fatty acids (SCFA) and ketone bodies recently emerged as important physiological relevant metabolites because of their association with microbiota, immunology, obesity and other metabolic states. They were commonly analyzed by GC-MS with long run time and laborious sample preparation. In this study we developed a novel LC-MS/MS method using fast derivatization coupled with liquid-liquid extraction to detect SCFA and ketone bodies in plasma and feces. Several different derivatization reagents were evaluated to compare the efficiency, the sensitivity and chromatographic separation of structural isomers...
March 8, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Aniko Krumbholz, Martin Schönfelder, Hande Hofmann, Detlef Thieme
BACKGROUND: The endogenous glucocorticosteroid cortisol (F) and its metabolite cortisone (E) are known to be involved in stress adaption and anti-inflammatory and immune regulatory effects. The ratios of F to E in the matrices serum, hair and saliva are different. The shift of this ratio by the enzyme activity of 11β-hydroxysteroid-dehydrogenase, which inactivates cortisol, was often discussed. The aim of our study was to calculate the contribution of the plasma protein binding (PPB) to this shift...
February 26, 2018: Forensic Science International
Samuel Mesihää, Ilpo Rasanen, Ilkka Ojanperä
Gas chromatography (GC) hyphenated with nitrogen chemiluminescence detection (NCD) and quadrupole time-of-flight mass spectrometry (QTOFMS) was applied for the first time to the quantitative analysis of new psychoactive substances (NPS) in urine, based on the N-equimolar response of NCD. A method was developed and validated to estimate the concentrations of three metabolites of the common stimulant NPS α-pyrrolidinovalerophenone (α-PVP) in spiked urine samples, simulating an analysis having no authentic reference standards for the metabolites and using the parent drug instead for quantitative calibration...
February 27, 2018: Forensic Science International
María Victoria Repetto, Matthew J Winters, Alan Bush, Wolfgang Reiter, David Maria Hollenstein, Gustav Ammerer, Peter M Pryciak, Alejandro Colman-Lerner
We report an unanticipated system of joint regulation by cyclin-dependent kinase (CDK) and mitogen-activated protein kinase (MAPK), involving collaborative multi-site phosphorylation of a single substrate. In budding yeast, the protein Ste5 controls signaling through a G1 arrest pathway. Upon cell-cycle entry, CDK inhibits Ste5 via multiple phosphorylation sites, disrupting its membrane association. Using quantitative time-lapse microscopy, we examined Ste5 membrane recruitment dynamics at different cell-cycle stages...
March 15, 2018: Molecular Cell
Ioannis Konstantinos Karabagias
The objectives of the present study were: (a) to evaluate the aroma evolution of raw lamb packaged in multi-layer coating film and stored at 4 ± 1 °C, with respect to storage time and (b) to investigate whether specific aldehyde ratios could serve as markers of lamb meat freshness and degree of oxidation. Volatile compounds were determined using headspace solid phase microextraction coupled to gas chromatography/mass spectrometry. Results showed that the most dominant volatiles were 2,2,4,6,6-pentamethyl-heptane, hexanal, 1-octen-3-ol, 1-hexanol, carbon disulfide and p -cymene...
March 16, 2018: Foods (Basel, Switzerland)
Benjamin H Goot, Jon Kaufman, Zhaoxing Pan, David W A Bourne, Francis Hickey, Mark Twite, Jeffrey Galinkin, Uwe Christians, Jeannie Zuk, Eduardo M da Cruz
OBJECTIVES: To assess if morphine pharmacokinetics are different in children with Down syndrome when compared with children without Down syndrome. DESIGN: Prospective single-center study including subjects with Down syndrome undergoing cardiac surgery (neonate to 18 yr old) matched by age and cardiac lesion with non-Down syndrome controls. Subjects were placed on a postoperative morphine infusion that was adjusted as clinically necessary, and blood was sampled to measure morphine and its metabolites concentrations...
March 15, 2018: Pediatric Critical Care Medicine
Li-Hui Mou, Qing-Yu Liu, Ting Zhang, Zi-Yu Li, Sheng-Gui He
Dinitrogen activation/fixation is one of the most important and challenging subjects in synthetic as well as theoretical chemistry. In this study, the adsorption reactions of N2 onto TaCn - ( n = 1-4) cluster anions have been investigated by means of mass spectrometry in conjunction with density functional theory calculations. Following the experimental results that only TaC4 - was observed to adsorb N2 , theoretical calculations predicted that TaC4 - reaction system (TaC4 - + N2 → TaC4 N2 - ) has a negligible barrier on the approach of N2 molecule while insurmountable barriers are located on the reaction pathways of TaC1-3 - /N2 reaction systems...
March 16, 2018: Journal of Physical Chemistry. A
Hiroshi Umemura, Osamu Yamasaki, Keiji Iwatsuki
No abstract text is available yet for this article.
March 16, 2018: European Journal of Dermatology: EJD
Estefanija Bogdanova, Irina Rozentale, Iveta Pugajeva, Emeka E Emecheta, Vadims Bartkevics
This work reports data on the occurrence of nine mycotoxins and two food processing contaminants - acrylamide and furan - in a total of 100 beers produced in Latvia. Mycotoxins were detected by high-performance liquid chromatography (HPLC) coupled with time-of-flight mass spectrometry, acrylamide by HPLC coupled with quadrupole-Orbitrap mass spectrometry, and furan by headspace gas chromatography-mass spectrometry. The most frequently occurring mycotoxins were HT-2 and deoxynivalenol (DON), which were detected in 52% and 51% of the analysed samples...
March 16, 2018: Food Additives & Contaminants. Part B, Surveillance
Rob Smith
Mass spectrometry is an important tool used by many scientists throughout the world. Nonetheless, feedback on the strengths and limitations of current software is often restricted to anecdote rather than formal inquiry. Over the course of 100 interviews over the state of mass spectrometry software, surprising patterns coalesced on several topics: perception of the frontier, perception of software quality, and differences between commercial and non-profit environments. Most notably, interviews suggested a substantial schism between user satisfaction with current software and developer perceptions of software quality...
March 16, 2018: Journal of Proteome Research
Alicia Algeciras-Schimnich
The post-operative management of patients with differentiated thyroid carcinoma (DTC) relies on serial measurements of serum thyroglobulin. Current methodologies for thyroglobulin quantitation vary in their analytical and clinical performance. For years, thyroglobulin radioimmunoassays (RIA) and immunometric assays (IMA) have been used despite analytical interferences from anti-thyroglobulin autoantibodies (TgAb) as well as heterophile antibodies (HAb). TgAb interference limits Tg utility as a tumor marker in ∼30% of TgAb-positive patients...
March 16, 2018: Critical Reviews in Clinical Laboratory Sciences
Aonnicha Sombatsri, Yutthapong Thummanant, Thurdpong Sribuhom, Jaursup Boonmak, Sujittra Youngme, Suphanthip Phusrisom, Veerapol Kukongviriyapan, Chavi Yenjai
Three new limonoids, limonophyllines A-C (1, 4 and 5), along with two known limonoids (2 and 3) and 11 acridone alkaloids (6-16) were isolated from the stems of Atalantia monophylla. All isolates were evaluated against cholangiocarcinoma, KKU-M156, and HepG2 cancer cell lines. Compounds 12, 14 and 16 displayed cytotoxicity against KKU-M156 cell line with IC50 ranging from 3.39 to 4.1 μg/mL while cytotoxicity against HepG2 cell line with IC50 ranging from 1.43 to 8.4 μg/mL. The structures of all isolated compounds were established by spectroscopic methods including 1D and 2D NMR, IR and mass spectrometry...
March 15, 2018: Archives of Pharmacal Research
S T Ayrton, X Chen, R M Bain, C J Pulliam, M Achmatowicz, T G Flick, D Ren, R G Cooks
Proof of concept evidence is presented for a new method for the determination of isoaspartate, an important post-translational modification. Chemical derivatization is performed using common reagents for the modification of carboxylic acids and shown to yield suitable diagnostic information with regard to isomerization at the aspartate residue. The diagnostic gas phase chemistry is probed by collision-induced dissociation mass spectrometry, on the timescale of the MS experiment and semi-quantitative calibration of the percentage of isoaspartate in a peptide sample is demonstrated...
March 15, 2018: Journal of the American Society for Mass Spectrometry
Michael Mendler, Stefan Kopf, Jan B Groener, Christin Riedinger, Thomas H Fleming, Peter P Nawroth, Jürgen G Okun
AIMS: 5-Aminoimidazole-4-carboxamide riboside (AICAR) is an endogenous activator of AMPK, a central regulator of energy homeostasis. Loss and/or reduction of AMPK signaling plays an important role in the development of insulin resistance in type 2 diabetes. The loss of AMPK in diabetes could be due to a loss of AICAR. The aim of this study was to characterize urine levels of AICAR in diabetes and determine whether an association exists with respect to late complications, e.g., retinopathy, nephropathy and neuropathy...
March 15, 2018: Acta Diabetologica
David Bonnel, Raphaël Legouffe, André H Eriksson, Rasmus W Mortensen, Fabien Pamelard, Jonathan Stauber, Kim T Nielsen
Generation of skin distribution profiles and reliable determination of drug molecule concentration in the target region are crucial during the development process of topical products for treatment of skin diseases like psoriasis and atopic dermatitis. Imaging techniques like mass spectrometric imaging (MSI) offer sufficient spatial resolution to generate meaningful distribution profiles of a drug molecule across a skin section. In this study, we use matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to generate quantitative skin distribution profiles based on tissue extinction coefficient (TEC) determinations of four different molecules in cross sections of human skin explants after topical administration...
March 15, 2018: Analytical and Bioanalytical Chemistry
H Zhao, J Wang, D Fang, O Lee, R T Chatterton, V Stearns, S A Khan, S E Bulun
Obesity is associated with increased risk of breast cancer in postmenopausal but not in premenopausal women. Many factors may be responsible for this difference. The aim of this study was to determine the mechanisms by which the genes related to the AMPK pathway, inflammation, and estrogen actions are affected by adiposity in breast tissue with the objective of identifying differences that may explain the different breast cancer risk in premenopausal and postmenopausal women. Random fine needle aspirates (rFNAs) of breast tissue were collected from 57 premenopausal and 55 postmenopausal women and were classified as normal weight, overweight, or obese...
March 15, 2018: Hormones & Cancer
Qiong Wu, Huan Zhang, Jia-Rong Ding, Zhan-Ying Hong, Hao Wu, Zhen-Yu Zhu, Zhi-Yong Guo, Yi-Feng Chai
As one of the most troublesome complications in patients with chronic renal disease, the etiology of uremic pruritus remains unknown, and the current therapeutic approaches are limited and unsatisfactory. To identify potential biomarkers for improving diagnosis and treatment and obtain a better understanding of the pathogenesis of uremic pruritus, we compared serum metabolome profiles of severe uremic pruritus (HUP) patients with mild uremic pruritus (LUP) patients using ultraperformance liquid chromatography-quadruple time-of-flight mass spectrometry (UPLC-QTOF MS)...
2018: BioMed Research International
Katie M O'Brien, Dale P Sandler, Min Shi, Quaker E Harmon, Jack A Taylor, Clarice R Weinberg
Genetic factors likely influence individuals' concentrations of 25-hydroxyvitamin D [25(OH)D], a biomarker of vitamin D exposure previously linked to reduced risk of several chronic diseases. We conducted a genome-wide association study of serum 25(OH)D (assessed using liquid chromatography-tandem mass spectrometry) and 386,449 single nucleotide polymorphisms (SNPs). Our sample consisted of 1,829 participants randomly selected from the Sister Study, a cohort of women who had a sister with breast cancer but had never had breast cancer themselves...
2018: Frontiers in Genetics
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