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Liquid Chromatography tandem mass spectrometry

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https://www.readbyqxmd.com/read/28454429/polyphenolic-compounds-from-korean-lonicera-japonica-thunb-induces-apoptosis-via-akt-and-caspase-cascade-activation-in-a549-cells
#1
Kwang Il Park, Hyeonsoo Park, Arulkumar Nagappan, Gyeong Eun Hong, Silvia Yumnam, Ho Jeong Lee, Eun Hee Kim, Won Sup Lee, Sung Chul Shin, Jin A Kim, Sang Joon Lee, Jin Yeul Ma, Taesun Min, Jeong Doo Heo, Gon Sup Kim
Lonicera japonica Thunb. (L. japonica T.) has historically been used in Korean herbal medicine due to its anticancer and protective effects on the respiratory system. In the present study, the polyphenolic compounds in L. japonica T. were investigated using high-performance liquid chromatography coupled with tandem mass spectrometry, and its anticancer effects on A549 non-small-cell lung cancer cells were studied. Polyphenolic compounds potentially inhibit A549 cells in a dose-dependent manner. Flow cytometry and western blot analysis demonstrated that polyphenolic compounds induce apoptosis by regulating the protein expression levels of caspases, poly-(ADP-ribose) polymerase and the B-cell lymphoma-2-associated X-protein/B-cell lymphoma-extra large ratio...
April 2017: Oncology Letters
https://www.readbyqxmd.com/read/28454263/investigation-of-the-cytotoxicity-apoptosis-and-pharmacokinetics-of-raddeanin-a
#2
Guiying Gu, Huanhuan Qi, Tianyue Jiang, Bo Ma, Zheng Fang, Hong Xu, Qi Zhang
Raddeanin A, one of the triterpenoid saponins extracted from Anemone raddeana rhizome of the Ranunculaceae family, has demonstrated the ability to inhibit the growth of human hepatic and gastric cancer cells. However, the effects of Raddeanin A on human colon cancer cells have not been investigated extensively. The present study aimed to examine the antiproliferative and apoptosis-inducing effects of Raddeanin A on the HCT-116 human colon cancer cell line in vitro, and evaluate the pharmacokinetic and biodistribution properties of Raddeanin A in mice following a single oral administration...
March 2017: Oncology Letters
https://www.readbyqxmd.com/read/28453638/etg-ets-in-serum-by-uhplc-ms-ms-in-suspected-sexual-assault-cases
#3
Solfrid Hegstad, Arne Helland, Cecilie Hagemann, Olav Spigset
A method including semi-automated extraction of ethyl glucuronide (EtG) and ethyl sulfate (EtS) from serum followed by ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS) has been developed and validated. Sample preparation prior to UHPLC-MS-MS analysis consisted of protein precipitation and filtration through a phospholipid removal plate. Chromatography was achieved using an HSS T3 column and gradient elution with formic acid in water in combination with methanol. The mass spectrometer was monitored in the negative mode with multiple reaction monitoring...
April 27, 2017: Journal of Analytical Toxicology
https://www.readbyqxmd.com/read/28453518/lc-ms-ms-quantitative-analysis-reveals-the-association-between-fto-and-dna-methylation
#4
Yuting Zhu, Guangyu Zhou, Xuebin Yu, Qiang Xu, Kai Wang, Dan Xie, Qingkai Yang, Lina Wang
Fat mass and obesity-associated protein (FTO) is α-ketoglutarate-dependent dioxygenase and responsible for demethylating N6-methyladenosine (m6A) in mRNA, 3-methylthymine (m3T) in single-stranded DNA (ssDNA) and 3-methyluracil (m3U) in single-stranded RNA (ssRNA). Its other function remains unknown but thousands of mammalian DNA show 5-methyl-2'-deoxycytidine (5mdC) modification and 5mdC demethylases are required for mammalian energy homeostasis and fertility. Here, we aimed to confirm whether FTO proteins can demethylate 5mdC in DNA...
2017: PloS One
https://www.readbyqxmd.com/read/28449378/analysis-of-toldimfos-in-porcine-muscle-and-bovine-milk-using-liquid-chromatography-triple-quadrupole-mass-spectrometry
#5
Dan Zhang, Jin-A Park, A M Abd El-Aty, Seong-Kwan Kim, Sang-Hyun Cho, Weijia Zheng, Jeong-Min Choi, Jae-Han Shim, Byung-Joon Chang, Jin-Suk Kim, Ho-Chul Shin
An analytical method was developed for the detection of toldimfos sodium residues in porcine muscle and bovine milk using liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) analysis. The drug was extracted from muscle and milk using 10 mM ammonium formate in acetonitrile and then purified using n-hexane. The drug was well separated on a Luna C18 column using a mixture of 10 mM ammonium formate in ultrapure water (A) and acetonitrile (B) as the mobile phase. Good linearity was achieved over the tested concentration range (0...
April 27, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28449301/the-profile-and-dynamics-of-rna-modifications-in-animals
#6
Pieter van Delft, Alper Akay, Sabrina M Huber, Christoph Bueschl, Konrad L M Rudolph, Tomás Di Domenico, Rainer Schuhmacher, Eric A Miska, Shankar Balasubramanian
More than a hundred distinct modified nucleosides have been identified in RNA, but little is known about their distribution across different organisms, their dynamic nature and their response to cellular and environmental stress. Mass-spectrometry-based methods have been at the forefront of identifying and quantifying modified nucleosides. However, they often require synthetic reference standards, which do not exist in the case of many modified nucleosides, and this therefore impedes their analysis. Here we use a metabolic labelling approach to achieve rapid generation of bio-isotopologues of the complete Caenorhabditis elegans transcriptome and its modifications and use them as reference standards to characterise the RNA modification profile in this multicellular organism through an untargeted liquid-chromatography tandem high-resolution mass spectrometry (LC-HRMS) approach...
March 16, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28449070/in-situ-screening-for-postsynaptic-cell-adhesion-molecules-during-synapse-formation
#7
Takeshi Uemura, Tomoko Shiroshima, Asami Maeda, Misato Yasumura, Takashi Shimada, Yuko Fukata, Masaki Fukata, Tomoyuki Yoshida
Neuronal synapse formation is regulated by pre- and postsynaptic cell adhesion molecules. Presynaptic neurexins (NRXNs) and receptor protein tyrosine phosphatases (RPTPs; PTPδ, PTPσ, and LAR in mammals) can induce postsynaptic differentiation through the interaction with various postsynaptic cell adhesion molecules. Here, we developed a novel in situ screening method to identify postsynaptic membranous proteins involved in synaptogenesis. Magnetic beads coated with the extracellular domains of NRXN1β(-S4) and PTPδ-A6 variants preferentially induced excitatory postsynaptic differentiation on the beads' surface when co-cultured with cortical neurons...
April 25, 2017: Journal of Biochemistry
https://www.readbyqxmd.com/read/28449051/viral-kinetics-in-semen-with-different-antiretroviral-families-in-treatment-na%C3%A3-ve-hiv-infected-patients-a-randomized-trial
#8
Alicia Gutierrez-Valencia, Omar J Benmarzouk-Hidalgo, Inmaculada Rivas-Jeremías, Nuria Espinosa, María Trujillo-Rodríguez, Tamara Fernandez-Magdaleno, Pompeyo Viciana, Luis F López-Cortés
Background: There are several regimens for starting antiretroviral treatment, but it remains unknown whether either of them is more advantageous regarding the time course and magnitude of HIV-RNA decay in semen. Objective: To evaluate the differential effect of different antiretroviral drug families on viral kinetics in seminal plasma of treatment-naïve HIV-infected patients. Methods: Phase II, randomized, open-label study in which participants were randomized 1:1:1 to receive tenofovir-DF plus emtricitabine, and either cobicistat-boosted elvitegravir (EVGcobi), rilpivirine (RPV), or ritonavir-boosted darunavir (DRVrtv)...
April 25, 2017: Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America
https://www.readbyqxmd.com/read/28448054/lipid-droplet-isolation-for-quantitative-mass-spectrometry-analysis
#9
Kathrin Rösch, Marcel Kwiatkowski, Hartmut Schlüter, Eva Herker
Lipid droplets are vital to the replication of a variety of different pathogens, most prominently the Hepatitis C Virus (HCV), as the putative site of virion morphogenesis. Quantitative lipid droplet proteome analysis can be used to identify proteins that localize to or are displaced from lipid droplets under conditions such as virus infections. Here, we describe a protocol that has been successfully used to characterize the changes in the lipid droplet proteome following infection with HCV. We use Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC) and thus label the complete proteome of one population of cells with "heavy" amino acids to quantitate the proteins by mass spectrometry...
April 17, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28448019/a-tandem-liquid-chromatography-mass-spectrometry-based-approach-for-metabolite-analysis-of-staphylococcus-aureus
#10
David J Samuels, Zhe Wang, Kyu Y Rhee, Shaun R Brinsmade
In an effort to thwart bacterial pathogens, hosts often limit the availability of nutrients at the site of infection. This limitation can alter the abundances of key metabolites to which regulatory factors respond, adjusting cellular metabolism. In recent years, a number of proteins and RNA have emerged as important regulators of virulence gene expression. For example, the CodY protein responds to levels of branched-chain amino acids and GTP and is widely conserved in low G+C Gram-positive bacteria. As a global regulator in Staphylococcus aureus, CodY controls the expression of dozens of virulence and metabolic genes...
March 28, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28446017/dexmedetomidine-oral-mucosa-patch-for-sedation-suppresses-apoptosis-in-hippocampus-of-normal-rats
#11
Je Hoon Park, Il Gyu Ko, Sung Eun Kim, Jun Jang Jin, Lakkyong Hwang, Chang Ju Kim, Soo Hwan Yoon, Jongki Hong, Jun Young Chung, Deok Won Lee
PURPOSE: Dexmedetomidine, an α2-adrenergic agonist, provides sedative and analgesic effects without significant respiratory depression. Dexmedetomidine has been suggested to have an antiapoptotic effect in response to various brain insults. We developed an oral mucosa patch using dexmedetomidine for sedation. The effects of the dexmedetomidine oral mucosa patch on cell proliferation and apoptosis in the hippocampus were evaluated. METHODS: A hydrogel oral mucosa patch was adhered onto the oral cavity of physiologically normal rats, and was attached for 2 hours, 6 hours, 12 hours, or 24 hours...
April 2017: International Neurourology Journal
https://www.readbyqxmd.com/read/28445851/development-and-validation-of-a-uhplc-esi-ms-ms-method-for-the-simultaneous-quantification-of-mammal-lysophosphatidylcholines-and-lysophosphatidylethanolamines-in-serum
#12
Susana Suárez-García, Lluís Arola, Aïda Pascual-Serrano, Anna Arola-Arnal, Gerard Aragonès, Cinta Bladé, Manuel Suárez
Recent investigations based on non-targeted metabolomics have proposed lysophospholipids (Lyso-PLs) as biomarkers of different diseases. In particular, lysophosphatidylcholines (Lyso-PCs) and lysophosphatidylethanolamines (Lyso-PEs) have been associated with serious lipid pathologies. Methods to determine the different molecular species in a biological sample and to quantify even less abundant species are required for the evaluation of the Lyso-PL pattern as a novel comprehensive biomarker of dyslipidemia. This study describes the development and validation of an ultra-high-performance liquid chromatography coupled to tandem mass spectrometry assay for the determination of a large number of Lyso-PCs and Lyso-PEs in biological samples...
April 18, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28445850/simultaneous-quantification-of-busulfan-clofarabine-and-f-ara-a-using-isotope-labelled-standards-and-standard-addition-in-plasma-by-lc-ms-ms-for-exposure-monitoring-in-hematopoietic-cell-transplantation-conditioning
#13
Arjen M Punt, Jurgen B Langenhorst, Annelies C Egas, Jaap Jan Boelens, Charlotte van Kesteren, Erik M van Maarseveen
In allogeneic hematopoietic cell transplantation (HCT) it has been shown that over- or underexposure to conditioning agents have an impact on patient outcomes. Conditioning regimens combining busulfan (Bu) and fludarabine (Flu) with or without clofarabine (Clo) are gaining interest worldwide in HCT. To evaluate and possibly adjust full conditioning exposure a simultaneous analysis of Bu, F-ARA-A (active metabolite of Flu) and Clo in one analytical run would be of great interest. However, this is a chromatographical challenge due to the large structural differences of Bu compared to F-ARA-A and Clo...
April 15, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28445849/a-reference-measurement-procedure-for-amino-acids-in-blood-using-isotope-dilution-ultra-performance-liquid-chromatography-tandem-mass-spectrometry
#14
Juok Kim, Tran Thi Thanh Huong, Seon-Pyo Hong, Ji-Seon Jeong
We described a reference measurement procedure for amino acid (AA) quantification in blood samples based on deproteinization with 5-sulfosalicylic acid (SSA) and an isotope dilution-ultra performance liquid chromatography-tandem mass spectrometry (LC-MS) method. The serum was deproteinized with 15% v/v SSA and the supernatant was injected directly into the LC-MS system without further processing. Compared with the use of other precipitants and water as a control, five model AAs-valine, isoleucine, leucine, tyrosine, and phenylalanine-in the SSA-treated samples showed ionization enhancement as well as stable background signals without significant ion suppression effects...
April 17, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28445846/a-sharp-robust-and-quantitative-method-by-liquid-chromatography-tandem-mass-spectrometry-for-the-measurement-of-ead-for-acute-radiation-syndrome-and-its-application
#15
Yiwei Zhang, Jian Li, Zhiyun Meng, Xiaoxia Zhu, Hui Gan, Ruolan Gu, Zhuona Wu, Ying Zheng, Jinbin Wei, Guifang Dou
17-Ethinyl-3,17-dihydroxyandrost-5-ene (EAD) is an agent designed for the treatment of acute radiation syndrome (ARS). Given its vital role played in the prevention and mitigation of ARS, the development of a sharp, sensitive and robust liquid chromatography tandem mass spectrometry (LC-MS/MS) method to monitor the metabolism of EAD in vivo was crucial. A new method was constructed and validated for the determination of EAD with the internal standard of androst-5-ene-3β,17β-diol (5-AED). The blood samples were precipitated with methanol, centrifuged, from which the supernatant was separated on UPLC with C18 column and eluted in gradient with acetonitrile and Milli-Q water both containing 0...
April 15, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28445814/comprehensive-profiling-and-characterization-of-coumarins-from-roots-stems-leaves-branches-and-seeds-of-chimonanthus-nitensoliv-using-ultra-performance-liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry-combined-with-modified-mass-defect-filter
#16
Ting Tan, Yun Luo, Chen-Cong Zhong, Xu Xu, Yulin Feng
Chimonanthus nitensOliv. (CNO), having been studied and developed as the tea beverages, tea raw materials and preparations, an unique species in China, have been extensively used for treating colds and influenza for centuries. In the present study, a method based on the modified mass defect filter (MDF) was firstly developed and validated for comprehensive profiling of coumarins in the different parts of CNO via ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS)...
April 17, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28445763/myosin-rod-hypophosphorylation-and-cb-kinetics-in-papillary-muscles-from-a-tnc-a8v-ki-mouse-model
#17
Masataka Kawai, Jamie R Johnston, Tarek Karam, Li Wang, Rakesh K Singh, Jose R Pinto
The cardiac troponin C (TnC)-A8V mutation is associated with hypertrophic and restrictive cardiomyopathy (HCM and RCM) in human and mice. The residue affected lies in the N-helix, a region known to affect Ca(2+)-binding affinity to the N-terminal domain. Here we report on the functional effects of this mutation in skinned papillary muscle fibers from homozygous knock-in TnC-A8V mice. Muscle fibers from left ventricle were activated at 25°C under the ionic conditions of working cardiomyocytes. The pCa-tension relationship showed a 3× increase in Ca(2+)-sensitivity and a decrease (0...
April 25, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28444931/study-of-structure-dependent-chromatographic-behavior-of-glycopeptides-using-reversed-phase-nanolc
#18
Petr Kozlik, Radoslav Goldman, Miloslav Sanda
Analysis of glycosylation is challenging due to micro- and macro-heterogeneity of the protein attachment. A combination of liquid chromatography with tandem mass spectrometry is one of the most powerful tools for glycopeptide analysis. In this work, we show the effect of various monosaccharide units on the retention time of glycopeptides. Retention behavior of several glycoforms of six peptides obtained from tryptic digest of haptoglobin, hemopexin and sex hormone binding globulin was studied on a reversed phase chromatographic column...
April 26, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28444867/urine-assay-for-tenofovir-to-monitor-adherence-in-real-time-to-tenofovir-disoproxil-fumarate-emtricitabine-as-pre-exposure-prophylaxis
#19
H C Koenig, K Mounzer, G W Daughtridge, C E Sloan, L Lalley-Chareczko, G S Moorthy, S C Conyngham, A F Zuppa, L J Montaner, P Tebas
OBJECTIVES: Tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) is approved for pre-exposure prophylaxis (PrEP) against HIV infection. Adherence is critical for the success of PrEP, but current adherence measurements are inadequate for real-time adherence monitoring. We developed and validated a urine assay to measure tenofovir (TFV) to objectively monitor adherence to PrEP. METHODS: We developed a urine assay using high-performance liquid chromatography coupled to tandem mass spectrometry with high sensitivity/specificity for TFV that allowed us to determine TFV concentrations in log10 categories between 0 and 10 000 ng/mL...
April 26, 2017: HIV Medicine
https://www.readbyqxmd.com/read/28444620/environmental-pollution-with-antimicrobial-agents-from-bulk-drug-manufacturing-industries-in-hyderabad-south-india-is-associated-with-dissemination-of-extended-spectrum-beta-lactamase-and-carbapenemase-producing-pathogens
#20
Christoph Lübbert, Christian Baars, Anil Dayakar, Norman Lippmann, Arne C Rodloff, Martina Kinzig, Fritz Sörgel
PURPOSE: High antibiotic and antifungal concentrations in wastewater from anti-infective drug production may exert selection pressure for multidrug-resistant (MDR) pathogens. We investigated the environmental presence of active pharmaceutical ingredients and their association with MDR Gram-negative bacteria in Hyderabad, South India, a major production area for the global bulk drug market. METHODS: From Nov 19 to 28, 2016, water samples were collected from the direct environment of bulk drug manufacturing facilities, the vicinity of two sewage treatment plants, the Musi River, and habitats in Hyderabad and nearby villages...
April 26, 2017: Infection
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