Sample records for ms study suggests

  1. Changes of Metabolomic Profile in Helianthus annuus under Exposure to Chromium(VI) Studied by capHPLC-ESI-QTOF-MS and MS/MS

    PubMed Central

    Gonzalez Ibarra, Alan Alexander; Wrobel, Kazimierz; Yanez Barrientos, Eunice; Corrales Escobosa, Alma Rosa; Gutierrez Corona, J. Felix; Enciso Donis, Israel

    2017-01-01

    The application of capHPLC-ESI-QTOF-MS and MS/MS to study the impact of Cr(VI) on metabolites profile in Helianthus annuus is reported. Germinated seeds were grown hydroponically in the presence of Cr(VI) (25 mgCr/L) and root extracts of the exposed and control plants were analyzed by untargeted metabolomic approach. The main goal was to detect which metabolite groups were mostly affected by Cr(VI) stress; two data analysis tools (ProfileAnalysis, Bruker, and online XCMS) were used under criteria of intensity threshold 5 · 104 cps, fold change ≥ 5, and p ≤ 0.01, yielding precursor ions. Molecular formulas were assigned based on data processing with two computational tools (SIRIUS and MS-Finder); annotation of candidate structures was performed by database search using CSI:FingerID and MS-Finder. Even though ultimate identification has not been achieved, it was demonstrated that secondary metabolism became activated under Cr(VI) stress. Among 42 candidate compounds returned from database search for seven molecular formulas, ten structures corresponded to isocoumarin derivatives and eleven were sesquiterpenes or sesquiterpene lactones; three benzofurans and four glycoside or pyrane derivatives of phenolic compounds were also suggested. To gain further insight on the effect of Cr(VI) in sunflower, isocoumarins and sesquiterpenes were selected as the target compounds for future study. PMID:29359067

  2. Histone Deacetylase Inhibitor MS-275 Exhibits Poor Brain Penetration: Pharmacokinetic Studies of [11C]MS-275 using Positron Emission Tomography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hooker, J.M.; Hooker, J.M.; Kim, S.W.

    2009-10-01

    MS-275 (entinostat) is a histone deacetylase (HDAC) inhibitor currently in clinical trials for the treatment of several types of cancer. Recent reports have noted that MS-275 can cross the blood-brain barrier (BBB) and cause region-specific changes in rodent brain histone acetylation. To characterize the pharmacokinetics and distribution of MS-275 in the brain using positron emission tomography (PET), we labeled the carbamate carbon of MS-275 with carbon-11. Using PET, we determined that [{sup 11}C]MS-275 has low uptake in brain tissue when administered intravenously to nonhuman primates. In rodent studies, we observed that pharmacokinetics and brain accumulation of [{sup 11}C]MS-275 were notmore » changed by the coadministration of large doses of unlabeled MS-275. These results, which both highlight the poor brain penetration of MS-275, clearly suggest its limitation as a therapeutic agent for the central nervous system (CNS). Moreover, our study demonstrates the effectiveness of PET at providing brain pharmacokinetic data for HDAC inhibitors. These data are important not only for the development of new compounds for peripheral cancer treatment (where CNS exclusion is often advantageous) but also for the treatment of neurological disorders (where CNS penetration is critical).« less

  3. Sensitivity of GC-EI/MS, GC-EI/MS/MS, LC-ESI/MS/MS, LC-Ag(+) CIS/MS/MS, and GC-ESI/MS/MS for analysis of anabolic steroids in doping control.

    PubMed

    Cha, Eunju; Kim, Sohee; Kim, Ho Jun; Lee, Kang Mi; Kim, Ki Hun; Kwon, Oh-Seung; Lee, Jaeick

    2015-01-01

    This study compared the sensitivity of various separation and ionization methods, including gas chromatography with an electron ionization source (GC-EI), liquid chromatography with an electrospray ionization source (LC-ESI), and liquid chromatography with a silver ion coordination ion spray source (LC-Ag(+) CIS), coupled to a mass spectrometer (MS) for steroid analysis. Chromatographic conditions, mass spectrometric transitions, and ion source parameters were optimized. The majority of steroids in GC-EI/MS/MS and LC-Ag(+) CIS/MS/MS analysis showed higher sensitivities than those obtained with other analytical methods. The limits of detection (LODs) of 65 steroids by GC-EI/MS/MS, 68 steroids by LC-Ag(+) CIS/MS/MS, 56 steroids by GC-EI/MS, 54 steroids by LC-ESI/MS/MS, and 27 steroids by GC-ESI/MS/MS were below cut-off value of 2.0 ng/mL. LODs of steroids that formed protonated ions in LC-ESI/MS/MS analysis were all lower than the cut-off value. Several steroids such as unconjugated C3-hydroxyl with C17-hydroxyl structure showed higher sensitivities in GC-EI/MS/MS analysis relative to those obtained using the LC-based methods. The steroids containing 4, 9, 11-triene structures showed relatively poor sensitivities in GC-EI/MS and GC-ESI/MS/MS analysis. The results of this study provide information that may be useful for selecting suitable analytical methods for confirmatory analysis of steroids. Copyright © 2015 John Wiley & Sons, Ltd.

  4. UPLC-QTOF-MS/MS-guided isolation and purification of sulfur-containing derivatives from sulfur-fumigated edible herbs, a case study on ginseng.

    PubMed

    Zhang, Li; Shen, Hong; Xu, Jun; Xu, Jin-Di; Li, Zhen-Ling; Wu, Jie; Zou, Ye-Ting; Liu, Li-Fang; Li, Song-Lin

    2018-04-25

    In this study, a novel ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS/MS)-guidance strategy was proposed for preparation of sulfur-containing derivatives in sulfur-fumigated edible herbs. Being versatile in both chromatographic separation and mass spectrometric detection, UPLC-QTOF-MS/MS was inducted into each experimental step for multifaceted purposes including finding, tracking, purity determination and structural elucidation of targeted compounds as well as UPLC-HPLC chromatographic conditions transplantation, whereby the isolation and purification procedures were greatly facilitated. Using this strategy, a new sulfur-containing ginsenoside Rg 1 derivative (named compound I) was obtained from sulfur-fumigated ginseng. The chemical structure of compound I was elucidated to be (3β, 6α, 12β)-3, 12-dihydroxydammar-25-ene-6, 20-diylbis-β-d-glucopyranoside, 24-sulfonic acid by QTOF-MS/MS, 1 H-NMR and 13 C-NMR analysis, and its generation mechanisms by sulfur-fumigation were accordingly discussed. The research deliverable suggests that the UPLC-QTOF-MS/MS-guidance strategy is promising for targeted preparation of sulfur-containing derivatives from sulfur-fumigated edible herbs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Methods for the analysis of organophosphorus flame retardants-Comparison of GC-EI-MS, GC-NCI-MS, LC-ESI-MS/MS, and LC-APCI-MS/MS.

    PubMed

    Tokumura, Masahiro; Miyake, Yuichi; Wang, Qi; Nakayama, Hayato; Amagai, Takashi; Ogo, Sayaka; Kume, Kazunari; Kobayashi, Takeshi; Takasu, Shinji; Ogawa, Kumiko

    2018-04-16

    Organophosphorus flame retardants (PFRs) are extensively used as alternatives to banned polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). In this study, we analyzed 14 PFRs by means of four mass-spectrometry-based methods: gas chromatography combined with electron-impact mass spectrometry (GC-EI-MS) or negative-chemical-ionization mass spectrometry (GC-NCI-MS) and liquid chromatography combined with tandem mass spectrometry using electrospray ionization (LC-ESI-MS/MS) or atmospheric pressure chemical ionization (LC-APCI-MS/MS). The limits of quantification (LOQs) for LC-ESI-MS/MS and LC-APCI-MS/MS (0.81-970 pg) were 1-2 orders of magnitude lower than the LOQs for GC-EI-MS and GC-NCI-MS (2.3-3900 pg). LC-APCI-MS/MS showed the lowest LOQs (mean = 41 pg; median = 3.4 pg) for all but two of the PFRs targeted in this study. For LC-APCI-MS/MS, the lowest LOQ was observed for tributyl phosphate (TBP) (0.81 pg), and the highest was observed for tris(butoxyethyl) phosphate (TBOEP) (36 pg). The results of this study indicate that LC-APCI-MS/MS is the optimum analytical method for the target PFRs, at least in terms of LOQ.

  6. High Throughput Analytical Techniques for the Determination and Confirmation of Residues of 653 Multiclass Pesticides and Chemical Pollutants in Tea by GC/MS, GC/MS/MS, and LC/MS/MS: Collaborative Study, First Action 2014.09.

    PubMed

    Pang, Guo-Fang; Fan, Chun-Lin; Cao, Yan-Zhong; Yan, Fang; Li, Yan; Kang, Jian; Chen, Hui; Chang, Qiao-Ying

    2015-01-01

    Thirty laboratories from fom North and South America, Europe, and Asia participated in this AOAC collaborative study (15 from China; five from Germany; two each from Italy and the United States; and one each from the Republic of Korea, Canada, Spain, Japan, Belgium, and India). Participants represented government regulatory, commercial testing, university, research institute, and private laboratories. The single-laboratory validated (SLV) tea method was evaluated in the collaborative study to determine the recovery and reproducibility of the method under multilaboratory conditions. Since there were no restrictions regarding the type of analytical instrumentation to use for the analyses, laboratories used a combination of equipment that included GC/MS, GC/MS/MS, and LC/MS/MS instruments from 22 different manufacturers, 21 brands of GC and LC columns, 13 different GC temperature programming profiles, 11 LC gradient elution programs, and six different vendor manufactured SPE cartridges. Even though all the analytical performance parameters for all the 653 compounds had been determined in the SLV study, guidance was obtained from an expert review panel of the AOAC Method-Centric Committee on Pesticide Residues to conduct the multilaboratory collaborative study based on 20 selected compounds that can be analyzed by GC/MS and 20 compounds that can be analyzed by LC/MS/MS. Altogether, 560 samples covering the 40 selected pesticides were analyzed in the study. These samples included green tea and oolong tea samples fortified typically at the European Union maximum residue limit for regulatory guidance and compliance, aged tea samples incurred with 20 pesticides, and green tea and oolong tea samples incurred with five pesticides. The analysis of the 560 samples generated a total of 82 459 test results by the 30 participating laboratories. One laboratory failed to meet the proficiency requirements in the precollaborative study. Therefore, its data submitted for the

  7. Anti-myelin antibodies predict the clinical outcome after a first episode suggestive of MS.

    PubMed

    Tomassini, V; De Giglio, L; Reindl, M; Russo, P; Pestalozza, I; Pantano, P; Berger, T; Pozzilli, C

    2007-11-01

    The aim of this study was to test the contribution of anti-myelin antibodies in predicting conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS) when considering either Poser's or McDonald's diagnostic criteria. Fifty-one patients with CIS and abnormal brain MRI were imaged monthly for six months and then at 12, 18, 24, 36 months. At baseline serum samples testing antibodies against myelin oligodendrocyte glycoprotein (anti-MOG) and myelin basic protein (anti-MBP) were collected. During the 36-month follow-up, 26 (51%) patients developed a relapse thus becoming clinically definite MS (CDMS) according to Poser's criteria; 46 (90.2%) patients converted to MS according to McDonald's criteria. Out of 51 patients, 28 (54.9%) had either double or single positivity for anti-myelin antibodies. Antibody status significantly predicted MS according to Poser's criteria (P=0.004), but did not according to the McDonald's criteria. When compared to antibody negative patients, the risk of developing a relapse was 8.9 (95% CI: 2.7-29.8; P<0.001) for anti-MBP positive (anti-MBP+) patients and 1.5 (95% CI: 0.4-5.4; P=0.564) for those anti-MOG positive (anti-MOG+); double positive patients (ie, anti-MBP+/anti-MOG+) had a risk of relapse's occurrence equal to 3.4 (95% CI: 1.1-10.2; P=0.031). Also, the antibody status predicted the median time span from CIS to CDMS, that was of 36 months in the anti-MOG-/anti-MBP- group, 33 months in the anti-MOG+/anti-MBP- group, 24 months in the anti-MOG+/anti-MBP+ group and 12 months in the anti-MOG-/anti-MBP+ patients (P=0.003 by ANOVA). Our data support the prognostic value of anti-myelin antibodies in CIS patients at risk of CDMS, with positive patients showing shorter time interval to relapse occurrence than negative patients.

  8. Metabolomic and elemental analysis of camel and bovine urine by GC-MS and ICP-MS.

    PubMed

    Ahamad, Syed Rizwan; Alhaider, Abdul Qader; Raish, Mohammad; Shakeel, Faiyaz

    2017-01-01

    Recent studies from the author's laboratory indicated that camel urine possesses antiplatelet activity and anti-cancer activity which is not present in bovine urine. The objective of this study is to compare the volatile and elemental components of bovine and camel urine using GC-MS and ICP-MS analysis. We are interested to know the component that performs these biological activities. The freeze dried urine was dissolved in dichloromethane and then derivatization process followed by using BSTFA for GC-MS analysis. Thirty different compounds were analyzed by the derivatization process in full scan mode. For ICP-MS analysis twenty eight important elements were analyzed in both bovine and camel urine. The results of GC-MS and ICP-MS analysis showed marked difference in the urinary metabolites. GC-MS evaluation of camel urine finds a lot of products of metabolism like benzene propanoic acid derivatives, fatty acid derivatives, amino acid derivatives, sugars, prostaglandins and canavanine. Several research reports reveal the metabolomics studies on camel urine but none of them completely reported the pharmacology related metabolomics. The present data of GC-MS suggest and support the previous studies and activities related to camel urine.

  9. Positive and negative ion mode ESI-MS and MS/MS for studying drug-DNA complexes

    NASA Astrophysics Data System (ADS)

    Rosu, Frédéric; Pirotte, Sophie; Pauw, Edwin De; Gabelica, Valérie

    2006-07-01

    We report systematic investigation of duplex DNA complexes with minor groove binders (Hoechsts 33258 and 33342, netropsin and DAPI) and intercalators (daunomycin, doxorubicin, actinomycin D, ethidium, cryptolepine, neocryptolepine, m-Amsacrine, proflavine, ellipticine and mitoxantrone) by ESI-MS and ESI-MS/MS in the negative ion mode and in the positive ion mode. The apparent solution phase equilibrium binding constants can be determined by measuring relative intensities in the ESI-MS spectrum. While negative ion mode gives reliable results, positive ion mode gives a systematic underestimation of the binding constants and even a complete suppression of the complexes for intercalators lacking functional groups capable of interacting in the grooves. In the second part of the paper we systematically compare MS/MS fragmentation channels and breakdown curves in the positive and the negative modes, and discuss the possible uses and caveats of MS/MS in drug-DNA complexes. In the negative mode, the drugs can be separated in three groups: (1) those that leave the complex with no net charge; (2) those that leave the complex with a negative charge; and (3) those that remain attached on the strands upon dissociation of the duplex due to their positive charge. In the positive ion mode, all complexes fragment via the loss of protonated drug. Information on the stabilization of the complex by drug-DNA noncovalent interactions can be obtained straightforwardly only in the case of neutral drug loss. In all other cases, proton affinity (in the positive ion mode), gas-phase basicity (in the negative ion mode) and coulombic repulsion are the major factors influencing the fragmentation channel and the dissociation kinetics.

  10. Application of the ex-Gaussian function to the effect of the word blindness suggestion on Stroop task performance suggests no word blindness

    PubMed Central

    Parris, Benjamin A.; Dienes, Zoltan; Hodgson, Timothy L.

    2013-01-01

    The aim of the present paper was to apply the ex-Gaussian function to data reported by Parris et al. (2012) given its utility in studies involving the Stroop task. Parris et al. showed an effect of the word blindness suggestion when Response-Stimulus Interval (RSI) was 500 ms but not when it was 3500 ms. Analysis revealed that: (1) The effect of the suggestion on interference is observed in μ, supporting converging evidence indicating the suggestion operates over response competition mechanisms; and, (2) Contrary to Parris et al. an effect of the suggestion was observed in μ when RSI was 3500 ms. The reanalysis of the data from Parris et al. (2012) supports the utility of ex-Gaussian analysis in revealing effects that might otherwise be thought of as absent. We suggest that word reading itself is not suppressed by the suggestion but instead that response conflict is dealt with more effectively. PMID:24065947

  11. Application of the ex-Gaussian function to the effect of the word blindness suggestion on Stroop task performance suggests no word blindness.

    PubMed

    Parris, Benjamin A; Dienes, Zoltan; Hodgson, Timothy L

    2013-01-01

    The aim of the present paper was to apply the ex-Gaussian function to data reported by Parris et al. (2012) given its utility in studies involving the Stroop task. Parris et al. showed an effect of the word blindness suggestion when Response-Stimulus Interval (RSI) was 500 ms but not when it was 3500 ms. Analysis revealed that: (1) The effect of the suggestion on interference is observed in μ, supporting converging evidence indicating the suggestion operates over response competition mechanisms; and, (2) Contrary to Parris et al. an effect of the suggestion was observed in μ when RSI was 3500 ms. The reanalysis of the data from Parris et al. (2012) supports the utility of ex-Gaussian analysis in revealing effects that might otherwise be thought of as absent. We suggest that word reading itself is not suppressed by the suggestion but instead that response conflict is dealt with more effectively.

  12. Single-cell analysis by ICP-MS/MS as a fast tool for cellular bioavailability studies of arsenite.

    PubMed

    Meyer, S; López-Serrano, A; Mitze, H; Jakubowski, N; Schwerdtle, T

    2018-01-24

    Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) has become a powerful and fast tool to evaluate the elemental composition at a single-cell level. In this study, the cellular bioavailability of arsenite (incubation of 25 and 50 μM for 0-48 h) has been successfully assessed by SC-ICP-MS/MS for the first time directly after re-suspending the cells in water. This procedure avoids the normally arising cell membrane permeabilization caused by cell fixation methods (e.g. methanol fixation). The reliability and feasibility of this SC-ICP-MS/MS approach with a limit of detection of 0.35 fg per cell was validated by conventional bulk ICP-MS/MS analysis after cell digestion and parallel measurement of sulfur and phosphorus.

  13. Determination and pharmacokinetic study of Enasidenib in rat plasma by UPLC-MS/MS.

    PubMed

    Pang, Ni-Hong; Liu, Qian; Lu, Xiang-Ran; Yang, Su-Fen; Lin, Dong-Dong; Hu, Guo-Xin

    2018-04-27

    Enasidenib, an oral product for treating Acute Myeloid Leukemia, has been approved by FDA in Aug, 2017. In this study, we set up an ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method for measuring Enasidenib and imatinib (internal standard, IS), simultaneously. Enasidenib and imatinib were separated on an ACQUITY UPLC BEH C 18 Column (2.1 mm × 50 mm, 1.7 μm, 132 Å). Mass detection was carried out by electrospray ionization in the position mode, and the multiple reaction monitoring transitions were m/z 474.23 → 456.17 and m/z 494.30 → 394.20 for Enasidenib and imatinib, respectively. Linearity (2 - 500 ng·mL -1 , R 2  > 0.999), precision and accuracy (RE < ± 15%), extraction recovery (≥ 96.69%), matrix effect (≥ 96.47%) and stability (RE < ± 10%) were validated which demonstrated the robustness of our method. This rapid, efficient and reliable UPLC-MS/MS method shows specificity and repeatability of Enasidenib in rat plasma and can be used in further pharmacokinetic studies. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. High-Throughput Analytical Techniques for the Determination of the Residues of 653 Multiclass Pesticides and Chemical Pollutants in Tea, Part VII: A GC-MS, GC-MS/MS, and LC-MS/MS Study of the Degradation Profiles of Pesticide Residues in Green Tea.

    PubMed

    Chang, Qiao-Ying; Pang, Guo-Fang; Fan, Chun-Lin; Chen, Hui; Yang, Fang; Li, Jie; Wen, Bi-Fang

    2016-11-01

    GC-MS, GC-tandem MS (MS/MS), and LC-MS/MS were used to mathematically define the degradation profiles of pesticide residues in two field trials. Nineteen pesticides were studied in the first field trial and 11 in the second. The results of the field trials demonstrated that the degradation profiles of pesticide residues in green tea can be described with power functions to successfully estimate the amount of time, following pesticide application, pesticide residues appearing in tea in concentrations at and/or above the maximum residue limit (MRL) decrease to concentrations below the MRL. Stability tests on green tea samples stored at room temperature were conducted to determine whether pesticide-incurred green tea samples prepared according to the method used in the field trials would be suitable for the preparation of reference standards for laboratory-proficiency testing trials. This paper reports the results of a GC-MS, GC-MS/MS, and LC-MS/MS study, as well as the suitability of the samples prepared under these conditions for use as pesticide reference standards in tea analysis.

  15. Rugged LC-MS/MS survey analysis for acrylamide in foods.

    PubMed

    Roach, John A G; Andrzejewski, Denis; Gay, Martha L; Nortrup, David; Musser, Steven M

    2003-12-17

    The described liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of acrylamide in food entails aqueous room temperature extraction, SPE cleanup, and analysis by LC-MS/MS. The method is applicable to a wide variety of foods. [(13)C(3)]acrylamide is the internal standard. The limit of quantitation is 10 ppb (microg/kg). Data were obtained in duplicate from >450 products representing >35 different food types. The variability in analyte levels in certain food types suggests that it may be possible to reduce acrylamide levels in those foods.

  16. Identification and mechanism of formation of potentially genotoxic metabolites of tamoxifen: study by LC-MS/MS.

    PubMed

    Lim, C K; Yuan, Z X; Jones, R M; White, I N; Smith, L L

    1997-06-01

    On-line high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI MS) and tandem mass spectrometry (MS/MS) have been applied to the study of tamoxifen metabolism in liver microsomes and to the identification of potentially genotoxic metabolites. The results showed that the hydroxylated derivatives, including 4-hydroxytamoxifen and alpha-hydroxytamoxifen are detoxication metabolites, while arene oxides, their free radical precursors or metabolic intermediates, are the most probable species involved in DNA-adduct formation.

  17. Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods.

    PubMed

    Ono, H; Chuda, Y; Ohnishi-Kameyama, M; Yada, H; Ishizaka, M; Kobayashi, H; Yoshida, M

    2003-03-01

    Acrylamide concentrations in processed foods (63 samples covering 31 product types) from Japan were analysed by LC-MS/MS and GC-MS methods. The limit of detection and limit of quantification of acrylamide were 0.2 ng x ml(-1) (6 fmol) and 0.8 ng x ml(-1) (22 fmol), respectively, by LC-MS/MS, and those of 2,3-dibromopropionamide derived from acrylamide were 12 ng x ml(-1) (52 fmol) and 40 ng x ml(-1) (170 fmol), respectively, by GC-MS. Repeatability given as RSD was <5 and <15% for the LC-MS/MS and GC-MS methods, respectively. High correlation (r(2) - 0.946) was observed between values obtained by the two methods. Most potato crisps and whole potato-based fried snacks showed acrylamide concentrations >1000 microg x kg(-1). The concentrations in non-whole potato-based snacks, rice crackers processed by grilling or frying, and candied sweet potatoes were lower compared with those in the potato crisps and the whole potato-based fried snacks. One of the whole potato-based fried snacks, however, showed low acrylamide concentration (<50 microg x kg(-1)) suggesting the formation of acrylamide is strongly influenced by processing conditions. Acrylamide concentrations in instant precooked noodles and won-tons were <100 microg x kg(-1) with only one exception. Roasted barley grains for 'Mugi-cha' tea contained 200-600 microg x kg(-1) acrylamide.

  18. UPLC-MS/MS quantitative analysis and structural fragmentation study of five Parmotrema lichens from the Eastern Ghats.

    PubMed

    Kumar, K; Siva, Bandi; Sarma, V U M; Mohabe, Satish; Reddy, A Madhusudana; Boustie, Joel; Tiwari, Ashok K; Rao, N Rama; Babu, K Suresh

    2018-07-15

    Comparative phytochemical analysis of five lichen species [Parmotrema tinctorum (Delise ex Nyl.) Hale, P. andinum (Mull. Arg.) Hale, P. praesorediosum (Nyl.) Hale, P. grayanum (Hue) Hale, P. austrosinense (Zahlbr.) Hale] of Parmotrema genus were performed using two complementary UPLC-MS systems. The first system consists of high resolution UPLC-QToF-MS/MS spectrometer and the second system consisted of UPLC-MS/MS in Multiple Reaction Monitoring (MRM) mode for quantitative analysis of major constituents in the selected lichen species. The individual compounds (47 compounds) were identified using Q-ToF-MS/MS, via comparison of the exact molecular masses from their MS/MS spectra, the comparison of literature data and retention times to those of standard compounds which were isolated from crude extract of abundant lichen, P. tinctorum. The analysis also allowed us to identify unknown peaks/compounds, which were further characterized by their mass fragmentation studies. The quantitative MRM analysis was useful to have a better discrimination of species according to their chemical profile. Moreover, the determination of antioxidant activities (ABTS + inhibition) and Advance Glycation Endproducts (AGEs) inhibition carried out for the crude extracts revealed a potential antiglycaemic activity to be confirmed for P. austrosinense. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Evaluation of tamoxifen and metabolites by LC-MS/MS and HPLC methods.

    PubMed

    Heath, D D; Flat, S W; Wu, A H B; Pruitt, M A; Rock, C L

    2014-01-01

    Epidemiological and laboratory evidence suggests that quantification of serum or plasma levels of tamoxifen and its metabolites, 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), Z-4-hydroxytamoxifen (4HT), N-desmethyl-tamoxifen (ND-tam), is a clinically useful tool in the assessment and monitoring of breast cancer status in patients taking adjuvant tamoxifen. A liquid chromatographic mass spectrometric method (LC-MS/MS) was used to measure the blood levels of tamoxifen and its metabolites. This fully automated analytical method is specific, accurate and sensitive. The LC-MS/MS automated technique has now become a widely accepted reference method. This study analysed a randomly selected batch of blood samples from participants enrolled in a breast cancer study to compare results from this reference method in 40 samples with those obtained from a recently developed high-performance liquid chromatography (HPLC) method with fluorescence detection. The mean (SD) concentrations for the LC-MS/MS method (endoxifen 12.6 [7.5] ng/mL, tamoxifen 105 [44] ng/mL, 4-HT 1.9 [1.0] ng/mL, ND-tam 181 [69] ng/mL) and the HPLC method (endoxifen 13.1 [7.8] ng/mL, tamoxifen 108 [55] ng/mL, 4-HT 1.8 [0.8] ng/mL, ND-tam 184 [81] ng/mL) did not show any significant differences. The results confirm that the HPLC method offers an accurate and comparable alternative for the quantification of tamoxifen and tamoxifen metabolites.

  20. ESI-MS2 and Anti-inflammatory Studies of Cyclopropanic Triterpenes. UPLC-ESI-MS and MS2 Search of Related Metabolites from Donella ubanguiensis.

    PubMed

    Sandjo, Louis P; Nascimento, Marcus V P Dos Santos; da Silva, Layzon A L; Munhoz, Antonio C M; Pollo, Luiz A E; Biavatti, Maique W; Ngadjui, Bonaventure T; Opatz, Till; Fröde, Tania S

    2017-01-01

    Triterpenes are one of the largest secondary metabolites groups spread in the plant kingdom with various skeletons. These metabolites have showed various bioactivities including anti-inflammatory activity. The study aims to explore the mass spectrometry fragmentation of donellanic acids A-C (DA A-C), three compounds identified from Donella ubanguiensis; in addition, the fragmentation behaviour of these metabolites will serve as a fingerprint to search and characterise triterpenes congeners in fruits, bark and wood crude extracts of D. ubanguiensis. This work was prompted by the anti-inflammatory activity on leukocyte migration, exudate concentrations and myeloperoxidase activity obtained for DA A-B. The bioactivity was performed on mouse model of pleurisy induced by carrageenan and the parameters were analysed by veterinarian automated cell counter and colorimetric assays. While the tandem mass analyses of DA A-C were carried out by a direct infusion ESI-QTOF-MS/MS, the extracts were studied by UPLC-ESI-QTOF-MS and UPLC-ESI-QTOF-MS/MS. DA A displayed interesting anti-inflammatory activity by inhibiting leukocyte migration, exudate concentrations and myeloperoxidase activity (p < 0.05) while DA B was weakly active (p > 0.05). Moreover, the diagnostic of the MS 2 behaviour of DA A-C in conjunction with the chromatograms and the obtained MS 2 data of the crude extract led to the characterisation of three cyclopropane triterpenes (T1-T3) and six saponins (T4-T9) from the fruits, the bark, and the wood extracts. Donella species deserve more investigation since metabolites related to the anti-inflammatory compound (DA A) could be identified. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Chemical characterization of Azadirachta indica grafted on Melia azedarach and analyses of azadirachtin by HPLC-MS-MS (SRM) and meliatoxins by MALDI-MS.

    PubMed

    Forim, Moacir Rossi; Cornélio, Vivian Estevam; da Silva, M Fátima das G F; Rodrigues-Filho, Edson; Fernandes, João B; Vieira, Paulo C; Matinez, Sueli Souza; Napolitano, Michael P; Yost, Richard A

    2010-01-01

    Melia azedarach adapted to cool climates was selected as rootstocks for vegetative propagation of Azadirachta indica. Cleft grafting of A. indica on M. azedarach rootstock showed excellent survival. Little is known about the chemistry of grafting. The roots, stems, leaves and seeds of this graft were examined in order to verify if grafted A. indica would produce limonoids different from those found in non-grafted plants. Intact matured fruits were also studied to verify if they were free of meliatoxins. After successive chromatographic separations the extracts afforded several limonoids. HPLC-MS/MS and MALDI-MS were used to develop sensitive methods for detecting azadirachtin on all aerial parts of this graft and meliatoxins in fruits, respectively. The stem afforded the limonoid salannin, which was previously found in the oil seeds of A. indica. Salannin is also found in the root bark of M. azedarach. Thus, the finding of salannin in this study suggests that it could have been translocated from the M. azedarach rootstock to the A. indica graft. HPLC-MS/MS analyses showed that azadirachtin was present in all parts of the fruits, stem, flowers and root, but absent in the leaves. The results of MALDI-MS analyses confirmed the absence of meliatoxins in graft fruits. This study showed that A. indica grafted onto M. azedarach rootstock produces azadirachtin, and also that its fruits are free of meliatoxins from rootstocks, confirming that this graft forms an excellent basis for breeding vigorous Neem trees in cooler regions.

  2. Investigation of enrofloxacin residues in broiler tissues using ELISA and LC-MS/MS.

    PubMed

    Panzenhagen, Pedro Henrique N; Aguiar, Waldemir S; Gouvêa, Raquel; de Oliveira, Andréa M G; Barreto, Fabiano; Pereira, Virgínia L A; Aquino, Maria Helena C

    2016-01-01

    This study investigated the efficiency of an enrofloxacin ELISA test kit to detect the presence of enrofloxacin residues in broiler tissues compared with LC-MS/MS. Broiler tissues from 72 samples consisting of 60 breast muscle, six pools of livers (500 g each) and six pools of kidneys (500 g each) were obtained from six different slaughterhouses. Breast muscle from 10 carcasses and pools of livers and kidneys from approximately 200 carcasses of the same flock were collected from each slaughterhouse. ELISA and HPLC were used to identify and quantify the contamination of the samples with enrofloxacin. A total of 72% of the analysed samples contained enrofloxacin residues detected by the ELISA and 22.2% were detected by LC-MS/MS. The mean values of enrofloxacin contamination found in chicken breast by ELISA and HPLC were 8.63 and 12.25 μg kg(-1), respectively. None of the samples exceeded the maximum limit of 100 μg kg(-1) by both methods set by the European Union as well as the Brazilian Agriculture Ministry. All positive samples for enrofloxacin residues detected by LC-MS/MS were also positive by ELISA. These data confirm the efficiency of the ELISA test, and suggest its use as a screening method for enrofloxacin residues in poultry tissues due to its quick results, low price and ease of applicability.

  3. International Pediatric MS Study Group Clinical Trials Summit: meeting report.

    PubMed

    Chitnis, Tanuja; Tardieu, Marc; Amato, Maria Pia; Banwell, Brenda; Bar-Or, Amit; Ghezzi, Angelo; Kornberg, Andrew; Krupp, Lauren B; Pohl, Daniela; Rostasy, Kevin; Tenembaum, Silvia; Waubant, Emmanuelle; Wassmer, Evangeline

    2013-03-19

    Pediatric studies for new biological agents are mandated by recent legislation, necessitating careful thought to evaluation of emerging multiple sclerosis (MS) therapies in children with MS. Challenges include a small patient population, the lack of prior randomized clinical trials, and ethical concerns. The goal of this meeting was to assess areas of consensus regarding clinical trial design and outcome measures among academic experts involved in pediatric MS care and research. The Steering Committee of the International Pediatric MS Study Group identified key focus areas for discussion. A total of 69 meeting attendees were assembled, including 35 academic experts. Regulatory and pharmaceutical representatives also attended, and provided input, which informed academic expert consensus decisions. The academic experts agreed that clinical trials were necessary in pediatric MS to obtain pharmacokinetic, safety and efficacy data, and regulatory approval allowing for greater medication access. The academic experts agreed that relapse was an appropriate primary outcome measure for phase III pediatric trials. An international standardized cognitive battery was identified. The pros and cons of various trial designs were discussed. Guidelines surrounding MRI studies, pharmacokinetics, pharmacodynamics, and registries were developed. The academic experts agreed that given the limited subject pool, a stepwise approach to the launch of clinical trials for the most promising medications is necessary in order to ensure study completion. Alternative approaches could result in unethical exposure of patients to trial conditions without gaining knowledge. Consensus points for conduct of clinical trials in the rare disease pediatric MS were identified amongst a panel of academic experts, informed by regulatory and industry stakeholders.

  4. Potential Health Benefits and Metabolomics of Camel Milk by GC-MS and ICP-MS.

    PubMed

    Ahamad, Syed Rizwan; Raish, Mohammad; Ahmad, Ajaz; Shakeel, Faiyaz

    2017-02-01

    None of the research reports reveals the metabolomics and elemental studies on camel milk. Recent studies showed that camel milk possesses anticancer and anti-inflammatory activity. Metabolomics and elemental studies were carried out in camel milk which showed us the pathways and composition that are responsible for the key biological role of camel milk. Camel milk was dissolved in methanol and chloroform fraction and then vortexed and centrifuged. Both the fractions were derivatized by N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA) and TMCS after nitrogen purging and analyzed by GC-MS. Camel milk was also analyzed by ICP-MS after microwave digestion. We found that higher alkanes and fatty acids are present in the chloroform fraction and amino acids, sugars and fatty acid derivatives are present in aqueous fractions. All the heavy metals like As, Pb, Cd, Co, Cu, and Ni were in the safe limits in terms of maximum daily intake of these elements. Na, K, Mg, and Ca were also present in the safe limits in terms of maximum daily intake of these elements. These results suggested that the camel milk drinking is safe and there is no health hazard. The present data of GC-MS and ICP-MS correlate the activities related to camel milk.

  5. Differential Cationization of Fatty Acids with Monovalent Cations Studied by ESI-MS/MS and Computational Approach.

    PubMed

    Sudarshana Reddy, B; Pavankumar, P; Sridhar, L; Saha, Soumen; Narahari Sastry, G; Prabhakar, S

    2018-04-24

    The intercellular and intracellular transport of charged species (Na + /K + ) entail interaction of the ions with neutral organic molecules and formation of adduct ions. The rate of transport of the ions across the cell membrane(s) may depend on the stability of the adduct ions, which in turn rely on structural aspects of the organic molecules that interact with the ions. Positive ion ESI mass spectra were recorded for the solutions containing fatty acids (FAs) and monovalent cations (X=Li + , Na + , K + , Rb + and Cs + ). Product ion spectra of the [FA+X] + ions were recorded at different collision energies. Theoretical studies were exploited under both gas phase and solvent phase to investigate the structural effects of the fatty acids during cationization. Stability of [FA+X] + adduct ions were further estimated by means of AIM topological analyses and interaction energy (IE) values. Positive ion ESI-MS analyses of the solution of FAs and X + ions showed preferential binding of the K + ions to FAs. The K + ion binding increased with the increase in number of double bonds of FAs, while decreased with increase in the number of carbons of FAs. Dissociation curves of [FA+X] + ions indicated the relative stability order of the [FA+X] + ions and it was in line with the observed trends in ESI-MS. The solvent phase computational studies divulged the mode of binding and the binding efficiencies of different FAs with monovalent cations. Among the studied monovalent cations, the cationization of FAs follow the order K + >Na + >Li + >Rb + >Cs + . The docosahexaenoic acid showed high efficiency in binding with K + ion. The K + ion binding efficiency of FAs depends on the number of double bonds in unsaturated FAs and the carbon chain length in saturated FAs. The cationization trends of FAs obtained from the ESI-MS, ESI-MS/MS analyses were in good agreement with solvent phase computational studies. This article is protected by copyright. All rights reserved.

  6. Comparison of ESI- and APCI-LC-MS/MS methods: A case study of levonorgestrel in human plasma.

    PubMed

    Wang, Rulin; Zhang, Lin; Zhang, Zunjian; Tian, Yuan

    2016-12-01

    Electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) techniques for liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of levonorgestrel were evaluated. In consideration of difference in ionization mechanism, the two ionization sources were compared in terms of LC conditions, MS parameters and performance of method. The sensitivity for detection of levonorgestrel with ESI was 0.25 ng/mL which was lower than 1 ng/mL with APCI. Matrix effects were evaluated for levonorgestrel and canrenone (internal standard, IS) in human plasma, and the results showed that APCI source appeared to be slightly less liable to matrix effect than ESI source. With an overall consideration, ESI was chosen as a better ionization technique for rapid and sensitive quantification of levonorgestrel. The optimized LC-ESI-MS/MS method was validated for a linear range of 0.25-50 ng/mL with a correlation coefficient ≥0.99. The intra- and inter-batch precision and accuracy were within 11.72% and 6.58%, respectively. The application of this method was demonstrated by a bioequivalence study following a single oral administration of 1.5 mg levonorgestrel tablets in 21 Chinese healthy female volunteers.

  7. LC-MS/MS quantification of next-generation biotherapeutics: a case study for an IgE binding Nanobody in cynomolgus monkey plasma.

    PubMed

    Sandra, Koen; Mortier, Kjell; Jorge, Lucie; Perez, Luis C; Sandra, Pat; Priem, Sofie; Poelmans, Sofie; Bouche, Marie-Paule

    2014-05-01

    Nanobodies(®) are therapeutic proteins derived from the smallest functional fragments of heavy chain-only antibodies. The development and validation of an LC-MS/MS-based method for the quantification of an IgE binding Nanobody in cynomolgus monkey plasma is presented. Nanobody quantification was performed making use of a proteotypic tryptic peptide chromatographically enriched prior to LC-MS/MS analysis. The validated LLOQ at 36 ng/ml was measured with an intra- and inter-assay precision and accuracy <20%. The required sensitivity could be obtained based on the selectivity of 2D LC combined with MS/MS. No analyte specific tools for affinity purification were used. Plasma samples originating from a PK/PD study were analyzed and compared with the results obtained with a traditional ligand-binding assay. Excellent correlations between the two techniques were obtained, and similar PK parameters were estimated. A 2D LC-MS/MS method was successfully developed and validated for the quantification of a next generation biotherapeutic.

  8. Analysis of phytochemical variations in dioecious Tinospora cordifolia stems using HPLC/QTOF MS/MS and UPLC/QqQLIT -MS/MS.

    PubMed

    Bajpai, Vikas; Singh, Awantika; Chandra, Preeti; Negi, M P S; Kumar, Nikhil; Kumar, Brijesh

    2016-01-01

    The stem of dioecious Tinospora cordifolia (Menispermaceae) is a commonly used traditional Ayurvedic medicine in India having several therapeutic properties. To develop and validate LC-MS methods for the identification and simultaneous quantitation of various secondary metabolites and to study metabolomic variations in the stem of male and female plants. Ethanolic extract of stems were analysed by HPLC/ESI-QTOF-MS/MS for rapid screening of bioactive phytochemicals. High resolution MS and MS/MS in positive ESI mode were used for structural investigation of secondary metabolites. An UPLC/ESI-QqQ(LIT) -MS/MS method in MRM mode was developed and validated for the simultaneous quantitation of five bioactive alkaloids. Identification and characterisation of 36 metabolites including alkaloids, sesquiterpenes and phytoecdysteroids were performed using LC-MS and MS/MS techniques. The bioactive alkaloids such as jatrorrhizine, magnoflorine, isocorydine, palmatine and tetrahydropalmatine were successfully quantified in male and female plants. The mean abundances of magnoflorine jatrorrhizine, and oblongine were significantly (P < 0.05) higher in male plants while mean abundances of tetrahydropalmatine, norcoclaurine, and reticuline were significantly (P < 0.05) higher in female plants. Phytochemicals in the stem of male and female Tinospora cordifolia showed significant qualitative and quantitative variations. LC-MS and MS/MS methods can be used to differentiate between male and female plants based on their chemical profiles and quantities of the marker bioactive alkaloids. This chemical composition difference was also evident during vegetative stage when there were no male and female flowers. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Microdose study of a P-glycoprotein substrate, fexofenadine, using a non-radioisotope-labelled drug and LC/MS/MS.

    PubMed

    Yamazaki, A; Kumagai, Y; Yamane, N; Tozuka, Z; Sugiyama, Y; Fujita, T; Yokota, S; Maeda, M

    2010-04-01

    Fexofenadine is a P-glycoprotein substrate of low bioavailability. It is primarily excreted into faeces as a parent drug via biliary excretion. The predictability from microdose data for the drug absorbed via transporters such as P-glycoprotein is not known. Therefore, this study assessed the predictability of therapeutic-dose pharmacokinetics of fexofenadine from microdosing data using non-radioisotope-labelled drug and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS). In a single dose, randomized, two-way crossover study, eight subjects received a microdose (100 microg) or a therapeutic dose (60 mg) of fexofenadine. Blood samples were collected until 12 h after dosing, and assayed using LC/MS/MS. Plasma concentration-time curves of fexofenadine between microdose and therapeutic dose were similar. The mean +/- SD of C(max) normalized to 60 mg dose after microdose and therapeutic dose were 379 +/- 147 and 275 +/- 145 ng/mL respectively. The mean AUC(last) normalized to 60 mg dose after microdose and therapeutic dose were 1914 +/- 738 and 1431 +/- 432 ng/h/mL respectively. The mean dose-adjusted C(max) and AUC(last) after microdose were higher compared with those after therapeutic dose. Individual plots of C(max) and AUC(last) normalized to 60 mg dose, were similar for microdose and therapeutic dose. None of the pharmacokinetic parameters were statistically different using anova. Overall, the microdose pharmacokinetics profile was similar to, and hence predictive of, that of the therapeutic dose. For the P-glycoprotein substrate fexofenadine, the predictability of therapeutic-dose pharmacokinetics from microdose data was good. A microdose study using a non-radioisotope-labelled drug and LC/MS/MS is convenient, and has the potential to aid the early selection of drug candidates.

  10. Multiplexed LC-MS/MS analysis of horse plasma proteins to study doping in sport.

    PubMed

    Barton, Chris; Beck, Paul; Kay, Richard; Teale, Phil; Roberts, Jane

    2009-06-01

    The development of protein biomarkers for the indirect detection of doping in horse is a potential solution to doping threats such as gene and protein doping. A method for biomarker candidate discovery in horse plasma is presented using targeted analysis of proteotypic peptides from horse proteins. These peptides were first identified in a novel list of the abundant proteins in horse plasma. To monitor these peptides, an LC-MS/MS method using multiple reaction monitoring was developed to study the quantity of 49 proteins in horse plasma in a single run. The method was optimised and validated, and then applied to a population of race-horses to study protein variance within a population. The method was finally applied to longitudinal time courses of horse plasma collected after administration of an anabolic steroid to demonstrate utility for hypothesis-driven discovery of doping biomarker candidates.

  11. [LC-MS/MS method for determination of tripterine in plasma: pharmacokinetic study in Beagles].

    PubMed

    Zhang, Jun; Liu, Shi-Jia; Hu, Jie-Hui; Xu, Mei-Juan; Liu, Zi-Xiu; Zhou, Ling; Ju, Wen-Zheng

    2016-07-01

    To establish a LC-MS/MS method for determination of tripterine in Beagle plasma and study its pharmacokinetics after oral administration of tripterygium tablet. Plasma samples were extracted with dichloromethane and separated on a Phenomenex Luna C₈ (2.0 mm×50 mm, 3 μm) column with methanol-acetonitrile isopropanol(1∶1)-1‰formic acid (15∶55 ∶30) as the mobile phase. Tripterine ([M+H] ⁺, m/z 451.3/201.1) and internal standard prednisolone ([M+H] ⁺, m/z 361.1/147.1) were monitored in multiple reaction monitoring (MRM). The concentration-time curves were simulated by drug and statistic software 1.0 and the pharmacokinetic parameters were calculated. There was a good linear relationship between peak area ratio and concentration of tripterine and internal standard prednisolone within range of 0.680 0-136.0 μg•L⁻¹. The limit of quantitation was 0.680 0 μg•L⁻¹ and the intra- and inter-day precision was within 6.15%. The absolute recovery rate was between 50.42% to 51.65%. The concentration-time curves were consistent with the one-compartment model(w=1/cc). The main pharmacokinetic parameters after a single dose were as follows: Cmax (35.64±9.540) μg •L⁻¹,Tmax(2.62±0.69) h,T1/2(2.93±0.29) h, CL (0.308±0.056) L•kg⁻¹•h⁻¹, AUC0-12 (131.16±31.94) μg•L•h⁻¹, AUC0-∞ (142.83±37.57) μg•L•h⁻¹. The established LC-MS/MS method was proved to be sensitive, accurate and convenient, suitable for the pharmacokinetic study of Tripterygium tablet in Beagle dogs. Copyright© by the Chinese Pharmaceutical Association.

  12. Automated system for on-line desorption of dried blood spots applied to LC/MS/MS pharmacokinetic study of flurbiprofen and its metabolite.

    PubMed

    Déglon, Julien; Thomas, Aurélien; Daali, Youssef; Lauer, Estelle; Samer, Caroline; Desmeules, Jules; Dayer, Pierre; Mangin, Patrice; Staub, Christian

    2011-01-25

    This paper illustrates the development of an automated system for the on-line bioanalysis of dried blood spots (on-line DBS). In this way, a prototype was designed for integration into a conventional LC/MS/MS, allowing the successive extraction of 30 DBS toward the analytical system without any sample pretreatment. The developed method was assessed for the DBS analysis of flurbiprofen (FLB) and its metabolite 4-hydroxyflurbiprofen (OH-FLB) in human whole blood (i.e. 5 μL). The automated procedure was fully validated based on international criteria and showed good precision, trueness, and linearity over the expected concentration range (from 10 to 1000 ng/mL and 100 to 10,000 ng/mL for OH-FLB and FLB respectively). Furthermore, the prototype showed good results in terms of recovery and carry-over. Stability of both analytes on filter paper was also investigated and the results suggested that DBS could be stored at ambient temperature for over 1 month. The on-line DBS automated system was then successfully applied to a pharmacokinetic study performed on healthy male volunteers after oral administration of a single 50-mg dose of FLB. Additionally, a comparison between finger capillary DBS and classic venous plasma concentrations was investigated. A good correlation was observed, demonstrating the complementarity of both sampling forms. The automated system described in this article represents an efficient tool for the LC/MS/MS analysis of DBS samples in many bioanalytical applications. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. Evaluation of Tamoxifen and metabolites by LC-MS/MS and HPLC Methods

    PubMed Central

    Heath, D.D.; Flatt, S.W.; Wu, A.H.B.; Pruitt, M.A.; Rock, C.L.

    2015-01-01

    Epidemiological and laboratory evidence suggests that quantification of serum or plasma levels of tamoxifen and the metabolites of tamoxifen, 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), Z-4-hydroxy-tamoxifen (4HT), N-desmethyl-tamoxifen (ND-tam) is a clinically useful tool in the assessment and monitoring of breast cancer status in patients taking adjuvant tamoxifen. A liquid chromatographic mass spectrometric method (LC-MS/MS) was used to measure the blood levels of tamoxifen and the metabolites of tamoxifen. This fully automated analytical method is specific, accurate and sensitive. The LC-MS/MS automated technique has now become a widely accepted reference method. We analyzed a randomly selected batch of blood samples from participants enrolled in a breast cancer study to compare results from this reference method in 40 samples with those obtained from a recently developed high performance liquid chromatography (HPLC) method with fluorescence detection. The mean (SD) concentration for the LC-MS/MS (endoxifen 12.6 [7.5] ng/mL, tamoxifen 105 [44] ng/mL, 4-HT 1.9 [1.0] ng/mL, ND-tam 181 [69] ng/mL) and the HPLC (endoxifen 13.1 [7.8] ng/mL, tamoxifen 108[55]ng/mL, 4-HT 1.8 [0.8] ng/mL, ND-tam 184 [81] ng/mL), the methods did not show any significant differences. Our results confirm that the HPLC method offers an accurate and comparable alternative for the quantification of tamoxifen and tamoxifen metabolites. PMID:24693573

  14. Urine Multi-drug Screening with GC-MS or LC-MS-MS Using SALLE-hybrid PPT/SPE.

    PubMed

    Lee, Junhui; Park, Jiwon; Go, Ahra; Moon, Heesung; Kim, Sujin; Jung, Sohee; Jeong, Wonjoon; Chung, Heesun

    2018-05-14

    To intoxicated patients in the emergency room, toxicological analysis can be considerably helpful for identifying the involved toxicants. In order to develop a urine multi-drug screening (UmDS) method, gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) were used to determine targeted and unknown toxicants in urine. A GC-MS method in scan mode was validated for selectivity, limit of detection (LOD) and recovery. An LC-MS-MS multiple reaction monitoring (MRM) method was validated for lower LOD, recovery and matrix effect. The results of the screening analysis were compared with patient medical records to check the reliability of the screen. Urine samples collected from an emergency room were extracted through a combination of salting-out assisted liquid-liquid extraction (SALLE) and hybrid protein precipitation/solid phase extraction (hybrid PPT/SPE) plates and examined by GC-MS and LC-MS-MS. GC-MS analysis was performed as unknown drug screen and LC-MS-MS analysis was conducted as targeted drug screen. After analysis by GC-MS, a library search was conducted using an in-house library established with the automated mass spectral deconvolution and identification system (AMDISTM). LC-MS-MS used Cliquid®2.0 software for data processing and acquisition in MRM mode. An UmDS method by GC-MS and LC-MS-MS was developed by using a SALLE-hybrid PPT/SPE and in-house library. The results of UmDS by GC-MS and LC-MS-MS showed that toxicants could be identified from 185 emergency room patient samples containing unknown toxicants. Zolpidem, acetaminophen and citalopram were the most frequently encountered drugs in emergency room patients. The UmDS analysis developed in this study can be used effectively to detect toxic substances in a short time. Hence, it could be utilized in clinical and forensic toxicology practices.

  15. LC-MS/MS imaging with thermal film-based laser microdissection.

    PubMed

    Oya, Michiko; Suzuki, Hiromi; Anas, Andrea Roxanne J; Oishi, Koichi; Ono, Kenji; Yamaguchi, Shun; Eguchi, Megumi; Sawada, Makoto

    2018-01-01

    Mass spectrometry (MS) imaging is a useful tool for direct and simultaneous visualization of specific molecules. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is used to evaluate the abundance of molecules in tissues using sample homogenates. To date, however, LC-MS/MS has not been utilized as an imaging tool because spatial information is lost during sample preparation. Here we report a new approach for LC-MS/MS imaging using a thermal film-based laser microdissection (LMD) technique. To isolate tissue spots, our LMD system uses a 808-nm near infrared laser, the diameter of which can be freely changed from 2.7 to 500 μm; for imaging purposes in this study, the diameter was fixed at 40 μm, allowing acquisition of LC-MS/MS images at a 40-μm resolution. The isolated spots are arranged on a thermal film at 4.5-mm intervals, corresponding to the well spacing on a 384-well plate. Each tissue spot is handled on the film in such a manner as to maintain its spatial information, allowing it to be extracted separately in its individual well. Using analytical LC-MS/MS in combination with the spatial information of each sample, we can reconstruct LC-MS/MS images. With this imaging technique, we successfully obtained the distributions of pilocarpine, glutamate, γ-aminobutyric acid, acetylcholine, and choline in a cross-section of mouse hippocampus. The protocol we established in this study is applicable to revealing the neurochemistry of pilocarpine model of epilepsy. Our system has a wide range of uses in fields such as biology, pharmacology, pathology, and neuroscience. Graphical abstract Schematic Indication of LMD-LC-MS/MS imaging.

  16. Quantitative determination of mycotoxins in urine by LC-MS/MS.

    PubMed

    Ahn, J; Kim, D; Kim, H; Jahng, K-Y

    2010-12-01

    Naturally occurring mycotoxins are responsible for a wide array of adverse health effects. The measurement of urinary mycotoxin levels is a useful means of assessing an individual's exposure, but the development of sensitive and accurate analytical methods for detecting mycotoxins and their metabolites in urine samples is challenging. Urinary mycotoxins are present in low pg ml⁻¹ concentrations, and the chromatographic identification of their metabolites can be obscured by other endogenous metabolites. We developed an analytical method focused on the selection of two appropriate multiple-reaction monitoring transition for unambiguous identification and quantification of carcinogenic aflatoxin M₁ (AFM₁), ochratoxin A (OTA) and fumonisin B₁, B₂ (FB₁, FB₂) in urine samples from a small volunteer group in a pilot study. AFM₁, OTA, FB₁ and FB₂ were concentrated selectively, interfering substances were removed using an immunoaffinity column (IAC), and mycotoxins were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in combination with a stable-isotope standard-dilution assay (SIDA). The method was sensitive enough to measure mycotoxins and their metabolites at pg ml⁻¹ levels in urine. The combination of LC-MS/MS and SIDA was critical to distinguishing pseudo-OTα interference from genuine OTα. Twelve urine samples contained OTA ranging from 0.013 to 0.093 ng ml⁻¹ (mean = 0.031 ng ml⁻¹). AFM₁ were detected in one sample at a 0.002 ng ml⁻¹ level, while FB₁ and FB₂ were undetectable in all 12 samples. None of the samples in this pilot study contained a detectable level of OTα, despite the presence of OTA, and this may suggest the need for further epidemiological investigation of OTA exposure in the Korean population.

  17. Rapid Quantification of Abscisic Acid by GC-MS/MS for Studies of Abiotic Stress Response.

    PubMed

    Verslues, Paul E

    2017-01-01

    Drought and low water potential induce large increases in Abscisic Acid (ABA ) content of plant tissue. This increased ABA content is essential to regulate downstream stress resistance responses; however, the mechanisms regulating ABA accumulation are incompletely known. Thus, the ability to accurately quantify ABA at high throughput and low cost is important for plant stress research. We have combined and modified several previously published protocols to establish a rapid ABA analysis protocol using gas chromatography-tandem mass spectrometry (GC-MS/MS). Derivatization of ABA is performed with (trimethylsilyl)-diazomethane rather than the harder to prepare diazomethane. Sensitivity of the analysis is sufficient that small samples of low water potential treated Arabidopsis thaliana seedlings can be routinely analyzed in reverse genetic studies of putative stress regulators as well as studies of natural variation in ABA accumulation.

  18. LC-MS/MS based identification of piperine production by endophytic Mycosphaerella sp. PF13 from Piper nigrum.

    PubMed

    Chithra, S; Jasim, B; Anisha, C; Mathew, Jyothis; Radhakrishnan, E K

    2014-05-01

    Piper nigrum is very remarkable for its medicinal properties due to the presence of metabolites like piperine. Emerging understanding on the biosynthetic potential of endophytic fungi suggests the possibility to have piperine producing fungi in P. nigrum. In the current study, endophytic fungi isolated from P. nigrum were screened for the presence of piperine by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This resulted in the identification of a Mycosphaerella sp. with the ability to produce piperine extracellularly. The biosynthesis of piperine (C17H19NO3) by the endophytic fungal isolate was confirmed by the presence of m/z 286.1 (M + H(+)) in the LC-MS/MS analysis using positive mode ionization. This was further supported by the presence of specific fragment ions with masses 135, 143, 171 and 201 formed due to the fragmentation of piperine present in the fungal extract.

  19. Simultaneous determination of cucurbitacin B and cucurbitacin E in rat plasma by UHPLC-MS/MS: A pharmacokinetics study after oral administration of cucurbitacin tablets.

    PubMed

    Wang, Zhibin; Zhu, Wenbo; Gao, Mingjie; Wu, Chengcui; Yang, Chunjuan; Yang, Jing; Wu, Gaosong; Yang, Bingyou; Kuang, Haixue

    2017-10-15

    Cucurbitacin B (CuB) and cucurbitacin E (CuE) are tetracyclic triterpene compounds from Cucurbitaceae, and the main bioactive compounds of cucurbitacins tablets that used to treatment of chronic hepatitis. Pharmacological research has been very comprehensive, and there are few studies on pharmacokinetics, especially about CuE. An Ultra High Performance Liquid Chromatography-tandem Mass Spectrometry (UHPLC-MS/MS) method with high selectivity, simplicity and sensitivity has been used for quantitative analysis of Cucurbitacin B (CuB) and cucurbitacin E (CuE). Plasma samples were pretreatment by Liquid-liquid extraction (LLE) method with dichloromethane. The chromatographic separation was achieved on a C 18 column (Agilent Eclipse Plus, 1.8μm, 50×2.1mm) using gradient elution with water - methanol at a flow rate of 0.3mL/min and the column temperature was set at 30°C. The method was validated according to FDA guidelines. Lower limit of quantification (LLOQ) was 1.60ng/mL for CuB and 1.58ng/mL for CuE. Correlation coefficients of CuB and CuE were more than 0.99 in rat plasma. All values of intra-day and inter-day precision (RSD%) were not exceeded 15%, the accuracy (RE%) were within -5.57 to 5.20% for CuB and -3.33 to 7.37% for CuE. The mean extraction recoveries were more than 80%. Pharmacokinetic parameters were also evaluated by UHPLC-MS/MS method. The results suggestion that this method was successfully applied to pharmacokinetic study of CuB and CuE in rat plasma after oral administration cucurbitacin tablets. Published by Elsevier B.V.

  20. Backscatter Mossbauer Spectrometer (BaMS) for extraterrestrial applications

    NASA Technical Reports Server (NTRS)

    Agresti, D. G.; Shelfer, T. D.; Pimperl, M. M.; Wills, E. L.; Shen, M. H.; Morris, R. V.

    1993-01-01

    Mossbauer spectroscopy is a nuclear gamma resonance technique particularly well suited to the study of materials that contain iron (Fe-57). It can provide information on the oxidation state of iron as well as the type and proportion of iron-containing mineral species in a sample of interest. Iron Mossbauer spectroscopy (FeMS) has been applied to samples believed to have come from Mars (SNC meteorites) and has been helpful in refining the choice among putative Martian surface materials by suggesting a likely nanophase component of the Martian regolity. FeMS spectrum of a Martial analogue material (Hawaiian palagonite) is shown; it is dominated by ferric-bearing phases and shows evidence of a nanophase component. FeMS has also been applied to lunar materials. It can be used to measure the maturity of lunar surface material and has been proposed as a prospector for lunar ilmenite, an oxygen resource mineral. Several years ago we suggested a backscatter Mossbauer spectrometer (BaMS) for a Mars rover mission. Backscatter design was selected as most appropriate for in-situ application because no sample preparation is required. Since that time, we have continued to develop the BaMS instrument in anticipation that it would eventually find a home on a NASA planetary mission. Gooding proposed BaMS as a geochemistry instrument on MESUR. More recently, an LPI workshop has recommended that BaMS be included in a three-instrument payload on the next (1996?) lunar lander.

  1. PyMS: a Python toolkit for processing of gas chromatography-mass spectrometry (GC-MS) data. Application and comparative study of selected tools.

    PubMed

    O'Callaghan, Sean; De Souza, David P; Isaac, Andrew; Wang, Qiao; Hodkinson, Luke; Olshansky, Moshe; Erwin, Tim; Appelbe, Bill; Tull, Dedreia L; Roessner, Ute; Bacic, Antony; McConville, Malcolm J; Likić, Vladimir A

    2012-05-30

    Gas chromatography-mass spectrometry (GC-MS) is a technique frequently used in targeted and non-targeted measurements of metabolites. Most existing software tools for processing of raw instrument GC-MS data tightly integrate data processing methods with graphical user interface facilitating interactive data processing. While interactive processing remains critically important in GC-MS applications, high-throughput studies increasingly dictate the need for command line tools, suitable for scripting of high-throughput, customized processing pipelines. PyMS comprises a library of functions for processing of instrument GC-MS data developed in Python. PyMS currently provides a complete set of GC-MS processing functions, including reading of standard data formats (ANDI- MS/NetCDF and JCAMP-DX), noise smoothing, baseline correction, peak detection, peak deconvolution, peak integration, and peak alignment by dynamic programming. A novel common ion single quantitation algorithm allows automated, accurate quantitation of GC-MS electron impact (EI) fragmentation spectra when a large number of experiments are being analyzed. PyMS implements parallel processing for by-row and by-column data processing tasks based on Message Passing Interface (MPI), allowing processing to scale on multiple CPUs in distributed computing environments. A set of specifically designed experiments was performed in-house and used to comparatively evaluate the performance of PyMS and three widely used software packages for GC-MS data processing (AMDIS, AnalyzerPro, and XCMS). PyMS is a novel software package for the processing of raw GC-MS data, particularly suitable for scripting of customized processing pipelines and for data processing in batch mode. PyMS provides limited graphical capabilities and can be used both for routine data processing and interactive/exploratory data analysis. In real-life GC-MS data processing scenarios PyMS performs as well or better than leading software packages. We

  2. PyMS: a Python toolkit for processing of gas chromatography-mass spectrometry (GC-MS) data. Application and comparative study of selected tools

    PubMed Central

    2012-01-01

    Background Gas chromatography–mass spectrometry (GC-MS) is a technique frequently used in targeted and non-targeted measurements of metabolites. Most existing software tools for processing of raw instrument GC-MS data tightly integrate data processing methods with graphical user interface facilitating interactive data processing. While interactive processing remains critically important in GC-MS applications, high-throughput studies increasingly dictate the need for command line tools, suitable for scripting of high-throughput, customized processing pipelines. Results PyMS comprises a library of functions for processing of instrument GC-MS data developed in Python. PyMS currently provides a complete set of GC-MS processing functions, including reading of standard data formats (ANDI- MS/NetCDF and JCAMP-DX), noise smoothing, baseline correction, peak detection, peak deconvolution, peak integration, and peak alignment by dynamic programming. A novel common ion single quantitation algorithm allows automated, accurate quantitation of GC-MS electron impact (EI) fragmentation spectra when a large number of experiments are being analyzed. PyMS implements parallel processing for by-row and by-column data processing tasks based on Message Passing Interface (MPI), allowing processing to scale on multiple CPUs in distributed computing environments. A set of specifically designed experiments was performed in-house and used to comparatively evaluate the performance of PyMS and three widely used software packages for GC-MS data processing (AMDIS, AnalyzerPro, and XCMS). Conclusions PyMS is a novel software package for the processing of raw GC-MS data, particularly suitable for scripting of customized processing pipelines and for data processing in batch mode. PyMS provides limited graphical capabilities and can be used both for routine data processing and interactive/exploratory data analysis. In real-life GC-MS data processing scenarios PyMS performs as well or better than

  3. A quantitative determination of fluorochloridone in rat plasma by UPLC-MS/MS method: application to a pharmacokinetic study.

    PubMed

    Liu, Shihong; Shi, Jingmin; Fan, Junpei; Sun, Jie; Zhang, Suhui; Hu, Yue; Wei, Li; Wu, Chunhua; Chang, Xiuli; Tang, Liming; Zhou, Zhijun

    2016-08-01

    A precise, high-throughput and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed for the determination of fluorochloridone (FLC) in rat plasma. The extraction of analytes from plasma samples was carried out by protein precipitation procedure using acetonitrile prior to UPLC-MS/MS analysis. Verapamil was proved as a proper internal standard (IS) among many candidates. The chromatographic separation based on UPLC was well optimized. Multiple reaction monitoring in positive electrospray ionization was used with the optimized MS transitions at: m/z 312.0 → 292.0 for FLC and m/z 456.4 → 165.2 for IS. This method was well validated with good linear response (r(2)  > 0.998) observed over the investigated range of 3-3000 ng/mL and with satisfactory stability. This method was also characterized with adequate intra- and inter-day precision and accuracy (within 12%) in the quality control samples, and with high selectivity and less matrix effect observed. Total running time was only 1.5 min. This method has been successfully applied to a pilot FLC pharmacokinetic study after oral administration. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Pharmacokinetic and ocular microdialysis study of oral ginkgo biloba extract in rabbits by UPLC-MS/MS determination.

    PubMed

    Wang, Shuya; Li, Ding; Pi, Jiaxin; Li, Wen; Zhang, Bing; Qi, Dongli; Li, Nan; Guo, Pan; Liu, Zhidong

    2017-11-01

    The purpose of this work was to determine and investigate the absorption of ginkgo terpenoids (GT) in plasma and aqueous humour after oral administration of ginkgo biloba extract (GBE) by UPLC-MS/MS method. The UPLC-MS/MS determination of GT employed the multiple reaction monitoring mode using an electrospray negative ionization. The rabbits were orally administered the suspension of GBE at a dose of 500 mg/kg. Serial plasma and dialysate samples were collected at the corresponding time and then analysed by UPLC-MS/MS. In plasma, the mean AUC from 0 to 48 h was 14.12, 12.59, 23.75, 1.51 h μg/ml for GLJ and 5.34 h μg/ml for GLA, GLB, GLC, GLJ and BLL, respectively. In aqueous humour, the five ginkgo terpenoids have been detected. Compared with the other four GT, BLL has better absorption in the eyes. A selective and reproducible UPLC-MS/MS method was developed and validated to determine and investigate the absorption of ginkgo terpenoids in plasma and aqueous humour of rabbits after oral administration of GBE. The main five ginkgo terpenoids could be absorbed into eyes. © 2017 Royal Pharmaceutical Society.

  5. A lead isotope distribution study in swine tissue using ICP-MS

    USGS Publications Warehouse

    May, T.W.; Wiedmeyer, Ray H.; Brown, L.D.; Casteel, S.W.

    1999-01-01

    In the United States lead is an ubiquitous environmental pollutant that is a serious human health hazard, especially for women of childbearing age, developing fetuses, and young children. Information concerning the uptake and distribution of lead to maternal and fetal tissues during pregnancy is poorly documented. A study was designed using domestic swine and lead isotope enrichment methodology to focus on maternal absorption and distribution of lead into bone and soft tissues, including the fetal compartment, under varying conditions of oral lead exposure and during altered physiological states (pregnant vs unbred). Total lead levels and Pb207/Pb206 ratios in bone (femur and vertebra), blood, and soft tissues (liver, kidney, brain) were determined by ICP-MS. Lead in fetal tissues derived from maternal bone could be differentiated from that derived from exogenous dosing. Unbred swine absorbed much less lead than pregnant females receiving the same dose. The accuracy and precision of ICP-MS at the instrumental level and for the entire method (sample collection, digestion, and analysis) were evaluated for both Pb207/Pb206 ratios and total lead. Several changes were suggested in method design to improve both instrumental and total method precision.

  6. Simultaneous determination of ornidazole and its main metabolites in human plasma by LC-MS/MS: application to a pharmacokinetic study.

    PubMed

    Du, Jiangbo; Ma, Zhiyu; Zhang, Yifan; Wang, Ting; Chen, Xiaoyan; Zhong, Dafang

    2014-09-01

    Ornidazole is a 5-nitroimidazole antimicrobial agent used for almost 40 years. A novel LC-MS/MS assay was developed and validated for the simultaneous determination of ornidazole and its main metabolites (M3, M6, M16-1, and M16-2) in human plasma. After extraction from 100 μl of plasma by protein precipitation with acetonitrile, all the analytes were separated on a Capcell PAK MG C18 column (100 × 4.6 mm, 5 μm) within 5.0 min and detected by ESI-MS/MS in the positive mode. The validation results met the acceptance criteria as per the US FDA and EMA guidelines. The validated method was successfully applied to a pharmacokinetic study after oral administration of 1000 mg ornidazole to six healthy Chinese volunteers.

  7. Development and comparison of HPLC-MS/MS and UPLC-MS/MS methods for determining eight coccidiostats in beef.

    PubMed

    Zhao, Xia; Wang, Bo; Xie, Kaizhou; Liu, Jianyu; Zhang, Yangyang; Wang, Yajuan; Guo, Yawen; Zhang, Genxi; Dai, Guojun; Wang, Jinyu

    2018-06-15

    A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method and an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determining eight coccidiostat (halofuginone, lasalocid, maduramicin, monensin, narasin, nigericin, robenidine and salinomycin) residues in beef were developed and compared. Samples were extracted with a mixture of acetic acid, acetonitrile and ethyl acetate and were then purified on a C 18 solid-phase extraction (SPE) column. The purified samples were analyzed by HPLC-MS/MS and UPLC-MS/MS, using 0.1% formic acid-water solution (A) and pure methanol (B) as the mobile phase. The samples were fractionated on a C 18 column using different gradient elution procedures, followed by qualitative analysis using a mass spectrometer operated in multiple reaction monitoring (MRM) mode with positive electrospray ionization; the external standard method was used for quantitation. At spiked levels that ranged from the limit of quantification (LOQ) to 100 μg/kg, the average recoveries were 71.96%-100.32% and 71.24%-89.24%, with relative standard deviations (RSDs) of 2.65%-12.38% and 2.98%-14.86% for UPLC-MS/MS and HPLC-MS/MS, respectively. The limits of detection (LODs) and LOQs of the eight coccidiostats were 0.14-0.32 μg/kg and 0.43-1.21 μg/kg, respectively, for UPLC-MS/MS analysis and 0.16-0.58 μg/kg and 0.53-1.92 μg/kg, respectively, for HPLC-MS/MS analysis. Both methods had good accuracy and precision, but UPLC-MS/MS had higher sensitivity than HPLC-MS/MS. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Development of an LC/MS/MS method in order to determine arctigenin in rat plasma: its application to a pharmacokinetic study.

    PubMed

    Zou, Quanfei; Gu, Yuan; Lu, Rong; Zhang, Tiejun; Zhao, Guang-Rong; Liu, Changxiao; Si, Duanyun

    2013-09-01

    In this study, a simple and sensitive LC/MS/MS method was developed and validated for the determination of arctigenin in rat plasma. The MS detection was performed using multiple reaction monitoring at the transitions of m/z 373.2 → 137.3 for arctigenin and m/z 187.1 → 131.0 for psoralen (internal standard) with a Turbo IonSpray electrospray in positive mode. The calibration curves fitted a good linear relationship over the concentration range of 0.2-500 ng/mL. It was found that arctigenin is not stable enough at both room temperature and -80 °C unless mixed with methanol before storage. The validated LC/MS/MS method was successfully applied for the pharmacokinetic study of arctigenin in rats. After intravenous injection of 0.3 mg/kg arctigenin injection to rats, the maximum concentration, half-life and area under the concentration-time curve were 323 ± 65.2 ng/mL, 0.830 ± 0.166 and 81.0 ± 22.1 h ng/mL, respectively. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Bisphenol A release from an orthodontic resin composite: A GC/MS and LC/MS study.

    PubMed

    Deviot, Marc; Lachaise, Isabelle; Högg, Christof; Durner, Jürgen; Reichl, Franz-Xaver; Attal, Jean-Pierre; Dursun, Elisabeth

    2018-02-01

    First, to analyse the in vitro release of BPA and Bis-GMA from an orthodontic resin composite (Transbond XT, 3M Unitek), stored in various conditions, by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS); then to extrapolate the data to the clinical situation. Secondly, to explore the thermal stability of Bis-GMA. Cylinders of resin composite were prepared and stored according to 3 different protocols: (1) they were light-cured 20s, then placed in artificial saliva; (2) they were light-cured 2s, then placed in acetonitrile; (3) they were light-cured 2s, then placed in methanol. For each group, BPA and Bis-GMA release were determined with GC/MS and/or LC/MS at least after one week. Besides, 120 brackets (10 of each type) were bonded over metal teeth, then debonded, and the weight and the surface of resin composite residues were measured. BPA and Bis-GMA release of adhesive residues were extrapolated from the data obtained with the cylinders. Besides, BPA release from a heated Bis-GMA solution was measured. With GC/MC, BPA was detected in all samples. With LC/MS, BPA was detected only from samples immersed in MeOH; Bis-GMA was detected, in varying amount according to the extraction media and the light-curing time. BPA was found after heating of the Bis-GMA solution. Contamination risk and the heat applied in GC/MS may overestimate the BPA release from resin composite. Based on the LC/MS results, the risk of BPA release after orthodontic bonding would be more than 42000 times lower than the TDI for a 30-kg child. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Pharmacokinetic Evaluation of Empagliflozin in Healthy Egyptian Volunteers Using LC-MS/MS and Comparison with Other Ethnic Populations.

    PubMed

    Ayoub, Bassam M; Mowaka, Shereen; Elzanfaly, Eman S; Ashoush, Nermeen; Elmazar, Mohamed M; Mousa, Shaker A

    2017-05-31

    The present study considered the pharmacokinetic evaluation of empagliflozin after administration to Egyptian volunteers, and the results were compared with other ethnic populations. The FDA recognizes that standard methods of defining racial subgroups are necessary to compare results across pharmacokinetic studies and to assess potential subgroup differences. The design of the study was as an open labeled, randomized, one treatment, one period, single dose pharmacokinetic study. The main pharmacokinetic parameters estimated were C max , T max , t 1/2 , elimination rate constant, AUC 0-t and AUC 0-inf . The insignificant difference in pharmacokinetic parameters between Egyptians and white German subjects suggests that no dose adjustment should be considered with administration of 25 mg empagliflozin to Egyptian population. A new LC-MS/MS method was developed and validated, allowing sensitive estimation of empagliflozin (25-600 ng mL -1 ) in human plasma using dapagliflozin as an internal standard (IS). The method was applied successfully on the underlying pharmacokinetic study with enhanced sample preparation that involved liquid-liquid extraction. Multiple Reaction Monitoring (MRM) of the transition pairs of m/z 449.01 to 371.21 for empagliflozin and m/z 407.00 to 328.81 for dapagliflozin (IS) was employed utilizing negative mode Electro Spray Ionization (ESI). The validated LC-MS/MS method is suitable for further toxicodynamic and bioequivalence studies.

  11. A Proof of Concept to Bridge the Gap between Mass Spectrometry Imaging, Protein Identification and Relative Quantitation: MSI~LC-MS/MS-LF.

    PubMed

    Théron, Laëtitia; Centeno, Delphine; Coudy-Gandilhon, Cécile; Pujos-Guillot, Estelle; Astruc, Thierry; Rémond, Didier; Barthelemy, Jean-Claude; Roche, Frédéric; Feasson, Léonard; Hébraud, Michel; Béchet, Daniel; Chambon, Christophe

    2016-10-26

    Mass spectrometry imaging (MSI) is a powerful tool to visualize the spatial distribution of molecules on a tissue section. The main limitation of MALDI-MSI of proteins is the lack of direct identification. Therefore, this study focuses on a MSI~LC-MS/MS-LF workflow to link the results from MALDI-MSI with potential peak identification and label-free quantitation, using only one tissue section. At first, we studied the impact of matrix deposition and laser ablation on protein extraction from the tissue section. Then, we did a back-correlation of the m / z of the proteins detected by MALDI-MSI to those identified by label-free quantitation. This allowed us to compare the label-free quantitation of proteins obtained in LC-MS/MS with the peak intensities observed in MALDI-MSI. We managed to link identification to nine peaks observed by MALDI-MSI. The results showed that the MSI~LC-MS/MS-LF workflow (i) allowed us to study a representative muscle proteome compared to a classical bottom-up workflow; and (ii) was sparsely impacted by matrix deposition and laser ablation. This workflow, performed as a proof-of-concept, suggests that a single tissue section can be used to perform MALDI-MSI and protein extraction, identification, and relative quantitation.

  12. A Proof of Concept to Bridge the Gap between Mass Spectrometry Imaging, Protein Identification and Relative Quantitation: MSI~LC-MS/MS-LF

    PubMed Central

    Théron, Laëtitia; Centeno, Delphine; Coudy-Gandilhon, Cécile; Pujos-Guillot, Estelle; Astruc, Thierry; Rémond, Didier; Barthelemy, Jean-Claude; Roche, Frédéric; Feasson, Léonard; Hébraud, Michel; Béchet, Daniel; Chambon, Christophe

    2016-01-01

    Mass spectrometry imaging (MSI) is a powerful tool to visualize the spatial distribution of molecules on a tissue section. The main limitation of MALDI-MSI of proteins is the lack of direct identification. Therefore, this study focuses on a MSI~LC-MS/MS-LF workflow to link the results from MALDI-MSI with potential peak identification and label-free quantitation, using only one tissue section. At first, we studied the impact of matrix deposition and laser ablation on protein extraction from the tissue section. Then, we did a back-correlation of the m/z of the proteins detected by MALDI-MSI to those identified by label-free quantitation. This allowed us to compare the label-free quantitation of proteins obtained in LC-MS/MS with the peak intensities observed in MALDI-MSI. We managed to link identification to nine peaks observed by MALDI-MSI. The results showed that the MSI~LC-MS/MS-LF workflow (i) allowed us to study a representative muscle proteome compared to a classical bottom-up workflow; and (ii) was sparsely impacted by matrix deposition and laser ablation. This workflow, performed as a proof-of-concept, suggests that a single tissue section can be used to perform MALDI-MSI and protein extraction, identification, and relative quantitation. PMID:28248242

  13. A preliminary study on postmortem interval estimation of suffocated rats by GC-MS/MS-based plasma metabolic profiling.

    PubMed

    Sato, Takako; Zaitsu, Kei; Tsuboi, Kento; Nomura, Masakatsu; Kusano, Maiko; Shima, Noriaki; Abe, Shuntaro; Ishii, Akira; Tsuchihashi, Hitoshi; Suzuki, Koichi

    2015-05-01

    Estimation of postmortem interval (PMI) is an important goal in judicial autopsy. Although many approaches can estimate PMI through physical findings and biochemical tests, accurate PMI calculation by these conventional methods remains difficult because PMI is readily affected by surrounding conditions, such as ambient temperature and humidity. In this study, Sprague-Dawley (SD) rats (10 weeks) were sacrificed by suffocation, and blood was collected by dissection at various time intervals (0, 3, 6, 12, 24, and 48 h; n = 6) after death. A total of 70 endogenous metabolites were detected in plasma by gas chromatography-tandem mass spectrometry (GC-MS/MS). Each time group was separated from each other on the principal component analysis (PCA) score plot, suggesting that the various endogenous metabolites changed with time after death. To prepare a prediction model of a PMI, a partial least squares (or projection to latent structure, PLS) regression model was constructed using the levels of significantly different metabolites determined by variable importance in the projection (VIP) score and the Kruskal-Wallis test (P < 0.05). Because the constructed PLS regression model could successfully predict each PMI, this model was validated with another validation set (n = 3). In conclusion, plasma metabolic profiling demonstrated its ability to successfully estimate PMI under a certain condition. This result can be considered to be the first step for using the metabolomics method in future forensic casework.

  14. Photodegradation of the fungicide thiram in aqueous solutions. Kinetic studies and identification of the photodegradation products by HPLC-MS/MS.

    PubMed

    Filipe, O M S; Santos, Sónia A O; Domingues, M Rosário M; Vidal, M M; Silvestre, A J D; Neto, C P; Santos, E B H

    2013-05-01

    In this study, the relevance of photodegradation processes on the persistence of the fungicide thiram in waters was investigated. The photodegradation of thiram in Milli-Q water and in aqueous solutions of humic and fulvic acids, as well as the photodegradation in spiked river water were studied. Both pure thiram and one of its commercial formulations were used to prepare the solutions which were irradiated in a solar light simulator. In general, thiram photodegradation follows pseudo-first order kinetics. The half-life time of thiram 2mgL(-1) in Milli-Q water was 28min. However, the degradation rate of thiram was significantly increased (p=0.02) by the inert components of the thiram commercial formulation as well as by commercial humic acids and by fulvic acids isolated from river water (p<0.004). Thus, the half-life time of thiram decreased to 24min in the presence of the inert formulation components, while, in the presence of both humic and fulvic acids (10mgL(-1)) it decreased to 22min. Furthermore, thiram photodegradation in natural river water showed that there is a significant enhancement of the degradation rate constant of thiram relatively to Milli-Q water, corresponding to a decrease of about 38% in its half-life time. This increase of the degradation rate in river water seems to be higher than that observed in the presence of FA, suggesting that beyond organic matter, other natural river components can increase the thiram photodegradation rate. These results allow us to conclude that photodegradation by solar radiation can be an important degradation pathway of thiram in natural waters. HPLC-MS/MS allowed to identify, for the first time, three products of the photodegradation of thiram in aqueous solution. Three compounds were identified and their structure was corroborated by the MS(n) spectra fragmentation profile. Pathways for the formation of the products from thiram photodegradation are proposed and discussed. Copyright © 2013 Elsevier Ltd. All

  15. Characterization, stoichiometry, and stability of salivary protein-tannin complexes by ESI-MS and ESI-MS/MS.

    PubMed

    Canon, Francis; Paté, Franck; Meudec, Emmanuelle; Marlin, Thérèse; Cheynier, Véronique; Giuliani, Alexandre; Sarni-Manchado, Pascale

    2009-12-01

    Numerous protein-polyphenol interactions occur in biological and food domains particularly involving proline-rich proteins, which are representative of the intrinsically unstructured protein group (IUP). Noncovalent protein-ligand complexes are readily detected by electrospray ionization mass spectrometry (ESI-MS), which also gives access to ligand binding stoichiometry. Surprisingly, the study of interactions between polyphenolic molecules and proteins is still an area where ESI-MS has poorly benefited, whereas it has been extensively applied to the detection of noncovalent complexes. Electrospray ionization mass spectrometry has been applied to the detection and the characterization of the complexes formed between tannins and a human salivary proline-rich protein (PRP), namely IB5. The study of the complex stability was achieved by low-energy collision-induced dissociation (CID) measurements, which are commonly implemented using triple quadrupole, hybrid quadrupole time-of-flight, or ion trap instruments. Complexes composed of IB5 bound to a model polyphenol EgCG have been detected by ESI-MS and further analyzed by MS/MS. Mild ESI interface conditions allowed us to observe intact noncovalent PRP-tannin complexes with stoichiometries ranging from 1:1 to 1:5. Thus, ESI-MS shows its efficiency for (1) the study of PRP-tannin interactions, (2) the determination of stoichiometry, and (3) the study of complex stability. We were able to establish unambiguously both their stoichiometries and their overall subunit architecture via tandem mass spectrometry and solution disruption experiments. Our results prove that IB5.EgCG complexes are maintained intact in the gas phase.

  16. Analysis of Thiodiglycol: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS777

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Owens, J; Koester, C

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method for the analysis of thiodiglycol, the breakdown product of the sulfur mustard HD, in water by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), titled Method EPA MS777 (hereafter referred to as EPA CRL SOP MS777). This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to verifymore » the analytical procedures described in MS777 for analysis of thiodiglycol in aqueous samples. The gathered data from this study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of Method EPA MS777 can be determined.« less

  17. Multiple sclerosis (MS) in the life cycle of the family: An interpretative phenomenological analysis of the perspective of persons with recently diagnosed MS.

    PubMed

    de Ceuninck van Capelle, Archie; Visser, Leo H; Vosman, Frans

    2016-12-01

    In this study the authors explored how people with recently diagnosed multiple sclerosis (MS) experience their disease within their family lives. Ten people in various stages of the cycle of family life (leaving home, finding a partner, raising children, parenting adolescents, launching children) who had been diagnosed with MS were interviewed in half-structured conversational interviews. Transcriptions were analyzed following a phenomenological approach. Five themes were found: (a) dwindling capacity for housekeeping and childcare (b) struggling to ask for or to accept help, (c) countering awkward attitudes toward my illness, (d) suspecting family members of concealing their, and (e) watching family members wrestle with your illness. The participants described that their illness affected their ability to care for their family and home as they used to. Only a couple of studies have addressed the first person perspective of patients on family and MS. The study expands on these studies by exploring not previously examined perspectives on leaving home, finding a partner, parenting adolescents, and launching children. The findings on family and MS, approached as elements of the first person perspective of MS patients, may guide future research. Given the pivotal role of worries on family in patient experience of MS, we argue that acknowledgment of family as a constitutive element of the patient perspective should be integrated in regular MS care. The authors suggest that the clinical handling of MS as a family issue needs to be done thoughtfully and with attention to the specifics of each unique family situation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. [Simultaneous determination of daphnetin, daphnoretin, daphneticin in rat plasma by LC-MS/MS and its application in pharmacokinetic study].

    PubMed

    Hu, Yi-Yi-Li-Ge-Qi; Cao, Sa-Li; Lin, Long-Fei; Fu, Jing; Dong, Xiao-Xu; Yang, Chun-Jing; Zhang, Miao; Ni, Jian

    2017-05-01

    To establish HPLC-MS/MS method for simultaneous determination of daphnetin, daphnoretin, and daphneticin in rat plasma after oral and intravenous administration of Daphne giraldii extract, and then use them in the calculation of pharmacokinetic parameters. Six sprague-dawley rats received intragastric administration of D. giraldii extract (daphnetin, daphnoretin and daphneticin were 88.40, 3.24 and 4.28 mg•kg⁻¹, respectively). Their drug plasma concentration was determined by LC-MS/MS with schisandrin as an internal standard to draw plasma concentration-time curve. The pharmacokinetic parameters were calculated by Kinetica 4.4. The results showed that the linear range was 5-1 000 μg•L⁻¹ for daphnetin, daphnoretin and daphneticin, and the method ological test showed conformance to the requirements.The intraday and inter-day variable coefficients (RSD) were both less than 15.0%, indicating that both of legitimate precise and accuracy were consistent with the analysis requirements of biological samples. For daphnetin, the pharmacokinetic parameters Tmax, Cmax, AUC0-t, T1/2 and MRT were 4 h, 858.96 μg•L⁻¹, 10 566.4 μg•L⁻¹•h, 5.19 h and 9.43 h, respectively. For daphnoretin, the pharmacokinetic parameters Tmax, Cmax, AUC0-t, T1/2 and MRT were 2.92 h, 178.00 μg•L⁻¹, 905.89 μg•L⁻¹•h, 3.50 h and 6.95 h, respectively. For daphneticin, the pharmacokinetic parameters Tmax, Cmax, AUC0-t, T1/2 and MRT were 2 h, 36.67 μg•L⁻¹, 355.11 μg•L⁻¹•h, 4.95 h and 8.27 h, respectively. The LC-MS/MS analysis method established in this study was proved to be so accurate and sensitive that it can be applied to the pharmacokinetic study of daphnetin, daphnoretin and daphneticin. Copyright© by the Chinese Pharmaceutical Association.

  19. Simultaneous determination of leucine, isoleucine and valine in Beagle dog plasma by HPLC-MS/MS and its application to a pharmacokinetic study.

    PubMed

    Wang, Ting; Xie, Huiru; Chen, Xu; Jiang, Xuehua; Wang, Ling

    2015-10-10

    Leucine (Leu), isoleucine (Ile) and valine (Val) are three branched-chain amino acids (BCAAs), which have been widely used as dietary supplements for professional athletes and patients with liver failure or catabolic diseases. To date, no pharmacokinetic studies of BCAAs in vivo useful for the assessment of clinical effect following daily intake has been reported. Thus in this study, an HPLC-MS/MS method for simultaneous determination of Leu, Ile and Val in Beagle dog plasma using homoarginine as the internal standard was developed and validated in terms of specificity, linearity, precision, accuracy, and stability. This assay method was then applied to a pharmacokinetic study of BCAAs in dogs following oral administration of 0.25 g/kg and 0.50 g/kg BCAAs. The HPLC-MS/MS method was found to be sensitive and reproducible for quantification of BCAAs in dog plasma and successfully applied to the pharmacokinetic study. All these BCAAs were well absorbed with a substantial increase in the plasma concentration after a baseline modification. No statistical significance was identified in different gender group and no drug accumulation was observed following multiple doses. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Definitive screening design enables optimization of LC-ESI-MS/MS parameters in proteomics.

    PubMed

    Aburaya, Shunsuke; Aoki, Wataru; Minakuchi, Hiroyoshi; Ueda, Mitsuyoshi

    2017-12-01

    In proteomics, more than 100,000 peptides are generated from the digestion of human cell lysates. Proteome samples have a broad dynamic range in protein abundance; therefore, it is critical to optimize various parameters of LC-ESI-MS/MS to comprehensively identify these peptides. However, there are many parameters for LC-ESI-MS/MS analysis. In this study, we applied definitive screening design to simultaneously optimize 14 parameters in the operation of monolithic capillary LC-ESI-MS/MS to increase the number of identified proteins and/or the average peak area of MS1. The simultaneous optimization enabled the determination of two-factor interactions between LC and MS. Finally, we found two parameter sets of monolithic capillary LC-ESI-MS/MS that increased the number of identified proteins by 8.1% or the average peak area of MS1 by 67%. The definitive screening design would be highly useful for high-throughput analysis of the best parameter set in LC-ESI-MS/MS systems.

  1. Unassigned MS/MS Spectra: Who Am I?

    PubMed

    Pathan, Mohashin; Samuel, Monisha; Keerthikumar, Shivakumar; Mathivanan, Suresh

    2017-01-01

    Recent advances in high resolution tandem mass spectrometry (MS) has resulted in the accumulation of high quality data. Paralleled with these advances in instrumentation, bioinformatics software have been developed to analyze such quality datasets. In spite of these advances, data analysis in mass spectrometry still remains critical for protein identification. In addition, the complexity of the generated MS/MS spectra, unpredictable nature of peptide fragmentation, sequence annotation errors, and posttranslational modifications has impeded the protein identification process. In a typical MS data analysis, about 60 % of the MS/MS spectra remains unassigned. While some of these could attribute to the low quality of the MS/MS spectra, a proportion can be classified as high quality. Further analysis may reveal how much of the unassigned MS spectra attribute to search space, sequence annotation errors, mutations, and/or posttranslational modifications. In this chapter, the tools used to identify proteins and ways to assign unassigned tandem MS spectra are discussed.

  2. Kidney tissue targeted metabolic profiling of glucocorticoid-induced osteoporosis and the proposed therapeutic effects of Rhizoma Drynariae studied using UHPLC/MS/MS.

    PubMed

    Huang, Yue; Liu, Xinyu; Zhao, Longshan; Li, Famei; Xiong, Zhili

    2014-06-01

    Traditional Chinese medicine and modern science have indicated that there is a close relationship between bone and kidney. In light of this, this project was designed to study the metabolic profiling by UHPLC/MS/MS of glucocorticoid-induced osteoporosis in kidney tissue and the possible therapeutic effects of Rhizoma Drynariae (RD), a classic traditional Chinese medicine, in improving the kidney function and strengthening bone. Twenty-one Wistar rats were divided into three groups: control group (rats before prednisolone inducing), a model group (prednisolone-induced group) and a treatment group (prednisolone-induced rats that were then administered RD ethanol extracts). By using pattern recognition analysis, a significant change in the metabolic profile of kidney tissue samples was observed in the model group and restoration of the profile was observed after the administration of RD ethanol extracts. Some significantly changed biomarkers related to osteoporosis such as sphingolipids (C16 dihydrosphingosine, C18 dihydrosphingosine, C18 phytosphingosine, C20 phytosphingosine), lysophosphatidycholines (C16:0 LPC, C18:0 LPC) and phenylalanine were identified. As a complement to the metabolic profiling of RD in plasma, these biomarkers suggest that kidney damage, cell cytotoxicity and apoptosis exist in osteoporosis rats, which is helpful in further understanding the underlying process of glucocorticoid-induced osetoporosis and the suggested therapeutic effects of RD. The method shows that tissue target metabonomics might provide a powerful tool to further understand the process of disease and the mechanism of therapeutic effect of Chinese medicines. Copyright © 2014 John Wiley & Sons, Ltd.

  3. Application of CE-ICP-MS and CE-ESI-MS/MS for identification of Zn-binding ligands in Goji berries extracts.

    PubMed

    Ruzik, Lena; Kwiatkowski, Piotr

    2018-06-01

    The identification of groups of ligands binding metals is a crucial issue for the better understanding of their bioaccessibility. In the current study, we have intended an approach for identification of Zn-binding ligands based on using capillary electrophoresis combined with inductively coupled plasma mass spectrometry (CE-ICP-MS) and tandem electrospray ionization mass spectrometry (CE-ESI-MS/MS). The approach, which featured the use of the coupling of capillary electrophoresis with inductively coupled plasma mass spectrometry allows to separate and observe zinc ions present in complexes with respect to their size and charge and to identify nine compounds with zinc isotopic profile. CE-ICP-MS provides us with information about presence of zinc species and elemental information about zinc distribution. CE-ESI-MS/MS provide us with information about the most favorable Zn binding ligands: amino acids, flavonols, stilbenoids, fenolic acids and carotenoids. The presented work is the continuation of previous studies based on using LC-ESI-MS/MS, though, now we presented a new solutions with the possibility of changing detectors without changing the separation techniques, what is important without re-optimizing the method. The new presented method allows to identify the zinc-binding ligands in shorter time. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Determination of a selection of synthetic cannabinoids and metabolites in urine by UHPSFC-MS/MS and by UHPLC-MS/MS.

    PubMed

    Berg, Thomas; Kaur, Lakhwinder; Risnes, Anna; Havig, Stine Marie; Karinen, Ritva

    2016-07-01

    Two different analytical techniques, ultra-high performance supercritical fluid chromatography-tandem mass spectrometry (UHPSFC-MS/MS) and reversed phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), were used for the determination of two synthetic cannabinoids and eleven metabolites in urine; AM-2201 N-4-OH-pentyl, AM-2233, JWH-018 N-5-OH-pentyl, JWH-018 N-pentanoic acid, JWH-073 N-4-OH-butyl, JWH-073 N-butanoic acid, JWH-122 N-5-OH-pentyl, MAM-2201, MAM-2201 N-4-OH-pentyl, RCS-4 N-5-OH-pentyl, UR-144 degradant N-pentanoic acid, UR-144 N-4-OH-pentyl, and UR-144 N-pentanoic acid. Sample preparation included a liquid-liquid extraction after deconjugation with ß-glucuronidase. The UHPSFC-MS/MS method used an Acquity UPC(2 TM) BEH column with a mobile phase consisting of CO2 and 0.3% ammonia in methanol, while the UHPLC-MS/MS method used an Acquity UPLC® BEH C18 column with a mobile phase consisting of 5 mM ammonium formate (pH 10.2) and methanol. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions. Deuterated internal standards were used for six of the compounds. Limits of quantification (LOQs) were between 0.04 and 0.4 µg/L. Between-day relative standard deviations at concentrations ≥ LOQ were ≤20%, with biases within ±19%. Recoveries ranged from 40 to 90%. Corrected matrix effects were within 100 ± 10%, except for MAM-2201 with UHPSFC-MS/MS, and for UR-144 N-pentanoic acid and MAM-2201 N-4-OH-pentyl with UHPLC-MS/MS. Elution order obtained by UHPSFC-MS/MS was almost opposite to that obtained by UHPLC-MS/MS, making this instrument setup an interesting combination for screening and confirmation analyses in forensic cases. The UHPLC-MS/MS method has, since August 2014, been successfully used for confirmation of synthetic cannabinoids in urine samples revealing a positive immunoassay screening result. Copyright © 2015

  5. Combined evaluation of personality, risk and coping in MS patients: A step towards individualized treatment choice - The PeRiCoMS-Study I.

    PubMed

    Bsteh, G; Monz, E; Zamarian, L; Hagspiel, S; Hegen, H; Auer, M; Wurth, S; Di Pauli, F; Deisenhammer, F; Berger, T

    2017-05-15

    Multiple sclerosis (MS) is a chronic inflammatory neurological disease requiring disease-modifying treatment (DMT). To provide patients with the optimal individual therapeutic option, treatment recommendations should be based not only on individual disease course and DMT specific benefit-risk estimates, but also on patient's individual characteristics such as personality, risk attitude and coping strategies. However, these characteristics are difficult to objectify in clinical routine practice without the support of appropriate evaluation instruments. To identify and to assemble an objective test battery measuring personality, risk attitude and coping strategies in MS patients. A comprehensive literature search was performed to obtain all questionnaires assessing personality, risk attitude and coping strategies. Availability in German language, validation in a published normative collective and a reliability of >0.70 were required for our purposes. Based on these criteria, we chose the Big-Five-Personality Test, UPPS Impulsive Behaviour Scale, Domain-Specific Risk-Taking scale (DOSPERT), Brief-COPE and Stress & Coping Inventory (SCI). Results were compared to published normative controls of the respective questionnaires. Out of 22 MS patients (7 males, 15 females) participating in this study, 19 (86.4%) completed all questionnaires. The median completion time was 45min (min-max range: 25-60min). The median scores of the MS group were within the average range of published control samples in all questionnaires. We report that traits of personality, risk attitude and coping strategies can be effectively and feasibly tested in MS patients by the instruments used in our exploratory study. There were no differences between MS patients and healthy controls, thus enabling assessment without being influenced by the diagnosis of MS. After validation in a larger cohort the "PeRiCoMS"-battery will be useful as another step towards a more individualized shared

  6. Preliminary study on application of urine amino acids profiling for monitoring of renal tubular injury using GLC-MS.

    PubMed

    Kazubek-Zemke, Maja; Rybka, Jacek; Marchewka, Zofia; Rybka, Wojciech; Pawlik, Krzysztof; Długosz, Anna

    2014-11-14

    The early diagnosis of the nephrotoxic effect of xenobiotics and drugs is still an unsolved problem. Recent studies suggest a correlation between the nephrotoxic activity of xenobiotics and increased concentration of amino acids in urine. The presented study was focused on the application of GLC-MS method for amino acids profiling in human urine as a noninvasive method for monitoring of kidney condition and tubular injury level. The analytic method is based on the conversion of the amino acids present in the sample to tert-butyldimethylsilyl (TBDMS) derivatives and their analysis by gas-liquid chromatography-mass spectrometry (GLC-MS). The procedure of urine sample preparation for chromatographic analysis was optimized. The presence of 12 amino acids in most of the tested healthy human urine samples was detected. The significant differences in the levels of particular amino acids between patients with tubular injury and healthy controls were found, especially for lysine, valine, serine, alanine and leucine (on average 30.0, 7.5, 3.6, 2.9 and 0.5 fold respectively). We found that this approach based on GLC-MS detection can be used in nephrotoxicity studies for urine amino acids monitoring in exposure to xenobiotics and drugs.

  7. Pharmacokinetic study of indocyanine Green after intravenous administration by UPLC-MS/MS.

    PubMed

    Chen, Yu; Chen, Dongxin; Hu, Wenhao; Lin, Guanyang; Huang, Shiyong

    2015-01-01

    Indocyanine Green is widely used in medical diagnosis and to evaluate liver function and other regional blood flows in clinical application or animal experiments. In this work, a sensitive and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of Indocyanine Green in rat plasma was developed and validated. After addition of rutin as an internal standard (IS), protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 753.4→330.2 for Indocyanine Green, and m/z 611.1→303.1 for IS. Calibration plots were linear throughout the range 20-5000 ng/mL for Indocyanine Green in rat plasma. Mean recoveries of Indocyanine Green in rat plasma ranged from 79.5% to 85.4%. RSD of intra-day and inter-day precision were both < 12%. The accuracy of the method was between 95.9% and 113.9%. The method was successfully applied to pharmacokinetic study of Indocyanine Green after intravenous administration.

  8. Pharmacokinetic study of indocyanine Green after intravenous administration by UPLC-MS/MS

    PubMed Central

    Chen, Yu; Chen, Dongxin; Hu, Wenhao; Lin, Guanyang; Huang, Shiyong

    2015-01-01

    Indocyanine Green is widely used in medical diagnosis and to evaluate liver function and other regional blood flows in clinical application or animal experiments. In this work, a sensitive and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of Indocyanine Green in rat plasma was developed and validated. After addition of rutin as an internal standard (IS), protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 753.4→330.2 for Indocyanine Green, and m/z 611.1→303.1 for IS. Calibration plots were linear throughout the range 20-5000 ng/mL for Indocyanine Green in rat plasma. Mean recoveries of Indocyanine Green in rat plasma ranged from 79.5% to 85.4%. RSD of intra-day and inter-day precision were both < 12%. The accuracy of the method was between 95.9% and 113.9%. The method was successfully applied to pharmacokinetic study of Indocyanine Green after intravenous administration. PMID:26629038

  9. Chemical profiling analysis of Maca using UHPLC-ESI-Orbitrap MS coupled with UHPLC-ESI-QqQ MS and the neuroprotective study on its active ingredients

    NASA Astrophysics Data System (ADS)

    Zhou, Yanyan; Li, Peng; Brantner, Adelheid; Wang, Hongjie; Shu, Xinbin; Yang, Jian; Si, Nan; Han, Lingyu; Zhao, Haiyu; Bian, Baolin

    2017-03-01

    Lepidium meyenii (Maca), originated from Peru, has been cultivated widely in China as a popular health care food. However, the chemical and effective studies of Maca were less in-depth, which restricted its application seriously. To ensure the quality of Maca, a feasible and accurate strategy was established. One hundred and sixty compounds including 30 reference standards were identified in 6 fractions of methanol extract of Maca by UHPLC-ESI-Orbitrap MS. Among them, 15 representative active compounds were simultaneously determined in 17 samples by UHPLC-ESI-QqQ MS. The results suggested that Maca from Yunnan province was the potential substitute for the one from Peru. Meanwhile, the neuroprotective effects of Maca were investigated. Three fractions and two pure compounds showed strong activities in the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced zebrafish model. Among them, 80% methanol elution fraction (Fr5) showed significant neuroprotective activity, followed by 100% part (Fr6). The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was a possible mechanism of its neuroprotective effect.

  10. Chemical profiling analysis of Maca using UHPLC-ESI-Orbitrap MS coupled with UHPLC-ESI-QqQ MS and the neuroprotective study on its active ingredients

    PubMed Central

    Zhou, Yanyan; Li, Peng; Brantner, Adelheid; Wang, Hongjie; Shu, Xinbin; Yang, Jian; Si, Nan; Han, Lingyu; Zhao, Haiyu; Bian, Baolin

    2017-01-01

    Lepidium meyenii (Maca), originated from Peru, has been cultivated widely in China as a popular health care food. However, the chemical and effective studies of Maca were less in-depth, which restricted its application seriously. To ensure the quality of Maca, a feasible and accurate strategy was established. One hundred and sixty compounds including 30 reference standards were identified in 6 fractions of methanol extract of Maca by UHPLC-ESI-Orbitrap MS. Among them, 15 representative active compounds were simultaneously determined in 17 samples by UHPLC-ESI-QqQ MS. The results suggested that Maca from Yunnan province was the potential substitute for the one from Peru. Meanwhile, the neuroprotective effects of Maca were investigated. Three fractions and two pure compounds showed strong activities in the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced zebrafish model. Among them, 80% methanol elution fraction (Fr5) showed significant neuroprotective activity, followed by 100% part (Fr6). The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was a possible mechanism of its neuroprotective effect. PMID:28304399

  11. Chemical profiling analysis of Maca using UHPLC-ESI-Orbitrap MS coupled with UHPLC-ESI-QqQ MS and the neuroprotective study on its active ingredients.

    PubMed

    Zhou, Yanyan; Li, Peng; Brantner, Adelheid; Wang, Hongjie; Shu, Xinbin; Yang, Jian; Si, Nan; Han, Lingyu; Zhao, Haiyu; Bian, Baolin

    2017-03-17

    Lepidium meyenii (Maca), originated from Peru, has been cultivated widely in China as a popular health care food. However, the chemical and effective studies of Maca were less in-depth, which restricted its application seriously. To ensure the quality of Maca, a feasible and accurate strategy was established. One hundred and sixty compounds including 30 reference standards were identified in 6 fractions of methanol extract of Maca by UHPLC-ESI-Orbitrap MS. Among them, 15 representative active compounds were simultaneously determined in 17 samples by UHPLC-ESI-QqQ MS. The results suggested that Maca from Yunnan province was the potential substitute for the one from Peru. Meanwhile, the neuroprotective effects of Maca were investigated. Three fractions and two pure compounds showed strong activities in the 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced zebrafish model. Among them, 80% methanol elution fraction (Fr 5 ) showed significant neuroprotective activity, followed by 100% part (Fr 6 ). The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was a possible mechanism of its neuroprotective effect.

  12. Analysis of Ethanolamines: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS888

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Owens, J; Vu, A; Koester, C

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled 'Analysis of Diethanolamine, Triethanolamine, n-Methyldiethanolamine, and n-Ethyldiethanolamine in Water by Single Reaction Monitoring Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS): EPA Method MS888'. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in 'EPA Method MS888' for analysis of themore » listed ethanolamines in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of 'EPA Method MS888' can be determined.« less

  13. Comparison of clonazepam compliance by measurement of urinary concentration by immunoassay and LC-MS/MS in pain management population.

    PubMed

    West, Robert; Pesce, Amadeo; West, Cameron; Crews, Bridgit; Mikel, Charles; Almazan, Perla; Rosenthal, Murray; Latyshev, Sergey

    2010-01-01

    Physicians determine patient compliance with their medications by use of urine drug testing. It is known that measurement of benzodiazepines is limited by immunoassay specificity and cutoff limits and therefore does not offer physicians an accurate picture of their patients' compliance with these medications. A few studies have used lower cutoffs to demonstrate patient compliance. To define more appropriate cutoffs for compliance monitoring of patients prescribed clonazepam as determined using immunoassay and liquid chromatography-tandem mass spectrometry (LC-MS/MS). A diagnostic accuracy study of the urinary excretion of clonazepam. Millennium Laboratories performed measurements on the urinary excretion of pain patients prescribed clonazepam as the indicator test. This benzodiazepine was chosen because it forms one major metabolite, 7-aminoclonazepam which is specific for that drug. Patients whose only benzodiazepine medication was clonazepam were selected as the test population. The Millennium Laboratories test database was filtered first to select patients on clonazepam, then a second filter was used to eliminate patients with any other listed benzodiazepine medications. Samples were tested using the Microgenics DRI benzodiazepine assay with a 200 ng/mL cutoff. The same samples were quantitatively assessed for 7-aminoclonazepam by LC-MS/MS with a cutoff of 40 ng/mL. The results from the immunoassay were scored as positive or negative while the quantitative results from the LC-MS/MS were also scored as positive or negative depending upon their concentration. Samples from 180 patients met these medication criteria. The positivity rates were 21% (38 samples) by immunoassay. The positivity rate was 70% (126 samples) if the LC-MS/MS cutoff was set at 200 ng/mL. However, the positivity rate was 87% (157 samples) if the LC-MS/MS was set at 40 ng/mL. Concentration distributions revealed a significant fraction (7%) in the 40 - 100 ng/mL range. A limitation of the study

  14. LC-MS/MS profiling-based secondary metabolite screening of Myxococcus xanthus.

    PubMed

    Kim, Jiyoung; Choi, Jung Nam; Kim, Pil; Sok, Dai-Eun; Nam, Soo-Wan; Lee, Choong Hwan

    2009-01-01

    Myxobacteria, Gram-negative soil bacteria, are a well-known producer of bioactive secondary metabolites. Therefore, this study presents a methodological approach for the high-throughput screening of secondary metabolites from 4 wild-type Myxococcus xanthus strains. First, electrospray ionization mass spectrometry (ESI-MS) was performed using extracellular crude extracts. As a result, 22 metabolite peaks were detected, and the metabolite profiling was then conducted using the m/z value, retention time, and MS/MS fragmentation pattern analyses. Among the peaks, one unknown compound peak was identified as analogous to the myxalamid A, B, and C series. An analysis of the tandem mass spectrometric fragmentation patterns and HR-MS identified myxalamid K as a new compound derived from M. xanthus. In conclusion, LC-MS/MS-based chemical screening of diverse secondary metabolites would appear to be an effective approach for discovering unknown microbial secondary metabolites.

  15. Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction

    DOE PAGES

    Boiteau, Rene M.; Hoyt, David W.; Nicora, Carrie D.; ...

    2018-01-17

    Here, we introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS 2), and NMR in a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana. The NMR/MS 2 approach is well suited for discovery ofmore » new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases.« less

  16. Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boiteau, Rene M.; Hoyt, David W.; Nicora, Carrie D.

    Here, we introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS 2), and NMR in a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana. The NMR/MS 2 approach is well suited for discovery ofmore » new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases.« less

  17. Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction

    PubMed Central

    Hoyt, David W.; Nicora, Carrie D.; Kinmonth-Schultz, Hannah A.; Ward, Joy K.

    2018-01-01

    We introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS2), and NMR into a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter out the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture, and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana. The NMR/MS2 approach is well suited to the discovery of new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases. PMID:29342073

  18. Simultaneous quantitative analysis of nine vitamin D compounds in human blood using LC-MS/MS.

    PubMed

    Abu Kassim, Nur Sofiah; Gomes, Fabio P; Shaw, Paul Nicholas; Hewavitharana, Amitha K

    2016-01-01

    It has been suggested that each member of the family of vitamin D compounds may have different function(s). Therefore, selective quantification of each compound is important in clinical research. Development and validation attempts of a simultaneous determination method of 12 vitamin D compounds in human blood using precolumn derivatization followed by LC-MS/MS is described. Internal standard calibration with 12 stable isotope labeled analogs was used to correct for matrix effects in MS detector. Nine vitamin D compounds were quantifiable in blood samples with detection limits within femtomole levels. Serum (compared with plasma) was found to be a more suitable sample type, and protein precipitation (compared with saponification) a more effective extraction method for vitamin D assay.

  19. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) for analysis of endogenous steroids in the luteal phase and early pregnancy in dogs: a pilot study.

    PubMed

    Holst, Bodil S; Kushnir, Mark M; Bergquist, Jonas

    2015-12-01

    Blood samples from dogs are often limited in volume, only allowing few steroids to be quantified with immunoassays. In addition, immunoassays may be compromised by interferences such as anti-reagent antibodies. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can be used for the simultaneous quantitation of several steroids. This has not been described in dogs before. The aims were to use LC-MS/MS to study steroid profiles in early pregnancy and luteal phase in dogs, and to determine if differences exist between pregnant (P) and nonpregnant (NP) dogs. Nine female dogs were included, 4 during a NP luteal phase, 4 during a P luteal phase, and one during one NP and one P luteal phase. Blood samples were collected around the time of the LH surge (Day 0) and on Day 26. Serum was analyzed for 5 classes of steroids, including glucocorticoids, androgens, estrogens, pregnanes, and progestins, using LC-MS/MS methods. The concentration of progesterone was significantly higher on Day 26 in P than in NP bitches. Distribution of concentrations of glucocorticoids, androgens, estrogens, or pregnanes in P and NP dogs were not statistically different. The predominating glucocorticoid was cortisol, and dihydroepiandrosterone (DHEA) was the predominating androgen. Concentration of estrone was comparable to oestradiol, whereas concentrations of pregnenolone were higher than those of 17-OH pregnenolone. Only concentration of progesterone differed between P and NP bitches, being significantly higher on Day 26 in P than in NP bitches. LC-MS/MS offers interesting possibilities for studies of canine reproductive endocrinology. © 2015 American Society for Veterinary Clinical Pathology.

  20. Analytical improvements of hybrid LC-MS/MS techniques for the efficient evaluation of emerging contaminants in river waters: a case study of the Henares River (Madrid, Spain).

    PubMed

    Pérez-Parada, Andrés; Gómez-Ramos, María del Mar; Martínez Bueno, María Jesús; Uclés, Samanta; Uclés, Ana; Fernández-Alba, Amadeo R

    2012-02-01

    Instrumental capabilities and software tools of modern hybrid mass spectrometry (MS) instruments such as high-resolution mass spectrometry (HRMS), quadrupole time-of-flight (QTOF), and quadrupole linear ion trap (QLIT) were experimentally investigated for the study of emerging contaminants in Henares River water samples. Automated screening and confirmatory capabilities of QTOF working in full-scan MS and tandem MS (MS/MS) were explored when dealing with real samples. Investigations on the effect of sensitivity and resolution power influence on mass accuracy were studied for the correct assignment of the amoxicillin transformation product 5(R) amoxicillin-diketopiperazine-2',5' as an example of a nontarget compound. On the other hand, a comparison of quantitative and qualitative strategies based on direct injection analysis and off-line solid-phase extraction sample treatment were assayed using two different QLIT instruments for a selected group of emerging contaminants when operating in selected reaction monitoring (SRM) and information-dependent acquisition (IDA) modes. Software-aided screening usually needs a further confirmatory step. Resolving power and MS/MS feature of QTOF showed to confirm/reject most findings in river water, although sensitivity-related limitations are usually found. Superior sensitivity of modern QLIT-MS/MS offered the possibility of direct injection analysis for proper quantitative study of a variety of contaminants, while it simultaneously reduced the matrix effect and increased the reliability of the results. Confirmation of ethylamphetamine, which lacks on a second SRM transition, was accomplished by using the IDA feature. Hybrid MS instruments equipped with high resolution and high sensitivity contributes to enlarge the scope of targeted analytes in river waters. However, in the tested instruments, there is a margin of improvement principally in required sensitivity and data treatment software tools devoted to reliable confirmation

  1. Investigation of epigallocatechin-3-O-caffeoate and epigallocatechin-3-O-p-coumaroate in tea leaves by LC/MS-MS analysis.

    PubMed

    Umehara, Masahiro; Yanae, Koji; Maruki-Uchida, Hiroko; Sai, Masahiko

    2017-12-01

    (-)-Epigallocatechin-3-O-gallate (EGCG), the major catechin present in green tea, exhibits potent antioxidant activity. We thereby investigated the presence of unknown components bearing the (-)-epigallocatechin (EGC) moiety in fresh tea leaf samples. Initially, liquid chromatography tandem mass spectrometry (LC-MS/MS) was employed to examine fresh tea leaves of the Yabukita, the most popular tea cultivar in Japan, which suggested the presence of the EGC phenylpropanoid derivatives, (-)-epigallocatechin-3-O-p-coumaroate (EGCpCA) and (-)-epigallocatechin-3-O-caffeoate (EGCCA). The structures of the detected EGCpCA and EGCCA were then confirmed by LC-MS/MS using synthesized EGCpCA and EGCCA as standards. In addition, EGCpCA and EGCCA were evaluated for their antioxidant activity in the ORAC (oxygen radical antioxidant capacity) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assays, where EGCCA (8.60μmolTE/μmol, TE=Trolox equivalents) exhibited a stronger antioxidant activity than EGCG (5.52μmolTE/μmol) in the ORAC assay. Finally, EGCpCA and EGCCA were quantitated in several tea leaf samples using LC-MS/MS, and it was found that these compounds were present in lower quantities (EGCpCA, 16.8-345.8μg/g, EGCCA, 4.3-75.1μg/g in the dry tea leaves) than the major catechins. In this study, we found the potent antioxidant EGCCA using LC-MS/MS and revealed its wide existence in various tea leaves. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. MS/MS analysis and imaging of lipids across Drosophila brain using secondary ion mass spectrometry.

    PubMed

    Phan, Nhu T N; Munem, Marwa; Ewing, Andrew G; Fletcher, John S

    2017-06-01

    Lipids are abundant biomolecules performing central roles to maintain proper functioning of cells and biological bodies. Due to their highly complex composition, it is critical to obtain information of lipid structures in order to identify particular lipids which are relevant for a biological process or metabolic pathway under study. Among currently available molecular identification techniques, MS/MS in secondary ion mass spectrometry (SIMS) imaging has been of high interest in the bioanalytical community as it allows visualization of intact molecules in biological samples as well as elucidation of their chemical structures. However, there have been few applications using SIMS and MS/MS owing to instrumental challenges for this capability. We performed MS and MS/MS imaging to study the lipid structures of Drosophila brain using the J105 and 40-keV Ar 4000 + gas cluster ion source, with the novelty being the use of MS/MS SIMS analysis of intact lipids in the fly brain. Glycerophospholipids were identified by MS/MS profiling. MS/MS was also used to characterize diglyceride fragment ions and to identify them as triacylglyceride fragments. Moreover, MS/MS imaging offers a unique possibility for detailed elucidation of biomolecular distribution with high accuracy based on the ion images of its fragments. This is particularly useful in the presence of interferences which disturb the interpretation of biomolecular localization. Graphical abstract MS/MS was performed during time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of Drosophila melongaster (fruit fly) to elucidate the structure and origin of different chemical species in the brain including a range of different phospholipid classes (PC, PI, PE) and di- and triacylglycerides (DAG & TAG) species where reference MS/MS spectra provided a potential means of discriminating between the isobaric [M-OH] + ion of DAGs and the [M-RCO] + ion of TAGs.

  3. Comprehensive analysis of proteins of pH fractionated samples using monolithic LC/MS/MS, intact MW measurement and MALDI-QIT-TOF MS

    PubMed Central

    Yoo, Chul; Patwa, Tasneem H.; Kreunin, Paweena; Miller, Fred R.; Huber, Christian G.; Nesvizhskii, Alexey I.; Lubman, David M.

    2012-01-01

    A comprehensive platform that integrates information from the protein and peptide levels by combining various MS techniques has been employed for the analysis of proteins in fully malignant human breast cancer cells. The cell lysates were subjected to chromatofocusing fractionation, followed by tryptic digestion of pH fractions for on-line monolithic RP-HPLC interfaced with linear ion trap MS analysis for rapid protein identification. This unique approach of direct analysis of pH fractions resulted in the identification of large numbers of proteins from several selected pH fractions, in which approximately 1.5 μg of each of the pH fraction digests was consumed for an analysis time of ca 50 min. In order to combine valuable information retained at the protein level with the protein identifications obtained from the peptide level information, the same pH fraction was analyzed using nonporous (NPS)-RP-HPLC/ESI-TOF MS to obtain intact protein MW measurements. In order to further validate the protein identification procedures from the fraction digest analysis, NPS-RP-HPLC separation was performed for off-line protein collection to closely examine each protein using MALDI-TOF MS and MALDI-quadrupole ion trap (QIT)-TOF MS, and excellent agreement of protein identifications was consistently observed. It was also observed that the comparison to intact MW and other MS information was particularly useful for analyzing proteins whose identifications were suggested by one sequenced peptide from fraction digest analysis. PMID:17206599

  4. Suggestibility and negative priming: two replication studies.

    PubMed

    David, Daniel; Brown, Richard J

    2002-07-01

    Research suggests that inhibiting the effect of irrelevant stimuli on subsequent thought and action (cognitive inhibition) may be an important component of suggestibility. Two small correlation studies were conducted to address the relationship between different aspects of suggestibility and individual differences in cognitive inhibition, operationalized as the degree of negative priming generated by to-be-ignored stimuli in a semantic categorization task. The first study found significant positive correlations between negative priming, hypnotic suggestibility, and creative imagination; a significant negative correlation was obtained between negative priming and interrogative suggestibility, demonstrating the discriminant validity of the study results. The second study replicated the correlation between negative priming and hypnotic suggestibility, using a different suggestibility measurement procedure that assessed subjective experience and hypnotic involuntariness as well as objective responses to suggestions. These studies support the notion that the ability to engage in cognitive inhibition may be an important component of hypnotic responsivity and maybe of other forms of suggestibility.

  5. Validated UPLC/MS/MS assay for quantitative bioanalysis of elbasvir in rat plasma and application to pharmacokinetic study.

    PubMed

    Liu, Haiyan; Xu, Hongjiang; Song, Wei; Zhang, Yinsheng; Yu, Sen; Huang, Xin

    2016-03-15

    Rapid, sensitive, selective and accurate ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of elbasvir (ELB) in rat plasma with deuterated elbasvir (ELB-D6) as internal standard (IS).Sample preparation was done by protein precipitation using acetonitrile containing 50 ng/mL IS. Chromatographic separation was achieved by an UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) column with a gradient mobile phase consisting of acetonitrile-water (containing 5.0mM ammonium acetate with 0.01% acetic acid, pH 4.5) as mobile phase at a flow rate of 0.3 mL/min for 3 min. ELB was monitored using positive electrospray triple quadrupole mass spectrometer (Waters Xevo TQ-S) via multiple reaction monitoring (MRM) mode. The monitored transitions were set at m/z 882.51→656.42 and m/z 888.49→662.43 for ELB and ELB-D6, respectively. The achieved lower limit of quantification was 1.0 ng/mL. The validated method had an excellent linearity in the range of 1.0-2000 ng/mL (r(2)>0.996). Recovery efficiency at three levels QC concentrations of 2.0 (low), 160 (medium) and 1600 (high) ng/mLwas in the range of 98.29-106.40% for ELB. Matrix effect was found to be minimal. The intra- and inter-day precisions were less than 7.01%. The intra- and inter-day accuracies were determined to be within ±6.23% for all accuracy measurements. The validated simple and rapid UPLC-MS/MS method was successfully used to the pharmacokinetics study of ELB in rats, providing its applicability in relevant preclinical studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. The efficacy of cladribine tablets in CIS patients retrospectively assigned the diagnosis of MS using modern criteria: Results from the ORACLE-MS study.

    PubMed

    Freedman, Mark S; Leist, Thomas P; Comi, Giancarlo; Cree, Bruce Ac; Coyle, Patricia K; Hartung, Hans-Peter; Vermersch, Patrick; Damian, Doris; Dangond, Fernando

    2017-01-01

    Multiple sclerosis (MS) diagnostic criteria have changed since the ORACLE-MS study was conducted; 223 of 616 patients (36.2%) would have met the diagnosis of MS vs clinically isolated syndrome (CIS) using the newer criteria. The objective of this paper is to assess the effect of cladribine tablets in patients with a first clinical demyelinating attack fulfilling newer criteria (McDonald 2010) for MS vs CIS. A post hoc analysis for subgroups of patients retrospectively classified as fulfilling or not fulfilling newer criteria at the first clinical demyelinating attack was conducted. Cladribine tablets 3.5 mg/kg ( n  = 68) reduced the risk of next attack or three-month confirmed Expanded Disability Status Scale (EDSS) worsening by 74% vs placebo ( n  = 72); p  = 0.0009 in patients meeting newer criteria for MS at baseline. Cladribine tablets 5.25 mg/kg ( n  = 83) reduced the risk of next attack or three-month confirmed EDSS worsening by 37%, but nominal significance was not reached ( p  = 0.14). In patients who were still CIS after applying newer criteria, cladribine tablets 3.5 mg/kg ( n  = 138) reduced the risk of conversion to clinically definite multiple sclerosis (CDMS) by 63% vs placebo ( n  = 134); p  = 0.0003. Cladribine tablets 5.25 mg/kg ( n  = 121) reduced the risk of conversion by 75% vs placebo ( n  = 134); p  < 0.0001. Regardless of the criteria used to define CIS or MS, 3.5 mg/kg cladribine tablets are effective in patients with a first clinical demyelinating attack. ClinicalTrials.gov registration: The ORACLE-MS study (NCT00725985).

  7. Simultaneous determination of sibutramine and its active metabolites in human plasma by LC-MS/MS and its application to a pharmacokinetic study.

    PubMed

    Bae, Jung-Woo; Choi, Chang-Ik; Jang, Choon-Gon; Lee, Seok-Yong

    2011-11-01

    A simple and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) technique was developed and validated for the determination of sibutramine and its N-desmethyl metabolites (M1 and M2) in human plasma. After extraction with methyl t-butyl ether, chromatographic separation of analytes in human plasma was performed using a reverse-phase Luna C18 column with a mobile phase of acetonitrile-10 mm ammonium formate buffer (50:50, v/v) and quantified by ESI-MS/MS detection in positive ion mode. The flow rate of the mobile phase was 200 μL/min and the retention times of sibutramine, M1, M2 and internal standard (chlorpheniramine) were 1.5, 1.4, 1.3 and 0.9 min, respectively. The calibration curves were linear over the range 0.05-20 ng/mL, for sibutramine, M1 and M2. The lower limit of quantification was 0.05 ng/mL using 500 μL of human plasma. The mean accuracy and the precision in the intra- and inter-day validation for sibutramine, M1 and M2 were acceptable. This LC-MS/MS method showed improved sensitivity and a short run time for the quantification of sibutramine and its two active metabolites in plasma. The validated method was successfully applied to a pharmacokinetic study in human. Copyright © 2011 John Wiley & Sons, Ltd.

  8. Pain responses of Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation: Manchester Pascal Study, MAPASS report 2.

    PubMed

    Muqit, M M K; Marcellino, G R; Gray, J C B; McLauchlan, R; Henson, D B; Young, L B; Patton, N; Charles, S J; Turner, G S; Stanga, P E

    2010-11-01

    To evaluate pain responses following Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation (PRP). Single-centre randomised clinical trial. 40 eyes of 24 patients with treatment-naive proliferative diabetic retinopathy randomised to 20 and 100 ms PRP under topical 0.4% oxybuprocaine. A masked grader used a pain questionnaire within 1 h (numerical pain score (NPS)) and 1 month after treatment (numerical headache score (NHS)). Primary outcome measure was NPS immediately post-PRP. Secondary outcome measures were mean NHS scores and levels of photophobia reported within 4 weeks of primary PRP. Mean laser fluence was significantly lower using 20 ms PRP (4.8 J/cm²) compared to 100 ms PRP (11.8 J/cm²); p < 0.001). Mean NPS scores for treatment were 2.4 (2.3) (mild) for 20 ms PRP group compared to 4.9 (3.3) (moderate) in 100 ms PRP group-a significant difference (95% CI 4.3 to 0.68; p = 0.006). Mean NHS score within 1 month was 1.5 (2.7) in 20 ms PRP group compared to 3.2 (3.5) in the 100 ms PRP group (p < 0.05). The median duration of photophobia after 20 ms PRP was 3 h, and significantly less compared to 100 ms PRP after which 72 h of photophobia was reported (p < 0.001). Multi-spot 20 ms PRP was associated with significantly lower levels of anxiety, headache, pain and photophobia compared to 100 ms single-spot PRP treatment. Possible reasons include lower fluence, shorter-pulse duration, and spatial summation of laser nociception with multi-spot Pascal technique.

  9. Comparative analysis of soybean plasma membrane proteins under osmotic stress using gel-based and LC MS/MS-based proteomics approaches.

    PubMed

    Nouri, Mohammad-Zaman; Komatsu, Setsuko

    2010-05-01

    To study the soybean plasma membrane proteome under osmotic stress, two methods were used: a gel-based and a LC MS/MS-based proteomics method. Two-day-old seedlings were subjected to 10% PEG for 2 days. Plasma membranes were purified from seedlings using a two-phase partitioning method and their purity was verified by measuring ATPase activity. Using the gel-based proteomics, four and eight protein spots were identified as up- and downregulated, respectively, whereas in the nanoLC MS/MS approach, 11 and 75 proteins were identified as up- and downregulated, respectively, under PEG treatment. Out of osmotic stress responsive proteins, most of the transporter proteins and all proteins with high number of transmembrane helices as well as low-abundance proteins could be identified by the LC MS/MS-based method. Three homologues of plasma membrane H(+)-ATPase, which are transporter proteins involved in ion efflux, were upregulated under osmotic stress. Gene expression of this protein was increased after 12 h of stress exposure. Among the identified proteins, seven proteins were mutual in two proteomics techniques, in which calnexin was the highly upregulated protein. Accumulation of calnexin in plasma membrane was confirmed by immunoblot analysis. These results suggest that under hyperosmotic conditions, calnexin accumulates in the plasma membrane and ion efflux accelerates by upregulation of plasma membrane H(+)-ATPase protein.

  10. Co-morbidities increase the risk of disability pension among MS patients: a population-based nationwide cohort study.

    PubMed

    Tinghög, Petter; Björkenstam, Charlotte; Carstensen, John; Jansson, Catarina; Glaser, Anna; Hillert, Jan; Alexanderson, Kristina

    2014-06-03

    Multiple sclerosis (MS) is a chronic and often disabling disease. In 2005, 62% of the MS patients in Sweden aged 16-65 years were on disability pension. The objective of this study is to investigate whether the presence of common co-morbidities increase MS patients' risk for disability pension. This population-based cohort study included 4 519 MS patients and 4 972 174 non-MS patients who in 2005 were aged 17-64 years, lived in Sweden, and were not on disability pension. Patients with MS were identified in the nationwide in- and outpatient registers, while four different registers were used to construct three sets of measures of musculoskeletal, mental, and cardiovascular disorders. Time-dependent proportional hazard models with a five-year follow up were performed, adjusting for socio-demographic factors. All studied disorders were elevated among MS patients, regardless of type of measure used. MS patients with mental disorders had a higher risk for disability pension than MS patients with no such co-morbidities. Moreover, mental disorders had a synergistic influence on MS patients' risk for disability pension. These findings were also confirmed when conducting sensitivity analyses. Musculoskeletal disorders appeared to increase MS patients' risk for disability pension. The results with regard to musculoskeletal disorders' synergistic influence on disability pension were however inconclusive. Cardiovascular co-morbidity had no significant influence on MS-patients' risk for disability pension. Co-morbidities, especially mental disorders, significantly contribute to MS patients' risk of disability pension, a finding of relevance for MS management and treatment.

  11. Analysis of Carbamate Pesticides: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS666

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Owens, J; Koester, C

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method for analysis of aldicarb, bromadiolone, carbofuran, oxamyl, and methomyl in water by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), titled Method EPA MS666. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in MS666 for analysis of carbamatemore » pesticides in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of Method EPA MS666 can be determined.« less

  12. Natalizumab Discontinuation and Treatment Strategies in Patients with Multiple Sclerosis (MS): A Retrospective Study from Two Italian MS Centers.

    PubMed

    Lo Re, Marianna; Capobianco, Marco; Ragonese, Paolo; Realmuto, Sabrina; Malucchi, Simona; Berchialla, Paola; Salemi, Giuseppe; Bertolotto, Antonio

    2015-12-01

    Natalizumab (NTZ) discontinuation can be followed by multiple sclerosis (MS) disease reactivation. Currently no disease-modifying drug (DMD) has been shown to be able to abolish disease reactivation. The aims of the current study were: (1) to determine the frequency of MS reactivation after NTZ discontinuation; (2) to evaluate predictors of reactivation risk, and (3) to compare the effect of different treatments in reducing this risk. Data from 132 patients with MS followed-up for 2 years before NTZ treatment and 1 year after interruption were collected from two Italian MS centers and retrospectively evaluated. Overall, 72 of 132 patients (54.5%) had relapses after NTZ discontinuation and 60 of 125 patients (48%), who had magnetic resonance imaging, had radiological reactivation. Rebound was observed in 28 of 132 patients (21.2%). A higher number of relapses in the 2 years before NTZ treatment, a longer washout period, and a lower number NTZ infusions correlated with reactivation and rebound. Untreated patients (n = 37) had higher clinical and radiological activity and rebound in comparison to patients receiving DMDs. Moreover, a lower risk of relapses was found in patients treated with second-line therapies (NTZ and fingolimod) than in those treated with first-line therapies (interferon beta, glatiramer acetate, teriflunomide, azathioprine). Interestingly, no disease reactivation in off-label treatment (rituximab, autologous hematopoietic stem cell transplantation) was observed. NTZ discontinuation is a risk for MS reactivation and rebound. An alternative treatment should be promptly resumed mainly in patients with a previous very active disease course and with a shorter NTZ therapy. Second-line therapies demonstrate superiority in preventing relapses after NTZ discontinuation.

  13. Tissue Localization of Glycosphingolipid Accumulation in a Gaucher Disease Mouse Brain by LC-ESI-MS/MS and High-Resolution MALDI Imaging Mass Spectrometry.

    PubMed

    Jones, E Ellen; Zhang, Wujuan; Zhao, Xueheng; Quiason, Cristine; Dale, Stephanie; Shahidi-Latham, Sheerin; Grabowski, Gregory A; Setchell, Kenneth D R; Drake, Richard R; Sun, Ying

    2017-12-01

    To better understand regional brain glycosphingolipid (GSL) accumulation in Gaucher disease (GD) and its relationship to neuropathology, a feasibility study using mass spectrometry and immunohistochemistry was conducted using brains derived from a GD mouse model (4L/PS/NA) homozygous for a mutant GCase (V394L [4L]) and expressing a prosaposin hypomorphic (PS-NA) transgene. Whole brains from GD and control animals were collected using one hemisphere for MALDI FTICR IMS analysis and the other for quantitation by LC-ESI-MS/MS. MALDI IMS detected several HexCers across the brains. Comparison with the brain hematoxylin and eosin (H&E) revealed differential signal distributions in the midbrain, brain stem, and CB of the GD brain versus the control. Quantitation of serial brain sections with LC-ESI-MS/MS supported the imaging results, finding the overall HexCer levels in the 4L/PS-NA brains to be four times higher than the control. LC-ESI-MS/MS also confirmed that the elevated hexosyl isomers were glucosylceramides rather than galactosylceramides. MALDI imaging also detected differential analyte distributions of lactosylceramide species and gangliosides in the 4L/PS-NA brain, which was validated by LC-ESI-MS/MS. Immunohistochemistry revealed regional inflammation, altered autophagy, and defective protein degradation correlating with regions of GSL accumulation, suggesting that specific GSLs may have distinct neuropathological effects.

  14. LC-MS and MS/MS in the analysis of recombinant proteins

    NASA Astrophysics Data System (ADS)

    Coulot, M.; Domon, B.; Grossenbacher, H.; Guenat, C.; Maerki, W.; Müller, D. R.; Richter, W. J.

    1993-03-01

    Applicability and performance of electrospray ionization mass spectrometry (ESIMS) is demonstrated for protein analysis. ESIMS is applied in conjunction with on-line HPLC (LC-ESlMS) and direct tandem mass spectrometry (positive and negative ion mode ESlMS/MS) to the structural characterization of a recombinant protein (r-hirudin variant 1) and a congener phosphorylated at threonine 45 (RP-1).

  15. Improving fatigue in multiple sclerosis by smartphone-supported energy management: The MS TeleCoach feasibility study.

    PubMed

    D'hooghe, Marie; Van Gassen, Geert; Kos, Daphne; Bouquiaux, Olivier; Cambron, Melissa; Decoo, Danny; Lysandropoulos, Andreas; Van Wijmeersch, Bart; Willekens, Barbara; Penner, Iris-Katharina; Nagels, Guy

    2018-03-27

    Fatigue is a frequently occurring, often disabling symptom in MS with no single effective treatment. In current fatigue management interventions, personalized, real-time follow-up is often lacking. The objective of the study is to assess the feasibility of the MS TeleCoach, a novel intervention offering telemonitoring of fatigue and telecoaching of physical activity and energy management in persons with MS (pwMS) over a 12-week period. The goal of the MS TeleCoach, conceived as a combination of monitoring, self-management and motivational messages, is to enhance levels of physical activity thereby improving fatigue in pwMS in an accessible and interactive way, reinforcing self-management of patients. We conducted a prospective, open-label feasibility study of the MS TeleCoach in pwMS with Expanded Disability Status Scale ≤ 4 and moderate to severe fatigue as measured by the Fatigue Scale for Motor and Cognitive Functions (FSMC). Following a 2-week run-in period to assess the baseline activity level per patient, the target number of activity counts was gradually increased over the 12-week period through telecoaching. The primary efficacy outcome was change in FSMC total score from baseline to study end. A subset of patients was asked to fill in D-QUEST 2.0, a usability questionnaire, to evaluate the satisfaction with the MS TeleCoach device and the experienced service. Seventy-five patients were recruited from 16 centres in Belgium, of which 57 patients (76%) completed the study. FSMC total score (p = 0.009) and motor and cognitive subscores (p = 0.007 and p = 0.02 respectively) decreased from baseline to week 12, indicating an improvement in fatigue. One third of participants with severe fatigue changed to a lower FSMC category for both FSMC total score and subscores. The post-study evaluation of patient satisfaction showed that the intervention was well accepted and that patients were very satisfied with the quality of the professional services

  16. General Unknown Screening by Ion Trap LC/MS/MS

    DTIC Science & Technology

    2010-04-01

    Subtitle 5 . Report Date April 2010 General Unknown Screening by Ion Trap LC/MS/MS 6 . Performing Organization Code 7. Author(s) 8... 5 Table 1: Analytical Data for Each of the...359 Compounds in the LC/MS/MS Library . . . . . . . . . . . 6 1 General Unknown ScreeninG by ion Trap lc/MS/MS INTrOduCTION The Federal Aviation

  17. Determination and pharmacokinetic study of pirfenidone in rat plasma by UPLC-MS/MS.

    PubMed

    Sun, Wei; Jiang, Zhe-li; Zhou, Lei; Chen, Rui-min; Wang, Zhe; Li, Wan-shu; Jiang, Shuo-min; Hu, Guo-xin; Chen, Rui-jie

    2015-02-15

    A rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of pirfenidone in rat plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2 mL of acetonitrile to a 0.1 mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 3.0 min and the elution of pirfenidone was at 1.39 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 186.2→92.1 for pirfenidone and m/z 237.1→194.2 for carbamazepine (IS), respectively. The calibration curve was linear over the range of 5-2000 ng/mL with a lower limit of quantitation (LLOQ) of 5 ng/mL. Mean recovery of pirfenidone in plasma was in the range of 80.4-84.3%. Intra-day and inter-day precision were both <12.1%. This method was successfully applied in pharmacokinetic study after oral administration of 10.0mg/kg pirfenidone in rats. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. High throughput LC-MS/MS method for the simultaneous analysis of multiple vitamin D analytes in serum.

    PubMed

    Jenkinson, Carl; Taylor, Angela E; Hassan-Smith, Zaki K; Adams, John S; Stewart, Paul M; Hewison, Martin; Keevil, Brian G

    2016-03-01

    Recent studies suggest that vitamin D-deficiency is linked to increased risk of common human health problems. To define vitamin D 'status' most routine analytical methods quantify one particular vitamin D metabolite, 25-hydroxyvitamin D3 (25OHD3). However, vitamin D is characterized by complex metabolic pathways, and simultaneous measurement of multiple vitamin D metabolites may provide a more accurate interpretation of vitamin D status. To address this we developed a high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to analyse multiple vitamin D analytes, with particular emphasis on the separation of epimer metabolites. A supportive liquid-liquid extraction (SLE) and LC-MS/MS method was developed to quantify 10 vitamin D metabolites as well as separation of an interfering 7α-hydroxy-4-cholesten-3-one (7αC4) isobar (precursor of bile acid), and validated by analysis of human serum samples. In a cohort of 116 healthy subjects, circulating concentrations of 25-hydroxyvitamin D3 (25OHD3), 3-epi-25-hydroxyvitamin D3 (3-epi-25OHD3), 24,25-dihydroxyvitamin D3 (24R,25(OH)2D3), 1,25-dihydroxyvitamin D3 (1α,25(OH)2D3), and 25-hydroxyvitamin D2 (25OHD2) were quantifiable using 220μL of serum, with 25OHD3 and 24R,25(OH)2D3 showing significant seasonal variations. This high-throughput LC-MS/MS method provides a novel strategy for assessing the impact of vitamin D on human health and disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Therapeutic drug monitoring of tamoxifen using LC-MS/MS.

    PubMed

    Tchu, Simone M; Lynch, Kara L; Wu, Alan H B

    2012-01-01

    Tamoxifen is a selective estrogen receptor modulator (SERM) that is used widely in the treatment of estrogen receptor positive breast cancer (ER+). Therapeutic monitoring of tamoxifen, and its metabolites N-desmethyltamoxifen (NDTam) and 4-hydroxy-N-desmethyltamoxifen (endoxifen), may be clinically useful for guiding treatment decisions. Two significant barriers to tamoxifen efficacy are: (1) variability in conversion of tamoxifen into the potent antiestrogenic metabolite, endoxifen, and (2) poor compliance and adherence to tamoxifen therapy. Therapeutic monitoring can be used to address both of these issues. Low levels of endoxifen indicate either poor compliance or poor metabolism of tamoxifen. Low tamoxifen levels would suggest poor compliance while a low ratio of endoxifen to NDTam would be indicative of poor metabolism. Solid phase extraction of patient serum followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) detection enables rapid, accurate, detection of tamoxifen, N-desmethyltamoxifen, and endoxifen.

  20. On the Ionization and Ion Transmission Efficiencies of Different ESI-MS Interfaces

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cox, Jonathan T.; Marginean, Ioan; Smith, Richard D.

    2014-09-30

    It is well known that the achievable sensitivity of electrospray ionization mass spectrometry (ESI-MS) is largely determined by the ionization efficiency in the ESI source and ion transmission efficiency through the ESI-MS interface. In this report we systematically study the ion transmission and ionization efficiencies in different ESI-MS interface configurations. The configurations under investigation include a single emitter/single inlet capillary, single emitter/multi-inlet capillary, and a subambient pressure ionization with nanoelectrospray (SPIN) MS interfaces with a single emitter and an emitter array, respectively. We present an effective method to evaluate the overall ion utilization efficiency of an ESI-MS interface by measuringmore » the total gas phase ion current transmitted through the interface and correlating it to the observed ion abundance measured in the corresponding mass spectrum. Our experimental results suggest that the overall ion utilization efficiency in the SPIN-MS interface configurations is better than that in the inlet capillary based ESI-MS interface configurations.« less

  1. The potential of combining ion trap/MS/MS and TOF/MS for identification of emerging contaminants

    USGS Publications Warehouse

    Ferrer, I.; Furlong, E.T.; Heine, C.E.; Thurman, E.M.

    2002-01-01

    The use of a method combining ion trap tandem mass spectrometry (MS/MS) and time of flight mass spectrometry (TOF/MS) for identification of emerging contaminates was discussed. The two tools together complemented each other in sensitivity, fragmentation and accurate mass determination. Liquid chromatography/electrospray ionization/ion-trap tandem mass spectrometry (LC/ESI/MS/MS), in positive ion mode of operation, was used to separate and identify specific compounds. Diagnostic fragment ions were obtained for a polyethyleneglycol(PEG) homolog by ion trap MS/MS, and fragments were measured by TOF/MS. It was observed that the combined method gave an exact mass measurement that differed from the calculated mass.

  2. Analysis of pesticide residues in strawberries and soils by GC-MS/MS, LC-MS/MS and two-dimensional GC-time-of-flight MS comparing organic and integrated pest management farming.

    PubMed

    Fernandes, Virgínia C; Lehotay, Steven J; Geis-Asteggiante, Lucía; Kwon, Hyeyoung; Mol, Hans G J; van der Kamp, Henk; Mateus, Nuno; Domingues, Valentina F; Delerue-Matos, Cristina

    2014-01-01

    This study analysed 22 strawberry and soil samples after their collection over the course of 2 years to compare the residue profiles from organic farming with integrated pest management practices in Portugal. For sample preparation, we used the citrate-buffered version of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. We applied three different methods for analysis: (1) 27 pesticides were targeted using LC-MS/MS; (2) 143 were targeted using low pressure GC-tandem mass spectrometry (LP-GC-MS/MS); and (3) more than 600 pesticides were screened in a targeted and untargeted approach using comprehensive, two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS). Comparison was made of the analyses using the different methods for the shared samples. The results were similar, thereby providing satisfactory confirmation of both similarly positive and negative findings. No pesticides were found in the organic-farmed samples. In samples from integrated pest management practices, nine pesticides were determined and confirmed to be present, ranging from 2 µg kg(-1) for fluazifop-p-butyl to 50 µg kg(-1) for fenpropathrin. Concentrations of residues in strawberries were less than European maximum residue limits.

  3. Screening Antioxidants Using LC-MS: A Case Study with Cocoa

    PubMed Central

    Calderón, Angela I.; Wright, Brian J.; Hurst, W. Jeffrey; van Breemen, Richard B.

    2009-01-01

    Oxidative stress enhances pathological processes contributing to cancer, cardiovascular disease and neurodegenerative diseases, and dietary antioxidants may counteract these deleterious processes. Since rapid methods to evaluate and compare food products for antioxidant benefits are needed, a new assay based on liquid chromatography-mass spectrometry (LC-MS) was developed for the identification and quantitative analysis of antioxidants in complex natural product samples such as food extracts. This assay is based on the comparison of electrospray LC-MS profiles of sample extracts before and after treatment with reactive oxygen species such as hydrogen peroxide or DPPH (2,2-diphenyl-1-picrylhydrazyl radical). Using this assay, methanolic extracts of cocoa powder were analyzed, and procyanidins were found to be the most potent antioxidant species. These species were identified using LC-MS, LC-MS-MS, accurate mass measurement, and comparison with reference standards. Furthermore, LC-MS was used to determine the levels of these species in cocoa samples. Catechin and epicatechin were the most abundant antioxidants followed by their dimers and trimers. The most potent antioxidants in cocoa were trimers and dimers of catechin and epicatechin, such as procyanidin B2, followed by catechin and epicatechin. This new LC-MS assay facilitates the rapid identification and then the determination of the relative antioxidant activities of individual antioxidant species in complex natural product samples and food products such as cocoa. PMID:19489609

  4. Low Mass MS/MS Fragments of Protonated Amino Acids Used for Distinction of Their 13C- Isotopomers in Metabolic Studies

    NASA Astrophysics Data System (ADS)

    Ma, Xin; Dagan, Shai; Somogyi, Árpád; Wysocki, Vicki H.; Scaraffia, Patricia Y.

    2013-04-01

    Glu, Gln, Pro, and Ala are the main amino acids involved in ammonia detoxification in mosquitoes. In order to develop a tandem mass spectrometry method (MS2) to monitor each carbon of the above isotopically-labeled 13C-amino acids for metabolic studies, the compositions and origins of atoms in fragments of the protonated amino acid should be first elucidated. Thus, various electrospray (ESI)-based MS2 tools were employed to study the fragmentation of these unlabeled and isotopically-labeled amino acids and better understand their dissociation pathways. A broad range of fragments, including previously-undescribed low m/z fragments was revealed. The formulae of the fragments (from m/z 130 down to m/z 27) were confirmed by their accurate masses. The structures and conformations of the larger fragments of Glu were also explored by ion mobility mass spectrometry (IM-MS) and gas-phase hydrogen/deuterium exchange (HDX) experiments. It was found that some low m/z fragments ( m/z 27-30) are common to Glu, Gln, Pro, and Ala. The origins of carbons in these small fragments are discussed and additional collision induced dissociation (CID) MS2 fragmentation pathways are proposed for them. It was also found that small fragments (≤ m/z 84) of protonated, methylated Glu, and methylated Gln are the same as those of the underivatized Glu and Gln. Taken together, the new approach of utilizing low m/z fragments can be applied to distinguish, identify, and quantify 13C-amino acids labeled at various positions, either in the backbone or side chain.

  5. MS Based Metabonomics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Want, Elizabeth J.; Metz, Thomas O.

    in Figure 1. Gas chromatography-(GC)-MS was the most commonly used MS-based method for small molecule analysis in the 1970s and 1980s. It is still used today for the detection of many metabolic disorders and plays a strong role in plant metabonomics. Liquid chromatography (LC)-MS approaches have grown in popularity for metabolite studies, due to simpler sample preparation, reduced analysis times through the introduction of ultra-high performance liquid chromatography (UPLC)-MS and the ability to observe a wider range of metabolites. This chapter will discuss the role of MS in metabonomics, the techniques involved in this exciting area, and the current and future applications of the field. The various bioinformatics tools and multivariate analysis techniques used to maximize information recovery and to aid in the interpretation of the very large data sets typically obtained in metabonomics studies will also be discussed. While there are many different MS-based approaches utilized in metabonomics studies, emphasis will be placed on more established methods.« less

  6. Radioimmunoassay of CSF for encephalitogenic basic protein: a diagnostic test for MS?

    PubMed Central

    McPherson, T. A.; Gilpin, Annabel; Seland, T. P.

    1972-01-01

    Competitive inhibition of binding between radioiodine-labelled encephalitogenic basic protein from human myelin (125I-HEProt) and normal human alpha-2 macroglobulin and between 125I-HEProt and rabbit antiHEProt serum was used to study concentrated cerebrospinal fluid (CSF) under “blind” control for cross-reactivity with HEProt. Samples of CSF from patients meeting the standard criteria for definite MS and possible MS, and from patients with optic neuritis and “other” diagnoses were studied. CSF from patients in all four groups was shown to have an inhibitor cross-reactive with HEProt when studied by the 125I-HEProt/alpha-2 macroglobulin test, but the amount was significantly greater in the definite MS group than in the “other” group. Results of the two tests on CSF from MS patients correlated, suggesting that the tests were identifying the same inhibitor. It was concluded that CSF contains an inhibitor similar to HEProt and that the amount present in CSF could be a useful diagnostic marker of MS. PMID:4120149

  7. Comparison of serum serotonin and serum 5-HIAA LC-MS/MS assays in the diagnosis of serotonin producing neuroendocrine neoplasms: A pilot study.

    PubMed

    Lindström, Mikael; Tohmola, Niina; Renkonen, Risto; Hämäläinen, Esa; Schalin-Jäntti, Camilla; Itkonen, Outi

    2018-07-01

    Serotonin (5-hydroxytyramine) is a mediator of gastrointestinal smooth muscle contraction, and is secreted by neuroendocrine neoplasms (NENs). We developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for serum serotonin to be used in NEN diagnostics and follow-up. We used serum samples from healthy volunteers (n = 31) and patients suspected or monitored for NEN (n = 98). Serotonin-D 4 internal standard was added to samples before solid phase extraction (SPE) and quantification by LC-MS/MS. The effects of sample handling and preparation on serotonin stability were studied. Finally, we established a provisional reference range for serum serotonin and compared our assay with serum 5-hydroxyindoleacetic acid (5-HIAA) for detection of NENs. Our assay is sensitive and has a wide linear range (10-10,000 nmol/l). Serum serotonin is stable for 7 days at room temperature and for 3 months at -20 °C. Sampling temperature is not critical. Normal range for serum serotonin was 270-1490 nmol/l. We found that serum serotonin and 5-HIAA performed equally well as diagnostic tests for NENs. Our LC-MS/MS assay for serum serotonin is well suited for clinical research and patient diagnostics. Our results confirm that it can complement 5-HIAA in diagnosis of NENs. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Study of sample preparation for determination of endocannabinoids and analogous compounds in human serum by LC-MS/MS in MRM mode.

    PubMed

    Luque-Córdoba, D; Calderón-Santiago, M; Luque de Castro, M D; Priego-Capote, F

    2018-08-01

    Endocannabinoids are lipids with a key role in physiological processes such as the immune response or the metabolism. This involvement explains their association to pathologies such as cancer, obesity or multiple sclerosis. The determination of endocannabinoids constitutes a challenge for clinical laboratories due to the variety of biological matrices and the wide range of concentrations at which they can be found. This research deals with the comparison of three sample preparation strategies (viz., on-line SPE, off-line SPE for interferents removal, and protein precipitation) for subsequent LC-MS/MS analysis of 14 endocannabinoids and analogous compounds in serum. As a result, the on-line coupling between SPE and LC-MS/MS is proposed as the best approach for this determination. The proposed method allows full automation of the overall process, shortening of the analysis time, and avoidance of errors associated with sample preparation steps. The improvement in sensitivity and selectivity thus achieved allows obtaining quantification limits at the pg mL -1 level, which makes possible the application of the method for clinical studies. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Analysis of oxcarbazepine and the 10-hydroxycarbazepine enantiomers in plasma by LC-MS/MS: application in a pharmacokinetic study.

    PubMed

    de Jesus Antunes, Natalicia; Wichert-Ana, Lauro; Coelho, Eduardo Barbosa; Della Pasqua, Oscar; Alexandre, Veriano; Takayanagui, Osvaldo Massaiti; Tozatto, Eduardo; Lanchote, Vera Lucia

    2013-12-01

    Oxcarbazepine is a second-generation antiepileptic drug indicated as monotherapy or adjunctive therapy in the treatment of partial seizures or generalized tonic-clonic seizures in adults and children. It undergoes rapid presystemic reduction with formation of the active metabolite 10-hydroxycarbazepine (MHD), which has a chiral center at position 10, with the enantiomers (S)-(+)- and R-(-)-MHD showing similar antiepileptic effects. This study presents the development and validation of a method of sequential analysis of oxcarbazepine and MHD enantiomers in plasma using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Aliquots of 100 μL of plasma were extracted with a mixture of methyl tert-butyl ether: dichloromethane (2:1). The separation of oxcarbazepine and the MHD enantiomers was obtained on a chiral phase Chiralcel OD-H column, using a mixture of hexane:ethanol:isopropanol (80:15:5, v/v/v) as mobile phase at a flow rate of 1.3 mL/min with a split ratio of 1:5, and quantification was performed by LC-MS/MS. The limit of quantification was 12.5 ng oxcarbazepine and 31.25 ng of each MHD enantiomer/mL of plasma. The method was applied in the study of kinetic disposition of oxcarbazepine and the MHD enantiomers in the steady state after oral administration of 300 mg/12 h oxcarbazepine in a healthy volunteer. The maximum plasma concentration of oxcarbazepine was 1.2 µg/mL at 0.75 h. The kinetic disposition of MHD is enantioselective, with a higher proportion of the S-(+)-MHD enantiomer compared to R-(-)-MHD and an AUC(0-12) S-(+)/R-(-) ratio of 5.44. © 2013 Wiley Periodicals, Inc.

  10. Study on Chemical Constituents in Polygoni Cuspidati Folium and its Preparation by UPLC-ESI-Q-TOF-MS/MS.

    PubMed

    Wang, Xin; Qin, Yao; Li, Guang-Quan; Chen, Shuai; Ma, Jing-Qi; Guo, Yan-Lei; Luo, Wei-Zao

    2018-03-15

    A rapid and credible analytical method was developed using online UPLC-ESI-Q-TOF-MS/MS to identify chemical constituents in Polygoni cuspidati folium and its preparation. By accurate mass measurements within 6.5 ppm error for [M-H]- ion in routine analysis, 26 chemical constituents, including tannin, derivatives of phenylpropionic acid, stilbene, flavonoid, anthraquinone, torachryson and its derivatives, were identified or tentatively characterized. Among them, five constituents (compounds 19-23) were firstly reported in Polygoni cuspidati folium, other 17 constituents were coexisting in both Polygoni cuspidati folium and its preparation. Fragmentation behaviors of different categories of constituents were also investigated to confirm the results. This established UPLC-ESI-Q-TOF-MS/MS method, with reliance and efficiency for the identification the major constituents, would be the basis for quality control of Polygoni cuspidati folium and its preparation.

  11. Simultaneous quantitation of hydroxychloroquine and its metabolites in mouse blood and tissues using LC-ESI-MS/MS: An application for pharmacokinetic studies.

    PubMed

    Chhonker, Yashpal S; Sleightholm, Richard L; Li, Jing; Oupický, David; Murry, Daryl J

    2018-01-01

    Hydroxychloroquine (HCQ) has been shown to disrupt autophagy and sensitize cancer cells to radiation and chemotherapeutic agents. However, the optimal delivery method, dose, and tumor concentrations required for these effects are not known. This is in part due to a lack of sensitive and reproducible analytical methods for HCQ quantitation in small animals. As such, we developed and validated a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method for simultaneous quantitation of hydroxychloroquine and its metabolites in mouse blood and tissues. The chromatographic separation and detection of analytes were achieved on a reversed phase Thermo Aquasil C 18 (50×4.6mm, 3μ) column, with gradient elution using 0.2% formic acid and 0.1% formic acid in methanol as mobile phase at a flow rate of 0.5mL/min. Simple protein precipitation was utilized for extraction of analytes from the desired matrix. Analytes were separated and quantitated using MS/MS with an electrospray ionization source in positive multiple reaction monitoring (MRM) mode. The MS/MS response was linear over the concentration range from 1 to 2000ng/mL for all analytes with a correlation coefficient (R 2 ) of 0.998 or better. The within- and between-day precision (relative standard deviation, % RSD) and accuracy were within the acceptable limits per FDA guidelines. The validated method was successfully applied to a preclinical pharmacokinetic mouse study involving low volume blood and tissue samples for hydroxychloroquine and metabolites. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Efficient approach for the detection and identification of new androgenic metabolites by applying SRM GC-CI-MS/MS: a methandienone case study.

    PubMed

    Polet, Michael; Van Gansbeke, Wim; Van Eenoo, Peter; Deventer, Koen

    2016-07-01

    Identification of anabolic androgenic steroids (AAS) is a vital issue in doping control and toxicology, and searching for metabolites with longer detection times remains an important task. Recently, a gas chromatography chemical ionization triple quadrupole mass spectrometry (GC-CI-MS/MS) method was introduced, and CI, in comparison with electron ionization (EI), proved to be capable of increasing the sensitivity significantly. In addition, correlations between AAS structure and fragmentation behavior could be revealed. This enables the search for previously unknown but expected metabolites by selection of their predicted transitions. The combination of both factors allows the setup of an efficient approach to search for new metabolites. The approach uses selected reaction monitoring which is inherently more sensitive than full scan or precursor ion scan. Additionally, structural information obtained from the structure specific CI fragmentation pattern facilitates metabolite identification. The procedure was demonstrated by a methandienone case study. Its metabolites have been studied extensively in the past, and this allowed an adequate evaluation of the efficiency of the approach. Thirty three metabolites were detected, including all relevant previously discovered metabolites. In our study, the previously reported long-term metabolite (18-nor-17β-hydroxymethyl,17α-methyl-androst-1,4,13-trien-3-one) could be detected up to 26 days by using GC-CI-MS/MS. The study proves the validity of the approach to search for metabolites of new synthetic AAS and new long-term metabolites of less studied AAS and illustrates the increase in sensitivity by using CI. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  13. DBS-LC-MS/MS assay for caffeine: validation and neonatal application.

    PubMed

    Bruschettini, Matteo; Barco, Sebastiano; Romantsik, Olga; Risso, Francesco; Gennai, Iulian; Chinea, Benito; Ramenghi, Luca A; Tripodi, Gino; Cangemi, Giuliana

    2016-09-01

    DBS might be an appropriate microsampling technique for therapeutic drug monitoring of caffeine in infants. Nevertheless, its application presents several issues that still limit its use. This paper describes a validated DBS-LC-MS/MS method for caffeine. The results of the method validation showed an hematocrit dependence. In the analysis of 96 paired plasma and DBS clinical samples, caffeine levels measured in DBS were statistically significantly lower than in plasma but the observed differences were independent from hematocrit. These results clearly showed the need for extensive validation with real-life samples for DBS-based methods. DBS-LC-MS/MS can be considered to be a good alternative to traditional methods for therapeutic drug monitoring or PK studies in preterm infants.

  14. Kinetics of plasma apolipoprotein E isoforms by LC-MS/MS: a pilot study.

    PubMed

    Blanchard, Valentin; Ramin-Mangata, Stéphane; Billon-Crossouard, Stéphanie; Aguesse, Audrey; Durand, Manon; Chemello, Kevin; Nativel, Brice; Flet, Laurent; Chétiveaux, Maud; Jacobi, David; Bard, Jean-Marie; Ouguerram, Khadija; Lambert, Gilles; Krempf, Michel; Croyal, Mikaël

    2018-05-01

    Human apoE exhibits three major isoforms (apoE2, apoE3, and apoE4) corresponding to polymorphism in the APOE gene. Total plasma apoE concentrations are closely related to these isoforms, but the underlying mechanisms are unknown. We aimed to describe the kinetics of apoE individual isoforms to explore the mechanisms for variable total apoE plasma concentrations. We used LC-MS/MS to discriminate between isoforms by identifying specific peptide sequences in subjects (three E2/E3, three E3/E3, and three E3/E4 phenotypes) who received a primed constant infusion of 2 H 3 -leucine for 14 h. apoE concentrations and leucine enrichments were measured hourly in plasma. Concentrations of apoE2 were higher than apoE3, and concentrations of apoE4 were lower than apoE3. There was no difference between apoE3 and apoE4 catabolic rates and between apoE2 and apoE3 production rates (PRs), but apoE2 catabolic rates and apoE4 PRs were lower. The mechanisms leading to the difference in total plasma apoE concentrations are therefore related to contrasted kinetics of the isoforms. Production or catabolic rates are differently affected according to the specific isoforms. On these grounds, studies on the regulation of the involved biochemical pathways and the impact of pathological environments are now warranted. Copyright © 2018 Blanchard et al.

  15. Comparing depression screening tools in persons with multiple sclerosis (MS).

    PubMed

    Hanna, Joshua; Santo, Jonathan B; Blair, Mervin; Smolewska, Kathy; Warriner, Erin; Morrow, Sarah A

    2017-02-01

    Depression is more common among persons with multiple sclerosis (MS) than the general population. Depression in MS is associated with reduced quality of life, transition to unemployment, and cognitive impairment. Two proposed screening measures for depression in MS populations are the Hospital Anxiety and Depression Scale (HADS) and the Beck Depression Inventory-Fast Screen (BDI-FS). Our objective was to compared the associations of the BDI-FS and the HADS-D scores with history of depressive symptoms, fatigue, and functional outcomes to determine the differential clinical utility of these screening measures among persons with MS. We reviewed charts of 133 persons with MS for demographic information; scores on the HADS, BDI-FS, a fatigue measure, and a processing speed measure; and employment status. Structural equation modeling results indicated the HADS-D predicted employment status, disability status, and processing speed more effectively than did the BDI-FS, whereas both measures predicted fatigue. This study suggests the HADS-D is more effective than the BDI-FS in predicting functional outcomes known to be associated with depression among persons with MS. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Chromatographic separation of piracetam and its metabolite in a mixture of microsomal preparations, followed by an MS/MS analysis.

    PubMed

    Sahu, Kapendra; Siddiqui, Anees A; Shaharyar, Mohammad; Ahmad, Niyaz; Anwar, Mohammad; Ahmad, Farhan J

    2013-07-01

    A rapid bioanalytical method was evaluated for the simultaneous determination of piracetam and its metabolite (M1) in human microsomal preparations by fast ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). In addition, a validated method of M1 in rat plasma was developed and successfully applied on pharmacokinetic studies. The present study was carried out to determine the metabolic pathways of piracetam for phase I metabolism and used cytochrome P450 isoforms responsible for the piracetam metabolism in human liver microsomes (HLMs). While additional potential metabolites of piracetam were suggested by computer-modeling. The resulting 2-(2-oxopyrrolidin-1-yl) acetic acid was the sole metabolite detected after the microsomal treatment. The amide hydrolysis mainly underwent to form a metabolite i.e., 2-(2-oxopyrrolidin-1-yl) acetic acid (M1). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  17. HPLC and HPLC/MS/MS Studies on Stress, Accelerated and Intermediate Degradation Tests of Antivirally Active Tricyclic Analog of Acyclovir.

    PubMed

    Lesniewska, Monika A; Dereziński, Paweł; Klupczyńska, Agnieszka; Kokot, Zenon J; Ostrowski, Tomasz; Zeidler, Joanna; Muszalska, Izabela

    2015-01-01

    The degradation behavior of a tricyclic analog of acyclovir [6-(4-MeOPh)-TACV] was determined in accordance with International Conference on Harmonization guidelines for good clinical practice under different stress conditions (neutral hydrolysis, strong acid/base degradation, oxidative decomposition, photodegradation, and thermal degradation). Accelerated [40±2°C/75%±5% relative humidity (RH)] and intermediate (30±2°C/65%±5% RH) stability tests were also performed. For observation of the degradation of the tested compound the RP-HPLC was used, whereas for the analysis of its degradation products HPLC/MS/MS was used. Degradation of the tested substance allowed its classification as unstable in neutral environment, acidic/alkaline medium, and in the presence of oxidizing agent. The tested compound was also light sensitive and was classified as photolabile both in solution and in the solid phase. However, the observed photodegradation in the solid phase was at a much lower level than in the case of photodegradation in solution. The study showed that both air temperature and RH had no significant effect on the stability of the tested substance during storage for 1 month at 100°C (dry heat) as well as during accelerated and intermediate tests. Based on the HPLC/MS/MS analysis, it can be concluded that acyclovir was formed as a degradation product of 6-(4-MeOPh)-TACV.

  18. Quantification of amlodipine and atorvastatin in human plasma by UPLC-MS/MS method and its application to a bioequivalence study.

    PubMed

    Rezk, Mamdouh R; Badr, Kamal A

    2018-07-01

    A robust, rapid and sensitive UPLC-MS/MS method has been developed, optimized and validated for the determination of amlodipine (AML) and atorvastatin (ATO) in human plasma using eplerenone as an internal standard (IS). Multiple-reaction monitoring in positive electrospray ionization mode was utilized in Xevo TQD LC-MS/MS. Double extraction was used in sample preparation using diethyl ether and ethyl acetate. The prepared samples were analyzed using an Acquity UPLC BEH C 18 (50 × 2.1 mm, 1.7 μm) column. Ammonium formate and acetonitrile, pumped isocraticaly at a flow rate of 0.25 mL/min, were used as a mobile phase. Method validation was done as per the US Food and Drug Administration guidelines. Linearity was achieved in the range of 0.1-10 ng/mL for AML and 0.05-50 ng/mL for ATO. Intra-day and inter-day accuracy and precision were calculated and found to be within the acceptable range. A short run time, of <1.5 min, permits analysis of a large number of plasma samples per batch. The developed and validated method was applied to estimate AML and ATO in a bioequivalence study in healthy human volunteers. Copyright © 2018 John Wiley & Sons, Ltd.

  19. Quantitative determination of trigonelline in mouse serum by means of hydrophilic interaction liquid chromatography-MS/MS analysis: Application to a pharmacokinetic study.

    PubMed

    Szczesny, Damian; Bartosińska, Ewa; Jacyna, Julia; Patejko, Małgorzata; Siluk, Danuta; Kaliszan, Roman

    2018-02-01

    Trigonelline is a pyridine alkaloid found in fenugreek seeds and coffee beans. Most of the previous studies are concerned with the quantification of trigonelline along with other constituents in coffee herbs or beverages. Only a few have focused on its determination in animal or human tissues by applying different modes of HPLC with UV or MS detection. The aim of the study was to develop and validate a fast and simple method for trigonelline determination in serum by the use of hydrophilic interaction liquid chromatography (HILIC) with ESI-MS/MS detection. Separation of trigonelline was achieved on a Kinetex HILIC column operated at 35°C with acetonitrile-ammonium formate (10 mm, pH = 3) buffer mixture (55:45, v/v) as the mobile phase. The developed method was successfully applied to determine trigonelline concentration in mouse serum after intravenous administration of 10 mg/kg. The developed assay is sensitive (limit of detection = 1.5 ng/mL, limit of quantification = 5.0 ng/mL) and linear in a concentration range from 5.0 to 250.0 ng/mL. Sample preparation is limited to deproteinization, centrifugation and filtration. The application of the HILIC mode of chromatography with MS detection and selection of deuterated trigonelline as internal standard allowed a rapid and precise method of trigonelline quantification to be to developed. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Intergrated metabonomic study of the effects of Guizhi Fuling capsule intervention on primary dysmenorrheal using RP-UPLC-MS complementary with HILIC-UPLC-MS technique.

    PubMed

    Lang, Lang; Meng, Zhaorui; Sun, Lan; Xiao, Wei; Zhao, Longshan; Xiong, Zhili

    2018-02-01

    Guizhi Fuling capsule (GFC), developed from the traditional Chinese prescription of Guizhi Fuling Wan, has been commonly used for the treatment of primary dysmenorrhea (PD). However, the intervention effective mechanism in vivo has not been well elucidated. In this study, an integrated plasma metabonomic strategy based on RP-UPLC-MS coupled with HILIC-UPLC-MS technique has been developed to investigate the global therapeutic effects and intervention mechanisms of GFC on dysmenorrhea rats induced by oxytocin. The 20 potential biomarkers were identified and primarily related to sphingolipid metabolism, steroid hormone biosynthesis, glycerophospholipid metabolism, amino acid metabolism, lipid metabolism and energy metabolism. The results showed that the GFC has therapeutic effects on rats with dysmenorrhea via the regulation of multiple metabolic pathways. Some new potential biomarkers associated with primary dysmenorrhea such as phenylalanine, tryptophan, taurine, carnitine, betaine, creatine and creatinine have been discovered in this study for the first time. This study provides a metabonomic platform based on RP-UPLC-MS complementary to HILIC-UPLC-MS technique to investigate both nonpolar and polar compounds, so as to get a more comprehensive metabolite information to yield insight into the pathophysiology of PD and assessing the efficacy of GFC on PD rats. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Increased Circulating Levels of Vitamin D Binding Protein in MS Patients

    PubMed Central

    Rinaldi, Arturo Ottavio; Sanseverino, Isabella; Purificato, Cristina; Cortese, Antonio; Mechelli, Rosella; Francisci, Silvia; Salvetti, Marco; Millefiorini, Enrico; Gessani, Sandra; Gauzzi, Maria Cristina

    2015-01-01

    Vitamin D (vitD) low status is currently considered a main environmental factor in multiple sclerosis (MS) etiology and pathogenesis. VitD and its metabolites are highly hydrophobic and circulate mostly bound to the vitamin D binding protein (DBP) and with lower affinity to albumin, while less than 1% are in a free form. The aim of this study was to investigate whether the circulating levels of either of the two vitD plasma carriers and/or their relationship are altered in MS. We measured DBP and albumin plasma levels in 28 MS patients and 24 healthy controls. MS patients were found to have higher DBP levels than healthy subjects. Concomitant interferon beta therapy did not influence DBP concentration, and the difference with the control group was significant in both females and males. No significant correlation between DBP and albumin levels was observed either in healthy controls or in patients. These observations suggest the involvement of DBP in the patho-physiology of MS. PMID:25590278

  2. msCompare: A Framework for Quantitative Analysis of Label-free LC-MS Data for Comparative Candidate Biomarker Studies*

    PubMed Central

    Hoekman, Berend; Breitling, Rainer; Suits, Frank; Bischoff, Rainer; Horvatovich, Peter

    2012-01-01

    Data processing forms an integral part of biomarker discovery and contributes significantly to the ultimate result. To compare and evaluate various publicly available open source label-free data processing workflows, we developed msCompare, a modular framework that allows the arbitrary combination of different feature detection/quantification and alignment/matching algorithms in conjunction with a novel scoring method to evaluate their overall performance. We used msCompare to assess the performance of workflows built from modules of publicly available data processing packages such as SuperHirn, OpenMS, and MZmine and our in-house developed modules on peptide-spiked urine and trypsin-digested cerebrospinal fluid (CSF) samples. We found that the quality of results varied greatly among workflows, and interestingly, heterogeneous combinations of algorithms often performed better than the homogenous workflows. Our scoring method showed that the union of feature matrices of different workflows outperformed the original homogenous workflows in some cases. msCompare is open source software (https://trac.nbic.nl/mscompare), and we provide a web-based data processing service for our framework by integration into the Galaxy server of the Netherlands Bioinformatics Center (http://galaxy.nbic.nl/galaxy) to allow scientists to determine which combination of modules provides the most accurate processing for their particular LC-MS data sets. PMID:22318370

  3. The future of liquid chromatography-mass spectrometry (LC-MS) in metabolic profiling and metabolomic studies for biomarker discovery

    PubMed Central

    Metz, Thomas O.; Zhang, Qibin; Page, Jason S.; Shen, Yufeng; Callister, Stephen J.; Jacobs, Jon M.; Smith, Richard D.

    2008-01-01

    SUMMARY The future utility of liquid chromatography-mass spectrometry (LC-MS) in metabolic profiling and metabolomic studies for biomarker discover will be discussed, beginning with a brief description of the evolution of metabolomics and the utilization of the three most popular analytical platforms in such studies: NMR, GC-MS, and LC-MS. Emphasis is placed on recent developments in high-efficiency LC separations, sensitive electrospray ionization approaches, and the benefits to incorporating both in LC-MS-based approaches. The advantages and disadvantages of various quantitative approaches are reviewed, followed by the current LC-MS-based tools available for candidate biomarker characterization and identification. Finally, a brief prediction on the future path of LC-MS-based methods in metabolic profiling and metabolomic studies is given. PMID:19177179

  4. Quality evaluation of LC-MS/MS-based E. coli H antigen typing (MS-H) through label-free quantitative data analysis in a clinical sample setup.

    PubMed

    Cheng, Keding; Sloan, Angela; McCorrister, Stuart; Peterson, Lorea; Chui, Huixia; Drebot, Mike; Nadon, Celine; Knox, J David; Wang, Gehua

    2014-12-01

    The need for rapid and accurate H typing is evident during Escherichia coli outbreak situations. This study explores the transition of MS-H, a method originally developed for rapid H antigen typing of E. coli using LC-MS/MS of flagella digest of reference strains and some clinical strains, to E. coli isolates in clinical scenario through quantitative analysis and method validation. Motile and nonmotile strains were examined in batches to simulate clinical sample scenario. Various LC-MS/MS batch run procedures and MS-H typing rules were compared and summarized through quantitative analysis of MS-H data output for a standard method development. Label-free quantitative data analysis of MS-H typing was proven very useful for examining the quality of MS-H result and the effects of some sample carryovers from motile E. coli isolates. Based on this, a refined procedure and protein identification rule specific for clinical MS-H typing was established and validated. With LC-MS/MS batch run procedure and database search parameter unique for E. coli MS-H typing, the standard procedure maintained high accuracy and specificity in clinical situations, and its potential to be used in a clinical setting was clearly established. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Stability of Mental Toughness, Sleep Disturbances, and Physical Activity in Patients With Multiple Sclerosis (MS)—A Longitudinal and Pilot Study

    PubMed Central

    Sadeghi Bahmani, Dena; Esmaeili, Leila; Shaygannejad, Vahid; Gerber, Markus; Kesselring, Juerg; Lang, Undine E.; Holsboer-Trachsler, Edith; Brand, Serge

    2018-01-01

    Background: Previous research of patients with multiple sclerosis (MS) focused prevalently on fatigue, depression, and cognitive dysfunction during the clinical course. By contrast, research on the longer-term characteristics of physical activity (PA), psychological functioning, and sleep problems is scarce. The aims of the present study were therefore to examine changes in PA, mental toughness (MT) as a proxy of psychological functioning, and sleep disturbances over a 2-year period of time after disease onset. Methods: A total of 18 patients with diagnosed MS (mean age: M = 34.29 years) took part in this longitudinal study. First, 1–4 weeks after the first symptoms, a neurologist diagnosed the MS. Second, they completed a series of questionnaires covering socio-demographic data, PA, MT, and sleep disturbances. Third, the same questionnaires were completed again 2 years later (follow-up). Last, a neurologist assessed the degree of disability with the Expanded Disability Status Scale (EDSS). Results: Two years after MS onset, patients had lower levels of vigorous PA, but no statistically significant changes in moderate PA were observed. Further, walking time increased and sedentary time decreased. Patients with sleep disturbances at disease onset also reported poor sleep 2 years later. MT scores remained stable over time. EDSS scores worsened, though, change in EDSS was not associated with PA, MT, or sleep. Conclusions: Two years after disease onset, patients with MS reported similar MT levels and sleep disturbances. PA shifted from vigorous PA toward walking and a less sedentary lifestyle, while moderate PA remained unchanged. The pattern of results of the present pilot study suggests that at the early stage of the MS course, there is no obstacle for being physically active, nor did sleep and MT as a proxy of psychological functioning decrease in a substantial way. PMID:29867606

  6. SWATH Mass Spectrometry Performance Using Extended Peptide MS/MS Assay Libraries*

    PubMed Central

    Wu, Jemma X.; Song, Xiaomin; Pascovici, Dana; Zaw, Thiri; Care, Natasha; Krisp, Christoph; Molloy, Mark P.

    2016-01-01

    The use of data-independent acquisition methods such as SWATH for mass spectrometry based proteomics is usually performed with peptide MS/MS assay libraries which enable identification and quantitation of peptide peak areas. Reference assay libraries can be generated locally through information dependent acquisition, or obtained from community data repositories for commonly studied organisms. However, there have been no studies performed to systematically evaluate how locally generated or repository-based assay libraries affect SWATH performance for proteomic studies. To undertake this analysis, we developed a software workflow, SwathXtend, which generates extended peptide assay libraries by integration with a local seed library and delivers statistical analysis of SWATH-quantitative comparisons. We designed test samples using peptides from a yeast extract spiked into peptides from human K562 cell lysates at three different ratios to simulate protein abundance change comparisons. SWATH-MS performance was assessed using local and external assay libraries of varying complexities and proteome compositions. These experiments demonstrated that local seed libraries integrated with external assay libraries achieve better performance than local assay libraries alone, in terms of the number of identified peptides and proteins and the specificity to detect differentially abundant proteins. Our findings show that the performance of extended assay libraries is influenced by the MS/MS feature similarity of the seed and external libraries, while statistical analysis using multiple testing corrections increases the statistical rigor needed when searching against large extended assay libraries. PMID:27161445

  7. The Short Cosyntropin Test Revisited: New Normal Reference Range Using LC-MS/MS.

    PubMed

    Ueland, Grethe Å; Methlie, Paal; Øksnes, Marianne; Thordarson, Hrafnkell B; Sagen, Jørn; Kellmann, Ralf; Mellgren, Gunnar; Ræder, Maria; Dahlqvist, Per; Dahl, Sandra R; Thorsby, Per M; Løvås, Kristian; Husebye, Eystein S

    2018-04-01

    The cosyntropin test is used to diagnose adrenal insufficiency (AI) and nonclassical congenital adrenal hyperplasia (NCCAH). Current cutoffs for cortisol and 17-hydroxyprogesterone (17-OHP) are derived from nonstandardized immunoassays. Liquid chromatography tandem mass spectrometry (LC-MS/MS) offers direct measurement of steroids, prompting the need to re-establish normal ranges. The goal of this study was to define cutoff values for cortisol and 17-OHP in serum by LC-MS/MS 30 and 60 minutes after intravenous administration of 250 µg tetracosactide acetate to healthy volunteers and to compare the results with LC-MS/MS with routine immunoassays. Cosyntropin testing was performed in healthy subjects (n = 138) and in patients referred for evaluation of adrenocortical function (n = 94). Steroids were assayed by LC-MS/MS and compared with two immunoassays used in routine diagnostics (Immulite and Roche platforms). The cutoff level for cortisol was defined as the 2.5% percentile in healthy subjects not using oral estrogens (n = 121) and for 17-OHP as the 97.5% percentile. Cortisol cutoff levels for LC-MS/MS were 412 and 485 nmol/L at 30 and 60 minutes, respectively. Applying the new cutoffs, 13 of 60 (22%) subjects who had AI according to conventional criteria now had a normal test result. For 17-OHP, the cutoff levels were 8.9 and 9.0 nmol/L at 30 and 60 minutes, respectively. LC-MS/MS provides cutoff levels for cortisol and 17-OHP after cosyntropin stimulation that are lower than those based on immunoassays, possibly because cross-reactivity between steroid intermediates and cortisol is eliminated. This reduces the number of false-positive tests for AI and false-negative tests for NCCAH.

  8. Comparison of matrix effects in HPLC-MS/MS and UPLC-MS/MS analysis of nine basic pharmaceuticals in surface waters.

    PubMed

    Van De Steene, Jet C; Lambert, Willy E

    2008-05-01

    When developing an LC-MS/MS-method matrix effects are a major issue. The effect of co-eluting compounds arising from the matrix can result in signal enhancement or suppression. During method development much attention should be paid to diminishing matrix effects as much as possible. The present work evaluates matrix effects from aqueous environmental samples in the simultaneous analysis of a group of 9 specific pharmaceuticals with HPLC-ESI/MS/MS and UPLC-ESI/MS/MS: flubendazole, propiconazole, pipamperone, cinnarizine, ketoconazole, miconazole, rabeprazole, itraconazole and domperidone. When HPLC-MS/MS is used, matrix effects are substantial and can not be compensated for with analogue internal standards. For different surface water samples different matrix effects are found. For accurate quantification the standard addition approach is necessary. Due to the better resolution and more narrow peaks in UPLC, analytes will co-elute less with interferences during ionisation, so matrix effects could be lower, or even eliminated. If matrix effects are eliminated with this technique, the standard addition method for quantification can be omitted and the overall method will be simplified. Results show that matrix effects are almost eliminated if internal standards (structural analogues) are used. Instead of the time-consuming and labour-intensive standard addition method, with UPLC the internal standardization can be used for quantification and the overall method is substantially simplified.

  9. UPLC-MS/MS Analysis of Methotrexate in Human Plasma and Comparison with the Fluorescence Polarization Immunoassay.

    PubMed

    Mei, Shenghui; Zhu, Leting; Li, Xingang; Wang, Jiaqing; Jiang, Xueyun; Chen, Haiyan; Huo, Jiping; Yang, Li; Lin, Song; Zhao, Zhigang

    2017-01-01

    Methotrexate (MTX) plasma concentration is routinely monitored to guide the dosage regimen of rescue drugs. This study aims to develop and validate an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for plasma MTX analysis, and to establish its agreement with the fluorescence polarization immunoassay (FPIA) in patients with high-dose MTX therapy. Separation was achieved by gradient elution with methanol and water (0.05% formic acid) at 40°C with a run time of 3 min. The intra- and inter-day inaccuracy and imprecision of the UPLC-MS/MS method were -4.25 to 3.1 and less than 7.63%, respectively. The IS-normalized recovery and matrix effect were 87.05 to 92.81 and 124.43 to 134.57%. The correlation coefficients between UPLC-MS/MS and FPIA were greater than 0.98. The UPLC-MS/MS method was in agreement with the FPIA at high levels of MTX (1.0 - 100 μmol/L), but not at low levels (0.01 - 1.0 μmol/L). Further studies are warranted to confirm these results.

  10. Overlapping MALDI-Mass Spectrometry Imaging for In-Parallel MS and MS/MS Data Acquisition without Sacrificing Spatial Resolution

    NASA Astrophysics Data System (ADS)

    Hansen, Rebecca L.; Lee, Young Jin

    2017-09-01

    Metabolomics experiments require chemical identifications, often through MS/MS analysis. In mass spectrometry imaging (MSI), this necessitates running several serial tissue sections or using a multiplex data acquisition method. We have previously developed a multiplex MSI method to obtain MS and MS/MS data in a single experiment to acquire more chemical information in less data acquisition time. In this method, each raster step is composed of several spiral steps and each spiral step is used for a separate scan event (e.g., MS or MS/MS). One main limitation of this method is the loss of spatial resolution as the number of spiral steps increases, limiting its applicability for high-spatial resolution MSI. In this work, we demonstrate multiplex MS imaging is possible without sacrificing spatial resolution by the use of overlapping spiral steps, instead of spatially separated spiral steps as used in the previous work. Significant amounts of matrix and analytes are still left after multiple spectral acquisitions, especially with nanoparticle matrices, so that high quality MS and MS/MS data can be obtained on virtually the same tissue spot. This method was then applied to visualize metabolites and acquire their MS/MS spectra in maize leaf cross-sections at 10 μm spatial resolution. [Figure not available: see fulltext.

  11. Collagen-based proteinaceous binder-pigment interaction study under UV ageing conditions by MALDI-TOF-MS and principal component analysis.

    PubMed

    Romero-Pastor, Julia; Navas, Natalia; Kuckova, Stepanka; Rodríguez-Navarro, Alejandro; Cardell, Carolina

    2012-03-01

    This study focuses on acquiring information on the degradation process of proteinaceous binders due to ultra violet (UV) radiation and possible interactions owing to the presence of historical mineral pigments. With this aim, three different paint model samples were prepared according to medieval recipes, using rabbit glue as proteinaceus binders. One of these model samples contained only the binder, and the other two were prepared by mixing each of the pigments (cinnabar or azurite) with the binder (glue tempera model samples). The model samples were studied by applying Principal Component Analysis (PCA) to their mass spectra obtained with Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS). The complementary use of Fourier Transform Infrared Spectroscopy to study conformational changes of secondary structure of the proteinaceous binder is also proposed. Ageing effects on the model samples after up to 3000 h of UV irradiation were periodically analyzed by the proposed approach. PCA on MS data proved capable of identifying significant changes in the model samples, and the results suggested different aging behavior based on the pigment present. This research represents the first attempt to use this approach (PCA on MALDI-TOF-MS data) in the field of Cultural Heritage and demonstrates the potential benefits in the study of proteinaceous artistic materials for purposes of conservation and restoration. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Pregnancy outcomes in Lebanese women with multiple sclerosis (the LeMS study): a prospective multicentre study

    PubMed Central

    Fares, Jawad; Nassar, Anwar H; Gebeily, Souheil; Kobeissy, Firas; Fares, Youssef

    2016-01-01

    Objective The Lebanese Multiple Sclerosis (LeMS) study aims to assess the influence of pregnancy and delivery on the clinical course of multiple sclerosis (MS) in Lebanese women. Setting This prospective multicentre study took place in three MS referral university medical centres in Lebanon. Participants Included were 29 women over 18 years who had been diagnosed with MS according to the McDonald criteria, and became pregnant between 1995 and 2015. Participating women should have stopped treatment 3 months before conception and become pregnant after the onset of MS. Women were followed up from 1 year preconceptionally and for 4 years postpartum. Main outcome measures The annualised relapse rates per participant during each 3-month period during pregnancy and each year postpartum were compared with the relapse rate during the year before pregnancy using the paired two-tailed t test. p Values <0.05 were considered statistically significant for all analyses (95% CI). Results 64 full-term pregnancies were recorded. All pregnancies (100%) resulted in live births, with no complications or other diseases. In comparison with the prepregnancy year, in which the mean relapse rate±SE was 0.17±0.07, there was a significant reduction in the relapse rate during pregnancy and in the first year postpartum (p=0.02), but an increase in the rate in the second year postpartum (0.21±0.08). Thereafter, from the third year postpartum through the following fourth year, the annualised relapse rate fell slightly but did not differ from the annualised relapse rate recorded in the prepregnancy year (0.17±0.07). Conclusions Pregnancy in Lebanese women with MS does not seem to increase the risk of complications. No relapses were observed during pregnancy and in the first year postpartum; however, relapses rebounded in the second year postpartum, and over the long term, returned to the levels that preceded pregnancy. PMID:27178979

  13. Pregnancy outcomes in Lebanese women with multiple sclerosis (the LeMS study): a prospective multicentre study.

    PubMed

    Fares, Jawad; Nassar, Anwar H; Gebeily, Souheil; Kobeissy, Firas; Fares, Youssef

    2016-05-13

    The Lebanese Multiple Sclerosis (LeMS) study aims to assess the influence of pregnancy and delivery on the clinical course of multiple sclerosis (MS) in Lebanese women. This prospective multicentre study took place in three MS referral university medical centres in Lebanon. Included were 29 women over 18 years who had been diagnosed with MS according to the McDonald criteria, and became pregnant between 1995 and 2015. Participating women should have stopped treatment 3 months before conception and become pregnant after the onset of MS. Women were followed up from 1 year preconceptionally and for 4 years postpartum. The annualised relapse rates per participant during each 3-month period during pregnancy and each year postpartum were compared with the relapse rate during the year before pregnancy using the paired two-tailed t test. p Values <0.05 were considered statistically significant for all analyses (95% CI). 64 full-term pregnancies were recorded. All pregnancies (100%) resulted in live births, with no complications or other diseases. In comparison with the prepregnancy year, in which the mean relapse rate±SE was 0.17±0.07, there was a significant reduction in the relapse rate during pregnancy and in the first year postpartum (p=0.02), but an increase in the rate in the second year postpartum (0.21±0.08). Thereafter, from the third year postpartum through the following fourth year, the annualised relapse rate fell slightly but did not differ from the annualised relapse rate recorded in the prepregnancy year (0.17±0.07). Pregnancy in Lebanese women with MS does not seem to increase the risk of complications. No relapses were observed during pregnancy and in the first year postpartum; however, relapses rebounded in the second year postpartum, and over the long term, returned to the levels that preceded pregnancy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Bioanalytical method for in vitro metabolism study of repaglinide using 96-blade thin-film solid-phase microextraction and LC-MS/MS.

    PubMed

    Simões, Rodrigo Almeida; Bonato, Pierina Sueli; Mirnaghi, Fatemeh S; Bojko, Barbara; Pawliszyn, Janusz

    2015-01-01

    A high-throughput bioanalytical method using 96-blade thin film microextraction (TFME) and LC-MS/MS for the analysis of repaglinide (RPG) and two of its main metabolites was developed and used for an in vitro metabolism study. The target analytes were extracted from human microsomal medium by a 96-blade-TFME system employing the low-cost prototype 'SPME multi-sampler' using C18 coating. Method validation showed recoveries around 90% for all analytes and was linear over the concentration range of 2-1000 ng ml(-1) for RPG and of 2-500 ng ml(-1) for each RPG metabolite. The method was applied to an in vitro metabolism study of RPG employing human liver microsomes and proved to be very useful for this purpose.

  15. Sulphur fertilization influences the sulphur species composition in Allium sativum: sulphomics using HPLC-ICPMS/MS-ESI-MS/MS.

    PubMed

    Raab, Andrea; Ronzan, Marilena; Feldmann, Joerg

    2017-10-18

    Garlic (A. sativum) contains a large number of small sulphur (S)-containing metabolites, which are important for its taste and smell and vary with A. sativum variety and growth conditions. This study was designed to investigate the influence of different sulphur-fertilization regimes on low molecular weight S-species by attempting the first sulphur mass balance in A. sativum roots and bulbs using HPLC-ICPMS/MS-ESI-MS/MS. Species unspecific quantification of acid soluble S-containing metabolites was achieved using HPLC-ICP-MS/MS. For identification of the compounds, high resolution ESI-MS (Orbitrap LTQ and q-TOF) was used. The plants contained up to 54 separated sulphur-containing compounds, which constitute about 80% of the total sulphur present in A. sativum. The roots and bulbs of A. sativum contained the same compounds, but not necessarily the same amounts and proportions. The S-containing metabolites in the roots reacted more sensitively to manipulations of sulphur fertilization than those compounds in the bulbs. In addition to known compounds (e.g. γ-glutamyl-S-1-propenylcysteine) we were able to identify and partially quantify 31 compounds. Three as yet undescribed S-containing compounds were also identified and quantified for the first time. Putative structures were assigned to the oxidised forms of S-1-propenylmercaptoglutathione, S-2-propenylmercaptoglutathione, S-allyl/propenyl-containing PC-2 and 2-amino-3-[(2-carboxypropyl)sulfanyl]propanoic acid. The parallel use of ICP-MS/MS as a sulphur-specific detector and ESI-MS as a molecular detector simplifies the identification and quantification of sulphur containing metabolites without species specific standards. This non-target analysis approach enables a mass balance approach and identifies the occurrence of the so far unidentified organosulphur compounds. The experiments showed that the sulphur-fertilization regime does not influence sulphur-speciation, but the concentration of some S

  16. Simultaneous determination of mangiferin and neomangiferin in rat plasma by UPLC-MS/MS and its application for pharmacokinetic study.

    PubMed

    Qiu, Xiangjun; Zhao, Jian-Long; Hao, Cong; Yuan, Canli; Tian, Nuan; Xu, Zhi-Sheng; Zou, Ruan-Min

    2016-05-30

    In this study, a sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed to determine mangiferin and neomangiferin in rat plasma simultaneously. Chromatographic separation was carried out on an Acquity UPLC BEH C18 column and mass spectrometric analysis was performed using a Xevo TQD triple quadruple mass spectrometer coupled with an electrospray ionization (ESI) source. The MRM transitions of m/z 423.2 → 303.1 and m/z 585.0 → 273.1 were used to quantify for mangiferin and neomangiferin, respectively. The linearity of this method was found to be within the concentration range of 5-2000 ng/mL for mangiferin, and 2-1000 ng/mL for neomangiferin in rat plasma, respectively. Only 3.0 min was needed for an analytical run. This assay was used to support a preclinical study to investigate the pharmacokinetics of mangiferin and neomangiferin in rats. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Goal attainment in cognitive rehabilitation in MS patients.

    PubMed

    Hanssen, Kjersti Træland; Saltytė Benth, Jūratė; Beiske, Antonie Giæver; Landrø, Nils Inge; Hessen, Erik

    2015-01-01

    The aim of the study was to investigate the predictive value of important disease-related variables on goal attainment in cognitive rehabilitation in multiple sclerosis (MS). The possible predictive value of executive functions, neurological disability, depression and general cognitive ability was assessed, employing Goal Attainment Scaling (GAS). Fifty-seven patients with MS were assessed for executive functions, neurological disability, depression and general cognitive ability, and guided through the process of formulating GAS-goals for coping with cognitive challenges in everyday life during a four week in-patient cognitive rehabilitation programme. GAS-goal attainment was scored during biweekly follow-up calls in the first three months post-discharge from the rehabilitation centre, and finally at seven months after the start of the rehabilitation. Consistent with the first study hypothesis MS patients succeeded in formulating and achieving GAS goals for coping with cognitive problems in everyday life. The patients were able to maintain a satisfactory level of goal attainment from the first measurement point after six weeks to seven months after the start of the rehabilitation. However, contrary to the second hypothesis, attainment of GAS goals was not predicted by executive functions. Neither was it predicted by neurological disability, depression or general cognitive ability. The findings suggest that GAS may be a practical and robust method in cognitive rehabilitation in MS patients, regardless of important disease-related characteristics.

  18. Importance of MS selectivity and chromatographic separation in LC-MS/MS-based methods when investigating pharmaceutical metabolites in water. Dipyrone as a case of study.

    PubMed

    Ibáñez, M; Gracia-Lor, E; Sancho, J V; Hernández, F

    2012-08-01

    Pharmaceuticals are emerging contaminants of increasing concern because of their presence in the aquatic environment and potential to reach drinking-water sources. After human and/or veterinary consumption, pharmaceuticals can be excreted in unchanged form, as the parent compound, and/or as free or conjugated metabolites. Determination of most pharmaceuticals and metabolites in the environment is commonly made by liquid chromatography (LC) coupled to mass spectrometry (MS). LC coupled to tandem MS is the technique of choice nowadays in this field. The acquisition of two selected reaction monitoring (SRM) transitions together with the retention time is the most widely accepted criterion for a safe quantification and confirmation assay. However, scarce attention is normally paid to the selectivity of the selected transitions as well as to the chromatographic separation. In this work, the importance of full spectrum acquisition high-resolution MS data using a hybrid quadrupole time-of-flight analyser and/or a suitable chromatographic separation (to reduce the possibility of co-eluting interferences) is highlighted when investigating pharmaceutical metabolites that share common fragment ions. For this purpose, the analytical challenge associated to the determination of metabolites of the widely used analgesic dipyrone (also known as metamizol) in urban wastewater is discussed. Examples are given on the possibilities of reporting false positives of dypirone metabolites by LC-MS/MS under SRM mode due to a wrong assignment of identity of the compounds detected. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Development and validation of sensitive LC/MS/MS method for quantitative bioanalysis of levonorgestrel in rat plasma and application to pharmacokinetics study.

    PubMed

    Ananthula, Suryatheja; Janagam, Dileep R; Jamalapuram, Seshulatha; Johnson, James R; Mandrell, Timothy D; Lowe, Tao L

    2015-10-15

    Rapid, sensitive, selective and accurate LC/MS/MS method was developed for quantitative determination of levonorgestrel (LNG) in rat plasma and further validated for specificity, linearity, accuracy, precision, sensitivity, matrix effect, recovery efficiency and stability. Liquid-liquid extraction procedure using hexane:ethyl acetate mixture at 80:20 v:v ratio was employed to efficiently extract LNG from rat plasma. Reversed phase Luna column C18(2) (50×2.0mm i.d., 3μM) installed on a AB SCIEX Triple Quad™ 4500 LC/MS/MS system was used to perform chromatographic separation. LNG was identified within 2min with high specificity. Linear calibration curve was drawn within 0.5-50ng·mL(-1) concentration range. The developed method was validated for intra-day and inter-day accuracy and precision whose values fell in the acceptable limits. Matrix effect was found to be minimal. Recovery efficiency at three quality control (QC) concentrations 0.5 (low), 5 (medium) and 50 (high) ng·mL(-1) was found to be >90%. Stability of LNG at various stages of experiment including storage, extraction and analysis was evaluated using QC samples, and the results showed that LNG was stable at all the conditions. This validated method was successfully used to study the pharmacokinetics of LNG in rats after SubQ injection, providing its applicability in relevant preclinical studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. SWATH Mass Spectrometry Performance Using Extended Peptide MS/MS Assay Libraries.

    PubMed

    Wu, Jemma X; Song, Xiaomin; Pascovici, Dana; Zaw, Thiri; Care, Natasha; Krisp, Christoph; Molloy, Mark P

    2016-07-01

    The use of data-independent acquisition methods such as SWATH for mass spectrometry based proteomics is usually performed with peptide MS/MS assay libraries which enable identification and quantitation of peptide peak areas. Reference assay libraries can be generated locally through information dependent acquisition, or obtained from community data repositories for commonly studied organisms. However, there have been no studies performed to systematically evaluate how locally generated or repository-based assay libraries affect SWATH performance for proteomic studies. To undertake this analysis, we developed a software workflow, SwathXtend, which generates extended peptide assay libraries by integration with a local seed library and delivers statistical analysis of SWATH-quantitative comparisons. We designed test samples using peptides from a yeast extract spiked into peptides from human K562 cell lysates at three different ratios to simulate protein abundance change comparisons. SWATH-MS performance was assessed using local and external assay libraries of varying complexities and proteome compositions. These experiments demonstrated that local seed libraries integrated with external assay libraries achieve better performance than local assay libraries alone, in terms of the number of identified peptides and proteins and the specificity to detect differentially abundant proteins. Our findings show that the performance of extended assay libraries is influenced by the MS/MS feature similarity of the seed and external libraries, while statistical analysis using multiple testing corrections increases the statistical rigor needed when searching against large extended assay libraries. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. [Effect of Gegen Qinlian decoction on hepatic cytochrome CYP450 isozymes in rats by HPLC-MS/MS].

    PubMed

    Liu, Zi-hua; An, Rui; Zhang, Yi-zhu; Gu, Qing-qing; You, Li-sha; Wang, Xin-hong

    2015-08-01

    To study the effect of Gegen Qinlian decoction and its major effective components on five hepatic microsomal CYP450 isozymes in rats. The in vitro hepatic microsomal incubation technique was used to co-culture Gegen Qinlian decoction and its major effective components together with each probe substrate. HPLC-MS/MS was used to establish the analytical method for metabolites of the five isoform probe substrates of CYP450 isozymes, detect the linearity among micoromal protein concentration, incubation time and metabolite formation amount. And HPLC-MS/MS was applied to determine the formation rate (V) of corresponding metabolites (acetaminophen, 4-OH-chlorzoxazone, dextrophan, 6-OH-chlorzoxazone and 6β-hydroxytestosterone) specific probe substrates of the five isoform probe substrates of CYP450 isozymes (phenacetin, polbutamide, dextromethorphan, chlorzoxazone, testosterone), in order to determine the activity of each isozyme. The result showed good linearity among acetaminophen, 4-OH-tolbutamide, dextrophan, 6-OH-chlorzoxazone and 6β-hydroxytestosterone, satisfactory precision, stability and average recovery, suggesting the method was feasible. The optimized in vitro microsomal incubation conditions conformed to the requirements in the guideline of drug-drug interaction. Gegen Qinlian decoction showed different degrees of inhibitor effect on 5 CYP450 isoforms (CYP1A2, CYP2C11, CYP2D2, CYP2E1, CYP3A1/2). Its major effective component berberine could inhibit each CYP450 isoform at high concentrations (except for CYP1A2, CYP3A1/2).

  2. Pediatric MS

    MedlinePlus

    ... Disease T Cells d What Causes MS? Disproved Theories Viruses Clusters d Who Gets MS? Pediatric MS ... Community at MSconnection.org Join a Local Support Group Peer Connections: One-on-One Edward M. Dowd ...

  3. A Comparison of DESI-MS and LC-MS for the Lipidomic Profiling of Human Cancer Tissue

    NASA Astrophysics Data System (ADS)

    Abbassi-Ghadi, Nima; Jones, Emrys A.; Gomez-Romero, Maria; Golf, Ottmar; Kumar, Sacheen; Huang, Juzheng; Kudo, Hiromi; Goldin, Rob D.; Hanna, George B.; Takats, Zoltan

    2016-02-01

    In this study, we make a direct comparison between desorption electrospray ionization-mass spectrometry (DESI-MS) and ultraperformance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) platforms for the profiling of glycerophospholipid (GPL) species in esophageal cancer tissue. In particular, we studied the similarities and differences in the range of GPLs detected and the congruency of their relative abundances as detected by each analytical platform. The main differences between mass spectra of the two modalities were found to be associated with the variance in adduct formation of common GPLs, rather than the presence of different GPL species. Phosphatidylcholines as formate adducts in UPLC-ESI-MS accounted for the majority of differences in negative ion mode and alkali metal adducts of phosphatidylcholines in DESI-MS for positive ion mode. Comparison of the relative abundance of GPLs, normalized to a common peak, revealed a correlation coefficient of 0.70 ( P < 0.001). The GPL profile detected by DESI-MS is congruent to UPLC-ESI-MS, which reaffirms the role of DESI-MS for lipidomic profiling and a potential premise for quantification.

  4. The use of in vitro technologies coupled with high resolution accurate mass LC-MS for studying drug metabolism in equine drug surveillance.

    PubMed

    Scarth, James P; Spencer, Holly A; Timbers, Sarah E; Hudson, Simon C; Hillyer, Lynn L

    2010-01-01

    The detection of drug abuse in horseracing often requires knowledge of drug metabolism, especially if urine is the matrix of choice. In this study, equine liver/lung microsomes/S9 tissue fractions were used to study the phase I metabolism of eight drugs of relevance to equine drug surveillance (acepromazine, azaperone, celecoxib, fentanyl, fluphenazine, mepivacaine, methylphenidate and tripelennamine). In vitro samples were analyzed qualitatively alongside samples originating from in vivo administrations using LC-MS on a high resolution accurate mass Thermo Orbitrap Discovery instrument and by LC-MS/MS on an Applied Biosystems Sciex 5500 Q Trap.Using high resolution accurate mass full-scan analysis on the Orbitrap, the in vitro systems were found to generate at least the two most abundant phase I metabolites observed in vitro for all eight drugs studied. In the majority of cases, in vitro experiments were also able to generate the minor in vivo metabolites and sometimes metabolites that were only observed in vitro. More detailed analyses of fentanyl incubates using LC-MS/MS showed that it was possible to generate good quality spectra from the metabolites generated in vitro. These data support the suggestion of using in vitro incubates as metabolite reference material in place of in vivo post-administration samples in accordance with new qualitative identification guidelines in the 2009 International Laboratory Accreditation Cooperation-G7 (ILAC-G7) document.In summary, the in vitro and in vivo phase I metabolism results reported herein compare well and demonstrate the potential of in vitro studies to compliment, refine and reduce the existing equine in vivo paradigm. © 2010 John Wiley & Sons, Ltd.

  5. Urinary amino acid analysis: a comparison of iTRAQ-LC-MS/MS, GC-MS, and amino acid analyzer.

    PubMed

    Kaspar, Hannelore; Dettmer, Katja; Chan, Queenie; Daniels, Scott; Nimkar, Subodh; Daviglus, Martha L; Stamler, Jeremiah; Elliott, Paul; Oefner, Peter J

    2009-07-01

    Urinary amino acid analysis is typically done by cation-exchange chromatography followed by post-column derivatization with ninhydrin and UV detection. This method lacks throughput and specificity. Two recently introduced stable isotope ratio mass spectrometric methods promise to overcome those shortcomings. Using two blinded sets of urine replicates and a certified amino acid standard, we compared the precision and accuracy of gas chromatography/mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) of propyl chloroformate and iTRAQ derivatized amino acids, respectively, to conventional amino acid analysis. The GC-MS method builds on the direct derivatization of amino acids in diluted urine with propyl chloroformate, GC separation and mass spectrometric quantification of derivatives using stable isotope labeled standards. The LC-MS/MS method requires prior urinary protein precipitation followed by labeling of urinary and standard amino acids with iTRAQ tags containing different cleavable reporter ions distinguishable by MS/MS fragmentation. Means and standard deviations of percent technical error (%TE) computed for 20 amino acids determined by amino acid analyzer, GC-MS, and iTRAQ-LC-MS/MS analyses of 33 duplicate and triplicate urine specimens were 7.27+/-5.22, 21.18+/-10.94, and 18.34+/-14.67, respectively. Corresponding values for 13 amino acids determined in a second batch of 144 urine specimens measured in duplicate or triplicate were 8.39+/-5.35, 6.23+/-3.84, and 35.37+/-29.42. Both GC-MS and iTRAQ-LC-MS/MS are suited for high-throughput amino acid analysis, with the former offering at present higher reproducibility and completely automated sample pretreatment, while the latter covers more amino acids and related amines.

  6. PGCA: An algorithm to link protein groups created from MS/MS data

    PubMed Central

    Sasaki, Mayu; Hollander, Zsuzsanna; Smith, Derek; McManus, Bruce; McMaster, W. Robert; Ng, Raymond T.; Cohen Freue, Gabriela V.

    2017-01-01

    The quantitation of proteins using shotgun proteomics has gained popularity in the last decades, simplifying sample handling procedures, removing extensive protein separation steps and achieving a relatively high throughput readout. The process starts with the digestion of the protein mixture into peptides, which are then separated by liquid chromatography and sequenced by tandem mass spectrometry (MS/MS). At the end of the workflow, recovering the identity of the proteins originally present in the sample is often a difficult and ambiguous process, because more than one protein identifier may match a set of peptides identified from the MS/MS spectra. To address this identification problem, many MS/MS data processing software tools combine all plausible protein identifiers matching a common set of peptides into a protein group. However, this solution introduces new challenges in studies with multiple experimental runs, which can be characterized by three main factors: i) protein groups’ identifiers are local, i.e., they vary run to run, ii) the composition of each group may change across runs, and iii) the supporting evidence of proteins within each group may also change across runs. Since in general there is no conclusive evidence about the absence of proteins in the groups, protein groups need to be linked across different runs in subsequent statistical analyses. We propose an algorithm, called Protein Group Code Algorithm (PGCA), to link groups from multiple experimental runs by forming global protein groups from connected local groups. The algorithm is computationally inexpensive and enables the connection and analysis of lists of protein groups across runs needed in biomarkers studies. We illustrate the identification problem and the stability of the PGCA mapping using 65 iTRAQ experimental runs. Further, we use two biomarker studies to show how PGCA enables the discovery of relevant candidate protein group markers with similar but non-identical compositions

  7. Expert system for computer-assisted annotation of MS/MS spectra.

    PubMed

    Neuhauser, Nadin; Michalski, Annette; Cox, Jürgen; Mann, Matthias

    2012-11-01

    An important step in mass spectrometry (MS)-based proteomics is the identification of peptides by their fragment spectra. Regardless of the identification score achieved, almost all tandem-MS (MS/MS) spectra contain remaining peaks that are not assigned by the search engine. These peaks may be explainable by human experts but the scale of modern proteomics experiments makes this impractical. In computer science, Expert Systems are a mature technology to implement a list of rules generated by interviews with practitioners. We here develop such an Expert System, making use of literature knowledge as well as a large body of high mass accuracy and pure fragmentation spectra. Interestingly, we find that even with high mass accuracy data, rule sets can quickly become too complex, leading to over-annotation. Therefore we establish a rigorous false discovery rate, calculated by random insertion of peaks from a large collection of other MS/MS spectra, and use it to develop an optimized knowledge base. This rule set correctly annotates almost all peaks of medium or high abundance. For high resolution HCD data, median intensity coverage of fragment peaks in MS/MS spectra increases from 58% by search engine annotation alone to 86%. The resulting annotation performance surpasses a human expert, especially on complex spectra such as those of larger phosphorylated peptides. Our system is also applicable to high resolution collision-induced dissociation data. It is available both as a part of MaxQuant and via a webserver that only requires an MS/MS spectrum and the corresponding peptides sequence, and which outputs publication quality, annotated MS/MS spectra (www.biochem.mpg.de/mann/tools/). It provides expert knowledge to beginners in the field of MS-based proteomics and helps advanced users to focus on unusual and possibly novel types of fragment ions.

  8. Expert System for Computer-assisted Annotation of MS/MS Spectra*

    PubMed Central

    Neuhauser, Nadin; Michalski, Annette; Cox, Jürgen; Mann, Matthias

    2012-01-01

    An important step in mass spectrometry (MS)-based proteomics is the identification of peptides by their fragment spectra. Regardless of the identification score achieved, almost all tandem-MS (MS/MS) spectra contain remaining peaks that are not assigned by the search engine. These peaks may be explainable by human experts but the scale of modern proteomics experiments makes this impractical. In computer science, Expert Systems are a mature technology to implement a list of rules generated by interviews with practitioners. We here develop such an Expert System, making use of literature knowledge as well as a large body of high mass accuracy and pure fragmentation spectra. Interestingly, we find that even with high mass accuracy data, rule sets can quickly become too complex, leading to over-annotation. Therefore we establish a rigorous false discovery rate, calculated by random insertion of peaks from a large collection of other MS/MS spectra, and use it to develop an optimized knowledge base. This rule set correctly annotates almost all peaks of medium or high abundance. For high resolution HCD data, median intensity coverage of fragment peaks in MS/MS spectra increases from 58% by search engine annotation alone to 86%. The resulting annotation performance surpasses a human expert, especially on complex spectra such as those of larger phosphorylated peptides. Our system is also applicable to high resolution collision-induced dissociation data. It is available both as a part of MaxQuant and via a webserver that only requires an MS/MS spectrum and the corresponding peptides sequence, and which outputs publication quality, annotated MS/MS spectra (www.biochem.mpg.de/mann/tools/). It provides expert knowledge to beginners in the field of MS-based proteomics and helps advanced users to focus on unusual and possibly novel types of fragment ions. PMID:22888147

  9. In vitro and in vivo metabolic investigation of the Palbociclib by UHPLC-Q-TOF/MS/MS and in silico toxicity studies of its metabolites.

    PubMed

    Chavan, Balasaheb B; Tiwari, Shristy; G, Shankar; Nimbalkar, Rakesh D; Garg, Prabha; R, Srinivas; Talluri, M V N Kumar

    2018-05-14

    Palbociclib (PAB) is a CDK4/6 inhibitor and U. S Food and Drug Administration (FDA) granted regular approval for the treatment of hormone receptor (HR) positive, metastatic breast cancer in combination with an aromatase inhibitor in postmenopausal women. Metabolite identification is a crucial aspect during drug discovery and development as the drug metabolites may be pharmacologically active or possess toxicological activity. As there are no reports on the metabolism studies of the PAB, the present study focused on investigation of the in vitro and in vivo metabolic fate of the drug. The in vitro metabolism studies were carried out by using microsomes (HLM and RLM) and S9 fractions (Human and rat). The in vivo metabolism of the drug was studied by administration of the PAB orally to the Sprague-Dawley rats followed by analysis of urine, faeces and plasma samples. The sample preparation includes simple protein precipitation (PP) followed by solid phase extraction (SPE). The extracted samples were analyzed by ultrahigh-performance liquid chromatography-quadruple time-of-flight tandem mass spectrometry (UHPLC/Q-TOF/MS/MS). A total of 14 metabolites were detected in in vivo matrices. The PAB was metabolized via hydroxylation, oxidation, sulphation, N-dealkylation, acetylation and carbonylation pathways. A few of the metabolites were also detected in in vitro samples. Metabolite identification and characterization were performed by using UHPLC/Q-TOF/MS/MS in combination with HRMS data. To identify the toxicity potential of these metabolites, in silico toxicity assessment was carried out using TOPKAT and DEREK softwares. Copyright © 2018. Published by Elsevier B.V.

  10. Site-specific radical formation in DNA induced by Cu(II)-H2O2 oxidizing system, using ESR, Immuno-spin trapping, LC/MS and MS/MS

    PubMed Central

    Bhattacharjee, Suchandra; Deterding, Leesa J.; Chatterjee, Saurabh; Jiang, JinJie; Ehrenshaft, Marilyn; Lardinois, Olivier; Ramirez, Dario C.; Tomer, Kenneth B.; Mason, Ronald P.

    2011-01-01

    Oxidative stress-related damage to the DNA macromolecule produces a multitude of lesions that are implicated in mutagenesis, carcinogenesis, reproductive cell death and aging. Many of these lesions have been studied and characterized by various techniques. Of the techniques that are available, the comet assay, HPLC-EC, GC-MS, HPLC-MS and especially HPLC-MS/MS remain the most widely used and have provided invaluable information on these lesions. However, accurate measurement of DNA damage has been a matter of debate. In particular, there have been reports of artifactual oxidation leading to erroneously high damage estimates. Further, most of these techniques measure the end product of a sequence of events and thus provide only limited information on the initial radical mechanism. We report here a qualitative measurement of DNA damage induced by a Cu(II)-H2O2 oxidizing system using immuno spin-trapping (IST) with EPR, MS and MS/MS. The radical generated is trapped by DMPO immediately upon formation. The DMPO adduct formed is initially EPR active but subsequently is oxidized to the stable nitrone, which can then be detected by IST and further characterized by MS and MS/MS. PMID:21382477

  11. The MS@Work study: a 3-year prospective observational study on factors involved with work participation in patients with relapsing-remitting Multiple Sclerosis.

    PubMed

    van der Hiele, Karin; van Gorp, Dennis A M; Heerings, Marco A P; van Lieshout, Irma; Jongen, Peter J; Reneman, Michiel F; van der Klink, Jac J L; Vosman, Frans; Middelkoop, Huub A M; Visser, Leo H

    2015-08-12

    Multiple Sclerosis (MS) is the most common cause of neurological disability in young and middle-aged adults. At this stage in life most people are in the midst of their working career. The majority of MS patients are unable to retain employment within 10 years from disease onset. Leading up to unemployment, many may experience a reduction in hours or work responsibilities and increased time missed from work. The MS@Work study examines various factors that may influence work participation in relapsing-remitting MS patients, including disease-related factors, the working environment and personal factors. The MS@Work study is a multicenter, 3-year prospective observational study on work participation in patients with relapsing-remitting MS. We aim to include 350 patients through 15-18 MS outpatient clinics in the Netherlands. Eligible participants are 18 years and older, and either currently employed or within three years since their last employment. At baseline and after 1, 2 and 3 years, the participants are asked to complete online questionnaires (including questions on work participation, work problems and accommodations, cognitive and physical ability, anxiety, depression, psychosocial stress, quality of life, fatigue, empathy, personality traits and coping strategies) and undergo cognitive and neurological examinations. After six months, patients are requested to only complete online questionnaires. Patient perspectives on maintaining and improving work participation and reasons to stop working are gathered through semi-structured interviews in a sub-group of patients. Prospective studies with long-term follow-up on work participation in MS are rare, or take into account a limited number of factors. The MS@Work study provides a 3-year follow-up on various factors that may influence work participation in patients with relapsing-remitting MS. We aim to identify factors that relate to job loss and to provide information about preventative measures for physicians

  12. Urinary Amino Acid Analysis: A Comparison of iTRAQ®-LC-MS/MS, GC-MS, and Amino Acid Analyzer

    PubMed Central

    Kaspar, Hannelore; Dettmer, Katja; Chan, Queenie; Daniels, Scott; Nimkar, Subodh; Daviglus, Martha L.; Stamler, Jeremiah; Elliott, Paul; Oefner, Peter J.

    2009-01-01

    Urinary amino acid analysis is typically done by cation-exchange chromatography followed by post-column derivatization with ninhydrin and UV detection. This method lacks throughput and specificity. Two recently introduced stable isotope ratio mass spectrometric methods promise to overcome those shortcomings. Using two blinded sets of urine replicates and a certified amino acid standard, we compared the precision and accuracy of gas chromatography/mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) of propyl chloroformate and iTRAQ® derivatized amino acids, respectively, to conventional amino acid analysis. The GC-MS method builds on the direct derivatization of amino acids in diluted urine with propyl chloroformate, GC separation and mass spectrometric quantification of derivatives using stable isotope labeled standards. The LC-MS/MS method requires prior urinary protein precipitation followed by labeling of urinary and standard amino acids with iTRAQ® tags containing different cleavable reporter ions distinguishable by MS/MS fragmentation. Means and standard deviations of percent technical error (%TE) computed for 20 amino acids determined by amino acid analyzer, GC-MS, and iTRAQ®-LC-MS/MS analyses of 33 duplicate and triplicate urine specimens were 7.27±5.22, 21.18±10.94, and 18.34±14.67, respectively. Corresponding values for 13 amino acids determined in a second batch of 144 urine specimens measured in duplicate or triplicate were 8.39±5.35, 6.23±3.84, and 35.37±29.42. Both GC-MS and iTRAQ®-LC-MS/MS are suited for high-throughput amino acid analysis, with the former offering at present higher reproducibility and completely automated sample pretreatment, while the latter covers more amino acids and related amines. PMID:19481989

  13. "Cure" for multiple sclerosis (MS)-Evolving views of therapy goals in patients on different stages of the disease: A pilot study in a cohort of Polish MS patients.

    PubMed

    Chacińska, Weronika; Brzostowska, Marta; Nojszewska, Monika; Podlecka-Piętowska, Aleksandra; Jędrzejczak, Wiesław W; Snarski, Emilian

    2017-06-01

    New aggressive treatments promise improvement of results in the treatment of multiple sclerosis (MS), however, with high risk of serious complications. In this study, we analyzed patients' acceptance for risks connected with the MS treatment. The study was designed as a prospective nonanonymous online questionnaire. Responders were asked about the definition of the "cure" for MS and crucial goals in the treatment. One hundred and eighty patients filled in the questionnaire (129 women and 51 men), and the mean age was 33 years ( SD  = 10.29). The MS forms were as follows: relapsing-remitting (65%), secondary progressive (14%), primary progressive (10%), and other (11%), with mean EDSS score of 3 points ( SD  = 2.6). For 50% of the patients, relief of symptoms such as fatigue (72%), paresis (66%), and balance disorders (65%) was synonymous with "cure." The patients with faster progression of the disease were likely to accept risky "curative" treatments-with average 68% accepted mortality risk ( p  = .003). Over 81% of patients accepted mortality rates over 1% for the treatment that achieves self-defined cure. The study shows that the MS patients are likely to accept even very risky treatments as long as they promise patient-defined "cure."

  14. Ultratrace LC-MS/MS analysis of segmented calf hair for retrospective assessment of time of clenbuterol administration in Agriforensics.

    PubMed

    Duvivier, Wilco F; van Beek, Teris A; Meijer, Thijs; Peeters, Ruth J P; Groot, Maria J; Sterk, Saskia S; Nielen, Michel W F

    2015-01-21

    In agriforensics, time of administration is often debated when illegal drug residues, such as clenbuterol, are found in frequently traded cattle. In this proof-of-concept work, the feasibility of obtaining retrospective timeline information from segmented calf tail hair analyses has been studied. First, an ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) hair analysis method was adapted to accommodate smaller sample sizes and in-house validated. Then, longitudinal 1 cm segments of calf tail hair were analyzed to obtain clenbuterol concentration profiles. The profiles found were in good agreement with calculated, theoretical positions of the clenbuterol residues along the hair. Following assessment of the average growth rate of calf tail hair, time of clenbuterol administration could be retrospectively determined from segmented hair analysis data. The data from the initial animal treatment study (n = 2) suggest that time of treatment can be retrospectively estimated with an error of 3-17 days.

  15. ms_lims, a simple yet powerful open source laboratory information management system for MS-driven proteomics.

    PubMed

    Helsens, Kenny; Colaert, Niklaas; Barsnes, Harald; Muth, Thilo; Flikka, Kristian; Staes, An; Timmerman, Evy; Wortelkamp, Steffi; Sickmann, Albert; Vandekerckhove, Joël; Gevaert, Kris; Martens, Lennart

    2010-03-01

    MS-based proteomics produces large amounts of mass spectra that require processing, identification and possibly quantification before interpretation can be undertaken. High-throughput studies require automation of these various steps, and management of the data in association with the results obtained. We here present ms_lims (http://genesis.UGent.be/ms_lims), a freely available, open-source system based on a central database to automate data management and processing in MS-driven proteomics analyses.

  16. Determination of ambroxol in human plasma using LC-MS/MS.

    PubMed

    Kim, Hohyun; Yoo, Jeong-Yeon; Han, Sang Beom; Lee, Hee Joo; Lee, Kyung Ryul

    2003-06-01

    A sensitive and selective liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the quantification of ambroxol in human plasma. Domperidone was used as internal standard, with plasma samples extracted using diethyl ether under basic condition. A centrifuged upper layer was then evaporated and reconstituted with 200 microl methanol. The reconstituted samples were injected into a C(18) XTerra MS column (2.1 x 30 mm) with 3.5 microm particle size. The analytical column lasted for at least 600 injections. The mobile phase was composed of 20 mM ammonium acetate in 90% acetonitrile (pH 8.8), with flow rate at 250 microl/min. The mass spectrometer was operated in positive ion mode using turbo electrospray ionization. Nitrogen was used as the nebulizer, curtain, collision, and auxiliary gases. Using MS/MS with multiple reaction monitoring (MRM) mode, ambroxol was detected without severe interferences from plasma matrix. Ambroxol produced a protonated precursor ion ([M+H](+)) at m/z 379 and a corresponding product ion at m/z 264. And internal standard (domperidone) produced a protonated precursor ion ([M+H](+)) at m/z 426 and a corresponding product ion at m/z 174. Detection of ambroxol in human plasma was accurate and precise, with quantification limit at 0.2 ng/ml. This method has been successfully applied to a study of ambroxol in human specimens.

  17. Identification of recombinant human EPO variants in greyhound plasma and urine by ELISA, LC-MS/MS and western blotting: a comparative study.

    PubMed

    Timms, Mark; Steel, Rohan; Vine, John

    2016-02-01

    The recombinant human erythropoietins epoetin alfa (Eprex®), darbepoetin (Aranesp®) and methoxy polyethylene glycol-epoetin beta (Mircera®) were administered to greyhounds for 7, 10 and 14 days respectively. Blood and urine samples were collected and analysed for erythropoietin by ELISA, LC-MS/MS and western blotting. Limits of confirmation in plasma for western blotting and LC-MS/MS methods ranged from a low of 2.5mIU/mL, and closely matched the sensitivity of ELISA screening. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Quantification of desoxyrhapontigenin (4-methoxyresveratrol) in rat plasma by LC-MS/MS: Application to pre-clinical pharmacokinetic study.

    PubMed

    Dai, Yu; Tan, Amanda Li Cheng; Chen, Huan; Ong, Pei Shi; Xiang, Xiaoqiang; Wu, Jinzhu; Lin, Hai-Shu

    2018-05-10

    Desoxyrhapontigenin (DRG, 4-methoxyresveratrol or trans-3,5-dihydroxy-4'-methoxystilbene) is a naturally occurring resveratrol (RES) derivative with a variety of biological activities. To facilitate its further medicinal exploration, a reliable LC-MS/MS method was developed and validated for the quantification of DRG in rat plasma using heavy isotope labelled RES as an internal standard. The ESI was operated in its negative ion mode while DRG and RES were determined by multiple reaction monitoring (MRM) using precursor-to-product ion transitions of m/z 241.1 → 180.8 and m/z 233.0 → 191.0, respectively. This LC-MS/MS method displayed excellent selectivity, sensitivity (LLOQ = 2.5 ng/ml), accuracy (both intra- and interday mean analytical recovery within 100 ± 15%) and precision (both intra- and interday CV < 15%). The mean matrix factors were all within 1.000 ± 0.150 with CV < 15%. The pharmacokinetic profiles of DRG were subsequently examined in Sprague-Dawley rats. Upon intravenous administration (4 or 10 mg/kg), DRG displayed very rapid clearance (Cl = 338 ± 66 or 275 ± 30 ml/min/kg) and short mean residence time (MRT = 12.9 ± 4.7 or 10.4 ± 0.5 min). After oral administration of DRG fully solubilized by 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), the plasma profiles of DRG were highly erratic with a low absolute bioavailability (F < 9.83 ± 5.31%). When DRG was given at a higher dose (50 mg/kg) in suspension form, the F was increased to 24.1 ± 5.6%. The pharmacokinetic comparison among DRG, RES and some of its hydroxyl analogues stilbenes was performed. The information obtained from this study will facilitate further exploration on DRG as well as other RES derivatives. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Selenium speciation analysis of Misgurnus anguillicaudatus selenoprotein by HPLC-ICP-MS and HPLC-ESI-MS/MS

    USDA-ARS?s Scientific Manuscript database

    Analytical methods for selenium (Se) speciation were developed using high performance liquid chromatography (HPLC) coupled to either inductively coupled plasma mass spectrometry (ICP-MS) or electrospray ionization tandem mass spectrometry (ESI-MS/MS). Separations of selenomethionine (Se-Met) and sel...

  20. LC-MS/MS and GC-MS methods in propofol detection: Evaluation of the two analytical procedures.

    PubMed

    Vaiano, Fabio; Serpelloni, Giovanni; Focardi, Martina; Fioravanti, Alessia; Mari, Francesco; Bertol, Elisabetta

    2015-11-01

    Propofol is a short-acting hypnotic agent that is commonly used to induce and maintain anesthesia. Propofol abuse and its involvement in suicide deaths have increased in recent years, especially among healthcare personnel. An example is the suicide of a 61-year-old nurse found with a propofol drip in his left arm. We describe the postmortem concentration of propofol in various tissues (femoral and cardiac blood, bile, urine, brain, and liver) and in the drip. The toxicological analyses were performed through two analytical methods, differing in derivatization reaction and in instrumentation: silylation for gas chromatograph-mass spectrometer (GC-MS), as routinely performed in our laboratory for this kind of analyses (lower limits of quantification-LLOQ-in urine and blood: 0.3 and 5ng/ml); for liquid chromatograph-tandem mass spectrometer (LC-MS/MS) an innovative azo-coupling derivatization (LLOQ: 0.0004 and 0.1ng/ml). This latter produces an azo-derivative (molecular composition: C18H22ON2; molecular weight: 282Da) highly ionizable in electro-spray ion source, both in negative and positive ionizations. These two methods were compared to evaluate the effectiveness of this new LC-MS/MS analysis. An acidic hydrolysis (HCl 6N, 100°C, and 1h) was performed for the biological samples (1ml or 1g) irrespective of the analytical method applied. The drip content was extracted adding phosphate buffer (pH 8) and a dichloromethane/ethylacetate 8:2 (v:v) mixture. Derivatization steps were: silylation with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)+tetramethylammonium hydroxide (TMAH) for GC-MS; regarding LC-MS/MS, azo-coupling reaction with the aryl-diazonium salt (0-5°C, and 30min). The analyses were achieved in selected-ion monitoring for GC-MS (m/z, 235,250,73 propofol"; m/z, 252,267,27 propofol-d17) and in multiple reaction monitoring ([M-H](-): m/z 283→241,77, azo-propofol; m/z 299→251,77, azo-propofol-d17) for LC-MS/MS. Autopsy showed no significant findings

  1. A randomized, controlled, single-blind, 6-month pilot study to evaluate the efficacy of MS-Line!: a cognitive rehabilitation programme for patients with multiple sclerosis.

    PubMed

    Gich, Jordi; Freixanet, Jordi; García, Rafael; Vilanova, Joan Carles; Genís, David; Silva, Yolanda; Montalban, Xavier; Ramió-Torrentà, Lluís

    2015-09-01

    MS-Line! was created to provide an effective treatment for cognitive impairment in multiple sclerosis (MS) patients. To assess the efficacy of MS-Line!. A randomized, controlled, single-blind, 6-month pilot study. Patients were randomly assigned to an experimental group (cognitive rehabilitation with the programme) or to a control group (no cognitive rehabilitation). Randomization was stratified by cognitive impairment level. Cognitive assessment included: selective reminding test, 10/36 spatial recall test (10/36 SPART), symbol digit modalities test, paced auditory serial addition test, word list generation (WLG), FAS test, subtests of WAIS-III, Boston naming test (BNT), and trail making test (TMT). Forty-three patients (22 in the experimental group, 21 in the control group) were analyzed. Covariance analysis showed significant differences in 10/36 SPART (P=0.0002), 10/36 SPART delayed recall (P=0.0021), WLG (P=0.0123), LNS (P=0.0413), BNT (P=0.0007) and TMT-A (P=0.010) scores between groups. The study showed a significant improvement related to learning and visual memory, executive functions, attention and information processing speed, and naming ability in those patients who received cognitive rehabilitation. The results suggest that MS-Line! is effective in improving cognitive impairment in MS patients. © The Author(s), 2015.

  2. A Collaborative Study: Determination of Mycotoxins in Corn, Peanut Butter, and Wheat Flour Using Stable Isotope Dilution Assay (SIDA) and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

    PubMed

    Zhang, Kai; Schaab, Matthew R; Southwood, Gavin; Tor, Elizabeth R; Aston, Linda S; Song, Wenlu; Eitzer, Brian; Majumdar, Sanghamitra; Lapainis, Theodore; Mai, Huy; Tran, Kevin; El-Demerdash, Aref; Vega, Victor; Cai, Yanxuan; Wong, Jon W; Krynitsky, Alexandra J; Begley, Timothy H

    2017-08-23

    A collaborative study was conducted to evaluate stable isotope dilution assay (SIDA) and LC-MS/MS for the simultaneous determination of aflatoxins B 1 , B 2 , G 1 , and G 2 ; deoxynivalenol; fumonisins B 1 , B 2 , and B 3 ; ochratoxin A; HT-2 toxin; T-2 toxin; and zearalenone in foods. Samples were fortified with 12 13 C uniformly labeled mycotoxins ( 13 C-IS) corresponding to the native mycotoxins and extracted with acetonitrile/water (50:50 v/v), followed by centrifugation, filtration, and LC-MS/MS analysis. In addition to certified reference materials, the six participating laboratories analyzed corn, peanut butter, and wheat flour fortified with the 12 mycotoxins at concentrations ranging from 1.0 to 1000 ng/g. Using their available LC-MS/MS platform, each laboratory developed in-house instrumental conditions for analysis. The majority of recoveries ranged from 80 to 120% with relative standard derivations (RSDs) <20%. Greater than 90% of the average recoveries of the participating laboratories were in the range of 90-110%, with repeatability RSD r (within laboratory) < 10% and reproducibility RSD R (among laboratory) < 15%. All Z scores of the results of certified reference materials were between -2 and 2. Using 13 C-IS eliminated the need for matrix-matched calibration standards for quantitation, simplified sample preparation, and achieved simultaneous identification and quantitation of multiple mycotoxins in a simple LC-MS/MS procedure.

  3. LC-MS-Based Lipidomics and Automated Identification of Lipids Using the LipidBlast In-Silico MS/MS Library.

    PubMed

    Cajka, Tomas; Fiehn, Oliver

    2017-01-01

    This protocol describes the analysis, specifically the identification, of blood plasma lipids. Plasma lipids are extracted using methyl tert-butyl ether (MTBE), methanol, and water followed by separation and data acquisition of isolated lipids using reversed-phase liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry (RPLC-QTOFMS) operated in MS/MS mode. For lipid identification, acquired MS/MS spectra are converted to the mascot generic format (MGF) followed by library search using the in-silico MS/MS library LipidBlast. Using this approach, lipid classes, carbon-chain lengths, and degree of unsaturation of fatty-acid components are annotated.

  4. Metabolomics and Trace Element Analysis of Camel Tear by GC-MS and ICP-MS.

    PubMed

    Ahamad, Syed Rizwan; Raish, Mohammad; Yaqoob, Syed Hilal; Khan, Altaf; Shakeel, Faiyaz

    2017-06-01

    Camel tear metabolomics and elemental analysis are useful in getting the information regarding the components responsible for maintaining the protective system that allows living in the desert and dry regions. The aim of this study was to correlate that the camel tears can be used as artificial tears for the evaluation of dryness in the eye. Eye biomarkers of camel tears were analyzed by gas chromatography-mass spectroscopy (GC-MS) and inductively coupled plasma mass spectroscopy (ICP-MS). The major compounds detected in camel tears by GC-MS were alanine, valine, leucine, norvaline, glycine, cadaverine, urea, ribitol, sugars, and higher fatty acids like octadecanoic acid and hexadecanoic acid. GC-MS analysis of camel tears also finds several products of metabolites and its associated metabolic participants. ICP-MS analysis showed the presence of different concentration of elemental composition in the camel tears.

  5. Development of an LC-MS/MS method for studying migration characteristics of acetaldehyde in polyethylene terephthalate (PET)-packed mineral water.

    PubMed

    Baumjohann, Nina; Harms, Diedrich

    2015-01-01

    During storage, acetaldehyde migration from polyethylene terephthalate (PET) bottles can affect the quality of mineral water even in the low µg l(-1) range negatively, as it features a fruity or plastic-like off-flavour. For a sensitive and fast analysis of acetaldehyde in mineral water, a new analysis method of 2,4-dinitrophenylhydrazine (DNPH) derivatisation followed by HPLC-electrospray tandem mass spectrometry (ESI-MS/MS) was developed. Acetaldehyde was directly derivatised in the mineral water sample avoiding extraction and/or pre-concentration steps and then analysed by reversed-phase HPLC-ESI-MS/MS using multiple reaction monitoring mode (MRM). Along with method development, the optimum molar excess of DNPH in contrast to acetaldehyde was studied for the mineral water matrix, because no specific and robust data were yet available for this critical parameter. Best results were obtained by using a calibration via the derivatisation reaction. Without any analyte enrichment or extraction, an LOD of 0.5 µg l(-1) and an LOQ of 1.9 µg l(-1) were achieved. Using the developed method, mineral water samples packed in PET bottles from Germany were analysed and the correlation between the acetaldehyde concentration and other characteristics of the samples was evaluated illustrating the applicability of the method. Besides a relationship between bottle size and CO2 content of the mineral water and acetaldehyde migration, a correlation with acetaldehyde migration and the material composition of the bottle, e.g. recycled PET, was noted. Investigating the light influence on the acetaldehyde migration with a newly developed, reproducible light exposure setup, a significant increase of the acetaldehyde concentration in carbonated mineral water samples was observed.

  6. Cognitive rehabilitation and mindfulness in multiple sclerosis (REMIND-MS): a study protocol for a randomised controlled trial.

    PubMed

    Nauta, Ilse M; Speckens, Anne E M; Kessels, Roy P C; Geurts, Jeroen J G; de Groot, Vincent; Uitdehaag, Bernard M J; Fasotti, Luciano; de Jong, Brigit A

    2017-11-21

    Cognitive problems frequently occur in patients with multiple sclerosis (MS) and profoundly affect their quality of life. So far, the best cognitive treatment options for MS patients are a matter of debate. Therefore, this study aims to investigate the effectiveness of two promising non-pharmacological treatments: cognitive rehabilitation therapy (CRT) and mindfulness-based cognitive therapy (MBCT). Furthermore, this study aims to gain additional knowledge about the aetiology of cognitive problems among MS patients, since this may help to develop and guide effective cognitive treatments. In a dual-centre, single-blind randomised controlled trial (RCT), 120 MS patients will be randomised into one of three parallel groups: CRT, MBCT or enhanced treatment as usual (ETAU). Both CRT and MBCT consist of a structured 9-week program. ETAU consists of one appointment with an MS specialist nurse. Measurements will be performed at baseline, post-intervention and 6 months after the interventions. The primary outcome measure is the level of subjective cognitive complaints. Secondary outcome measures are objective cognitive function, functional brain network measures (using magnetoencephalography), psychological symptoms, well-being, quality of life and daily life functioning. To our knowledge, this will be the first RCT that investigates the effect of MBCT on cognitive function among MS patients. In addition, studying the effect of CRT on cognitive function may provide direction to the contradictory evidence that is currently available. This study will also provide information on changes in functional brain networks in relation to cognitive function. To conclude, this study may help to understand and treat cognitive problems among MS patients. This trial was prospectively registered at the Dutch Trial Registration (number NTR6459 , registered on 31 May 2017).

  7. Highly sensitive LC-MS/MS-ESI method for determination of phenelzine in human plasma and its application to a human pharmacokinetic study.

    PubMed

    Kallem, Raja Reddy; Jillela, Bhupathi; Ravula, Arun Reddy; Samala, Ramakrishna; Andy, Adinarayana; Ramesh, Mullangi; Rao, Jvln Seshagiri

    2016-06-01

    A selective, sensitive and rapid LC-MS/MS method has been developed and validated for quantification of the phenelzine (PZ) in 200μL of human plasma using hydroxyzine (HZ) as an internal standard (IS) as per regulatory guidelines. The sample preparation involved the derivatization of PZ using pentaflurobenzaldehyde followed by solid phase extraction process to extract PZ and HZ from human plasma. LC-MS/MS was operated under the multiple reaction-monitoring mode (MRM) using the electro spray ionization technique in positive ion mode and the transitions of m/z 305.1→105.1 and m/z 375.3→201.1 were used to measure the derivative of PZ and IS, respectively. The total run time was 3.5min and the elution of PZ and HZ occurred at 2.53, and 1.92min, respectively; this was achieved with a mobile phase consisting of 10mM ammonium acetate: acetonitrile (20:80, v/v) at a flow rate of 1.0mL/min on an Ace C18 column with a split ratio of 70:30. The developed method was validated in human plasma with a lower limit of quantitation 0.51ng/mL. A linear response function was established for the range of concentrations 0.51-25.2ng/mL (r>0.995) for PZ. The intra- and inter-day precision values met the acceptance criteria. PZ was stable in the battery of stability studies viz., stock solution, bench-top, auto-sampler, long-term and freeze/thaw cycles. The developed assay method was applied to an oral bioequivalence study in humans. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Evaluation of SDS depletion using an affinity spin column and IMS-MS detection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hengel, Shawna M.; Floyd, Erica A.; Baker, Erin Shammel

    2012-11-01

    While the use of detergents is necessary for a variety of protein isolation preparation protocols, often prior to mass spectral (MS) analysis, they are not compatible with MS analysis due to ion suppression and adduct formation. This manuscript describes optimization of detergent removal, using commercially available SDS depletion spin columns containing an affinity resin, providing for both increased protein recovery and thorough SDS removal. Ion mobility spectrometry coupled with mass spectrometry (IMS-MS) allowed for a concurrent analysis of both analyte and detergent. In the case of both proteins and peptides, higher detergent concentrations than previously reported provided an increase ofmore » sample recovery; however there was a limit as SDS was detected by IMS-MS at higher levels of SDS indicating incomplete detergent depletion. The results also suggest optimal conditions for SDS removal are dependent on the sample concentration. Overall, this study provides a useful guide for proteomic studies where SDS is required for efficient sample preparation.« less

  9. MEASUREMENT OF OXIDATIVE STRESS PARAMETERS USING LIQUID CHROMATOGRAPHY - TANDEM MASS SPECTROSCOPY (LC-MS/MS)

    EPA Science Inventory

    What is the study?
    An invited review article. Measurement of oxidative stress parameters using liquid chromatography-tandem mass spectroscopy (LC-MS/MS)
    Why was it done?
    Although oxidative stress is frequently cited as a cause of various adverse biological eff...

  10. Distinctive and Complementary MS2 Fragmentation Characteristics for Identification of Sulfated Sialylated N-Glycopeptides by nanoLC-MS/MS Workflow

    NASA Astrophysics Data System (ADS)

    Kuo, Chu-Wei; Guu, Shih-Yun; Khoo, Kay-Hooi

    2018-04-01

    High sensitivity identification of sulfated glycans carried on specific sites of glycoproteins is an important requisite for investigation of molecular recognition events involved in diverse biological processes. However, aiming for resolving site-specific glycosylation of sulfated glycopeptides by direct LC-MS2 sequencing is technically most challenging. Other than the usual limiting factors such as lower abundance and ionization efficiency compared to analysis of non-glycosylated peptides, confident identification of sulfated glycopeptides among the more abundant non-sulfated glycopeptides requires additional considerations in the selective enrichment and detection strategies. Metal oxide has been applied to enrich phosphopeptides and sialylated glycopeptides, but its use to capture sulfated glycopeptides has not been investigated. Likewise, various complementary MS2 fragmentation modes have yet to be tested against sialylated and non-sialylated sulfoglycopeptides due to limited appropriate sample availability. In this study, we have investigated the feasibility of sequencing tryptic sulfated N-glycopeptide and its MS2 fragmentation characteristics by first optimizing the enrichment methods to allow efficient LC-MS detection and MS2 analysis by a combination of CID, HCD, ETD, and EThcD on hybrid and tribrid Orbitrap instruments. Characteristic sulfated glyco-oxonium ions and direct loss of sulfite from precursors were detected as evidences of sulfate modification. It is anticipated that the technical advances demonstrated in this study would allow a feasible extension of our sulfoglycomic analysis to sulfoglycoproteomics. [Figure not available: see fulltext.

  11. Metabolic profiling of roots of liquorice (Glycyrrhiza glabra) from different geographical areas by ESI/MS/MS and determination of major metabolites by LC-ESI/MS and LC-ESI/MS/MS.

    PubMed

    Montoro, Paola; Maldini, Mariateresa; Russo, Mariateresa; Postorino, Santo; Piacente, Sonia; Pizza, Cosimo

    2011-02-20

    Liquid chromatography electrospray mass spectrometry (LC-ESI/MS) has been applied to the full characterization of saponins and phenolics in hydroalcoholic extracts of roots of liquorice (Glycyrrhiza glabra). Relative quantitative analyses of the samples with respect to the phenolic constituents and to a group of saponins related to glycyrrhizic acid were performed using LC-ESI/MS. For the saponin constituents, full scan LC-MS/MS fragmentation of the protonated (positive ion mode) or deprotonated (negative ion mode) molecular species generated diagnostic fragment ions that provided information concerning the triterpene skeleton and the number and nature of the substituents. On the basis of the specific fragmentation of glycyrrhizic acid, an LC-MS/MS method was developed in order to quantify the analyte in the liquorice root samples. Chinese G. glabra roots contained the highest levels of glycyrrhizic acid, followed by those from Italy (Calabria). Copyright © 2010 Elsevier B.V. All rights reserved.

  12. UPLC-MS-MS Method for the Determination of Vilazodone in Human Plasma: Application to a Pharmacokinetic Study.

    PubMed

    El-Bagary, Ramzia; Hashem, Hanaa; Fouad, Marwa; Tarek, Sally

    2016-09-01

    A sensitive, rapid and simple liquid chromatographic-electrospray ionization tandem mass spectrometric (LC-ESI-MS-MS) method was developed for the quantitative determination of vilazodone in human plasma and for the study of the pharmacokinetic behavior of vilazodone in healthy Egyptian volunteers. With escitalopram as internal standard (IS), liquid-liquid extraction was used for the purification and preconcentration of analytes from human plasma matrix using diethyl ether. The separation was performed on an Acquity UPLC BEH shield RP C18 column (1.7 µm, 2.1 × 150 mm). Isocratic elution was applied using methanol-0.2% formic acid (90:10, v/v). Detection was performed on a triple-quadrupole tandem mass spectrometer with multiple reaction monitoring mode via an electrospray ionization source at m/z 442.21 → 155.23 for vilazodone and m/z 325.14 → 109.2 for escitalopram. Linear calibration curves were obtained over the range of 1-200 ng/mL with the lower limit of quantification at 1 ng/mL. The intra- and inter-day precision showed relative standard deviation ≤3.3%. The total run time was 1.5 min. This method was successfully applied for clinical pharmacokinetic investigation, and a preliminary metabolic study was also carried out. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. High-Throughput Microbore UPLC-MS Metabolic Phenotyping of Urine for Large-Scale Epidemiology Studies.

    PubMed

    Gray, Nicola; Lewis, Matthew R; Plumb, Robert S; Wilson, Ian D; Nicholson, Jeremy K

    2015-06-05

    A new generation of metabolic phenotyping centers are being created to meet the increasing demands of personalized healthcare, and this has resulted in a major requirement for economical, high-throughput metabonomic analysis by liquid chromatography-mass spectrometry (LC-MS). Meeting these new demands represents an emerging bioanalytical problem that must be solved if metabolic phenotyping is to be successfully applied to large clinical and epidemiological sample sets. Ultraperformance (UP)LC-MS-based metabolic phenotyping, based on 2.1 mm i.d. LC columns, enables comprehensive metabolic phenotyping but, when employed for the analysis of thousands of samples, results in high solvent usage. The use of UPLC-MS employing 1 mm i.d. columns for metabolic phenotyping rather than the conventional 2.1 mm i.d. methodology shows that the resulting optimized microbore method provided equivalent or superior performance in terms of peak capacity, sensitivity, and robustness. On average, we also observed, when using the microbore scale separation, an increase in response of 2-3 fold over that obtained with the standard 2.1 mm scale method. When applied to the analysis of human urine, the 1 mm scale method showed no decline in performance over the course of 1000 analyses, illustrating that microbore UPLC-MS represents a viable alternative to conventional 2.1 mm i.d. formats for routine large-scale metabolic profiling studies while also resulting in a 75% reduction in solvent usage. The modest increase in sensitivity provided by this methodology also offers the potential to either reduce sample consumption or increase the number of metabolite features detected with confidence due to the increased signal-to-noise ratios obtained. Implementation of this miniaturized UPLC-MS method of metabolic phenotyping results in clear analytical, economic, and environmental benefits for large-scale metabolic profiling studies with similar or improved analytical performance compared to

  14. MassSieve: Panning MS/MS peptide data for proteins

    PubMed Central

    Slotta, Douglas J.; McFarland, Melinda A.; Markey, Sanford P.

    2010-01-01

    We present MassSieve, a Java-based platform for visualization and parsimony analysis of single and comparative LC-MS/MS database search engine results. The success of mass spectrometric peptide sequence assignment algorithms has led to the need for a tool to merge and evaluate the increasing data set sizes that result from LC-MS/MS-based shotgun proteomic experiments. MassSieve supports reports from multiple search engines with differing search characteristics, which can increase peptide sequence coverage and/or identify conflicting or ambiguous spectral assignments. PMID:20564260

  15. Metabolism of the new psychoactive substances N,N-diallyltryptamine (DALT) and 5-methoxy-DALT and their detectability in urine by GC-MS, LC-MSn, and LC-HR-MS-MS.

    PubMed

    Michely, Julian A; Helfer, Andreas G; Brandt, Simon D; Meyer, Markus R; Maurer, Hans H

    2015-10-01

    N,N-Diallyltryptamine (DALT) and 5-methoxy-DALT (5-MeO-DALT) are synthetic tryptamine derivatives commonly referred to as so-called new psychoactive substances (NPS). They have psychoactive effects that may be similar to those of other tryptamine derivatives. The objectives of this work were to study the metabolic fate and detectability, in urine, of DALT and 5-MeO-DALT. For metabolism studies, rat urine obtained after high-dose administration was prepared by precipitation and analyzed by liquid chromatography-high-resolution mass spectrometry (LC-HR-MS-MS). On the basis of the metabolites identified, several aromatic and aliphatic hydroxylations, N-dealkylation, N-oxidation, and combinations thereof are proposed as the main metabolic pathways for both compounds. O-Demethylation of 5-MeO-DALT was also observed, in addition to extensive glucuronidation or sulfation of both compounds after phase I transformation. The cytochrome P450 (CYP) isoenzymes predominantly involved in DALT metabolism were CYP2C19, CYP2D6, and CYP3A4; those mainly involved in 5-MeO-DALT metabolism were CYP1A2, CYP2C19, CYP2D6, and CYP3A4. For detectability studies, rat urine was screened by GC-MS, LC-MS(n), and LC-HR-MS-MS after administration of low doses. LC-MS(n) and LC-HR-MS-MS were deemed suitable for monitoring consumption of both compounds. The most abundant targets were a ring hydroxy metabolite of DALT, the N,O-bis-dealkyl metabolite of 5-MeO-DALT, and their glucuronides. GC-MS enabled screening of DALT by use of its main metabolites only.

  16. Application of LC/MS/MS Techniques to Development of US ...

    EPA Pesticide Factsheets

    This presentation will describe the U.S. EPA’s drinking water and ambient water method development program in relation to the process employed and the typical challenges encountered in developing standardized LC/MS/MS methods for chemicals of emerging concern. The EPA’s Drinking Water Contaminant Candidate List and Unregulated Contaminant Monitoring Regulations, which are the driving forces behind drinking water method development, will be introduced. Three drinking water LC/MS/MS methods (Methods 537, 544 and a new method for nonylphenol) and two ambient water LC/MS/MS methods for cyanotoxins will be described that highlight some of the challenges encountered during development of these methods. This presentation will provide the audience with basic understanding of EPA's drinking water method development program and an introduction to two new ambient water EPA methods.

  17. Mycotoxin Analysis of Human Urine by LC-MS/MS: A Comparative Extraction Study

    PubMed Central

    Escrivá, Laura; Font, Guillermina

    2017-01-01

    The lower mycotoxin levels detected in urine make the development of sensitive and accurate analytical methods essential. Three extraction methods, namely salting-out liquid–liquid extraction (SALLE), miniQuEChERS (quick, easy, cheap, effective, rugged, and safe), and dispersive liquid–liquid microextraction (DLLME), were evaluated and compared based on analytical parameters for the quantitative LC-MS/MS measurement of 11 mycotoxins (AFB1, AFB2, AFG1, AFG2, OTA, ZEA, BEA, EN A, EN B, EN A1 and EN B1) in human urine. DLLME was selected as the most appropriate methodology, as it produced better validation results for recovery (79–113%), reproducibility (RSDs < 12%), and repeatability (RSDs < 15%) than miniQuEChERS (71–109%, RSDs <14% and <24%, respectively) and SALLE (70–108%, RSDs < 14% and < 24%, respectively). Moreover, the lowest detection (LODS) and quantitation limits (LOQS) were achieved with DLLME (LODs: 0.005–2 μg L−1, LOQs: 0.1–4 μg L−1). DLLME methodology was used for the analysis of 10 real urine samples from healthy volunteers showing the presence of ENs B, B1 and A1 at low concentrations. PMID:29048356

  18. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) and dried blood spot sampling applied to pharmacokinetics studies in animals: Correlation of classic and block design.

    PubMed

    Baldo, Matías N; Angeli, Emmanuel; Gareis, Natalia C; Hunzicker, Gabriel A; Murguía, Marcelo C; Ortega, Hugo H; Hein, Gustavo J

    2018-04-01

    A relative bioavailability study (RBA) of two phenytoin (PHT) formulations was conducted in rabbits, in order to compare the results obtained from different matrices (plasma and blood from dried blood spot (DBS) sampling) and different experimental designs (classic and block). The method was developed by liquid chromatography tandem-mass spectrometry (LC-MS/MS) in plasma and blood samples. The different sample preparation techniques, plasma protein precipitation and DBS, were validated according to international requirements. The analytical method was validated with ranges 0.20-50.80 and 0.12-20.32 µg ml -1 , r > 0.999 for plasma and blood, respectively. Accuracy and precision were within acceptance criteria for bioanalytical assay validation (< 15 for bias and CV% and < 20 for limit of quantification (LOQ)). PHT showed long-term stability, both for plasma and blood, and under refrigerated and room temperature conditions. Haematocrit values were measured during the validation process and RBA study. Finally, the pharmacokinetic parameters (C max , T max and AUC 0-t ) obtained from the RBA study were tested. Results were highly comparable for matrices and experimental designs. A matrix correlation higher than 0.975 and a ratio of (PHT blood) = 1.158 (PHT plasma) were obtained. The results obtained herein show that the use of classic experimental design and DBS sampling for animal pharmacokinetic studies should be encouraged as they could help to prevent the use of a large number of animals and also animal euthanasia. Finally, the combination of DBS sampling with LC-MS/MS technology showed to be an excellent tool not only for therapeutic drug monitoring but also for RBA studies.

  19. Advantages of automation in plasma sample preparation prior to HPLC/MS/MS quantification: application to the determination of cilazapril and cilazaprilat in a bioequivalence study.

    PubMed

    Kolocouri, Filomila; Dotsikas, Yannis; Apostolou, Constantinos; Kousoulos, Constantinos; Soumelas, Georgios-Stefanos; Loukas, Yannis L

    2011-01-01

    An HPLC/MS/MS method characterized by complete automation and high throughput was developed for the determination of cilazapril and its active metabolite cilazaprilat in human plasma. All sample preparation and analysis steps were performed by using 2.2 mL 96 deep-well plates, while robotic liquid handling workstations were utilized for all liquid transfer steps, including liquid-liquid extraction. The whole procedure was very fast compared to a manual procedure with vials and no automation. The method also had a very short chromatographic run time of 1.5 min. Sample analysis was performed by RP-HPLC/MS/MS with positive electrospray ionization using multiple reaction monitoring. The calibration curve was linear in the range of 0.500-300 and 0.250-150 ng/mL for cilazapril and cilazaprilat, respectively. The proposed method was fully validated and proved to be selective, accurate, precise, reproducible, and suitable for the determination of cilazapril and cilazaprilat in human plasma. Therefore, it was applied to a bioequivalence study after per os administration of 2.5 mg tablet formulations of cilazapril.

  20. The co-occurrence of multiple sclerosis and type 1 diabetes: shared aetiologic features and clinical implication for MS aetiology.

    PubMed

    Tettey, Prudence; Simpson, Steve; Taylor, Bruce V; van der Mei, Ingrid A F

    2015-01-15

    We reviewed the evidence for the co-occurrence of type 1 diabetes mellitus (T1D) and multiple sclerosis (MS), and assessed the clinical significance of this association and the shared aetiological features of the two diseases. T1D and MS contribute considerably to the burden of autoimmune diseases in young adults. The co-occurrence of MS and T1D has been reported by a number of studies, suggesting that the two conditions share one or more aetiological components. Both conditions have been associated with distinct human leukocyte antigen (HLA) haplotypes but share a number of similarities in clinical, epidemiological and immunological features, leading to suggestions of possible common mechanisms of development. While underlying genetic factors may be important for the co-occurrence of both conditions, some evidence suggests that environmental factors such as vitamin D deficiency may also modulate an individual's risk for the development of both conditions. Evidence on whether the co-occurrence of the two autoimmune conditions will affect the disease course and severity of MS is merely absent. Further studies need to be conducted to ascertain whether the neuropathology associated with T1D might influence the disease course and contribute to the severity of MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. The First MS-Cleavable, Photo-Thiol-Reactive Cross-Linker for Protein Structural Studies

    NASA Astrophysics Data System (ADS)

    Iacobucci, Claudio; Piotrowski, Christine; Rehkamp, Anne; Ihling, Christian H.; Sinz, Andrea

    2018-04-01

    Cleavable cross-linkers are gaining increasing importance for chemical cross-linking/mass spectrometry (MS) as they permit a reliable and automated data analysis in structural studies of proteins and protein assemblies. Here, we introduce 1,3-diallylurea (DAU) as the first CID-MS/MS-cleavable, photo-thiol-reactive cross-linker. DAU is a commercially available, inexpensive reagent that efficiently undergoes an anti-Markovnikov hydrothiolation with cysteine residues in the presence of a radical initiator upon UV-A irradiation. Radical cysteine cross-linking proceeds via an orthogonal "click reaction" and yields stable alkyl sulfide products. DAU reacts at physiological pH and cross-linking reactions with peptides, and proteins can be performed at temperatures as low as 4 °C. The central urea bond is efficiently cleaved upon collisional activation during tandem MS experiments generating characteristic product ions. This improves the reliability of automated cross-link identification. Different radical initiators have been screened for the cross-linking reaction of DAU using the thiol-containing compounds cysteine and glutathione. Our concept has also been exemplified for the biologically relevant proteins bMunc13-2 and retinal guanylyl cyclase-activating protein-2. [Figure not available: see fulltext.

  2. Characterizing fluorotelomer and polyfluoroalkyl substances in new and aged fluorotelomer-based polymers for degradation studies with GC/MS and LC/MS/MS.

    PubMed

    Washington, John W; Naile, Jonathan E; Jenkins, Thomas M; Lynch, David G

    2014-05-20

    Fluorotelomer-based polymers (FTPs), the dominant product of the fluorotelomer industry, are antistaining and antiwetting agents that permeate the products and surfaces of modern society. However, the degree to which these materials expose humans and the environment to fluorotelomer and perfluorinated compounds, including recalcitrant and toxic compounds such as perfluorooctanoic acid (PFOA), is ill-defined. The design intent of FTPs, to minimize interaction with other substances, including solvents, heretofore has stymied efforts to develop robust methods to characterize the content of monomers and associated compounds of new commercial FTPs, as well as commercial FTPs that have been aged in environmental media for degradation testing. Here we show that FTPs can be exhausted of these compounds and quantitated by (i) drying the FTP on a suitable substrate at elevated temperature to achieve low, constant monomer concentrations; (ii) serial extraction with MTBE for fluorotelomer-monomer analysis by GC/MS in PCI mode; followed by (iii) serial extraction with 90/10 ACN/H2O for polyfluorocompound analysis by LC/MS/MS in negative ESI mode. This approach yields exhaustive, internally consistent accounting of monomers and associated compounds for FTPs, either alone or in a soil matrix (representing an environmental medium), for both new and simulated-aged FTPs to allow degradation testing, and for fluorinated compounds at least as long as C12.

  3. A validated UPLC-MS/MS method for the analysis of linezolid and a novel oxazolidinone derivative (PH027) in plasma and its application to tissue distribution study in rabbits.

    PubMed

    Hedaya, Mohsen A; Thomas, Vidhya; Abdel-Hamid, Mohamed E; Kehinde, Elijah O; Phillips, Oludotun A

    2017-01-01

    Linezolid is the first approved oxazolidinone antibacterial agent, whereas PH027 is a novel compound of the same class that exhibits good in vitro antibacterial activity. The objective of this study was to develop an UPLC-MS/MS assay for the analysis of linezolid and PH027 in plasma and to apply the method for comparative pharmacokinetic and tissue distribution studies of both compounds. Plasma samples and calibrators were extracted with diethyl ether after addition of the internal standard solution. After evaporation of the ether layer, the residue was reconstituted in mobile phase and injected into UPLC-MS/MS. The mobile phase consisted of 2mM ammonium acetate buffer solution and acetonitrile (70:30) at a flow rate of 0.2ml/min. Separation was achieved using UPLC BEH C 18 column, and quantitative determination of the analytes was performed using multiple-reaction monitoring (MRM) scanning mode. The method was validated by analyzing quality control tissue homogenate samples, and was applied to analyze tissue homogenate samples obtained following IV injections of linezolid and PH027 in rabbits. The developed UPLC-MS/MS method was linear in the concentration range of 50-5000ng/ml. Validation of the method proved that the method's precision, selectivity and stability were all within the acceptable limits. Linezolid and PH027 concentrations were accurately determined in the quality control tissue homogenate samples, and analysis of samples obtained following IV administration of the two compounds showed that the tissue to plasma concentration ratio of PH027 was higher than that of linezolid probably due to its higher lipophilicity. The developed UPLC-MS/MS method for the analysis of linezolid and PH027 in rabbit's plasma can accurately determine the concentrations of these compounds in different tissues. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. LC-MS/MS-based approach for obtaining exposure estimates of metabolites in early clinical trials using radioactive metabolites as reference standards.

    PubMed

    Zhang, Donglu; Raghavan, Nirmala; Chando, Theodore; Gambardella, Janice; Fu, Yunlin; Zhang, Duxi; Unger, Steve E; Humphreys, W Griffith

    2007-12-01

    An LC-MS/MS-based approach that employs authentic radioactive metabolites as reference standards was developed to estimate metabolite exposures in early drug development studies. This method is useful to estimate metabolite levels in studies done with non-radiolabeled compounds where metabolite standards are not available to allow standard LC-MS/MS assay development. A metabolite mixture obtained from an in vivo source treated with a radiolabeled compound was partially purified, quantified, and spiked into human plasma to provide metabolite standard curves. Metabolites were analyzed by LC-MS/MS using the specific mass transitions and an internal standard. The metabolite concentrations determined by this approach were found to be comparable to those determined by valid LC-MS/MS assays. This approach does not requires synthesis of authentic metabolites or the knowledge of exact structures of metabolites, and therefore should provide a useful method to obtain early estimates of circulating metabolites in early clinical or toxicological studies.

  5. Analysis of poly-beta-hydroxybutyrate in environmental samples by GC-MS/MS.

    PubMed

    Elhottová, D; Tríska, J; Petersen, S O; Santrůcková, H

    2000-05-01

    Application of gas chromatography-mass spectrometry (GC-MS) can significantly improve trace analyses of compounds in complex matrices from natural environments compared to gas chromatography only. A GC-MS/MS technique for determination of poly-beta-hydroxybutyrate (PHB), a bacterial storage compound, has been developed and used for analysis of two soils stored for up to 319 d, fresh samples of sewage sludge, as well as a pure culture of Bacillus megaterium. Specific derivatization of beta-hydroxybutyrate (3-OH C4:0) PHB monomer units by N-tert-butyl-dimethylsilyl-N-methyltrifluoracetamide (MTBSTFA) improved chromatographic and mass spectrometric properties of the analyte. The diagnostic fragmentation scheme of the derivates tert-butyldimethylsilyl ester and ether of beta-hydroxybutyric acid (MTBSTFA-HB) essential for the PHB identification was shown. The ion trap MS was used, therefore the scan gave the best sensitivity and with MS/MS the noise decreased, so the S/N was better and also with second fragmentation the amount of ions increased compared to SIM. The detection limit for MTBSTFA-HB by GC-MS/MS was about 10(-13) g microL(-1) of injected volume, while by GC (FID) and GC-MS (scan) it was around 10(-10) g microL(-1) of injected volume. Sensitivity of GC-MS/MS measurements of PHB in arable soil and activated sludge samples was down to 10 pg of PHB g(-1) dry matter. Comparison of MTBSTFA-HB detection in natural soil sample by GC (FID), GC-MS (scan) and by GC-MS/MS demonstrated potentials and limitations of the individual measurement techniques.

  6. Quantitation of 25-hydroxyvitamin D in dried blood spots by 2D LC-MS/MS without derivatization and correlation with serum in adult and pediatric studies.

    PubMed

    Jensen, Berit P; Saraf, Rajneeta; Ma, Jing; Berry, Sarah; Grant, Cameron C; Camargo, Carlos A; Sies, Christiaan W

    2018-06-01

    Demand for measurement of 25-hydroxyvitamin D (25OHD) is growing and dried blood spot (DBS) sampling is attractive as samples are easier to collect, transport and store. A 2D LC-MS/MS assay without derivatization was developed. DBS punches (3.2 mm) were ultrasonicated with d 6 -25OHD 3 in 70% methanol followed by hexane extraction, dry-down and reconstitution. The assay was validated and applied to two studies comparing whole blood adult DBS with serum samples (n = 40) and neonatal whole blood DBS with cord serum samples (n = 80). The assay was validated in whole blood DBS over the range 13-106 nmol/L 25OHD 3 and 11-91 nmol/L 25OHD 2 with a limit of detection of 3 nmol/L. Intra- and inter-day imprecision was <13% CV and bias <12%. The assay had high recovery and minimal matrix effects. Triplicate DBS study samples had a mean CV of ≤13% for 25OHD 3. No 25OHD 2 was detected. DBS calculated serum 25OHD 3 concentrations correlated strongly with serum concentrations in the adult DBS/serum study (r = 0.94) and moderately in the neonatal DBS/cord serum study (r = 0.69). Direct quantitation of 25OHD in DBS by 2D LC-MS/MS without derivatization was found to be an alternative to serum quantitation applicable to clinical research studies on adult DBS samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Development of Chiral LC-MS Methods for small Molecules and Their Applications in the Analysis of Enantiomeric Composition and Pharmacokinetic Studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Desai, Meera Jay

    was then used to simultaneously separate all 19 native amino acids enantiomerically in less than 20 minutes, making it suitable for complex biological analysis. The previously developed amino acid method was then used to enantiomerically separate theanine, a free amino acid found in tea leaves. Native theanine was found to have lower limits of detection and better sensitivity over derivatized theanine samples. The native theanine method was then used to determine the enantiomeric composition of six commercially available L-theanine products. Five out of the six samples were found to be a racemic mixture of both D- and L-theanine. Concern over the efficacy of these theanine products led to our final study evaluating the pharmacokinetics and pharmacodynamics of theanine in rats using LC-ESI/MS. Rats were administered D-, L, and QL-theanine both orally and intra-peritoneally. Oral administration data demonstrated that intestinal absorption of L-theanine was greater than that of D-theanine, while i.p. data showed equal plasma uptake of both isomers. This suggested a possible competitive binding effect with respect to gut absorption. Additionally, it was found that regardless of administration method, the presence of the other enantiomer always decreased overall theanine plasma concentration. This indicated that D- and L- theanine exhibit competitive binding with respect to urinary reabsorption as well. The large quantities of D-theanine detected in the urine suggested that D-themine was eliminated with minimal metabolism, while L-theanine was preferentially reabsorbed and metabolized to ethylamine. Clearly, the metabolic fate of racemic theanine and its individual enantiomers was quite different, placing into doubt the utility of the commercial theanine products.« less

  8. [Simultaneous determination of repaglinide and pravastatin sodium in rat plasma by LC-ms/MS and its application on pharmacokinetic interactions study].

    PubMed

    Ma, Yan-Rong; Zhou, Yan; Zhang, Guo-Qiang; Rao, Zhi; Huang, Jing; Wei, Yu-hui; Wu, Xin-An

    2014-01-01

    The study aims to establish a method for simultaneous determination of repaglinide and pravastatin sodium in rat plasma by LC-MS/MS and to study its pharmacokinetic interactions. Eighteen male SD rats were divided into repaglinide group, pravastatin sodium group and co-administration group. Blood samples were collected at different times after oral administration. Repaglinide and pravastatin sodium in rat plasma were separated by Agilent HC-C18 with the mobile phase consisting of methanol-0.1% formic acid (80 : 20). Detection and quantification were performed by using ESI-MS. The detector was operated in selected Reaction-monitoring mode at m/z 453.3-->230.1 for repaglinide, m/z 447.2-->327.4 for pravastatin sodium and m/z 285.1-->192.9 for diazepam as the internal standard. The calibration curve obtained was linear (R2>0.99) over the concentration range of 9.77-10,000 ng.mL-1 for repaglinide and 4.88-625 ng.mL-1 for pravastatin sodium. Compared with the single administration group, Cmax and AUC0-6h of repaglinide increased significantly (P<0.05) and tmax of pravastatin sodium prolonged (P<0.05) in co-administration group. The method is found to be simple, sensitive and accurate for determining the concentration of repaglinide and pravastatin sodium in rat plasma. There exists pharmacokinetic interactions in the co-administration of repaglinide and pravastatin sodium.

  9. A framework for measurement and harmonization of pediatric multiple sclerosis etiologic research studies: The Pediatric MS Tool-Kit.

    PubMed

    Magalhaes, Sandra; Banwell, Brenda; Bar-Or, Amit; Fortier, Isabel; Hanwell, Heather E; Lim, Ming; Matt, Georg E; Neuteboom, Rinze F; O'Riordan, David L; Schneider, Paul K; Pugliatti, Maura; Shatenstein, Bryna; Tansey, Catherine M; Wassmer, Evangeline; Wolfson, Christina

    2018-06-01

    While studying the etiology of multiple sclerosis (MS) in children has several methodological advantages over studying etiology in adults, studies are limited by small sample sizes. Using a rigorous methodological process, we developed the Pediatric MS Tool-Kit, a measurement framework that includes a minimal set of core variables to assess etiological risk factors. We solicited input from the International Pediatric MS Study Group to select three risk factors: environmental tobacco smoke (ETS) exposure, sun exposure, and vitamin D intake. To develop the Tool-Kit, we used a Delphi study involving a working group of epidemiologists, neurologists, and content experts from North America and Europe. The Tool-Kit includes six core variables to measure ETS, six to measure sun exposure, and six to measure vitamin D intake. The Tool-Kit can be accessed online ( www.maelstrom-research.org/mica/network/tool-kit ). The goals of the Tool-Kit are to enhance exposure measurement in newly designed pediatric MS studies and comparability of results across studies, and in the longer term to facilitate harmonization of studies, a methodological approach that can be used to circumvent issues of small sample sizes. We believe the Tool-Kit will prove to be a valuable resource to guide pediatric MS researchers in developing study-specific questionnaire.

  10. Comparisons between youth of a parent with MS and a control group on adjustment, caregiving, attachment and family functioning.

    PubMed

    Pakenham, K I; Cox, S

    2013-01-01

    Few studies have examined the effects of parental MS on children, and those that have suffered from numerous methodological weaknesses, some of which are addressed in this study. This study investigated the effects of parental MS on children by comparing youth of a parent with MS to youth who have no family member with a serious health condition on adjustment outcomes, caregiving, attachment and family functioning. A questionnaire survey methodology was used. Measures included youth somatisation, health, pro-social behaviour, behavioural-social difficulties, caregiving, attachment and family functioning. A total of 126 youth of a parent with MS were recruited from MS Societies in Australia and, were matched one-to-one with youth who had no family member with a health condition drawn from a large community sample. Comparisons showed that youth of a parent with MS did not differ on any of the outcomes except for peer relationship problems: adolescent youth of a parent with MS reported lower peer relationship problems than control adolescents. Overall, results did not support prior research findings suggesting adverse impacts of parental MS on youth.

  11. [Simultaneous determination of formononetin, calycosin and isorhamnetin from Astragalus mongholicus in rat plasma by LC-MS/MS and application to pharmacokinetic study].

    PubMed

    Lin, Qing; Li, Yuan; Tan, Xiao-Mei; Yao, Xiang-Chao

    2013-04-01

    To establish a method to determine the concentration of formononetin, calycosin and isorhamnetin from Astragalus mongholicus in rats' plasma using LC-MS/MS and calculate their pharmacokinetic parameters. The contents of formononetin, calycosin and isorhamnetin in plasma were detected before and 24 h after 10 rats were treated with 10 g/kg Astragalus mongholicus. Rutin was used as internal standard. Agilent 1 200 HPLC system with Alltima C18 (150 mm x 2.1 mm, 5 microm) was used. Mobile phase was methanol-water solution with gradient elute at a flow rate of 0.3 mL/min. The column temperature was 40 degrees C. The LC-MS/ MS system was operated using an electrospray ionization probe in negative ion mode; Scan mode: multiple reaction ion monitoring (MRM) mode. The ion of monitor: m/z 267.0 --> 251.9 for formononetin, m/z 283.1 --> 268.2 for calycosin, m/z 315.4 --> 300.1 for isorhamnetin and m/z 609.4 --> 300.1 for rutin (internal standard), respectively. The linear range of formononetin, calycosin and isorhamnetin was 5 - 1 000 (r = 0.9996), 3.91 - 500 (r = 0.9989) and 0.5 - 100 ng/mL (r = 0.9992), respectively. The lowest limit of quantification (LLOQ) of formononetin, calycosin and isorhamnetin was 0.625, 0.5 and 0.1 ng/mL, respectively. The pharmacokinetic parameter, t(1/2beta), of formononetin, calycosin and isorhamnetin was (10.43 +/- 2.94), (6.91 +/- 1.33) and (5.07 +/- 1.21) h, respectively. The C(max) of formononetin, calycosin and isorhamnetin was (398.5 +/- 103.7), (138.7 +/- 32.8) and (58.3 +/- 14.5) ng/mL, respectively. The AUC(0 -> 12h), of formononetin, calycosin and isorhamnetin was (1238.8 +/- 311.3), (669.5 +/- 159.7) and (274.1 +/- 83.9)ng x h/mL, respectively. A sensitive, accuracy and suitable LC-MS/MS method for determination of formononetin, calycosin and isorhamnetin is developed and successfully applied to the pharmacokinetic study of 10 g/kg Astragalus mongholicus after oral administration in rats.

  12. MS/MS studies on the selective on-line detection of sesquiterpenes using a Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS)

    NASA Astrophysics Data System (ADS)

    Rimetz-Planchon, J.; Dhooghe, F.; Schoon, N.; Vanhaecke, F.; Amelynck, C.

    2011-04-01

    A Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS) was used to investigate the feasibility of selective on-line detection of a series of seven sesquiterpenes (SQTs). These SQTs were chemically ionized by either H3O+ or NO+ reagent ions in the FA, resulting among others in protonated SQT and SQT molecular ions, respectively. These and other Chemical Ionization (CI) product ions were subsequently subjected to dissociation by collisions with Ar atoms in the collision cell of the tandem mass spectrometer. The fragmentation spectra show similarities with mass spectra obtained for these compounds with other instruments such as a Proton Transfer Reaction-Linear Ion Trap (PTR-LIT), a Proton Transfer Reaction-Mass Spectrometer (PTR-MS), a Triple Quadrupole-Mass Spectrometer (QqQ-MS) and a Selected Ion Flow Tube-Mass Spectrometer (SIFT-MS). Fragmentation of protonated SQT is characterized by fragment ions at the same masses but with different intensities for the individual SQT. Distinction of SQTs is based on well-chosen intensity ratios and collision energies. The fragmentation patterns of SQT molecular ions show specific fragment ion tracers at m/z 119, m/z162, m/z 137 and m/z 131 for α-cedrene, δ-neoclovene, isolongifolene and α-humulene, respectively. Consequently, chemical ionization of SQT by NO+, followed by MS/MS of SQT+ seems to open a way for selective quantification of SQTs in mixtures.

  13. Staphylococcus aureus methicillin resistance detected by HPLC-MS/MS targeted metabolic profiling.

    PubMed

    Schelli, Katie; Rutowski, Joshua; Roubidoux, Julia; Zhu, Jiangjiang

    2017-03-15

    Recently, novel bioanalytical methods, such as NMR and mass spectrometry based metabolomics approaches, have started to show promise in providing rapid, sensitive and reproducible detection of Staphylococcus aureus antibiotic resistance. Here we performed a proof-of-concept study focused on the application of HPLC-MS/MS based targeted metabolic profiling for detecting and monitoring the bacterial metabolic profile changes in response to sub-lethal levels of methicillin exposure. One hundred seventy-seven targeted metabolites from over 20 metabolic pathways were specifically screened and one hundred and thirty metabolites from in vitro bacterial tests were confidently detected from both methicillin susceptible and methicillin resistant Staphylococcus aureus (MSSA and MRSA, respectively). The metabolic profiles can be used to distinguish the isogenic pairs of MSSA strains from MRSA strains, without or with sub-lethal levels of methicillin exposure. In addition, better separation between MSSA and MRSA strains can be achieved in the latter case using principal component analysis (PCA). Metabolite data from isogenic pairs of MSSA and MRSA strains were further compared without and with sub-lethal levels of methicillin exposure, with metabolic pathway analyses additionally performed. Both analyses suggested that the metabolic activities of MSSA strains were more susceptible to the perturbation of the sub-lethal levels of methicillin exposure compared to the MRSA strains. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Biodiesel production from microalgal isolates of southern Pakistan and quantification of FAMEs by GC-MS/MS analysis

    PubMed Central

    2012-01-01

    Background Microalgae have attracted major interest as a sustainable source for biodiesel production on commercial scale. This paper describes the screening of six microalgal species, Scenedesmus quadricauda, Scenedesmus acuminatus, Nannochloropsis sp., Anabaena sp., Chlorella sp. and Oscillatoria sp., isolated from fresh and marine water resources of southern Pakistan for biodiesel production and the GC-MS/MS analysis of their fatty acid methyl esters (FAMEs). Results Growth rate, biomass productivity and oil content of each algal species have been investigated under autotrophic condition. Biodiesel was produced from algal oil by acid catalyzed transesterification reaction and resulting fatty acid methyl esters (FAMEs) content was analyzed by GC/MS. Fatty acid profiling of the biodiesel, obtained from various microalgal oils showed high content of C-16:0, C-18:0, cis-Δ9C-18:1, cis-Δ11C-18:1 (except Scenedesmus quadricauda) and 10-hydroxyoctadecanoic (except Scenedesmus acuminatus). Absolute amount of C-14:0, C-16:0 and C-18:0 by a validated GC-MS/MS method were found to be 1.5-1.7, 15.0-42.5 and 4.2-18.4 mg/g, respectively, in biodiesel obtained from various microalgal oils. Biodiesel was also characterized in terms of cetane number, kinematic viscosity, density and higher heating value and compared with the standard values. Conclusion Six microalgae of local origin were screened for biodiesel production. A method for absolute quantification of three important saturated fatty acid methyl esters (C-14, C-16 and C-18) by gas chromatography-tandem mass spectrometry (GC-MS/MS), using multiple reactions monitoring (MRM) mode, was employed for the identification and quantification of biodiesels obtained from various microalgal oils. The results suggested that locally found microalgae can be sustainably harvested for the production of biodiesel. This offers the tremendous economic opportunity for an energy-deficient nation. PMID:23216896

  15. Gaussian and linear deconvolution of LC-MS/MS chromatograms of the eight aminobutyric acid isomers

    PubMed Central

    Vemula, Harika; Kitase, Yukiko; Ayon, Navid J.; Bonewald, Lynda; Gutheil, William G.

    2016-01-01

    Isomeric molecules present a challenge for analytical resolution and quantification, even with MS-based detection. The eight-aminobutyric acid (ABA) isomers are of interest for their various biological activities, particularly γ-aminobutyric acid (GABA) and the d- and l-isomers of β-aminoisobutyric acid (β-AIBA; BAIBA). This study aimed to investigate LC-MS/MS-based resolution of these ABA isomers as their Marfey's (Mar) reagent derivatives. HPLC was able to separate three Mar-ABA isomers l-β-ABA (l-BABA), and l- and d-α-ABA (AABA) completely, with three isomers (GABA, and d/l-BAIBA) in one chromatographic cluster, and two isomers (α-AIBA (AAIBA) and d-BABA) in a second cluster. Partially separated cluster components were deconvoluted using Gaussian peak fitting except for GABA and d-BAIBA. MS/MS detection of Marfey's derivatized ABA isomers provided six MS/MS fragments, with substantially different intensity profiles between structural isomers. This allowed linear deconvolution of ABA isomer peaks. Combining HPLC separation with linear and Gaussian deconvolution allowed resolution of all eight ABA isomers. Application to human serum found a substantial level of l-AABA (13 μM), an intermediate level of l-BAIBA (0.8 μM), and low but detectable levels (<0.2 μM) of GABA, l-BABA, AAIBA, d-BAIBA, and d-AABA. This approach should be useful for LC-MS/MS deconvolution of other challenging groups of isomeric molecules. PMID:27771391

  16. Rapid method for the measurement of circulating thyroid hormones in low volumes of teleost fish plasma by LC-ESI/MS/MS

    PubMed Central

    Noyes, Pamela D.; Lema, Sean C.; Roberts, Simon C.; Cooper, Ellen M.

    2014-01-01

    Thyroid hormones are critical regulators of normal development and physiological functioning in all vertebrates. Radioimmunoassay (RIA) approaches have been the method of choice for measuring circulating levels of thyroid hormones in vertebrates. While sensitive, RIA-based approaches only allow for a single analyte measurement per assay, can lack concordance across platforms and laboratories, and can be prone to analytical interferences especially when used with fish plasma. Ongoing advances in liquid chromatography tandem mass spectrometry (LC/MS/MS) have led to substantial decreases in detection limits for thyroid hormones and other biomolecules in complex matrices, including human plasma. Despite these advances, current analytical approaches do not allow for the measurement of native thyroid hormone in teleost fish plasma by mass spectrometry and continue to rely on immunoassay. In this study, we developed a new method that allows for the rapid extraction and simultaneous measurement of total T4 (TT4) and total T3 (TT3) in low volumes (50 μL) of fish plasma by LC/MS/MS. Methods were optimized initially in plasma from rainbow trout (Oncorhynchus mykiss) and applied to plasma from other teleost fishes, including fathead minnows (Pimephales promelas), mummichogs (Fundulus heteroclitus), sockeye salmon (Oncorhynchus nerka), and coho salmon (Oncorhynchus kisutch). Validation of method performance with T4- and T3-spiked rainbow trout plasma at 2 and 4 ng/mL produced mean recoveries ranging from 82 to 95 % and 97 to 105 %, respectively. Recovery of 13C12-T4 internal standard in plasma extractions was: 99±1.8 % in rainbow trout, 85±11 % in fathead minnow, 73±5.0 % in mummichog, 73±1.7 % in sockeye salmon, and 80±8.4 % in coho salmon. While absolute levels of thyroid hormones measured in identical plasma samples by LC/MS/MS and RIA varied depending on the assay used, T4/T3 ratios were generally consistent across both techniques. Less variability was measured among

  17. Assessing fracture risk in people with MS: a service development study comparing three fracture risk scoring systems

    PubMed Central

    Dobson, Ruth; Leddy, Sara Geraldine; Gangadharan, Sunay; Giovannoni, Gavin

    2013-01-01

    Objectives Suboptimal bone health is increasingly recognised as an important cause of morbidity. Multiple sclerosis (MS) has been consistently associated with an increased risk of osteoporosis and fracture. Various fracture risk screening tools have been developed, two of which are in routine use and a further one is MS-specific. We set out to compare the results obtained by these in the MS clinic population. Design This was a service development study. The 10-year risk estimates of any fracture and hip fracture generated by each of the algorithms were compared. Setting The MS clinic at the Royal London Hospital. Participants 88 patients with a confirmed diagnosis of MS. Outcome measures Mean 10-year overall fracture risk and hip fracture risk were calculated using each of the three fracture risk calculators. The number of interventions that would be required as a result of using each of these tools was also compared. Results Mean 10-year fracture risk was 4.7%, 2.3% and 7.6% using FRAX, QFracture and the MS-specific calculator, respectively (p<0.0001 for difference). The agreement between risk scoring tools was poor at all levels of fracture risk. Conclusions The agreement between these three fracture risk scoring tools is poor in the MS population. Further work is required to develop and validate an accurate fracture risk scoring system for use in MS. Trial registration This service development study was approved by the Clinical Effectiveness Department at Barts Health NHS Trust (project registration number 156/12). PMID:23482989

  18. Quantitative analysis of polyethylene glycol (PEG) and PEGylated proteins in animal tissues by LC-MS/MS coupled with in-source CID.

    PubMed

    Gong, Jiachang; Gu, Xiaomei; Achanzar, William E; Chadwick, Kristina D; Gan, Jinping; Brock, Barry J; Kishnani, Narendra S; Humphreys, W Griff; Iyer, Ramaswamy A

    2014-08-05

    The covalent conjugation of polyethylene glycol (PEG, typical MW > 10k) to therapeutic peptides and proteins is a well-established approach to improve their pharmacokinetic properties and diminish the potential for immunogenicity. Even though PEG is generally considered biologically inert and safe in animals and humans, the slow clearance of large PEGs raises concerns about potential adverse effects resulting from PEG accumulation in tissues following chronic administration, particularly in the central nervous system. The key information relevant to the issue is the disposition and fate of the PEG moiety after repeated dosing with PEGylated proteins. Here, we report a novel quantitative method utilizing LC-MS/MS coupled with in-source CID that is highly selective and sensitive to PEG-related materials. Both (40K)PEG and a tool PEGylated protein (ATI-1072) underwent dissociation in the ionization source of mass spectrometer to generate a series of PEG-specific ions, which were subjected to further dissociation through conventional CID. To demonstrate the potential application of the method to assess PEG biodistribution following PEGylated protein administration, a single dose study of ATI-1072 was conducted in rats. Plasma and various tissues were collected, and the concentrations of both (40K)PEG and ATI-1072 were determined using the LC-MS/MS method. The presence of (40k)PEG in plasma and tissue homogenates suggests the degradation of PEGylated proteins after dose administration to rats, given that free PEG was absent in the dosing solution. The method enables further studies for a thorough characterization of disposition and fate of PEGylated proteins.

  19. Integrated metabolomic profiling of hepatocellular carcinoma in hepatitis C cirrhosis through GC/MS and UPLC/MS-MS.

    PubMed

    Fitian, Asem I; Nelson, David R; Liu, Chen; Xu, Yiling; Ararat, Miguel; Cabrera, Roniel

    2014-10-01

    The metabolic pathway disturbances associated with hepatocellular carcinoma (HCC) remain unsatisfactorily characterized. Determination of the metabolic alterations associated with the presence of HCC can improve our understanding of the pathophysiology of this cancer and may provide opportunities for improved disease monitoring of patients at risk for HCC development. To characterize the global metabolic alterations associated with HCC arising from hepatitis C (HCV)-associated cirrhosis using an integrated non-targeted metabolomics methodology employing both gas chromatography/mass spectrometry (GC/MS) and ultrahigh-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC/MS-MS). The global serum metabolomes of 30 HCC patients, 27 hepatitis C cirrhosis disease controls and 30 healthy volunteers were characterized using a metabolomics approach that combined two metabolomics platforms, GC/MS and UPLC/MS-MS. Random forest, multivariate statistics and receiver operator characteristic analysis were performed to identify the most significantly altered metabolites in HCC patients vs. HCV-cirrhosis controls and which therefore exhibited a close association with the presence of HCC. Elevated 12-hydroxyeicosatetraenoic acid (12-HETE), 15-HETE, sphingosine, γ-glutamyl oxidative stress-associated metabolites, xanthine, amino acids serine, glycine and aspartate, and acylcarnitines were strongly associated with the presence of HCC. Elevations in bile acids and dicarboxylic acids were highly correlated with cirrhosis. Integrated metabolomic profiling through GC/MS and UPLC/MS-MS identified global metabolic disturbances in HCC and HCV-cirrhosis. Aberrant amino acid biosynthesis, cell turnover regulation, reactive oxygen species neutralization and eicosanoid pathways may be hallmarks of HCC. Aberrant dicarboxylic acid metabolism, enhanced bile acid metabolism and elevations in fibrinogen cleavage peptides may be signatures of cirrhosis. © 2014 John

  20. Identification and Characterization of Reaction Products of 5-Hydroxytryptamine with Methylglyoxal and Glyoxal by LC/MS/MS.

    PubMed

    Sai Sachin, L; Nagarjuna Chary, R; Pavankumar, P; Prabhakar, S

    2018-06-06

    The methylglyoxal (MGO) and glyoxal (GO) are known to be at high levels in the diabetic humans. They react with amine containing proteins and amino acids to form advanced glycation end products, however, the reactivity with the other amine containing metabolites, such as neurotransmitters are not explored. In this study, we aimed at studying the reactivity of 5-hydroxytryptamine (5-HT) with MGO or GO, which may alter the metabolic function of 5-HT. The stock solutions of 5-HT, MGO and GO were made in PBS buffer at pH 7.4 and incubated 5-HT with MGO or GO at difference concentrations. The reactions were also performed at physiological concentrations. The reaction mixtures collected at different incubation times were analyzed by direct ESI-HRMS, LC/MS and LC/MS/MS conditions to detect/characterize the products. Agilent 6545 Q-TOF and Agilent 6420 triple quadrupole mass spectrometer were used for the study, and LC separations were performed on a C18 column. The direct ESI-HRMS data of the reaction mixtures showed formation of three and four reaction products when 5-HT reacted with MGO and GO, respectively. All the products showed dominant [M+H] + ions. The products were characterized by HRMS, LC/MS/MS and the literature reports on similar compounds. The products can easily be identified by LC/MS based on the accurate mass values together with retention time information. The MS/MS of the reaction products showed structure indicative fragment ions. 5-HT reacts with one or two MGO/GO to form a set of reaction products. The reaction between 5-HT and MGO or GO was faster at higher concentrations of MGO/GO (<10 min), and the same products were found even at physiological concentrations (<48 hrs). The LC-MS/MS (SRM) method can be used to screen the reaction products when present at low level. This article is protected by copyright. All rights reserved.

  1. Phylogenetic Analysis of the MS4A and TMEM176 Gene Families

    PubMed Central

    Zuccolo, Jonathan; Bau, Jeremy; Childs, Sarah J.; Goss, Greg G.; Sensen, Christoph W.; Deans, Julie P.

    2010-01-01

    Background The MS4A gene family in humans includes CD20 (MS4A1), FcRβ (MS4A2), Htm4 (MS4A3), and at least 13 other syntenic genes encoding membrane proteins, most having characteristic tetraspanning topology. Expression of MS4A genes is variable in tissues throughout the body; however, several are limited to cells in the hematopoietic system where they have known roles in immune cell functions. Genes in the small TMEM176 group share significant sequence similarity with MS4A genes and there is evidence of immune function of at least one of the encoded proteins. In this study, we examined the evolutionary history of the MS4A/TMEM176 families as well as tissue expression of the phylogenetically earliest members, in order to investigate their possible origins in immune cells. Principal Findings Orthologs of human MS4A genes were found only in mammals; however, MS4A gene homologs were found in most jawed vertebrates. TMEM176 genes were found only in mammals and bony fish. Several unusual MS4A genes having 2 or more tandem MS4A sequences were identified in the chicken (Gallus gallus) and early mammals (opossum, Monodelphis domestica and platypus, Ornithorhyncus anatinus). A large number of highly conserved MS4A and TMEM176 genes was found in zebrafish (Danio rerio). The most primitive organism identified to have MS4A genes was spiny dogfish (Squalus acanthus). Tissue expression of MS4A genes in S. acanthias and D. rerio showed no evidence of expression restricted to the hematopoietic system. Conclusions/Significance Our findings suggest that MS4A genes first appeared in cartilaginous fish with expression outside of the immune system, and have since diversified in many species into their modern forms with expression and function in both immune and nonimmune cells. PMID:20186339

  2. Software ion scan functions in analysis of glycomic and lipidomic MS/MS datasets.

    PubMed

    Haramija, Marko

    2018-03-01

    Hardware ion scan functions unique to tandem mass spectrometry (MS/MS) mode of data acquisition, such as precursor ion scan (PIS) and neutral loss scan (NLS), are important for selective extraction of key structural data from complex MS/MS spectra. However, their software counterparts, software ion scan (SIS) functions, are still not regularly available. Software ion scan functions can be easily coded for additional functionalities, such as software multiple precursor ion scan, software no ion scan, and software variable ion scan functions. These are often necessary, since they allow more efficient analysis of complex MS/MS datasets, often encountered in glycomics and lipidomics. Software ion scan functions can be easily coded by using modern script languages and can be independent of instrument manufacturer. Here we demonstrate the utility of SIS functions on a medium-size glycomic MS/MS dataset. Knowledge of sample properties, as well as of diagnostic and conditional diagnostic ions crucial for data analysis, was needed. Based on the tables constructed with the output data from the SIS functions performed, a detailed analysis of a complex MS/MS glycomic dataset could be carried out in a quick, accurate, and efficient manner. Glycomic research is progressing slowly, and with respect to the MS experiments, one of the key obstacles for moving forward is the lack of appropriate bioinformatic tools necessary for fast analysis of glycomic MS/MS datasets. Adding novel SIS functionalities to the glycomic MS/MS toolbox has a potential to significantly speed up the glycomic data analysis process. Similar tools are useful for analysis of lipidomic MS/MS datasets as well, as will be discussed briefly. Copyright © 2017 John Wiley & Sons, Ltd.

  3. A simple, fast and sensitive screening LC-ESI-MS/MS method for antibiotics in fish.

    PubMed

    Guidi, Letícia Rocha; Santos, Flávio Alves; Ribeiro, Ana Cláudia S R; Fernandes, Christian; Silva, Luiza H M; Gloria, Maria Beatriz A

    2017-01-15

    The objective of this study was to develop and validate a fast, sensitive and simple liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the screening of six classes of antibiotics (aminoglycosides, beta-lactams, macrolides, quinolones, sulfonamides and tetracyclines) in fish. Samples were extracted with trichloroacetic acid. LC separation was achieved on a Zorbax Eclipse XDB C18 column and gradient elution using 0.1% heptafluorobutyric acid in water and acetonitrile as mobile phase. Analysis was carried out in multiple reaction monitoring mode via electrospray interface operated in the positive ionization mode, with sulfaphenazole as internal standard. The method was suitable for routine screening purposes of 40 antibiotics, according to EC Guidelines for the Validation of Screening Methods for Residues of Veterinary Medicines, taking into consideration threshold value, cut-off factor, detection capability, limit of detection, sensitivity and specificity. Real fish samples (n=193) from aquaculture were analyzed and 15% were positive for enrofloxacin (quinolone), one of them at a higher concentration than the level of interest (50µgkg -1 ), suggesting possible contamination or illegal use of that antibiotic. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Determination of a steroid profile in heel prick blood using LC-MS/MS.

    PubMed

    Boelen, Anita; Ruiter, An F C; Claahsen-van der Grinten, Hedi L; Endert, Erik; Ackermans, Mariette T

    2016-01-01

    The aim of this study was to improve the sensitivity of the congenital adrenal hyperplasia (CAH) neonatal screening by including second-tier steroid profiling on a DBS using LC-MS. We developed a method to measure the steroid profile in DBS and established gestational age-specific reference ranges of cortisol, cortisone, 11-deoxycortisol, 21-deoxycortisol, 17-hydroxyprogesterone, testosterone, Δ4-androstenedione, corticosterone and 11-deoxycorticosterone using 450 heel prick samples of neonates, participating in the Dutch Screening Program. Analyzing 92 cards with a positive CAH screening showed that only 21-deoxycortisol was 100% specific for diagnosed CAH patients. Steroid precursors can be measured in DBS and we suggest to implement the method as a second tier testing for CAH in The Netherlands.

  5. Sedentary behaviour in people with multiple sclerosis: Is it time to stand up against MS?

    PubMed

    Veldhuijzen van Zanten, Jet Jcs; Pilutti, Lara A; Duda, Joan L; Motl, Robert W

    2016-09-01

    Historically, people with multiple sclerosis (MS) have been considered sedentary, although the actual scientific study of sedentary behaviour in MS did not originate until 2011. Sedentary behaviour, which is conceptually distinct from physical inactivity, is defined as any waking activity characterised by an energy expenditure ⩽ 1.5 metabolic equivalents and in a sitting or reclining posture. In the general population, the volume of sitting time is associated with increased risks of morbidity and mortality, independent of physical activity, and has been suggested to carry a greater risk of mortality than smoking behaviour. There are many symptoms of MS (e.g. mobility disability and fatigue) that could increase the prevalence of sedentary behaviour, and sedentary behaviour may have considerable implications for the development of comorbid conditions prevalent in MS. This review provides a summary of the rates, correlates, consequences and interventions attempting to reduce sedentary behaviour in MS. We provide a research agenda that guides future research on sedentary behaviour in MS. This paper provides a clarion call that it is time to 'stand up against MS'. © The Author(s), 2016.

  6. Multicenter Study Evaluating the Vitek MS System for Identification of Medically Important Yeasts

    PubMed Central

    Westblade, Lars F.; Jennemann, Rebecca; Branda, John A.; Bythrow, Maureen; Ferraro, Mary Jane; Garner, Omai B.; Ginocchio, Christine C.; Lewinski, Michael A.; Manji, Ryhana; Mochon, A. Brian; Procop, Gary W.; Richter, Sandra S.; Rychert, Jenna A.; Sercia, Linda

    2013-01-01

    The optimal management of fungal infections is correlated with timely organism identification. Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry (MS) is revolutionizing the identification of yeasts isolated from clinical specimens. We present a multicenter study assessing the performance of the Vitek MS system (bioMérieux) in identifying medically important yeasts. A collection of 852 isolates was tested, including 20 Candida species (626 isolates, including 58 C. albicans, 62 C. glabrata, and 53 C. krusei isolates), 35 Cryptococcus neoformans isolates, and 191 other clinically relevant yeast isolates; in total, 31 different species were evaluated. Isolates were directly applied to a target plate, followed by a formic acid overlay. Mass spectra were acquired using the Vitek MS system and were analyzed using the Vitek MS v2.0 database. The gold standard for identification was sequence analysis of the D2 region of the 26S rRNA gene. In total, 823 isolates (96.6%) were identified to the genus level and 819 isolates (96.1%) were identified to the species level. Twenty-four isolates (2.8%) were not identified, and five isolates (0.6%) were misidentified. Misidentified isolates included one isolate of C. albicans (n = 58) identified as Candida dubliniensis, one isolate of Candida parapsilosis (n = 73) identified as Candida pelliculosa, and three isolates of Geotrichum klebahnii (n = 6) identified as Geotrichum candidum. The identification of clinically relevant yeasts using MS is superior to the phenotypic identification systems currently employed in clinical microbiology laboratories. PMID:23658267

  7. Multicenter study evaluating the Vitek MS system for identification of medically important yeasts.

    PubMed

    Westblade, Lars F; Jennemann, Rebecca; Branda, John A; Bythrow, Maureen; Ferraro, Mary Jane; Garner, Omai B; Ginocchio, Christine C; Lewinski, Michael A; Manji, Ryhana; Mochon, A Brian; Procop, Gary W; Richter, Sandra S; Rychert, Jenna A; Sercia, Linda; Burnham, Carey-Ann D

    2013-07-01

    The optimal management of fungal infections is correlated with timely organism identification. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is revolutionizing the identification of yeasts isolated from clinical specimens. We present a multicenter study assessing the performance of the Vitek MS system (bioMérieux) in identifying medically important yeasts. A collection of 852 isolates was tested, including 20 Candida species (626 isolates, including 58 C. albicans, 62 C. glabrata, and 53 C. krusei isolates), 35 Cryptococcus neoformans isolates, and 191 other clinically relevant yeast isolates; in total, 31 different species were evaluated. Isolates were directly applied to a target plate, followed by a formic acid overlay. Mass spectra were acquired using the Vitek MS system and were analyzed using the Vitek MS v2.0 database. The gold standard for identification was sequence analysis of the D2 region of the 26S rRNA gene. In total, 823 isolates (96.6%) were identified to the genus level and 819 isolates (96.1%) were identified to the species level. Twenty-four isolates (2.8%) were not identified, and five isolates (0.6%) were misidentified. Misidentified isolates included one isolate of C. albicans (n = 58) identified as Candida dubliniensis, one isolate of Candida parapsilosis (n = 73) identified as Candida pelliculosa, and three isolates of Geotrichum klebahnii (n = 6) identified as Geotrichum candidum. The identification of clinically relevant yeasts using MS is superior to the phenotypic identification systems currently employed in clinical microbiology laboratories.

  8. Algorithms for database-dependent search of MS/MS data.

    PubMed

    Matthiesen, Rune

    2013-01-01

    The frequent used bottom-up strategy for identification of proteins and their associated modifications generate nowadays typically thousands of MS/MS spectra that normally are matched automatically against a protein sequence database. Search engines that take as input MS/MS spectra and a protein sequence database are referred as database-dependent search engines. Many programs both commercial and freely available exist for database-dependent search of MS/MS spectra and most of the programs have excellent user documentation. The aim here is therefore to outline the algorithm strategy behind different search engines rather than providing software user manuals. The process of database-dependent search can be divided into search strategy, peptide scoring, protein scoring, and finally protein inference. Most efforts in the literature have been put in to comparing results from different software rather than discussing the underlining algorithms. Such practical comparisons can be cluttered by suboptimal implementation and the observed differences are frequently caused by software parameters settings which have not been set proper to allow even comparison. In other words an algorithmic idea can still be worth considering even if the software implementation has been demonstrated to be suboptimal. The aim in this chapter is therefore to split the algorithms for database-dependent searching of MS/MS data into the above steps so that the different algorithmic ideas become more transparent and comparable. Most search engines provide good implementations of the first three data analysis steps mentioned above, whereas the final step of protein inference are much less developed for most search engines and is in many cases performed by an external software. The final part of this chapter illustrates how protein inference is built into the VEMS search engine and discusses a stand-alone program SIR for protein inference that can import a Mascot search result.

  9. Distribution of toxic alkaloids in tissues from three herbal medicine Aconitum species using laser micro-dissection, UHPLC-QTOF MS and LC-MS/MS techniques.

    PubMed

    Jaiswal, Yogini; Liang, Zhitao; Ho, Alan; Wong, LaiLai; Yong, Peng; Chen, Hubiao; Zhao, Zhongzhen

    2014-11-01

    Aconite poisoning continues to be a major type of poisoning caused by herbal drugs in many countries. Nevertheless, despite its toxic characteristics, aconite is used because of its valuable therapeutic benefits. The aim of the present study was to determine the distribution of toxic alkaloids in tissues of aconite roots through chemical profiling. Three species were studied, all being used in traditional Chinese Medicine (TCM) and traditional Indian medicine (Ayurveda), namely: Aconitum carmichaelii, Aconitum kusnezoffii and Aconitum heterophyllum. Laser micro-dissection was used for isolation of target microscopic tissues, such as the metaderm, cortex, xylem, pith, and phloem, with ultra-high performance liquid chromatography equipped with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS) employed for detection of metabolites. Using a multi-targeted approach through auto and targeted LC-MS/MS, 48 known compounds were identified and the presence of aconitine, mesaconitine and hypaconitine that are the biomarkers of this plant was confirmed in the tissues. These results suggest that the three selected toxic alkaloids were exclusively found in A. carmichaelii and A. kusnezoffii. The most toxic components were found in large A. carmichaelii roots with more lateral root projections, and specifically in the metaderm, cork and vascular bundle tissues. The results from metabolite profiling were correlated with morphological features to predict the tissue specific distribution of toxic components and toxicity differences among the selected species. By careful exclusion of tissues having toxic diester diterpenoid alkaloids, the beneficial effects of aconite can still be retained and the frequency of toxicity occurrences can be greatly reduced. Knowledge of tissue-specific metabolite distribution can guide users and herbal drug manufacturers in prudent selection of relatively safer and therapeutically more effective parts of the root. The information provided from

  10. Analysis of Phosphonic Acids: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS999

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Owens, J; Vu, A; Koester, C

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled Analysis of Diisopropyl Methylphosphonate, Ethyl Hydrogen Dimethylamidophosphate, Isopropyl Methylphosphonic Acid, Methylphosphonic Acid, and Pinacolyl Methylphosphonic Acid in Water by Multiple Reaction Monitoring Liquid Chromatography/Tandem Mass Spectrometry: EPA Version MS999. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures describedmore » in EPA Method MS999 for analysis of the listed phosphonic acids and surrogates in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of EPA Method MS999 can be determined.« less

  11. UPLC-MS/MS determination and gender-related pharmacokinetic study of five active ingredients in rat plasma after oral administration of Eucommia cortex extract.

    PubMed

    Hu, Fangdi; An, Jing; Li, Wen; Zhang, Zijia; Chen, Wenxia; Wang, Changhong; Wang, Zhengtao

    2015-07-01

    linearity over a wide concentration range, the lower limits of quantification and higher accuracy and precision for determination of the 5 analytes. Then the method was applied to study the pharmacokinetics in rats, and the results indicated that there were significant differences in pharmacokinetic parameters of the analytes between the male and female rats, and absorptions of these analytes in male group were all significantly higher than those in female group. This study established an efficient, sensitive and selective UPLC-MS/MS method for simultaneous determination of the five ingredients in rat plasma, and it could be successfully applied to the comparative pharmacokinetic studies in male and female rats after oral administration with EC extract. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Suggested Format for Acute Toxicity Studies

    EPA Pesticide Factsheets

    This document suggests the format for final reports on pesticide studies (right column of the tables in the document) and provides instructions for the creation of PDF Version 1.3 electronic submission documents (left column of the tables).

  13. Screening for the risk of job loss in multiple sclerosis (MS): development of an MS-specific Work Instability Scale (MS-WIS).

    PubMed

    McFadden, Estelle; Horton, Mike C; Ford, Helen L; Gilworth, Gill; McFadden, Majella; Tennant, Alan

    2012-06-01

    Multiple sclerosis (MS) mainly presents amongst those of working age. Depending upon the type of MS, many people embark upon a long period of managing their day-to-day work-related needs in the face of intermittent and sometimes persistent disabling symptoms. The objective of this study was to explore the concept of work instability (WI) following the onset of MS and develop a Work Instability Scale (WIS) specific to this population. WI amongst those with MS in work was explored through qualitative interviews which were then used to generate items for a WIS. Rasch analysis was used to refine the scaling properties of the MS-WIS, which was then validated against expert vocational assessment by occupational health physiotherapists and ergonomists. The resulting measure is a 22-item, self-administered scale which can be scored in three bands indicating low, medium and high risk of WI (job retention) problems. The scale meets modern psychometric requirements for measurement, indicated by adequate fit to the Rasch model with absence of local dependency and differential item functioning (DIF) by age, gender and hours worked. The scale presents an opportunity in routine clinical practice to take positive action to reduce sickness absence and prevent job loss.

  14. Preliminary study of urine metabolism in type two diabetic patients based on GC-MS

    PubMed Central

    Zhang, Ning; Geng, Fang; Hu, Zhong-Hua; Liu, Bin; Wang, Ye-Qiu; Liu, Jun-Cen; Qi, Yong-Hua; Li, Li-Jing

    2016-01-01

    Objective: Comparative study of type 2 diabetes and healthy controls by metabolomics methods to explore the pathogenesis of Type II diabetes. Methods: Gas chromatography - mass spectrometry (GC-MS) with a variety of multivariate statistical analysis methods to the healthy control group 58 cases, 68 cases of Type II diabetes group were analyzed. Chromatographic conditions: DB-5MS column; the carrier gas He; flow rate of 1 mL·min-1, the injection volume 1 uL; split ratio is 100: 1. MS conditions: electron impact (EI) ion source, an auxiliary temperature of 280°C, the ion source 230°C, quadrupole 150°C; mass scan range 30~600 mAu. Results: Established analytical method based on urine metabolomics GC-MS of Type II diabetes, determine the urine succinic acid, L-leucine, L-isoleucine, tyrosine, slanine, acetoace acid, mannose, L-isoleucine, L-threonine, Phenylalanine, fructose, D-glucose, palmi acid, oleic acid and arachidonic acid were significantly were significantly changed. Conclusion: Based on metabolomics of GC-MS detection and analysis metabolites can be found differences between type 2 diabetes and healthy control group, PCA diagram can effectively distinguish Type II diabetes and healthy control group, with load diagrams and PLS-DA VIP value metabolite screening, the resulting differences in metabolic pathways involved metabolites, including amino acid metabolism, lipid metabolism, glucose metabolism and energy metabolism. PMID:27508010

  15. Chiral analyses of dextromethorphan/levomethorphan and their metabolites in rat and human samples using LC-MS/MS.

    PubMed

    Kikura-Hanajiri, Ruri; Kawamura, Maiko; Miyajima, Atsuko; Sunouchi, Momoko; Goda, Yukihiro

    2011-04-01

    In order to develop an analytical method for the discrimination of dextromethorphan (an antitussive medicine) from its enantiomer, levomethorphan (a narcotic) in biological samples, chiral analyses of these drugs and their O-demethyl and/or N-demethyl metabolites in rat plasma, urine, and hair were carried out using LC-MS/MS. After the i.p. administration of dextromethorphan or levomethorphan to pigmented hairy male DA rats (5 mg/kg/day, 10 days), the parent compounds and their three metabolites in plasma, urine and hair were determined using LC-MS/MS. Complete chiral separation was achieved in 12 min on a Chiral CD-Ph column in 0.1% formic acid-acetonitrile by a linear gradient program. Most of the metabolites were detected as being the corresponding O-demethyl and N, O-didemethyl metabolites in the rat plasma and urine after the hydrolysis of O-glucuronides, although obvious differences in the amounts of these metabolites were found between the dextro and levo forms. No racemation was observed through O- and/or N-demethylation. In the rat hair samples collected 4 weeks after the first administration, those differences were more clearly detected and the concentrations of the parent compounds, their O-demethyl, N-demethyl, and N, O-didemethyl metabolites were 63.4, 2.7, 25.1, and 0.7 ng/mg for the dextro forms and 24.5, 24.6, 2.6, and 0.5 ng/mg for the levo forms, respectively. In order to fully investigate the differences of their metabolic properties between dextromethorphan and levomethorphan, DA rat and human liver microsomes were studied. The results suggested that there might be an enantioselective metabolism of levomethorphan, especially with regard to the O-demethylation, not only in DA rat but human liver microsomes as well. The proposed chiral analyses might be applied to human samples and could be useful for discriminating dextromethorphan use from levomethorphan use in the field of forensic toxicology, although further studies should be carried out

  16. Automated protein identification by the combination of MALDI MS and MS/MS spectra from different instruments.

    PubMed

    Levander, Fredrik; James, Peter

    2005-01-01

    The identification of proteins separated on two-dimensional gels is most commonly performed by trypsin digestion and subsequent matrix-assisted laser desorption ionization (MALDI) with time-of-flight (TOF). Recently, atmospheric pressure (AP) MALDI coupled to an ion trap (IT) has emerged as a convenient method to obtain tandem mass spectra (MS/MS) from samples on MALDI target plates. In the present work, we investigated the feasibility of using the two methodologies in line as a standard method for protein identification. In this setup, the high mass accuracy MALDI-TOF spectra are used to calibrate the peptide precursor masses in the lower mass accuracy AP-MALDI-IT MS/MS spectra. Several software tools were developed to automate the analysis process. Two sets of MALDI samples, consisting of 142 and 421 gel spots, respectively, were analyzed in a highly automated manner. In the first set, the protein identification rate increased from 61% for MALDI-TOF only to 85% for MALDI-TOF combined with AP-MALDI-IT. In the second data set the increase in protein identification rate was from 44% to 58%. AP-MALDI-IT MS/MS spectra were in general less effective than the MALDI-TOF spectra for protein identification, but the combination of the two methods clearly enhanced the confidence in protein identification.

  17. SIFT-MS and FA-MS methods for ambient gas phase analysis: developments and applications in the UK.

    PubMed

    Smith, David; Španěl, Patrik

    2015-04-21

    Selected ion flow tube mass spectrometry, SIFT-MS, a relatively new gas/vapour phase analytical method, is derived from the much earlier selected ion flow tube, SIFT, used for the study of gas phase ion-molecule reactions. Both the SIFT and SIFT-MS techniques were conceived and developed in the UK, the former at Birmingham University, the latter at Keele University along with the complementary flowing afterglow mass spectrometry, FA-MS, technique. The focus of this short review is largely to describe the origins, developments and, most importantly, the unique features of SIFT-MS as an analytical tool for ambient analysis and to indicate its growing use to analyse humid air, especially exhaled breath, its unique place as a on-line, real time analytical method and its growing use and applications as a non-invasive diagnostic in clinical diagnosis and therapeutic monitoring, principally within several UK universities and hospitals, and briefly in the wider world. A few case studies are outlined that show the potential of SIFT-MS and FA-MS in the detection and quantification of metabolites in exhaled breath as a step towards recognising pathophysiology indicative of disease and the presence of bacterial and fungal infection of the airways and lungs. Particular cases include the detection of Pseudomonas aeruginosa infection of the airways of patients with cystic fibrosis (SIFT-MS) and the measurement of total body water in patients with chronic kidney disease (FA-MS). The growing exploitation of SIFT-MS in other areas of research and commerce are briefly listed to show the wide utility of this unique UK-developed analytical method, and future prospects and developments are alluded to.

  18. Pharmacokinetic based study on "lagged stimulation" of Curcumae Longae Rhizoma - Piper nigrum couplet in their main active components' metabolism using UPLC-MS-MS.

    PubMed

    Chen, Zhao; Sun, Dongmei; Bi, Xiaoli; Zeng, Xiaohui; Luo, Wenhui; Cai, Dake; Zeng, Qiaohuang; Xu, Aili

    2017-04-15

    TCM formula especially the couplets, as well as a fast, selective and sensitive UPLC-MS-MS method determining active components in-vivo. Furthermore, the finding of "lagged stimulation" suggested that the use of complex formula should take pharmacokinetics into much more careful consideration. Copyright © 2017 Elsevier GmbH. All rights reserved.

  19. Metabolism of the tryptamine-derived new psychoactive substances 5-MeO-2-Me-DALT, 5-MeO-2-Me-ALCHT, and 5-MeO-2-Me-DIPT and their detectability in urine studied by GC-MS, LC-MSn , and LC-HR-MS/MS.

    PubMed

    Caspar, Achim T; Gaab, Jonas B; Michely, Julian A; Brandt, Simon D; Meyer, Markus R; Maurer, Hans H

    2018-01-01

    Many N,N-dialkylated tryptamines show psychoactive properties and were encountered as new psychoactive substances. The aims of the presented work were to study the phase I and II metabolism and the detectability in standard urine screening approaches (SUSA) of 5-methoxy-2-methyl-N,N-diallyltryptamine (5-MeO-2-Me-DALT), 5-methoxy-2-methyl-N-allyl-N-cyclohexyltryptamine (5-MeO-2-Me-ALCHT), and 5-methoxy-2-methyl-N,N-diisopropyltryptamine (5-MeO-2-Me-DIPT) using gas chromatography-mass spectrometry (GC-MS), liquid chromatography coupled with multistage accurate mass spectrometry (LC-MS n ), and liquid chromatography-high-resolution tandem mass spectrometry (LC-HR-MS/MS). For metabolism studies, urine was collected over a 24 h period after administration of the compounds to male Wistar rats at 20 mg/kg body weight (BW). Phase I and II metabolites were identified after urine precipitation with acetonitrile by LC-HR-MS/MS. 5-MeO-2-Me-DALT (24 phase I and 12 phase II metabolites), 5-MeO-2-Me-ALCHT (24 phase I and 14 phase II metabolites), and 5-MeO-2-Me-DIPT (20 phase I and 11 phase II metabolites) were mainly metabolized by O-demethylation, hydroxylation, N-dealkylation, and combinations of them as well as by glucuronidation and sulfation of phase I metabolites. Incubations with mixtures of pooled human liver microsomes and cytosols (pHLM and pHLC) confirmed that the main metabolic reactions in humans and rats might be identical. Furthermore, initial CYP activity screenings revealed that CYP1A2, CYP2C19, CYP2D6, and CYP3A4 were involved in hydroxylation, CYP2C19 and CYP2D6 in O-demethylation, and CYP2C19, CYP2D6, and CYP3A4 in N-dealkylation. For SUSAs, GC-MS, LC-MS n , and LC-HR-MS/MS were applied to rat urine samples after 1 or 0.1 mg/kg BW doses, respectively. In contrast to the GC-MS SUSA, both LC-MS SUSAs were able to detect an intake of 5-MeO-2-Me-ALCHT and 5-MeO-2-Me-DIPT via their metabolites following 1 mg/kg BW administrations and 5-MeO-2-Me-DALT following

  20. Single hair analysis of small molecules using MALDI-triple quadrupole MS imaging and LC-MS/MS: investigations on opportunities and pitfalls.

    PubMed

    Poetzsch, Michael; Steuer, Andrea E; Roemmelt, Andreas T; Baumgartner, Markus R; Kraemer, Thomas

    2014-12-02

    Single hair analysis normally requires extensive sample preparation microscale protocols including time-consuming steps like segmentation and extraction. Matrix assisted laser desorption and ionization mass spectrometric imaging (MALDI-MSI) was shown to be an alternative tool in single hair analysis, but still, questions remain. Therefore, an investigation of MALDI-MSI in single hair analysis concerning the extraction process, usage of internal standard (IS), and influences on the ionization processes were systematically investigated to enable the reliable application to hair analysis. Furthermore, single dose detection, quantitative correlation to a single hair, and hair strand LC-MS/MS results were performed, and the performance was compared to LC-MS/MS single hair monitoring. The MALDI process was shown to be independent from natural hair color and not influenced by the presence of melanin. Ionization was shown to be reproducible along and in between different hair samples. MALDI image intensities in single hair and hair snippets showed good semiquantitative correlation to zolpidem hair concentrations obtained from validated routine LC-MS/MS methods. MALDI-MSI is superior to LC-MS/MS analysis when a fast, easy, and cheap sample preparation is necessary, whereas LC-MS/MS showed higher sensitivity with the ability of single dose detection for zolpidem. MALDI-MSI and LC-MS/MS segmental single hair analysis showed good correlation, and both are suitable for consumption monitoring of drugs of abuse with a high time resolution.

  1. Selective and comprehensive analysis of organohalogen compounds by GC × GC-HRTofMS and MS/MS.

    PubMed

    Hashimoto, Shunji; Zushi, Yasuyuki; Takazawa, Yoshikatsu; Ieda, Teruyo; Fushimi, Akihiro; Tanabe, Kiyoshi; Shibata, Yasuyuki

    2018-03-01

    Thousands of organohalogen compounds, including hazardous chemicals such as polychlorinated biphenyls (PCBs) and other persistent organic pollutants (POPs), were selectively and simultaneously detected and identified with simple, or no, purification from environmental sample extracts by using several advanced methods. The methods used were software extraction from two-dimensional gas chromatography-high-resolution time-of-flight mass spectrometry (GC × GC-HRTofMS) data, measurement by negative chemical ionization with HRTofMS, and neutral loss scanning (NLS) with GC × GC-MS/MS. Global and selective detection of organochlorines and bromines in environmental samples such as sediments and fly ash was achieved by NLS using GC × GC-MS/MS (QQQ), with the expected losses of 35 Cl and 79 Br. We confirmed that negative chemical ionization was effective for sensitive and selective ionization of organohalogens, even using GC × GC-HRTofMS. The 2D total ion chromatograms obtained by using negative chemical ionization and selective extraction of organohalogens using original software from data measured by electron impact ionization were very similar; the software thus functioned well to extract organohalogens. Combining measurements made by using these different methods will help to detect organohalogens selectively and globally. However, to compare the data obtained by individual measurements, the retention times of the peaks on the 2D chromatograms need to match.

  2. The EIPeptiDi tool: enhancing peptide discovery in ICAT-based LC MS/MS experiments.

    PubMed

    Cannataro, Mario; Cuda, Giovanni; Gaspari, Marco; Greco, Sergio; Tradigo, Giuseppe; Veltri, Pierangelo

    2007-07-15

    Isotope-coded affinity tags (ICAT) is a method for quantitative proteomics based on differential isotopic labeling, sample digestion and mass spectrometry (MS). The method allows the identification and relative quantification of proteins present in two samples and consists of the following phases. First, cysteine residues are either labeled using the ICAT Light or ICAT Heavy reagent (having identical chemical properties but different masses). Then, after whole sample digestion, the labeled peptides are captured selectively using the biotin tag contained in both ICAT reagents. Finally, the simplified peptide mixture is analyzed by nanoscale liquid chromatography-tandem mass spectrometry (LC-MS/MS). Nevertheless, the ICAT LC-MS/MS method still suffers from insufficient sample-to-sample reproducibility on peptide identification. In particular, the number and the type of peptides identified in different experiments can vary considerably and, thus, the statistical (comparative) analysis of sample sets is very challenging. Low information overlap at the peptide and, consequently, at the protein level, is very detrimental in situations where the number of samples to be analyzed is high. We designed a method for improving the data processing and peptide identification in sample sets subjected to ICAT labeling and LC-MS/MS analysis, based on cross validating MS/MS results. Such a method has been implemented in a tool, called EIPeptiDi, which boosts the ICAT data analysis software improving peptide identification throughout the input data set. Heavy/Light (H/L) pairs quantified but not identified by the MS/MS routine, are assigned to peptide sequences identified in other samples, by using similarity criteria based on chromatographic retention time and Heavy/Light mass attributes. EIPeptiDi significantly improves the number of identified peptides per sample, proving that the proposed method has a considerable impact on the protein identification process and, consequently, on

  3. High-throughput and rapid quantification of lipids by nanoflow UPLC-ESI-MS/MS: application to the hepatic lipids of rabbits with nonalcoholic fatty liver disease.

    PubMed

    Byeon, Seul Kee; Lee, Jong Cheol; Chung, Bong Chul; Seo, Hong Seog; Moon, Myeong Hee

    2016-07-01

    A rapid and high-throughput quantification method (approximately 300 lipids within 20 min) was established using nanoflow ultrahigh-pressure liquid chromatography-tandem mass spectrometry (nUPLC-ESI-MS/MS) with selective reaction monitoring (SRM) and applied to the quantitative profiling of the hepatic lipids of rabbits with different metabolic conditions that stimulate the development of nonalcoholic fatty liver disease (NAFLD). Among the metabolic conditions of rabbits in this study [inflammation (I), high-cholesterol diet (HC), and high-cholesterol diet combined with inflammation (HCI)], significant perturbation in hepatic lipidome (>3-fold and p < 0.01) was observed in the HC and HCI groups, while no single lipid showed a significant change in group I. In addition, this study revealed a dramatic increase (>2-fold) in relatively high-abundant monohexosylceramides (MHCs), sphingomyelins (SMs), and triacylglycerols (TGs) in both the HC and HCI groups, especially in MHCs as all 11 MHCs increased by larger than 3- to 12-fold. As the levels of the relatively high-abundant lipids in the above classes increased, the total lipidome level of each class increased significantly by approximately 2-fold to 5-fold. Other classes of lipids also generally increased, which was likely induced by the increase in mitogenic and nonapoptotic MHCs and SMs, as they promote cell proliferation. On the other hand, a slight decrease in the level of apoptotic ceramides (Cers) was observed, which agreed with the general increase in total lipid level. As distinct changes in hepatic lipidome were observed from HC groups, this suggests that HC or HCI is highly associated with NAFLD but not inflammation alone itself. Graphical Abstract Schematic of lipidomic analysis from hepatic tissue using nanoflow LC-ESI-MS/MS and nUPLC-ESI-MS/MS.

  4. [Construction, expression and immunogenicity study of a chimeric MS/hIL-12 eukaryotic expression plasmid].

    PubMed

    Li, Hui; Li, Rong; Zhong, Sen; Ren, Hong; Deng, Cun-liang; Shi, Xiao-ling; Wang, Ming-yong

    2006-04-01

    To construct and express a chimeric Mtb8.4 with signal peptide (MS)/hIL12 eukaryotic expression plasmid, and to study the immunogenicity of the MS/hIL-12 chimeric genetic vaccines. The MS/hIL-12 chimeric gene was amplified by polymerase chain reaction (PCR) and cloned into the eukaryotic expression vector pCI-neo. The correct pCI-neo-MS/hIL12 (pMSI) recombinant plasmid was identified by PCR, restricted enzyme digestion and DNA sequencing. COS-7 cells were transfected with pMSI constructs by cationic liposome. After 48 hours, mRNA of the target gene was detected by RT-PCR, and hIL-12 protein in culture supernatant and cell lysates was detected by Western blot. C57BL/6N mice were vaccinated with MS/hIL-12 chimeric gene vaccine for three times at 3 week intervals. Four weeks after the final inoculation, three mice were sacrificed for measurement of the cytokine response and cytotoxic T lymphocyte (CTL) induction. The accuracy of plasmid construction was confirmed by a number of molecular biological techniques. Transfection of COS-7 cells with plasmids pMSI lead to transient expression of fusion proteins. The IFN-gamma and IL-2 titers were (1,521 +/- 48) ng/L and (755 +/- 41) ng/L in MS/hIL-12 chimeric gene vaccine group, (820 +/- 50) ng/L and (297 +/- 31) ng/L in MS gene vaccine group, (1,487 +/- 40) ng/L and (767 +/- 50) ng/L in BCG group, (121 +/- 16) ng/L and (62 +/- 10) ng/L in vacant vector group, and (48 +/- 16) ng/L and (32 +/- 17) ng/L in PBS group respectively. The levels of IFN-gamma and IL-2 in MS/hIL-12 chimeric gene vaccine group were higher than those of MS gene vaccine group, vacant vector group and PBS group (P < 0.01) and was similar to the BCG group (P > 0.05). The level of IL-4 in BCG group [(91 +/- 11) ng/L] increased significantly as compared to other groups (P < 0.01). When effector-cell-to-target-cell ratio (E:T ratio) were 100:1, 50:1, and 10:1 respectively, the CTL activity was 77.5%, 51.2%, 30.3% in MS/hIL-12 chimeric gene vaccine group, 56

  5. BMI levels with MS Bone mineral density levels in adults with multiple sclerosis: a meta-analysis.

    PubMed

    Huang, Zhongming; Qi, Yiying; Du, Shaohua; Chen, Guangnan; Yan, Weiqi

    2015-01-01

    Multiple sclerosis (MS) and osteoporosis (OP) affect a substantial proportion of the population. Accumulating evidence suggests that MS patients are at high risk for OP. We performed a meta-analysis to identify risk factors for lowered bone mineral density (BMD) in MS patients. We searched for articles within the Medline, Embase and Cochrane Library databases, published up to March 2014, pertaining to associations between MS and BMD. A total of 11 studies was included in the meta-analysis. The analysis indicated that MS patients have reduced lumbar spine, femur neck, and hip BMD compared with healthy controls (lumbar spine, standardized mean difference (SMD) = -0.76, 95% CI: -1.07, -0.45; femur neck, SMD = -0.56, 95% CI: -0.84, -0.29; and hip, SMD = -0.62, 95% CI: -0.96, -0.29). Further subgroup analysis revealed that a disease duration of >7 years, total steroid dose during the disease of >15 g, and an Expanded Disability Status Scale (EDSS) score of > 3, increased the risk of reduced BMD in the lumbar spine and femoral neck, but not in the hip. Meta-regression analysis did not explain the heterogeneity in the clinical characteristics or outcome definitions. Our meta-analysis suggests that MS patients have reduced overall BMD compared with healthy controls. Furthermore, disease duration (>7 years), total steroid dose (>15 g), and EDSS score (>3) are risk factors for reduced BMD in MS patients.

  6. Determination of carbohydrates in medicinal plants--comparison between TLC, mf-MELDI-MS and GC-MS.

    PubMed

    Qureshi, Muhammad Nasimullah; Stecher, Guenther; Sultana, Tahira; Abel, Gudrun; Popp, Michael; Bonn, Guenther K

    2011-01-01

    Quality control in the pharmaceutical and phytopharmaceutical industries requires fast and reliable methods for the analysis of raw materials and final products. This study evaluates different analytical approaches in order to recognise the most suitable technique for the analysis of carbohydrates in herbal drug preparations. The specific focus of the study is on thin-layer chromatography (TLC), gas chromatography (GC), and a newly developed mass spectrometric method, i.e. matrix free material enhanced laser desorption/ionisation time of flight mass spectrometry (mf-MELDI-MS). Samples employed in the study were standards and microwave-assisted water extracts from Quercus. TLC analysis proved the presence of mono-, di- and trisaccharides within the biological sample and hinted at the existence of an unknown carbohydrate of higher oligomerisation degree. After evaluation of different derivatisation techniques, GC-MS confirmed data obtained via TLC for mono- to trisaccharides, delivering additionally quantified values under a considerable amount of time. A carbohydrate of higher oligomerisation degree could not be found. The application of mf-MELDI-MS further confirmed the presence of carbohydrates up to trisaccharides, also hinting at the presence of a form of tetrasaccharide. Besides this information, mf-MELDI-MS delivered further data about other substances present in the extract. Quantitative determination resulted in 1.750, 1.736 and 0.336 mg/mL for glucose, sucrose and raffinose respectively. Evaluation of all three techniques employed, clearly proved the heightened performance of mf-MELDI-MS for the qualitative analysis of complex mixtures, as targets do not need modification and analysis requires only a few minutes. In addition, GC-MS is suitable for quantitative analysis. Copyright © 2011 John Wiley & Sons, Ltd.

  7. Validation Study on a Rapid Method for Simultaneous Determination of Pesticide Residues in Vegetables and Fruits by LC-MS/MS.

    PubMed

    Sato, Tamaki; Miyamoto, Iori; Uemura, Masako; Nakatani, Tadashi; Kakutani, Naoya; Yamano, Tetsuo

    2016-01-01

    A validation study was carried out on a rapid method for the simultaneous determination of pesticide residues in vegetables and fruits by LC-MS/MS. Preparation of the test solution was performed by a solid-phase extraction technique with QuEChERS (STQ method). Pesticide residues were extracted with acetonitrile using a homogenizer, followed by salting-out and dehydration at the same time. The acetonitrile layer was purified with C18 and PSA mini-columns. The method was assessed for 130 pesticide residues in 14 kinds of vegetables and fruits at the concentration level of 0.01 μg/g according to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan. As a result 75 to 120 pesticide residues were determined satisfactorily in the tested samples. Thus, this method could be useful for a rapid and simultaneous determination of multi-class pesticide residues in various vegetables and fruits.

  8. MS2 inactivation by TiO2 nanoparticles in the presence of quartz sand

    NASA Astrophysics Data System (ADS)

    Syngouna, Vasiliki I.; Chrysikopoulos, Constantinos V.

    2017-04-01

    Virus inactivation by nanoparticles (NPs) is hypothesized to affect virus fate and transport in the subsurface. This study examines the interactions of viruses with titanium dioxide (TiO2) anatase NPs, which is a good disinfectant with unique physiochemical properties, using three different virus concentrations. The bacteriophage MS2 was used as a model virus. A series of batch experiments of MS2 inactivation by TiO2 NPs were conducted at room temperature (25 °C), in the presence of quartz sand, with and without ambient light. The virus inactivation experimental data were satisfactorily fitted with a pseudo-first order expression with a time dependent rate coefficient. Quartz sand was shown to affect MS2 inactivation by TiO2 NPs both in the presence and absence of ambient light, because, under the experimental conditions of this study, the quartz sand offers a protection to the attached MS2 against inactivation. Moreover, in most cases similar inactivation rates were observed in reactor and control tubes (absence of TiO2 NPs) suggesting that low TiO2 concentration (10 mg/L) affects only slightly MS2 inactivation with and without ambient light.

  9. Multisteroid LC–MS/MS assay for glucocorticoids and androgens and its application in Addison's disease

    PubMed Central

    Methlie, Paal; Hustad, Steinar; Kellman, Ralf; Almås, Bjørg; Erichsen, Martina M; Husebye, Eystein S; Løvås, Kristian

    2013-01-01

    Objective Liquid chromatography–tandem mass spectrometry (LC–MS/MS) offers superior analytical specificity compared with immunoassays, but it is not available in many regions and hospitals due to expensive instrumentation and tedious sample preparation. Thus, we developed an automated, high-throughput LC–MS/MS assay for simultaneous quantification of ten endogenous and synthetic steroids targeting diseases of the hypothalamic–pituitary–adrenal axis and gonads. Methods Deuterated internal standards were added to 85 μl serum and processed by liquid–liquid extraction. Cortisol, cortisone, prednisolone, prednisone, 11-deoxycortisol, dexamethasone, testosterone, androstenedione and progesterone were resolved by ultra-high-pressure chromatography on a reversed-phase column in 6.1 min and detected by triple-quadrupole mass spectrometry. The method was used to assess steroid profiles in women with Addison's disease (AD, n=156) and blood donors (BDs, n=102). Results Precisions ranged from 4.5 to 10.1% relative standard deviations (RSD), accuracies from 95 to 108% and extraction recoveries from 60 to 84%. The method was practically free of matrix effects and robust to individual differences in serum composition. Most postmenopausal AD women had extremely low androstenedione concentrations, below 0.14 nmol/l, and median testosterone concentrations of 0.15 nmol/l (interquartile range 0.00–0.41), considerably lower than those of postmenopausal BDs (1.28 nmol/l (0.96–1.64) and 0.65 nmol/l (0.56–1.10) respectively). AD women in fertile years had androstenedione concentrations of 1.18 nmol/l (0.71–1.76) and testosterone concentrations of 0.44 nmol/l (0.22–0.63), approximately half of those found in BDs of corresponding age. Conclusion This LC–MS/MS assay provides highly sensitive and specific assessments of glucocorticoids and androgens with low sample volumes and is suitable for endocrine laboratories and research. Its utility has been

  10. Desirability and expectations of the UK MS Register: views of people with MS.

    PubMed

    Osborne, Lisa A; Middleton, Rodden M; Jones, Kerina H; Ford, David V; Noble, J Gareth

    2013-11-01

    Internet-based health registers are increasingly commonly used for health promotion and medical research, yet little is known about what the patient groups who help form the basis of such registers expect from these tools. Mismatches between patient expectations and the register design may limit the long-term utility of such registers. This study elicited the views of people with Multiple Sclerosis (PwMS) on the desirability and expectations regarding a UK Register for MS. Participants were recruited through a range of traditional means (newsletters, adverts, word of mouth), as well as via the Internet, to obtain a broad sample of PwMS. Semi-structured interviews were conducted over the telephone, and the questions asked about: the desirability of the Register; what the participants envisaged the Register actually being used for; and what they hoped the Register could be used for. The majority of individuals' points postulated that a UK MS Register would be useful, but a range of potential concerns were identified by the sample, such as security, accessibility for all PwMS, and the validity of self-report data. Analysis of the responses revealed a difference between what PwMS thought the Register would be used for, and how they wanted it to be used, particularly in relation to a desired social contact, exchange, and networking function. The security and accessibility of the website, the validity of the data, and mismatches between the expected and actual uses, are all issues of importance in the development of e-health tools, if PwMS are to be successfully engaged over time. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Quality of life in multiple sclerosis (MS) and role of fatigue, depression, anxiety, and stress: A bicenter study from north of Iran

    PubMed Central

    Salehpoor, Ghasem; Rezaei, Sajjad; Hosseininezhad, Mozaffar

    2014-01-01

    Background: Although studies have demonstrated significant negative relationships between quality of life (QOL), fatigue, and the most common psychological symptoms (depression, anxiety, stress), the main ambiguity of previous studies on QOL is in the relative importance of these predictors. Also, there is lack of adequate knowledge about the actual contribution of each of them in the prediction of QOL dimensions. Thus, the main objective of this study is to assess the role of fatigue, depression, anxiety, and stress in relation to QOL of multiple sclerosis (MS) patients. Materials and Methods: One hundred and sixty-two MS patients completed the questionnaire on demographic variables, and then they were evaluated by the Persian versions of Short-Form Health Survey Questionnaire (SF-36), Fatigue Survey Scale (FSS), and Depression, Anxiety, Stress Scale-21 (DASS-21). Data were analyzed by Pearson correlation coefficient and hierarchical regression. Results: Correlation analysis showed a significant relationship between QOL elements in SF-36 (physical component summary and mental component summary) and depression, fatigue, stress, and anxiety (P < 0.01). Hierarchical regression analysis indicated that among the predictor variables in the final step, fatigue, depression, and anxiety were identified as the physical component summary predictor variables. Anxiety was found to be the most powerful predictor variable amongst all (β = −0.46, P < 0.001). Furthermore, results have shown depression as the only significant mental component summary predictor variable (β = −0.39, P < 0.001). Conclusions: This study has highlighted the role of anxiety, fatigue, and depression in physical dimensions and the role of depression in psychological dimensions of the lives of MS patients. In addition, the findings of this study indirectly suggest that psychological interventions for reducing fatigue, depression, and anxiety can lead to improved QOL of MS patients. PMID:25558256

  12. Quality of life in multiple sclerosis (MS) and role of fatigue, depression, anxiety, and stress: A bicenter study from north of Iran.

    PubMed

    Salehpoor, Ghasem; Rezaei, Sajjad; Hosseininezhad, Mozaffar

    2014-11-01

    Although studies have demonstrated significant negative relationships between quality of life (QOL), fatigue, and the most common psychological symptoms (depression, anxiety, stress), the main ambiguity of previous studies on QOL is in the relative importance of these predictors. Also, there is lack of adequate knowledge about the actual contribution of each of them in the prediction of QOL dimensions. Thus, the main objective of this study is to assess the role of fatigue, depression, anxiety, and stress in relation to QOL of multiple sclerosis (MS) patients. One hundred and sixty-two MS patients completed the questionnaire on demographic variables, and then they were evaluated by the Persian versions of Short-Form Health Survey Questionnaire (SF-36), Fatigue Survey Scale (FSS), and Depression, Anxiety, Stress Scale-21 (DASS-21). Data were analyzed by Pearson correlation coefficient and hierarchical regression. Correlation analysis showed a significant relationship between QOL elements in SF-36 (physical component summary and mental component summary) and depression, fatigue, stress, and anxiety (P < 0.01). Hierarchical regression analysis indicated that among the predictor variables in the final step, fatigue, depression, and anxiety were identified as the physical component summary predictor variables. Anxiety was found to be the most powerful predictor variable amongst all (β = -0.46, P < 0.001). Furthermore, results have shown depression as the only significant mental component summary predictor variable (β = -0.39, P < 0.001). This study has highlighted the role of anxiety, fatigue, and depression in physical dimensions and the role of depression in psychological dimensions of the lives of MS patients. In addition, the findings of this study indirectly suggest that psychological interventions for reducing fatigue, depression, and anxiety can lead to improved QOL of MS patients.

  13. LC coupled to ESI, MALDI and ICP MS - A multiple hyphenation for metalloproteomic studies.

    PubMed

    Coufalíková, Kateřina; Benešová, Iva; Vaculovič, Tomáš; Kanický, Viktor; Preisler, Jan

    2017-05-22

    A new multiple detection arrangement for liquid chromatography (LC) that supplements conventional electrospray ionization (ESI) mass spectrometry (MS) detection with two complementary detection techniques, matrix-assisted laser desorption/ionization (MALDI) MS and substrate-assisted laser desorption inductively coupled plasma (SALD ICP) MS has been developed. The combination of the molecular and elemental detectors in a single separation run is accomplished by utilizing a commercial MALDI target made of conductive plastic. The proposed platform provides a number of benefits in today's metalloproteomic applications, which are demonstrated by analysis of a metallothionein mixture. To maintain metallothionein complexes, separation is carried out at a neutral pH. The effluent is split; a major portion is directed to ESI MS while the remaining 1.8% fraction is deposited onto a plastic MALDI target. Dried droplets are overlaid with MALDI matrix and analysed consecutively by MALDI MS and SALD ICP MS. In the ESI MS spectra, the MT isoform complexes with metals and their stoichiometry are determined; the apoforms are revealed in the MALDI MS spectra. Quantitative determination of metallothionein isoforms is performed via determination of metals in the complexes of the individual protein isoforms using SALD ICP MS. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Bundling Post-Acute Care Services into MS-DRG Payments

    PubMed Central

    Vertrees, James C.; Averill, Richard F.; Eisenhandler, Jon; Quain, Anthony; Switalski, James

    2013-01-01

    Objective A bundled hospital payment system that encompasses both acute and post-acute care has been proposed as a means of creating financial incentives in the Medicare fee-for-service system to foster care coordination and to improve the current disorganized system of post care. The objective of this study was to evaluate the statistical stability of alternative designs of a hospital payment system that includes post-acute care services to determine the feasibility of using a combined hospital and post-acute care bundle as a unit of payment. Methods The Medicare Severity-Diagnosis Related Groups (MS-DRGs) were subdivided into clinical subclasses that measured a patient's chronic illness burden to test whether a patient's chronic illness burden had a substantial impact on post-acute care expenditures. Using Medicare data the statistical performance of the MS-DRGs with and without the chronic illness subclasses was evaluated across a wide range of post-acute care windows and combinations of post-acute care service bundles using both submitted charges and Medicare payments. Results The statistical performance of the MS-DRGs as measured by R2 was consistently better when the chronic illness subclasses are included indicating that MS-DRGs by themselves are an inadequate unit of payment for post-acute care payment bundles. In general, R2 values increased as the post-acute care window length increased and decreased as more services were added to the post-acute care bundle. Discussion The study results suggest that it is feasible to develop a payment system that incorporates significant post-acute care services into the MS-DRG inpatient payment bundle. This expansion of the basic DRG payment approach can provide a strong financial incentive for providers to better coordinate care potentially leading to improved efficiency and outcome quality. PMID:24753970

  15. Visualization of LC-MS/MS proteomics data in MaxQuant.

    PubMed

    Tyanova, Stefka; Temu, Tikira; Carlson, Arthur; Sinitcyn, Pavel; Mann, Matthias; Cox, Juergen

    2015-04-01

    Modern software platforms enable the analysis of shotgun proteomics data in an automated fashion resulting in high quality identification and quantification results. Additional understanding of the underlying data can be gained with the help of advanced visualization tools that allow for easy navigation through large LC-MS/MS datasets potentially consisting of terabytes of raw data. The updated MaxQuant version has a map navigation component that steers the users through mass and retention time-dependent mass spectrometric signals. It can be used to monitor a peptide feature used in label-free quantification over many LC-MS runs and visualize it with advanced 3D graphic models. An expert annotation system aids the interpretation of the MS/MS spectra used for the identification of these peptide features. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Determination of armepavine in mouse blood by UPLC-MS/MS and its application to pharmacokinetic study.

    PubMed

    Geng, Peiwu; Luo, Jun; Weng, Ziwei; Fan, Zhehua; Zhang, Bin; Ma, Jianshe; Wang, Xianqin; Zhang, Meiling

    2018-05-03

    The purpose of this study was to develop an ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method to determine armepavine in mouse blood. Nuciferine was used as internal standard. Chromatographic separation was performed on a UPLC BEH (2.1 × 50 mm, 1.7 μm) column with a gradient elution of acetonitrile and 10 mmol/L ammonium acetate solution (containing 0.1% formic acid). The quantitative analysis was conducted in multiple reaction monitoring mode with m/z 314.1 → 106.9 for armepavine and m/z 296.2 → 265.1 for nuciferine. Calibration curves were linear (r > 0.995) over the concentration range 1-1000 ng/mL in mouse blood with a lowest limit of quantitation of 1 ng/mL. The intra- and inter-day precisions of armepavine in mouse were < 13.5 and 10.8%, respectively. The accuracy ranged between 86.8 and 103.3%. Meanwhile, the average recovery was >70.7% and the matrix effect was within the range 109.5-113.7%. All of the obtained data confirmed the satisfactory sensitivity and selectivity of the developed method which was then successfully applied to evaluate the pharmacokinetic behavior of armepavine in mouse for the first time. The bioavailability of armepavine in mouse was calculated to be 11.3%. Copyright © 2018 John Wiley & Sons, Ltd.

  17. Metabolic profile of naringenin in the stomach and colon using liquid chromatography/electrospray ionization linear ion trap quadrupole-Orbitrap-mass spectrometry (LC-ESI-LTQ-Orbitrap-MS) and LC-ESI-MS/MS.

    PubMed

    Orrego-Lagarón, Naiara; Vallverdú-Queralt, Anna; Martínez-Huélamo, Miriam; Lamuela-Raventos, Rosa M; Escribano-Ferrer, Elvira

    2016-02-20

    Several biological activities (antioxidant, anti-inflammatory, anticarcinogenic) are attributed to naringenin (NAR)-a predominant flavonoid of citrus fruit and tomato-despite its low bioavailability after ingestion. NAR undergoes extensive metabolism when crossing the gastrointestinal tract, resulting in enteric, hepatic and microbial metabolites, some of them with recognized beneficial effects on human health. This study sought to provide new insights into the metabolism of NAR in regions of the gastrointestinal tract where it has been less studied: the stomach and colon. With this purpose, liquid chromatography coupled with an electrospray ionization hybrid linear ion trap quadrupole Orbitrap mass spectrometry technique (LC-ESI-LTQ-Orbitrap-MS) was used for an accurate identification of NAR metabolites, and liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) on a triple quadrupole was used for their identification and quantification. The combination of both analytical techniques provided a broader metabolic profile of NAR. As far as we know, this is the first in-depth metabolic profiling study of NAR in the stomach of mice. Three of the metabolites determined using the LC-LTQ-Orbitrap could not be identified by LC-ESI-MS/MS in stomach perfusion samples: apigenin, 3-(4-hydroxyphenyl) propionic acid and phloroglucinol. The number of colonic metabolites determined using the LTQ-Orbitrap-MS was more than twice the number identified by LC-ESI-MS/MS. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. LC-MS/MS method for the determination of haemanthamine in rat plasma, bile and urine and its application to a pilot pharmacokinetic study.

    PubMed

    Hroch, Miloš; Mičuda, Stanislav; Havelek, Radim; Cermanová, Jolana; Cahlíková, Lucie; Hošťálková, Anna; Hulcová, Daniela; Řezáčová, Martina

    2016-07-01

    Evidence gathered in various studies points to the fact that haemanthamine, an isoquinoline alkaloid, has multiple medicinally interesting characteristics, including antitumor, antileukemic, antioxidant, antiviral, anticonvulsant and antimalarial activity. This work presents, for the first time, a universal LC-MS/MS method for analysis of haemanthamine in plasma, bile and urine which has been verified in a pilot pharmacokinetic experiment on rats. Chromatographic separation was performed on a pentafluorophenyl core-shell column in gradient elution mode with a mobile phase consisting of acetonitrile-methanol-ammonium formate buffer. A sample preparation based on liquid-liquid extraction with methyl tert-butyl ether was employed with ambelline used as an internal standard. Quantification was performed using LC-MS-ESI(+) in Selected Reaction Monitoring mode. The method was validated according to the European Medicines Agency guideline in a concentration range of 0.1-10 μmol/L in plasma, bile and urine. The concentration-time profiles of haemanthamine in plasma, bile and urine after a single i.v. bolus of 10 mg/kg have been described for the first time. The presented study addresses the lack of information on haemanthamine pharmacokinetics and also introduces a new universal method of haemanthamine analysis in complex biological matrices. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Stars of type MS with evidence of white dwarf companions. [IUE, Main Sequence (MS)

    NASA Technical Reports Server (NTRS)

    Peery, Benjamin F., Jr.

    1986-01-01

    A search for white dwarf companions of MS-type stars was conducted, using IUE. The overendowments of these stars in typical S-process nuclides suggest that they, like the Ba II stars, may owe their peculiar compositions to earlier mass transfer. Short-wavelength IUE spectra show striking emission line variability in HD35155, HD61913, and 4 Ori; HD35155 and 4 Ori show evidence of white dwarf companions.

  20. A sensitive and specific LC-MS/MS method for rapid diagnosis of Niemann-Pick C1 disease from human plasma[S

    PubMed Central

    Jiang, Xuntian; Sidhu, Rohini; Porter, Forbes D.; Yanjanin, Nicole M.; Speak, Anneliese O.; te Vruchte, Danielle Taylor; Platt, Frances M.; Fujiwara, Hideji; Scherrer, David E.; Zhang, Jessie; Dietzen, Dennis J.; Schaffer, Jean E.; Ory, Daniel S.

    2011-01-01

    Niemann-Pick type C1 (NPC1) disease is a rare, progressively fatal neurodegenerative disease for which there are no FDA-approved therapies. A major barrier to developing new therapies for this disorder has been the lack of a sensitive and noninvasive diagnostic test. Recently, we demonstrated that two cholesterol oxidation products, specifically cholestane-3β,5α,6β-triol (3β,5α,6β-triol) and 7-ketocholesterol (7-KC), were markedly increased in the plasma of human NPC1 subjects, suggesting a role for these oxysterols in diagnosis of NPC1 disease and evaluation of therapeutics in clinical trials. In the present study, we describe the development of a sensitive and specific LC-MS/MS method for quantifying 3β,5α,6β-triol and 7-KC human plasma after derivatization with N,N-dimethylglycine. We show that dimethylglycine derivatization successfully enhanced the ionization and fragmentation of 3β,5α,6β-triol and 7-KC for mass spectrometric detection of the oxysterol species in human plasma. The oxysterol dimethylglycinates were resolved with high sensitivity and selectivity, and enabled accurate quantification of 3β,5α,6β-triol and 7-KC concentrations in human plasma. The LC-MS/MS assay was able to discriminate with high sensitivity and specificity between control and NPC1 subjects, and offers for the first time a noninvasive, rapid, and highly sensitive method for diagnosis of NPC1 disease. PMID:21518695

  1. A quantitative LC-MS/MS method for determination of thiazolidinedione mitoNEET ligand NL-1 in mouse serum suitable for pharmacokinetic studies.

    PubMed

    Pedada, Kiran K; Zhou, Xiang; Jogiraju, Harini; Carroll, Richard T; Geldenhuys, Werner J; Lin, Li; Anderson, David J

    2014-01-15

    Thiazolidinedione (TZD) compounds have shown promise as antidiabetic, antibiotics, antifungal and neuroprotective agents. The mitochondrial effect of a novel mitoNEET ligand, NL-1 {5-[(3,5-di-tert-butyl-4-hydroxyphenyl)methyl]-1,3-thiazolidine-2,4-dione}, and other TZD compounds, is a newly proposed mechanism for the neuroprotective action of these TZD compounds. In this work, a sensitive LC-MS/MS assay has been developed and validated for quantification of NL-1 in mouse serum. Sample preparation involved an acetonitrile protein precipitation procedure with addition of an internal standard NL-2 {5-[(4-hydroxy-3,5-dimethyl-phenyl)methyl]thiazolidine-2,4-dione}. LC-MS/MS analysis utilized a Columbus C-18 HPLC column (2mm×50mm, 5μm). Chromatography employed a multiple step gradient program that featured a steep linear gradient (25-95% in 0.5min) of 15μM ammonium acetate (additive for eliminating carry-over) in 2% methanol mixing with increasing proportions of 100% methanol. The HPLC was interfaced to a QTrap 5500 mass spectrometer (AB Sciex) equipped with an electrospray ionization source used in a negative ionization mode. Multiple reaction monitoring (MRM) of m/z 334→263 for NL-1 and m/z 250→179 for NL-2 was done. The method had a linear range of at least 1-100ng/mL in serum. The intra-assay and inter-assay percent coefficient of variation (%CV) were less than 4% and accuracies (%RE) ranged from -2.7% to 2.0%. The analytical procedure gave 96-115% absolute extraction recovery of NL-1. The relative matrix effect was measured and found to be insignificant. The analyte in serum was confirmed to be stable during storage and treatment. The method is suitable for pharmacokinetic (PK) studies of the parent drug NL-1 based on the preliminary serum results from dosed NL-1 mouse studies. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Identifying inaccuracy of MS Project using system analysis

    NASA Astrophysics Data System (ADS)

    Fachrurrazi; Husin, Saiful; Malahayati, Nurul; Irzaidi

    2018-05-01

    The problem encountered in project owner’s financial accounting report is the difference in total project costs of MS Project to the Indonesian Standard (Standard Indonesia Standard / Cost Estimating Standard Book of Indonesia). It is one of the MS Project problems concerning to its cost accuracy, so cost data cannot be used in an integrated way for all project components. This study focuses on finding the causes of inaccuracy of the MS Projects. The aim of this study, which is operationally, are: (i) identifying cost analysis procedures for both current methods (SNI) and MS Project; (ii) identifying cost bias in each element of the cost analysis procedure; and (iii) analysing the cost differences (cost bias) in each element to identify what the cause of inaccuracies in MS Project toward SNI is. The method in this study is comparing for both the system analysis of MS Project and SNI. The results are: (i) MS Project system in Work of Resources element has limitation for two decimal digits only, have led to its inaccuracy. Where the Work of Resources (referred to as effort) in MS Project represents multiplication between the Quantities of Activities and Requirements of resources in SNI; (ii) MS Project and SNI have differences in the costing methods (the cost estimation methods), in which the SNI uses the Quantity-Based Costing (QBC), meanwhile MS Project uses the Time-Based Costing (TBC). Based on this research, we recommend to the contractors who use SNI should make an adjustment for Work of Resources in MS Project (with correction index) so that it can be used in an integrated way to the project owner’s financial accounting system. Further research will conduct for improvement the MS Project as an integrated tool toward all part of the project participant.

  3. Determination of a PDE4 inhibitor Hemay005 in human plasma and urine by UPLC-MS/MS and its application to a PK study.

    PubMed

    Liu, Xuemei; Chen, Rui; Zeng, Guanghuai; Gao, Ying; Liu, Xiuping; Zhang, Donglei; Hu, Pei; Wang, Hongyun; Jiang, Ji

    2018-06-04

    Hemay005 is a novel small-molecule inhibitor of phosphodiesterase-4 developed for the treatment of psoriasis. Measurement of Hemay005 in biological samples is critical for evaluation of its pharmacokinetics in clinical studies. Methodology & results: Plasma and urine samples were extracted and then chromatographed on an Acquity UPLC HSS T3 column with a gradient elution. Detection was performed on a Xevo TQ-S tandem mass spectrometer using negative ESI. For the first time, a sensitive and robust ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established and validated for the quantitative determination of Hemay005 in human plasma and urine, and it was successfully applied to evaluate the pharmacokinetics of Hemay005 in healthy subjects in a first-in-human study.

  4. Glycoproteins Enrichment and LC-MS/MS Glycoproteomics in Central Nervous System Applications.

    PubMed

    Zhu, Rui; Song, Ehwang; Hussein, Ahmed; Kobeissy, Firas H; Mechref, Yehia

    2017-01-01

    Proteins and glycoproteins play important biological roles in central nervous systems (CNS). Qualitative and quantitative evaluation of proteins and glycoproteins expression in CNS is critical to reveal the inherent biomolecular mechanism of CNS diseases. This chapter describes proteomic and glycoproteomic approaches based on liquid chromatography/tandem mass spectrometry (LC-MS or LC-MS/MS) for the qualitative and quantitative assessment of proteins and glycoproteins expressed in CNS. Proteins and glycoproteins, extracted by a mass spectrometry friendly surfactant from CNS samples, were subjected to enzymatic (tryptic) digestion and three down-stream analyses: (1) a nano LC system coupled with a high-resolution MS instrument to achieve qualitative proteomic profile, (2) a nano LC system combined with a triple quadrupole MS to quantify identified proteins, and (3) glycoprotein enrichment prior to LC-MS/MS analysis. Enrichment techniques can be applied to improve coverage of low abundant glycopeptides/glycoproteins. An example described in this chapter is hydrophilic interaction liquid chromatographic (HILIC) enrichment to capture glycopeptides, allowing efficient removal of peptides. The combination of three LC-MS/MS-based approaches is capable of the investigation of large-scale proteins and glycoproteins from CNS with an in-depth coverage, thus offering a full view of proteins and glycoproteins changes in CNS.

  5. Randomized double-blinded pilot clinical study of the antidiabetic activity of Balanites aegyptiaca and UPLC-ESI-MS/MS identification of its metabolites.

    PubMed

    Rashad, Hend; Metwally, Fateheya M; Ezzat, Shahira M; Salama, Maha M; Hasheesh, Adel; Abdel Motaal, Amira

    2017-12-01

    Balanites aegyptiaca Del. (Zygophyllaceae) fruits are traditionally known for the treatment of hyperglycaemia. Several in vitro and in vivo studies proposed some mechanisms of action. However, clinical trials in human beings were never reported to date. To investigate the antidiabetic efficacy of the 70% ethanol extract of the pericarps of B. aegyptiaca (BE) within a nutritional intervention in elderly people. Ultra-performance electrospray ionization-mass spectroscopy (UPLC-ESI-MS/MS) analysis was used for metabolic profiling of BE which was incorporated in hard gelatine capsules (400 mg/day) and tested on 30 type 2 diabetes (T2D) Egyptian patients for 8 weeks. According to sex, age and body mass index participants were divided into two equivalent groups, placebo and treatment. Thirteen compounds were identified in BE using UPLC-ESI-MS/MS analysis among which five steroidal saponins, seven phenolic compounds and a sterol glucoside. At the end of the 8-week treatment, the treated group showed 26.88% decrease in 2 h postprandial plasma glucose relative to 2.6% increase in the placebo group, while fasting plasma glucose was reduced to 10.3%. Treatment with BE capsules for 8 weeks produced significant reduction in the plasma triglyceride, total cholesterol and low-density lipoprotein cholesterol by 9.0, 12.76 and 21.35%, respectively, with 29.8% increase in the high-density lipoprotein cholesterol. Plasma alanine transaminase and aspartate transaminase were reduced by 42.6 and 43.3%, respectively. Administration of the BE capsules to T2D resulted in significant improvements in the glycaemic markers and the lipid profile, without adverse effects or hypoglycaemia.

  6. Determination of aniracetam's main metabolite, N-anisoyl-GABA, in human plasma by LC-MS/MS and its application to a pharmacokinetic study.

    PubMed

    Cai, Shuang; Wang, Lei

    2012-05-15

    A simple and rapid high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method has been developed and validated for the determination of 4-p-anisamidobutyric acid (ABA; or N-anysoyl-γ-aminobutiryc acid, N-anisoyl-GABA), a major active metabolite of aniracetam, in human plasma. After protein precipitation of plasma sample with methanol, ABA and the internal standard lisinopril were separated on a Venusil ASB C₁₈ column at 25 °C. The mobile phase consisted of methanol-ammonium acetate (10 mmol/L) (30:70, v/v). The detection was performed on a triple quadrupole tandem mass spectrometer with an ESI source in negative ion mode. Multiple reaction monitoring (MRM) using the precursor→product ion combinations of m/z 235.8→m/z 106.6, and m/z 403.8→m/z 113.6 was used to quantify ABA and lisinopril, respectively. This is the first LC-MS/MS method for ABA with advantages of short analysis time (4.5 min per sample run) and high selectivity attributable to the MRM detection and optimized HPLC conditions. The response was linear in a concentration range of 0.0485-19.4 μg/mL in plasma. The extraction recovery of ABA was between 89.1% and 100.7%. The precision (RSD) and accuracy (RE) of the method were evaluated to be within 7.3% and from 2.5% to 6.9%. The validated method has been applied to the pharmacokinetic study after a single oral administration of aniracetam dispersible tablets to human beings. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Physics Courses--Some Suggested Case Studies

    ERIC Educational Resources Information Center

    Swetman, T. P.

    1972-01-01

    To communicate the relevance and excitement of science activity to students, the use of more imaginative, and even openly speculative, case studies in physics courses is suggested. Some useful examples are Magnetic Monopoles, Constants, Black Holes, Antimatter, Zero Mass Particles, Tachyons, and the Bootstrap Hypothesis. (DF)

  8. Interlaboratory Study Characterizing a Yeast Performance Standard for Benchmarking LC-MS Platform Performance*

    PubMed Central

    Paulovich, Amanda G.; Billheimer, Dean; Ham, Amy-Joan L.; Vega-Montoto, Lorenzo; Rudnick, Paul A.; Tabb, David L.; Wang, Pei; Blackman, Ronald K.; Bunk, David M.; Cardasis, Helene L.; Clauser, Karl R.; Kinsinger, Christopher R.; Schilling, Birgit; Tegeler, Tony J.; Variyath, Asokan Mulayath; Wang, Mu; Whiteaker, Jeffrey R.; Zimmerman, Lisa J.; Fenyo, David; Carr, Steven A.; Fisher, Susan J.; Gibson, Bradford W.; Mesri, Mehdi; Neubert, Thomas A.; Regnier, Fred E.; Rodriguez, Henry; Spiegelman, Cliff; Stein, Stephen E.; Tempst, Paul; Liebler, Daniel C.

    2010-01-01

    Optimal performance of LC-MS/MS platforms is critical to generating high quality proteomics data. Although individual laboratories have developed quality control samples, there is no widely available performance standard of biological complexity (and associated reference data sets) for benchmarking of platform performance for analysis of complex biological proteomes across different laboratories in the community. Individual preparations of the yeast Saccharomyces cerevisiae proteome have been used extensively by laboratories in the proteomics community to characterize LC-MS platform performance. The yeast proteome is uniquely attractive as a performance standard because it is the most extensively characterized complex biological proteome and the only one associated with several large scale studies estimating the abundance of all detectable proteins. In this study, we describe a standard operating protocol for large scale production of the yeast performance standard and offer aliquots to the community through the National Institute of Standards and Technology where the yeast proteome is under development as a certified reference material to meet the long term needs of the community. Using a series of metrics that characterize LC-MS performance, we provide a reference data set demonstrating typical performance of commonly used ion trap instrument platforms in expert laboratories; the results provide a basis for laboratories to benchmark their own performance, to improve upon current methods, and to evaluate new technologies. Additionally, we demonstrate how the yeast reference, spiked with human proteins, can be used to benchmark the power of proteomics platforms for detection of differentially expressed proteins at different levels of concentration in a complex matrix, thereby providing a metric to evaluate and minimize preanalytical and analytical variation in comparative proteomics experiments. PMID:19858499

  9. ESI-MS, ESI-MS/MS fingerprint and LC-ESI-MS analysis of proathocyanidins from Bursera simaruba Sarg bark.

    PubMed

    Maldini, Mariateresa; Montoro, Paola; Piacente, Sonia; Pizza, Cosimo

    2009-12-01

    Direct flow injection/electrospray ionization/ion trap tandem mass spectrometry was used to investigate the presence of proanthocyanidins (PAs) in the methanolic extract of B. simaruba bark. Additionally, an LC-ESI-MS qualitative study was performed by using a monolithic stationary phase. The fragmentation pattern obtained evidenced the presence in B. simaruba bark of PAs belonging to the series of polymers of epicatechin, along with their glycosilated derivatives.

  10. A UPLC-MS/MS method for analysis of vancomycin in human cerebrospinal fluid and comparison with the chemiluminescence immunoassay.

    PubMed

    Mei, Shenghui; Wang, Jiaqing; Zhu, Leting; Chen, Ruiling; Li, Xingang; Chen, Kai; Chen, Guangqiang; Zhou, Jianxin; Wang, Qiang; Zhao, Zhigang

    2017-08-01

    Vancomycin (VCM) is clinically used in treating patients with postoperative intracranial infections. The cerebrospinal fluid (CSF) concentration of VCM varies greatly among patients. To guide the dosage regimens, monitoring of VCM in CSF is needed. However a method for analysis of VCM in human CSF is lacking. An ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for analysis of VCM in human CSF, and the agreement of UPLC-MS/MS and chemiluminescence immunoassay (CLIA) in the analysis of CSF VCM was evaluated. The ion transitions were m/z 725.5 > 144.1 for VCM and m/z 455.2 > 308.2 for methotrexate (internal standard). The agreement between UPLC-MS/MS and CLIA was evaluated by Bland-Altman plot in 179 samples. The calibration range of the UPLC-MS/MS method was 1-400 mg/L. The inaccuracy and imprecision were -0.69-10.80% and <4.95%. The internal standard normalized recovery and matrix factor were 86.14-99.31 and 85.84-92.07%, respectively. The measurements of CLIA and UPLC-MS/MS were strongly correlated (r > 0.98). The 95% limit of agreement of the ratio of CLIA to UPLC-MS/MS was 61.66-107.40%. Further studies are warranted to confirm the results. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Sensitivity and proportionality assessment of metabolites from microdose to high dose in rats using LC-MS/MS.

    PubMed

    Ni, Jinsong; Ouyang, Hui; Seto, Carmai; Sakuma, Takeo; Ellis, Robert; Rowe, Josh; Acheampong, Andrew; Welty, Devin; Szekely-Klepser, Gabriella

    2010-03-01

    The objective of this study was to evaluate the sensitivity requirement for LC-MS/MS as an analytical tool to characterize metabolites in plasma and urine at microdoses in rats and to investigate proportionality of metabolite exposure from a microdose of 1.67 µg/kg to a high dose of 5000 µg/kg for atorvastatin, ofloxacin, omeprazole and tamoxifen. Only the glucuronide metabolite of ofloxacin, the hydroxylation metabolite of omeprazole and the hydration metabolite of tamoxifen were characterized in rat plasma at microdose by LC-MS/MS. The exposure of detected metabolites of omeprazole and tamoxifen appeared to increase in a nonproportional manner with increasing doses. Exposure of ortho- and para-hydroxyatorvastatin, but not atorvastatin and lactone, increased proportionally with increasing doses. LC-MS/MS has demonstrated its usefulness for detecting and characterizing the major metabolites in plasma and urine at microdosing levels in rats. The exposure of metabolites at microdose could not simply be used to predict their exposure at higher doses.

  12. A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS

    DTIC Science & Technology

    2017-10-01

    AWARD NUMBER: W81XWH-15-1-0654 TITLE: A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS...valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE Oct 2017 2. REPORT TYPE Annual 3. DATES COVERED 30...Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT

  13. A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS

    DTIC Science & Technology

    2016-10-01

    AWARD NUMBER: W81XWH-15-1-0653 TITLE: A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS...Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...compare the gut microbiome of subjects with RMS and PPMS. Major Task 1: To seek and obtain HRPO approval Major Task 2: Identification and

  14. A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS

    DTIC Science & Technology

    2016-10-01

    AWARD NUMBER: W81XWH-15-1-0654 TITLE: A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS...Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...Major Tasks and subtasks: Aim#1: To compare the gut microbiome of subjects with RMS and PPMS. Major Task 1: To seek and obtain HRPO approval Major

  15. A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS

    DTIC Science & Technology

    2016-10-01

    AWARD NUMBER: W81XWH-15-1-0652 TITLE: A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS...0652 A Multidisciplinary Approach to Study the Role of the Gut Microbiome in Relapsing and Progressive MS 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...SOW, each Aim was subdivided into Major Tasks and subtasks: Aim#1: To compare the gut microbiome of subjects with RMS and PPMS. Major Task 1

  16. pDeep: Predicting MS/MS Spectra of Peptides with Deep Learning.

    PubMed

    Zhou, Xie-Xuan; Zeng, Wen-Feng; Chi, Hao; Luo, Chunjie; Liu, Chao; Zhan, Jianfeng; He, Si-Min; Zhang, Zhifei

    2017-12-05

    In tandem mass spectrometry (MS/MS)-based proteomics, search engines rely on comparison between an experimental MS/MS spectrum and the theoretical spectra of the candidate peptides. Hence, accurate prediction of the theoretical spectra of peptides appears to be particularly important. Here, we present pDeep, a deep neural network-based model for the spectrum prediction of peptides. Using the bidirectional long short-term memory (BiLSTM), pDeep can predict higher-energy collisional dissociation, electron-transfer dissociation, and electron-transfer and higher-energy collision dissociation MS/MS spectra of peptides with >0.9 median Pearson correlation coefficients. Further, we showed that intermediate layer of the neural network could reveal physicochemical properties of amino acids, for example the similarities of fragmentation behaviors between amino acids. We also showed the potential of pDeep to distinguish extremely similar peptides (peptides that contain isobaric amino acids, for example, GG = N, AG = Q, or even I = L), which were very difficult to distinguish using traditional search engines.

  17. Pharmacokinetic studies of a novel trioxane antimalarial (99/411) in rats and monkeys using LC-MS/MS.

    PubMed

    Pandey, Saurabh; Gautam, Nagsen; Kushwaha, Hari Narayan; Singh, Shio Kumar

    2016-12-01

    The pharmacokinetic profile of 99/411, a novel anti-malarial drug, was established in rats (12 mg/kg of body weight) and monkeys (20 mg/kg of body weight). Following oral administration, the presence of 99/411 was rapidly determined in rat plasma, tissues, urine, feces and monkey plasma using a validated LC-MS/MS method. The tissue distribution studies in rats indicated that the drug was partially distributed in all major tissues and plasma, and peak concentration levels were achieved within 0.5-4 h. Area under the curve in different rat tissues and plasma was found in order of blood > lung > intestine > heart > muscle > brain > kidney > spleen > liver. The total recoveries (within 86 h) of 99/411 were <0.0017% and <0.08% in urine and feces, respectively. The peak plasma concentration was 3499 ng/mL in rats after ~2 h of oral administration and 697-767 ng/mL in monkeys after ~6 h of oral administration. No plasma accumulation was observed in both male and female monkeys, even after multiple dosing. The preclinical pharmacokinetic profile and tissue distribution data are expected to assist in future clinical explorations of 99/411 as a promising anti-malarial agent. Copyright © 2016 John Wiley & Sons, Ltd.

  18. A robust, sensitive assay for genomic uracil determination by LC/MS/MS reveals lower levels than previously reported.

    PubMed

    Galashevskaya, Anastasia; Sarno, Antonio; Vågbø, Cathrine B; Aas, Per A; Hagen, Lars; Slupphaug, Geir; Krokan, Hans E

    2013-09-01

    Considerable progress has been made in understanding the origins of genomic uracil and its role in genome stability and host defense; however, the main question concerning the basal level of uracil in DNA remains disputed. Results from assays designed to quantify genomic uracil vary by almost three orders of magnitude. To address the issues leading to this inconsistency, we explored possible shortcomings with existing methods and developed a sensitive LC/MS/MS-based method for the absolute quantification of genomic 2'-deoxyuridine (dUrd). To this end, DNA was enzymatically hydrolyzed to 2'-deoxyribonucleosides and dUrd was purified in a preparative HPLC step and analyzed by LC/MS/MS. The standard curve was linear over four orders of magnitude with a quantification limit of 5 fmol dUrd. Control samples demonstrated high inter-experimental accuracy (94.3%) and precision (CV 9.7%). An alternative method that employed UNG2 to excise uracil from DNA for LC/MS/MS analysis gave similar results, but the intra-assay variability was significantly greater. We quantified genomic dUrd in Ung(+/+) and Ung(-/-) mouse embryonic fibroblasts and human lymphoblastoid cell lines carrying UNG mutations. DNA-dUrd is 5-fold higher in Ung(-/-) than in Ung(+/+) fibroblasts and 11-fold higher in UNG2 dysfunctional than in UNG2 functional lymphoblastoid cells. We report approximately 400-600 dUrd per human or murine genome in repair-proficient cells, which is lower than results using other methods and suggests that genomic uracil levels may have previously been overestimated. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  19. A novel isoflavone profiling method based on UPLC-PDA-ESI-MS.

    PubMed

    Zhang, Shuang; Zheng, Zong-Ping; Zeng, Mao-Mao; He, Zhi-Yong; Tao, Guan-Jun; Qin, Fang; Chen, Jie

    2017-03-15

    A novel non-targeted isoflavone profiling method was developed using the diagnostic fragment-ion-based extension strategy, based on ultra-high performance liquid chromatography coupled with photo-diode array detector and electrospray ionization-mass spectrometry (UPLC-PDA-ESI-MS). 16 types of isoflavones were obtained in positive mode, but only 12 were obtained in negative mode due to the absence of precursor ions. Malonyldaidzin and malonylgenistin glycosylated at the 4'-O position or malonylated at the 4″-O position of glucose were indicated by their retention behavior and fragmentation pattern. Three possible quantification methods in one run based on UPLC-PDA and UPLC-ESI-MS were validated and compared, suggesting that methods based on UPLC-ESI-MS possess remarkable selectivity and sensitivity. Impermissible quantitative deviations induced by the linearity calibration with 400-fold dynamic range was observed for the first time and was recalibrated with a 20-fold dynamic range. These results suggest that isoflavones and their stereoisomers can be simultaneously determined by positive-ion UPLC-ESI-MS in soymilk. Copyright © 2016. Published by Elsevier Ltd.

  20. Improved simultaneous quantitation of candesartan and hydrochlorthiazide in human plasma by UPLC-MS/MS and its application in bioequivalence studies.

    PubMed

    Singh, Bhupinder; Lokhandae, Rama S; Dwivedi, Ashish; Sharma, Sandeep; Dubey, Naveen

    2014-04-01

    A validated ultra-performance liquid chromatography mass spectrometric method (UPLC-MS/MS) was used for the simultaneous quantitation of candesartan (CN) and hydrochlorothiazide (HCT) in human plasma. The analysis was performed on UPLC-MS/MS system using turbo ion spray interface. Negative ions were measured in multiple reaction monitoring (MRM) mode. The analytes were extracted using a liquid-liquid extraction (LLE) method by using 0.1 mL of plasma volume. The lower limit of quantitation for CN and HCT was 1.00 ng/mL whereas the upper limit of quantitation was 499.15 ng/mL and 601.61 ng/mL for CN and HCT respectively. CN d 4 and HCT- 13 Cd 2 were used as the internal standards for CN and HCT respectively. The chromatography was achieved within 2.0 min run time using a C18 Phenomenex, Gemini NX (100 mm×4.6 mm, 5 µm) column with organic mixture:buffer solution (80:20, v/v) at a flow rate of 0.800 mL/min. The method has been successfully applied to establish the bioequivalence of candesartan cilexetil (CNC) and HCT immediate release tablets with reference product in human subjects.

  1. Development and validation of a LC-MS/MS method for quantitation of fosfomycin - Application to in vitro antimicrobial resistance study using hollow-fiber infection model.

    PubMed

    Gandhi, Adarsh; Matta, Murali; Garimella, Narayana; Zere, Tesfalem; Weaver, James

    2018-06-01

    Extensive use and misuse of antibiotics over the past 50 years has contributed to the emergence and spread of antibiotic-resistant bacterial strains, rendering them as a global health concern. To address this issue, a dynamic in vitro hollow-fiber system, which mimics the in vivo environment more closely than the static model, was used to study the emergence of bacterial resistance of Escherichia coli against fosfomycin (FOS). To aid in this endeavor we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for quantitative analysis of FOS in lysogeny broth. FOS was resolved on a Kinetex HILIC (2.1 × 50 mm, 2.6 μm) column with 2 mm ammonium acetate (pH 4.76) and acetonitrile as mobile phase within 3 min. Multiple reaction monitoring was used to acquire data on a triple quadrupole mass spectrometer. The assay was linear from 1 to 1000 μg/mL. Inter- and intra-assay precision and accuracy were <15% and between ±85 and 115% respectively. No significant matrix effect was observed when corrected with the internal standard. FOS was stable for up to 24 h at room temperature, up to three freeze-thaw cycles and up to 24 h when stored at 4°C in the autosampler. In vitro experimental data were similar to the simulated plasma pharmacokinetic data, further confirming the appropriateness of the experimental design to quantitate antibiotics and study occurrence of antimicrobial resistance in real time. The validated LC-MS/MS assays for quantitative determination of FOS in lysogeny broth will help antimicrobial drug resistance studies. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  2. Teaching Bibliometric Analysis and MS/DOS Commands.

    ERIC Educational Resources Information Center

    Dou, Henri; And Others

    1988-01-01

    Outlines the steps involved in bibliometric studies, and demonstrates the ability to execute simple studies on microcomputers by downloading files using only the capability of MS/DOS. Detailed illustrations of the MS/DOS commands used are provided. (eight references) (CLB)

  3. MS2/TOF and LC-MS/TOF studies on toremifene to characterize its forced degradation products.

    PubMed

    Bansal, Gulshan; Maddhesia, Pawan K; Bansal, Yogita

    2011-12-21

    The present study was designed to characterize the possible degradation products of toremifene under varied conditions as prescribed by ICH guidelines Q1A(R2). The forced degradation studies were conducted on toremifene citrate under the conditions of hydrolysis (acidic, basic and neutral), photolysis, oxidation and dry heat. The drug was found unstable to photolysis and hydrolysis in water and acidic media but stable to alkaline hydrolysis, peroxide oxidation and thermal degradation. In total fifteen degradation products (I-XV) were formed, which were resolved from each other and the drug on a C-18 column employing an isocratic elution method. A complete mass fragmentation pattern of the drug was established with the help of LC/ESI-MS/TOF to assist characterization of the degradation products. Of the fifteen products, six products III, IV, VII, VIII, XIV and XV were detected in LC-MS. The molecular masses of III, IV, VII and VIII were found to be the same i.e., 387, while those of XIV and XV were 389 and 403, respectively. Structures of these products were elucidated through comparison of their mass fragmentation patterns with the drug, which were proposed on the basis of accurate masses of the parent and fragment ions. These were characterized as (Z)-2-(2-(dimethylamino)ethyl)-4-(4-hydroxy-1,2-diphenylbut-1-enyl)phenol (III), (E)-2-(2-(dimethylamino)ethyl)-4-(4-hydroxy-1,2-diphenylbut-1-enyl)phenol (IV), (E)-4-(4-(2-(dimethylamino)ethoxy)phenyl)-3,4-diphenylbut-3-en-1-ol (VII), (Z)-4-(4-(2-(dimethylamino)ethoxy)phenyl)-3,4-diphenylbut-3-en-1-ol (VIII), 2-(4-(10-(2-chloroethyl)phenanthren-9-yl)phenoxy)-N-methylethanamine (XIV), and 2-(4-(10-(2-chloroethyl)phenanthren-9-yl)phenoxy)-N,N-dimethylethanamine (XV). Finally, a most plausible mechanistic explanation for degradation of the drug in different chemical environments is also proposed. The results of the study disclose six new degradation related impurities of the drug.

  4. Neuropsychological Training of Attention Improves MS-Related Fatigue: Results of a Randomized, Placebo-Controlled, Double-Blind Pilot Study.

    PubMed

    Flachenecker, Peter; Meissner, Heike; Frey, Rebecca; Guldin, Wolfgang

    2017-01-01

    Attentional deficits may be pathophysiologically relevant in MS-associated fatigue. Thirty MS patients with fatigue and attentional deficits in neuropsychological testing participated in this randomized, placebo-controlled, double-blind trial. The intervention group (IG; n = 14) was treated with 10 h of computerized, specific neuropsychological training performing simple reaction time tasks, whereas the control group (CG; n = 16) also runs through computerized, but unspecific neuropsychological training using tasks without time components. The subjective feeling of fatigue was assessed with the Würzburg Fatigue Inventory for Multiple Sclerosis (WEIMuS) questionnaire, and testing of alertness was used as an objective measure at baseline and after the 2-week study period. Reaction times of alertness were significantly decreased in IG but not CG after 2 weeks. The subjective feeling of fatigue was ameliorated in both groups but more pronounced in IG. Effect sizes were below 0.7 for alertness and WEIMuS scores in CG but large and clinically meaningful in IG for both measures. Our pilot study suggests that neuropsychological training of attention may improve both measures of fatigue. The parallel improvement of attentional deficits and subjective fatigue after specific neuropsychological training support previous findings that fatigue may be at least partially caused by impaired intensity of attention. © 2017 S. Karger AG, Basel.

  5. Adhesive blood microsampling systems for steroid measurement via LC-MS/MS in the rat.

    PubMed

    Heussner, Kirsten; Rauh, Manfred; Cordasic, Nada; Menendez-Castro, Carlos; Huebner, Hanna; Ruebner, Matthias; Schmidt, Marius; Hartner, Andrea; Rascher, Wolfgang; Fahlbusch, Fabian B

    2017-04-01

    Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) allows for the direct analysis of multiple hormones in a single probe with minimal sample volume. Rodent-based animal studies strongly rely on microsampling, such as the dry blood spot (DBS) method. However, DBS suffers the drawback of hematocrit-dependence (non-volumetric). Hence, novel volumetric microsampling techniques were introduced recently, allowing sampling of fixed accurate volumes. We compared these methods for steroid analysis in the rat to improve inter-system comparability. We analyzed steroid levels in blood using the absorptive microsampling devices Whatman® 903 Protein Saver Cards, Noviplex™ Plasma Prep Cards and the Mitra™ Microsampling device and compared the obtained results to the respective EDTA plasma levels. Quantitative steroid analysis was performed via LC-MS/MS. For the determination of the plasma volume factor for each steroid, their levels in pooled blood samples from each human adults and rats (18weeks) were compared and the transferability of these factors was evaluated in a new set of juvenile (21days) and adult (18weeks) rats. Hematocrit was determined concomitantly. Using these approaches, we were unable to apply one single volume factor for each steroid. Instead, plasma volume factors had to be adjusted for the recovery rate of each steroid and device individually. The tested microsampling systems did not allow the use of one single volume factor for adult and juvenile rats based on an unexpectedly strong hematocrit-dependency and other steroid specific (pre-analytic) factors. Our study provides correction factors for LC-MS/MS steroid analysis of volumetric and non-volumetric microsampling systems in comparison to plasma. It argues for thorough analysis of chromatographic effects before the use of novel volumetric systems for steroid analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. LC-MS/MS analysis of uncommon paracetamol metabolites derived through in vitro polymerization and nitration reactions in liquid nitrogen.

    PubMed

    Trettin, Arne; Jordan, Jens; Tsikas, Dimitrios

    2014-09-01

    Paracetamol (acetaminophen, APAP) is a commonly used analgesic drug. Known paracetamol metabolites include the glucuronide, sulfate and mercapturate. N-Acetyl-benzoquinonimine (NAPQI) is considered the toxic intermediate metabolite of paracetamol. In vitro and in vivo studies indicate that paracetamol is also metabolized to additional poorly characterized metabolites. For example, metabolomic studies in urine samples of APAP-treated mice revealed metabolites such as APAP-sulfate-APAP and APAP-S-S-APAP in addition to the classical phase II metabolites. Here, we report on the development and application of LC-MS and LC-MS/MS approaches to study reactions of unlabelled and (2)H-labelled APAP with unlabelled and (15)N-labelled nitrite in aqueous phosphate buffers (pH 7.4) upon their immersion into liquid nitrogen (-196°C). In mechanistic studies, these reactions were also studied in aqueous buffer prepared in (18)O-labelled water. LC-MS and LC-MS/MS analyses were performed on a reverse-phase material (C18) using gradient elution (2mM ammonium acetate/acetonitrile), in positive and negative electrospray mode. We identified a series of APAP metabolites including di-, tri- and tetra-APAP, mono- and di-nitro-APAP and nitric ester of di-APAP. Our study indicates that nitrite induces oxidation, i.e., polymerization and nitration of APAP, when buffered APAP/nitrite solutions are immersed into liquid nitrogen. These reactions are specific for nitrite with respect to nitrate and do not proceed via intermediate formation of NAPQI. Potassium ions and physiological saline but not thiols inhibit nitrite- and shock-freeze-induced reactions of paracetamol. The underlying mechanism likely involves in situ formation of NO2 radicals from nitrite secondary to profound pH reduction (down to pH 1) and disproportionation. Polymeric paracetamol species can be analyzed as pentafluorobenzyl derivatives by LC-MS but not by GC-MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Tissue distribution study of periplocin and its two metabolites in rats by a validated LC-MS/MS method.

    PubMed

    Liu, Huaming; Zhang, Dandan; Tang, Zhidan; Sun, Mengjie; Azietaku, John Teye; Ouyang, Huizi; Chang, Yanxu; Wang, Meng; He, Jun; Gao, Xiumei

    2018-05-29

    Periplocin is a cardiac glycoside and has been used widely in the clinic for its cardiotonic, anti-inflammatory and anti-tumor effects. Though it was taken frequently by oral administration in clinic, there were no reports demonstrated that periplocin could be detected in vivo after an oral administration of periplocin, so it is badly need of searching the characteristic of periplocin in vivo after an oral administration. In this study, a sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to identify and quantify periplocin and its two metabolites in rat tissue after a single dosage of perplocin at 50 mg/kg. The results demonstrated that periplocin and its two metabolites were detected in all of the selected tissues, periplocin could be reach peak concentration quickly after administration, while periplocymarin and periplogenin reached maximum concentration more than 4.83 h after administration. The tissue distribution of analytes tended to be mostly in the liver, and higher analytes concentrations were found in the heart, liver, spleen, lung, kidney, but a small amount of chemical constituents were distributed into the brain. The consequences obtained using this method might provide a meaningful insight for the clinical investigations and applications. This article is protected by copyright. All rights reserved.

  8. Integration of Molecular Networking and In-Silico MS/MS Fragmentation for Natural Products Dereplication.

    PubMed

    Allard, Pierre-Marie; Péresse, Tiphaine; Bisson, Jonathan; Gindro, Katia; Marcourt, Laurence; Pham, Van Cuong; Roussi, Fanny; Litaudon, Marc; Wolfender, Jean-Luc

    2016-03-15

    Dereplication represents a key step for rapidly identifying known secondary metabolites in complex biological matrices. In this context, liquid-chromatography coupled to high resolution mass spectrometry (LC-HRMS) is increasingly used and, via untargeted data-dependent MS/MS experiments, massive amounts of detailed information on the chemical composition of crude extracts can be generated. An efficient exploitation of such data sets requires automated data treatment and access to dedicated fragmentation databases. Various novel bioinformatics approaches such as molecular networking (MN) and in-silico fragmentation tools have emerged recently and provide new perspective for early metabolite identification in natural products (NPs) research. Here we propose an innovative dereplication strategy based on the combination of MN with an extensive in-silico MS/MS fragmentation database of NPs. Using two case studies, we demonstrate that this combined approach offers a powerful tool to navigate through the chemistry of complex NPs extracts, dereplicate metabolites, and annotate analogues of database entries.

  9. Quantitative Determination of Perfluorochemicals and Fluorotelomer Alcohols in Plants from Biosolid-Amended Fields using LC/MS/MS and GC/MS

    EPA Science Inventory

    Analytical methods for determining perfluorochemicals (PFCs) and fluorotelomer alcohols (FTOHs) in plants using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and gas chromatography/mass spectrometry (GC/MS) were developed, and applied to quantify a suite of analytes i...

  10. PER3 VNTR polymorphism in Multiple Sclerosis: A new insight to impact of sleep disturbances in MS.

    PubMed

    Golalipour, Masoud; Maleki, Zahra; Farazmandfar, Touraj; Shahbazi, Majid

    2017-10-01

    Multiple Sclerosis (MS) is a degenerative disease of central nervous system caused by an immune response against the myelin. About half of MS patients suffers from sleep disturbances. The circadian clock genes such as PER3 controls circadian rhythm and sleep. Due to the role of PER3 in sleep disturbances and regulation of immune response, it is possible that PER3 dysregulation increase risk of MS disease. Study groups included 160 MS patients and 160 healthy volunteers. PER3 VNTR polymorphism was evaluated by PCR method. The genotypic and allelic distribution analyzed by chi square test. There was a significant association between genotype PER3 4/4 , and 4-repeat allele with MS disease (p = 0.014 and p < 0.001 respectively). The association analysis of PER3 VNTR polymorphism with gender status among MS group, and MS onset showed that there was a significant correlation between PER3 4/4 genotype with female gender and early onset of MS disease (p = 0.033 and p = 0.028 respectively). Our data suggest that, PER3 4/4 genotype may accelerate the course of disease in MS susceptible individuals. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Volatile compound changes during shelf life of dried Boletus edulis: comparison between SPME-GC-MS and PTR-ToF-MS analysis.

    PubMed

    Aprea, Eugenio; Romano, Andrea; Betta, Emanuela; Biasioli, Franco; Cappellin, Luca; Fanti, Marco; Gasperi, Flavia

    2015-01-01

    Drying process is commonly used to allow long time storage of valuable porcini mushrooms (Boletus edulis). Although considered a stable product dried porcini flavour changes during storage. Monitoring of volatile compounds during shelf life may help to understand the nature of the observed changes. In the present work two mass spectrometric techniques were used to monitor the evolution of volatile compounds during commercial shelf life of dried porcini. Solid phase microextraction (SPME) coupled to gas chromatography - mass spectrometry (GC-MS) allowed the identification of 66 volatile compounds, 36 of which reported for the first time, monitored during the commercial shelf life of dried porcini. Proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS) , a direct injection mass spectrometric technique, was shown to be a fast and sensitive instrument for the general monitoring of volatile compound evolution during storage of dried porcini. Furthermore, PTR-ToF-MS grants access to compounds whose determination would otherwise require lengthy pre-concentration and/or derivatization steps such as ammonia and small volatile amines. The two techniques, both used for the first time to study dried porcini, provided detailed description of time evolution of volatile compounds during shelf life. Alcohols, aldehydes, ketones and monoterpenes diminish during the storage while carboxylic acids, pyrazines, lactones and amines increase. The storage temperature modifies the rate of the observed changes influencing the final quality of the dried porcini. We showed the advantages of both techniques, suggesting a strategy to be adopted to follow time evolution of volatile compounds in food products during shelf life, based on the identification of compounds by GC-MS and the rapid time monitoring by PTR-ToF-MS measurements in order to maximize the advantages of both techniques. Copyright © 2015 John Wiley & Sons, Ltd.

  12. A new LC-MS/MS bioanalytical method for atenolol in human plasma and milk.

    PubMed

    Phyo Lwin, Ei Mon; Gerber, Cobus; Song, Yunmei; Leggett, Catherine; Ritchie, Usha; Turner, Sean; Garg, Sanjay

    2017-04-01

    A new sensitive LC-MS/MS method for the quantification of atenolol in human plasma and milk has been developed for clinical lactation studies. Atenolol and the internal standard, phenazone, were extracted from biological matrices by protein precipitation. A Phenomenex ® C-18 column and gradient chromatographic conditions were used for separation of the analyte, followed by detection with MS. Stability of samples was confirmed for atenolol in human plasma and milk for up to 3 months. Linearity range of 1-800 ng/ml (r 2 = 0.9995), the precision within 15% CV and the recovery of the analyte (80-100% range) were achieved. A new validated analytical method for atenolol in plasma and milk was developed.

  13. Survey of diagnostic and treatment practices for multiple sclerosis (MS) in Europe. Part 2: Progressive MS, paediatric MS, pregnancy and general management.

    PubMed

    Fernández, O; Delvecchio, M; Edan, G; Fredrikson, S; Giovannoni, G; Hartung, H-P; Havrdova, E; Kappos, L; Pozzilli, C; Soerensen, P S; Tackenberg, B; Vermersch, P; Comi, G

    2018-05-01

    The European Charcot Foundation supported the development of a set of surveys to understand current practice patterns for the diagnosis and management of multiple sclerosis (MS) in Europe. Part 2 of the report summarizes survey results related to secondary progressive MS (SPMS), primary progressive MS (PPMS), pregnancy, paediatric MS and overall patient management. A steering committee of MS neurologists developed case- and practice-based questions for two sequential surveys distributed to MS neurologists throughout Europe. Respondents generally favoured changing rather than stopping disease-modifying treatment (DMT) in patients transitioning from relapsing-remitting MS to SPMS, particularly with active disease. Respondents would not initiate DMT in patients with typical PPMS symptoms, although the presence of ≥1 spinal cord or brain gadolinium-enhancing lesion might affect that decision. For patients considering pregnancy, respondents were equally divided on whether to stop treatment before or after conception. Respondents strongly favoured starting DMT in paediatric MS with active disease; recommended treatments included interferon, glatiramer acetate and, in John Cunningham virus negative patients, natalizumab. Additional results regarding practice-based questions and management are summarized. Results of part 2 of the survey of diagnostic and treatment practices for MS in Europe largely mirror results for part 1, with neurologists in general agreement about the treatment and management of SPMS, PPMS, pregnancy and paediatric MS as well as the general management of MS. However, there are also many areas of disagreement, indicating the need for evidence-based recommendations and/or guidelines. © 2018 EAN.

  14. Epidemiology of multiple sclerosis in US veterans: VII. Risk factors for MS.

    PubMed

    Kurtzke, J F; Page, W F

    1997-01-01

    In previous papers of this series, we explored the epidemiology of MS, examining the effects of race, sex, geography, latitude and climate, migration, age at onset, population ancestry, and individual ethnicity on the risk of MS, using an unusually large cohort of MS cases and pre-illness matched controls comprising US veterans of World War II (WWII) and the Korean Conflict (KC). In this paper, we examine primarily the effect of other factors on the risk of MS in this cohort and their relation to those previously studied. We found here that latitude tier of residence at entry into active duty (EAD), years of education, and socioeconomic class (coded from occupation) were similarly associated with MS risk among white men, black men, and white women. Higher levels of each factor showed increased MS risk. Multivariate analyses indicated that for white male WWII subjects an urban address, 9 or more years of education, uncorrected visual acuity less than 20/20 at EAD, a more northern latitude, and a higher proportion of the subject's EAD state population reporting Swedish ancestry each significantly increased the risk of MS. White male KC subjects showed roughly the same patterns, except that uncorrected visual acuity less than 20/20 was associated with lower MS risk (ancestry/ethnicity was not studied). For black male WWII and KC subjects combined, a similar analysis (omitting ancestry/ethnicity) showed that only latitude at EAD and 9 or more years of education were independently associated with a significantly higher MS risk, and for WWII plus KC white women (also without ancestry/ethnicity), only latitude was a significant risk factor in these multivariate analyses. The smaller number of subjects, especially in these last two groups, limited the power to detect statistically significant risks in these last analyses. Similarities to white men of WWII in univariate analyses for all other groups suggest that findings for the former would otherwise apply to the latter

  15. LC-ESI-MS/MS determination of 4-methylpyrazole in dog plasma and its application to a pharmacokinetic study in dogs.

    PubMed

    Chandrasekhar, Devaraj V; Suresh, Ponnayyan Sulochana; Dittakavi, Sreekanth; Hiremath, Rakesh A; Bhamidipati, Ravi Kanth; Richter, Wolfgang; Srinivas, Nuggehally R; Mullangi, Ramesh

    2018-02-01

    A simple, specific, sensitive and rapid LC-ESI-MS/MS method has been developed and validated for the quantification of 4-methylpyrazole in dog plasma using N-methylnicotinamide-d 4 as an internal standard (IS) as per regulatory guidelines. Sample preparation was accomplished through a simple protein precipitation. Chromatographic separation of 4-methylpyrazole and the IS was performed on a monolithic (Chromolith RP 18e ) column using an isocratic mobile phase comprising 0.2% formic acid in water and acetonitrile (20:80, v/v) at a flow rate of 1.0 mL/min. Elution of 4-methylpyrazole and the IS occurred at ~1.60 and 1.56 min, respectively. The total chromatographic run time was 3.2 min. A linear response function was established in the concentration range of 4.96-4955 ng/mL. The intra- and inter-day accuracy and precision were in the ranges 1.81-12.9 and 3.80-11.1%, respectively. This novel method has been applied to a pharmacokinetic study in dogs. Copyright © 2017 John Wiley & Sons, Ltd.

  16. The Role of the Gut Microbiome in Multiple Sclerosis Risk and Progression: Towards Characterization of the "MS Microbiome".

    PubMed

    Pröbstel, Anne-Katrin; Baranzini, Sergio E

    2018-01-01

    Multiple sclerosis (MS) is the prototypic complex disease, in which both genes and the environment contribute to its pathogenesis. To date, > 200 independent loci across the genome have been associated with MS risk. However, these only explain a fraction of the total phenotypic variance, suggesting the possible presence of additional genetic factors, and, most likely, also environmental factors. New DNA sequencing technologies have enabled the sequencing of all kinds of microorganisms, including those living in and around humans (i.e., microbiomes). The study of bacterial populations inhabiting the gut is of particular interest in autoimmune diseases owing to their key role in shaping immune responses. In this review, we address the potential crosstalk between B cells and the gut microbiota, a relevant scenario in light of recently approved anti-B-cell therapies for MS. In addition, we review recent efforts to characterize the gut microbiome in patients with MS and discuss potential challenges and future opportunities. Finally, we describe the international MS microbiome study, a multicenter effort to study a large population of patients with MS and their healthy household partners to define the core MS microbiome, how it is shaped by disease-modifying therapies, and to explore potential therapeutic interventions.

  17. Automated Assignment of MS/MS Cleavable Cross-Links in Protein 3D-Structure Analysis

    NASA Astrophysics Data System (ADS)

    Götze, Michael; Pettelkau, Jens; Fritzsche, Romy; Ihling, Christian H.; Schäfer, Mathias; Sinz, Andrea

    2015-01-01

    CID-MS/MS cleavable cross-linkers hold an enormous potential for an automated analysis of cross-linked products, which is essential for conducting structural proteomics studies. The created characteristic fragment ion patterns can easily be used for an automated assignment and discrimination of cross-linked products. To date, there are only a few software solutions available that make use of these properties, but none allows for an automated analysis of cleavable cross-linked products. The MeroX software fills this gap and presents a powerful tool for protein 3D-structure analysis in combination with MS/MS cleavable cross-linkers. We show that MeroX allows an automatic screening of characteristic fragment ions, considering static and variable peptide modifications, and effectively scores different types of cross-links. No manual input is required for a correct assignment of cross-links and false discovery rates are calculated. The self-explanatory graphical user interface of MeroX provides easy access for an automated cross-link search platform that is compatible with commonly used data file formats, enabling analysis of data originating from different instruments. The combination of an MS/MS cleavable cross-linker with a dedicated software tool for data analysis provides an automated workflow for 3D-structure analysis of proteins. MeroX is available at www.StavroX.com .

  18. Structural Feature Ions for Distinguishing N- and O-Linked Glycan Isomers by LC-ESI-IT MS/MS

    NASA Astrophysics Data System (ADS)

    Everest-Dass, Arun V.; Abrahams, Jodie L.; Kolarich, Daniel; Packer, Nicolle H.; Campbell, Matthew P.

    2013-06-01

    Glycomics is the comprehensive study of glycan expression in an organism, cell, or tissue that relies on effective analytical technologies to understand glycan structure-function relationships. Owing to the macro- and micro-heterogeneity of oligosaccharides, detailed structure characterization has required an orthogonal approach, such as a combination of specific exoglycosidase digestions, LC-MS/MS, and the development of bioinformatic resources to comprehensively profile a complex biological sample. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) has emerged as a key tool in the structural analysis of oligosaccharides because of its high sensitivity, resolution, and robustness. Here, we present a strategy that uses LC-ESI-MS/MS to characterize over 200 N- and O-glycans from human saliva glycoproteins, complemented by sequential exoglycosidase treatment, to further verify the annotated glycan structures. Fragment-specific substructure diagnostic ions were collated from an extensive screen of the literature available on the detailed structural characterization of oligosaccharides and, together with other specific glycan structure feature ions derived from cross-ring and glycosidic-linkage fragmentation, were used to characterize the glycans and differentiate isomers. The availability of such annotated mass spectrometric fragmentation spectral libraries of glycan structures, together with such substructure diagnostic ions, will be key inputs for the future development of the automated elucidation of oligosaccharide structures from MS/MS data.

  19. Simultaneous determination of antidementia drugs in human plasma: procedure transfer from HPLC-MS to UPLC-MS/MS.

    PubMed

    Noetzli, Muriel; Ansermot, Nicolas; Dobrinas, Maria; Eap, Chin B

    2012-05-01

    A previously developed high performance liquid chromatography mass spectrometry (HPLC-MS) procedure for the simultaneous determination of antidementia drugs, including donepezil, galantamine, memantine, rivastigmine and its metabolite NAP 226-90, was transferred to an ultra performance liquid chromatography system coupled to a tandem mass spectrometer (UPLC-MS/MS). The drugs and their internal standards ([(2)H(7)]-donepezil, [(13)C,(2)H(3)]-galantamine, [(13)C(2),(2)H(6)]-memantine, [(2)H(6)]-rivastigmine) were extracted from 250 μL human plasma by protein precipitation with acetonitrile. Chromatographic separation was achieved on a reverse phase column (BEH C18 2.1 mm × 50 mm; 1.7 μm) with a gradient elution of an ammonium acetate buffer at pH 9.3 and acetonitrile at a flow rate of 0.4 mL/min and an overall run time of 4.5 min. The analytes were detected on a tandem quadrupole mass spectrometer operated in positive electrospray ionization mode, and quantification was performed using multiple reaction monitoring. The method was validated according to the recommendations of international guidelines over a calibration range of 1-300 ng/mL for donepezil, galantamine and memantine, and 0.2-50 ng/mL for rivastimgine and NAP 226-90. The trueness (86-108%), repeatability (0.8-8.3%), intermediate precision (2.3-10.9%) and selectivity of the method were found to be satisfactory. Matrix effects variability was inferior to 15% for the analytes and inferior to 5% after correction by internal standards. A method comparison was performed with patients' samples showing similar results between the HPLC-MS and UPLC-MS/MS procedures. Thus, this validated UPLC-MS/MS method allows to reduce the required amount of plasma, to use a simplified sample preparation, and to obtain a higher sensitivity and specificity with a much shortened run-time. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Spearmint R2R3-MYB transcription factor MsMYB negatively regulates monoterpene production and suppresses the expression of geranyl diphosphate synthase large subunit (MsGPPS.LSU).

    PubMed

    Reddy, Vaishnavi Amarr; Wang, Qian; Dhar, Niha; Kumar, Nadimuthu; Venkatesh, Prasanna Nori; Rajan, Chakravarthy; Panicker, Deepa; Sridhar, Vishweshwaran; Mao, Hui-Zhu; Sarojam, Rajani

    2017-09-01

    Many aromatic plants, such as spearmint, produce valuable essential oils in specialized structures called peltate glandular trichomes (PGTs). Understanding the regulatory mechanisms behind the production of these important secondary metabolites will help design new approaches to engineer them. Here, we identified a PGT-specific R2R3-MYB gene, MsMYB, from comparative RNA-Seq data of spearmint and functionally characterized it. Analysis of MsMYB-RNAi transgenic lines showed increased levels of monoterpenes, and MsMYB-overexpressing lines exhibited decreased levels of monoterpenes. These results suggest that MsMYB is a novel negative regulator of monoterpene biosynthesis. Ectopic expression of MsMYB, in sweet basil and tobacco, perturbed sesquiterpene- and diterpene-derived metabolite production. In addition, we found that MsMYB binds to cis-elements of MsGPPS.LSU and suppresses its expression. Phylogenetic analysis placed MsMYB in subgroup 7 of R2R3-MYBs whose members govern phenylpropanoid pathway and are regulated by miR858. Analysis of transgenic lines showed that MsMYB is more specific to terpene biosynthesis as it did not affect metabolites derived from phenylpropanoid pathway. Further, our results indicate that MsMYB is probably not regulated by miR858, like other members of subgroup 7. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  1. Studies and Suggestions on Prewriting Activities

    ERIC Educational Resources Information Center

    Zheng, Shigao; Dai, Weiping

    2012-01-01

    This paper studies and suggests the need for writing instruction by which students can experience writing as a creative process in exploring and communicating meaning. The prewriting activities generate ideas which can encourage a free flow of thoughts and help students discover both what they want to say and how to say it on paper. Through the…

  2. Simultaneous determination of creatinine and creatine in human serum by double-spike isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS).

    PubMed

    Fernández-Fernández, Mario; Rodríguez-González, Pablo; Añón Álvarez, M Elena; Rodríguez, Felix; Menéndez, Francisco V Álvarez; García Alonso, J Ignacio

    2015-04-07

    This work describes the first multiple spiking isotope dilution procedure for organic compounds using (13)C labeling. A double-spiking isotope dilution method capable of correcting and quantifying the creatine-creatinine interconversion occurring during the analytical determination of both compounds in human serum is presented. The determination of serum creatinine may be affected by the interconversion between creatine and creatinine during sample preparation or by inefficient chemical separation of those compounds by solid phase extraction (SPE). The methodology is based on the use differently labeled (13)C analogues ((13)C1-creatinine and (13)C2-creatine), the measurement of the isotopic distribution of creatine and creatinine by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the application of multiple linear regression. Five different lyophilized serum-based controls and two certified human serum reference materials (ERM-DA252a and ERM-DA253a) were analyzed to evaluate the accuracy and precision of the proposed double-spike LC-MS/MS method. The methodology was applied to study the creatine-creatinine interconversion during LC-MS/MS and gas chromatography-mass spectrometry (GC-MS) analyses and the separation efficiency of the SPE step required in the traditional gas chromatography-isotope dilution mass spectrometry (GC-IDMS) reference methods employed for the determination of serum creatinine. The analysis of real serum samples by GC-MS showed that creatine-creatinine separation by SPE can be a nonquantitative step that may induce creatinine overestimations up to 28% in samples containing high amounts of creatine. Also, a detectable conversion of creatine into creatinine was observed during sample preparation for LC-MS/MS. The developed double-spike LC-MS/MS improves the current state of the art for the determination of creatinine in human serum by isotope dilution mass spectrometry (IDMS), because corrections are made for all the possible errors

  3. Analytical method for the accurate determination of tricothecenes in grains using LC-MS/MS: a comparison between MRM transition and MS3 quantitation.

    PubMed

    Lim, Chee Wei; Tai, Siew Hoon; Lee, Lin Min; Chan, Sheot Harn

    2012-07-01

    The current food crisis demands unambiguous determination of mycotoxin contamination in staple foods to achieve safer food for consumption. This paper describes the first accurate LC-MS/MS method developed to analyze tricothecenes in grains by applying multiple reaction monitoring (MRM) transition and MS(3) quantitation strategies in tandem. The tricothecenes are nivalenol, deoxynivalenol, deoxynivalenol-3-glucoside, fusarenon X, 3-acetyl-deoxynivalenol, 15-acetyldeoxynivalenol, diacetoxyscirpenol, and HT-2 and T-2 toxins. Acetic acid and ammonium acetate were used to convert the analytes into their respective acetate adducts and ammonium adducts under negative and positive MS polarity conditions, respectively. The mycotoxins were separated by reversed-phase LC in a 13.5-min run, ionized using electrospray ionization, and detected by tandem mass spectrometry. Analyte-specific mass-to-charge (m/z) ratios were used to perform quantitation under MRM transition and MS(3) (linear ion trap) modes. Three experiments were made for each quantitation mode and matrix in batches over 6 days for recovery studies. The matrix effect was investigated at concentration levels of 20, 40, 80, 120, 160, and 200 μg kg(-1) (n = 3) in 5 g corn flour and rice flour. Extraction with acetonitrile provided a good overall recovery range of 90-108% (n = 3) at three levels of spiking concentration of 40, 80, and 120 μg kg(-1). A quantitation limit of 2-6 μg kg(-1) was achieved by applying an MRM transition quantitation strategy. Under MS(3) mode, a quantitation limit of 4-10 μg kg(-1) was achieved. Relative standard deviations of 2-10% and 2-11% were reported for MRM transition and MS(3) quantitation, respectively. The successful utilization of MS(3) enabled accurate analyte fragmentation pattern matching and its quantitation, leading to the development of analytical methods in fields that demand both analyte specificity and fragmentation fingerprint-matching capabilities that are

  4. A pilot study to improve adherence among MS patients who discontinue treatment against medical advice.

    PubMed

    Bruce, Jared; Bruce, Amanda; Lynch, Sharon; Strober, Lauren; O'Bryan, Sean; Sobotka, Deborah; Thelen, Joan; Ness, Abigail; Glusman, Morgan; Goggin, Kathy; Bradley-Ewing, Andrea; Catley, Delwyn

    2016-04-01

    Between 30 and 50% of MS patients may prematurely discontinue disease modifying therapies. Little research has examined how to best talk with patients who have discontinued treatment against medical advice. The aim of this pilot study was to determine whether telephone counseling increases disease modifying therapy (DMT) re-initiation among nonadherent patients with multiple sclerosis (MS). Participants were eligible if they had relapsing-remitting disease, had stopped taking a DMT, and had no plan to re-initiate treatment despite a provider recommendation. Following a baseline assessment, 81 patients were randomly assigned to either five 20 min, weekly sessions of Motivational Interviewing/Cognitive Behavioral Therapy (MI-CBT) or Treatment as Usual (TAU) with brief education. At 10 weeks, patients initially assigned to TAU switched over to MI-CBT. Compared to patients in the TAU group, patients undergoing MI-CBT were significantly more likely to indicate they were re-initiating DMT (41.7 vs. 14.3%). These significant results were replicated among patients crossing over from TAU to MI-CBT. Treatment satisfaction was high, with 97% of participants reporting that they would recommend MI-CBT to other patients with MS. Results of this pilot study provide initial support for the use of MI-CBT among MS patients who have discontinued treatment against medical advice.Clinicaltrials.gov: NCT01925690.

  5. Independent highly sensitive characterization of asparagine deamidation and aspartic acid isomerization by sheathless CZE-ESI-MS/MS.

    PubMed

    Gahoual, Rabah; Beck, Alain; François, Yannis-Nicolas; Leize-Wagner, Emmanuelle

    2016-02-01

    Amino acids residues are commonly submitted to various physicochemical modifications occurring at physiological pH and temperature. Post-translational modifications (PTMs) require comprehensive characterization because of their major influence on protein structure and involvement in numerous in vivo process or signaling. Mass spectrometry (MS) has gradually become an analytical tool of choice to characterize PTMs; however, some modifications are still challenging because of sample faint modification levels or difficulty to separate an intact peptide from modified counterparts before their transfer to the ionization source. Here, we report the implementation of capillary zone electrophoresis coupled to electrospray ionization tandem mass spectrometry (CZE-ESI-MS/MS) by the intermediate of a sheathless interfacing for independent and highly sensitive characterization of asparagine deamidation (deaN) and aspartic acid isomerization (isoD). CZE selectivity regarding deaN and isoD was studied extensively using different sets of synthetic peptides based on actual tryptic peptides. Results demonstrated CZE ability to separate the unmodified peptide from modified homologous exhibiting deaN, isoD or both independently with a resolution systematically superior to 1.29. Developed CZE-ESI-MS/MS method was applied for the characterization of monoclonal antibodies and complex protein mixture. Conserved CZE selectivity could be demonstrated even for complex samples, and foremost results obtained showed that CZE selectivity is similar regardless of the composition of the peptide. Separation of modified peptides prior to the MS analysis allowed to characterize and estimate modification levels of the sample independently for deaN and isoD even for peptides affected by both modifications and, as a consequence, enables to distinguish the formation of l-aspartic acid or d-aspartic acid generated from deaN. Separation based on peptide modification allowed, as supported by the ESI

  6. Development and validation of a sensitive LC-MS/MS method with electrospray ionization for quantitation of pramipexole in human plasma: application to a clinical pharmacokinetic study.

    PubMed

    Bharathi, D Vijaya; Hotha, Kishore Kumar; Sagar, P V Vidya; Kumar, S Sirish; Naidu, A; Mullangi, Ramesh

    2009-02-01

    A highly sensitive and specific LC-MS/MS method has been developed and validated for the estimation of pramipexole (PPX) with 500 microL human plasma using memantine as an internal standard (IS). The API-4000 was operated under multiple-reaction monitoring mode (MRM) using the electrospray ionization technique. Solid-phase extraction was used to extract PPX and IS from human plasma. The resolution of peaks was achieved with 0.01 m ammonium acetate buffer (pH 4.4):acetonitrile (30:70, v/v) on a Discovery CN column. The total chromatographic run time was 3.0 min and the elution of PPX and IS occurred at approximately 2.32 and 2.52, respectively. The MS/MS ion transitions monitored were 212.10 --> 153.10 for PPX and 180.20 --> 107.30 for IS. The method was proved to be accurate and precise at linearity range of 20-3540 pg/mL with a correlation coefficient (r) of > or =0.999. The intra- and inter-day precision and accuracy values found to be within the assay variability limits as per the FDA guidelines. The developed assay method was applied to a pharmacokinetic study in human volunteers following oral administration of 0.25 mg PPX tablet. Copyright (c) 2008 John Wiley & Sons, Ltd.

  7. Chiral PCB 91 and 149 Toxicity Testing in Embryo and Larvae (Danio rerio): Application of Targeted Metabolomics via UPLC-MS/MS

    NASA Astrophysics Data System (ADS)

    Chai, Tingting; Cui, Feng; Yin, Zhiqiang; Yang, Yang; Qiu, Jing; Wang, Chengju

    2016-09-01

    In this study, we aimed to investigate the dysfunction of zebrafish embryos and larvae induced by rac-/(+)-/(-)- PCB91 and rac-/(-)-/(+)- PCB149. UPLC-MS/MS (Ultra-performance liquid chromatography coupled with mass spectrometry) was employed to perform targeted metabolomics analysis, including the quantification of 22 amino acids and the semi-quantitation of 22 other metabolites. Stereoselective changes in target metabolites were observed in embryos and larvae after exposure to chiral PCB91 and PCB149, respectively. In addition, statistical analyses, including PCA and PLS-DA, combined with targeted metabolomics were conducted to identify the characteristic metabolites and the affected pathways. Most of the unique metabolites in embryos and larvae after PCB91/149 exposure were amino acids, and the affected pathways for zebrafish in the developmental stage were metabolic pathways. The stereoselective effects of PCB91/149 on the metabolic pathways of zebrafish embryos and larvae suggest that chiral PCB91/149 exposure has stereoselective toxicity on the developmental stages of zebrafish.

  8. Ellagitannin composition of blackberry as determined by HPLC-ESI-MS and MALDI-TOF-MS.

    PubMed

    Hager, Tiffany J; Howard, Luke R; Liyanage, Rohana; Lay, Jackson O; Prior, Ronald L

    2008-02-13

    Blackberries ( Rubus sp.) were evaluated by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) to identify the ellagitannins present in flesh, torus (receptacle tissue), and seeds. Most ellagitannins were present (or detectable) only in seed tissues. Ellagitannins identified by HPLC-ESI-MS in the seeds included pedunculagin, casuarictin/potentillin, castalagin/vescalagin, lambertianin A/sanguiin H-6, lambertianin C, and lambertianin D. For several of the ellagitannins, isomeric separation was also obtained. The MALDI-TOF-MS analysis was primarily utilized to evaluate and identify high molecular mass (>1000 Da) ellagitannins. The MALDI analysis verified the presence of the ellagitannins identified by HPLC-ESI-MS including lambertianin A/sanguiin H-6, lambertianin C, and lambertianin D, but the analysis also indicated the presence of several other compounds that were most likely ellagitannins based on the patterns observed in the masses (i.e., loss or addition of a gallic acid moiety to a known ellagitannin). This study determined the presence of several possible isomeric forms of ellagitannins previously unidentified in fruit and presents a possible analytical HPLC method for the analysis of the major ellagitannins present in the fruit.

  9. Development and application of a UPLC-MS/MS method for the pharmacokinetic study of 10-hydroxy camptothecin and hydroxyethyl starch conjugate in rats.

    PubMed

    Li, Guofei; Cai, Cuifang; Ren, Tianyang; Tang, Xing

    2014-01-01

    With the purpose to carry out the pharmacokinetic studies of 10-hydroxy camptothecin (10-HCPT) and hydroxyethyl starch (10-HCPT-HES) conjugate, an ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated. The analytes, 10-HCPT and the internal standard, Diphenhydramine hydrochloride were extracted with ethyl acetate-isopropanol (95:5, v/v) and separated on an ACQUITY UPLC™ BEH C18 column using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) with a linear gradient program. With positive ion electrospray ionization (ESI), the analytes were monitored on a triple quadrupole mass spectrometer in the multiple reaction monitoring (MRM) mode. Linear calibration curves were obtained over the concentration ranges of 0.5-2500ng/mL. The intra- and inter-day precisions were less than 9.8% and 10.8%, respectively. The accuracy was within 12.1%. The mean recoveries of 10-HCPT at three concentrations of 2.5, 100, 2000ng/mL were higher than 87.2%. Commercial 10-HCPT injection and 10-HCPT-HES conjugate were administered intravenously at an equal dose of 10-HCPT at 0.5mg/kg. The biological half-life of conjugate was increased significantly from 10min to 3.15h and the bioavailability was 40 times higher than 10-HCPT injection. Consequently, the proposed UPLC-ESI-MS/MS method was proved to be sensitive, specific and reliable to analyze 10-HCPT in biological samples; 10-HCPT and HES conjugate is a promising strategy for delivery of 10-HCPT with prolonged half time and improved bioavailability. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Circulating dendritic cells of multiple sclerosis patients are proinflammatory and their frequency is correlated with MS-associated genetic risk factors.

    PubMed

    Thewissen, Kristof; Nuyts, Amber H; Deckx, Nathalie; Van Wijmeersch, Bart; Nagels, Guy; D'hooghe, Marie; Willekens, Barbara; Cras, Patrick; Eijnde, Bert O; Goossens, Herman; Van Tendeloo, Viggo F I; Stinissen, Piet; Berneman, Zwi N; Hellings, Niels; Cools, Nathalie

    2014-04-01

    The role of the adaptive immune system and more specifically T cells in the pathogenesis of multiple sclerosis (MS) has been studied extensively. Emerging evidence suggests that dendritic cells (DCs), which are innate immune cells, also contribute to MS. This study aimed to characterize circulating DC populations in MS and to investigate the contribution of MS-associated genetic risk factors to DCs. Ex vivo analysis of conventional (cDCs) and plasmacytoid DCs (pDCs) was carried out on peripheral blood of MS patients (n = 110) and age- and gender-matched healthy controls (n = 112). Circulating pDCs were significantly decreased in patients with chronic progressive MS compared to relapsing-remitting MS and healthy controls. While no differences in cDCs frequency were found between the different study groups, HLA-DRB1*1501(+) MS patients and patients not carrying the protective IL-7Rα haplotype 2 have reduced frequencies of circulating cDCs and pDCs, respectively. MS-derived DCs showed enhanced IL-12p70 production upon TLR ligation and had an increased expression of the migratory molecules CCR5 and CCR7 as well as an enhanced in vitro chemotaxis. DCs in MS are in a pro-inflammatory state, have a migratory phenotype and are affected by genetic risk factors, thereby contributing to pathogenic responses.

  11. [Determination of plasma concentration of five phenolic acid by LC-MS/MS and study of pharmacokinetics in rats after Mailuoning injection].

    PubMed

    Wu, Ting; Zhang, Jun; Tan, Heng-Shan; Ju, Wen-Zheng; Xu, Xiang-Yang

    2014-05-01

    To establish a LC-MS/MS method for quantification of chlorogenic acid, caffeic acid, 3,4-DCQA, ferulic acid and cinnamic acid in rats plasma and study its pharmacokinetics after administration of Mailuoning injection at a single dose to rats. Plasma samples were acidified with hydrochloric acid and extracted with ethyl acetate. The analytes were determined by LC-MS-MS using a ZOBAX SB C18 column with a mobile phase of methanol-water (containing 2 mmol x L(-1) ammonium acetic) (60:40)at a flow rate of 0.5 mL x min(-1) and detected using ESI with negative ionization mode. Ions monitored in the multiple reaction monitoring (MRM) mode were m/z 353.1/191.0 [M-H]- for chlorogenic acid, m/z 178.9/134.9 [M-H]- for caffeic acid, m/z 515.2/353.0 [M-H]-for 3,4-DCQA, m/z 193.0/133.9 [M-H]-for ferulic acid, m/z 146.9/102.9 [M-H]- for cinnamic acid and m/z 246.0/125.8 [M-H]- for tinidazole (IS). After administration of Mailuoning injection at a single dose to eight Sprague-Dawley rats, the concentrations of chlorogenic acid, caffeic acid, 3,4-DCQA, ferulic acid and cinnamic acid in plasma were determined by LC-MS/MS method. The main pharmacokinetics parameters of measured data were caluculated by using DASver 1.0 software. The linear concentration ranges of the calibration curves for chlorogenic acid, caffeic acid, 3,4-DCQA and cinnamic acid were 2.006-1,027 microg x L(-1) (r = 0.999 6), 1.953-1,000 microg x L(-1) (r = 0.999 7), 28.51-1.459 x 10(4) microg x L(-1) (r = 0.998 9), 1.836-940.0, g x L(-1) (r = 0.997 7) and 4.780-2,447 microg x L(-1) (r = 0.998 6) respectively. The inner and inter-days relative standard deviations were both less than 5.0%, indicating legitimate precise and accuracy to the requirement of biological sample analysis. For chlorogenic acid, the pharmacokinetic parameter t1/2, AUC0-t, and CL were (49.78 +/- 12.81) min, (123.55 +/- 14.82) mg x min x L(-1) and (0.004 3 +/- 0.000 5) L x min(-1), respectively. For caffeic acid, the pharmacokinetic parameter t1

  12. Endocrine system dynamics and MS epidemiology.

    PubMed

    Moynihan, James; Moore, Helena

    2010-05-01

    In the kidney there is a co-transport relationship in the nephron between the reabsorption of positive Na(+) ions and the reabsorption of negative ions such as uric acid anions. Uric acid acts as an anti-oxidant and it has been shown to have a sealing effect on the blood-brain barrier. The theory developed here is that chronic neurological vasoconstriction in cool environmental conditions injects an offset into the rennin-angiotensin-aldosterone system (RAAS) blood pressure control loop and reduces demand for angiotensin and aldosterone. (Aldosterone is produced in the adrenal gland and has a direct effect on renal reabsorption of Na(+) ions.) Via co-transport these conditions will reduce the body's ability to reabsorb uric acid and this in turn will weaken the integrity of the blood-brain barrier. Also, in cool environments, where levels of vasopressin (ADH) and aldosterone are lower, the gain of the hypothalamus-pituitary-adrenal gland (HPA) axis is reduced so that the production average levels of ACTH, cortisone and aldosterone will be biased at a lower level and the kidney-local levels of aldosterone in particular will remain lower. This paper develops these ideas and suggests that they can help explain the traditionally-recognized latitudinal gradient in MS epidemiology. Also, acclimatization to heat encourages sweating, which should create a greater demand for the renal reabsorption of Na(+) ions which enables greater reabsorption of uric acid. Therefore people living at low latitudes should have a lower chance of hypouricemia and a lower chance of developing MS. In fact people who spend their first fifteen years in the tropics almost never go onto develop MS. And MS patients in relapse are consistently hypouricemic. This hypothesis can explain both of these facts. The paper goes onto show how the MS condition will tend to progress because of a number of self-sustaining effects: over time the immune system becomes more targeted to myelin, MS patients are

  13. Determination of parthenolide in rat plasma by UPLC-MS/MS and its application to a pharmacokinetic study.

    PubMed

    Zhao, Ai-qin; Zhao, Ji-hong; Zhang, Shu-qing; Pan, Yong-yang; Huo, Xu-lei

    2016-02-05

    A rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the determination and pharmacokinetic investigation of parthenolide in rat plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2mL of acetonitrile containing 30ng/mL of pirfenidone (IS), and to a 0.1mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 3.0min and the elution of parthenolide was at 1.33min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 249.2→231.1 for parthenolide and m/z 186.2→92.1 for pirfenidone (IS), respectively. The calibration curve was linear over the range of 2.0-500ng/mL with a lower limit of quantitation (LLOQ) of 2.0ng/mL. Mean recovery of parthenolide in plasma was in the range of 78.2-86.6%. Intra-day and inter-day precision were both <8.3%. This method was successfully applied in pharmacokinetic study after oral and intravenous administration of parthenolide in rats. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Immunoassay or LC-MS/MS for the measurement of salivary cortisol in children?

    PubMed

    Bae, Yoon Ju; Gaudl, Alexander; Jaeger, Sonia; Stadelmann, Stephanie; Hiemisch, Andreas; Kiess, Wieland; Willenberg, Anja; Schaab, Michael; von Klitzing, Kai; Thiery, Joachim; Ceglarek, Uta; Döhnert, Mirko; Kratzsch, Juergen

    2016-05-01

    Dysregulation of the adrenal cortex has been assessed with measurement of salivary cortisol. So far salivary cortisol is routinely measured with immunoassay (IA). However, liquid chromatography-tandem mass spectrometry (MS) is known to offer better specificity. We compared the concentrations of salivary cortisol measured by MS and IA at basal and stress induced conditions and evaluated reasons for the difference in method-dependent cortisol results. Saliva samples (n=2703) were collected from 169 children (age range: 8-14 years; 81 healthy children; 55 with internalizing and 33 with externalizing disorders) under circadian conditions and during the Trier Social Stress Test for Children (TSST-C). Biochemical analyses were performed with MS for cortisol and cortisone, IA (IBL, RE62011) for cortisol, and enzyme kinetic assay for α-amylase. MS and IA showed mostly comparable results for circadian activity and TSST-C response with similar statistical power. However, IA measured cortisol concentrations about 2.39-fold higher than MS. We found that this difference in measured values between MS and IA was mainly due to different standardization of IA compared to MS. In addition, at cortisol IA concentration below 5 nmol/L, cross-reactivity with cortisone was found to contribute to the lower concordance between MS and IA. Immunoassay and LC-MS/MS were largely comparable in the interpretation of salivary cortisol dynamics in stress research. But the IA method revealed a restricted accuracy in the measuring range below 5 nmol/L.

  15. UPLC/MS-MS assay development for estimation of mozavaptan in plasma and its pharmacokinetic study in rats.

    PubMed

    Ezzeldin, Essam; Mostafa, Gamal Ae; Iqbal, Muzaffar; Al-Rashood, Khalid A; Asiri, Yousef; El-Nahhas, Toqa

    2018-05-10

    Mozavaptan is a nonpeptide vasopressin receptor antagonist approved for the treatment of ectopic antidiuretic hormone secretion syndrome. A simple, rapid and fully validated UPLC/MS-MS method was developed for the quantitation of mozavaptan in rat plasma. The chromatographic separation was conducted on an Acquity UPLC BEH™ C 18 column with an optimum mobile phase of 10 mM ammonium acetate buffer and 0.1% formic acid in acetonitrile (30:70 v/v) at a flow rate of 0.3 ml/min. The multiple reaction monitoring transitions were performed at m/z 428.16→119.03 for mozavaptan and m/z 237.06→179.10 for carbamazepine (internal standard). The method was effectively applied for the determination of mozavaptan pharmacokinetic parameters after the oral administration of 3 mg/kg mozavaptan in rats.

  16. Factors associated with recently transmitted Mycobacterium tuberculosis strain MS0006 in Hinds County, Mississippi.

    PubMed

    Temple, Brian; Kwara, Awewura; Sunesara, Imran; Mena, Leandro; Dobbs, Thomas; Henderson, Harold; Holcomb, Mike; Webb, Risa

    2011-12-01

    The objective of this study was to investigate risk factors associated with tuberculosis (TB) transmission that was caused by Mycobacterium tuberculosis strain MS0006 from 2004 to 2009 in Hinds County, Mississippi. DNA fingerprinting using spoligotyping, mycobacterial interspersed repetitive unit, and IS6110-based restriction fragment length polymorphism of culture-confirmed cases of TB was performed. Clinical and demographic factors associated with strain MS0006 were analyzed by univariate and multivariate analysis. Of the 144 cases of TB diagnosed during the study period, 117 were culture positive with fingerprints available. There were 48 different strains, of which 6 clustered strains were distributed among 74 patients. The MS0006 strain accounted for 46.2% of all culture-confirmed cases. Risk factors for having the MS0006 strain in a univariate analysis included homelessness, HIV co-infection, sputum smear negativity, tuberculin skin test negativity, and noninjectable drug use. Multivariate analysis identified homelessness (odds ratio 7.88, 95% confidence interval 2.90-21.35) and African American race (odds ratio 5.80, 95% confidence interval 1.37-24.55) as independent predictors of having TB caused by the MS0006 strain of M. tuberculosis. Our findings suggest that a majority of recently transmitted TB in the studied county was caused by the MS0006 strain. African American race and homelessness were significant risk factors for inclusion in the cluster. Molecular epidemiology techniques continue to provide in-depth analysis of disease transmission and play a vital role in effective contact tracing and interruption of ongoing transmission.

  17. Development of a LC-MS/MS method for simultaneous determination of metoprolol and its metabolites, α-hydroxymetoprolol and O-desmethylmetoprolol, in rat plasma: application to the herb-drug interaction study of metoprolol and breviscapine.

    PubMed

    Rao, Zhi; Ma, Yan-rong; Qin, Hong-yan; Wang, Ya-feng; Wei, Yu-hui; Zhou, Yan; Zhang, Guo-qiang; Wang, Xing-dong; Wu, Xin-an

    2015-09-01

    A simple, specific and sensitive LC-MS/MS method was developed and validated for the simultaneous determination of metoprolol (MET), α-hydroxymetoprolol (HMT) and O-desmethylmetoprolol (DMT) in rat plasma. The plasma samples were prepared by protein precipitation, then the separation of the analytes was performed on an Agilent HC-C18 column (4.6 × 250 mm, 5 µm) at a flow rate of 1.0 mL/min, and post-column splitting (1:4) was used to give optimal interface flow rates (0.2 mL/min) for MS detection; the total run time was 8.5 min. Mass spectrometric detection was achieved using a triple-quadrupole mass spectrometer equipped with an electrospray source interface in positive ionization mode. The method was fully validated in terms of selectivity, linearity, accuracy, precision, stability, matrix effect and recovery over a concentration range of 3.42-7000 ng/mL for MET, 2.05-4200 ng/mL for HMT and 1.95-4000 ng/mL for DMT. The analytical method was successfully applied to herb-drug interaction study of MET and breviscapine after administration of breviscapine (12.5 mg/kg) and MET (40 mg/kg). The results suggested that breviscapine have negligible effect on pharmacokinetics of MET in rats; the information may be beneficial for the application of breviscapine in combination with MET in clinical therapy. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Infections in MS: An innate immunity perspective.

    PubMed

    Hänninen, A

    2017-11-01

    Multiple sclerosis is a multifaceted inflammatory-autoimmune disease, which shows remarkable heterogeneity in its clinical presentation, disease progression and in tissue lesions in the CNS. Focal lesions in white matter consist of immune effector cells, antibodies, and complement deposits in varying combinations, suggesting that immune mechanisms related to CNS pathology are multiple. Although adaptive immunity to myelin antigens is essential in MS pathogenesis, innate immune mechanisms are likely involved in its initiation and perpetuation. One key question is if recognition of infectious agents and microbial products by innate immune mechanisms impacts on MS and if so, how and where? This short review aims at conceptualizing how interactions between microbes and innate immune mechanisms could contribute to MS pathogenesis. Consideration is given to initiation of local inflammation and to myelin-specific immune responses, and how innate immunity and microbes may contribute to these. Recent advances in our understanding of lymphatic drainage of CNS, its immune surveillance and effects of gut microbiota and obesity on systemic endotoxin levels and T-cell priming may open new perspectives to understanding the roles that infectious agents and microbes may have in MS. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. The role of suggestibility in determinations of Miranda abilities: a study of the Gudjonsson Suggestibility Scales.

    PubMed

    Rogers, Richard; Harrison, Kimberly S; Rogstad, Jill E; LaFortune, Kathryn A; Hazelwood, Lisa L

    2010-02-01

    Traditionally, high levels of suggestibility have been widely assumed to be linked with diminished Miranda abilities, especially in relationship to the voluntariness of waivers. The current investigation examined suggestibility on the Gudjonsson Suggestibility Scales in a multisite study of pretrial defendants. One important finding was the inapplicability of British norms to American jurisdictions. Moreover, suggestibility appeared unrelated to Miranda comprehension, reasoning, and detainees' perceptions of police coercion. In testing rival hypotheses, defendants with high compliance had significantly lower Miranda comprehension and ability to reason about exercising Miranda rights than their counterparts with low compliance. Implications of these findings to forensic practice are examined.

  20. Analysis of multiple vitamin D metabolites by ultra-performance supercritical fluid chromatography-tandem mass spectrometry (UPSFC-MS/MS).

    PubMed

    Jenkinson, Carl; Taylor, Angela; Storbeck, Karl-Heinz; Hewison, Martin

    2018-06-15

    In recent years, increased interest in the human health benefits of vitamin D has led to demand for improved analysis of patient vitamin D 'status'. Studies to date have focused primarily on a single vitamin D metabolite, 25-hydroxyvitamin D, despite the existence of a broad range of vitamin D metabolites, referred to as the vitamin D metabolome. This study reports on the development of a rapid UPSFC-MS/MS method for the analysis of nine vitamin D metabolites in human serum. Optimum separation was obtained with a Lux-Cellulose chiral column. We observed an orthogonal elution order when compared with ultra-high performance liquid chromatography (UHPLC). The order of elution was reversed based on hydroxyl- group number, however elution order did not differ between isomeric changes in hydroxyl- group position or epimers. Although UPSFC yielded superior resolution and selectivity over previously developed UHPLC-MS/MS methods, improvements in sensitivity could not be achieved owing to the lower injection volume required for UPSFC relative to UHPLC. Method validation was performed on the developed UPSFC-MS/MS method and found to be within acceptable limits. Applying the method to the analysis of human serum samples showed a significant correlation with serum concentrations of metabolites measured by UHPLC-MS/MS (25OHD3 r = 0.997, P=<0.001, and 3-epi-25OHD3 r = 0.996, P ≤0.001). These data indicate that UPSFC provides an efficient analytical platform for rapid analysis of multiple vitamin D metabolites from serum. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  1. Exploring the in vitro formation of trimethylarsine sulfide from dimethylthioarsinic acid in anaerobic microflora of mouse cecum using HPLC-ICP-MS and HPLC-ESI-MS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kubachka, Kevin M.; Kohan, Michael C.; Herbin-Davis, Karen

    Although metabolism of arsenicals to form methylated oxoarsenical species has been extensively studied, less is known about the formation of thiolated arsenical species that have recently been detected as urinary metabolites. Indeed, their presence suggests that the metabolism of ingested arsenic is more complex than previously thought. Recent reports have shown that thiolated arsenicals can be produced by the anaerobic microflora of the mouse cecum, suggesting that metabolism prior to systemic absorption may be a significant determinant of the pattern and extent of exposure to various arsenic-containing species. Here, we examined the metabolism of {sup 34}S labeled dimethylthioarsinic acid ({supmore » 34}S-DMTA{sup V}) by the anaerobic microflora of the mouse cecum using HPLC-ICP-MS and HPLC-ESI-MS/MS to monitor for the presence of various oxo- and thioarsenicals. The use of isotopically enriched {sup 34}S-DMTA{sup V} made it possible to differentiate among potential metabolic pathways for production of the trimethylarsine sulfide (TMAS{sup V}). Upon in vitro incubation in an assay containing anaerobic microflora of mouse cecum, {sup 34}S-DMTA{sup V} underwent several transformations. Labile {sup 34}S was exchanged with more abundant {sup 32}S to produce {sup 32}S-DMTA{sup V}, a thiol group was added to yield DMDTA{sup V}, and a methyl group was added to yield {sup 34}S-TMAS{sup V}. Because incubation of {sup 34}S-DMTA{sup V} resulted in the formation of {sup 34}S-TMAS{sup V}, the pathway for its formation must preserve the arsenic-sulfur bond. The alternative metabolic pathway postulated for formation of TMAS{sup V} from dimethylarsinic acid (DMA{sup V}) would proceed via a dimethylarsinous acid (DMA{sup III}) intermediate and would necessitate the loss of {sup 34}S label. Structural confirmation of the metabolic product was achieved using HPLC-ESI-MS/MS. The data presented support the direct methylation of DMTA{sup V} to TMAS{sup V}. Additionally, the

  2. Segmental analysis of amphetamines in hair using a sensitive UHPLC-MS/MS method.

    PubMed

    Jakobsson, Gerd; Kronstrand, Robert

    2014-06-01

    A sensitive and robust ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxy methamphetamine in hair samples. Segmented hair (10 mg) was incubated in 2M sodium hydroxide (80°C, 10 min) before liquid-liquid extraction with isooctane followed by centrifugation and evaporation of the organic phase to dryness. The residue was reconstituted in methanol:formate buffer pH 3 (20:80). The total run time was 4 min and after optimization of UHPLC-MS/MS-parameters validation included selectivity, matrix effects, recovery, process efficiency, calibration model and range, lower limit of quantification, precision and bias. The calibration curve ranged from 0.02 to 12.5 ng/mg, and the recovery was between 62 and 83%. During validation the bias was less than ±7% and the imprecision was less than 5% for all analytes. In routine analysis, fortified control samples demonstrated an imprecision <13% and control samples made from authentic hair demonstrated an imprecision <26%. The method was applied to samples from a controlled study of amphetamine intake as well as forensic hair samples previously analyzed with an ultra high performance liquid chromatography time of flight mass spectrometry (UHPLC-TOF-MS) screening method. The proposed method was suitable for quantification of these drugs in forensic cases including violent crimes, autopsy cases, drug testing and re-granting of driving licences. This study also demonstrated that if hair samples are divided into several short segments, the time point for intake of a small dose of amphetamine can be estimated, which might be useful when drug facilitated crimes are investigated. Copyright © 2014 John Wiley & Sons, Ltd.

  3. MS in Your Relationships

    MedlinePlus

    ... Disease T Cells d What Causes MS? Disproved Theories Viruses Clusters d Who Gets MS? Pediatric MS ... of Distinction Lawry Circle Circle of Influence d Planned Giving d Other Ways to Give Donate by ...

  4. Primary-Progressive MS (PPMS)

    MedlinePlus

    ... Disease T Cells d What Causes MS? Disproved Theories Viruses Clusters d Who Gets MS? Pediatric MS ... of Distinction Lawry Circle Circle of Influence d Planned Giving d Other Ways to Give Donate by ...

  5. Progressive-Relapsing MS (PRMS)

    MedlinePlus

    ... Disease T Cells d What Causes MS? Disproved Theories Viruses Clusters d Who Gets MS? Pediatric MS ... of Distinction Lawry Circle Circle of Influence d Planned Giving d Other Ways to Give Donate by ...

  6. Secondary-Progressive MS (SPMS)

    MedlinePlus

    ... Disease T Cells d What Causes MS? Disproved Theories Viruses Clusters d Who Gets MS? Pediatric MS ... of Distinction Lawry Circle Circle of Influence d Planned Giving d Other Ways to Give Donate by ...

  7. A pre-clinical pharmacokinetic study in rats of three naturally occurring iridoid glycosides, Picroside-I, II and III, using a validated simultaneous HPLC-MS/MS assay.

    PubMed

    Zhu, Jianwei; Xue, Bingyang; Ma, Bo; Zhang, Qi; Liu, Ming; Liu, Lei; Yao, Di; Qi, Huanhuan; Wang, Yonglu; Ying, Hanjie; Wu, Zimei

    2015-07-01

    A selective and sensitive high-performance liquid chromatography-electro-spray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the simultaneous quantitative determination of Picroside-I, II, and III in rat plasma and tissue homogenate to aid the pre-clinical studies. The chromatographic separation was performed on a Hypersil GOLD AQ C18 column using a gradient elution program with a mobile phase consisting of 2mM ammonium acetate and acetonitrile. The detection was achieved using a triple quadrupole tandem MS in negative ionization multiple reaction monitoring (MRM) mode. One-step protein precipitation was selected for plasma and tissue sample preparation while liquid-liquid extraction failed to achieve satisfactory recoveries. The calibration curves of all three analytes in either plasma or tissue homogenate showed good linearity over the concentration range of 0.5-500ng/mL with a limit of quantitation at 0.5ng/mL. Both the intra- and inter-day accuracy and precision were within ±10%. The extraction recoveries were >70%, and the relative matrix effect ranged from 80.4% to 107.4% in all the biological samples. All the analytes were stable in matrices for at least 24h at room temperature, or 21 days in frozen. Three freeze/thaw cycles did not cause degradation. The method was successfully applied for quantification of the three iridoid glycosides in the collected plasma and various tissues following intravenous administration in rats. Picroside-I, II, and III were all eliminated rapidly with large volume of distribution. Among the three glycosides, Picroside-II showed the highest liver uptake, and only Picroside-I and II were found to get across the blood brain barrier (BBB). These results were consistent with their hepatoprotective or neuroprotective effects reported clinically. With the aid of the efficient and reliable simultaneous LC-ESI-MS/MS assay this pharmacokinetic study provided insights into their therapeutic targets of these

  8. Lidocaine Hydrochloride Compared with MS222 for the Euthanasia of Zebrafish (Danio rerio).

    PubMed

    Collymore, Chereen; Banks, E Kate; Turner, Patricia V

    2016-11-01

    Despite several shortcomings, MS222 is the most commonly used chemical agent for euthanasia of zebrafish. Although lidocaine hydrochloride has some advantages over MS222, its effectiveness as a euthanasia agent for zebrafish is unknown. Larvae at 9 to 16 d postfertilization were exposed to 250 mg/L MS222 or 400, 500, 600, 700, 800, 900, or 1000 mg/L lidocaine and observed for cessation of heartbeat. Adult zebrafish were exposed to 250 mg/L MS222 or 400, 500, or 600 mg/L lidocaine; times to loss of righting reflex, cessation of opercular movement, and complete recovery; body length; aversive behavior; and gross and microscopic evidence of acute toxicity were evaluated. The heartbeat was not lost from any larvae in any group, regardless of drug or dosage. For adults, time to loss of righting reflex was greatest in the 500-mg/L lidocaine group. Opercular movement ceased earlier in all lidocaine groups compared with the MS222 group. Fish in the 500-mg/L lidocaine group were smaller than those in other groups. Fewer fish in the lidocaine groups displayed aversive behavior (erratic swimming and piping) compared with the MS222 group. No fish in the lidocaine hydrochloride groups (n = 30) recovered from euthanasia, whereas one fish in the MS222 group did (n = 10). Neither the MS222 nor lidocaine groups showed any gross or histologic changes suggestive of acute toxicity. Our results suggest that lidocaine hydrochloride may be an effective alternative chemical euthanasia agent for adult zebrafish but should not be used in larval fish.

  9. Lidocaine Hydrochloride Compared with MS222 for the Euthanasia of Zebrafish (Danio rerio)

    PubMed Central

    Collymore, Chereen; Banks, E Kate; Turner, Patricia V

    2016-01-01

    Despite several shortcomings, MS222 is the most commonly used chemical agent for euthanasia of zebrafish. Although lidocaine hydrochloride has some advantages over MS222, its effectiveness as a euthanasia agent for zebrafish is unknown. Larvae at 9 to 16 d postfertilization were exposed to 250 mg/L MS222 or 400, 500, 600, 700, 800, 900, or 1000 mg/L lidocaine and observed for cessation of heartbeat. Adult zebrafish were exposed to 250 mg/L MS222 or 400, 500, or 600 mg/L lidocaine; times to loss of righting reflex, cessation of opercular movement, and complete recovery; body length; aversive behavior; and gross and microscopic evidence of acute toxicity were evaluated. The heartbeat was not lost from any larvae in any group, regardless of drug or dosage. For adults, time to loss of righting reflex was greatest in the 500-mg/L lidocaine group. Opercular movement ceased earlier in all lidocaine groups compared with the MS222 group. Fish in the 500-mg/L lidocaine group were smaller than those in other groups. Fewer fish in the lidocaine groups displayed aversive behavior (erratic swimming and piping) compared with the MS222 group. No fish in the lidocaine hydrochloride groups (n = 30) recovered from euthanasia, whereas one fish in the MS222 group did (n = 10). Neither the MS222 nor lidocaine groups showed any gross or histologic changes suggestive of acute toxicity. Our results suggest that lidocaine hydrochloride may be an effective alternative chemical euthanasia agent for adult zebrafish but should not be used in larval fish. PMID:27931323

  10. Effects of cannabis on cognition in patients with MS: a psychometric and MRI study.

    PubMed

    Pavisian, Bennis; MacIntosh, Bradley J; Szilagyi, Greg; Staines, Richard W; O'Connor, Paul; Feinstein, Anthony

    2014-05-27

    To determine functional and structural neuroimaging correlates of cognitive dysfunction associated with cannabis use in multiple sclerosis (MS). In a cross-sectional study, 20 subjects with MS who smoked cannabis and 19 noncannabis users with MS, matched on demographic and neurologic variables, underwent fMRI while completing a test of working memory, the N-Back. Resting-state fMRI and structural MRI data (lesion and normal-appearing brain tissue volumes, diffusion tensor imaging metrics) were also collected. Neuropsychological data pertaining to verbal (Selective Reminding Test Revised) and visual (10/36 Spatial Recall Test) memory, information processing speed (Paced Auditory Serial Addition Test [2- and 3-second versions] and Symbol Digit Modalities Test), and attention (Word List Generation) were obtained. The cannabis group performed more poorly on the more demanding of the Paced Auditory Serial Addition Test tasks (i.e., 2-second version) (p < 0.02) and the 10/36 Spatial Recall Test (p < 0.03). Cannabis users had more diffuse cerebral activation across all N-Back trials and made more errors on the 2-Back task (p < 0.006), during which they displayed increased activation relative to nonusers in parietal (p < 0.007) and anterior cingulate (p < 0.001) regions implicated in working memory. No group differences in resting-state networks or structural MRI variables were found. Patients with MS who smoke cannabis are more cognitively impaired than nonusers. Cannabis further compromises cerebral compensatory mechanisms, already faulty in MS. These imaging data boost the construct validity of the neuropsychological findings and act as a cautionary note to cannabis users and prescribers. © 2014 American Academy of Neurology.

  11. On-road assessment of fitness-to-drive in persons with MS with cognitive impairment: A prospective study.

    PubMed

    Morrow, Sarah A; Classen, Sherrilene; Monahan, Miriam; Danter, Tim; Taylor, Robert; Krasniuk, Sarah; Rosehart, Heather; He, Wenqing

    2017-08-01

    Cognitive impairment is common in multiple sclerosis (MS). In other populations, cognitive impairment is known to affect fitness-to-drive. Few studies have focused on fitness-to-drive in MS and no studies have solely focused on the influence of cognitive impairment. To assess fitness-to-drive in persons with MS with cognitive impairment and low physical disability. Persons with MS, aged 18-59 years with EDSS ⩽ 4.0, impaired processing speed, and impairment on at least one measure of memory or executive function, were recruited. Cognition was assessed using the Minimal Assessment of Cognitive Function battery. A formal on-road driving assessment was conducted. Chi-square analysis examined the association between the fitness-to-drive (pass/fail) and the neuropsychological test results (normal/impaired). Bayesian statistics predicting failure of the on-road assessment were calculated. Of 36 subjects, eight (22.2%) were unfit to drive. Only the BVMTR-IR, measuring visual-spatial memory, predicted on-road driving assessment failure ( X 2 ( df = 1, N = 36) = 3.956; p = 0.047) with a sensitivity of 100%, but low specificity (35.7%) due to false positives (18/25). In persons with MS and impaired processing speed, impairment on the BVMTR-IR should lead clinicians to address fitness-to-drive.

  12. Capillary electrophoresis interfaced with a mass spectrometer (CE-MS): technical considerations and applicability for biomarker studies in animals.

    PubMed

    Albalat, Amaya; Husi, Holger; Siwy, Justyna; Nally, Jarlath E; McLauglin, Mark; Eckersall, Peter D; Mullen, William

    2014-02-01

    Proteomics is a growing field that has the potential to be applied to many biology-related disciplines. However, the study of the proteome has proven to be very challenging due to its high level of complexity when compared to genome and transcriptome data. In order to analyse this level of complexity, high resolution separation of peptides/proteins are needed together with high resolution analysers. Currently, liquid chromatography and capillary electrophoresis (CE) are the two most widely used separation techniques that can be coupled on-line with a mass spectrometer (MS). In CE, proteins/ peptides are separated according to their size, charge and shape leading to high resolving power. Although further progress in the area of sensitivity, throughput and proteome coverage are expected, MS-based proteomics have developed to a level at which they are habitually applied to study a wide range of biological questions. The aim of this review is to present CE-MS as a proteomic analytical platform for biomarker research that could be used in farm animal and veterinary studies. This is a MS-analytical platform that has been widely used for biomarker research in the biomedical field but its application in animal proteomic studies is relatively novel. The review will focus on introducing the CE-MS platform and the primary considerations for its application to biomarker research. Furthermore, current applications but more importantly potential application in the field of farm animals and veterinary science will be presented and discussed.

  13. Measurement of trace levels of antibiotics in river water using on-line enrichment and triple-quadrupole LC-MS/MS.

    PubMed

    Dinh, Quoc Tuc; Alliot, Fabrice; Moreau-Guigon, Elodie; Eurin, Joëlle; Chevreuil, Marc; Labadie, Pierre

    2011-09-15

    This study presents the development of an automated on-line solid phase extraction (SPE)-liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of 23 antibiotics in environmental water samples. After optimisation of LC-MS/MS conditions, SPE parameters such as sorbent type, sample pH or sample volume were optimised. Antibiotic recoveries ranged from 64% to 98% and compared favourably with those achieved using off-line SPE. Limits of detection were in the range 0.5-13.7 ng L(-1). This on-line SPE-LC-MS/MS procedure was applied to the analysis of water samples taken in three rivers within the Seine River basin, near Paris (France). The obtained results revealed the occurrence of 12 antibiotics, including tylosin, erythromycin, tetracycline, amoxicillin, trimethoprim, sulfamethoxazole, oxolinic acid, flumequine, norfloxacin, ciprofloxacin, ofloxacin, and vancomycin (2-1435 ng L(-1)). Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Determination of nicotianamine in soy sauce and other plant-based foods by LC-MS/MS.

    PubMed

    Yamaguchi, Hitomi; Uchida, Riichiro

    2012-10-10

    Nicotianamine is a nonproteinogenic amino acid, known to be an important metal chelator in plants. Recently, the antihypertensive effect of nicotianamine was discovered. In this study, a simple method to determine nicotianamine was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with a multimode ODS column. This method does not need derivatizing or ion-pairing reagents to retain nicotianamine, which is known for its poor retention on reversed-phase columns because of its high polarity. Moreover, this method showed a sufficient limit of detection (0.5 ng/mL), so it was found to be suitable for the analysis of nicotianamine in soy sauce and other foods, without cleanup. To subtract the matrix effect during LC-MS/MS analysis, a standard addition method was used. The levels of nicotianamine in soy sauce ranged from <0.25 to 71 μg/g. Nicotianamine was also determined in other foods, including soy milk, vegetable juice, fruit juice, and bottled tea.

  15. Suggestion-Induced Modulation of Semantic Priming during Functional Magnetic Resonance Imaging

    PubMed Central

    Ulrich, Martin; Kiefer, Markus; Bongartz, Walter; Grön, Georg; Hoenig, Klaus

    2015-01-01

    Using functional magnetic resonance imaging during a primed visual lexical decision task, we investigated the neural and functional mechanisms underlying modulations of semantic word processing through hypnotic suggestions aimed at altering lexical processing of primes. The priming task was to discriminate between target words and pseudowords presented 200 ms after the prime word which was semantically related or unrelated to the target. In a counterbalanced study design, each participant performed the task once at normal wakefulness and once after the administration of hypnotic suggestions to perceive the prime as a meaningless symbol of a foreign language. Neural correlates of priming were defined as significantly lower activations upon semantically related compared to unrelated trials. We found significant suggestive treatment-induced reductions in neural priming, albeit irrespective of the degree of suggestibility. Neural priming was attenuated upon suggestive treatment compared with normal wakefulness in brain regions supporting automatic (fusiform gyrus) and controlled semantic processing (superior and middle temporal gyri, pre- and postcentral gyri, and supplementary motor area). Hence, suggestions reduced semantic word processing by conjointly dampening both automatic and strategic semantic processes. PMID:25923740

  16. Assessment of Antimicrobial and Antioxidant Activities of Nepeta trachonitica: Analysis of Its Phenolic Compounds Using HPLC-MS/MS

    PubMed Central

    Köksal, Ekrem; Tohma, Hatice; Kılıç, Ömer; Alan, Yusuf; Aras, Abdülmelik; Gülçin, İlhami; Bursal, Ercan

    2017-01-01

    Continuing our work on the sources of natural bioactive compounds, we evaluated the antimicrobial and antioxidant activities of Nepeta trachonitica as well as its major phenolic content using the high-performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) technique. For antioxidant activity, ferric reducing antioxidant power (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) methods were performed to measure the reducing power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was employed to evaluate the radical scavenging activity of the sample. For antimicrobial activity, three Gram-positive and four Gram-negative microbial species as well as three fungi species were tested. N. trachonitica appeared to have reasonable antioxidant activity and decent antimicrobial activity as indicated by the inhibition of the organisms’ growth. The most susceptible species were Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 11229 among the organisms tested. Ethanol extract of the plant has the highest effect on Saccharomyces cerevisiae but no effect on Yarrowia lipolytica. The HPLC-MS/MS analysis showed that at least 11 major phenolic compounds of N. trachonitica exist, the major ones being rosmarinic acid, chlorogenic acid and quinic acid. The obtained results suggest that N. trachonitica could be a promising source for food and nutraceutical industries because of its antimicrobial and antioxidant properties and phenolic compounds. PMID:28505129

  17. A novel UPLC-MS/MS method for sensitive quantitation of boldine in plasma, a potential anti-inflammatory agent: application to a pharmacokinetic study in rats.

    PubMed

    Zeng, Rong-Jie; Li, Yu; Chen, Jian-Zhong; Chou, Gui-Xin; Gao, Yu; Shao, Jing-Wei; Jia, Lee; Wu, Sheng-Dong; Wu, Shui-Sheng

    2015-03-01

    Boldine is a potential anti-inflammatory agent found in several different plants. Published bioanalytical methods using HPLC with ultraviolet and fluorescent detection lacked enough sensitivity and required tedious sample preparation procedures. Herein, we describe the development of a novel ultra-high performance LC with MS/MS for determination of boldine in plasma. Boldine in plasma was recovered by liquid-liquid extraction using 1 mL of methyl tert-butyl ether. Chromatographic separation was performed on a C18 column at 45°C, with a gradient elution consisting of acetonitrile and water containing 0.1% (v/v) formic acid at a flow rate of 0.3 mL/min. The detection was performed on an electrospray triple-quadrupole MS/MS by positive ion multiple reaction monitoring mode. Good linearity (r(2) > 0.9926) was achieved in a concentration range of 2.555-2555 ng/mL with a lower limit of quantification of 2.555 ng/mL for boldine. The intra- and inter-day precisions of the assay were 1.2-6.0 and 1.8-7.4% relative standard deviation with an accuracy of -6.0-8.0% relative error. This newly developed method was successfully applied to a single low-dose pharmacokinetic study in rats and was demonstrated to be simpler and more sensitive than the published methods, allowing boldine quantification in reduced plasma volume. Copyright © 2014 John Wiley & Sons, Ltd.

  18. A UPLC-MS/MS method for simultaneous determination of five flavonoids from Stellera chamaejasme L. in rat plasma and its application to a pharmacokinetic study.

    PubMed

    Li, Yun-Qing; Li, Cheng-Jian; Lv, Lei; Cao, Qing-Qing; Qian, Xian; Li, Si Wei; Wang, Hui; Zhao, Liang

    2018-06-01

    Stellera chamaejasme L. has been used as a traditional Chinese medicine for the treatment of scabies, tinea, stubborn skin ulcers, chronic tracheitis, cancer and tuberculosis. A sensitive and selective ultra-high liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous determination of five flavonoids (stelleranol, chamaechromone, neochamaejasmin A, chamaejasmine and isochamaejasmin) of S. chamaejasme L. in rat plasma. Chromatographic separation was accomplished on an Agilent Poroshell 120 EC-C 18 column (2.1 × 100 mm, 2.7 μm) with gradient elution at a flow rate of 0.4 mL/min and the total analysis time was 7 min. The analytes were detected using multiple reaction monitoring in positive ionization mode. The samples were prepared by liquid-liquid extraction with ethyl acetate. The UPLC-MS/MS method was validated for specificity, linearity, sensitivity, accuracy and precision, recovery, matrix effect and stability. The validated method exhibited good linearity (r ≥ 0.9956), and the lower limits of quantification ranged from 0.51 to 0.64 ng/mL for five flavonoids. The intra- and inter-day precision were both <10.2%, and the accuracy ranged from -11.79 to 9.21%. This method was successfully applied to a pharmacokinetic study of five flavonoids in rats after oral administration of ethyl acetate extract of S. chamaejasme L. Copyright © 2018 John Wiley & Sons, Ltd.

  19. Factors Associated with Neurologists' Provision of MS Patient Care

    PubMed Central

    Halpern, Michael T.; Teixeira-Poit, Stephanie M.; Kane, Heather; Frost, Corey; Keating, Michael; Olmsted, Murrey

    2014-01-01

    Neurologists are central to providing quality care for individuals with MS. However, neurologist shortages may restrict access to care for MS patients. To examine factors influencing neurologists' provision of MS care, we surveyed 1,700 US neurologists to assess demographic/practice characteristics, training, and attitudes toward MS care. The study population consisted of 573 respondents: 87 (15.2%) MS subspecialists and 486 (84.8%) “other neurologists,” including subspecialists in other neurology areas (i.e., non-MS) and general neurologists. MS subspecialists indicating they “enjoy interacting with MS patients” had a significantly greater rate of MS patients seen per week. In separate analyses of the “other neurologists” group, the rate of MS patients seen was lower among neurologists in university-based groups or those practicing in major cities; female neurologists; and neurologists who indicated lack of sufficient knowledge regarding MS patient care. Rates of MS patients seen were significantly greater for other neurologists who agreed that MS care involved “ability to improve patient outcomes and quality of life”; “dynamic area with evolving treatment options”; and “enjoy interacting with MS patients.” Understanding factors influencing MS patient care by neurologists and developing policies for appropriate access to care is critical for optimal outcomes among this population. PMID:24949203

  20. Quantitative Acylcarnitine Determination by UHPLC-MS/MS – Going Beyond Tandem MS Acylcarnitine “Profiles”

    PubMed Central

    Minkler, Paul E.; Stoll, Maria S.K.; Ingalls, Stephen T.; Kerner, Janos; Hoppel, Charles L.

    2016-01-01

    Tandem MS “profiling” of acylcarnitines and amino acids was conceived as a first-tier screening method, and its application to expanded newborn screening has been enormously successful. However, unlike amino acid screening (which uses amino acid analysis as its second-tier validation of screening results), acylcarnitine “profiling” also assumed the role of second-tier validation, due to the lack of a generally accepted second-tier acylcarnitine determination method. In this report, we present results from the application of our validated UHPLC-MS/MS second-tier method for the quantification of total carnitine, free carnitine, butyrobetaine, and acylcarnitines to patient samples with known diagnoses: malonic acidemia, short-chain acyl-CoA dehydrogenase deficiency (SCADD) or isobutyryl-CoA dehydrogenase deficiency (IBD), 3-methyl-crotonyl carboxylase deficiency (3-MCC) or β-ketothiolase deficiency (BKT), and methylmalonic acidemia (MMA). We demonstrate the assay’s ability to separate constitutional isomers and diastereomeric acylcarnitines and generate values with a high level of accuracy and precision. These capabilities are unavailable when using tandem MS “profiles”. We also show examples of research interest, where separation of acylcarnitine species and accurate and precise acylcarnitine quantification is necessary. PMID:26458767

  1. DETERMINATION OF ECOLOGICALLY RELEVANT PHARMACEUTICALS AND THEIR SELECTED METABOLITES IN EFFLUENT AND SURFACE WATER USING UPLC/MS/MS

    EPA Science Inventory

    Objective is to develop analytical methods including SPE and UPLC/MS/MS needed to analyze over 60 human prescription pharamceuticals and metabolites belonging to a multitude of different classes in surface waters and wastewater effluent. The methods will be used in future studies...

  2. An LC-IMS-MS Platform Providing Increased Dynamic Range for High-Throughput Proteomic Studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baker, Erin Shammel; Livesay, Eric A.; Orton, Daniel J.

    2010-02-05

    A high-throughput approach and platform using 15 minute reversed-phase capillary liquid chromatography (RPLC) separations in conjunction with ion mobility spectrometry-mass spectrometry (IMS-MS) measurements was evaluated for the rapid analysis of complex proteomics samples. To test the separation quality of the short LC gradient, a sample was prepared by spiking twenty reference peptides at varying concentrations from 1 ng/mL to 10 µg/mL into a tryptic digest of mouse blood plasma and analyzed with both a LC-Linear Ion Trap Fourier Transform (FT) MS and LC-IMS-TOF MS. The LC-FT MS detected thirteen out of the twenty spiked peptides that had concentrations ≥100 ng/mL.more » In contrast, the drift time selected mass spectra from the LC-IMS-TOF MS analyses yielded identifications for nineteen of the twenty peptides with all spiking level present. The greater dynamic range of the LC-IMS-TOF MS system could be attributed to two factors. First, the LC-IMS-TOF MS system enabled drift time separation of the low concentration spiked peptides from the high concentration mouse peptide matrix components, reducing signal interference and background, and allowing species to be resolved that would otherwise be obscured by other components. Second, the automatic gain control (AGC) in the linear ion trap of the hybrid FT MS instrument limits the number of ions that are accumulated to reduce space charge effects, but in turn limits the achievable dynamic range compared to the TOF detector.« less

  3. An LC-MS/MS method for simultaneous determination of three Polygala saponin hydrolysates in rat plasma and its application to a pharmacokinetic study.

    PubMed

    Wang, Qian; Xiao, Bing-Xin; Pan, Rui-Le; Liu, Xin-Min; Liao, Yong-Hong; Feng, Li; Cao, Fang-Rui; Chang, Qi

    2015-07-01

    Radix Polygala has a long history of use as a sedative in traditional Chinese medicine and its major ingredients are saponins, which are recognized effective in memory improvement but highly toxic to gastricintestinal mucosa. Polygala saponin hydrolysates (PSH), an alkaline hydrolysis product and also the intestinal metabolites of the saponins, exhibited stronger effects in improving memory of mice and had less toxicity than its original saponins. The present study aims to develop a sensitive LC-MS/MS method for simultaneously determining PSH three major active components, 3,4,5-trimethoxycinnamylic acid (TMCA), p-methoxycinnamylic acid (PMCA) and tenuifolin (TF), in rat plasma and apply the method to a pharmacokinetic study. The acidic plasma (100μl) was treated by liquid-liquid extraction with ethyl acetate and reconstituted sample was analyzed on a C18 column eluted with acetonitrile-water (50:50) containing 0.2% formic acid at 0.4ml/min. The mass detection in negative electrospray ionization was used. The ion pairs for multiple reaction monitoring were set at m/z 237.0/103.0, 177.0/116.6 and 679.5/425.3 for TMCA, PMCA and TF, respectively. Their pharmacokinetic profiles were studied in rats after intravenous and oral dose of PSH at 20 and 100mg/kg, respectively. The calibration curves had good linearity (r(2)>0.99) for TMCA, PMCA and TF within the tested concentration ranges. The limits of detection and quantification were 1, 10, 0.5ng/ml and 10.0, 20.0, 1.0ng/ml, respectively. The intra-day and inter-day precisions were less than 18.9% and accuracies between 93.2% and 113.3%, and the extraction recovery ranged from 91.2% to 112.1% for all analytes. The pharmacokinetic study showed that TMCA, PMCA and TF could be rapidly absorbed into the circulation and reached their peak concentrations at about 9.1, 9.0 and 24.0min, respectively. TF had a lower oral bioavailability (2.0%) than TMCA (90.1%) and PMCA (96.5%), but it remained in the body much longer (t1/2,

  4. Pharmacokinetic profile of bilberry anthocyanins in rats and the role of glucose transporters: LC-MS/MS and computational studies.

    PubMed

    Baron, G; Altomare, A; Regazzoni, L; Redaelli, V; Grandi, S; Riva, A; Morazzoni, P; Mazzolari, A; Carini, M; Vistoli, G; Aldini, G

    2017-09-10

    The aim of the present investigation was to better understand the pharmacokinetic profile of bilberry (Vaccinium Myrtillus) anthocyanins and the role of glucose transporters (sGLT1 and GLUT2) on their absorption. In particular, the absorption of 15 different anthocyanins contained in a standardized bilberry extract (Mirtoselect ® ) was measured in rats by a validated LC-ESI-MS/MS approach. The plasma concentration peak (Cmax) of 11.1ng/mL was reached after 30min and fasting condition significantly increased the bioavailability of anthocyanins by more than 7 fold in respect to fed rats. Glucose co-administration did not interfere with the overall anthocyanin uptake. Bioavailability of each anthocyanin was then estimated by comparing the relative content in plasma vs extract. The 15 anthocyanins behaved differently in term of bioavailability and both the aglycone and the sugar moiety were found to affect the absorption. For instance, arabinoside moiety was detrimental while cyanidin enhanced bioavailability. Computational studies permitted to rationalize such results, highlighting the role of glucose transporters (sGLT1 and GLUT2) in anthocyanins absorption. In particular a significant correlation was found for the 15 anthocyanins between sGLT1 and GLUT2 recognition and absorption. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. An Observational Study to Assess Brain MRI Change and Disease Progression in Multiple Sclerosis Clinical Practice-The MS-MRIUS Study.

    PubMed

    Zivadinov, Robert; Khan, Nasreen; Medin, Jennie; Christoffersen, Pia; Price, Jennifer; Korn, Jonathan R; Bonzani, Ian; Dwyer, Michael G; Bergsland, Niels; Carl, Ellen; Silva, Diego; Weinstock-Guttman, Bianca

    2017-05-01

    To describe methodology, interim baseline, and longitudinal magnetic resonance imaging (MRI) acquisition parameter characteristics of the multiple sclerosis clinical outcome and MRI in the United States (MS-MRIUS). The MS-MRIUS is an ongoing longitudinal and retrospective study of MS patients on fingolimod. Clinical and brain MRI image scan data were collected from 600 patients across 33 MS centers in the United States. MRI brain outcomes included change in whole-brain volume, lateral ventricle volume, T2- and T1-lesion volumes, and new/enlarging T2 and gadolinium-enhancing lesions. Interim baseline and longitudinal MRI acquisition parameters results are presented for 252 patients. Mean age was 44 years and 81% were female. Forty percent of scans had 3-dimensional (3D) T1 sequence in the preindex period, increasing to 50% in the postindex period. Use of 2-dimensional (2D) T1 sequence decreased over time from 85% in the preindex period to 65% in the postindex. About 95% of the scans with FLAIR and 2D T1-WI were considered acceptable or good quality compared to 99-100% with 3D T1-WI. There were notable changes in MRI hardware, software, and coil (39.5% in preindex to index and 50% in index to postindex). MRI sequence parameters (orientation, thickness, or protocol) differed for 36%, 29%, and 20% of index/postindex scans for FLAIR, 2D T1-WI, and 3D T1-WI, respectively. The MS-MRIUS study linked the clinical and brain MRI outcomes into an integrated database to create a cohort of fingolimod patients in real-world practice. Variability was observed in MRI acquisition protocols overtime. © 2016 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

  6. Determination of a novel anticancer c-Met inhibitor LS-177 in rat plasma and tissues with a validated UPLC-MS/MS method: application to pharmacokinetics and tissue distribution study.

    PubMed

    Ju, Ping; Liu, Zhenzhen; Jiang, Yu; Zhao, Simin; Zhang, Lunhui; Zhang, Yuanyuan; Gu, Liqiang; Tang, Xing; Bi, Kaishun; Chen, Xiaohui

    2015-07-01

    LS-177 is a novel small-molecule kinase inhibitor employed to interrupt the c-Met signaling pathway. A rapid and sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of LS-177 in rat plasma and tissues. The biosamples were extracted by liquid-liquid extraction with methyl tert-butyl ether and separated on a C18 column (50 × 4.6 mm, 2.6 µm) using a gradient elution mobile phase consisting of acetonitrile-0.1% formic acid water. Under the optimal conditions, the selectivity of the method was satisfactory with no endogenous interference. The intraday and interday precisions (relative standard deviation) were <10.5% and the accuracy (relative error) was from -12.5 to 12.5% at all quality control levels. Excellent recovery and negligible matrix effects were observed. Stability studies showed that LS-177 was stable during the preparation and analytical processes. The UPLC-MS/MS method was successfully applied to pharmacokinetic and tissue distribution studies. The results indicated that there was no significant drug accumulation after multiple-dose oral administration of LS-177. The tissue distribution study exhibited significant higher uptakes of LS-177 in stomach, intestine, lung and liver among all of the tissues. The results in pharmacokinetics and tissue distribution may provide a meaningful basis for clinical application. Copyright © 2014 John Wiley & Sons, Ltd.

  7. A validated HPLC-MS/MS assay for quantifying unstable pharmacologically active metabolites of clopidogrel in human plasma: application to a clinical pharmacokinetic study.

    PubMed

    Furlong, Michael T; Savant, Ishani; Yuan, Moucun; Scott, Laura; Mylott, William; Mariannino, Thomas; Kadiyala, Pathanjali; Roongta, Vikram; Arnold, Mark E

    2013-05-01

    Clopidogrel is prescribed for the treatment of Acute Coronary Syndrome and recent myocardial infarction, recent stroke, or established peripheral arterial disease. A sensitive and reliable high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) assay was developed and validated to enable reliable quantification of four diastereomeric and chemically reactive thiol metabolites, two of which are pharmacologically active, in human plasma. The metabolites were stabilized by alkylation of their reactive thiol moieties with 2-bromo-3'-methoxyacetophenone (MPB). Following organic solvent mediated-protein precipitation in a 96-well plate format, chromatographic separation was achieved by gradient elution on an Ascentis Express RP-amide column. Chromatographic conditions were optimized to ensure separation of the four derivatized active metabolites. Derivatized metabolites and stable isotope-labeled internal standards were detected by positive ion electrospray tandem mass spectrometry. The HPLC-MS/MS assay was validated over concentration ranges of 0.125-125 ng/mL for metabolites H1-H3 and 0.101-101 ng/mL for H4. Intra- and inter-assay precision values for replicate quality control samples were within 14.3% for all analytes during the assay validation. Mean quality control accuracy values were within ±6.3% of nominal values for all analytes. Assay recoveries were high (>79%). The four derivatized analytes were stable in human blood for at least 2 h at room temperature and on ice. The analytes were also stable in human plasma for at least 25 h at room temperature, 372 days at -20 °C and -70 °C, and following at least five freeze-thaw cycles. The validated assay was successfully applied to the quantification of all four thiol metabolites in human plasma in support of a human pharmacokinetic study. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Simultaneous quantification of the organophosphorus pesticides dimethoate and omethoate in porcine plasma and urine by LC-ESI-MS/MS and flow-injection-ESI-MS/MS.

    PubMed

    John, Harald; Eddleston, Michael; Clutton, R Eddie; Worek, Franz; Thiermann, Horst

    2010-05-15

    Dimethoate is an organophosphorus toxicant used in agri- and horticulture as a systemic broad-spectrum insecticide. It also exhibits toxic activity towards mammalian organism provoked by catalytic desulfuration in the liver producing its oxon-derivative omethoate thus inhibiting acetylcholinesterase, initiating cholinergic crisis and ultimately leading to death by respiratory paralysis and cardiovascular collapse. Pharmaco- and toxicokinetic studies in animal models help to broaden basic understanding of medical intervention by antidotes and supportive care. Therefore, we developed and validated a LC-ESI-MS/MS method suitable for the simultaneous, selective, precise (RSD(intra-day) 1-8%; RSD(inter-day) 5-14%), accurate (intra-day: 95-107%; inter-day: 90-115%), and robust quantification of both pesticides from porcine urine and plasma after deproteinization by precipitation and extensive dilution (1:11,250 for plasma and 1:40,000 for urine). Accordingly, lower limits of quantification (0.24-0.49 microg/ml plasma and 0.78-1.56 microg/ml urine) and lower limits of detection (0.12-0.24 microg/ml plasma and 0.39-0.78 microg/ml urine) were equivalent to quite low absolute on-column amounts (1.1-2.1 pg for plasma and 2.0-3.9 pg for urine). The calibration range (0.24-250 microg/ml plasma and 0.78-200 microg/ml urine) was subdivided into two linear ranges (r(2)>or=0.998) each covering nearly two orders of magnitude. The lack of any interfering peak in 6 individual blank specimens from plasma and urine demonstrated the high selectivity of the method. Furthermore, extensive sample dilution causing lowest concentration of potentially interfering matrix ingredients prompted us to develop and validate an additional flow-injection method (FI-ESI-MS/MS). Validation characteristics were as good as for the chromatographic method but sample throughput was enhanced by a factor of 6. Effects on ionization provoked by plasma and urine matrix from 6 individuals as well as in the

  9. Metabolite profiling in Trigonella seeds via UPLC-MS and GC-MS analyzed using multivariate data analyses.

    PubMed

    Farag, Mohamed A; Rasheed, Dalia M; Kropf, Matthias; Heiss, Andreas G

    2016-11-01

    Trigonella foenum-graecum is a plant of considerable value for its nutritive composition as well as medicinal effects. This study aims to examine Trigonella seeds using a metabolome-based ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) in parallel to gas chromatography-mass spectrometry (GC-MS) coupled with multivariate data analyses. The metabolomic differences of seeds derived from three Trigonella species, i.e., T. caerulea, T. corniculata, and T. foenum-graecum, were assessed. Under specified conditions, we were able to identify 93 metabolites including 5 peptides, 2 phenolic acids, 22 C/O-flavonoid conjugates, 26 saponins, and 9 fatty acids using UPLC-MS. Several novel dipeptides, saponins, and flavonoids were found in Trigonella herein for the first time. Samples were classified via unsupervised principal component analysis (PCA) followed by supervised orthogonal projection to latent structures-discriminant analysis (OPLS-DA). A distinct separation among the investigated Trigonella species was revealed, with T. foenum-graecum samples found most enriched in apigenin-C-glycosides, viz. vicenins 1/3 and 2, compared to the other two species. In contrast to UPLC-MS, GC-MS was less efficient to classify specimens, with differences among specimens mostly attributed to fatty acyl esters. GC-MS analysis of Trigonella seed extracts led to the identification of 91 metabolites belonging mostly to fatty acyl esters, free fatty acids followed by organic acids, sugars, and amino acids. This study presents the first report on primary and secondary metabolite compositional differences among Trigonella seeds via a metabolomics approach and reveals that, among the species examined, the official T. foenum-graecum presents a better source of Trigonella secondary bioactive metabolites.

  10. Simultaneous analysis of 17 diuretics in dietary supplements by HPLC and LC-MS/MS.

    PubMed

    Woo, H; Kim, J W; Han, K M; Lee, J H; Hwang, I S; Lee, J H; Kim, J; Kweon, S J; Cho, S; Chae, K R; Han, S Y; Kim, J

    2013-01-01

    In order to test health foods for illegally added diuretics for weight loss, we developed simple, rapid, selective, and sensitive methods using HPLC and LC-MS/MS for the simultaneous analysis of 17 diuretics in dietary supplements. HPLC conditions were set with a Capcell-pak C18, using a mobile phase consisting of gradient conditions, UV detection at 254 nm and validated for linearity (r(2)> 0.999), precision (CV ≤ 3%), recoveries (90.4-102.8%) and reproducibility. Identification and quantification of 17 diuretics were accomplished by ion-spray LC-MS/MS using multiple reaction monitoring (MRM). The chromatographic separation was carried out under the reversed-phase mechanism on an HSS-T3 column. The LC-MS/MS method was validated for linearity (r(2)> 0.99) and precision (CV < 13%). Sixteen dietary supplements were tested with the developed methods. Diuretics were not detected in all samples. Extraction recovery was also investigated and the extraction recoveries in different formulations were from 88% to 110% and from 81% to 116% using HPLC and LC-MS/MS, respectively. There was no significant difference in recoveries in the type of dietary supplements. Based on this result, the developed methods to monitor illegal drug adulterations in dietary supplements using HPLC and LC-MS/MS are simple, fast and reliable. Therefore, it is applicable to routine drug-adulteration screening.

  11. Rapid glucosinolate detection and identification using accurate mass MS-MS

    USDA-ARS?s Scientific Manuscript database

    Currently, there is a demand for accurate evaluation of brassica plat species for their glucosinolate content. An optimized method has been developed for detecting and identifying glucosinolates in plant extracts using MS-MS fragmentation with ion trap collision induced dissociation (CID) and higher...

  12. Offline pentafluorophenyl (PFP)-RP prefractionation as an alternative to high-pH RP for comprehensive LC-MS/MS proteomics and phosphoproteomics.

    PubMed

    Grassetti, Andrew V; Hards, Rufus; Gerber, Scott A

    2017-07-01

    Technological advances in liquid chromatography and tandem mass spectrometry (LC-MS/MS) have enabled comprehensive analyses of proteins and their post-translational modifications from cell culture and tissue samples. However, sample complexity necessitates offline prefractionation via a chromatographic method that is orthogonal to online reversed-phase high-performance liquid chromatography (RP-HPLC). This additional fractionation step improves target identification rates by reducing the complexity of the sample as it is introduced to the instrument. A commonly employed offline prefractionation method is high pH reversed-phase (Hi-pH RP) chromatography. Though highly orthogonal to online RP-HPLC, Hi-pH RP relies on buffers that interfere with electrospray ionization. Thus, samples that are prefractionated using Hi-pH RP are typically desalted prior to LC-MS/MS. In the present work, we evaluate an alternative offline prefractionation method, pentafluorophenyl (PFP)-based reversed-phase chromatography. Importantly, PFP prefractionation results in samples that are dried prior to analysis by LC-MS/MS. This reduction in sample handling relative to Hi-pH RP results in time savings and could facilitate higher target identification rates. Here, we have compared the performances of PFP and Hi-pH RP in offline prefractionation of peptides and phosphopeptides that have been isolated from human cervical carcinoma (HeLa) cells. Given the prevalence of isobaric mass tags for peptide quantification, we evaluated PFP chromatography of peptides labeled with tandem mass tags. Our results suggest that PFP is a viable alternative to Hi-pH RP for both peptide and phosphopeptide offline prefractionation.

  13. [UPLC-MS/MS determination of content of three iridoids of xingnaojing oral preparation in rat brains and study on their brain pharmacokinetics].

    PubMed

    Xu, Pan; Du, Shou-Ying; Lu, Yang; Bai, Jie; Liu, Hui-Min; Du, Qiu; Chen, Zhen-Zhen; Wang, Zhen

    2014-06-01

    To establish a UPLC-MS/MS method for the simultaneous determination of geniposide, genipin 1-O-beta-D-gentiobioside and geniposidic acid in rat brains and study the brain pharmacokinetics of the three iridoid glycosides in stroke rat after the oral administration of Xingnaojing. In this experiment, brain samples were precipitated with protein for twice. Acquity BEH C18 column was adopted, with acetonitrile-0.1% formic acid-water as the mobile phase for gradient elution. ESI source was adopted for mass spectra; multiple reaction monitoring (MRM) was conducted to detect negative ions. The time for sample analysis was 3.5 min. the results showed good linear relations among the three iridoid glycosides, with the extraction recovery between 99.6% and 114.3%, good intra- and inter-day precisions and accuracies and stability in line with the requirements. The t1/2 and MRT in the three components were similar in brains of stroke rats. Geniposide and genipin 1-O-beta-D-gentiobioside showed double peaks; where as geniposidic acid showed a single peak. In conclusion, the method is so specific, sensitive, accurate and reliable that it can be used to study the brain pharmacokinetics of Xingnaojing oral preparation.

  14. Quantifying MMA by SLE LC-MS/MS: Unexpected challenges in assay development.

    PubMed

    Lo, Sheng-Ying; Gordon, Cindy; Sadilkova, Katerina; Jack, Rhona M; Dickerson, Jane A

    2016-09-01

    Analysis of serum/plasma methylmalonic acid (MMA) is important for the diagnosis and management of methylmalonic acidemia in pediatric populations. This work focuses on developing and validating a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to monitor methylmalonic acidemia using a simple method preparation. MMA and stable isotope labeled d3-MMA was extracted using supported liquid extraction (SLE). Assay imprecision, bias, linearity, recovery and carryover were determined. The relationship between MMA and propionyl acylcarnitine (C3-acylcarnitine) was also evaluated using historical paired results from 51 unique individuals. Baseline separation between MMA and succinic acid was completed in 7min. The assay was linear from 0.1 to 500μM. The intra-day and inter-day imprecision CV ranged from 4.1 to 13.2% (0.3 to 526μM) and 5.0 to 15.7% (0.3 to 233μM), respectively. Recovery ranged from 93 to 125%. The correlation with a national reference laboratory LC-MS/MS assay showed a Deming regression of 1.026 and intercept of -1.335. Carryover was determined to be <0.04%. Patient-specific correlation was observed between MMA and C3-acylcarnitine. This report describes the first LC-MS/MS method using SLE for MMA extraction. In addition, we illustrate the challenges encountered during this method development that should be assessed and resolved by any laboratory implementing a SLE LC-MS/MS assay designed to quantify analytes across several orders of magnitude. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  15. Simultaneous determination of centchroman and tamoxifen along with their metabolites in rat plasma using LC-MS/MS.

    PubMed

    Rama Raju, Kanumuri Siva; Taneja, Isha; Singh, Sheelendra Pratap; Tripathi, Amit; Mishra, Durga Prasad; Hussain, K Mahaboob; Gayen, Jiaur Rahman; Singh, Shio Kumar; Wahajuddin, Muhammad

    2015-01-01

    Tamoxifen and centchroman are two non-steroidal, selective estrogen receptors modulators, intended for long term therapy in the woman. Because of their wide spread use, there is a possibility of co-prescription of these agents. We studied the probable pharmacokinetic interaction between these agents in breast cancer model rats. A simple, sensitive and rapid LC-ESI-MS/MS method was developed and validated for the simultaneous determination of tamoxifen, centchroman and their active metabolites. The method was linear over a range of 0.2-200 ng/ml. All validation parameters met the acceptance criteria according to regulatory guidelines. LC-MS/MS method for determination of tamoxifen, centchroman and their metabolites was developed and validated. Results show the potential of drug-drug interaction upon co-administration these two marketed drugs.

  16. Measuring fecal testosterone in females and fecal estrogens in males: comparison of RIA and LC/MS/MS methods for wild baboons (Papio cynocephalus)

    PubMed Central

    Gesquiere, Laurence R.; Ziegler, Toni E.; Chen, Patricia A.; Epstein, Katherine A.; Alberts, Susan C.; Altmann, Jeanne

    2014-01-01

    The development of non-invasive methods, particularly fecal determination, has made possible the assessment of hormone concentrations in wild animal populations. However, measuring fecal metabolites needs careful validation for each species and for each sex. We investigated whether radioimmunoassays (RIAs) previously used to measure fecal testosterone (fT) in male baboons and fecal estrogens (fE) in female baboons were well suited to measure these hormones in the opposite sex. We compared fE and fT concentrations determined by RIA to those measured by liquid chromatography combined with triple quadropole mass spectrometry (LC/MS/MS), a highly specific method. Additionally, we conducted a biological validation to assure that the measurements of fecal concentrations reflected physiological levels of the hormone of interest. Several tests produced expected results that led us to conclude that our RIAs can reliably measure fT and fE in both sexes, and that within-sex comparisons of these measures are valid: (i) fTRIA were significantly correlated to fTLC/MS/MS for both sexes; (ii) fTRIA were higher in adult than in immature males; (iii) fTRIA were higher in pregnant than non-pregnant females; (iv) fERIA were correlated with 17β-estradiol (fE2) and with estrone (fE1) determined by LC/MS/MS in pregnant females; (v) fERIA were significantly correlated with fE2 in non-pregnant females and nearly significantly correlated in males; (vi) fERIA were higher in adult males than in immature males. fERIA were higher in females than in males, as predicted, but unexpectedly, fTRIA were higher in females than in males, suggesting a difference in steroid metabolism in the two sexes; consequently, we conclude that while within-sex comparisons are valid, fTRIA should not be used for intersexual comparisons. Our results should open the field to important additional studies, as to date the roles of testosterone in females and estrogens in males have been little investigated. PMID

  17. EXTRACTION AND DETECTION OF A NEW ARSINE SULFIDE CONTAINING ARSENOSUGAR IN MOLLUSCS BY IC-ICP-MS AND IC-ESI-MS/MS

    EPA Science Inventory

    Using IC-ICP-MS and IC-ESI-MS/MS, an unknown arsenical compound in mollusks has been identified as a new arsine sulfide containing analog of a known arsenosugar and is referred to as As(498). This species has been observed in four separate shellfish species following a mild metha...

  18. Improved mb-Ms Discrimination Using mb(P-coda) and MsU with Application to the Six North Korean Nuclear Tests

    NASA Astrophysics Data System (ADS)

    Napoli, V.; Yoo, S. H.; Russell, D. R.

    2017-12-01

    To improve discrimination of small explosions and earthquakes, we developed a new magnitude scale based on the standard Ms:mb discrimination method. In place of 20 second Ms measurements we developed a unified Rayleigh and Love wave magnitude scale (MsU) that is designed to maximize available information from single stations and then combine magnitude estimates into network averages. Additionally, in place of mb(P) measurements we developed an mb(P-Coda) magnitude scale as the properties of the coda make sparse network mb(P-Coda) more robust and less variable than network mb(P) estimates. A previous mb:MsU study conducted in 2013 in the Korean Peninsula shows that the use of MsU in place of standard 20 second Ms, leads to increased population separation and reduced scattering. The goals of a combined mb(P-coda):MsU scale are reducing scatter, ensuring applicability at small magnitudes with sparse networks, and improving the overall distribution for mb:Ms earthquake and explosion populations. To test this method we are calculating mb(P-coda)and MsU for a catalog earthquakes located in and near the Korean Peninsula, for the six North Korean nuclear tests (4.1 < mb < 6.3) and for the 3 aftershocks to date that occurred after the sixth test (2.6 < ML < 4.0). Compared to the previous 2013 study, we expect to see greater separation in the populations and less scattering with the inclusion of mb(P-coda) and with the implementation of additional filters for MsU to improve signal-to-noise levels; this includes S-transform filtering for polarization and off-azimuth signal reduction at regional distances. As we are expanding our database of mb(P-coda):MsU measurements in the Korean Peninsula to determine the earthquake and explosion distribution, this research will address the limitations and potential for discriminating small magnitude events using sparse networks.

  19. Global mapping of rat plasma proteins with a native proteomic approach using nondenaturing micro 2DE and quantitative LC-MS/MS.

    PubMed

    Chen, Shumin; Wen, Meiling; Bu, Shujie; Wang, Ahui; Jin, Ya; Tan, Wen

    2016-12-01

    Plasma samples from adult male rats were separated by nondenaturing micro 2DE and a reference gel was selected, on which 136 CBB-stained spots were numbered and subjected to in-gel digestion and quantitative LC-MS/MS. The analysis provided the assignment of 1-25 (average eight) non-redundant proteins in each spot and totally 199 proteins were assigned in the 136 spots. About 40% of the proteins were detected in more than one spot and 15% in more than ten spots. We speculate this complexity arose from multiple causes, including protein heterogeneity, overlapping of protein locations and formation of protein complexes. Consequently, such results could not be appropriately presented as a conventional 2DE map, i.e. a list or a gel pattern with one or a few proteins annotated to each spot. Therefore, the LC-MS/MS quantity data was used to reconstruct the gel distribution of each protein and a library containing 199 native protein maps was established for rat plasma. Since proteins that formed a complex would migrate together during the nondenaturing 2DE and thus show similar gel distributions, correlation analysis was attempted for similarity comparison between the maps. The protein pairs showing high correlation coefficients included some well-known complexes, suggesting the promising application of native protein mapping for interaction analysis. With the importance of rat as the most commonly used laboratory animal in biomedical research, we expect this work would facilitate relevant studies by providing not only a reference library of rat plasma protein maps but a means for functional and interaction analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Simultaneous screening of targeted and non-targeted contaminants using an LC-QTOF-MS system and automated MS/MS library searching.

    PubMed

    Herrera-Lopez, S; Hernando, M D; García-Calvo, E; Fernández-Alba, A R; Ulaszewska, M M

    2014-09-01

    Simultaneous high-resolution full-scan and tandem mass spectrometry (MS/MS) analysis using time of flight mass spectrometry brings an answer for increasing demand of retrospective and non-targeted data analysis. Such analysis combined with spectral library searching is a promising tool for targeted and untargeted screening of small molecules. Despite considerable extension of the panel of compounds of tandem mass spectral libraries, the heterogeneity of spectral data poses a major challenge against the effective usage of spectral libraries. Performance evaluation of available LC-MS/MS libraries will significantly increase credibility in the search results. The present work was aimed to evaluate fluctuation of MS/MS pattern, in the peak intensities distribution together with mass accuracy measurements, and in consequence, performance compliant with ion ratio and mass error criteria as principles in identification processes for targeted and untargeted contaminants at trace levels. Matrix effect and ultra-trace levels of concentration (from 50 ng l(-1) to 1000 ng l(-1) were evaluated as potential source of inaccuracy in the performance of spectral matching. Matrix-matched samples and real samples were screened for proof of applicability. By manual review of data and application of ion ratio and ppm error criteria, false negatives were obtained; this number diminished when in-house library was used, while with on-line MS/MS databases 100% of positive samples were found. In our experience, intensity of peaks across spectra was highly correlated to the concentration effect and matrix complexity. In turn, analysis of spectra acquired at trace concentrations and in different matrices results in better performance in providing correct and reliable identification. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Wide-scope screening of pesticides in fruits and vegetables using information-dependent acquisition employing UHPLC-QTOF-MS and automated MS/MS library searching.

    PubMed

    Wang, Zhibin; Cao, Yanzhong; Ge, Na; Liu, Xiaomao; Chang, Qiaoying; Fan, Chunlin; Pang, Guo-Fang

    2016-11-01

    This paper presents an application of ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) for simultaneous screening and identification of 427 pesticides in fresh fruit and vegetable samples. Both full MS scan mode for quantification, and an artificial-intelligence-based product ion scan mode information-dependent acquisition (IDA) providing automatic MS to MS/MS switching of product ion spectra for identification, were conducted by one injection. A home-in collision-induced-dissociation all product ions accurate mass spectra library containing more than 1700 spectra was developed prior to actual application. Both qualitative and quantitative validations of the method were carried out. The result showed that 97.4 % of the pesticides had the screening detection limit (SDL) less than 50 μg kg -1 and more than 86.7 % could be confirmed by accurate MS/MS spectra embodied in the home-made library. Meanwhile, calibration curves covering two orders of magnitude were performed, and they were linear over the concentration range studied for the selected matrices (from 5 to 500 μg kg -1 for most of the pesticides). Recoveries between 80 and 110 % in four matrices (apple, orange, tomato, and spinach) at two spiked levels, 10 and 100 μg kg -1 , was 88.7 or 86.8 %. Furthermore, the overall relative standard deviation (RSD, n = 12) for 94.3 % of the pesticides in 10 μg kg -1 and 98.1 % of the pesticides in 100 μg kg -1 spiked levels was less than 20 %. In order to validate the suitability for routine analysis, the method was applied to 448 fruit and vegetable samples purchased in different local markets. The results show 83.3 % of the analyzed samples have positive findings (higher than the limits of identification and quantification), and 412 commodity-pesticide combinations are identified in our scope. The approach proved to be a cost-effective, time-saving and powerful strategy for routine large

  2. Sex-Based Differences in Multiple Sclerosis (MS): Part II: Rising Incidence of Multiple Sclerosis in Women and the Vulnerability of Men to Progression of this Disease.

    PubMed

    Dunn, Shannon E; Gunde, Eva; Lee, Hyunwoo

    2015-01-01

    It is well known that a number of autoimmune diseases including multiple sclerosis (MS) predominantly affect women and there has been much attention directed toward understanding why this is the case. Past research has revealed a number of sex differences in autoimmune responses that can account for the female bias in MS. However, much less is known about why the incidence of MS has increased exclusively in women over the past half century. The recency of this increase suggests that changing environmental or lifestyle factors are interacting with biological sex to increase MS risk predominantly in females. Indeed, a number of recent studies have identified sex-specific differences in the effect of environmental factors on MS incidence. The first part of this chapter will overview this evidence and will discuss the possible scenarios of how the environment may be interacting with autoimmune mechanisms to contribute to the preferential rise in MS incidence in women. Despite the strong female bias in MS incidence, culminating evidence from natural history studies, and imaging and pathology studies suggests that males who develop MS may exhibit a more rapid decline in disability and cognitive functioning than women. Very little is known about the biological basis of this more rapid deterioration, but some insights have been provided by studies in rodent models of demyelination/remyelination. The second part of this chapter will overview the evidence that males with relapsing-onset MS undergo a more rapid progression of disease than females and will discuss potential biological mechanisms that account for this sex difference.

  3. IsoMS: automated processing of LC-MS data generated by a chemical isotope labeling metabolomics platform.

    PubMed

    Zhou, Ruokun; Tseng, Chiao-Li; Huan, Tao; Li, Liang

    2014-05-20

    A chemical isotope labeling or isotope coded derivatization (ICD) metabolomics platform uses a chemical derivatization method to introduce a mass tag to all of the metabolites having a common functional group (e.g., amine), followed by LC-MS analysis of the labeled metabolites. To apply this platform to metabolomics studies involving quantitative analysis of different groups of samples, automated data processing is required. Herein, we report a data processing method based on the use of a mass spectral feature unique to the chemical labeling approach, i.e., any differential-isotope-labeled metabolites are detected as peak pairs with a fixed mass difference in a mass spectrum. A software tool, IsoMS, has been developed to process the raw data generated from one or multiple LC-MS runs by peak picking, peak pairing, peak-pair filtering, and peak-pair intensity ratio calculation. The same peak pairs detected from multiple samples are then aligned to produce a CSV file that contains the metabolite information and peak ratios relative to a control (e.g., a pooled sample). This file can be readily exported for further data and statistical analysis, which is illustrated in an example of comparing the metabolomes of human urine samples collected before and after drinking coffee. To demonstrate that this method is reliable for data processing, five (13)C2-/(12)C2-dansyl labeled metabolite standards were analyzed by LC-MS. IsoMS was able to detect these metabolites correctly. In addition, in the analysis of a (13)C2-/(12)C2-dansyl labeled human urine, IsoMS detected 2044 peak pairs, and manual inspection of these peak pairs found 90 false peak pairs, representing a false positive rate of 4.4%. IsoMS for Windows running R is freely available for noncommercial use from www.mycompoundid.org/IsoMS.

  4. Effectiveness of the anaesthetic MS-222 in gilthead seabream, Sparus aurata: effect of feeding time and day-night variations in plasma MS-222 concentration and GST activity.

    PubMed

    Vera, L M; Montoya, A; Sánchez-Vázquez, F J

    2013-02-17

    Feeding time is a potent zeitgeber capable of synchronising behavioural and physiological daily rhythms in fish. However, the effect of feeding time on the daily rhythm of drugs toxicity and/or effectiveness remains unexplored to date. In this paper we investigated the day/night variations in the effectiveness of an anaesthetic commonly used in fish (Tricaine, MS-222) in a teleost of great chronobiological and aquaculture interest (gilthead seabream). To this end, fish were kept under LD 12:12 and fed at mid-light (ML), mid-darkness (MD) or random times (RD). The time needed to induce anaesthesia (reduction of locomotor activity) during MS-222 exposure (65 mg/L) as well as the recovery period were investigated at ML and MD in the three experimental groups using specialised video tracking software. In addition, daily rhythms of GST activity in the liver (as an indicator of detoxification processes) and plasma MS-222 concentration (related to uptake) were determined. The results revealed that MS-222 effectiveness in the ML group was higher during the day than at night (significant reduction of activity after 3 min vs. 5 min) whereas in the MD group, the daily variation of MS-222 effectiveness was inverted (significant reduction of activity after 7 min at ML vs. 2 min at MD), suggesting that feeding time can shift the day-night variations in the effectiveness of MS-222. Hepatic GST also seemed to be affected by feeding time: in fish fed at MD or RD this enzyme activity showed significant differences during the day, and the highest levels were found at different times of the day in each group. Plasma MS-222 concentrations were higher at ML (142.4±12.8 ng/ml) than at MD (96.3±10.9 ng/ml) (t-Student, p<0.05). These results suggest that the daily variation in MS-222 concentration following exposure might be involved, among other factors, in the existence of day-night variations in the effectiveness of this anaesthetic. Furthermore, manipulation of the feeding schedule

  5. Comparison of piracetam measured with HPLC-DAD, HPLC-ESI-MS, DIP-APCI-MS, and a newly developed and optimized DIP-ESI-MS.

    PubMed

    Lenzen, Claudia; Winterfeld, Gottfried A; Schmitz, Oliver J

    2016-06-01

    The direct inlet probe-electrospray ionization (DIP-ESI) presented here was based on the direct inlet probe-atmospheric pressure chemical ionization (DIP-APCI) developed by our group. It was coupled to an ion trap mass spectrometer (MS) for the detection of more polar compounds such as degradation products from pharmaceuticals. First, the position of the ESI tip, the gas and solvent flow rates, as well as the gas temperature were optimized with the help of the statistic program Minitab® 17 and a caffeine standard. The ability to perform quantitative analyses was also tested by using different concentrations of caffeine and camphor. Calibration curves with a quadratic calibration regression of R (2) = 0.9997 and 0.9998 for caffeine and camphor, respectively, were obtained. The limit of detection of 2.5 and 1.7 ng per injection for caffeine and camphor were determined, respectively. Furthermore, a solution of piracetam was used to compare established analytical methods for this drug and its impurities such as HPLC-diode array detector (DAD) and HPLC-ESI-MS with the DIP-APCI and the developed DIP-ESI. With HPLC-DAD and 10 μg piracetam on column, no impurity could be detected. With HPLC-ESI-MS, two impurities (A and B) were identified with only 4.6 μg piracetam on column, while with DIP-ESI, an amount of 1.6 μg piracetam was sufficient. In the case of the DIP-ESI measurements, all detected impurities could be identified by MS/MS studies. Graphical Abstract Scheme of the DIP-ESI principle.

  6. Wavelet-based peak detection and a new charge inference procedure for MS/MS implemented in ProteoWizard's msConvert.

    PubMed

    French, William R; Zimmerman, Lisa J; Schilling, Birgit; Gibson, Bradford W; Miller, Christine A; Townsend, R Reid; Sherrod, Stacy D; Goodwin, Cody R; McLean, John A; Tabb, David L

    2015-02-06

    We report the implementation of high-quality signal processing algorithms into ProteoWizard, an efficient, open-source software package designed for analyzing proteomics tandem mass spectrometry data. Specifically, a new wavelet-based peak-picker (CantWaiT) and a precursor charge determination algorithm (Turbocharger) have been implemented. These additions into ProteoWizard provide universal tools that are independent of vendor platform for tandem mass spectrometry analyses and have particular utility for intralaboratory studies requiring the advantages of different platforms convergent on a particular workflow or for interlaboratory investigations spanning multiple platforms. We compared results from these tools to those obtained using vendor and commercial software, finding that in all cases our algorithms resulted in a comparable number of identified peptides for simple and complex samples measured on Waters, Agilent, and AB SCIEX quadrupole time-of-flight and Thermo Q-Exactive mass spectrometers. The mass accuracy of matched precursor ions also compared favorably with vendor and commercial tools. Additionally, typical analysis runtimes (∼1-100 ms per MS/MS spectrum) were short enough to enable the practical use of these high-quality signal processing tools for large clinical and research data sets.

  7. Customizing Process to Align with Purpose and Program: The 2003 MS PHD'S in Ocean Sciences Program Evaluative Case Study

    NASA Astrophysics Data System (ADS)

    Williamson, V. A.; Pyrtle, A. J.

    2004-12-01

    How did the 2003 Minorities Striving and Pursuing Higher Degrees of Success (MS PHD'S) in Ocean Sciences Program customize evaluative methodology and instruments to align with program goals and processes? How is data captured to document cognitive and affective impact? How are words and numbers utilized to accurately illustrate programmatic outcomes? How is compliance with implicit and explicit funding regulations demonstrated? The 2003 MS PHD'S in Ocean Sciences Program case study provides insightful responses to each of these questions. MS PHD'S was developed by and for underrepresented minorities to facilitate increased and sustained participation in Earth system science. Key components of this initiative include development of a community of scholars sustained by face-to-face and virtual mentoring partnerships; establishment of networking activities between and among undergraduate, graduate, postgraduate students, scientists, faculty, professional organization representatives, and federal program officers; and provision of forums to address real world issues as identified by each constituent group. The evaluative case study of the 2003 MS PHD'S in Ocean Sciences Program consists of an analysis of four data sets. Each data set was aligned to document progress in the achievement of the following program goals: Goal 1: The MS PHD'S Ocean Sciences Program will successfully market, recruit, select, and engage underrepresented student and non-student participants with interest/ involvement in Ocean Sciences; Goal 2: The MS PHD'S Ocean Sciences Program will provide meaningful engagement for participants as determined by quantitative analysis of user-feedback; Goal 3: The MS PHD'S Ocean Sciences Program will provide meaningful engagement for participants as determined by qualitative analysis of user-feedback, and; Goal 4: The MS PHD'S Ocean Sciences Program will develop a constituent base adequate to demonstrate evidence of interest, value, need and sustainability in

  8. Assessment of salivary free cortisol levels by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in patients treated with mitotane.

    PubMed

    Carrozza, Cinzia; Lapolla, Rosa; Gervasoni, Jacopo; Rota, Carlo Antonio; Locantore, Pietro; Pontecorvi, Alfredo; Zuppi, Cecilia; Persichilli, Silvia

    2012-01-01

    Mitotane is an adrenocytolytic agent used in adrenocortical carcinoma, inducing adrenal insufficiency, requiring replacement treatment. Such therapy is not easy to monitor because of mitotane interference. Salivary cortisol reflects a free fraction of plasma cortisol and may be useful in such patients. The aim of our study was to evaluate salivary cortisol by HPLC coupled to tandem-mass spectrometry (LC-MS/MS) and by an electrochemiluminescence immunoassay (ECLIA) in patients treated with mitotane. We enrolled 6 patients receiving mitotane and 2 Addison disease patients as negative controls and determined salivary cortisol rhythm. We also determined the salivary cortisol rhythm in 8 healthy subjects. Salivary samples (n=112) were assayed by ECLIA, using Roche Modular E170, and by LC-MS/MS. The mean values obtained by ECLIA were significantly higher than those obtained by LC-MS/MS in the mitotane group (p<0.001). In fact, in the group measured by LC-MS/MS, we observed several peaks eluting at a retention time different from the cortisol group, presumably due to cortisol-like analogues. In Addison disease, since steroidogenesis is absent, salivary cortisol values measured by the two methods did not show any significant difference (p=0.61). Salivary cortisol measured by LC-MS/MS is a selective method, excluding cortisol analogues accumulating in treated patients. Therefore, LC-MS/MS offers an effective system to monitor replacement therapy in mitotane treated patients.

  9. Structural Studies of MS2 Bacteriophage Virus Particle Disassembly by Nuclear Magnetic Resonance Relaxation Measurements

    PubMed Central

    Anobom, C. D.; Albuquerque, S. C.; Albernaz, F. P.; Oliveira, A. C.; Silva, J. L.; Peabody, D. S.; Valente, A. P.; Almeida, F. C. L.

    2003-01-01

    In this article we studied, by nuclear magnetic resonance relaxation measurements, the disassembly of a virus particle—the MS2 bacteriophage. MS2 is one of the single-stranded RNA bacteriophages that infect Escherichia coli. At pH 4.5, the phage turns to a metastable state, as is indicated by an increase in the observed nuclear magnetic resonance signal intensity upon decreasing the pH from 7.0 to 4.5. Steady-state fluorescence and circular dichroism spectra at pH 4.5 show that the difference in conformation and secondary structure is not pronounced if compared with the phage at pH 7.0. At pH 4.5, two-dimensional 15N-1H heteronuclear multiple quantum coherence (HMQC) spectrum shows ∼40 crosspeaks, corresponding to the most mobile residues of MS2 coat protein at pH 4.5. The 15N linewidth is ∼30 Hz, which is consistent with an intermediate with a rotational relaxation time of 100 ns. The average spin lattice relaxation time (T1) of the mobile residues was measured at different temperatures, clearly distinguishing between the dimer and the equilibrium intermediate. The results show, for the first time, the presence of intermediates in the process of dissociation of the MS2 bacteriophage. PMID:12770895

  10. Enantioselective Determination of Polycyclic Musks in River and Wastewater by GC/MS/MS

    PubMed Central

    Lee, Injung; Gopalan, Anantha-Iyengar; Lee, Kwang-Pill

    2016-01-01

    The separation of chiral compounds is an interesting and challenging topic in analytical chemistry, especially in environmental fields. Enantioselective degradation or bioaccumulation has been observed for several chiral pollutants. Polycyclic musks are chiral and are widely used as fragrances in a variety of personal care products such as soaps, shampoos, cosmetics and perfumes. In this study, the gas chromatographic separation of chiral polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclo-penta-γ-2-benzopyrane (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetra-hydronaphthalene (AHTN), 6-acetyl-1,1,2,3,3,5-hexamethylindane (AHDI), 5-acetyl-1,1,2,6-tetramethyl-3-iso-propylindane (ATII), and 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone (DPMI) was achieved on modified cyclodextrin stationary phase (heptakis (2,3-di-O-methyl-6-O-tert-butyl-dimethylsilyl-β-CD in DV-1701)). Separation techniques are coupled to tandem mass spectrometry (MS-MS), as it provides the sensitivity and selectivity needed. River and wastewaters (influents and effluents of wastewater treatment plants (WWTPs)) in the Nakdong River were investigated with regard to the concentrations and the enantiomeric ratios of polycyclic musks. HHCB was most frequently detected in river and wastewaters, and an enantiomeric enrichment was observed in the effluents of one of the investigated wastewater treatment plants (WWTPs). We reported the contamination of river and wastewaters in Korea by chiral polycyclic musks. The results of this investigation suggest that enantioselective transformation may occur during wastewater treatment. PMID:27011195

  11. MsLDR-creator: a web service to design msLDR assays.

    PubMed

    Bormann, Felix; Dahl, Andreas; Sers, Christine

    2012-03-01

    MsLDR-creator is a free web service to design assays for the new DNA methylation detection method msLDR. The service provides the user with all necessary information about the oligonucleotides required for the measurement of a given CpG within a sequence of interest. The parameters are calculated by the nearest neighbour approach to achieve optimal behaviour during the experimental procedure. In addition, to guarantee a good start using msLDR, further information, like protocols and hints and tricks, are provided.

  12. ICP-MS/MS-Based Ionomics: A Validated Methodology to Investigate the Biological Variability of the Human Ionome.

    PubMed

    Konz, Tobias; Migliavacca, Eugenia; Dayon, Loïc; Bowman, Gene; Oikonomidi, Aikaterini; Popp, Julius; Rezzi, Serge

    2017-05-05

    We here describe the development, validation and application of a quantitative methodology for the simultaneous determination of 29 elements in human serum using state-of-the-art inductively coupled plasma triple quadrupole mass spectrometry (ICP-MS/MS). This new methodology offers high-throughput elemental profiling using simple dilution of minimal quantity of serum samples. We report the outcomes of the validation procedure including limits of detection/quantification, linearity of calibration curves, precision, recovery and measurement uncertainty. ICP-MS/MS-based ionomics was used to analyze human serum of 120 older adults. Following a metabolomic data mining approach, the generated ionome profiles were subjected to principal component analysis revealing gender and age-specific differences. The ionome of female individuals was marked by higher levels of calcium, phosphorus, copper and copper to zinc ratio, while iron concentration was lower with respect to male subjects. Age was associated with lower concentrations of zinc. These findings were complemented with additional readouts to interpret micronutrient status including ceruloplasmin, ferritin and inorganic phosphate. Our data supports a gender-specific compartmentalization of the ionome that may reflect different bone remodelling in female individuals. Our ICP-MS/MS methodology enriches the panel of validated "Omics" approaches to study molecular relationships between the exposome and the ionome in relation with nutrition and health.

  13. Brain volume in early MS patients with and without IgG oligoclonal bands in CSF.

    PubMed

    Fenu, G; Lorefice, L; Sechi, V; Loi, L; Contu, F; Cabras, F; Coghe, G; Frau, J; Secci, M A; Melis, C; Schirru, L; Costa, G; Melas, V; Arru, M; Barracciu, M A; Marrosu, M G; Cocco, E

    2018-01-01

    Oligoclonal bands of IgG (OB) are proposed as an early prognostic factor of the disease. Growing attention is directed towards brain volume evaluation as a possible marker of the severity of MS. Previous studies found that MS patients lacking OB have less brain atrophy. to evaluate a possible relationship between OB and cerebral volume in a cohort of early MS patients. Inclusion criteria were: diagnosis of relapsing-remitting MS; CSF analysis and MRI acquired simultaneously and within 12 months from clinical onset. A total of 15 healthy controls underwent MRI. In 20 MS patients, CSF analysis did not show OB synthesis (OB negative group). A control group of 25 MS patients in whom OB was detected was also randomly recruited (OB positive group). T test showed a significant difference in NWV between the OB positive and OB negative groups (P value = 0.01), and between the OB positive group and the healthy controls (P value = 0.001). No differences were detected between OB negative group and healthy controls. Multivariable linear regression showed a relationship between NWV and OB synthesis (P value = 0.02) controlling for age, gender, and EDSS. Our preliminary results suggest that OB positive patients show more atrophy of white matter since early phases of the disease, supporting the role of CSF analysis as a prognostic factor in MS. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Validated method to measure yakuchinone A in plasma by LC-MS/MS and its application to a pharmacokinetic study in rats

    PubMed Central

    2014-01-01

    Background Yakuchinone A has a plethora of beneficial biological effects. However, the pharmacokinetic (PK) data of yakuchinone A still remain unknown so far. Furthermore, the quantification of yakuchinone A in biological samples has not been reported in the literature. Therefore, in the present study we aimed to develop a new method for the fast, efficient and accurate assessment of yakuchinone A concentration in plasma, as a means for facilitating the PK evaluation of yakuchinone A. Results A liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed and validated for the determination of yakuchinone A in rat plasma. Mass spectrometric and chromatographic conditions were optimized. Plasma samples were pretreated by protein precipitation with methanol. LC separation was performed on a Phenomenex Luna C18 column with gradient elution using a mobile phase consisting of methanol–water containing 0.5 mM formic acid (HCOOH) at a flow rate of 0.28 mL/min. ESI-MS spectra were acquired in positive ion multiple reaction monitoring mode (MRM). The precursor-to-product ion pairs used for MRM of yakuchinone A and yakuchinone B were m/z 313.1 → 137.0 and 311.2 → 117.1, respectively. Low concentration of HCOOH reduced the ion suppression caused by matrix components and clearly improved the analytical sensitivity. Yakuchinone A showed good linearity over a wide concentration range (r > 0.99). The accuracy, precision, stability and linearity were found to be within the acceptable criteria. This new method was successfully applied to analyze the rat plasma concentration of parent yakuchinone A after a single oral administration of SuoQuan capsules. Low systemic exposure to parent yakuchinone A was observed. Conclusion The proposed method is sensitive and reliable. It is hoped that this new method will prove useful for the future PK studies. PMID:24422995

  15. Tempest: Accelerated MS/MS database search software for heterogeneous computing platforms

    PubMed Central

    Adamo, Mark E.; Gerber, Scott A.

    2017-01-01

    MS/MS database search algorithms derive a set of candidate peptide sequences from in-silico digest of a protein sequence database, and compute theoretical fragmentation patterns to match these candidates against observed MS/MS spectra. The original Tempest publication described these operations mapped to a CPU-GPU model, in which the CPU generates peptide candidates that are asynchronously sent to a discrete GPU to be scored against experimental spectra in parallel (Milloy et al., 2012). The current version of Tempest expands this model, incorporating OpenCL to offer seamless parallelization across multicore CPUs, GPUs, integrated graphics chips, and general-purpose coprocessors. Three protocols describe how to configure and run a Tempest search, including discussion of how to leverage Tempest's unique feature set to produce optimal results. PMID:27603022

  16. Competence-Based System Self-Study System for Suggesting Study Materials Links

    ERIC Educational Resources Information Center

    Nitchot, Athitaya; Gilbert, Lester; Wills, Gary B.

    2014-01-01

    The article proposes a self-study system which suggests web links to learners. The suggestions depend upon the learner's chosen competences selected from a competence structure for a particular knowledge domain. Three experiments were conducted, where the first compared the perceived usefulness and value of the links generated by different…

  17. Development and validation of a UPLC-MS/MS method for simultaneous determination of fotagliptin and its two major metabolites in human plasma and urine.

    PubMed

    Wang, Zhenlei; Jiang, Ji; Hu, Pei; Zhao, Qian

    2017-02-01

    Fotagliptin is a novel dipeptidyl peptidase IV inhibitor under clinical development for the treatment of Type II diabetes mellitus. The objective of this study was to develop and validate a specific and sensitive ultra-performance liquid chromatography (UPLC)-MS/MS method for simultaneous determination of fotagliptin and its two major metabolites in human plasma and urine. Methodology & results: After being pretreated using an automatized procedure, the plasma and urine samples were separated and detected using a UPLC-ESI-MS/MS method, which was validated following the international guidelines. A selective and sensitive UPLC-MS/MS method was first developed and validated for quantifying fotagliptin and its metabolite in human plasma and urine. The method was successfully applied to support the clinical study of fotagliptin in Chinese healthy subjects.

  18. Identification and characterization of stress degradants of lacosamide by LC-MS and ESI-Q-TOF-MS/MS: development and validation of a stability indicating RP-HPLC method.

    PubMed

    Ramisetti, Nageswara Rao; Kuntamukkala, Ramakrishna; Lakshetti, Sridhar; Sripadi, Prabhakar

    2014-07-01

    The current study dealt with the degradation behavior of lacosamide (LAC) under ICH prescribed stress conditions. LAC was found to be labile under acid and base hydrolytic stress conditions, while it was stable to neutral hydrolytic, oxidative, photolytic and thermal stress. In total, seven degradation products (DPs) were formed, which were separated on a C18 column using a stability-indicating method. LC-MS analyses indicated that one of the DPs had the same molecular mass as that of the drug. Structural characterization of DPs was carried out using ESI-Q-TOF-MS/MS technique. The degradation pathways and mechanisms of degradation of the drug were delineated by carrying out the degradation in different co-solvents viz. methanol, deuterated methanol, ethanol, 1-propanol and acetonitrile. The developed LC method was validated for the determination of related substances and assay of LAC as per ICH guidelines. This study demonstrates a comprehensive approach of LAC degradation studies during its development phase. Copyright © 2014. Published by Elsevier B.V.

  19. Development of a multi-matrix LC-MS/MS method for urea quantitation and its application in human respiratory disease studies.

    PubMed

    Wang, Jianshuang; Gao, Yang; Dorshorst, Drew W; Cai, Fang; Bremer, Meire; Milanowski, Dennis; Staton, Tracy L; Cape, Stephanie S; Dean, Brian; Ding, Xiao

    2017-01-30

    In human respiratory disease studies, liquid samples such as nasal secretion (NS), lung epithelial lining fluid (ELF), or upper airway mucosal lining fluid (MLF) are frequently collected, but their volumes often remain unknown. The lack of volume information makes it hard to estimate the actual concentration of recovered active pharmaceutical ingredient or biomarkers. Urea has been proposed to serve as a sample volume marker because it can freely diffuse through most body compartments and is less affected by disease states. Here, we report an easy and reliable LC-MS/MS method for cross-matrix measurement of urea in serum, plasma, universal transfer medium (UTM), synthetic absorptive matrix elution buffer 1 (SAMe1) and synthetic absorptive matrix elution buffer 2 (SAMe2) which are commonly sampled in human respiratory disease studies. The method uses two stable-isotope-labeled urea isotopologues, [ 15 N 2 ]-urea and [ 13 C, 15 N 2 ]-urea, as the surrogate analyte and the internal standard, respectively. This approach provides the best measurement consistency across different matrices. The analyte extraction was individually optimized in each matrix. Specifically in UTM, SAMe1 and SAMe2, the unique salting-out assisted liquid-liquid extraction (SALLE) not only dramatically reduces the matrix interferences but also improves the assay recovery. The use of an HILIC column largely increases the analyte retention. The typical run time is 3.6min which allows for high throughput analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. MS Sunshine Study: Sun Exposure But Not Vitamin D Is Associated with Multiple Sclerosis Risk in Blacks and Hispanics.

    PubMed

    Langer-Gould, Annette; Lucas, Robyn; Xiang, Anny H; Chen, Lie H; Wu, Jun; Gonzalez, Edlin; Haraszti, Samantha; Smith, Jessica B; Quach, Hong; Barcellos, Lisa F

    2018-02-27

    Multiple sclerosis (MS) incidence and serum 25-hydroxyvitamin D (25OHD) levels vary by race/ethnicity. We examined the consistency of beneficial effects of 25OHD and/or sun exposure for MS risk across multiple racial/ethnic groups. We recruited incident MS cases and controls (blacks 116 cases/131 controls; Hispanics 183/197; whites 247/267) from the membership of Kaiser Permanente Southern California into the MS Sunshine Study to simultaneously examine sun exposure and 25OHD, accounting for genetic ancestry and other factors. Higher lifetime ultraviolet radiation exposure (a rigorous measure of sun exposure) was associated with a lower risk of MS independent of serum 25OHD levels in blacks (adjusted OR = 0.53, 95% CI = 0.31-0.83; p = 0.007) and whites (OR = 0.68, 95% CI = 0.48-0.94; p = 0.020) with a similar magnitude of effect that did not reach statistical significance in Hispanics (OR = 0.66, 95% CI = 0.42-1.04; p = 0.071). Higher serum 25OHD levels were associated with a lower risk of MS only in whites. No association was found in Hispanics or blacks regardless of how 25OHD was modeled. Lifetime sun exposure appears to reduce the risk of MS regardless of race/ethnicity. In contrast, serum 25OHD levels are not associated with MS risk in blacks or Hispanics. Our findings challenge the biological plausibility of vitamin D deficiency as causal for MS and call into question the targeting of specific serum 25OHD levels to achieve health benefits, particularly in blacks and Hispanics.

  1. Study of flavour compounds from orange juices by HS-SPME and GC-MS

    NASA Astrophysics Data System (ADS)

    Schmutzer, G.; Avram, V.; Covaciu, F.; Feher, I.; Magdas, A.; David, L.; Moldovan, Z.

    2013-11-01

    The flavour of the orange juices, which gives the taste and odour of the product, is an important criterion about the products quality for consumers. A fresh single strength and two commercial orange juices (obtained from concentrate) flavour profile were studied using a selective and sensitive gas chromatography - mass spectrometry (GC-MS) analytical system, after a solvent free, single step preconcentration and extraction technique, the headspace solid phase microextraction (HP-SPME). In the studied orange juices 55 flavour compounds were detected and classified as belonging to the esters, alcohols, ketones, monoterpenes and sesquiterpenes chemical families. The fresh single strength orange juice was characterized by high amount of esters, monoterpenes and sesquiterpenes. Limonene and valencene were the most abundant flavours in this fresh natural orange juice. Alcohols and ketones were found in higher concentration in the commercial orange juices made from concentrate, than in the single strength products. Nevertheless, in commercial juices the most abundant flavour was limonene and α-terpineol. The results highlight clear differences between fresh singles strength orange juice and juice from concentrate. The orange juices reconstructed from concentrate, made in Romania, present low quantity of flavour compounds, suggesting the absence or a low rearomatization process, but extraneous components were not detected.

  2. A comparison between DART-MS and DSA-MS in the forensic analysis of writing inks.

    PubMed

    Drury, Nicholas; Ramotowski, Robert; Moini, Mehdi

    2018-05-23

    Ambient ionization mass spectrometry is gaining momentum in forensic science laboratories because of its high speed of analysis, minimal sample preparation, and information-rich results. One such application of ambient ionization methodology includes the analysis of writing inks from questioned documents where colorants of interest may not be soluble in common solvents, rendering thin layer chromatography (TLC) and separation-mass spectrometry methods such as LC/MS (-MS) impractical. Ambient ionization mass spectrometry uses a variety of ionization techniques such as penning ionization in Direct Analysis in Real Time (DART), and atmospheric pressure chemical ionization in Direct Sample Analysis (DSA), and electrospray ionization in Desorption Electrospray Ionization (DESI). In this manuscript, two of the commonly used ambient ionization techniques are compared: Perkin Elmer DSA-MS and IonSense DART in conjunction with a JEOL AccuTOF MS. Both technologies were equally successful in analyzing writing inks and produced similar spectra. DSA-MS produced less background signal likely because of its closed source configuration; however, the open source configuration of DART-MS provided more flexibility for sample positioning for optimum sensitivity and thereby allowing smaller piece of paper containing writing ink to be analyzed. Under these conditions, the minimum sample required for DART-MS was 1mm strokes of ink on paper, whereas DSA-MS required a minimum of 3mm. Moreover, both techniques showed comparable repeatability. Evaluation of the analytical figures of merit, including sensitivity, linear dynamic range, and repeatability, for DSA-MS and DART-MS analysis is provided. To the forensic context of the technique, DART-MS was applied to the analysis of United States Secret Service ink samples directly on a sampling mesh, and the results were compared with DSA-MS of the same inks on paper. Unlike analysis using separation mass spectrometry, which requires sample

  3. Natural isotope correction of MS/MS measurements for metabolomics and (13)C fluxomics.

    PubMed

    Niedenführ, Sebastian; ten Pierick, Angela; van Dam, Patricia T N; Suarez-Mendez, Camilo A; Nöh, Katharina; Wahl, S Aljoscha

    2016-05-01

    Fluxomics and metabolomics are crucial tools for metabolic engineering and biomedical analysis to determine the in vivo cellular state. Especially, the application of (13)C isotopes allows comprehensive insights into the functional operation of cellular metabolism. Compared to single MS, tandem mass spectrometry (MS/MS) provides more detailed and accurate measurements of the metabolite enrichment patterns (tandem mass isotopomers), increasing the accuracy of metabolite concentration measurements and metabolic flux estimation. MS-type data from isotope labeling experiments is biased by naturally occurring stable isotopes (C, H, N, O, etc.). In particular, GC-MS(/MS) requires derivatization for the usually non-volatile intracellular metabolites introducing additional natural isotopes leading to measurements that do not directly represent the carbon labeling distribution. To make full use of LC- and GC-MS/MS mass isotopomer measurements, the influence of natural isotopes has to be eliminated (corrected). Our correction approach is analyzed for the two most common applications; (13)C fluxomics and isotope dilution mass spectrometry (IDMS) based metabolomics. Natural isotopes can have an impact on the calculated flux distribution which strongly depends on the substrate labeling and the actual flux distribution. Second, we show that in IDMS based metabolomics natural isotopes lead to underestimated concentrations that can and should be corrected with a nonlinear calibration. Our simulations indicate that the correction for natural abundance in isotope based fluxomics and quantitative metabolomics is essential for correct data interpretation. © 2015 Wiley Periodicals, Inc.

  4. LC-MS/MS methods for the determination of edaravone and/or taurine in rat plasma and its application to a pharmacokinetic study.

    PubMed

    Tang, Dao-quan; Bian, Ting-ting; Zheng, Xiao-xiao; Li, Ying; Wu, Xiao-wen; Li, Yin-jie; Du, Qian; Jiang, Shui-shi

    2014-09-01

    Three liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were respectively developed and validated for the simultaneous or independent determination of taurine and edaravone in rat plasma using 3-methyl-1-p-tolyl-5-pyrazolone and sulfanilic acid as the internal standards (IS). Chromatographic separations were achieved on an Agilent Zorbax SB-Aq (100 × 2.1 mm, 3.5 µm) column. Gradient 0.03% formic acid-methanol, isocratic 0.1% formic acid-methanol (90:10) and 0.02% formic acid-methanol (40:60) were respectively selected as the mobile phase for the simultaneous determination of two analytes, taurine or edaravone alone. The MS acquisition was performed in multiple reaction monitoring mode with a positive and negative electrospray ionization source. The mass transitions monitored were m/z [M + H](+) 175.1 → 133.0 and [M + H](+) 189.2 → 147.0 for edaravone and its IS, m/z [M - H](-) 124.1 → 80.0 and [M - H](-) 172.0 → 80.0 for taurine and its IS, respectively. The validated methods were successfully applied to study the pharmacokinetic interaction of taurine and edaravone in rats after independent intravenous administration and co-administration with a single dose. Our collective results showed that there were no significant alterations on the main pharmacokinetic parameters (area under concentration-time curve, mean residence time, half-life and clearance) of taurine and edaravone, implying that the proposed combination therapy was pharmacologically feasible. Copyright © 2014 John Wiley & Sons, Ltd.

  5. THC:CBD Observational Study Data: Evolution of Resistant MS Spasticity and Associated Symptoms.

    PubMed

    Trojano, Maria

    2016-01-01

    The prospective observational MObility ImproVEment (MOVE) 2 study is collecting real-life clinical outcomes data on patients with treatment-resistant multiple sclerosis (MS) spasticity treated with THC:CBD oromucosal spray in routine clinical practice. The MOVE 2 study has been ongoing in Italy, involving more than 30 MS centres across the country, since 2013. Web-based real-time data collection techniques are combined with traditional patients' diaries to capture a wide spectrum of outcomes associated with this innovative cannabis-based medication. After surpassing the recruitment threshold of 300 patients, an interim analysis was performed to determine whether the data collected to date align with those from MOVE 2-Germany and the largest phase III randomized controlled trial (RCT) of THC:CBD oromucosal spray. In the Italian cohort, THC:CBD oromucosal spray was added mainly to oral baclofen. Similar to MOVE 2-Germany, during 3 months' observation, treatment discontinuations were limited and patients recorded meaningful improvements on the patient-based 0-10 numerical rating scale and physician-rated modified Ashworth scale at mean daily doses that were about one-third lower than those used in the RCT. Also, similar to MOVE 2-Germany, the proportion of patients reporting adverse events was about one-third of the rate recorded in the RCT. While MOVE 2-Italy continues, this interim analysis has enabled us to better define the place in therapy of THC:CBD oromucosal spray within the context of daily management of our patients with MS spasticity. © 2016 S. Karger AG, Basel.

  6. THC:CBD spray and MS spasticity symptoms: data from latest studies.

    PubMed

    Rekand, Tiina

    2014-01-01

    New clinical experience with 9-delta-tetrahydocannabinol (THC) and cannabidiol (CBD) oromucosal spray (Sativex®) involving more than an additional 1,000 patients with MS spasticity (approximately 150 in clinical studies and 900 in post-marketing surveillance studies) have become available in 2013 and are reviewed. A randomized, placebo controlled long-term follow-up clinical trial with THC:CBD spray versus placebo demonstrated that it was not associated with cognitive decline, depression or significant mood changes after 12 months of treatment. Furthermore, in a prospective observational pilot study involving 33 patients (60% female) aged 33-68 years and a mean disease duration of 6.6 years, THC:CBD oromucosal spray did not adversely influence standard driving ability in patients with moderate to severe MS spasticity. Other new long term observational data about the use of THC:CBD oromucosal spray in clinical practice are available from patient registries in the UK, Germany and Spain. Findings to date reinforce the efficacy and safety observed in Phase III clinical trials. It is of interest that in practice average dosages used by patients tended to be lower than those reported in clinical studies (5-6.4 vs. >8 sprays/day), and effectiveness was maintained in the majority of patients. Importantly, no additional safety concerns were identified in the registry studies which included findings from patients who have been treated for prolonged periods (in the German/UK registry 45% of patients had >2 years exposure). Thus, these new data support a positive benefit-risk relationship for THC:CBD oromucosal spray during longer-term use. © 2014 S. Karger AG, Basel.

  7. [Study on supercritical CO2 extraction of xiaoyaosan and its GC-MS fingerprint].

    PubMed

    Zuo, Ya-Mei; Tian, Jun-Sheng; Guo, Xiao-Qing; Zhou, Yu-Zhi; Gao, Xiao-Xia; Qin, Xue-Mei

    2014-02-01

    To determine the optimum conditions of supercritical CO2 extraction of Xiaoyaosan, and establish its fingerprint by gas chromatography-mass spectrometry (GC-MS), the yield of extract were investigated, an orthogonal test was used to quantify the effects of extraction temperature, pressure, CO2 flow rate and time, and fingerprint analysis of different batches of extracts were by GC-MS. The optimal extraction conditions were determined as follows: extraction pressure 20 MPa, extraction temperature 50 degrees C, CO2 flow rate 25 kg x h(-1), extraction time 3 h, and average yield 2.2%. The GC-MS fingerprint was established and 27 common peaks were found, whose contents add up to 81.89% of the total peak area. Among them, 21 compounds were identified, accounting for 53.20% of the total extract. The extraction process is reasonable and favorable for industrial production. The GC-MS method is accurate, reliable, reproducible, and can be used for quality control of supercritical CO2 extract from Xiaoyaosan.

  8. MS/MS-Assisted Design of Sequence-Controlled Synthetic Polymers for Improved Reading of Encoded Information

    NASA Astrophysics Data System (ADS)

    Charles, Laurence; Cavallo, Gianni; Monnier, Valérie; Oswald, Laurence; Szweda, Roza; Lutz, Jean-François

    2017-06-01

    In order to improve their MS/MS sequencing, structure of sequence-controlled synthetic polymers can be optimized based on considerations regarding their fragmentation behavior in collision-induced dissociation conditions, as demonstrated here for two digitally encoded polymer families. In poly(triazole amide)s, the main dissociation route proceeded via cleavage of the amide bond in each monomer, hence allowing the chains to be safely sequenced. However, a competitive cleavage of an ether bond in a tri(ethylene glycol) spacer placed between each coding moiety complicated MS/MS spectra while not bringing new structural information. Changing the tri(ethylene glycol) spacer to an alkyl group of the same size allowed this unwanted fragmentation pathway to be avoided, hence greatly simplifying the MS/MS reading step for such undecyl-based poly(triazole amide)s. In poly(alkoxyamine phosphodiester)s, a single dissociation pathway was achieved with repeating units containing an alkoxyamine linkage, which, by very low dissociation energy, made any other chemical bonds MS/MS-silent. Structure of these polymers was further tailored to enhance the stability of those precursor ions with a negatively charged phosphate group per monomer in order to improve their MS/MS readability. Increasing the size of both the alkyl coding moiety and the nitroxide spacer allowed sufficient distance between phosphate groups for all of them to be deprotonated simultaneously. Because the charge state of product ions increased with their polymerization degree, MS/MS spectra typically exhibited groups of fragments at one or the other side of the precursor ion depending on the original α or ω end-group they contain, allowing sequence reconstruction in a straightforward manner. [Figure not available: see fulltext.

  9. Structure Annotation and Quantification of Wheat Seed Oxidized Lipids by High-Resolution LC-MS/MS.

    PubMed

    Riewe, David; Wiebach, Janine; Altmann, Thomas

    2017-10-01

    Lipid oxidation is a process ubiquitous in life, but the direct and comprehensive analysis of oxidized lipids has been limited by available analytical methods. We applied high-resolution liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (MS/MS) to quantify oxidized lipids (glycerides, fatty acids, phospholipids, lysophospholipids, and galactolipids) and implemented a platform-independent high-throughput-amenable analysis pipeline for the high-confidence annotation and acyl composition analysis of oxidized lipids. Lipid contents of 90 different naturally aged wheat ( Triticum aestivum ) seed stocks were quantified in an untargeted high-resolution LC-MS experiment, resulting in 18,556 quantitative mass-to-charge ratio features. In a posthoc liquid chromatography-tandem mass spectrometry experiment, high-resolution MS/MS spectra (5 mD accuracy) were recorded for 8,957 out of 12,080 putatively monoisotopic features of the LC-MS data set. A total of 353 nonoxidized and 559 oxidized lipids with up to four additional oxygen atoms were annotated based on the accurate mass recordings (1.5 ppm tolerance) of the LC-MS data set and filtering procedures. MS/MS spectra available for 828 of these annotations were analyzed by translating experimentally known fragmentation rules of lipids into the fragmentation of oxidized lipids. This led to the identification of 259 nonoxidized and 365 oxidized lipids by both accurate mass and MS/MS spectra and to the determination of acyl compositions for 221 nonoxidized and 295 oxidized lipids. Analysis of 15-year aged wheat seeds revealed increased lipid oxidation and hydrolysis in seeds stored in ambient versus cold conditions. © 2017 The author(s). All Rights Reserved.

  10. Profiling and characterization of sialylated N-glycans by 2D-HPLC (HIAX/PGC) with online orbitrap MS/MS and offline MSn.

    PubMed

    Hanneman, Andrew J S; Strand, James; Huang, Chi-Ting

    2014-02-01

    Glycosylation is a critical parameter used to evaluate protein quality and consistency. N-linked glycan profiling is fundamental to the support of biotherapeutic protein manufacturing from early stage process development through drug product commercialization. Sialylated glycans impact the serum half-life of receptor-Fc fusion proteins (RFPs), making their quality and consistency a concern during the production of fusion proteins. Here, we describe an analytical approach providing both quantitative profiling and in-depth mass spectrometry (MS)-based structural characterization of sialylated RFP N-glycans. Aiming to efficiently link routine comparability studies with detailed structural characterization, an integrated workflow was implemented employing fluorescence detection, online positive and negative ion tandem mass spectrometry (MS/MS), and offline static nanospray ionization-sequential mass spectrometry (NSI-MS(n)). For routine use, high-performance liquid chromatography profiling employs established fluorescence detection of 2-aminobenzoic acid derivatives (2AA) and hydrophilic interaction anion-exchange chromatography (HIAX) charge class separation. Further characterization of HIAX peak fractions is achieved by online (-) ion orbitrap MS/MS, offering the advantages of high mass accuracy and data-dependent MS/MS. As required, additional characterization uses porous graphitized carbon in the second chromatographic dimension to provide orthogonal (+) ion MS/MS spectra and buffer-free liquid chromatography peak eluants that are optimum for offline (+)/(-) NSI-MS(n) investigations to characterize low-abundance species and specific moieties including O-acetylation and sulfation. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  11. Systematic assessment of survey scan and MS2-based abundance strategies for label-free quantitative proteomics using high-resolution MS data.

    PubMed

    Tu, Chengjian; Li, Jun; Sheng, Quanhu; Zhang, Ming; Qu, Jun

    2014-04-04

    Survey-scan-based label-free method have shown no compelling benefit over fragment ion (MS2)-based approaches when low-resolution mass spectrometry (MS) was used, the growing prevalence of high-resolution analyzers may have changed the game. This necessitates an updated, comparative investigation of these approaches for data acquired by high-resolution MS. Here, we compared survey scan-based (ion current, IC) and MS2-based abundance features including spectral-count (SpC) and MS2 total-ion-current (MS2-TIC), for quantitative analysis using various high-resolution LC/MS data sets. Key discoveries include: (i) study with seven different biological data sets revealed only IC achieved high reproducibility for lower-abundance proteins; (ii) evaluation with 5-replicate analyses of a yeast sample showed IC provided much higher quantitative precision and lower missing data; (iii) IC, SpC, and MS2-TIC all showed good quantitative linearity (R(2) > 0.99) over a >1000-fold concentration range; (iv) both MS2-TIC and IC showed good linear response to various protein loading amounts but not SpC; (v) quantification using a well-characterized CPTAC data set showed that IC exhibited markedly higher quantitative accuracy, higher sensitivity, and lower false-positives/false-negatives than both SpC and MS2-TIC. Therefore, IC achieved an overall superior performance than the MS2-based strategies in terms of reproducibility, missing data, quantitative dynamic range, quantitative accuracy, and biomarker discovery.

  12. Systematic Assessment of Survey Scan and MS2-Based Abundance Strategies for Label-Free Quantitative Proteomics Using High-Resolution MS Data

    PubMed Central

    2015-01-01

    Survey-scan-based label-free method have shown no compelling benefit over fragment ion (MS2)-based approaches when low-resolution mass spectrometry (MS) was used, the growing prevalence of high-resolution analyzers may have changed the game. This necessitates an updated, comparative investigation of these approaches for data acquired by high-resolution MS. Here, we compared survey scan-based (ion current, IC) and MS2-based abundance features including spectral-count (SpC) and MS2 total-ion-current (MS2-TIC), for quantitative analysis using various high-resolution LC/MS data sets. Key discoveries include: (i) study with seven different biological data sets revealed only IC achieved high reproducibility for lower-abundance proteins; (ii) evaluation with 5-replicate analyses of a yeast sample showed IC provided much higher quantitative precision and lower missing data; (iii) IC, SpC, and MS2-TIC all showed good quantitative linearity (R2 > 0.99) over a >1000-fold concentration range; (iv) both MS2-TIC and IC showed good linear response to various protein loading amounts but not SpC; (v) quantification using a well-characterized CPTAC data set showed that IC exhibited markedly higher quantitative accuracy, higher sensitivity, and lower false-positives/false-negatives than both SpC and MS2-TIC. Therefore, IC achieved an overall superior performance than the MS2-based strategies in terms of reproducibility, missing data, quantitative dynamic range, quantitative accuracy, and biomarker discovery. PMID:24635752

  13. Development and Validation of a Novel LC-MS/MS Opioid Confirmation Assay: Evaluation of β-glucuronidase Enzymes and Sample Cleanup Methods.

    PubMed

    Yang, He S; Wu, Alan H B; Lynch, Kara L

    2016-06-01

    With the rise in the use and misuse of prescription opioids, there is an increasing need for the confirmed identification of opioid analgesics in toxicology laboratories. The goals of this study were to (i) systematically evaluate the hydrolysis efficiency of four β-glucuronidase enzymes under optimized condition; (ii) evaluate compound recovery, matrix effects and precision of three protein precipitation plates and (iii) develop and validate a qualitative liquid-chromatography mass spectrometry (LC-MS/MS) assay to identify 13 opioids in urine. A recombinant β-glucuronidase exhibited the best overall hydrolysis efficiency for seven opioid glucuronide conjugates compared with β-glucuronidase from red abalone, Escherichia coli and Patella vulgata One of the protein precipitation plates tested exhibited overall better recovery of the opioids and lower ion suppression compared with the other two plates. An ESI positive mode LC-MS/MS assay for qualitative opioid analysis was developed and validated. Linearity, LOD, precision, matrix effect, recovery, carryover and interference of the method were evaluated. Sixty-two patient samples were analyzed by both a legacy GC-MS opioid method and the LC-MS/MS method, and 22 samples were analyzed by the LC-MS/MS and an LC-MS/MS reference method. The results of the comparisons showed good concordance. Overall, we described an efficient sample preparation procedure for a sensitive qualitative opioid confirmation assay in urine. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Tempest: Accelerated MS/MS Database Search Software for Heterogeneous Computing Platforms.

    PubMed

    Adamo, Mark E; Gerber, Scott A

    2016-09-07

    MS/MS database search algorithms derive a set of candidate peptide sequences from in silico digest of a protein sequence database, and compute theoretical fragmentation patterns to match these candidates against observed MS/MS spectra. The original Tempest publication described these operations mapped to a CPU-GPU model, in which the CPU (central processing unit) generates peptide candidates that are asynchronously sent to a discrete GPU (graphics processing unit) to be scored against experimental spectra in parallel. The current version of Tempest expands this model, incorporating OpenCL to offer seamless parallelization across multicore CPUs, GPUs, integrated graphics chips, and general-purpose coprocessors. Three protocols describe how to configure and run a Tempest search, including discussion of how to leverage Tempest's unique feature set to produce optimal results. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  15. The MS Choices Survey: findings of a study assessing physician and patient perspectives on living with and managing multiple sclerosis

    PubMed Central

    Riñon, Alberto; Buch, Mandy; Holley, Derek; Verdun, Elisabetta

    2011-01-01

    Background Treatment of multiple sclerosis (MS) with disease-modifying drugs (DMDs) can reduce relapse frequency and delay disability progression. Although adherence to DMDs is difficult to measure accurately, evidence suggests that poor adherence is common and can compromise treatment success. There are likely to be multiple factors underlying poor adherence. To better understand these factors, the global MS Choices Survey investigated patient and physician perspectives regarding key aspects of MS diagnosis, treatment adherence and persistence, and disease management. Methods The survey was conducted in seven countries and involved patients with MS (age 18–60 years; MS diagnosis for ≥1 year; current treatment with a DMD) and physicians (neurologist for 3–30 years; treating ≥15 patients with MS per average month; >60% of time spent in clinical practice). Separate questionnaires were used for physicians and patients, each containing approximately 30 questions. Results Questionnaires were completed by 331 patients and 280 physicians. Several differences were observed between the responses of patients and physicians, particularly for questions relating to treatment adherence. Overall, the proportion of patients reporting taking a treatment break (31%) was almost twice that estimated by physicians (on average 17%). The reasons cited for poor adherence also differed between patients and physicians. For example, more physicians cited side effects as the main reason for poor patient adherence (82%), than responding patients (42%). Conclusions Physicians may underestimate the scale of poor adherence to DMDs, which could impact on their assessment of treatment efficacy and result in inappropriate treatment escalation. In addition, disparities were identified between patient and physician responses regarding the underlying reasons for poor adherence. Improvements in the dialog between patients and neurologists may increase adherence to DMDs. PMID:22259240

  16. Data-independent MS/MS quantification of neuropeptides for determination of putative feeding-related neurohormones in microdialysate.

    PubMed

    Schmerberg, Claire M; Liang, Zhidan; Li, Lingjun

    2015-01-21

    Food consumption is an important behavior that is regulated by an intricate array of neuropeptides (NPs). Although many feeding-related NPs have been identified in mammals, precise mechanisms are unclear and difficult to study in mammals, as current methods are not highly multiplexed and require extensive a priori knowledge about analytes. New advances in data-independent acquisition (DIA) MS/MS and the open-source quantification software Skyline have opened up the possibility to identify hundreds of compounds and quantify them from a single DIA MS/MS run. An untargeted DIA MS(E) quantification method using Skyline software for multiplexed, discovery-driven quantification was developed and found to produce linear calibration curves for peptides at physiologically relevant concentrations using a protein digest as internal standard. By using this method, preliminary relative quantification of the crab Cancer borealis neuropeptidome (<2 kDa, 137 peptides from 18 families) was possible in microdialysates from 8 replicate feeding experiments. Of these NPs, 55 were detected with an average mass error below 10 ppm. The time-resolved profiles of relative concentration changes for 6 are shown, and there is great potential for the use of this method in future experiments to aid in correlation of NP changes with behavior. This work presents an unbiased approach to winnowing candidate NPs related to a behavior of interest in a functionally relevant manner, and demonstrates the success of such a UPLC-MS(E) quantification method using the open source software Skyline.

  17. Metabolic profile of glyburide in human liver microsomes using LC-DAD-Q-TRAP-MS/MS.

    PubMed

    Ravindran, Selvan; Basu, Sudipta; Gorti, Santosh Kapil Kumar; Surve, Prashant; Sloka, Navya

    2013-05-01

    The sulfonylurea urea drug glyburide (glibenclamide) is widely used for the treatment of diabetes milletus and gestational diabetes. In previous studies monohydroxylated metabolites were identified and characterized for glyburide in different species, but the metabolite owing to the loss of cyclohexyl ring was identified only in mouse. Glyburide upon incubation with hepatic microsomes resulted in 10 metabolites for human. The current study identifies new metabolites of glyburide along with the hydroxylated metabolites that were reported earlier. The newly identified drug metabolites are dihydroxylated metabolites, a metabolite owing to the loss of cyclohexyl ring and one owing to hydroxylation with dehydrogenation. Among the 10 identified metabolites, there were six monohydroxylated metabolites, one dihydroxylated metabolite, two metabolites owing to hydroxylation and dehydrogenation, and one metabolite owing to the loss of cyclohexyl ring. New metabolites of glyburide were identified and characterized using liquid chromatography-diode array detector-quadruple-ion trap-mass spectrometry/mass spectrometry (LC-DAD-Q-TRAP-MS/MS). An enhanced mass scan-enhanced product ion scan with information-dependent acquisition mode in a Q-TRAP-MS/MS system was used to characterize the metabolites. Liquid chromatography with diode array detection was used as a complimentary technique to confirm and identify the metabolites. Metabolites formed in higher amounts were detected in both diode array detection and mass spectrometry detection. Copyright © 2012 John Wiley & Sons, Ltd.

  18. [Simultaneous determination of pesticide residues in agricultural products by LC-MS/MS].

    PubMed

    Watanabe, Minae; Ueno, Eiji; Inoue, Tomomi; Ohno, Haruka; Ikai, Yoshitomo; Morishita, Toshio; Oshima, Harumi; Hayashi, Rumiko

    2013-01-01

    A method for the simultaneous determination of multiple pesticide residues in agricultural products was developed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample was extracted with acetonitrile. Co-extractives were removed by GPC/graphitized carbon column SPE, and silica gel/PSA cartridge column SPE. Pesticides in the test solution were determined by LC-MS/MS using scheduled MRM. Recoveries of 124 pesticides from spinach, brown rice, soybean, orange and tomato were tested at the level of 0.1 µg/g, and those of 121 pesticides ranged from 70 to 120% (RSD≤15%). Pesticide residues in 239 agricultural products were investigated by this method, and residues of 49 pesticides were detected in 98 agricultural products.

  19. Changes to anti-JCV antibody levels in a Swedish national MS cohort.

    PubMed

    Warnke, Clemens; Ramanujam, Ryan; Plavina, Tatiana; Bergström, Tomas; Goelz, Susan; Subramanyam, Meena; Kockum, Ingrid; Rahbar, Afsar; Kieseier, Bernd C; Holmén, Carolina; Olsson, Tomas; Hillert, Jan; Fogdell-Hahn, Anna

    2013-11-01

    The anti-JC virus (JCV) antibody status has been introduced to stratify patients with multiple sclerosis (MS) for higher or lower risk of progressive multifocal leukoencephalopathy (PML). To assess the potential utility of anti-JCV antibody levels for earlier diagnosis or prediction of PML. An analytically validated antibody assay was used to determine serological status, normalised optical density values, and dilution titres for anti-JCV antibodies. The method was applied to stored sera of 1157 patients with MS including five cases of PML, all enrolled in the Swedish pharmacovigilance study for natalizumab (NAT). Anticytomegalovirus (CMV) and antivaricella-zoster (VZV) antibody levels served as controls. Prior to treatment with NAT, anti-JCV antibody levels were stable in the anti-JCV positive patients. During therapy, a slight decrease in anti-JCV and anti-VZV antibody levels, but not anti-CMV antibody levels, was observed. All five patients who developed PML showed a mild to moderate increase in anti-JCV antibody levels at time of PML diagnosis; pre-PML samples suggested that this increase might start already prior to diagnosis of PML. Treatment initiation with NAT may lead to a slight decrease in anti-JCV and anti-VZV antibody levels, suggestive of a mild suppressive effect of NAT on antibody levels. Our findings in five cases of PML demonstrate that the onset of PML can be accompanied by increasing anti-JCV antibodies in serum. Monitoring of anti-JCV antibody levels could potentially be used as a tool for prediction or earlier diagnosis of PML during NAT treatment for MS. Further studies are warranted.

  20. Reverse causality behind the association between reproductive history and MS.

    PubMed

    Hedström, A K; Hillert, J; Olsson, T; Alfredsson, L

    2014-04-01

    Possible associations between childbearing patterns and multiple sclerosis (MS) risk have been studied for a long time, with conflicting results. We aimed to investigate the influence of reproductive history on MS risk. Using a Swedish population-based case-control study involving incident cases of MS (1798 cases, 3907 controls), we calculated odds ratios (OR) for MS comparing parents with childless subjects together with 95% confidence intervals (CI) employing logistic regression. Overall, there was an association between having children and reduced MS risk among both sexes. Subjects who had become parents within five years prior to the index year had a substantially reduced risk of developing MS (OR 0.6, 95% CI 0.5-0.8 for women, and OR 0.4, 95% CI 0.3-0.6 for men). No association between having children and MS risk was observed when more than 10 years had passed since the birth of the last child. We found no association between increasing offspring number and MS risk. The observed association between reproductive history and MS risk is restricted to a limited time period preceding the index year, with similar findings in both sexes, which contradicts biologic impact of pregnancy on MS risk and argues in favor of reverse causality, i.e. that fecundity is affected by yet-undiagnosed MS.

  1. Spondias tuberosa (Anacardiaceae) leaves: profiling phenolic compounds by HPLC-DAD and LC-MS/MS and in vivo anti-inflammatory activity.

    PubMed

    da Silva Siqueira, Emerson Michell; Félix-Silva, Juliana; de Araújo, Lorena Maria Lima; Fernandes, Julia Morais; Cabral, Bárbara; Gomes, Jacyra Antunes Dos Santos; de Araújo Roque, Alan; Tomaz, José Carlos; Lopes, Norberto Peporine; de Freitas Fernandes-Pedrosa, Matheus; Giordani, Raquel Brandt; Zucolotto, Silvana Maria

    2016-10-01

    Spondias tuberosa is a medicinal plant used by several local communities in northeast Brazil to treat infections, digestive disorders and inflammatory conditions. The study aimed to identify and quantify the major phenolic in hydroethanolic extract of leaves from S. tuberosa and to evaluate its anti-inflammatory potential. The chemical profile of extract was analyzed by HPLC-DAD and HPLC-MS. The in vivo anti-inflammatory activity was investigated in carrageenan-induced hind paw edema and peritonitis models in mice. Identified and quantified through HPLC-DAD or HPLC-MS analyses of S. tuberosa extract were the following compounds: chlorogenic acid, caffeic acid, rutin and isoquercitrin. The inflammatory response to carrageenan was significantly reduced in both models by S. tuberosa extract. In hind paw edema, the edematogenic response was reduced by up to 63.6% and the myeloperoxidase activity was completely inhibited. In the peritonitis model, the total cell migration into the peritoneal cavity was reduced by up to 65%. The results obtained give evidence of the anti-inflammatory action of S. tuberosa and suggest the potential therapeutic benefit of this plant on inflammatory conditions. The chlorogenic acid, caffeic acid, rutin and isoquercitrin identified and quantified in S. tuberosa leaves enable us to suggest that these compounds could be used as chemical markers for quality control of derivative products from this species. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Identification of bacteria isolated from veterinary clinical specimens using MALDI-TOF MS.

    PubMed

    Pavlovic, Melanie; Wudy, Corinna; Zeller-Peronnet, Veronique; Maggipinto, Marzena; Zimmermann, Pia; Straubinger, Alix; Iwobi, Azuka; Märtlbauer, Erwin; Busch, Ulrich; Huber, Ingrid

    2015-01-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has recently emerged as a rapid and accurate identification method for bacterial species. Although it has been successfully applied for the identification of human pathogens, it has so far not been well evaluated for routine identification of veterinary bacterial isolates. This study was performed to compare and evaluate the performance of MALDI-TOF MS based identification of veterinary bacterial isolates with commercially available conventional test systems. Discrepancies of both methods were resolved by sequencing 16S rDNA and, if necessary, the infB gene for Actinobacillus isolates. A total of 375 consecutively isolated veterinary samples were collected. Among the 357 isolates (95.2%) correctly identified at the genus level by MALDI-TOF MS, 338 of them (90.1% of the total isolates) were also correctly identified at the species level. Conventional methods offered correct species identification for 319 isolates (85.1%). MALDI-TOF identification therefore offered more accurate identification of veterinary bacterial isolates. An update of the in-house mass spectra database with additional reference spectra clearly improved the identification results. In conclusion, the presented data suggest that MALDI-TOF MS is an appropriate platform for classification and identification of veterinary bacterial isolates.

  3. Assessing direct analysis in real-time-mass spectrometry (DART-MS) for the rapid identification of additives in food packaging.

    PubMed

    Ackerman, L K; Noonan, G O; Begley, T H

    2009-12-01

    The ambient ionization technique direct analysis in real time (DART) was characterized and evaluated for the screening of food packaging for the presence of packaging additives using a benchtop mass spectrometer (MS). Approximate optimum conditions were determined for 13 common food-packaging additives, including plasticizers, anti-oxidants, colorants, grease-proofers, and ultraviolet light stabilizers. Method sensitivity and linearity were evaluated using solutions and characterized polymer samples. Additionally, the response of a model additive (di-ethyl-hexyl-phthalate) was examined across a range of sample positions, DART, and MS conditions (temperature, voltage and helium flow). Under optimal conditions, molecular ion (M+H+) was the major ion for most additives. Additive responses were highly sensitive to sample and DART source orientation, as well as to DART flow rates, temperatures, and MS inlet voltages, respectively. DART-MS response was neither consistently linear nor quantitative in this setting, and sensitivity varied by additive. All additives studied were rapidly identified in multiple food-packaging materials by DART-MS/MS, suggesting this technique can be used to screen food packaging rapidly. However, method sensitivity and quantitation requires further study and improvement.

  4. Validation and use of three complementary analytical methods (LC-FLS, LC-MS/MS and ICP-MS) to evaluate the pharmacokinetics, biodistribution and stability of motexafin gadolinium in plasma and tissues.

    PubMed

    Miles, Dale R; Mesfin, Mimi; Mody, Tarak D; Stiles, Mark; Lee, Jean; Fiene, John; Denis, Bernie; Boswell, Garry W

    2006-05-01

    Liquid chromatography-fluorescence (LC-FLS), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-mass spectrometry (ICP-MS) methods were developed and validated for the evaluation of motexafin gadolinium (MGd, Xcytrin) pharmacokinetics and biodistribution in plasma and tissues. The LC-FLS method exhibited the greatest sensitivity (0.0057 microg mL(-1)), and was used for pharmacokinetic, biodistribution, and protein binding studies with small sample sizes or low MGd concentrations. The LC-MS/MS method, which exhibited a short run time and excellent selectivity, was used for routine clinical plasma sample analysis. The ICP-MS method, which measured total Gd, was used in conjunction with LC methods to assess MGd stability in plasma. All three methods were validated using human plasma. The LC-FLS method was also validated using plasma, liver and kidneys from mice and rats. All three methods were shown to be accurate, precise and robust for each matrix validated. For three mice, the mean (standard deviation) concentration of MGd in plasma/tissues taken 5 hr after dosing with 23 mg kg(-1) MGd was determined by LC-FLS as follows: plasma (0.025+/-0.002 microg mL(-1)), liver (2.89+/-0.45 microg g(-1)), and kidney (6.09+/-1.05 microg g(-1)). Plasma samples from a subset of patients with brain metastases from extracranial tumors were analyzed using both LC-MS/MS and ICP-MS methods. For a representative patient, > or = 90% of the total Gd in plasma was accounted for as MGd over the first hour post dosing. By 24 hr post dosing, 63% of total Gd was accounted for as MGd, indicating some metabolism of MGd.

  5. Trace element analysis of rough diamond by LA-ICP-MS: a case of source discrimination?

    PubMed

    Dalpé, Claude; Hudon, Pierre; Ballantyne, David J; Williams, Darrell; Marcotte, Denis

    2010-11-01

    Current profiling of rough diamond source is performed using different physical and/or morphological techniques that require strong knowledge and experience in the field. More recently, chemical impurities have been used to discriminate diamond source and with the advance of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) empirical profiling of rough diamonds is possible to some extent. In this study, we present a LA-ICP-MS methodology that we developed for analyzing ultra-trace element impurities in rough diamond for origin determination ("profiling"). Diamonds from two sources were analyzed by LA-ICP-MS and were statistically classified by accepted methods. For the two diamond populations analyzed in this study, binomial logistic regression produced a better overall correct classification than linear discriminant analysis. The results suggest that an anticipated matrix match reference material would improve the robustness of our methodology for forensic applications. © 2010 American Academy of Forensic Sciences.

  6. Techniques for quantitative LC-MS/MS analysis of protein therapeutics: advances in enzyme digestion and immunocapture.

    PubMed

    Fung, Eliza N; Bryan, Peter; Kozhich, Alexander

    2016-04-01

    LC-MS/MS has been investigated to quantify protein therapeutics in biological matrices. The protein therapeutics is digested by an enzyme to generate surrogate peptide(s) before LC-MS/MS analysis. One challenge is isolating protein therapeutics in the presence of large number of endogenous proteins in biological matrices. Immunocapture, in which a capture agent is used to preferentially bind the protein therapeutics over other proteins, is gaining traction. The protein therapeutics is eluted for digestion and LC-MS/MS analysis. One area of tremendous potential for immunocapture-LC-MS/MS is to obtain quantitative data where ligand-binding assay alone is not sufficient, for example, quantitation of antidrug antibody complexes. Herein, we present an overview of recent advance in enzyme digestion and immunocapture applicable to protein quantitation.

  7. Cognitive behavioural therapy for MS-related fatigue explained: A longitudinal mediation analysis.

    PubMed

    van den Akker, L E; Beckerman, H; Collette, E H; Knoop, H; Bleijenberg, G; Twisk, J W; Dekker, J; de Groot, V

    2018-03-01

    Cognitive behavioural therapy (CBT) effectively reduces fatigue directly following treatment in patients with Multiple Sclerosis (MS), but little is known about the process of change during and after CBT. Additional analysis of a randomized clinical trial. To investigate which psychological factors mediate change in fatigue during and after CBT. TREFAMS-CBT studied the effectiveness of a 16-week CBT treatment for MS-related fatigue. Ninety-one patients were randomized (44 to CBT, 47 to the MS-nurse consultations). Mediation during CBT treatment was studied using assessments at baseline, 8 and 16weeks. Mediation of the change in fatigue from post-treatment to follow-up was studied separately using assessments at 16, 26 and 52weeks. Proposed mediators were: changes in illness cognitions, general self-efficacy, coping styles, daytime sleepiness, concentration and physical activity, fear of disease progression, fatigue perceptions, depression and physical functioning. Mediators were separately analysed according to the product-of-coefficients approach. Confidence intervals were calculated with a bootstrap procedure. During treatment the decrease in fatigue brought on by CBT was mediated by improved fatigue perceptions, increased physical activity, less sleepiness, less helplessness, and improved physical functioning. Post-treatment increases in fatigue levels were mediated by reduced physical activity, reduced concentration, and increased sleepiness. These results suggests that focusing on improving fatigue perceptions, perceived physical activity, daytime sleepiness, helplessness, and physical functioning may further improve the effectiveness of CBT for fatigue in patients with MS. Maintenance of treatment effects may be obtained by focusing on improving physical activity, concentration and sleepiness. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. GC-MS, LC-MS(n), LC-high resolution-MS(n), and NMR studies on the metabolism and toxicological detection of mesembrine and mesembrenone, the main alkaloids of the legal high "Kanna" isolated from Sceletium tortuosum.

    PubMed

    Meyer, Golo M J; Wink, Carina S D; Zapp, Josef; Maurer, Hans H

    2015-01-01

    Mesembrine and mesembrenone are the main alkaloids of Sceletium tortuosum, a plant species that was used for sedation and analgesia by the KhoiSan, previously known as Hottentots, a tribe in South Africa. After fermentation, the obtained preparation called "Kanna" or "Kougoed" was used by chewing, smoking, or sniffing. Today, Kanna gains popularity by drug users as legal high. For monitoring such consumption, metabolism studies are mandatory because the metabolites are mostly the analytical targets, especially in urine. Therefore, the metabolism of both alkaloids was investigated in rat urine and pooled human liver preparations after several sample work-up procedures. As both alkaloids were not commercially available, they were isolated from plant material by Soxhlet extraction, and their identity confirmed by NMR. The metabolites were identified using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography coupled to linear ion trap high resolution mass spectrometry (LC-HR-MS(n)). Both alkaloids were O- and N-demethylated, dihydrated, and/or hydroxylated at different positions. The phenolic metabolites were partly excreted as glucuronides and/or sulfates. Most of the phase I metabolites identified in rat urine could be detected also in the human liver preparations. After a common user's low dose application of mesembrine, mainly the O- and N demethyl-dihydro, hydroxy, and bis-demethyl-dihydro metabolites, and in case of mesembrenone only the N-demethyl and the N-demethyl-dihydro metabolite could be detected in rat urine using the authors' standard urine screening approaches (SUSA) by GC-MS or LC-MS(n). Thus, it should be possible to monitor a consumption of mesembrine and/or mesembrenone assuming similar pharmacokinetics in humans.

  9. Salivary hormone measurement using LC/MS/MS: specific and patient-friendly tool for assessment of endocrine function.

    PubMed

    Higashi, Tatsuya

    2012-01-01

    Saliva has recently been attracting attention as a patient-friendly available bio-fluid and an alternative to serum/plasma for hormone tests. LC coupled with atmospheric pressure ionization-MS/MS, especially electrospray ionization (ESI)-MS/MS, has been recently valued as a highly specific method in the analysis of salivary hormones. In this article, LC/ESI-MS/MS assays for salivary hormones are overviewed according to the papers that have been published during the last 5 years. Practical derivatization to enhance the detectabilities of hormones in ESI-MS/MS is also discussed, because a major disadvantage of using saliva is low hormone concentrations.

  10. Multimycotoxin UPLC-MS/MS for tea, herbal infusions and the derived drinkable products.

    PubMed

    Monbaliu, Sofie; Wu, Aibo; Zhang, Dabing; Van Peteghem, Carlos; De Saeger, Sarah

    2010-12-22

    In recent years the consumption of tea and herbal infusions has increased. These hot drinks are consumed as daily drinks as well as for medicinal purposes. All tea varieties (white, yellow, green, oolong, black and puerh) originate from the leaves of the tea plant, Camellia sinensis. All extracts made of plant or herbal materials which do not contain Camellia sinensis are referred as herbal infusions or tisanes. During processing and manufacturing fungal contamination of the plant materials is possible, enabling contamination of these products with mycotoxins. In this study a multimycotoxin UPLC-MS/MS method was developed and validated for the analysis of the raw tea and herbal infusion materials as well as for their drinkable products. The samples were analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), with a mobile phase consisting of variable mixtures of water and methanol with 0.3% formic acid. The limits of detection for the different mycotoxins varied between 2.1 μg/kg and 121 μg/kg for raw materials and between 0.4 μg/L and 46 μg/L for drinkable products. Afterward 91 different tea and herbal infusion samples were analyzed. Only in one sample, Ceylon melange, 76 μg/kg fumonisin B(1) was detected. No mycotoxins were detected in the drinkable products.

  11. Social cognition in pediatric-onset multiple sclerosis (MS)

    PubMed Central

    Charvet, LE; Cleary, RE; Vazquez, K; Belman, A; Krupp, LB

    2014-01-01

    Background Pediatric-onset multiple sclerosis (MS) patients represent a subpopulation who are diagnosed during the course of development. Social cognitive deficits have recently been recognized in adults with MS. It is critical to identify if these youngest patients with the disorder are also at risk. Objective To determine whether pediatric-onset MS is associated with social cognitive deficits. Methods Consecutively-recruited participants with pediatric-onset MS were compared to a group of age- and gender-matched healthy controls on Theory of Mind (ToM) task performance. Tasks measured facial affect recognition (Reading the Mind in the Eyes Test), understanding social faux pas (Faux Pas Test), and understanding the perspective of another (False Beliefs Task). Results Twenty-eight (28) pediatric-onset MS participants (median age 17 years) and 32 healthy controls (median age 16 years) completed the study. The MS participants performed worse than controls on all three ToM tasks: Reading the Mind in the Eyes Test (p=0.008), the Faux-Pas Test (p=0.009), and the False Beliefs Task (p=0.06). While more MS than control participants were impaired on a measure of information processing speed (the Symbol Digit Modalities Test; 38% versus 6%), it did not account for the differences in ToM performance. Conclusions Social cognition may represent an area of cognitive functioning affected by MS in the pediatric-onset population. These processes are especially important to study in younger patients as these deficits could have long range implications on social adjustment, employment, and well-being. PMID:24647558

  12. Social cognition in pediatric-onset multiple sclerosis (MS).

    PubMed

    Charvet, L E; Cleary, R E; Vazquez, K; Belman, A L; Krupp, L B

    2014-10-01

    Pediatric-onset multiple sclerosis (MS) patients represent a subpopulation who are diagnosed during the course of development. Social cognitive deficits have recently been recognized in adults with MS. It is critical to identify whether these youngest patients with the disorder are also at risk. To determine whether pediatric-onset MS is associated with social cognitive deficits. Consecutively-recruited participants with pediatric-onset MS were compared to a group of age- and gender-matched healthy controls on Theory of Mind (ToM) task performance. Tasks measured facial affect recognition (Reading the Mind in the Eyes Test), detecting social faux pas (Faux Pas Test), and understanding the perspective of another (False Beliefs Task). Twenty-eight (28) pediatric-onset MS participants (median age 17 years) and 32 healthy controls (median age 16 years) completed the study. The MS participants performed worse than controls on all three ToM tasks: Reading the Mind in the Eyes Test (p = 0.008), the Faux Pas Test (p = 0.009), and the False Beliefs Task (p = 0.06). While more MS than control participants were impaired on a measure of information processing speed (the Symbol Digit Modalities Test; 38% versus 6%), it did not account for the differences in ToM performance. Social cognition may represent an area of cognitive functioning affected by MS in the pediatric-onset population. These processes are especially important to study in younger patients as they may have long range implications for social adjustment, employment, and well-being. © The Author(s) 2014.

  13. Simultaneous determination of mequindox, quinocetone, and their major metabolites in chicken and pork by UPLC-MS/MS.

    PubMed

    Li, Yanshen; Liu, Kaili; Beier, Ross C; Cao, Xingyuan; Shen, Jianzhong; Zhang, Suxia

    2014-10-01

    This report presents a UPLC-MS/MS method for determination of mequindox (MEQ), quinocetone (QCT) and their 11 metabolites in chicken and pork samples. Following extraction process with acetonitrile-ethyl acetate, acidulation, and re-extraction with ethyl acetate in turn, target analytes were further purified using C18 solid phase extraction (SPE) cartridges for UPLC-MS/MS analysis. Validation was processed with mean recoveries from 69.1% to 113.3% with intra-day relative standard deviation (RSD) <14.7%, inter-day RSD <19.2%, and limit of detection between 0.05 and 1.0 μg/kg for each analytes. The verified method was successfully applied to the quantitative determination of commercial samples. This developed procedure will help to control food animal products with MEQ and QCT residues, and facilitate further pharmacokinetic and residue studies of similar quinoxaline-1,4-dioxide veterinary drugs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Wavelet-Based Peak Detection and a New Charge Inference Procedure for MS/MS Implemented in ProteoWizard’s msConvert

    PubMed Central

    2015-01-01

    We report the implementation of high-quality signal processing algorithms into ProteoWizard, an efficient, open-source software package designed for analyzing proteomics tandem mass spectrometry data. Specifically, a new wavelet-based peak-picker (CantWaiT) and a precursor charge determination algorithm (Turbocharger) have been implemented. These additions into ProteoWizard provide universal tools that are independent of vendor platform for tandem mass spectrometry analyses and have particular utility for intralaboratory studies requiring the advantages of different platforms convergent on a particular workflow or for interlaboratory investigations spanning multiple platforms. We compared results from these tools to those obtained using vendor and commercial software, finding that in all cases our algorithms resulted in a comparable number of identified peptides for simple and complex samples measured on Waters, Agilent, and AB SCIEX quadrupole time-of-flight and Thermo Q-Exactive mass spectrometers. The mass accuracy of matched precursor ions also compared favorably with vendor and commercial tools. Additionally, typical analysis runtimes (∼1–100 ms per MS/MS spectrum) were short enough to enable the practical use of these high-quality signal processing tools for large clinical and research data sets. PMID:25411686

  15. Fine mapping of the genic male-sterile ms 1 gene in Capsicum annuum L.

    PubMed

    Jeong, Kyumi; Choi, Doil; Lee, Jundae

    2018-01-01

    The genomic region cosegregating with the genic male-sterile ms 1 gene of Capsicum annuum L. was delimited to a region of 869.9 kb on chromosome 5 through fine mapping analysis. A strong candidate gene, CA05g06780, a homolog of the Arabidopsis MALE STERILITY 1 gene that controls pollen development, was identified in this region. Genic male sterility caused by the ms 1 gene has been used for the economically efficient production of massive hybrid seeds in paprika (Capsicum annuum L.), a colored bell-type sweet pepper. Previously, a CAPS marker, PmsM1-CAPS, located about 2-3 cM from the ms 1 locus, was reported. In this study, we constructed a fine map near the ms 1 locus using high-resolution melting (HRM) markers in an F 2 population consisting of 1118 individual plants, which segregated into 867 male-fertile and 251 male-sterile plants. A total of 12 HRM markers linked to the ms 1 locus were developed from 53 primer sets targeting intraspecific SNPs derived by comparing genome-wide sequences obtained by next-generation resequencing analysis. Using this approach, we narrowed down the region cosegregating with the ms 1 gene to 869.9 kb of sequence. Gene prediction analysis revealed 11 open reading frames in this region. A strong candidate gene, CA05g06780, was identified; this gene is a homolog of the Arabidopsis MALE STERILITY 1 (MS1) gene, which encodes a PHD-type transcription factor that regulates pollen and tapetum development. Sequence comparison analysis suggested that the CA05g06780 gene is the strongest candidate for the ms 1 gene of paprika. To summarize, we developed a cosegregated marker, 32187928-HRM, for marker-assisted selection and identified a strong candidate for the ms 1 gene.

  16. Effect of temperature on thermal oxidation of palmitic acid studied by combination of EPR spin trapping technique and SPME-GC-MS/MS.

    PubMed

    Chen, Hongjian; Wang, Yong; Cao, Peirang; Liu, Yuanfa

    2017-11-01

    Effect of temperatures on thermal oxidation of palmitic acid was studied by the combination of EPR and GC-MS/MS. DMPO was used as the spin trap. The experimental spectrum was simulated with alkyl and alkoxyl spin adducts. Total amount of spins, a parameter to indicate radical concentrations, detected at 180°C was nearly 10 times higher than that at 175°C. Besides, total amounts of spins detected at 180°C decreased rapidly because of the reaction between radical adducts and newly formed radicals. Signal intensities of alkyl radical adducts increased rapidly from 0.405 to 4.785 from 175°C to 180°C. Besides, more palmitic acid degraded to oxidized compounds from 175°C to 180°C than that of other temperature ranges. The C-C linkages between carbons 2 to 6 were easier to be oxidized at 180°C. The results all implied that oxidation rates of palmitic acid samples increased rapidly from 175°C to 180°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Analyses via automated mass spectrometry (MS/DS)

    NASA Technical Reports Server (NTRS)

    Koenig, T.

    1985-01-01

    New or improved uses of the Finnigan 4000 quadrupole mass spectrometer (MS) with its associated INCOS data system (DS) were investigated. The first phase involved an evaluative activity in which specific problems with miscalibration and gas chromatographic column conditioning were identified. This also revealed one solution to the problem of detection of substances not visible in the gas chromatography detection mode. A second phase was to seek useful applications of the direct inlet systems. This mode of sample introduction has not been previously utilized on the existing equipment and was successfully applied to the analysis of the components of TONOX 60/40 and in the thermal degradation products of some polymeric materials. Suggestions are made for improving and expanding the use of the MS/DS system in materials development and testing.

  18. Effect of glatiramer acetate on disease reactivation in MS patients discontinuing natalizumab.

    PubMed

    Rossi, S; Motta, C; Studer, V; De Chiara, V; Barbieri, F; Monteleone, F; Fornasiero, A; Coarelli, G; Bernardi, G; Cutter, G; Stüve, O; Salvetti, M; Centonze, D

    2013-01-01

    Multiple sclerosis (MS) patients discontinuing natalizumab are at risk of rebound of disease activity. In the present multi-center, open-label, non-randomized, prospective, pilot study, we tested whether treatment with glatiramer acetate (GA) is safe and effective after natalizumab in MS patients. The study was performed at academic tertiary medical centers. Forty active relapsing-remitting MS patients who never failed GA therapy and who discontinued natalizumab after 12-18 months of therapy were enrolled. GA was initiated 4 weeks after the last dose of natalizumab. 62.5% of patients were relapse-free 12 months after GA initiation. Annualized relapse rate and time to relapse were significantly lower than before natalizumab. Notably, the frequency of relapses was significantly lower amongst those patients who had experienced ≤2 relapses the year before initiation of natalizumab therapy, compared with patients who had had three or more relapses. No evidence of rebound was observed in magnetic resonance imaging scans. Furthermore, Expanded Disability Status Scale and Multiple Sclerosis Functional Composite were stable in our patients, again suggesting that 12 months of post-natalizumab-GA therapy is not associated with clinical deterioration. Following discontinuation of natalizumab, 12 months of therapy with GA is safe and well tolerated in MS patients. GA can reduce the risk of early reactivation/rebound of disease activity in this setting. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  19. Alzheimer's disease susceptibility variants in the MS4A6A gene are associated with altered levels of MS4A6A expression in blood.

    PubMed

    Proitsi, Petroula; Lee, Sang Hyuck; Lunnon, Katie; Keohane, Aoife; Powell, John; Troakes, Claire; Al-Sarraj, Safa; Furney, Simon; Soininen, Hilkka; Kłoszewska, Iwona; Mecocci, Patrizia; Tsolaki, Magda; Vellas, Bruno; Lovestone, Simon; Hodges, Angela

    2014-02-01

    An increased risk of developing Alzheimer's disease (AD) has previously been found to be associated with variants at the MS4A6A locus. We sought to identify which genes and transcripts in this region have altered expression in AD and mild cognitive impairment (MCI) and are influenced by the AD risk variant(s), as a first step to understanding the molecular basis of AD susceptibility at this locus. Common variants located within highly expressed MS4A6A transcripts were significantly associated with AD and MS4A6A expression levels in blood from MCI and AD subjects (p < 0.05, rs610932, rs7232, rs583791). More copies of the protective (minor) allele were associated with lower MS4A6A expression of each transcript (e.g., p = 0.019; rs610932-total MS4A6A). Furthermore, in heterozygous AD subjects, relative expression of the protective allele of V4-MS4A6A transcripts was lower (p < 0.008). Irrespective of genotype, MS4A6A transcripts were increased in blood from people with AD (p < 0.003), whereas lower expression of full length V1-MS4A6A (p = 0.002) and higher expression of V4-MS4A6A (p = 1.8 × 10(-4)) were observed in MCI, relative to elderly controls. The association between genotype and expression was less consistent in brain, although BA9 did have a similar genotype association with V4-MS4A6A transcripts as in blood. MS4A6A transcripts were widely expressed in tissues and cells, with the exception of V4-MS4A6A, which was not expressed in neuronal cells. Together these results suggest that high levels of MS4A6A in emerging AD pathology are detrimental. Persons with MCI may lower MS4A6A expression to minimize detrimental disease associated MS4A6A activity. However, those with the susceptibility allele appear unable to decrease expression sufficiently, which may explain their increased risk for developing AD. Inhibiting MS4A6A may therefore promote a more neuroprotective phenotype, although further work is needed to establish whether this is the case. Copyright © 2014

  20. Investigation of the metabolism of substance P at the blood-brain barrier using LC-MS/MS.

    PubMed

    Chappa, Arvind K; Cooper, Joshua D; Audus, Kenneth L; Lunte, Susan M

    2007-03-12

    Substance P (SP) has been associated with pain and depression as well as neurodegenerative diseases. Many of these diverse actions of SP can potentially be attributed to SP metabolites generated at the blood-brain barrier (BBB). In this study, the metabolism of SP was investigated using an in vitro model of the BBB and LC-MS/MS. Substance P metabolism was found to be non-saturable in the concentration range of 100 nM to 10 microM, with approximately 70% of the peptide remaining intact after 5 h. The major metabolites of SP were identified by MS as 3-11 and 5-11. Two previously unreported metabolites, 5-11 and 6-11, were also found in our studies. Several additional minor SP metabolites, including 1-9 and 2-11, were also identified. A profile of the SP metabolites generated by the BBB over time was obtained. The results from the present study provide a better understanding of the role of the blood-brain barrier in the pharmacology of SP.

  1. INVESTIGATION OF THE METABOLISM OF SUBSTANCE P AT THE BLOOD-BRAIN BARRIER USING LC-MS/MS

    PubMed Central

    Chappa, Arvind K.; Cooper, Joshua D.; Audus, Kenneth L.; Lunte, Susan M.

    2007-01-01

    Substance P (SP) has been associated with pain and depression as well as neurodegenerative diseases. Many of these diverse actions of SP can potentially be attributed to SP metabolites generated at the blood-brain barrier (BBB). In this study, the metabolism of SP was investigated using an in vitro model of the BBB and LC-MS/MS. Substance P metabolism was found to be non-saturable in the concentration range of 100 nM to 10 μM, with approximately 70% of the peptide remaining intact after 5 h. The major metabolites of SP were identified by MS as 3-11 and 5-11. Two previously unreported metabolites, 5-11 and 6-11, were also found in our studies. Several additional minor SP metabolites, including 1-9 and 2-11, were also identified. A profile of the SP metabolites generated by the BBB over time was obtained. The results from the present study provide us a better understanding of the role of the blood-brain barrier in the pharmacology of SP. PMID:17118606

  2. MS/MS Automated Selected Ion Chromatograms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Monroe, Matthew

    2005-12-12

    This program can be used to read a LC-MS/MS data file from either a Finnigan ion trap mass spectrometer (.Raw file) or an Agilent Ion Trap mass spectrometer (.MGF and .CDF files) and create a selected ion chromatogram (SIC) for each of the parent ion masses chosen for fragmentation. The largest peak in each SIC is also identified, with reported statistics including peak elution time, height, area, and signal to noise ratio. It creates several output files, including a base peak intensity (BPI) chromatogram for the survey scan, a BPI for the fragmentation scans, an XML file containing the SICmore » data for each parent ion, and a "flat file" (ready for import into a database) containing summaries of the SIC data statistics.« less

  3. Analysis of anabolic steroids in human hair using LC-MS/MS.

    PubMed

    Deshmukh, Nawed; Hussain, Iltaf; Barker, James; Petroczi, Andrea; Naughton, Declan P

    2010-10-01

    New highly sensitive, specific, reliable, reproducible and robust LC-MS/MS methods were developed to detect the anabolic steroids, nandrolone and stanozolol, in human hair for the first time. Hair samples from 180 participants (108 males, 72 females, 62% athletes) were screened using ELISA which revealed 16 athletes as positive for stanozolol and 3 for nandrolone. Positive samples were confirmed on LC-MS/MS in selective reaction monitoring (SRM) mode. The assays for stanozolol and nandrolone showed good linearity in the range 1-400pg/mg and 5-400pg/mg, respectively. The methods were validated for LLOD, interday precision, intraday precision, specificity, extraction recovery and accuracy. The assays were capable of detecting 0.5pg stanozolol and 3.0pg nandrolone per mg of hair, when approximately 20mg of hair were processed. Analysis using LC-MS/MS confirmed 11 athletes' positive for stanozolol (5.0pg/mg to 86.3pg/mg) and 1 for nandrolone (14.0pg/mg) thus avoiding false results from ELISA screening. The results obtained demonstrate the application of these hair analysis methods to detect both steroids at low concentrations, hence reducing the amount of hair required significantly. The new methods complement urinalysis or blood testing and facilitate improved doping testing regimes. Hair analysis benefits from non-invasiveness, negligible risk of infection and facile sample storage and collection, whilst reducing risks of tampering and cross-contamination. Owing to the wide detection window, this approach may also offer an alternative approach for out-of-competition testing.

  4. Mycobiota and Natural Incidence of Aflatoxins, Ochratoxin A, and Citrinin in Indian Spices Confirmed by LC-MS/MS

    PubMed Central

    Jeswal, Punam; Kumar, Dhiraj

    2015-01-01

    Nine different Indian spices (red chilli, black pepper, turmeric, coriander, cumin, fennel, caraway, fenugreek, and dry ginger) commonly cultivated and highly used in India were analysed for natural occurrence of toxigenic mycoflora and aflatoxins (AFs), ochratoxin A (OTA), and citrinin (CTN) contamination. Aspergillus flavus and Aspergillus niger were the most dominant species isolated from all types of spices. Red chilli samples were highly contaminated with aflatoxins (85.4%) followed by dry ginger (77.7%). 56% Aspergillus flavus from red chilli and 45% Aspergillus ochraceus from black pepper were toxigenic and produced aflatoxins and ochratoxin A, respectively. Qualitative detection and quantitative detection of mycotoxins in spices were analyzed by ELISA and further confirmed by LC-MS/MS. Penicillium citrinum produced citrinin in red chilli, black pepper, coriander, cumin, fenugreek, and dry ginger samples. The highest amount of AFs was found in red chilli (219.6 ng/g), OTA was in black pepper (154.1 ng/g), and CTN was in dry ginger samples (85.1 ng/g). The results of this study suggest that the spices are susceptible substrate for growth of mycotoxigenic fungi and further mycotoxin production. This is the first report of natural occurrence of citrinin in black pepper and dry ginger from India. PMID:26229535

  5. Characterization and quantification of the chemical compositions of Scutellariae Barbatae herba and differentiation from its substitute by combining UHPLC-PDA-QTOF-MS/MS with UHPLC-MS/MS.

    PubMed

    Zhang, Zhifeng; He, Lili; Lu, Luyang; Liu, Yuan; Dong, Gengting; Miao, Jianhua; Luo, Pei

    2015-05-10

    The aim of this study was to investigate the possibility of using the non-official species Scutellaria indica L. as the substitute for the official species Scutellaria barbata D. Don. A sensitive, precise and accurate method was developed to identify their chemical compositions from the crude extracts using UHPLC-PDA-QTOF-MS/MS. 36 peaks were detected and 28 peaks have been tentatively and structurally characterized by comparing their retention times, UV spectra and HR-MS data with those of the reference substances and/or the data of the literatures. Additionally, 5 flavonoids have been quantified by multiple reaction monitoring (MRM) in the negative ionization mode. The results demonstrated that there were 23 common peaks between these two species. However, the other 13 peaks from S. barbata could not be detected in S. indica. Furthermore, the content of 5 flavonoids is significantly different. Scutellarein cannot be detected in S. indica, which was considered as the characteristic component for distinguishing the two species. Our data, therefore, clearly demonstrate that S. indica may not be used as the substitute for S. barbata and further investigation is needed to determine through investigation of their therapeutic efficacy. Copyright © 2015. Published by Elsevier B.V.

  6. Investigation of Imposter Perfumes Using GC-MS

    ERIC Educational Resources Information Center

    Mowery, Kelly A.; Blanchard, Daniel E.; Smith, Stephanie; Betts, Thomas A.

    2004-01-01

    An experiment to initiate students into several features of gas chromatograph-mass spectrometers (GC-MS) through the study of branded and counterfeit perfumes is described. The experiment enables the students to appreciate the power of GC-MS in distinguishing between original and imitation perfumes, and in analyzing data with its application…

  7. Practical utilization of spICP-MS to study sucrose density gradient centrifugation for the separation of nanoparticles.

    PubMed

    Johnson, Monique E; Montoro Bustos, Antonio R; Winchester, Michael R

    2016-11-01

    Single particle inductively coupled plasma mass spectrometry (spICP-MS) is shown to be a practical technique to study the efficacy of rate-zonal sucrose density gradient centrifugation (SDGC) separations of mixtures of gold nanoparticles (AuNPs) in liquid suspension. spICP-MS enabled measurements of AuNP size distributions and particle number concentrations along the gradient, allowing unambiguous evaluations of the effectiveness of the separation. Importantly, these studies were conducted using AuNP concentrations that are directly relevant to environmental studies (sub ng mL -1 ). At such low concentrations, other techniques [e.g., dynamic light scattering (DLS), transmission and scanning electron microscopies (TEM and SEM), UV-vis spectroscopy, atomic force microscopy (AFM)] do not have adequate sensitivity, highlighting the inherent value of spICP-MS for this and similar applications. In terms of the SDGC separations, a mixture containing three populations of AuNPs, having mean diameters of 30, 80, and 150 nm, was fully separated, while separations of two other mixtures (30, 60, 100 nm; and 20, 50, 100 nm) were less successful. Finally, it is shown that the separation capacity of SDGC can be overwhelmed when particle number concentrations are excessive, an especially relevant finding in view of common methodologies taken in nanotechnology research. Graphical Abstract Characterization of the separation of a gold nanoparticle mixture by sucrose density gradient centrifugation by conventional and single particle ICP-MS analysis.

  8. Isolation and analysis of a multifunctional triterpene synthase KcMS promoter region from mangrove plant kandelia candel

    NASA Astrophysics Data System (ADS)

    Basyuni, M.; Wati, R.; Sulistiyono, N.; Sumardi; Oku, H.; Baba, S.; Sagami, H.

    2018-03-01

    Molecular cloning of Kandelia candel KcMS gene has previously been cloned and encoded a multifunctional triterpene synthase. In this study, the KcMS gene promoter was cloned through Genome walking, sequenced, and analyzed. A 1,358 bp genomic DNA fragment of KcMS promoter was obtained. PLACE and PlantCARE analysis of the KcMS promoter revealed that there was some regulatory elements in response to environmental signals and involved in the regulation of gene expression. Results showed that four kinds of elements are regulated by hormone binding, namely 2 MeJA-responsiveness elements (CGTCA-motif and TGACG-motif), the ABRE (TACGTG) involved in abscisic acid responsiveness, gibberellin-related GARE-motif (AAACAGA), and the TGA-element (AACGAC) as an auxin-responsive element. Several elements in the KcMS have been shown in other plants to be responsive to abiotic stress. These motifs were MBS (CAACTG), TC-rich repeats, and eight light responsive elements. The KcMS promoter was also involved in the activation of defense genes in plants such as HSE (AAAAAATTC) and four circadian control elements (CAANNNNATC). The presence of multipotential regulatory motifs suggested that KcMS may be involved in regulation of plant tolerance to several types of stresses.

  9. Urine metabolic fingerprinting using LC-MS and GC-MS reveals metabolite changes in prostate cancer: A pilot study.

    PubMed

    Struck-Lewicka, Wiktoria; Kordalewska, Marta; Bujak, Renata; Yumba Mpanga, Arlette; Markuszewski, Marcin; Jacyna, Julia; Matuszewski, Marcin; Kaliszan, Roman; Markuszewski, Michał J

    2015-01-01

    Prostate cancer (CaP) is a leading cause of cancer deaths in men worldwide. The alarming statistics, the currently applied biomarkers are still not enough specific and selective. In addition, pathogenesis of CaP development is not totally understood. Therefore, in the present work, metabolomics study related to urinary metabolic fingerprinting analyses has been performed in order to scrutinize potential biomarkers that could help in explaining the pathomechanism of the disease and be potentially useful in its diagnosis and prognosis. Urine samples from CaP patients and healthy volunteers were analyzed with the use of high performance liquid chromatography coupled with time of flight mass spectrometry detection (HPLC-TOF/MS) in positive and negative polarity as well as gas chromatography hyphenated with triple quadruple mass spectrometry detection (GC-QqQ/MS) in a scan mode. The obtained data sets were statistically analyzed using univariate and multivariate statistical analyses. The Principal Component Analysis (PCA) was used to check systems' stability and possible outliers, whereas Partial Least Squares Discriminant Analysis (PLS-DA) was performed for evaluation of quality of the model as well as its predictive ability using statistically significant metabolites. The subsequent identification of selected metabolites using NIST library and commonly available databases allows for creation of a list of putative biomarkers and related biochemical pathways they are involved in. The selected pathways, like urea and tricarboxylic acid cycle, amino acid and purine metabolism, can play crucial role in pathogenesis of prostate cancer disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Identification and quantification of cardiac glycosides in blood and urine samples by HPLC/MS/MS.

    PubMed

    Guan, F; Ishii, A; Seno, H; Watanabe-Suzuki, K; Kumazawa, T; Suzuki, O

    1999-09-15

    Cardiac glycosides (CG) are of forensic importance because of their toxicity and the fact that very limited methods are available for identification of CG in biological samples. In this study, we have developed an identification and quantification method for digoxin, digitoxin, deslanoside, digoxigenin, and digitoxigenin by high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). CG formed abundant [M + NH4]+ ions and much less abundant [M + H]+ ions as observed with electrospray ionization (ESI) source and ammonium formate buffer. Under mild conditions for collision-induced dissociation (CID), each [M + NH4]+ ion fragmented to produce a dominant daughter ion, which was essential to the sensitive method of selected reaction monitoring (SRM) quantification of CG achieved in this study. SRM was compared with selected ion monitoring (SIM) regarding the effects of sample matrixes on the methodology. SRM produced lower detection limits with biological samples than SIM, while both methods produced equal detection limits with CG standards. On the basis of the HPLC/MS/MS results for CG, we have proposed some generalized points for conducting sensitive SRM measurements, in view of the property of analytes as well as instrumental conditions such as the type of HPLC/MS interface and CID parameters. Analytes of which the molecular ion can produce one abundant daughter ion with high yield under CID conditions may be sensitively measured by SRM. ESI is the most soft ionization source developed so far and can afford formation of the fragile molecular ions that are necessary for sensitive SRM detection. Mild CID conditions such as low collision energy and low pressure of collision gas favor production of an abundant daughter ion that is essential to sensitive SRM detection. This knowledge may provide some guidelines for conducting sensitive SRM measurements of very low concentrations of drugs or toxicants in biological samples.

  11. Comparison of HPLC/ESI-FTICR MS Versus MALDI-TOF/TOF MS for Glycopeptide Analysis of a Highly Glycosylated HIV Envelope Glycoprotein

    PubMed Central

    Irungu, Janet; Go, Eden P.; Zhang, Ying; Dalpathado, Dilusha S.; Liao, Hua-Xin; Haynes, Barton F.; Desaire, Heather

    2013-01-01

    Defining the structures and locations of the glycans attached on secreted proteins and virus envelope proteins is important in understanding how glycosylation affects their biological properties. Glycopeptide mass spectrometry (MS)-based analysis is a very powerful, emerging approach to characterize glycoproteins, in which glycosylation sites and the corresponding glycan structures are elucidated in a single MS experiment. However, to date there is not a consensus regarding which mass spectrometric platform provides the best glycosylation coverage information. Herein, we employ two of the most widely used MS approaches, online high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC/ESI-MS) and offline HPLC followed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), to determine which of the two approaches provides the best glycosylation coverage information of a complex glycoprotein, the group M consensus HIV-1 envelope, CON-S gp140ΔCFI, which has 31 potential glycosylation sites. Our results highlight differences in the informational content obtained between the two methods such as the overall number of glycosylation sites detected, the numbers of N-linked glycans present at each site, and the type of confirmatory information obtained about the glycopeptide using MS/MS experiments. The two approaches are quite complementary, both in their coverage of glycopeptides and in the information they provide in MS/MS experiments. The information in this study contributes to the field of mass spectrometry by demonstrating the strengths and limitations of two widely used MS platforms in glycoprotein analysis. PMID:18565761

  12. Application of LC-MS/MS MRM to Determine Staphylococcal Enterotoxins (SEB and SEA) in Milk.

    PubMed

    Andjelkovic, Mirjana; Tsilia, Varvara; Rajkovic, Andreja; De Cremer, Koen; Van Loco, Joris

    2016-04-20

    Staphylococcus aureus is one of the important aetiological agents of food intoxications in Europe and can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Due to their stability and ease of production and dissemination, some SEs have also been studied as potential agents for bioterrorism. Therefore, specific and accurate analytical tools are required to detect and quantify SEs. Online solid-phase extraction liquid chromatography electrospray ionization tandem mass spectrometry (online SPE-LC-ESI-MS/MS) based on multiple reaction monitoring (MRM) was used to detect and quantify two types of SE (A and B) spiked in milk and buffer solution. SE extraction and concentration was performed according to the European Screening Method developed by the European Reference Laboratory for Coagulase Positive Staphylococci. Trypsin digests were screened for the presence of SEs using selected proteotypic heavy-labeled peptides as internal standards. SEA and SEB were successfully detected in milk samples using LC-MS/MS in MRM mode. The selected SE peptides were proteotypic for each toxin, allowing the discrimination of SEA and SEB in a single run. The detection limit of SEA and SEB was approximately 8 and 4 ng/g, respectively.

  13. MS205 Minisatellite Diversity in Basques: Evidence for a Pre-Neolithic Component

    PubMed Central

    Alonso, Santos; Armour, John A.L.

    1998-01-01

    A number of studies have suggested that Basques might be a relic of Mesolithic Europeans who escaped much of the homogenization brought about by the Neolithic expansion. In an attempt to add new insights into this hypothesis, MS205 minisatellite diversity has been investigated by Minisatellite Variant Repeat (MVR) analysis in a sample of >100 autochthonous individuals from the Basque Country, along with 24 Castilian (N. Spain) and 23 individuals from the United Kingdom. These populations were examined in the context of the available world database for MS205 alleles. To deduce the similarities among populations, we have applied a phylogenetic approach that takes into account similarity between alleles. The variability of these populations seems to be a subset of the greater and presumably older African diversity, as has been suggested previously for non-Africans. Within non-Africans, Basques seem to cluster with other Northern European populations; however, some apparently Basque-specific alleles can be dated back to post-Aurignacian times, supporting the continuity of some lineages of this population since the Upper Paleolithic period. PMID:9872983

  14. Analysis of coffee for the presence of acrylamide by LC-MS/MS.

    PubMed

    Andrzejewski, Denis; Roach, John A G; Gay, Martha L; Musser, Steven M

    2004-04-07

    A variety of popular instant, ground, and brewed coffees were analyzed using a modified liquid chromatography-tandem mass spectrometry (LC-MS/MS) method specifically developed for the determination of acrylamide in foods. Coffee test portions were spiked with 13C3-labeled acrylamide as an internal standard prior to their extraction and cleanup. Ground coffees (1 g) and instant coffees (0.5 g) were extracted by shaking with 9 mL of water for 20 min. Brewed coffee test portions (9 mL) were taken through the cleanup procedure without further dilution with extraction solvent. Coffee test portions were cleaned up by passing 1.5 mL first through an Oasis HLB (hydrophilic/lipophilic copolymer sorbent) solid phase extraction (SPE) cartridge and then a Bond Elut-Accucat (cation and anion exchange sorbent) SPE cartridge. The cleaned up extracts were analyzed by positive ion electrospray LC-MS/MS. The MS/MS data was used to detect, confirm, and quantitate acrylamide. The limit of quantitation of the method was 10 ng/g for ground and instant coffees and 1.0 ng/mL for brewed coffee. The levels of acrylamide ranged from 45 to 374 ng/g in unbrewed coffee grounds, from 172 to 539 ng/g in instant coffee crystals, and from 6 to 16 ng/mL in brewed coffee.

  15. Characterization of cocoa liquors by GC-MS and LC-MS/MS: focus on alkylpyrazines and flavanols.

    PubMed

    Magi, Emanuele; Bono, Luca; Di Carro, Marina

    2012-09-01

    Flavor is one of the most important characteristics of chocolate products and is due to a complex volatile fraction, depending both on the cocoa bean genotype and the several processes occurring during chocolate production (fermentation, drying, roasting and conching). Alkylpyrazines are among the most studied volatiles, being one of the main classes of odorant compounds in cocoa products. In this work, a mass spectrometric approach was used for the comparison of cocoa liquors from different countries. A headspace solid-phase microextraction gas chromatography-mass spectrometry method was developed for the qualitative study of the volatile fraction; the standard addition method was then used for the quantitative determination of five pyrazines (2-methylpyrazine, 2,3-dimethylpyrazine, 2,5-dimethylpyrazine, 2,3,5-trimethylpyrazine and tetramethylpyrazine). Satisfactory figures of merit were obtained: Limits of quantitation were in the range 0.1-2.7 ng/g; repeatability and reproducibility varied between 3% and 7% and between 8% and 14%, respectively. The total content of the pyrazines was remarkably different in the considered samples, ranging from 99 to 708 ng/g. Tetramethylpyrazine showed the highest concentration in all samples, with a maximum value of 585 ng/g. A preliminary study was also performed on the nonvolatile fraction using LC-MS/MS, identifying some flavanols such as catechin, epicatechin and procyanidins. Copyright © 2012 John Wiley & Sons, Ltd.

  16. UPLC-MS/MS based diagnostics for epithelial ovarian cancer using fully sialylated C4-binding protein.

    PubMed

    Tanabe, Kazuhiro; Matsuo, Koji; Miyazawa, Masaki; Hayashi, Masaru; Ikeda, Masae; Shida, Masako; Hirasawa, Takeshi; Sho, Ryuichiro; Mikami, Mikio

    2018-05-01

    Serum levels of fully sialylated C4-binding protein (FS-C4BP) are remarkably elevated in patients with epithelial ovarian cancer (EOC) and can be used as a marker to distinguish ovarian clear cell carcinoma from endometrioma. This study aimed to develop a stable, robust and reliable liquid chromatography-hybrid mass spectrometry (UPLC-MS/MS) based diagnostic method that would generalize FS-C4BP as a clinical EOC biomarker. Glycopeptides derived from 20 μL of trypsin-digested serum glycoprotein were analyzed via UPLC equipped with an electrospray ionization time-of-flight mass spectrometer. This UPLC-MS/MS-based diagnostic method was optimized for FS-C4BP and validated using sera from 119 patients with EOC and 127 women without cancer. A1958 (C4BP peptide with two fully sialylated biantennary glycans) was selected as a marker of FS-C4BP because its level in serum was highest among FS-C4BP family members. Preparation and UPLC-MS/MS were optimized for A1958, and performance and robustness were significantly improved relative to our previous method. An area under the curve analysis of the FS-C4BP index receiver operating characteristic curve revealed that the ratio between A1958 and A1813 (C4BP peptide with two partially sialylated biantennary glycans) reached 85%. A combination of the FS-C4BP index and carbohydrate antigen-125 levels further enhanced the sensitivity and specificity. © 2017 The Authors. Biomedical Chromatography published by John Wiley & Sons Ltd.

  17. NMR, ESI/MS, and MALDI-TOF/MS analysis of pear juice polymeric proanthocyanidins with potent free radical scavenging activity.

    PubMed

    Es-Safi, Nour-Eddine; Guyot, Sylvain; Ducrot, Paul-Henri

    2006-09-20

    The structure of a polymeric proanthocyanidin fraction isolated from pear juice was characterized by NMR, ESI/MS, and MALDI-TOF/MS analyses, and its antioxidant activity was investigated using the DPPH free radical scavenging method. The results obtained from 13C NMR analysis showed the predominance of signals representative of procyanidins. Typical signals in the chemical shift region between 70 and 90 ppm demonstrated the exclusive presence of epicatechin units. The results obtained through negative ESI/MS analysis showed singly and doubly charged ions corresponding to the molecular mass of procyanidins with a degree of polymerization up to 22. The spectra obtained through MALDI-TOF/MS analysis revealed the presence of two series of tannin oligomers. Supporting the observations from NMR spectroscopy, the first series consists of well-resolved tannin identified as procyanidin polymers units with chain lengths of up to 25. A second series of monogalloyl flavan-3-ols polymers with polymerization degree up to 25 were also detected. This is the first mass spectrometric evidence confirming the existence of galloylated procyanidin oligomers in pear fruits. Within each of these oligomers, various signals exist suggesting the presence of several oligomeric tannins. The antioxidant properties of the polymeric fraction were investigated through reduction of the DPPH free radical, and the results obtained showed that the polymeric fraction exhibited a higher antioxidant power compared to those of (+)-catechin and B3 procyanidin dimer.

  18. Screening for anabolic steroids in urine of forensic cases using fully automated solid phase extraction and LC-MS-MS.

    PubMed

    Andersen, David W; Linnet, Kristian

    2014-01-01

    A screening method for 18 frequently measured exogenous anabolic steroids and the testosterone/epitestosterone (T/E) ratio in forensic cases has been developed and validated. The method involves a fully automated sample preparation including enzyme treatment, addition of internal standards and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forensic cases were analyzed to determine the T/E ratio and occurrence of exogenous anabolic steroids. Extraction recoveries ranged from 77 to 95%, matrix effects from 48 to 78%, overall process efficiencies from 40 to 54% and the lower limit of identification ranged from 2 to 40 ng/mL. In the 580 urine samples analyzed from routine forensic cases, 17 (2.9%) were found positive for one or more anabolic steroids. Only seven different steroids including testosterone were found in the material, suggesting that only a small number of common steroids are likely to occur in a forensic context. The steroids were often in high concentrations (>100 ng/mL), and a combination of steroids and/or other drugs of abuse were seen in the majority of cases. The method presented serves as a fast and automated screening procedure, proving the suitability of LC-MS-MS for analyzing anabolic steroids. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Phase-0/microdosing studies using PET, AMS, and LC-MS/MS: a range of study methodologies and conduct considerations. Accelerating development of novel pharmaceuticals through safe testing in humans - a practical guide.

    PubMed

    Burt, Tal; John, Christy S; Ruckle, Jon L; Vuong, Le T

    2017-05-01

    Phase-0 studies, including microdosing, also called Exploratory Investigational New Drug (eIND) or exploratory clinical trials, are a regulatory framework for first-in-human (FIH) trials. Common to these approaches is the use and implied safety of limited exposures to test articles. Use of sub-pharmacological doses in phase-0/microdose studies requires sensitive analytic tools such as accelerator mass spectrometer (AMS), Positron Emission Tomography (PET), and Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) to determine drug disposition. Areas covered: Here we present a practical guide to the range of methodologies, design options, and conduct strategies that can be used to increase the efficiency of drug development. We provide detailed examples of relevant developmental scenarios. Expert opinion: Validation studies over the past decade demonstrated the reliability of extrapolation of sub-pharmacological to therapeutic-level exposures in more than 80% of cases, an improvement over traditional allometric approaches. Applications of phase-0/microdosing approaches include study of pharmacokinetic and pharmacodynamic properties, target tissue localization, drug-drug interactions, effects in vulnerable populations (e.g. pediatric), and intra-target microdosing (ITM). Study design should take into account the advantages and disadvantages of each analytic tool. Utilization of combinations of these analytic techniques increases the versatility of study designs and the power of data obtained.

  20. High-throughput quantitation of amino acids in rat and mouse biological matrices using stable isotope labeling and UPLC-MS/MS analysis.

    PubMed

    Takach, Edward; O'Shea, Thomas; Liu, Hanlan

    2014-08-01

    Quantifying amino acids in biological matrices is typically performed using liquid chromatography (LC) coupled with fluorescent detection (FLD), requiring both derivatization and complete baseline separation of all amino acids. Due to its high specificity and sensitivity, the use of UPLC-MS/MS eliminates the derivatization step and allows for overlapping amino acid retention times thereby shortening the analysis time. Furthermore, combining UPLC-MS/MS with stable isotope labeling (e.g., isobaric tag for relative and absolute quantitation, i.e., iTRAQ) of amino acids enables quantitation while maintaining sensitivity, selectivity and speed of analysis. In this study, we report combining UPLC-MS/MS analysis with iTRAQ labeling of amino acids resulting in the elution and quantitation of 44 amino acids within 5 min demonstrating the speed and convenience of this assay over established approaches. This chromatographic analysis time represented a 5-fold improvement over the conventional HPLC-MS/MS method developed in our laboratory. In addition, the UPLC-MS/MS method demonstrated improvements in both specificity and sensitivity without loss of precision. In comparing UPLC-MS/MS and HPLC-MS/MS results of 32 detected amino acids, only 2 amino acids exhibited imprecision (RSD) >15% using UPLC-MS/MS, while 9 amino acids exhibited RSD >15% using HPLC-MS/MS. Evaluating intra- and inter-assay precision over 3 days, the quantitation range for 32 detected amino acids in rat plasma was 0.90-497 μM, with overall mean intra-day precision of less than 15% and mean inter-day precision of 12%. This UPLC-MS/MS assay was successfully implemented for the quantitative analysis of amino acids in rat and mouse plasma, along with mouse urine and tissue samples, resulting in the following concentration ranges: 0.98-431 μM in mouse plasma for 32 detected amino acids; 0.62-443 μM in rat plasma for 32 detected amino acids; 0.44-8590μM in mouse liver for 33 detected amino acids; 0.61-1241

  1. IL2RA/CD25 Gene Polymorphisms: Uneven Association with Multiple Sclerosis (MS) and Type 1 Diabetes (T1D)

    PubMed Central

    Alcina, Antonio; Fedetz, María; Ndagire, Dorothy; Fernández, Oscar; Leyva, Laura; Guerrero, Miguel; Abad-Grau, María M.; Arnal, Carmen; Delgado, Concepción; Lucas, Miguel; Izquierdo, Guillermo; Matesanz, Fuencisla

    2009-01-01

    Background IL-2 receptor (IL2R) alpha is the specific component of the high affinity IL2R system involved in the immune response and in the control of autoimmunity. Methods and Results Here we perform a replication and fine mapping of the IL2RA gene region analyzing 3 SNPs previously associated with multiple sclerosis (MS) and 5 SNPs associated with type 1 diabetes (T1D) in a collection of 798 MS patients and 927 matched Caucasian controls from the south of Spain. We observed association with MS in 6 of 8 SNPs. The rs1570538, at the 3′- UTR extreme of the gene, previously reported to have a weak association with MS, is replicated here (P = 0.032). The most associated T1D SNP (rs41295061) was not associated with MS in the present study. However, the rs35285258, belonging to another independent group of SNPs associated with T1D, showed the maximal association in this study but different risk allele. We replicated the association of only one (rs2104286) of the two IL2RA SNPs identified in the recently performed genome-wide association study of MS. Conclusions These findings confirm and extend the association of this gene with MS and reveal a genetic heterogeneity of the associated polymorphisms and risk alleles between MS and T1D suggesting different immunopathological roles of IL2RA in these two diseases. PMID:19125193

  2. LC-ESI-MS/MS and cytotoxic activity of three Pistacia species.

    PubMed

    Kirollos, F N; Elhawary, S S; Salama, O M; Elkhawas, Y A

    2018-01-28

    LC-ESI-MS/MS was used for a comprehensive characterisation of ethanol extract from the leaves of three Pistacia species. After optimisation of the method and the use of the negative ionisation mode, a total of 42 different compounds were identified, of which 22 were tentatively characterised in P. chinensis Bunge, 33 in P. khinjuk stocks and 25 in P. lentiscus L. leaves. Flavonoids, phenolic acids, and their derivatives were the most abundant identified compounds. LC-ESI-MS/MS revealed identification of 15, 18 and 6 not previously detected compounds in P. chinensis Bunge, P. khinjuk Stocks and P. lentiscus L., respectively. The three extracts were also tested for their cytotoxic activities against human PC3 prostate cancer, A549 lung cancer, MCF7 breast cancer and HepG2 liver cancer. Generally, all the extracts have a moderate cytotoxic activity against lung, breast and prostate cancer, with different IC 50 . However, only P. lentiscus L. showed moderate activity against liver cancer.

  3. CCHCR1 interacts with EDC4, suggesting its localization in P-bodies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ling, Y.H.; Wong, C.C.; Li, K.W.

    2014-09-10

    Coiled‐coil alpha‐helical rod protein 1 (CCHCR1) is suggested as a candidate biomarker for psoriasis for more than a decade but its function remains poorly understood because of the inconsistent findings in the literature. CCHCR1 protein is suggested to be localized in the cytoplasm, nucleus, mitochondria, or centrosome and to regulate various cellular functions, including steroidogenesis, proliferation, differentiation, and cytoskeleton organization. In this study, we attempted to find a consensus between these findings by identifying the interaction partners of CCHCR1 using co-immunoprecipiation with a stable cell line expressing EGFP-tagged CCHCR1. Out of more than 100 co-immunoprecipitants identified by liquid chromatography-tandem massmore » spectrometry (LC-MS/MS), the enhancer of mRNA-decapping protein 4 (EDC4), which is a processing body (P-body) component, was particularly found to be the major interacting partner of CCHCR1. Confocal imaging confirmed the localization of CCHCR1 in P-bodies and its N-terminus is required for this subcellular localization, suggesting that CCHCR1 is a novel P-body component. As P-bodies are the site for mRNA metabolism, our findings provide a molecular basis for the function of CCHCR1, any disruption of which may affect the transcriptome of the cell, and causing abnormal cell functions. - Highlights: • We identified CCHCR1 as a novel P-body component. • We identified EDC4 as the major interacting partner of CCHCR1. • N-terminus of CCHCR1 protein is required for its P-bodies localization.« less

  4. Improved LC-MS/MS method for the quantification of hepcidin-25 in clinical samples.

    PubMed

    Abbas, Ioana M; Hoffmann, Holger; Montes-Bayón, María; Weller, Michael G

    2018-06-01

    Mass spectrometry-based methods play a crucial role in the quantification of the main iron metabolism regulator hepcidin by singling out the bioactive 25-residue peptide from the other naturally occurring N-truncated isoforms (hepcidin-20, -22, -24), which seem to be inactive in iron homeostasis. However, several difficulties arise in the MS analysis of hepcidin due to the "sticky" character of the peptide and the lack of suitable standards. Here, we propose the use of amino- and fluoro-silanized autosampler vials to reduce hepcidin interaction to laboratory glassware surfaces after testing several types of vials for the preparation of stock solutions and serum samples for isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS). Furthermore, we have investigated two sample preparation strategies and two chromatographic separation conditions with the aim of developing a LC-MS/MS method for the sensitive and reliable quantification of hepcidin-25 in serum samples. A chromatographic separation based on usual acidic mobile phases was compared with a novel approach involving the separation of hepcidin-25 with solvents at high pH containing 0.1% of ammonia. Both methods were applied to clinical samples in an intra-laboratory comparison of two LC-MS/MS methods using the same hepcidin-25 calibrators with good correlation of the results. Finally, we recommend a LC-MS/MS-based quantification method with a dynamic range of 0.5-40 μg/L for the assessment of hepcidin-25 in human serum that uses TFA-based mobile phases and silanized glass vials. Graphical abstract Structure of hepcidin-25 (Protein Data Bank, PDB ID 2KEF).

  5. Quantitative interference by cysteine and N-acetylcysteine metabolites during the LC-MS/MS bioanalysis of a small molecule.

    PubMed

    Barricklow, Jason; Ryder, Tim F; Furlong, Michael T

    2009-08-01

    During LC-MS/MS quantification of a small molecule in human urine samples from a clinical study, an unexpected peak was observed to nearly co-elute with the analyte of interest in many study samples. Improved chromatographic resolution revealed the presence of at least 3 non-analyte peaks, which were identified as cysteine metabolites and N-acetyl (mercapturic acid) derivatives thereof. These metabolites produced artifact responses in the parent compound MRM channel due to decomposition in the ionization source of the mass spectrometer. Quantitative comparison of the analyte concentrations in study samples using the original chromatographic method and the improved chromatographic separation method demonstrated that the original method substantially over-estimated the analyte concentration in many cases. The substitution of electrospray ionization (ESI) for atmospheric pressure chemical ionization (APCI) nearly eliminated the source instability of these metabolites, which would have mitigated their interference in the quantification of the analyte, even without chromatographic separation. These results 1) demonstrate the potential for thiol metabolite interferences during the quantification of small molecules in pharmacokinetic samples, and 2) underscore the need to carefully evaluate LC-MS/MS methods for molecules that can undergo metabolism to thiol adducts to ensure that they are not susceptible to such interferences during quantification.

  6. Multi-mycotoxin analysis of animal feed and animal-derived food using LC-MS/MS system with timed and highly selective reaction monitoring.

    PubMed

    Zhao, Zhiyong; Liu, Na; Yang, Lingchen; Deng, Yifeng; Wang, Jianhua; Song, Suquan; Lin, Shanhai; Wu, Aibo; Zhou, Zhenlei; Hou, Jiafa

    2015-09-01

    Mycotoxins have the potential to enter the human food chain through carry-over of contaminants from feed into animal-derived products. The objective of the study was to develop a reliable and sensitive method for the analysis of 30 mycotoxins in animal feed and animal-derived food (meat, edible animal tissues, and milk) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the study, three extraction procedures, as well as various cleanup procedures, were evaluated to select the most suitable sample preparation procedure for different sample matrices. In addition, timed and highly selective reaction monitoring on LC-MS/MS was used to filter out isobaric matrix interferences. The performance characteristics (linearity, sensitivity, recovery, precision, and specificity) of the method were determined according to Commission Decision 2002/657/EC and 401/2006/EC. The established method was successfully applied to screening of mycotoxins in animal feed and animal-derived food. The results indicated that mycotoxin contamination in feed directly influenced the presence of mycotoxin in animal-derived food. Graphical abstract Multi-mycotoxin analysis of animal feed and animal-derived food using LC-MS/MS.

  7. MS/MS fragmentation-guided search of TMG-chitooligomycins and their structure-activity relationship in specific β-N-acetylglucosaminidase inhibition.

    PubMed

    Usuki, Hirokazu; Yamamoto, Yukihiro; Kumagai, Yuya; Nitoda, Teruhiko; Kanzaki, Hiroshi; Hatanaka, Tadashi

    2011-04-21

    The reducing tetrasaccharide TMG-chitotriomycin (1) is an inhibitor of β-N-acetylglucosaminidase (GlcNAcase), produced by the actinomycete Streptomyces anulatus NBRC13369. The inhibitor shows a unique inhibitory spectrum, that is, selectivity toward enzymes from chitin-containing organisms such as insects and fungi. Nevertheless, its structure-selectivity relationship remains to be clarified. In this study, we conducted a structure-guided search of analogues of 1 in order to obtain diverse N,N,N-trimethylglucosaminium (TMG)-containing chitooligosaccharides. In this approach, the specific fragmentation profile of 1 on ESI-MS/MS analysis was used for the selective detection of desired compounds. As a result, two new analogues, named TMG-chitomonomycin (3) and TMG-chitobiomycin (2), were obtained from a culture filtrate of 1-producing Streptomyces. Their enzyme-inhibiting activity revealed that the potency and selectivity depended on the degree of polymerization of the reducing end GlcNAc units. Furthermore, a computational modeling study inspired the inhibitory mechanism of TMG-related compounds as a mimic of the substrate in the Michaelis complex of the GH20 enzyme. This study is an example of the successful application of a MS/MS experiment for structure-guided isolation of natural products.

  8. Identification of chemical markers in Cordyceps sinensis by HPLC-MS/MS.

    PubMed

    Hu, Hankun; Xiao, Ling; Zheng, Baogen; Wei, Xin; Ellis, Alexis; Liu, Yi-Ming

    2015-10-01

    Authentication and quality assessment of Cordyceps sinensis, a precious and pricey natural product that offers a variety of health benefits, is highly significant. To identify effective chemical markers, authentic C. sinensis was thoroughly screened by using HPLC-MS/MS. In addition to many previously reported ingredients, two glycosides, i.e., cyclo-Ala-Leu-rhamnose and Phe-o-glucose, were detected for the first time in this material. Six ingredients detected, including cordycepin, D-mannitol, Phe, Phe-o-glucose, cyclo-Gly-Pro, and cyclo-Ala-Leu-rhamnose, were selected as a collection of chemical markers. An HPLC-MS/MS method was developed to simultaneously quantify them with sensitivity and specificity. The method had limits of detection ranging from 0.008 μg mL(-1) for cordycepin to 0.75 μg mL(-1) for cyclo-Gly-Pro. Recovery was found between 96 and 103 % in all tests. To evaluate the effectiveness of the marker collection proposed, five authentic C. sinensis samples and five samples of its substitutes were analyzed. Cordycepin, D-mannitol, and Phe were found present in all samples. The contents ranged from 0.0076 to 0.029 % (w/w) for cordycepin, 0.33 to 18.9 % for mannitol, and 0.0013 to 0.642 % for Phe. Interestingly, the two glycosides, Phe-o-glucose and cyclo-Ala-Leu-rhamnose, were detected only in authentic C. sinensis samples. These results indicated that the proposed protocol based on HPLC-MS/MS quantification of the markers might have a great potential in authentication and quality assessment of C. sinensis. Graphical abstract Chemical markers of C. sinensis identified in this work.

  9. [Development of UPLC-Q-TOF-MS/MS combined with reference herb approach to rapidly screen commercial sulfur-fumigated ginseng].

    PubMed

    Zhou, Shan-Shan; Xu, Jin-Di; Shen, Hong; Liu, Huan-Huan; Li, Song-Lin

    2014-08-01

    An ultra-performance liquid chromatography-quadrupole/time of flight mass spectrometry (UPLC-Q-TOF-MS/MS) combined with reference herb method was developed to rapidly screen commercial sulfur-fumigated ginseng. Sufur-fumigated ginseng reference herb was prepared using genuine ginseng by conventional procedure. Then the reference sulfur-fumigated ginseng sample was analyzed by UPLC-Q-TOF-MS/MS to identify characteristic marker components. 25-hydroxyl-Re sulfate with higher abundance was se- lected as marker compound from 8 characteristic components identified in sulfur-fumigated ginseng reference herb. The fragmentation of 25-hydroxyl-Re sulfate was extensively investigated, fragment ion m/z 879.44 with higher intensity was chosen as the characteristic ion of sulfur-fumigated ginseng. The response of ion m/z 879. 44 was improved by optimizing the MS conditions so that this ion could be used as the characteristic marker ion for screening purpose in ion extracting screening mode. The established approach was successfully applied to inspect 21 commercial ginseng samples collected from different cities in China It was found that the chemical profiles of 9 samples were similar to that of sulfur-fumigated ginseng reference herb, and the characteristic ion m/z 879. 44 of 25-hydroxyl-Re sulfate was also detected in these samples, suggesting that there were nearly 43% ginseng samples analyzed being sulfur-fumigated. This findng agreed well with the results of sulfur dioxide residues of these 21 commercial ginseng samples determined with the method documented in Chinese Pharmacopeia Compared with the method documented in Chinese Pharmacopeia, the proposed approach is more rapid and specific for screening sulfur-fumigated ginseng. SFDA of China should strengthen the enforcement to prohibit ginseng being sulfur-fumigated, so that ginseng and it preparations could be effectively and safely benefit to the health of human beings.

  10. Can we trust mass spectrometry for determination of arsenic peptides in plants: comparison of LC-ICP-MS and LC-ES-MS/ICP-MS with XANES/EXAFS in analysis of Thunbergia alata.

    PubMed

    Bluemlein, Katharina; Raab, Andrea; Meharg, Andrew A; Charnock, John M; Feldmann, Jörg

    2008-04-01

    The weakest step in the analytical procedure for speciation analysis is extraction from a biological material into an aqueous solution which undergoes HPLC separation and then simultaneous online detection by elemental and molecular mass spectrometry (ICP-MS/ES-MS). This paper describes a study to determine the speciation of arsenic and, in particular, the arsenite phytochelatin complexes in the root from an ornamental garden plant Thunbergia alata exposed to 1 mg As L(-1) as arsenate. The approach of formic acid extraction followed by HPLC-ES-MS/ICP-MS identified different As(III)-PC complexes in the extract of this plant and made their quantification via sulfur (m/z 32) and arsenic (m/z 75) possible. Although sulfur sensitivity could be significantly increased when xenon was used as collision gas in ICP-qMS, or when HR-ICP-MS was used in medium resolution, the As:S ratio gave misleading results in the identification of As(III)-PC complexes due to the relatively low resolution of the chromatography system in relation to the variety of As-peptides in plants. Hence only the parallel use of ES-MS/ICP-MS was able to prove the occurrence of such arsenite phytochelatin complexes. Between 55 and 64% of the arsenic was bound to the sulfur of peptides mainly as As(III)(PC(2))(2), As(III)(PC(3)) and As(III)(PC(4)). XANES (X-ray absorption near-edge spectroscopy) measurement, using the freshly exposed plant root directly, confirmed that most of the arsenic is trivalent and binds to S of peptides (53% As-S) while 38% occurred as arsenite and only 9% unchanged as arsenate. EXAFS data confirmed that As-S and As-O bonds occur in the plants. This study confirms, for the first time, that As-peptides can be extracted by formic acid and chromatographically separated on a reversed-phase column without significant decomposition or de-novo synthesis during the extraction step.

  11. UP-HILIC-MS/MS to Determine the Action Pattern of Penicillium sp. Dextranase.

    PubMed

    Yi, Lin; Sun, Xue; Du, Kenze; Ouyang, Yilan; Wu, Chengling; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

    2015-07-01

    Investigation of the action pattern of enzymes acting on carbohydrates is challenging, as both the substrate and the digestion products are complex mixtures. Dextran and its enzyme-derived oligosaccharides are widely used for many industrial applications. In this work, a new method relying on ultra-performance hydrophilic interaction liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UP-HILIC-Q/TOF-MS/MS) was developed to analyze a complex mixture of dextran oligosaccharide products to determine the action pattern of dextranase. No derivatization of oligosaccharides was required and the impact of the α- and β-configurations of the native oligosaccharides on the chromatographic separation was eliminated. The 1→6, 1→3, 1→4 backbone linkages and the branch linkages of these oligosaccharides were all distinguished from diagnostic ions in their MS/MS spectra, including fragments corresponding to (0,2)A, (0,3)A, (0,4)A, B-H2O, (2,5)A, and (3,5)A. The sequences of the oligosaccharide products were similarly established. Thus, the complex oligosaccharide mixtures in dextran digestion products were profiled and identified using this method. The more enzyme-resistant structures in dextran were established using much less sample, labor, time, and uncertainty than in previous studies. This method provides an efficient, sensitive, and straightforward way to monitor the entire process of digestion, establish the action pattern of the dextranase from Penicillium sp., and to support the proper industrial application of dextranase.

  12. UP-HILIC-MS/MS to Determine the Action Pattern of Penicillium sp. Dextranase

    NASA Astrophysics Data System (ADS)

    Yi, Lin; Sun, Xue; Du, Kenze; Ouyang, Yilan; Wu, Chengling; Xu, Naiyu; Linhardt, Robert J.; Zhang, Zhenqing

    2015-07-01

    Investigation of the action pattern of enzymes acting on carbohydrates is challenging, as both the substrate and the digestion products are complex mixtures. Dextran and its enzyme-derived oligosaccharides are widely used for many industrial applications. In this work, a new method relying on ultra-performance hydrophilic interaction liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UP-HILIC- Q/TOF-MS/MS) was developed to analyze a complex mixture of dextran oligosaccharide products to determine the action pattern of dextranase. No derivatization of oligosaccharides was required and the impact of the α- and β-configurations of the native oligosaccharides on the chromatographic separation was eliminated. The 1→6, 1→3, 1→4 backbone linkages and the branch linkages of these oligosaccharides were all distinguished from diagnostic ions in their MS/MS spectra, including fragments corresponding to 0,2A, 0,3A, 0,4A, B-H2O, 2,5A, and 3,5A. The sequences of the oligosaccharide products were similarly established. Thus, the complex oligosaccharide mixtures in dextran digestion products were profiled and identified using this method. The more enzyme-resistant structures in dextran were established using much less sample, labor, time, and uncertainty than in previous studies. This method provides an efficient, sensitive, and straightforward way to monitor the entire process of digestion, establish the action pattern of the dextranase from Penicillium sp., and to support the proper industrial application of dextranase.

  13. Absolute quantification of histone PTM marks by MRM-based LC-MS/MS.

    PubMed

    Gao, Jun; Liao, Rijing; Yu, Yanyan; Zhai, Huili; Wang, Yingqi; Sack, Ragna; Peters, Antoine H F M; Chen, Jiajia; Wu, Haiping; Huang, Zheng; Hu, Min; Qi, Wei; Lu, Chris; Atadja, Peter; Oyang, Counde; Li, En; Yi, Wei; Zhou, Shaolian

    2014-10-07

    The N-terminal tails of core histones harbor the sites of numerous post-translational modifications (PTMs) with important roles in the regulation of chromatin structure and function. Profiling histone PTM marks provides data that help understand the epigenetics events in cells and their connections with cancer and other diseases. Our previous study demonstrated that specific derivatization of histone peptides by NHS propionate significantly improved their chromatographic performance on reversed phase columns for LC/MS analysis. As a step forward, we recently developed a multiple reaction monitoring (MRM) based LC-MS/MS method to analyze 42 targeted histone peptides. By using stable isotopic labeled peptides as internal standards that are spiked into the reconstituted solutions, this method allows to measure absolute concentration of the tryptic peptides of H3 histone proteins extracted from cancer cell lines. The method was thoroughly validated for the accuracy and reproducibility through analyzing recombinant histone proteins and cellular samples. The linear dynamic range of the MRM assays was achieved in 3 orders of magnitude from 1 nM to 1 μM for all targeted peptides. Excellent intrabatch and interbatch reproducibility (<15% CV) was obtained. This method has been used to study translocated NSD2 (a histone lysine methyltransferase that catalyzes the histone lysine 36 methylation) function with its overexpression in KMS11 multiple myeloma cells. From the results we have successfully quantitated both individual and combinatorial histone marks in parental and NSD2 selective knockout KMS11 cells.

  14. Preprocessing and Analysis of LC-MS-Based Proteomic Data

    PubMed Central

    Tsai, Tsung-Heng; Wang, Minkun; Ressom, Habtom W.

    2016-01-01

    Liquid chromatography coupled with mass spectrometry (LC-MS) has been widely used for profiling protein expression levels. This chapter is focused on LC-MS data preprocessing, which is a crucial step in the analysis of LC-MS based proteomics. We provide a high-level overview, highlight associated challenges, and present a step-by-step example for analysis of data from LC-MS based untargeted proteomic study. Furthermore, key procedures and relevant issues with the subsequent analysis by multiple reaction monitoring (MRM) are discussed. PMID:26519169

  15. XVI European Charcot Foundation Lecture: Nutrition and environment, can MS be prevented?

    PubMed Central

    Simon, Kelly Claire; Munger, Kassandra L; Ascherio, Alberto

    2012-01-01

    Multiple sclerosis is a relatively common debilitating neurologic disease that affects people in early adulthood. While the characteristic pathology of MS has been well described, the etiology of the disease is not well understood, despite decades of research and the identification of strong genetic and environmental candidates for susceptibility. A question central to all diseases, but posed specifically for MS at the XVI European Charcot Foundation Lecture, was ‘Can MS be prevented?’ To address this question, we have evaluated the available data regarding nutritional and environmental factors that may be related to MS susceptibility and suggest the extent to which a potential intervention may reduce disease burden. It is our opinion that intervention, particularly supplementation with vitamin D, could have a dramatic impact on disease prevalence. Understanding that any intervention or behavioral modification will surely act in the context of genetic susceptibility and unidentified stochastic events, it is likely that not all MS is ‘preventable’. Epidemiologic observation has provided key insights into environmental and nutritional factors that may alter one’s susceptibility to MS, however, there are still many questions in unraveling the etiology of this complex disease. PMID:21975017

  16. Misleading measures in Vitamin D analysis: a novel LC-MS/MS assay to account for epimers and isobars.

    PubMed

    Shah, Iltaf; James, Ricky; Barker, James; Petroczi, Andrea; Naughton, Declan P

    2011-05-14

    Recently, the accuracies of many commercially available immunoassays for Vitamin D have been questioned. Liquid chromatography tandem mass spectrometry (LC- MS/MS) has been shown to facilitate accurate separation and quantification of the major circulating metabolite 25-hydroxyvitamin-D3 (25OHD3) and 25-hydroxyvitamin-D2 (25OHD2) collectively termed as 25OHD. However, among other interferents, this method may be compromised by overlapping peaks and identical masses of epimers and isobars, resulting in inaccuracies in circulating 25OHD measurements. The aim of this study was to develop a novel LC-MS/MS method that can accurately identify and quantitate 25OHD3 and 25OHD2 through chromatographic separation of 25OHD from its epimers and isobars. A positive ion electrospray ionisation (ESI) LC-MS/MS method was used in the Multiple Reaction Monitoring (MRM) mode for quantification. It involved i) liquid-liquid extraction, ii) tandem columns (a high resolution ZORBAX C18 coupled to an ULTRON chiral, with guard column and inlet filter), iii) Stanozolol-D3 as internal standard, and iv) identification via ESI and monitoring of three fragmentation transitions. To demonstrate the practical usefulness of our method, blood samples were collected from 5 healthy male Caucasian volunteers; age range 22 to 37 years and 25OHD2, 25OHD3 along with co-eluting epimers and analogues were quantified. The new method allowed chromatographic separation and quantification of 25OHD2, 25OHD3, along with 25OHD3 epimer 3-epi-25OHD3 and isobars 1-α-hydroxyvitamin-D3 (1αOHD3), and 7-α-hydroxy-4-cholesten-3-one (7αC4). The new assay was capable of detecting 0.25 ng/mL of all analytes in serum. To our knowledge, this is the first specific, reliable, reproducible and robust LC-MS/MS method developed for the accurate detection of 25OHD (Vitamin D). The method is capable of detecting low levels of 25OHD3 and 25OHD2 together with chromatographic separation from the co-eluting epimers and isobars and

  17. Development and validation of a UPLC-MS/MS method for quantitation of droxidopa in human plasma: Application to a pharmacokinetic study.

    PubMed

    Wang, Haidong; Yang, Guangsheng; Zhou, Jinyu; Pei, Jiang; Zhang, Qiangfeng; Song, Xingfa; Sun, Zengxian

    2016-08-01

    In this study, a simple and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for quantitation of droxidopa in human plasma for the first time. A simple plasma protein precipitation method using methanol containing 3% formic acid was selected, and the separation was achieved by an Acquity UPLC™ BEH Amide column (2.1mm×50mm, 1.7μm) with a gradient elution using acetonitrile, ammonium formate buffer and formic acid as mobile phase. The detection of droxidopa and benserazide (internal standard, IS) was performed using positive-ion electrospray tandem mass spectrometry via multiple reaction monitoring (MRM). The precursor-to-product ion transitions m/z 214.2→m/z 152.0 for droxidopa, and m/z 258.1→m/z 139.1 for IS were used for quantification. A lower limit of quantification of 5.00ng/mL was achieved and the linear curve range was 5.00-4000ng/mL using a weighted (1/x(2)) linear regression model. Intra-assay and inter-assay precision was less than 10.2%, and the accuracy ranged from 0.1% to 2.1%. Stability, recovery and matrix effects were within the acceptance criteria recommended by the regulatory bioanalytical guidelines. The method was successfully applied to a pharmacokinetic study of droxidopa in healthy Chinese volunteers. Copyright © 2016. Published by Elsevier B.V.

  18. OpenKnowledge for peer-to-peer experimentation in protein identification by MS/MS

    PubMed Central

    2011-01-01

    Background Traditional scientific workflow platforms usually run individual experiments with little evaluation and analysis of performance as required by automated experimentation in which scientists are being allowed to access numerous applicable workflows rather than being committed to a single one. Experimental protocols and data under a peer-to-peer environment could potentially be shared freely without any single point of authority to dictate how experiments should be run. In such environment it is necessary to have mechanisms by which each individual scientist (peer) can assess, locally, how he or she wants to be involved with others in experiments. This study aims to implement and demonstrate simple peer ranking under the OpenKnowledge peer-to-peer infrastructure by both simulated and real-world bioinformatics experiments involving multi-agent interactions. Methods A simulated experiment environment with a peer ranking capability was specified by the Lightweight Coordination Calculus (LCC) and automatically executed under the OpenKnowledge infrastructure. The peers such as MS/MS protein identification services (including web-enabled and independent programs) were made accessible as OpenKnowledge Components (OKCs) for automated execution as peers in the experiments. The performance of the peers in these automated experiments was monitored and evaluated by simple peer ranking algorithms. Results Peer ranking experiments with simulated peers exhibited characteristic behaviours, e.g., power law effect (a few dominant peers dominate), similar to that observed in the traditional Web. Real-world experiments were run using an interaction model in LCC involving two different types of MS/MS protein identification peers, viz., peptide fragment fingerprinting (PFF) and de novo sequencing with another peer ranking algorithm simply based on counting the successful and failed runs. This study demonstrated a novel integration and useful evaluation of specific proteomic

  19. Do author-suggested reviewers rate submissions more favorably than editor-suggested reviewers? A study on atmospheric chemistry and physics.

    PubMed

    Bornmann, Lutz; Daniel, Hans-Dieter

    2010-10-14

    Ratings in journal peer review can be affected by sources of bias. The bias variable investigated here was the information on whether authors had suggested a possible reviewer for their manuscript, and whether the editor had taken up that suggestion or had chosen a reviewer that had not been suggested by the authors. Studies have shown that author-suggested reviewers rate manuscripts more favorably than editor-suggested reviewers do. Reviewers' ratings on three evaluation criteria and the reviewers' final publication recommendations were available for 552 manuscripts (in total 1145 reviews) that were submitted to Atmospheric Chemistry and Physics, an interactive open access journal using public peer review (authors' and reviewers' comments are publicly exchanged). Public peer review is supposed to bring a new openness to the reviewing process that will enhance its objectivity. In the statistical analysis the quality of a manuscript was controlled for to prevent favorable reviewers' ratings from being attributable to quality instead of to the bias variable. Our results agree with those from other studies that editor-suggested reviewers rated manuscripts between 30% and 42% less favorably than author-suggested reviewers. Against this backdrop journal editors should consider either doing without the use of author-suggested reviewers or, if they are used, bringing in more than one editor-suggested reviewer for the review process (so that the review by author-suggested reviewers can be put in perspective).

  20. Application of MALDI-TOF MS Systems in the Rapid Identification of Campylobacter spp. of Public Health Importance.

    PubMed

    Hsieh, Ying-Hsin; Wang, Yun F; Moura, Hercules; Miranda, Nancy; Simpson, Steven; Gowrishankar, Ramnath; Barr, John; Kerdahi, Khalil; Sulaiman, Irshad M

    2018-05-01

    Campylobacteriosis is an infectious gastrointestinal disease caused by Campylobacter spp. In most cases, it is either underdiagnosed or underreported due to poor diagnostics and limited databases. Several DNA-based molecular diagnostic techniques, including 16S ribosomal RNA (rRNA) sequence typing, have been widely used in the species identification of Campylobacter. Nevertheless, these assays are time-consuming and require a high quality of bacterial DNA. Matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) MS is an emerging diagnostic technology that can provide the rapid identification of microorganisms by using their intact cells without extraction or purification. In this study, we analyzed 24 American Type Culture Collection reference isolates of 16 Campylobacter spp. and five unknown clinical bacterial isolates for rapid identification utilizing two commercially available MADI-TOF MS platforms, namely the bioMérieux VITEK® MS and Bruker Biotyper systems. In addition, 16S rRNA sequencing was performed to confirm the species-level identification of the unknown clinical isolates. Both MALDI-TOF MS systems identified the isolates of C. jejuni, C. coli, C. lari, and C. fetus. The results of this study suggest that the MALDI-TOF MS technique can be used in the identification of Campylobacter spp. of public health importance.

  1. HPLC-DAD and HPLC-ESI-MS/MS methods for metabolite profiling of propolis extracts.

    PubMed

    Pellati, Federica; Orlandini, Giulia; Pinetti, Diego; Benvenuti, Stefania

    2011-07-15

    In this study, the composition of polyphenols (phenolic acids and flavonoids) in propolis extracts was investigated by HPLC-DAD and HPLC-ESI-MS/MS by comparing the performance of ion trap and triple quadrupole mass analyzers. The analyses were carried out on an Ascentis C(18) column (250mm×4.6mm I.D., 5μm), with a mobile phase composed by 0.1% formic acid in water and acetonitrile. Overall, the UV spectra, the MS and MS/MS data allowed the identification of 40 compounds. In the case of flavonoids, the triple quadrupole mass analyzer provided more collision energy if compared with the ion trap, originating product ions at best sensitivity. The HPLC method was validated in agreement with ICH guidelines: the correlation coefficients were >0.998; the limit of detection was in the range 1.6-4.6μg/ml; the recovery range was 96-105%; the intra- and inter-day %RSD values for retention times and peak areas were found to be <0.3 and 1.9%, respectively. The developed technique was applied to the analysis of hydroalcoholic extracts of propolis available on the Italian market. Although the chromatographic profile of the analyzed samples was similar, the quantitative analysis indicated that there is a great variability in the amount of the active compounds: the content of total phenolic acids ranged from 0.17 to 16.67mg/ml and the level of total flavonoids from 2.48 to 41.10mg/ml. The proposed method can be considered suitable for the phytochemical analysis of propolis extracts used in phytotherapy. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Physiological and Thermal Responses of MS Patients to Head and Vest Cooling: A Case Study

    NASA Technical Reports Server (NTRS)

    Luna, Bernadette; Webbon, Bruce W.; Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Kliss, Mark (Technical Monitor)

    1997-01-01

    Personal cooling systems are used to alleviate symptoms of multiple sclerosis (MS) and to prevent increased core temperature during daily activities. The objective of this study was to determine the operating characteristics and the physiologic changes produced by short term application of the stationary thermal control system used by most clinical institutions. The Life Enhancement Tech (LET) Mark VII portable cooling system and a lightweight Head-vest active cooling garment were used to cool the head and chest regions of 4 male and 3 female MS patients (30 to 66 yrs. old) in this study. The subjects, seated in an upright position at normal room temperature (approx. 24 C), were tested for 60 min. with the liquid cooling garment (LCG) operated at 50 F. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures, heart rate, respiration, and an activity index were recorded continuously on a U.F.I., Inc., Biolog ambulatory monitor. All temperature responses showed extreme variation among subjects. The cold-sensitive subject's rectal temperature increased initially in response to cooling; the heat sensitive subject's rectal temperature decreased. After 40 min. of cooling and during recovery, all subjects'rectal temperatures decreased. Oral temperatures began to decrease after 30 min. of cooling. After 60 min. of cooling, temperature drops ranged from approx. 0.3 - 0.8 C. Oral temperatures continued to decrease during recovery (approx. 0.2 C). The car temperature of the heat sensitive subject was increased after cooling, other subjects exhibited an ear temperature decrease (0.0 - 0.5 C). These data indicate that head and vest cooling may be used to reduce the oral temperatures of MS patients by the approximate amount needed for symptomatic relief as shown by other researchers. The combination of a small subject population and a large subject variance does not permit us to draw statistical

  3. MS/MS library facilitated MRM quantification of native peptides prepared by denaturing ultrafiltration

    PubMed Central

    2012-01-01

    Naturally occurring native peptides provide important information about physiological states of an organism and its changes in disease conditions but protocols and methods for assessing their abundance are not well-developed. In this paper, we describe a simple procedure for the quantification of non-tryptic peptides in body fluids. The workflow includes an enrichment step followed by two-dimensional fractionation of native peptides and MS/MS data management facilitating the design and validation of LC- MRM MS assays. The added value of the workflow is demonstrated in the development of a triplex LC-MRM MS assay used for quantification of peptides potentially associated with the progression of liver disease to hepatocellular carcinoma. PMID:22304756

  4. Methylation-Sensitive High Resolution Melting (MS-HRM).

    PubMed

    Hussmann, Dianna; Hansen, Lise Lotte

    2018-01-01

    Methylation-Sensitive High Resolution Melting (MS-HRM) is an in-tube, PCR-based method to detect methylation levels at specific loci of interest. A unique primer design facilitates a high sensitivity of the assays enabling detection of down to 0.1-1% methylated alleles in an unmethylated background.Primers for MS-HRM assays are designed to be complementary to the methylated allele, and a specific annealing temperature enables these primers to anneal both to the methylated and the unmethylated alleles thereby increasing the sensitivity of the assays. Bisulfite treatment of the DNA prior to performing MS-HRM ensures a different base composition between methylated and unmethylated DNA, which is used to separate the resulting amplicons by high resolution melting.The high sensitivity of MS-HRM has proven useful for detecting cancer biomarkers in a noninvasive manner in urine from bladder cancer patients, in stool from colorectal cancer patients, and in buccal mucosa from breast cancer patients. MS-HRM is a fast method to diagnose imprinted diseases and to clinically validate results from whole-epigenome studies. The ability to detect few copies of methylated DNA makes MS-HRM a key player in the quest for establishing links between environmental exposure, epigenetic changes, and disease.

  5. A survey study comparing young adults with MS and healthy controls on self-esteem, self-efficacy, mood and quality of life.

    PubMed

    Messmer Uccelli, Michele; Traversa, Silvia; Ponzio, Michela

    2016-09-15

    Studies have shown that people with multiple sclerosis (MS) report low levels of self-efficacy and self-esteem, high levels of anxiety and depression and reduced quality of life. The study aims to assess self-esteem, self-efficacy, mood and quality of life in young adults with MS and to compare them to a healthy control group. The age range for inclusion in the study was between 18 and 35years of age for both groups. Subjects with MS were recruited through the Italian MS Society. Healthy controls were recruited through social media and from a university undergraduate program. Subjects completed an anonymous online questionnaire combining various scales. Group differences on demographic data were assessed using parametric and non-parametric tests. Analyses of covariance (ANCOVA) were performed to evaluate differences between the two groups on scales of self-perception, mood and quality of life, adjusting for potentially confounding factors. Eighty-nine subjects with MS and 109 HC were included in the analysis. ANCOVA failed to demonstrate statistically significant differences between groups on self-esteem (F=0.11, p=0.743), self-efficacy (F=2.22, p=0.138), mood (anxiety F=0.03, p=0.855; depression F=0.06, p=0.812) and quality of life (F=0.08, p=0.772). This study demonstrated that young adults with MS and healthy controls have similar levels of self-esteem and self-efficacy and that they do not differ significantly on measures of mood and quality of life, as previously reported. Copyright © 2016. Published by Elsevier B.V.

  6. Metabolites profiling of Pulsatilla saponin D in rat by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS).

    PubMed

    Ouyang, Hui; Zhou, Maofu; Guo, Yicheng; He, Mingzhen; Huang, Hesong; Ye, Xide; Feng, Yulin; Zhou, Xin; Yang, Shilin

    2014-07-01

    Pulsatilla saponin D, an antitumor substance isolated from traditional Chinese herbal medicine Pulsatilla chinensis (Bge.) Regel, is a promising candidate for new drug development. The purpose of the present study is to establish a simple and practical strategy for the metabolite profiling of Pulsatilla saponin D in vivo. A total of 18 metabolites were identified in rat plasma, urine and feces samples based on MS and MS/MS data by using ESI-Q-TOF-MS/MS, and eight of them (M11-M18) were reported for the first time. The results indicated that deglycosylation, dehydrogenation, hydroxylation and sulfation were the major metabolic transformations of Pulsatilla saponin D in vivo. This study has improved our understanding of the metabolic fate of Pulsatilla saponin D in vivo, and the information gained from the current study is relevant to the pharmacological activity of Pulsatilla saponin D. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Concerns about Quadrupole ICP-MS Lead Isotopic Data and Interpretations in the Environment and Health Fields.

    PubMed

    Gulson, Brian; Kamenov, George D; Manton, William; Rabinowitz, Michael

    2018-04-11

    There has been a massive increase in recent years of the use of lead (Pb) isotopes in attempts to better understand sources and pathways of Pb in the environment and in man or experimental animals. Unfortunately, there have been many cases where the quality of the isotopic data, especially that obtained by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS), are questionable, resulting in questionable identification of potential sources, which, in turn, impacts study interpretation and conclusions. We present several cases where the isotopic data have compromised interpretation because of the use of only the major isotopes 208 Pb/ 206 Pb and 207 Pb/ 206 Pb, or their graphing in other combinations. We also present some examples comparing high precision data from thermal ionization (TIMS) or multi-collector plasma mass spectrometry (MC-ICP-MS) to illustrate the deficiency in the Q-ICP-MS data. In addition, we present cases where Pb isotopic ratios measured on Q-ICP-MS are virtually impossible for terrestrial samples. We also evaluate the Pb isotopic data for rat studies, which had concluded that Pb isotopic fractionation occurs between different organs and suggest that this notion of biological fractionation of Pb as an explanation for isotopic differences is not valid. Overall, the brief review of these case studies shows that Q-ICP-MS as commonly practiced is not a suitable technique for precise and accurate Pb isotopic analysis in the environment and health fields.

  8. Concerns about Quadrupole ICP-MS Lead Isotopic Data and Interpretations in the Environment and Health Fields

    PubMed Central

    Gulson, Brian; Manton, William; Rabinowitz, Michael

    2018-01-01

    There has been a massive increase in recent years of the use of lead (Pb) isotopes in attempts to better understand sources and pathways of Pb in the environment and in man or experimental animals. Unfortunately, there have been many cases where the quality of the isotopic data, especially that obtained by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS), are questionable, resulting in questionable identification of potential sources, which, in turn, impacts study interpretation and conclusions. We present several cases where the isotopic data have compromised interpretation because of the use of only the major isotopes 208Pb/206Pb and 207Pb/206Pb, or their graphing in other combinations. We also present some examples comparing high precision data from thermal ionization (TIMS) or multi-collector plasma mass spectrometry (MC-ICP-MS) to illustrate the deficiency in the Q-ICP-MS data. In addition, we present cases where Pb isotopic ratios measured on Q-ICP-MS are virtually impossible for terrestrial samples. We also evaluate the Pb isotopic data for rat studies, which had concluded that Pb isotopic fractionation occurs between different organs and suggest that this notion of biological fractionation of Pb as an explanation for isotopic differences is not valid. Overall, the brief review of these case studies shows that Q-ICP-MS as commonly practiced is not a suitable technique for precise and accurate Pb isotopic analysis in the environment and health fields. PMID:29641487

  9. Fast targeted analysis of 132 acidic and neutral drugs and poisons in whole blood using LC-MS/MS.

    PubMed

    Di Rago, Matthew; Saar, Eva; Rodda, Luke N; Turfus, Sophie; Kotsos, Alex; Gerostamoulos, Dimitri; Drummer, Olaf H

    2014-10-01

    The aim of this study was to develop an LC-MS/MS based screening technique that covers a broad range of acidic and neutral drugs and poisons by combining a small sample volume and efficient extraction technique with simple automated data processing. After protein precipitation of 100μL of whole blood, 132 common acidic and neutral drugs and poisons including non-steroidal anti-inflammatory drugs, barbiturates, anticonvulsants, antidiabetics, muscle relaxants, diuretics and superwarfarin rodenticides (47 quantitated, 85 reported as detected) were separated using a Shimadzu Prominence HPLC system with a C18 separation column (Kinetex XB-C18, 4.6mm×150mm, 5μm), using gradient elution with a mobile phase of 25mM ammonium acetate buffer (pH 7.5)/acetonitrile. The drugs were detected using an ABSciex(®) API 2000 LC-MS/MS system (ESI+ and -, MRM mode, two transitions per analyte). The method was fully validated in accordance with international guidelines. Quantification data obtained using one-point calibration compared favorably to that using multiple calibrants. The presented LC-MS/MS assay has proven to be applicable for determination of the analytes in blood. The fast and reliable extraction method combined with automated processing gives the opportunity for high throughput and fast turnaround times for forensic and clinical toxicology. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Simultaneous determination of five components in rat plasma by UPLC-MS/MS and its application to a comparative pharmacokinetic study in Baihe Zhimu Tang and Zhimu extract.

    PubMed

    Li, Guolong; Tang, Zhishu; Yang, Jie; Duan, Jinao; Qian, Dawei; Guo, Jianming; Zhu, Zhenhua; Liu, Hongbo

    2015-04-15

    Baihe Zhimu Tang (BZT) is a famous traditional Chinese medicine recipe to treat dry coughing due to yin deficiency and for moisturizing the lungs. Zhimu is an essential ingredient in BZT used to treat inflammation, fever and diabetes. The most important active components in Zhimu are flavonoids such as neomangiferin, mangiferin, and steroid saponins (e.g., timosaponin BII, anemarsaponin BIII, timosaponin AIII). The aim of this study was to compare the pharmacokinetics of mangiferin, neomangiferin, timosaponin BII, anemarsaponin BIII and timosaponin AIII in rat plasma after oral administration of BZT and Zhimu extract (ZME). A sensitive, reliable and robust LC-MS/MS method to simultaneously determine steroid saponins and flavonoids in rat plasma was successfully validated. Significant differences (p < 0.05) were found in the pharmacokinetic parameters of timosaponin BII, anemarsaponin BIII and timosaponin AIII between BZT and ZME. It was surmised that formula compatibility could significantly influence the pharmacokinetics of BZT and our study is the first to study the administration of BZT based on pharmacokinetic studies.

  11. Thrombin generation correlates with disease duration in multiple sclerosis (MS): Novel insights into the MS-associated prothrombotic state.

    PubMed

    Parsons, Martin Em; O'Connell, Karen; Allen, Seamus; Egan, Karl; Szklanna, Paulina B; McGuigan, Christopher; Ní Áinle, Fionnuala; Maguire, Patricia B

    2017-01-01

    Thrombin is well recognised for its role in the coagulation cascade but it also plays a role in inflammation, with enhanced thrombin generation observed in several inflammatory disorders. Although patients with multiple sclerosis (MS) have a higher incidence of thrombotic disease, thrombin generation has not been studied to date. The aim of this study was to characterise calibrated automated thrombography parameters in patients with relapsing-remitting MS (RRMS) and primary progressive MS (PPMS) in comparison to healthy controls (HCs). Calibrated automated thrombography was performed on platelet poor plasma from 15 patients with RRMS, 15 with PPMS and 19 HCs. We found that patients with RRMS generate thrombin at a significantly faster rate than the less inflammatory subtype, PPMS or HCs. In addition, the speed of thrombin generation was significantly correlated with time from clinical diagnosis in both subtypes. However, in RRMS the rate of thrombin generation was increased with increased time from clinical diagnosis, while in PPMS the rate of thrombin generation decreased with increased time from clinical diagnosis. These data likely reflect the differential active proinflammatory states in each MS subtype and provide novel mechanistic insights into the clinically relevant prothrombotic state observed in these patients.

  12. Changes to anti-JCV antibody levels in a Swedish national MS cohort

    PubMed Central

    Warnke, Clemens; Ramanujam, Ryan; Plavina, Tatiana; Bergström, Tomas; Goelz, Susan; Subramanyam, Meena; Kockum, Ingrid; Rahbar, Afsar; Kieseier, Bernd C; Holmén, Carolina; Olsson, Tomas; Hillert, Jan; Fogdell-Hahn, Anna

    2013-01-01

    Background The anti-JC virus (JCV) antibody status has been introduced to stratify patients with multiple sclerosis (MS) for higher or lower risk of progressive multifocal leukoencephalopathy (PML). Objective To assess the potential utility of anti-JCV antibody levels for earlier diagnosis or prediction of PML. Methods An analytically validated antibody assay was used to determine serological status, normalised optical density values, and dilution titres for anti-JCV antibodies. The method was applied to stored sera of 1157 patients with MS including five cases of PML, all enrolled in the Swedish pharmacovigilance study for natalizumab (NAT). Anticytomegalovirus (CMV) and antivaricella-zoster (VZV) antibody levels served as controls. Results Prior to treatment with NAT, anti-JCV antibody levels were stable in the anti-JCV positive patients. During therapy, a slight decrease in anti-JCV and anti-VZV antibody levels, but not anti-CMV antibody levels, was observed. All five patients who developed PML showed a mild to moderate increase in anti-JCV antibody levels at time of PML diagnosis; pre-PML samples suggested that this increase might start already prior to diagnosis of PML. Conclusions Treatment initiation with NAT may lead to a slight decrease in anti-JCV and anti-VZV antibody levels, suggestive of a mild suppressive effect of NAT on antibody levels. Our findings in five cases of PML demonstrate that the onset of PML can be accompanied by increasing anti-JCV antibodies in serum. Monitoring of anti-JCV antibody levels could potentially be used as a tool for prediction or earlier diagnosis of PML during NAT treatment for MS. Further studies are warranted. PMID:23463870

  13. Burnout and Depression in MS1 and MS3 Years: A Comparison of Cohorts at One Medical School.

    PubMed

    Elkins, Cinthia; Plante, Kyle P; Germain, Lauren J; Morley, Christopher P

    2017-06-01

    Losses of idealism, empathy, and professionalism over the course of medical education have been described previously in the literature. A 2012 national survey of medical students estimated 37%-44% with burnout, 58% screen positive for depression, and 9.4% with suicidal ideation in the past 12 months. Given changes in related traits, we sought to explore whether burnout and symptoms of depression change over time. The objectives of this study were to assess the differences in medical student burnout and symptoms of depression between first year (MS1) and third-year (MS3) medical students at one medical college. Students were administered the modified Maslach Burnout Inventory (MBI) and the Patient Health Questionnaire-2 (PHQ-2) depression screening instrument as an optional part of a mandatory annual survey administered by the medical college near the end of the academic year (March-May, 2015). Anonymous responses from MS1s and MS3s were analyzed to estimate trends in burnout and possible depression over time and to examine the relationship between the two measures. Possible depression (Total PHQ2 equal or greater than 3) was present in 28.5% of all respondents. MS3s had significantly higher levels of Emotional Exhaustion (EE) and Depersonalization (DP), and lower levels of Personal Accomplishment (PA), than MS1s. When PHQ2, gender, and campus/program effects were controlled via regression, MS3s tended to record EE and DP scores over 2 points higher than MS1s and PA scores over 2 points lower. Regrets about entering medicine were also higher in MS3s in the controlled models. PHQ2 scores were also positively associated with all subscales except for PA. Students appear to be at slightly greater risk for burnout as they temporally progress through medical school. These findings are consistent with similar measurements of decreasing empathy and idealism when comparing cohorts of early versus late medical students.

  14. Identification of prohibitin 1 as a potential prognostic biomarker in human pancreatic carcinoma using modified aqueous two-phase partition system combined with 2D-MALDI-TOF-TOF-MS/MS.

    PubMed

    Zhong, Ning; Cui, Yazhou; Zhou, Xiaoyan; Li, Tianliang; Han, Jinxiang

    2015-02-01

    Membrane proteins are an important source of potential targets for anticancer drugs or biomarkers for early diagnosis. In this study, we used a modified aqueous two-phase partition system combined with two-dimensional (2D) matrix-assisted laser desorption ionization (MALDI) time of flight (TOF) mass spectrometry (MS, 2D-MALDI-TOF-TOF-MS/MS) analysis to isolate and identify membrane proteins in PANC-1 pancreatic cancer cells. Using this method, we identified 55 proteins, of which 31 (56.4 %) were membrane proteins, which, according to gene ontology annotation, are associated with various cellular processes including cell signal transduction, differentiation, and apoptosis. Immunohistochemical analysis showed that the expression level of one of the identified mitochondria membrane proteins, prohibitin 1 (PHB1), is correlated with pancreatic carcinoma differentiation; PHB1 is expressed at a higher level in normal pancreatic tissue than in well-differentiated carcinoma tissue. Further studies showed that PHB1 plays a proapoptotic role in human pancreatic cancer cells, which suggests that PHB1 has antitumorigenic properties. In conclusion, we have provided a modified method for isolating and identifying membrane proteins and demonstrated that PHB1 may be a promising biomarker for early diagnosis and therapy of pancreatic (and potentially other) cancers.

  15. Characterization of a mixture of lobster digestive cysteine proteinases by ionspray mass spectrometry and tryptic mapping with LC--MS and LC--MS--MS

    NASA Astrophysics Data System (ADS)

    Thibault, P.; Pleasance, S.; Laycock, M. V.; Mackay, R. M.; Boyd, R. K.

    1991-12-01

    An inseparable mixture of two cysteine proteinases, isolated from the digestive tract of the American lobster, was investigated by ionspray mass spectrometry (ISP-MS), using a combination of infusion of intact proteins with on-line liquid chromatography--mass spectrometry (LC--MS) and LC--MS--MS analyses of tryptic digests. These data were interpreted by comparisons with predictions from results of molecular cloning of cysteine-proteinase-encoding messenger RNA sequences previously isolated from the lobster hepatopancreas. Investigations of the numbers of free thiol groups and of disulfide bonds were made by measuring the molecular weights of the alkylated proteins with and without prior reduction of disulfide bonds, and comparison with the corresponding data for the native proteins. Identification of tyrptic fragment peptides containing cysteine residues was facilitated by comparing LC--MS analyses of tryptic digests of denatured and of denatured and alkylated proteins, since such tryptic peptides are subject to shifts in both mass and retention time upon reduction and alkylation. Confirmation of amino acid sequences was obtained from fragment ion spectra of each tryptic peptide (alkylated or not) as it eluted from the column. Acquisition of such on-line LC--MS data was possible through use of the entire effluent from a standard 1 mm high performance liquid chromatography (HPLC) column by an IonsSpray® LC--MS interface (pneumatically assisted electrospray).

  16. Turnover and urinary excretion of free and acetylated MS-222 rainbow trout, Salmo gairdneri

    USGS Publications Warehouse

    Hunn, J.B.; Schoettger, R.A.; Willford, W.A.

    1968-01-01

    Rainbow trout (Salmo gairdneri) anesthetized in 100 mg/liter of M.S. 222 at 12 C excreted the drug in free and acetylated forms via the urine during a 24-hr recovery period in freshwater. Of the M.S. 222 excreted, 77-96% was acetylated. Blood levels of free drug in anesthetized trout approximated 75% of the anesthetic concentration, but the amount of acetylated M.S. 222 was relatively insignificant. The blood and urine were cleared of the two fractions of M.S. 222 in 8 and 24 hr respectively. Low levels of aromatic amines of natural origin occurred in blood and urine and were subtracted from measurements of M.S. 222. Intraperitoneal injections of 10-100 mg/kg of M.S. 222 did not induce anesthesia; however, the 24-hr pattern of drug excretion was similar to that observed after anesthesia by immersion. Only 15-21 % of the injected dose was found in the urine, suggesting a second route of drug elimination.

  17. Simultaneous quantification of multiple components in rat plasma by UPLC-MS/MS and pharmacokinetic study after oral administration of Huangqi decoction.

    PubMed

    Zeng, Jia-Kai; Li, Yuan-Yuan; Wang, Tian-Ming; Zhong, Jie; Wu, Jia-Sheng; Liu, Ping; Zhang, Hua; Ma, Yue-Ming

    2018-05-01

    A rapid, sensitive and accurate UPLC-MS/MS method was developed for the simultaneous quantification of components of Huangqi decoction (HQD), such as calycosin-7-O-β-d-glucoside, calycosin-glucuronide, liquiritin, formononetin-glucuronide, isoliquiritin, liquiritigenin, ononin, calycosin, isoliquiritigenin, formononetin, glycyrrhizic acid, astragaloside IV, cycloastragenol, and glycyrrhetinic acid, in rat plasma. After plasma samples were extracted by protein precipitation, chromatographic separation was performed with a C 18 column, using a gradient of methanol and 0.05% acetic acid containing 4mm ammonium acetate as the mobile phase. Multiple reaction monitoring scanning was performed to quantify the analytes, and the electrospray ion source polarity was switched between positive and negative modes in a single run of 10 min. Method validation showed that specificity, linearity, accuracy, precision, extraction recovery, matrix effect and stability for 14 components met the requirements for their quantitation in biological samples. The established method was successfully applied to the pharmacokinetic study of multiple components in rats after intragastric administration of HQD. The results clarified the pharmacokinetic characteristics of multiple components found in HQD. This research provides useful information for understanding the relation between the chemical components of HQD and their therapeutic effects. Copyright © 2017 John Wiley & Sons, Ltd.

  18. EPA CRL MS014: Analysis of Aldicarb, Bromadiolone, Carbofuran, Oxamyl and Methomyl in Water by Multiple Reaction Monitoring Liquid Chromatography / Tandem Mass Spectrometry (LC/MS/MS)

    EPA Pesticide Factsheets

    Method MS014 describes procedures for solvent extraction of aldicarb, bromadiolone, carbofuran, oxamyl and methomyl from water samples, followed by analysis using liquid chromatography tandem mass spectrometry (LC-MS-MS).

  19. Eco-friendly LC-MS/MS method for analysis of multi-class micropollutants in tap, fountain, and well water from northern Portugal.

    PubMed

    Barbosa, Marta O; Ribeiro, Ana R; Pereira, Manuel F R; Silva, Adrián M T

    2016-11-01

    Organic micropollutants present in drinking water (DW) may cause adverse effects for public health, and so reliable analytical methods are required to detect these pollutants at trace levels in DW. This work describes the first green analytical methodology for multi-class determination of 21 pollutants in DW: seven pesticides, an industrial compound, 12 pharmaceuticals, and a metabolite (some included in Directive 2013/39/EU or Decision 2015/495/EU). A solid-phase extraction procedure followed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (offline SPE-UHPLC-MS/MS) method was optimized using eco-friendly solvents, achieving detection limits below 0.20 ng L -1 . The validated analytical method was successfully applied to DW samples from different sources (tap, fountain, and well waters) from different locations in the north of Portugal, as well as before and after bench-scale UV and ozonation experiments in spiked tap water samples. Thirteen compounds were detected, many of them not regulated yet, in the following order of frequency: diclofenac > norfluoxetine > atrazine > simazine > warfarin > metoprolol > alachlor > chlorfenvinphos > trimethoprim > clarithromycin ≈ carbamazepine ≈ PFOS > citalopram. Hazard quotients were also estimated for the quantified substances and suggested no adverse effects to humans. Graphical Abstract Occurrence and removal of multi-class micropollutants in drinking water, analyzed by an eco-friendly LC-MS/MS method.

  20. Validated UPLC-MS/MS method for quantification of seven compounds in rat plasma and tissues: Application to pharmacokinetic and tissue distribution studies in rats after oral administration of extract of Eclipta prostrata L.

    PubMed

    Du, Guangyan; Fu, Lingling; Jia, Jun; Pang, Xu; Yu, Haiyang; Zhang, Youcai; Fan, Guanwei; Gao, Xiumei; Han, Lifeng

    2018-06-01

    A rapid, sensitive and specific ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method was developed to investigate the pharmacokinetics and tissue distribution of Eclipta prostrata extract. Rats were orally administrated the 70% ethanol extract of E. prostrata, and their plasma as well as various organs were collected. The concentrations of seven main compounds, ecliptasaponin IV, ecliptasaponin A, apigenin, 3'-hydroxybiochanin A, luteolin, luteolin-7-O-glucoside and wedelolactone, were quantified by UPLC-MS/MS through multiple reactions monitoring method. The precisions (RSD) of the analytes were all <15.00%. The extraction recoveries ranged from 74.65 to 107.45% with RSD ≤ 15.36%. The matrix effects ranged from 78.00 to 118.06% with RSD ≤ 15.04%. To conclude, the present pharmacokinetic and tissue distribution studies provided useful information for the clinical usage of Eclipta prostrata L. Copyright © 2018 John Wiley & Sons, Ltd.

  1. Chemical fingerprinting and quantitative constituent analysis of Siwu decoction categorized formulae by UPLC-QTOF/MS/MS and HPLC-DAD

    PubMed Central

    2013-01-01

    Background Siwu decoction categorized formulae (SWDCF) are widely used for treating gynecological diseases. This study aims to elucidate the differences of bioactive constituents in SWDCF by ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC - QTOF - MS /MS) and HPLC-DAD. Methods An efficient method based on UPLC - QTOF - MS /MS was developed for identifying the chemical profiles of SWDCF. HPLC-DAD method was used for quantifying seven chemical markers in SWDCF. Results Eighty four components were identified or characterized, including ten organic acids, thirty glycosides (monoterpene or iridoid or phenylpropanoids glycosides), fourteen lactones, eighteen flavonoids, and eleven alkaloids in the complex system. The datasets of tR-m/z pairs, ion intensities and sample codes were processed with supervised orthogonal partial least squared discriminant analysis to compare these decoction samples. After a clear classification was established, OPLS-DA was performed and 16 common components with relative quantity in SWDCF samples were determined. Gallic acid, protocatechuic acid, vanillic acid, caffeic acid, paeoniflorin, ferulic acid, and senkyunolide I were selected as the chemical markers to identify SWDCF by HPLC-DAD. Conclusion The chemical profiles with 84 components in SWDCF, including monoterpene glycosides, acetophenones, galloyl glucoses, even some isomers in the complex system were characterized by UPLC–QTOF–MS/MS. PMID:23453004

  2. Polyphasic Approach Including MALDI-TOF MS/MS Analysis for Identification and Characterisation of Fusarium verticillioides in Brazilian Corn Kernels

    PubMed Central

    Chang, Susane; Porto Carneiro-Leão, Mariele; Ferreira de Oliveira, Benny; Souza-Motta, Cristina; Lima, Nelson; Santos, Cledir; Tinti de Oliveira, Neiva

    2016-01-01

    Fusarium verticillioides is considered one of the most important global sources of fumonisins contamination in food and feed. Corn is one of the main commodities produced in the Northeastern Region of Brazil. The present study investigated potential mycotoxigenic fungal strains belonging to the F. verticillioides species isolated from corn kernels in 3 different Regions of the Brazilian State of Pernambuco. A polyphasic approach including classical taxonomy, molecular biology, MALDI-TOF MS and MALDI-TOF MS/MS for the identification and characterisation of the F. verticillioides strains was used. Sixty F. verticillioides strains were isolated and successfully identified by classical morphology, proteomic profiles of MALDI-TOF MS, and by molecular biology using the species-specific primers VERT-1 and VERT-2. FUM1 gene was further detected for all the 60 F. verticillioides by using the primers VERTF-1 and VERTF-2 and through the amplification profiles of the ISSR regions using the primers (GTG)5 and (GACA)4. Results obtained from molecular analysis shown a low genetic variability among these isolates from the different geographical regions. All of the 60 F. verticillioides isolates assessed by MALDI-TOF MS/MS presented ion peaks with the molecular mass of the fumonisin B1 (721.83 g/mol) and B2 (705.83 g/mol). PMID:26927172

  3. Simultaneous determination of multicomponent of acetylkitasamycin and kitasamycin by LC-MS/MS in swine plasma and its application in a pharmacokinetic study.

    PubMed

    Pan, Yuanhu; Zhang, Heying; Xi, Chenglong; Huang, Lingli; Xie, Shuyu; Chen, Dongmei; Tao, Yanfei; Liu, Zhenli; Yuan, Zonghui

    2018-05-02

    A simple and reliable LC-MS/MS method was established for simultaneous determination of twelve components from acetylkitasamycin and kitasamycin in swine plasma. The analytes were separated by a Shim-pack VP-ODS column with a 25 min gradient elution using 5 mmol/L ammonium acetate and acetonitrile as the mobile phase at a flow rate of 0.2 mL/min. Identification and quantification were accomplished by electrospray ionization (ESI) in positive mode using multiple reaction monitoring (MRM). The LOQ S of acetylkitasamycin A 1 A 3 , A 13 and kitasamycin A 3 , A 13 were 3 μg/L, and that of the other 8 components were 5 μg/L. The mean recoveries of kitasamycin and acetylkitasamycin ranged from 85.3 to 103.5 %. The developed method was successfully applied to a pharmacokinetic study in swine after intravenous (IV) and oral (PO) administration of acetylkitasamycin. The result showed that the plasma concentrations of acetylkitsamycin components were much higher than that of kitasamycin in swine after IV and PO, in which acetylkitsamycin A 4 A 5 was the highest component at each time point. This article is protected by copyright. All rights reserved.

  4. Absenteeism and health-benefit costs among employees with MS.

    PubMed

    Brook, Richard A; Rajagopalan, Krithika; Kleinman, Nathan L; Melkonian, Arthur K

    2009-06-01

    The purpose of this analysis was to assess the differences in lost time and health-benefit costs (HBCs) among employees treated with disease modifying treatments (DMTs) for multiple sclerosis (MS). Employees with an MS diagnostic code (ICD-9 340.xx) and a DMT prescription claim (1/1/2001-6/30/2007) were identified from the HCMS Research Reference Database and assigned to DMT cohorts. The first prescription for the DMT was used as each person's index date. One-year outcomes included HBCs and absenteeism (lost time, comprising sick leave [SL], short- and long-term disability [STD/LTD], and workers' compensation). Demographics were compared using t-tests for continuous variables and chi-square tests for discrete variables. Two-part multivariate regression modeling (logistic regression combined with generalized linear regression) was used to determine annual HBCs and absenteeism for each cohort controlling for age, gender, job-related variables, and Charlson Comorbidity Score. All cost variables were inflated to US$2007. Annual ranges among the DMTs were: HBCs $17,953-26,970 and absenteeism 7.33-20.67 days. Compared with glatiramer acetate ('C'), IFN-beta1a IM ('A') users had lower SL ($445, p = 0.0469) and STD ($969, p = 0.0164) costs; and IFN-beta1b ('B') users had lower medical costs ($2143, p = 0.0091). In addition, those treated with 'A' had 4.2 fewer SL days (p = 0.0101) compared with those treated with 'C'. Patients treated with 'A' reported significantly lower SL costs, SL days, and STD costs than patients treated with 'C', suggestive of greater real world benefits with 'A'. Despite small sample sizes and the retrospective nature, the study provides interesting insights into the use of DMTs in MS. The study also revealed important areas of future research, specifically the need for development of methods to determine which MS patient groups respond best to which DMT treatments.

  5. CE-MS for metabolomics: developments and applications in the period 2012-2014.

    PubMed

    Ramautar, Rawi; Somsen, Govert W; de Jong, Gerhardus J

    2015-01-01

    In the field of metabolomics, CE-MS is now regarded as a useful complementary analytical technique for the profiling of (highly) polar ionogenic metabolites in biological samples. Over the past few years, significant advancements have been made in CE-MS approaches for metabolic profiling studies. This paper, which is a follow-up of three previous review papers covering the years 2000-2012 [Electrophoresis 2009, 30, 276-291; Electrophoresis 2011, 32, 52-65; Electrophoresis 2013, 34, 86-98], provides an update of these developments covering the scientific literature from July 2012 to June 2014. Attention will be paid to novel interfacing techniques for coupling CE to MS and their implications for metabolomics studies. The potential of CEC-MS and MEKC-MS are also considered, and CE-MS systems for high-throughput metabolic profiling are discussed. The applicability of CE-MS for metabolomics studies is demonstrated by representative examples in the fields of biomedical, clinical, microbial, plant, environmental, and food metabolomics. An overview of recent CE-MS-based metabolomics studies is given in a table, which provides information on sample type and pretreatment, capillary coatings, and MS detection mode. Finally, general conclusions and perspectives are given. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Isotope ratios of trace elements in samples from human nutrition studies determined by TIMS and ICP-MS: precision and accuracy compared.

    PubMed

    Turnlund, Judith R; Keyes, William R

    2002-09-01

    Stable isotopes are used with increasing frequency to trace the metabolic fate of minerals in human nutrition studies. The precision of the analytical methods used must be sufficient to permit reliable measurement of low enrichments and the accuracy should permit comparisons between studies. Two methods most frequently used today are thermal ionization mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICP-MS). This study was conducted to compare the two methods. Multiple natural samples of copper, zinc, molybdenum, and magnesium were analyzed by both methods to compare their internal and external precision. Samples with a range of isotopic enrichments that were collected from human studies or prepared from standards were analyzed to compare their accuracy. TIMS was more precise and accurate than ICP-MS. However, the cost, ease, and speed of analysis were better for ICP-MS. Therefore, for most purposes, ICP-MS is the method of choice, but when the highest degrees of precision and accuracy are required and when enrichments are very low, TIMS is the method of choice.

  7. Measurement of hydrogen sulfide from oil and natural gas production in the Uintah Basin, Utah using PTR-MS

    NASA Astrophysics Data System (ADS)

    Li, R.; Warneke, C.; Graus, M.; Field, R. A.; Veres, P. R.; Geiger, F.; Soltis, J.; Li, S.; Murphy, S. M.; De Gouw, J. A.

    2013-12-01

    Natural gas production is associated with emissions of a variety of toxic trace gases. While volatile organic compounds (VOCs) have received considerable attention, H2S is also of concern due to the known health impacts of exposure to this hazardous air pollutant. Here, we present quantitative, fast time-response measurements of hydrogen sulfide (H2S) using Proton-Transfer-Reaction Mass-Spectrometry (PTR-MS) instruments. The PTR-MS was operated for measurements of VOCs including H2S at the Horsepool ground site in the Uintah Basin during the Uintah Basin Winter Ozone Study (UBWOS) 2013 campaign. Measurements of H2S from a mobile laboratory in the gas and oil fields were also made by Ultra-Light-Weight PTR-MS (ULW-PTR-MS) during UBWOS 2012. The H2S measurement by PTR-MS is strongly humidity dependent. We compare the humidity dependence determined in the laboratory with in-field calibrations of H2S and determine the H2S mixing ratios for the mobile and ground measurements. The PTR-MS measurements at Horsepool are compared with simultaneous H2S measurements using a Proton-Transfer-Reaction Time-of-Flight (PTR-ToF) and an H2S/CH4 Picarro instrument. The H2S measurements by PTR-MS agree with both instruments within 30% uncertainties. The combination of the two campaigns (UBWOS 2012 & 2013) has shown that on average 1 - 2 ppbv of H2S is present in the Uintah Basin. The correlation between H2S and methane suggests that the source of H2S is associated with the oil and gas extraction in the basin. Significant H2S emissions with mixing ratios of up to 3 ppmv from storage tanks and wells were observed during the mobile lab measurements. This study suggests that H2S emissions associated with oil and gas production can lead to short-term high levels close to point sources, and elevated background levels away from those sources. Our work has also shown that PTR-MS can make reliable measurements of H2S at levels below 1 ppbv.

  8. Do Author-Suggested Reviewers Rate Submissions More Favorably than Editor-Suggested Reviewers? A Study on Atmospheric Chemistry and Physics

    PubMed Central

    Bornmann, Lutz; Daniel, Hans-Dieter

    2010-01-01

    Background Ratings in journal peer review can be affected by sources of bias. The bias variable investigated here was the information on whether authors had suggested a possible reviewer for their manuscript, and whether the editor had taken up that suggestion or had chosen a reviewer that had not been suggested by the authors. Studies have shown that author-suggested reviewers rate manuscripts more favorably than editor-suggested reviewers do. Methodology/Principal Findings Reviewers' ratings on three evaluation criteria and the reviewers' final publication recommendations were available for 552 manuscripts (in total 1145 reviews) that were submitted to Atmospheric Chemistry and Physics, an interactive open access journal using public peer review (authors' and reviewers' comments are publicly exchanged). Public peer review is supposed to bring a new openness to the reviewing process that will enhance its objectivity. In the statistical analysis the quality of a manuscript was controlled for to prevent favorable reviewers' ratings from being attributable to quality instead of to the bias variable. Conclusions/Significance Our results agree with those from other studies that editor-suggested reviewers rated manuscripts between 30% and 42% less favorably than author-suggested reviewers. Against this backdrop journal editors should consider either doing without the use of author-suggested reviewers or, if they are used, bringing in more than one editor-suggested reviewer for the review process (so that the review by author-suggested reviewers can be put in perspective). PMID:20976226

  9. Identification of hydroxyropivacaine glucuronide in equine urine by ESI+/MS/MS.

    PubMed Central

    Harkins, J D; Karpiesiuk, W; Tobin, T; Dirikolu, L; Lehner, A F

    2000-01-01

    Ropivacaine is a local anesthetic that has a high potential for abuse in racing horses. It can be recovered from urine collected after administration as a hydroxylated metabolite following beta-glucuronidase treatment of the urine. Based on these findings, it has been inferred that ropivacaine is present in equine urine as a glucuronide metabolite; however, these metabolites have never been directly identified. Using ESI+/MS/MS, the presence of a [M+H]+ molecular ion of m/z 467 was demonstrated in urine corresponding to the calculated mass of a hydroxyropivacaine glucuronide +1. The abundance of this ion diminished after glucuronidase treatment with concomitant appearance of a m/z 291 peak, which is consistent with its hydrolysis to hydroxyropivacaine. In further work, the m/z 467 material was fragmented in the MS/MS system, yielding fragments interpretable as hydroxyropivacaine glucuronide. These data are consistent with the presence of a hydroxyropivacaine glucuronide in equine urine and constitute the first direct demonstration of a specific glucuronide metabolite in equine urine. PMID:10935884

  10. Development of a patient reported outcome scale for fatigue in multiple sclerosis: The Neurological Fatigue Index (NFI-MS)

    PubMed Central

    2010-01-01

    Background Fatigue is a common and debilitating symptom in multiple sclerosis (MS). Best-practice guidelines suggest that health services should repeatedly assess fatigue in persons with MS. Several fatigue scales are available but concern has been expressed about their validity. The objective of this study was to examine the reliability and validity of a new scale for MS fatigue, the Neurological Fatigue Index (NFI-MS). Methods Qualitative analysis of 40 MS patient interviews had previously contributed to a coherent definition of fatigue, and a potential 52 item set representing the salient themes. A draft questionnaire was mailed out to 1223 people with MS, and the resulting data subjected to both factor and Rasch analysis. Results Data from 635 (51.9% response) respondents were split randomly into an 'evaluation' and 'validation' sample. Exploratory factor analysis identified four potential subscales: 'physical', 'cognitive', 'relief by diurnal sleep or rest' and 'abnormal nocturnal sleep and sleepiness'. Rasch analysis led to further item reduction and the generation of a Summary scale comprising items from the Physical and Cognitive subscales. The scales were shown to fit Rasch model expectations, across both the evaluation and validation samples. Conclusion A simple 10-item Summary scale, together with scales measuring the physical and cognitive components of fatigue, were validated for MS fatigue. PMID:20152031

  11. UPLC-MS/MS Method for Simultaneous Determination of Three Major Metabolites of Mequindox in Holothurian

    PubMed Central

    Liu, Huihui; Han, Dianfeng; Huang, Hui; Xu, Yingjiang; Gong, Xianghong

    2018-01-01

    This study developed an ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the detection of three major metabolites of mequindox, including 3-methyl-quinoxaline-2-carboxylic acid, 1-desoxymequindox, and 1,4-bisdesoxymequindox (MQCA, 1-DMEQ, and BDMEQ), in holothurian. Target analytes were simplified with ultrasound-assisted acidolysis extracted without complicated enzymolysis steps. After that, each sample was centrifuged and purified by an Oasis MAX cartridge. Then, the processed samples were separated and monitored by UPLC-MS/MS. This developed method has been validated according to FDA criteria. At fortified levels of 2, 10, and 20 μg/kg, recoveries ranged from 82.5% to 93.5% with the intraday RSD less than 7.27% and interday RSD less than 11.8%. The limit of detection (LOD) of all the three metabolites ranged from 0.21 to 0.48 μg/kg, while the limit of quantification (LOQ) ranged from 0.79 to 1.59 μg/kg. On application to commercial samples, 14 of 20 samples were detected positive for the three target analytes, with positive rate at 70 percentage. The result indicated that this method was specific, sensitive, and suitable for the quantification and conformation of the three major metabolites of MEQ in holothurian. PMID:29805832

  12. UPLC-MS/MS Method for Simultaneous Determination of Three Major Metabolites of Mequindox in Holothurian.

    PubMed

    Liu, Huihui; Ren, Chuanbo; Han, Dianfeng; Huang, Hui; Zou, Rongjie; Zhang, Huawei; Xu, Yingjiang; Gong, Xianghong; Zhang, Xiuzhen; Li, Yanshen

    2018-01-01

    This study developed an ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the detection of three major metabolites of mequindox, including 3-methyl-quinoxaline-2-carboxylic acid, 1-desoxymequindox, and 1,4-bisdesoxymequindox (MQCA, 1-DMEQ, and BDMEQ), in holothurian. Target analytes were simplified with ultrasound-assisted acidolysis extracted without complicated enzymolysis steps. After that, each sample was centrifuged and purified by an Oasis MAX cartridge. Then, the processed samples were separated and monitored by UPLC-MS/MS. This developed method has been validated according to FDA criteria. At fortified levels of 2, 10, and 20  μ g/kg, recoveries ranged from 82.5% to 93.5% with the intraday RSD less than 7.27% and interday RSD less than 11.8%. The limit of detection (LOD) of all the three metabolites ranged from 0.21 to 0.48  μ g/kg, while the limit of quantification (LOQ) ranged from 0.79 to 1.59  μ g/kg. On application to commercial samples, 14 of 20 samples were detected positive for the three target analytes, with positive rate at 70 percentage. The result indicated that this method was specific, sensitive, and suitable for the quantification and conformation of the three major metabolites of MEQ in holothurian.

  13. Quantification of mevalonate-5-phosphate using UPLC-MS/MS for determination of mevalonate kinase activity.

    PubMed

    Reitzle, Lukas; Maier, Barbara; Stojanov, Silvia; Teupser, Daniel; Muntau, Ania C; Vogeser, Michael; Gersting, Søren W

    2015-08-01

    Mevalonate kinase deficiency, a rare autosomal recessive autoinflammatory disease, is caused by mutations in the MVK gene encoding mevalonate kinase (MK). MK catalyzes the phosphorylation of mevalonic acid to mevalonate-5-phosphate (MVAP) in the pathway of isoprenoid and sterol synthesis. The disease phenotype correlates with residual activity ranging from <0.5% for mevalonic aciduria to 1-7% for the milder hyperimmunoglobulinemia D and periodic fever syndrome (HIDS). Hence, assessment of loss-of-function requires high accuracy measurements. We describe a method using isotope dilution UPLC-MS/MS for precise and sensitive determination of MK activity. Wild-type MK and the variant V261A, which is associated with HIDS, were recombinantly expressed in Escherichia coli. Enzyme activity was determined by formation of MVAP over time quantified by isotope dilution UPLC-MS/MS. The method was validated according to the FDA Guidance for Bioanalytical Method Validation. Sensitivity for detection of MAVP by UPLC-MS/MS was improved by derivatization with butanol-HCl (LLOQ, 5.0 fmol) and the method was linear from 0.5 to 250 μmol/L (R(2) > 0.99) with a precision of ≥ 89% and an accuracy of ± 2.7%. The imprecision of the activity assay, including the enzymatic reaction and the UPLC-MS/MS quantification, was 8.3%. The variant V261A showed a significantly decreased activity of 53.1%. Accurate determination of MK activity was enabled by sensitive and reproducible detection of MVAP using UPLC-MS/MS. The novel method may improve molecular characterization of MVK mutations, provide robust genotype-phenotype correlations, and accelerate compound screening for drug candidates restoring variant MK activity. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  14. Protein profile in HBx transfected cells: a comparative iTRAQ-coupled 2D LC-MS/MS analysis.

    PubMed

    Feng, Huixing; Li, Xi; Niu, Dandan; Chen, Wei Ning

    2010-06-16

    The x protein of HBV (HBx) has been involved in the development of hepatocellular carcinoma (HCC), with a possible link to individual genotypes. Nevertheless, the underlying mechanism remains obscure. In this study, we aim to identify the HBx-induced protein profile in HepG2 cells by LC-MS/MS proteomics analysis. Our results indicated that proteins were differentially expressed in HepG2 cells transfected by HBx of various genotypes. Proteins associated with cytoskeleton were found to be either up-regulated (MACF1, HMGB1, Annexin A2) or down-regulated (Lamin A/C). These may in turn result in the decrease of focal adhesion and increase of cell migration in response to HBx. Levels of other cellular proteins with reported impact on the function of extracellular matrix (ECM) proteins and cell migration, including Ca(2+)-binding proteins (S100A11, S100A6, and S100A4) and proteasome protein (PSMA3), were affected by HBx. The differential protein profile identified in this study was also supported by our functional assay which indicated that cell migration was enhanced by HBx. Our preliminary study provided a new platform to establish a comprehensive cellular protein profile by LC-MS/MS proteomics analysis. Further downstream functional assays, including our reported cell migration assay, should provide new insights in the association between HCC and HBx. Copyright 2009 Elsevier B.V. All rights reserved.

  15. MS disease activity in RESTORE: a randomized 24-week natalizumab treatment interruption study.

    PubMed

    Fox, Robert J; Cree, Bruce A C; De Sèze, Jerome; Gold, Ralf; Hartung, Hans-Peter; Jeffery, Douglas; Kappos, Ludwig; Kaufman, Michael; Montalbán, Xavier; Weinstock-Guttman, Bianca; Anderson, Britt; Natarajan, Amy; Ticho, Barry; Duda, Petra

    2014-04-29

    RESTORE was a randomized, partially placebo-controlled exploratory study evaluating multiple sclerosis (MS) disease activity during a 24-week interruption of natalizumab. Eligible patients were relapse-free through the prior year on natalizumab and had no gadolinium-enhancing lesions on screening brain MRI. Patients were randomized 1:1:2 to continue natalizumab, to switch to placebo, or to receive alternative immunomodulatory therapy (other therapies: IM interferon β-1a [IM IFN-β-1a], glatiramer acetate [GA], or methylprednisolone [MP]). During the 24-week randomized treatment period, patients underwent clinical and MRI assessments every 4 weeks. Patients (n = 175) were randomized to natalizumab (n = 45), placebo (n = 42), or other therapies (n = 88: IM IFN-β-1a, n = 17; GA, n = 17; MP, n = 54). Of 167 patients evaluable for efficacy, 49 (29%) had MRI disease activity recurrence: 0/45 (0%) natalizumab, 19/41 (46%) placebo, 1/14 (7%) IM IFN-β-1a, 8/15 (53%) GA, and 21/52 (40%) MP. Relapse occurred in 4% of natalizumab patients and in 15%-29% of patients in the other treatment arms. MRI disease activity recurred starting at 12 weeks (n = 3 at week 12) while relapses were reported as early as 4-8 weeks (n = 2 in weeks 4-8) after the last natalizumab dose. Overall, 50/167 patients (30%), all in placebo or other-therapies groups, restarted natalizumab early because of disease activity. MRI and clinical disease activity recurred in some patients during natalizumab interruption, despite use of other therapies. This study provides Class II evidence that for patients with MS taking natalizumab who are relapse-free for 1 year, stopping natalizumab increases the risk of MS relapse or MRI disease activity as compared with continuing natalizumab.

  16. A validated LC-MS/MS determination method for the illegal food additive rhodamine B: Applications of a pharmacokinetic study in rats.

    PubMed

    Cheng, Yung-Yi; Tsai, Tung-Hu

    2016-06-05

    Rhodamine B is an illegal and potentially carcinogenic food dye. The aim of this study was to develop a convenient, rapid, and sensitive UHPLC-MS/MS method for pharmacokinetic studies in rats. Rat plasma samples were deproteinized with acetonitrile and separated by UHPLC on a reverse-phase C18e column (100mm×2.1mm, 2μm) using a mobile phase consisting of methanol-5mM ammonium acetate (90:10, v/v). Detection was performed using a triple quadrupole tandem mass spectrometer in the selected reaction monitoring mode at [M](+) ion m/z 443.39→399.28 for rhodamine B and [M+H](+) ion m/z 253.17→238.02 for 5-methoxyflavone as the internal standard. This method was specific and produced linear results over a concentration range of 0.5-100ng/mL, with a lower limit of quantitation of 0.5ng/mL. All validation parameters, including the inter-day, intra-day, matrix effect, recovery, and stability in rat plasma, were acceptable according to the biological method validation guidelines developed by the FDA (2001). This method was successfully applied to a pharmacokinetic study in rats; oral administration of 1mg/kg of rhodamine B yielded a time to maximum concentration (Tmax) of 1.3±0.4h and an elimination half-life of 8.8±1.4h, with a clearance of 229.7±19.4mL/h/kg. These pharmacokinetic results provide a constructive contribution to our understanding of the absorption mechanism of rhodamine B and support additional food safety evaluations. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Power of Orbitrap-based LC-high resolution-MS/MS for comprehensive drug testing in urine with or without conjugate cleavage or using dried urine spots after on-spot cleavage in comparison to established LC-MSn or GC-MS procedures.

    PubMed

    Michely, Julian A; Meyer, Markus R; Maurer, Hans H

    2018-01-01

    Reliable, sensitive, and comprehensive urine screening procedures by gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry (LC-MS) with low or high resolution (HR) are of high importance for drug testing, adherence monitoring, or detection of toxic compounds. Besides conventional urine sampling, dried urine spots are of increasing interest. In the present study, the power of LC-HR-MS/MS was investigated for comprehensive drug testing in urine with or without conjugate cleavage or using dried urine spots after on-spot cleavage in comparison to established LC-MS n or GC-MS procedures. Authentic human urine samples (n = 103) were split in 4 parts. One aliquot was prepared by precipitation (UP), one by UP with conjugate cleavage (UglucP), one spot on filter paper cards and prepared by on-spot cleavage followed by liquid extraction (DUSglucE), and one worked-up by acid hydrolysis, liquid-liquid extraction, and acetylation for GC-MS analysis. The 3 series of LC-HR-MS/MS results were compared among themselves, to corresponding published LC-MS n data, and to screening results obtained by conventional GC-MS. The reference libraries used for the 3 techniques contained over 4500 spectra of parent compounds and their metabolites. The number of all detected hits (770 drug intakes) was set to 100%. The LC-HR-MS/MS approach detected 80% of the hits after UP, 89% after UglucP, and 77% after DUSglucE, which meant over one-third more hits in comparison to the corresponding published LC-MS n results with ≤49% detected hits. The GC-MS approach identified 56% of all detected hits. In conclusion, LC-HR-MS/MS provided the best screening results after conjugate cleavage and precipitation. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Evaluation of Acrylamide in Food from China by a LC/MS/MS Method

    PubMed Central

    Chen, Yong-Hong; Xia, En-Qin; Xu, Xiang-Rong; Ling, Wen-Hua; Li, Sha; Wu, Shan; Deng, Gui-Fang; Zou, Zhi-Fei; Zhou, Jing; Li, Hua-Bin

    2012-01-01

    Acrylamide is potential carcinogenic compound that possesses neurotoxicity activity. In this study, the levels of acrylamide in 123 selected food samples from China was evaluated using a LC/MS/MS method. One hundred and fifteen (115) out of 123 samples showed positive levels of acrylamide in the range of 0.41 to 4,126.26 µg/kg. Generally, the highest acrylamide levels were found in fried products, such as potato, prawn strips and rice crust, with average values of 604.27, 341.40, and 201.51 µg/kg, respectively. Heated protein-rich food also showed some acrylamide content (ranging from 2.31 to 78.57 µg/kg). The results revealed that a potential acrylamide public health risk occurred in processed snacks, as well as the food consumed daily. This study supplied new information on acrylamide content of a variety of heat-treated foods from China. PMID:23202837

  19. Molecular cloning and characterization of the MsHSP17.7 gene from Medicago sativa L.

    PubMed

    Li, Zhen-Yi; Long, Rui-Cai; Zhang, Tie-Jun; Yang, Qing-Chuan; Kang, Jun-Mei

    2016-08-01

    Heat shock proteins (HSPs) are ubiquitous protective proteins that play crucial roles in plant development and adaptation to stress, and the aim of this study is to characterize the HSP gene in alfalfa. Here we isolated a small heat shock protein gene (MsHSP17.7) from alfalfa by homology-based cloning. MsHSP17.7 contains a 477-bp open reading frame and encodes a protein of 17.70-kDa. The amino acid sequence shares high identity with MtHSP (93.98 %), PsHSP17.1 (83.13 %), GmHSP17.9 (74.10 %) and SlHSP17.6 (79.25 %). Phylogenetic analysis revealed that MsHSP17.7 belongs to the group of cytosolic class II small heat shock proteins (sHSP), and likely localizes to the cytoplasm. Quantitative RT-PCR indicated that MsHSP17.7 was induced by heat shock, high salinity, peroxide and drought stress. Prokaryotic expression indicated that the salt and peroxide tolerance of Escherichia coli was remarkably enhanced. Transgenic Arabidopsis plants overexpressing MsHSP17.7 exhibited increased root length of transgenic Arabidopsis lines under salt stress compared to the wild-type line. The malondialdehyde (MDA) levels in the transgenic lines were significantly lower than in wild-type, although proline levels were similar between transgenic and wild-type lines. MsHSP17.7 was induced by heat shock, high salinity, oxidative stress and drought stress. Overexpression analysis suggests that MsHSP17.7 might play a key role in response to high salinity stress.

  20. An analytical approach based on ESI-MS, LC-MS and PCA for the quali-quantitative analysis of cycloartane derivatives in Astragalus spp.

    PubMed

    Napolitano, Assunta; Akay, Seref; Mari, Angela; Bedir, Erdal; Pizza, Cosimo; Piacente, Sonia

    2013-11-01

    Astragalus species are widely used as health foods and dietary supplements, as well as drugs in traditional medicine. To rapidly evaluate metabolite similarities and differences among the EtOH extracts of the roots of eight commercial Astragalus spp., an approach based on direct analyses by ESI-MS followed by PCA of ESI-MS data, was carried out. Successively, quali-quantitative analyses of cycloartane derivatives in the eight Astragalus spp. by LC-ESI-MS(n) and PCA of LC-ESI-MS data were performed. This approach allowed to promptly highlighting metabolite similarities and differences among the various Astragalus spp. PCA results from LC-ESI-MS data of Astragalus samples were in reasonable agreement with both PCA results of ESI-MS data and quantitative results. This study affords an analytical method for the quali-quantitative determination of cycloartane derivatives in herbal preparations used as health and food supplements. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. UPLC-MS/MS analysis for antioxidant components of Lycii Fructus based on spectrum-effect relationship.

    PubMed

    Zhang, Xian-Fei; Chen, Juan; Yang, Jun-Li; Shi, Yan-Ping

    2018-04-01

    Lycii Fructus is widely cultivated in the Northwest China. It is well-known for its antiaging effect in traditional Chinese medicines (TCMs), but the effective components are not clear. In this work, the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was used to study the antioxidant components of Lycii Fructus through analyzing the spectrum-effect relationship, and the positive correlation components with antioxidant activity were partially identified. The extractums of Lycii Fructus were adsorbed with macroporous resin, and then eluted with water and 30%, 60%, 90% ethanol in turn. The extract fraction eluted with 60% ethanol was determined as the best, and was taken for subsequent experiments. With the above separation method, UPLC fingerprints of thirty batches of Lycii Fructus (from different areas) were obtained, and thirty common peaks were selected through similarity analysis (SA). Combined with the data of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays, the spectrum-effect relationship was studied. The results showed that the main peaks with antioxidant activity were P14, P26, P8, and P21 for DPPH, and P26, P14, P21, and P19 for ABTS. Using the UPLC-MS/MS data, peaks P14, P19, P21, and P30 were respectively identified as chlorogenic acid, quercetin, kaempferol, and isorhamnetin, and then the results were confirmed through comparison with the standards and other references. Finally, their strong antioxidant activities were validated experimentally. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. An impulse-driven liquid-droplet deposition interface for combining LC with MALDI MS and MS/MS.

    PubMed

    Young, J Bryce; Li, Liang

    2006-03-01

    A simple and robust impulse-driven droplet deposition system was developed for off-line liquid chromatography matrix-assisted laser desorption ionization mass spectrometry (LC-MALDI MS). The system uses a solenoid operated with a pulsed voltage power supply to generate impulses that dislodge the hanging droplets from the LC outlet directly to a MALDI plate via a momentum transfer process. There is no contact between the LC outlet and the collection surface. The system is compatible with solvents of varying polarity and viscosity, and accommodates the use of hydrophobic and hydrophilic MALDI matrices. MALDI spots are produced on-line with the separation, and do not require further processing before MS analysis. It is shown that high quality MALDI spectra from 5 fmol of pyro-Glu-fibrinopeptide deposition after LC separation could be obtained using the device, indicating that there was no sample loss in the interface. To demonstrate the analytical performance of the system as a proteome analysis tool, a range of BSA digest concentrations covering about 3 orders of magnitude, from 5 fmol to 1 pmol, were analyzed by LC-MALDI quadrupole time-of-flight MS, yielding 6 and 57% amino acid sequence coverage, respectively. In addition, a complex protein mixture of an E. coli cell extract was tryptically digested and analyzed by LC-MALDI MS, resulting in the detection of a total of 409 unique peptides from 100 fractions of 15-s intervals.

  3. Development of an Advanced HPLC–MS/MS Method for the Determination of Carotenoids and Fat-Soluble Vitamins in Human Plasma

    PubMed Central

    Hrvolová, Barbora; Martínez-Huélamo, Miriam; Colmán-Martínez, Mariel; Hurtado-Barroso, Sara; Lamuela-Raventós, Rosa Maria; Kalina, Jiří

    2016-01-01

    The concentration of carotenoids and fat-soluble vitamins in human plasma may play a significant role in numerous chronic diseases such as age-related macular degeneration and some types of cancer. Although these compounds are of utmost interest for human health, methods for their simultaneous determination are scarce. A new high pressure liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) method for the quantification of selected carotenoids and fat-soluble vitamins in human plasma was developed, validated, and then applied in a pilot dietary intervention study with healthy volunteers. In 50 min, 16 analytes were separated with an excellent resolution and suitable MS signal intensity. The proposed HPLC–MS/MS method led to improvements in the limits of detection (LOD) and quantification (LOQ) for all analyzed compounds compared to the most often used HPLC–DAD methods, in some cases being more than 100-fold lower. LOD values were between 0.001 and 0.422 µg/mL and LOQ values ranged from 0.003 to 1.406 µg/mL, according to the analyte. The accuracy, precision, and stability met with the acceptance criteria of the AOAC (Association of Official Analytical Chemists) International. According to these results, the described HPLC-MS/MS method is adequately sensitive, repeatable and suitable for the large-scale analysis of compounds in biological fluids. PMID:27754400

  4. Development of an Advanced HPLC-MS/MS Method for the Determination of Carotenoids and Fat-Soluble Vitamins in Human Plasma.

    PubMed

    Hrvolová, Barbora; Martínez-Huélamo, Miriam; Colmán-Martínez, Mariel; Hurtado-Barroso, Sara; Lamuela-Raventós, Rosa Maria; Kalina, Jiří

    2016-10-14

    The concentration of carotenoids and fat-soluble vitamins in human plasma may play a significant role in numerous chronic diseases such as age-related macular degeneration and some types of cancer. Although these compounds are of utmost interest for human health, methods for their simultaneous determination are scarce. A new high pressure liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) method for the quantification of selected carotenoids and fat-soluble vitamins in human plasma was developed, validated, and then applied in a pilot dietary intervention study with healthy volunteers. In 50 min, 16 analytes were separated with an excellent resolution and suitable MS signal intensity. The proposed HPLC-MS/MS method led to improvements in the limits of detection (LOD) and quantification (LOQ) for all analyzed compounds compared to the most often used HPLC-DAD methods, in some cases being more than 100-fold lower. LOD values were between 0.001 and 0.422 µg/mL and LOQ values ranged from 0.003 to 1.406 µg/mL, according to the analyte. The accuracy, precision, and stability met with the acceptance criteria of the AOAC (Association of Official Analytical Chemists) International. According to these results, the described HPLC-MS/MS method is adequately sensitive, repeatable and suitable for the large-scale analysis of compounds in biological fluids.

  5. Beyond the initial 140 ms, lexical decision and reading aloud are different tasks: An ERP study with topographic analysis.

    PubMed

    Mahé, Gwendoline; Zesiger, Pascal; Laganaro, Marina

    2015-11-15

    Most of our knowledge on the time-course of the mechanisms involved in reading derived from electrophysiological studies is based on lexical decision tasks. By contrast, very few ERP studies investigated the processes involved in reading aloud. It has been suggested that the lexical decision task provides a good index of the processes occurring during reading aloud, with only late processing differences related to task response modalities. However, some behavioral studies reported different sensitivity to psycholinguistic factors between the two tasks, suggesting that print processing could differ at earlier processing stages. The aim of the present study was thus to carry out an ERP comparison between lexical decision and reading aloud in order to determine when print processing differs between these two tasks. Twenty native French speakers performed a lexical decision task and a reading aloud task with the same written stimuli. Results revealed different electrophysiological patterns on both waveform amplitudes and global topography between lexical decision and reading aloud from about 140 ms after stimulus presentation for both words and pseudowords, i.e., as early as the N170 component. These results suggest that only very early, low-level visual processes are common to the two tasks which differ in core processes. Taken together, our main finding questions the use of the lexical decision task as an appropriate paradigm to investigate reading processes and warns against generalizing its results to word reading. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. LC-MS/MS Peptide Mapping with Automated Data Processing for Routine Profiling of N-Glycans in Immunoglobulins

    NASA Astrophysics Data System (ADS)

    Shah, Bhavana; Jiang, Xinzhao Grace; Chen, Louise; Zhang, Zhongqi

    2014-06-01

    Protein N-Glycan analysis is traditionally performed by high pH anion exchange chromatography (HPAEC), reversed phase liquid chromatography (RPLC), or hydrophilic interaction liquid chromatography (HILIC) on fluorescence-labeled glycans enzymatically released from the glycoprotein. These methods require time-consuming sample preparations and do not provide site-specific glycosylation information. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) peptide mapping is frequently used for protein structural characterization and, as a bonus, can potentially provide glycan profile on each individual glycosylation site. In this work, a recently developed glycopeptide fragmentation model was used for automated identification, based on their MS/MS, of N-glycopeptides from proteolytic digestion of monoclonal antibodies (mAbs). Experimental conditions were optimized to achieve accurate profiling of glycoforms. Glycan profiles obtained from LC-MS/MS peptide mapping were compared with those obtained from HPAEC, RPLC, and HILIC analyses of released glycans for several mAb molecules. Accuracy, reproducibility, and linearity of the LC-MS/MS peptide mapping method for glycan profiling were evaluated. The LC-MS/MS peptide mapping method with fully automated data analysis requires less sample preparation, provides site-specific information, and may serve as an alternative method for routine profiling of N-glycans on immunoglobulins as well as other glycoproteins with simple N-glycans.

  7. Application of stored waveform ion modulation 2D-FTICR MS/MS to the analysis of complex mixtures.

    PubMed

    Ross, Charles W; Simonsick, William J; Aaserud, David J

    2002-09-15

    Component identification of complex mixtures, whether they are from polymeric formulations or combinatorial synthesis, by conventional MS/MS techniques generally requires component separation by chromatography or mass spectrometry. An automated means of acquiring simultaneous MS/MS data from a complex mixture without prior separation is obtained from stored waveform ion modulation (SWIM) two-dimensional FTICR MS/MS. The technique applies a series of SWIFT excitation waveforms whose frequency domain magnitude spectrum is a sinusoid increasing in frequency from one waveform to the next. The controlled dissociation of the precursor ions produces an associated modulation of the product ion abundances. Fourier transformation of these abundances reveals the encoded modulation frequency from which connectivities of precursor and product ions are observed. The final result is total assignment of product ions for each precursor ion in a mixture from one automated experiment. We demonstrated the applicability of SWIM 2D-FTICR MS/MS to two diverse samples of industrial importance. We characterized structured polyester oligomers and products derived from combinatorial synthesis. Fragmentation pathways identified in standard serial ion isolation MS/MS experiments were observed for trimethylolpropane/methyl hexahydrophthalic anhydride. A 20-component sample derived from combinatorial synthesis was fragmented, and the template ion along with another key fragment ion was identified for each of the 20 components.

  8. Decision making under uncertainty, therapeutic inertia, and physicians' risk preferences in the management of multiple sclerosis (DIScUTIR MS).

    PubMed

    Saposnik, Gustavo; Sempere, Angel Perez; Raptis, Roula; Prefasi, Daniel; Selchen, Daniel; Maurino, Jorge

    2016-05-04

    The management of multiple sclerosis (MS) is rapidly changing by the introduction of new and more effective disease-modifying agents. The importance of risk stratification was confirmed by results on disease progression predicted by different risk score systems. Despite these advances, we know very little about medical decisions under uncertainty in the management of MS. The goal of this study is to i) identify whether overconfidence, tolerance to risk/uncertainty, herding influence medical decisions, and ii) to evaluate the frequency of therapeutic inertia (defined as lack of treatment initiation or intensification in patients not at goals of care) and its predisposing factors in the management of MS. This is a prospective study comprising a combination of case-vignettes and surveys and experiments from Neuroeconomics/behavioral economics to identify cognitive distortions associated with medical decisions and therapeutic inertia. Participants include MS fellows and MS experts from across Spain. Each participant will receive an individual link using Qualtrics platform(©) that includes 20 case-vignettes, 3 surveys, and 4 behavioral experiments. The total time for completing the study is approximately 30-35 min. Case vignettes were selected to be representative of common clinical encounters in MS practice. Surveys and experiments include standardized test to measure overconfidence, aversion to risk and ambiguity, herding (following colleague's suggestions even when not supported by the evidence), physicians' reactions to uncertainty, and questions from the Socio-Economic Panel Study (SOEP) related to risk preferences in different domains. By applying three different MS score criteria (modified Rio, EMA, Prosperini's scheme) we take into account physicians' differences in escalating therapy when evaluating medical decisions across case-vignettes. The present study applies an innovative approach by combining tools to assess medical decisions with experiments from

  9. Development of a LC-MS/MS method to analyze 5-methoxy-N,N-dimethyltryptamine and bufotenine, and application to pharmacokinetic study

    PubMed Central

    Shen, Hong-Wu; Jiang, Xi-Ling; Yu, Ai-Ming

    2010-01-01

    Introduction 5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a psychoactive indolealkylamine substance that has been used for recreational purpose and may lead to fatal toxicity. While 5-MeO-DMT is mainly inactivated via deamination, it is O-demethylated to an active metabolite, bufotenine. Quantitation of 5-MeO-DMT and bufotenine is essential to understand the exposure to and the effects of drug and metabolite. This study, therefore, aimed to develop and validate a LC-MS/MS method for simultaneous analysis of 5-MeO-DMT and bufotenine in mouse serum. Methods A simple protein precipitation method coupled with an optimal gradient elution was used for sample preparation and separation. Detection of 5-MeO-DMT and bufotenine was accomplished using multiple reaction monitoring of m/z 219.2→174.2 and 205.2→160.2, respectively, in the positive ion mode. 5-Methyl-N,N-dimethyltrypamine (m/z 203.2→158.3) was used as internal standard for quantification. Accuracy and precision were determined after the analyses of quality control samples. Validated assay was then employed to determine drug and metabolite concentrations in serum samples collected from mice at different time points after intraperitoneal administration of 5-MeO-DMT (2 mg/kg). Results With a total run time of 9 min, 5-MeO-DMT and bufotenine were eluted at 2.8 and 5.6 min, respectively. The assay was linear over the range 0.90–5,890 ng/mL (1.12–7,360 pg on-column) for 5-MeO-DMT and 2.52–5,510 ng/mL (3.14–6,890 pg) for bufotenine. Intra- and inter-day precision and accuracy were within 15% for both analytes. The recovery of each analyte from 20 µL of serum containing 8.08, 72.7 and 655 ng/mL of 5-MeO-DMT and 7.56, 68.1 and 613 ng/mL of bufotenine was more than 75%. Pharmacokinetic analysis revealed that the systemic exposure (area under the curve) to metabolite bufotenine was about 1/14 of that to 5-MeO-DMT. Conclusion This LC-MS/MS method is a sensitive and reliable assay for quantitation of blood 5

  10. Development of a LC-MS/MS method to analyze 5-methoxy-N,N-dimethyltryptamine and bufotenine, and application to pharmacokinetic study.

    PubMed

    Shen, Hong-Wu; Jiang, Xi-Ling; Yu, Ai-Ming

    2009-04-01

    INTRODUCTION: 5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a psychoactive indolealkylamine substance that has been used for recreational purpose and may lead to fatal toxicity. While 5-MeO-DMT is mainly inactivated via deamination, it is O-demethylated to an active metabolite, bufotenine. Quantitation of 5-MeO-DMT and bufotenine is essential to understand the exposure to and the effects of drug and metabolite. This study, therefore, aimed to develop and validate a LC-MS/MS method for simultaneous analysis of 5-MeO-DMT and bufotenine in mouse serum. METHODS: A simple protein precipitation method coupled with an optimal gradient elution was used for sample preparation and separation. Detection of 5-MeO-DMT and bufotenine was accomplished using multiple reaction monitoring of m/z 219.2→174.2 and 205.2→160.2, respectively, in the positive ion mode. 5-Methyl-N,N-dimethyltrypamine (m/z 203.2→158.3) was used as internal standard for quantification. Accuracy and precision were determined after the analyses of quality control samples. Validated assay was then employed to determine drug and metabolite concentrations in serum samples collected from mice at different time points after intraperitoneal administration of 5-MeO-DMT (2 mg/kg). RESULTS: With a total run time of 9 min, 5-MeO-DMT and bufotenine were eluted at 2.8 and 5.6 min, respectively. The assay was linear over the range 0.90-5,890 ng/mL (1.12-7,360 pg on-column) for 5-MeO-DMT and 2.52-5,510 ng/mL (3.14-6,890 pg) for bufotenine. Intra- and inter-day precision and accuracy were within 15% for both analytes. The recovery of each analyte from 20 µL of serum containing 8.08, 72.7 and 655 ng/mL of 5-MeO-DMT and 7.56, 68.1 and 613 ng/mL of bufotenine was more than 75%. Pharmacokinetic analysis revealed that the systemic exposure (area under the curve) to metabolite bufotenine was about 1/14 of that to 5-MeO-DMT. CONCLUSION: This LC-MS/MS method is a sensitive and reliable assay for quantitation of blood 5-Me

  11. Analytical methods for multiresidue determination of sulfonamides and trimethoprim in meat and ground water samples by CE-MS and CE-MS/MS.

    PubMed

    Soto-Chinchilla, Jorge J; García-Campaña, Ana M; Gámiz-Gracia, Laura

    2007-11-01

    This paper presents two methods based on CZE-MS detection and CZE-MS/MS detection developed for the multiresidue determination of ten sulfonamides (sulfapyridine, sulfadoxin, sulfamethazine, sulfadimethoxine, sulfameter, sulfamerazine, sulfachlorpyridazine, sulfadiazine, sulfamethoxazole, and sulfamethizole) and a potentiator, trimethoprim (TMP), whose contents are regulated by the EU Council Regulation no. 2377/90 in animal edible tissues. Experimental designs were employed to optimize the electrospray conditions. MS/MS experiments using an IT as analyzer operating in multiple reaction monitoring (MRM) mode were carried out to achieve the minimum number of points according to the 2002/657/EC European Decision for unambiguous identification. The proposed procedures have been compared in terms of the performance characteristics and trueness. The limits of detection and quantification were in all cases lower than the maximum residue limits legislated for these compounds and the recoveries were satisfactory, being possible the application for their monitoring in foodstuff of animal origin and in environmental samples, allowing the determination of sulfonamides and TMP residues in meat and in superficial water in the low microg/L range.

  12. Prognostic value of high-field proton magnetic resonance spectroscopy in patients presenting with clinically isolated syndromes suggestive of multiple sclerosis.

    PubMed

    Wattjes, Mike P; Harzheim, Michael; Lutterbey, Götz G; Bogdanow, Manuela; Schmidt, Stephan; Schild, Hans H; Träber, Frank

    2008-02-01

    The aim of this study was to determine the prognostic value of metabolic alterations in the normal-appearing white matter (NAWM) of patients presenting with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS) with special regard to the prediction of conversion to definite MS. Using a 3T whole-body MR system, a multisequence conventional MRI protocol and single-voxel proton MR spectroscopy (PRESS, repetition time 2000 ms, echo times 38 ms and 140 ms) of the parietal NAWM were performed in 25 patients presenting with CIS at baseline and in 20 controls. Absolute concentrations of N-acetyl-aspartate (tNAA), myo-inositol (Ins), choline (Cho) and creatine (tCr) as well as metabolite ratios were determined. Follow-up including neurological assessment and conventional MRI was performed 3-4 and 6-7 months after the initial event. Nine patients converted to definite MS during the follow-up period. Compared to controls, those patients who converted to MS also showed significantly lower tNAA concentrations in the NAWM (-13.4%, P = 0.002) whereas nonconverters (-6.5%, P = 0.052) did not. The Ins concentration was 20.2% higher in the converter group and 1.9% higher in the nonconverter group, but these differences did not reach significance. No significant differences could be observed for tCr and Cho in either patient group. Axonal damage at baseline in patients presenting with CIS was more prominent in those who subsequently converted to definite MS in the short term follow-up, indicating that tNAA might be a sufficient prognostic marker for patients with a higher risk of conversion to early definite MS.

  13. UHPLC-MS/MS phenolic profiling and in vitro antioxidant activities of Inula graveolens (L.) Desf.

    PubMed

    Silinsin, Muzaffer; Bursal, Ercan

    2018-06-01

    Inula graveolens (L.) Desf. is an annual aromatic herb which has various uses on alternative medicine in many region of the world. In this study, antioxidant activities of ethanol and water extracts of the plant leaves were determined by in vitro DPPH method and phenolic composition of the plant sample was determined by LC-MS/MS analysis. The results showed that chlorogenic acid, quinic acid, hyperoside, protocatechuic acid and quercetin were the major phenolic compounds among the 27 standard compounds. The significant antioxidant capacity of the plant might be related with the high abundance of phenolic compounds.

  14. An Artifact in LC-MS/MS Measurement of Glutamine and Glutamic Acid: In-Source Cyclization to Pyroglutamic Acid

    PubMed Central

    2015-01-01

    Advances in metabolomics, particularly for research on cancer, have increased the demand for accurate, highly sensitive methods for measuring glutamine (Gln) and glutamic acid (Glu) in cell cultures and other biological samples. N-terminal Gln and Glu residues in proteins or peptides have been reported to cyclize to pyroglutamic acid (pGlu) during liquid chromatography (LC)-mass spectrometry (MS) analysis, but cyclization of free Gln and Glu to free pGlu during LC-MS analysis has not been well-characterized. Using an LC-MS/MS protocol that we developed to separate Gln, Glu, and pGlu, we found that free Gln and Glu cyclize to pGlu in the electrospray ionization source, revealing a previously uncharacterized artifact in metabolomic studies. Analysis of Gln standards over a concentration range from 0.39 to 200 μM indicated that a minimum of 33% and maximum of almost 100% of Gln was converted to pGlu in the ionization source, with the extent of conversion dependent on fragmentor voltage. We conclude that the sensitivity and accuracy of Gln, Glu, and pGlu quantitation by electrospray ionization-based mass spectrometry can be improved dramatically by using (i) chromatographic conditions that adequately separate the three metabolites, (ii) isotopic internal standards to correct for in-source pGlu formation, and (iii) user-optimized fragmentor voltage for acquisition of the MS spectra. These findings have immediate impact on metabolomics and metabolism research using LC-MS technologies. PMID:24892977

  15. An artifact in LC-MS/MS measurement of glutamine and glutamic acid: in-source cyclization to pyroglutamic acid.

    PubMed

    Purwaha, Preeti; Silva, Leslie P; Hawke, David H; Weinstein, John N; Lorenzi, Philip L

    2014-06-17

    Advances in metabolomics, particularly for research on cancer, have increased the demand for accurate, highly sensitive methods for measuring glutamine (Gln) and glutamic acid (Glu) in cell cultures and other biological samples. N-terminal Gln and Glu residues in proteins or peptides have been reported to cyclize to pyroglutamic acid (pGlu) during liquid chromatography (LC)-mass spectrometry (MS) analysis, but cyclization of free Gln and Glu to free pGlu during LC-MS analysis has not been well-characterized. Using an LC-MS/MS protocol that we developed to separate Gln, Glu, and pGlu, we found that free Gln and Glu cyclize to pGlu in the electrospray ionization source, revealing a previously uncharacterized artifact in metabolomic studies. Analysis of Gln standards over a concentration range from 0.39 to 200 μM indicated that a minimum of 33% and maximum of almost 100% of Gln was converted to pGlu in the ionization source, with the extent of conversion dependent on fragmentor voltage. We conclude that the sensitivity and accuracy of Gln, Glu, and pGlu quantitation by electrospray ionization-based mass spectrometry can be improved dramatically by using (i) chromatographic conditions that adequately separate the three metabolites, (ii) isotopic internal standards to correct for in-source pGlu formation, and (iii) user-optimized fragmentor voltage for acquisition of the MS spectra. These findings have immediate impact on metabolomics and metabolism research using LC-MS technologies.

  16. mzDB: A File Format Using Multiple Indexing Strategies for the Efficient Analysis of Large LC-MS/MS and SWATH-MS Data Sets*

    PubMed Central

    Bouyssié, David; Dubois, Marc; Nasso, Sara; Gonzalez de Peredo, Anne; Burlet-Schiltz, Odile; Aebersold, Ruedi; Monsarrat, Bernard

    2015-01-01

    The analysis and management of MS data, especially those generated by data independent MS acquisition, exemplified by SWATH-MS, pose significant challenges for proteomics bioinformatics. The large size and vast amount of information inherent to these data sets need to be properly structured to enable an efficient and straightforward extraction of the signals used to identify specific target peptides. Standard XML based formats are not well suited to large MS data files, for example, those generated by SWATH-MS, and compromise high-throughput data processing and storing. We developed mzDB, an efficient file format for large MS data sets. It relies on the SQLite software library and consists of a standardized and portable server-less single-file database. An optimized 3D indexing approach is adopted, where the LC-MS coordinates (retention time and m/z), along with the precursor m/z for SWATH-MS data, are used to query the database for data extraction. In comparison with XML formats, mzDB saves ∼25% of storage space and improves access times by a factor of twofold up to even 2000-fold, depending on the particular data access. Similarly, mzDB shows also slightly to significantly lower access times in comparison with other formats like mz5. Both C++ and Java implementations, converting raw or XML formats to mzDB and providing access methods, will be released under permissive license. mzDB can be easily accessed by the SQLite C library and its drivers for all major languages, and browsed with existing dedicated GUIs. The mzDB described here can boost existing mass spectrometry data analysis pipelines, offering unprecedented performance in terms of efficiency, portability, compactness, and flexibility. PMID:25505153

  17. Quantification of Free Phenytoin by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS).

    PubMed

    Peat, Judy; Frazee, Clint; Garg, Uttam

    2016-01-01

    Phenytoin (diphenylhydantoin) is an anticonvulsant drug that has been used for decades for the treatment of many types of seizures. The drug is highly protein bound and measurement of free-active form of the drug is warranted particularly in patients with conditions that can affect drug protein binding. Here, we describe a LC/MS/MS method for the measurement of free phenytoin. Free drug is separated by ultrafiltration of serum or plasma. Ultrafiltrate is treated with acetonitrile containing internal standard phenytoin d-10 to precipitate proteins. The mixture is centrifuged and supernatant is injected onto LC-MS-MS, and analyzed using multiple reaction monitoring. This method is linear from 0.1 to 4.0 μg/mL and does not demonstrate any significant ion suppression or enhancement.

  18. Study of vortex-assisted MSPD and LC-MS/MS using alternative solid supports for pharmaceutical extraction from marketed fish.

    PubMed

    Hertzog, Gabriel I; Soares, Karina L; Caldas, Sergiane S; Primel, Ednei G

    2015-06-01

    A procedure based on vortex-assisted matrix solid-phase dispersion (MSPD) for the extraction of 15 pharmaceuticals from fish samples with determination by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was validated. Florisil, C18, diatomaceous earth, chitin, and chitosan were evaluated as solid supports. Best results were obtained with 0.5 g of diatomaceous earth, 0.5 g of sodium sulfate, and 5 mL of methanol. Analytical recoveries ranged from 58 to 128 % with relative standard deviation (RSD) lower than 15 %. Limit of quantification (LOQ) values for the 15 compounds ranged from 5 to 1000 ng g(-1). The method under investigation has shown to be a simple and fast extraction tool with minimum instrumentation and low amount of reagent, resulting in method low cost. Besides, alternative materials, such as chitin and chitosan, which were applied to the dispersion step for the first time, were found to be interesting alternatives.

  19. Comparison of preferences of healthcare professionals and MS patients for attributes of disease-modifying drugs: A best-worst scaling.

    PubMed

    Kremer, Ingrid E H; Evers, Silvia M A A; Jongen, Peter J; Hiligsmann, Mickaël

    2018-02-01

    The choice between disease-modifying drugs (DMDs) for the treatment of multiple sclerosis (MS) becomes more often a shared decision between the patient and the neurologist and MS nurse. This study aimed to assess which DMD attributes are most important for the healthcare professionals in selecting a DMD for a patient. Subsequently, within this perspective, the neurologists' and nurses' perspectives were compared. Lastly, the healthcare professionals' perspective was compared with the patients' perspective to detect any differences that may need attention in the communication about DMDs. A best-worst scaling (BWS) was conducted among 27 neurologists and 33 MS nurses treating patients with MS to determine the importance of 27 DMD attributes. These attributes were identified through three focus groups with MS patients in a previous study (N=19). Relative importance scores (RISs) were estimated for each attribute. Multivariable linear regression analyses were used to compare the different perspectives. According to the neurologists and nurses, safety of the DMD was the most important DMD attribute in the treatment decision, closely followed by effect on disability progression, quality of life and relapse rate. Patients with MS agreed with the importance of the last three attributes, but valued safety significantly lower (b=-2.59, P<.001). This study suggests that, overall, neurologists and nurses regard the same DMD attributes as important as MS patients with the notable exception of safety. This study provides valuable information for the development of interventions to support shared decision making and highlights which attributes of DMDs may need additional attention. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.

  20. Misleading measures in Vitamin D analysis: A novel LC-MS/MS assay to account for epimers and isobars

    PubMed Central

    2011-01-01

    Background Recently, the accuracies of many commercially available immunoassays for Vitamin D have been questioned. Liquid chromatography tandem mass spectrometry (LC- MS/MS) has been shown to facilitate accurate separation and quantification of the major circulating metabolite 25-hydroxyvitamin-D3 (25OHD3) and 25-hydroxyvitamin-D2 (25OHD2) collectively termed as 25OHD. However, among other interferents, this method may be compromised by overlapping peaks and identical masses of epimers and isobars, resulting in inaccuracies in circulating 25OHD measurements. The aim of this study was to develop a novel LC-MS/MS method that can accurately identify and quantitate 25OHD3 and 25OHD2 through chromatographic separation of 25OHD from its epimers and isobars. Methods A positive ion electrospray ionisation (ESI) LC-MS/MS method was used in the Multiple Reaction Monitoring (MRM) mode for quantification. It involved i) liquid-liquid extraction, ii) tandem columns (a high resolution ZORBAX C18 coupled to an ULTRON chiral, with guard column and inlet filter), iii) Stanozolol-D3 as internal standard, and iv) identification via ESI and monitoring of three fragmentation transitions. To demonstrate the practical usefulness of our method, blood samples were collected from 5 healthy male Caucasian volunteers; age range 22 to 37 years and 25OHD2, 25OHD3 along with co-eluting epimers and analogues were quantified. Results The new method allowed chromatographic separation and quantification of 25OHD2, 25OHD3, along with 25OHD3 epimer 3-epi-25OHD3 and isobars 1-α-hydroxyvitamin-D3 (1αOHD3), and 7-α-hydroxy-4-cholesten-3-one (7αC4). The new assay was capable of detecting 0.25 ng/mL of all analytes in serum. Conclusions To our knowledge, this is the first specific, reliable, reproducible and robust LC-MS/MS method developed for the accurate detection of 25OHD (Vitamin D). The method is capable of detecting low levels of 25OHD3 and 25OHD2 together with chromatographic separation from