Mass Spectrometry

Source: www.ncbi.nlm.nih.gov --- 2 days ago
Related Articles Capillary electrophoresis-Mass Spectrometry in urinary proteome analysis: current applications and future developments. Anal Bioanal Chem. 2008 Aug 15; Authors: Metzger J, Schanstra JP, Mischak H The development of noninvasive methods for diagnosis and prognosis of many diseases still remains a challenging task in clinical medicine. In recent years, protein separation and detection techniques have been refined such that they allow proteome screening of biological fluids with good reproducibility, accuracy, and real-time performance. The advancements in this field resulted in the initiation and conduction of many clinical studies aimed towards defining sensitive and selective biomarkers for disease or a pathological condition. In this review, we focus on the description of the state of the art proteomic platforms established or adapted to use urine as sample source for biomarker discovery. In the second part of this review, we will give an overview of recent clinical studies that used capillary electrophoresis-Mass Spectrometry (CE-MS) in urinary proteomics/peptidomics. Owing to its fast and accurate one-step screening method CE-MS allows resolution of the urinary small molecular weight proteome in high-throughput mode. This makes CE-MS well suited for use in large proteomic studies. The fact that urinary proteomic studies are not restricted to renal and urological disorders, but also enable assessment of systemic disea ...

Source: www.ncbi.nlm.nih.gov --- 7 days ago
Related Articles Integration of continuous-flow accelerator Mass Spectrometry with chromatography and Mass-selective detection. Anal Chem. 2008 Jul 1;80(13):5079-85 Authors: Flarakos J, Liberman RG, Tannenbaum SR, Skipper PL Physical combination of an accelerator Mass Spectrometry (AMS) instrument with a conventional gas chromatograph-Mass spectrometer (GC/MS) is described. The resulting hybrid instrument (GC/MS/AMS) was used to monitor Mass chromatograms and radiochromatograms simultaneously when (14)C-labeled compounds were injected into the gas chromatograph. Combination of the two instruments was achieved by splitting the column effluent and directing half to the Mass spectrometer and half to a flow-through CuO reactor in line with the gas-accepting AMS ion source. The reactor converts compounds in the GC effluent to CO2 as required for function of the ion source. With cholesterol as test compound, the limits of quantitation were 175 pg and 0.00175 dpm injected. The accuracy achieved in analysis of five nonzero calibration standards and three quality control standards, using cholesterol-2,2,3,4,4,6-d6 as injection standard, was 100 +/- 11.8% with selected ion monitoring and 100 +/- 16% for radiochromatography. Respective values for interday precision were 1.0-3.2 and 22-32%. Application of GC/MS/AMS to a current topic of interest was demonstrated in a model metabolomic study in which cultured primary hepatocytes were given [(14)C] ...

Source: www.ncbi.nlm.nih.gov --- 5 days ago
Related Articles Determination of fumonisins B1 and B2 in corn by liquid chromatography/Mass Spectrometry with immunoaffinity column cleanup: single-laboratory method validation. J AOAC Int. 2008 May-Jun;91(3):598-606 Authors: Senyuva HZ, Ozcan S, Cimen D, Gilbert J A single-laboratory method validation was conducted to establish the effectiveness of an immunoaffinity column cleanup procedure followed by liquid chromatography/Mass Spectrometry (LCIMS) for the determination of fumonisins B1 and B2 (FBI + FB2) in corn. The test portion is extracted with acetonitrile-methanol-water (25 + 25 + 50). The extract is filtered, diluted with phosphate-buffered saline solution, and applied to an immunoaffinity column. FB1 + FB2 are removed with methanol and directly determined by reversed-phase LC with MS detection using selected-ion monitoring of 2 characteristic ions in each case. Test portions of blank corn samples were spiked with a mixture of FB1 + FB2 to give total levels of 200 and 500 ng/g, respectively. Recoveries of both FB1 and FB2 from spiked samples averaged 90.4-101%. Based on results for spiked raw corn (triplicates at 2 levels), the relative standard deviation for repeatability ranged from 2.8 to 7.1%. The accuracy of the method was demonstrated by analysis of Food Analysis Performance Assessment Scheme (FAPAS) test material. The method was also applied to a small survey of processed corn products such as corn chips, cornflakes, a ...

Source: www.ncbi.nlm.nih.gov --- 6 days ago
Related Articles Activation of complement system in adult T-cell leukemia (ATL) occurs mainly through lectin pathway: A serum proteomic approach using Mass Spectrometry. Cancer Lett. 2008 Aug 6; Authors: Ishida YI, Yamashita K, Sasaki H, Takajou I, Kubuki Y, Morishita K, Tsubouchi H, Okayama A Adult T-cell leukemia (ATL) is a fatal malignancy caused by infection with human T lymphotropic virus type-1 (HTLV-1). To search for a new biomarker of ATL, we analyzed sera from ATL patients using 1ys. The spectral comparison of ATL patients with HTLV-1 carriers and healthy volunteers showed that the intensities of five peaks (1779, 1866, 2022, 4467, and 8930m/z) were significantly increased in ATL, while those of four peaks (4067, 4151, 8130, and 8597m/z) were decreased. From these differentially expressed peaks, we chose peaks of 1779, 1866, and 2022m/z as biomarker candidates of ATL. MS/MS ion search using tandem Mass Spectrometry and immunoprecipitation assay using anti-C3 antibody showed that factors derived from these candidate peaks were identified as C3f, which is a component of the complement system and a fragment of complement C3. These results indicate that the complement system was activated in ATL. Further analysis of markers specific to the activation pathways (classical, alternative, and lectin pathways) in the complement system showed that the serum concentration of the marker of the lectin pathway was significantly higher in AT ...

Source: www.ncbi.nlm.nih.gov --- 4 days ago
Related Articles Evaluation of a deuterium-labeled internal standard for the measurement of sirolimus by high-throughput HPLC electrospray ionization tandem Mass Spectrometry. Clin Chem. 2008 Aug;54(8):1386-9 Authors: O'Halloran S, Ilett KF BACKGROUND: Matrix effects in HPLC-electrospray ionization-tandem Mass Spectrometry (HPLC-ESI-MS/MS)1 can cause differences in the ionization of an internal standard (IS) compared with the analyte of interest. Unless sample cleanup or chromatographic conditions eliminate or minimize ion suppression or enhancement, variability in interpatient matrices may cause erroneous results. A stable isotope-labeled IS can be used to minimize analytical interpatient variation. METHODS: We used protein precipitation and HPLC-ESI-MS/MS to quantify sirolimus (SIR) with both desmethoxyrapamycin (DMR) and deuterium-labeled sirolimus (SIR-d(3)) as the IS to analyze a range of whole-blood and extraction-matrix samples, and to estimate recovery, matrix effects, process efficiency, and interpatient variation. We also analyzed a series of blood samples from 72 patients taking SIR, including external proficiency-testing samples, with these ISs. RESULTS: The range of interpatient assay imprecision (CV) values for the SIR assay was consistently lower with SIR-d(3) (2.7%-5.7%) than with DMR (7.6%-9.7%). The results obtained with the 2 different ISs for the patient samples showed a linear relationship, but the results were hig ...

Source: www.ncbi.nlm.nih.gov --- 14 hours ago
Related Articles Immunoglobulin derived depositions in the nervous system: novel Mass Spectrometry application for protein characterization in formalin-fixed tissues. Lab Invest. 2008 Aug 18; Authors: Rodriguez FJ, Gamez JD, Vrana JA, Theis JD, Giannini C, Scheithauer BW, Parisi JE, Lucchinetti CF, Pendlebury WW, Bergen HR, Dogan A Proteinaceous deposits are occasionally encountered in surgically obtained biopsies of the nervous system. Some of these are amyloidomas, although the precise nature of other cases remains uncertain. We studied 13 cases of proteinaceous aggregates in clinical specimens of the nervous system. Proteins contained within laser microdissected areas of interest were identified from tryptic peptide sequences by liquid chromatography-electrospray tandem Mass Spectrometry (LC-MS/MS). Immunohistochemical studies for immunoglobulin heavy and light chains and amyloidogenic proteins were performed in all cases. Histologically, the cases were classified into three groups: 'proteinaceous deposit not otherwise specified' (PDNOS) (n=6), amyloidoma (n=5), or 'intracellular crystals' (n=2). LC-MS/MS demonstrated the presence of lambda, but not kappa, light chain as well as serum amyloid P in all amyloidomas. lambda-Light-chain immunostaining was noted in amyloid (n=5), although demonstrable monotypic lymphoplasmacytic cells were seen in only one case. Conversely, in PDNOS kappa, but not lambda, was evident in five cases, both ...

Source: news.thomasnet.com --- 2 days ago
Used to power Mass Spectrometry microchannel plate detectors and electron multiplier applications, MCP Series features 3 kV, 330 µA output section that is floating and isolated to 16 kV. This facilitates referencing of output to voltage potentials other than ground and also provides inherent polarity reversibility. Customer-provided analog 0-10 Vdc programming signal will adjust supply from 0-100% of rated output voltage, and corresponding voltage feedback monitor signal is provided. This story is related to the following: Electrical Equipment and Systems Sponsored by: Globtek Inc. - Your Power Partner...For Over 20 Years! Search for suppliers of: Switching Power Supplies | Modular Power Supplies | Laboratory Power Supplies | High Voltage Power Supplies | Programmable Power Supplies | Ion Beam Power Supplies | Electron Beam (EB) Power Supplies ...

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Nature Aug 18 2008 4:52PM GMT ...

Source: pubs.acs.org --- 4 days ago
Amala Dass, George R. Dubay, Christina A. Fields-Zinna, and Royce W. Murray Web Release Date: Sat, 16 Aug 2008 00:00:00 EDT (Accelerated Article) DOI: 10.1021/ac801259j ...

Source: pubs.acs.org --- 10 days ago
Till Gruendling, Michael Guilhaus, and Christopher Barner-Kowollik Web Release Date: Sat, 9 Aug 2008 00:00:00 EDT (Article) DOI: 10.1021/ac800591j ...

Source: pubs.acs.org --- 8 days ago
Mohammadreza Shariatgorji, Juan Astorga-Wells, Hans Jornvall, and Leopold L. Ilag Web Release Date: Tue, 12 Aug 2008 00:00:00 EDT (Article) DOI: 10.1021/ac800877k ...

Source: pubs.acs.org --- 5 days ago
Hendrik Neubert, Christopher Grace, Klaus Rumpel, and Ian James Web Release Date: Fri, 15 Aug 2008 00:00:00 EDT (Article) DOI: 10.1021/ac8005439 ...

Source: pubs.acs.org --- 7 days ago
J. S. Mellors, V. Gorbounov, R. S. Ramsey, and J. M. Ramsey Web Release Date: Wed, 13 Aug 2008 00:00:00 EDT (Article) DOI: 10.1021/ac800428w ...

Source: pubs.acs.org --- 7 days ago
Cornelius T. Martha, Niels Elders, Johannes G. Krabbe, Jeroen Kool, Wilfried M. A. Niessen, Romano V. A. Orru, and Hubertus Irth Web Release Date: Wed, 13 Aug 2008 00:00:00 EDT (Article) DOI: 10.1021/ac801003h ...

Source: pubs.acs.org --- 10 days ago
Jean-Philippe Godin, Gérard Hopfgartner, and Laurent Fay Web Release Date: Sat, 9 Aug 2008 00:00:00 EDT (Technical Note) DOI: 10.1021/ac8004204 ...

Source: pubs.acs.org --- 10 days ago
Prahlad K. Rao, G. Marcela Rodriguez, Issar Smith, and Qingbo Li Web Release Date: Sat, 9 Aug 2008 00:00:00 EDT (Article) DOI: 10.1021/ac800288t ...

Source: www.earthtimes.org --- 3 days ago
AMSTERDAM, The Netherlands - Bruker Daltonics today is showcasing several new high performance Mass Spectrometry products and applications for proteomics at the 7th HUPO World Congress 2008: maXis ...

Source: www.topix.com --- 3 days ago
McKusick-Nathans Institute of Genetic Medicine and the Departments of Biological Chemistry, Pathology and Oncology, Johns Hopkins University, Baltimore, Maryland 21205, Institute of Bioinformatics, ... ...