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MALDI and matrix

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https://www.readbyqxmd.com/read/27914002/phenotypic-and-genotypic-characterization-of-bacteriocinogenic-enterococci-against-clostridium-botulinum
#1
Awad A Shehata, Reda Tarabees, Shereen Basiouni, Mahmoud Gamil, Ahmed S Kamal, Monika Krüger
The present study aimed to characterize Enterococcus faecalis (n = -6) and Enterococcus faecium (n = 1) isolated from healthy chickens to find a novel perspective probiotic candidate that antagonize Clostridium botulinum types A, B, D, and E. The isolated enterococci were characterized based on phenotypic properties, PCR, and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF). The virulence determinants including hemolytic activity on blood agar, gelatinase activity, sensitivity to vancomycin, and presence of gelatinase (gelE) and enterococcal surface protein (esp) virulence genes were investigated...
December 2, 2016: Probiotics and Antimicrobial Proteins
https://www.readbyqxmd.com/read/27909779/structure-performance-relationships-of-phenyl-cinnamic-acid-derivatives-as-maldi-ms-matrices-for-sulfatide-detection
#2
Suparna Tambe, Henning Blott, Annabelle Fülöp, Nils Spang, Dirk Flottmann, Stefan Bräse, Carsten Hopf, Hans-Dieter Junker
A key aspect for the further development of matrix-assisted laser desorption ionization (MALDI)-mass spectrometry (MS) is a better understanding of the working principles of MALDI matrices. To address this issue, a chemical compound library of 59 structurally related cinnamic acid derivatives was synthesized. Potential MALDI matrices were evaluated with sulfatides, a class of anionic lipids which are abundant in complex brain lipid mixtures. For each matrix relative mean S/N ratios of sulfatides were determined against 9-aminoacridine as a reference matrix using negative ion mass spectrometry with 355 and 337 nm laser systems...
December 1, 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27906399/unusual-reactivity-of-dithiol-protected-clusters-in-comparison-to-monothiol-protected-clusters-studies-using-ag51-bdt-19-tpp-3-and-ag29-bdt-12-tpp-4
#3
Atanu Ghosh, Debasmita Ghosh, Esma Khatun, Papri Chakraborty, Thalappil Pradeep
We report the synthesis and unique reactivity of a new green dithiol protected cluster (DTPC), Ag51(BDT)19(TPP)3 (BDT and TPP are 1,3-benzenedithiol and triphenylphosphine, respectively). The cluster composition was confirmed by electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrometric studies as well as by other supporting data. Surprisingly, the chemical reactivity between this DTPC and Au25(SR)18 involves only metal ion exchange in Au25(SR)18 without any ligand exchange, while reactions between monothiol protected clusters (MTPCs) show both metal and ligand exchange, an example being the reaction between Ag25DMBT18 and Au25PET18 (where DMBT and PET are 2,4-dimethylbenzenethiol and phenylethanethiol, respectively)...
December 1, 2016: Nanoscale
https://www.readbyqxmd.com/read/27905002/disseminated-candidiasis-in-a-young-previously-healthy-dog-and-review-of-literature
#4
Nicole Willems, Dirk J Houwers, Yvette M Schlotter, Bart Theelen, Teun Boekhout
BACKGROUND: The reports on disseminated candidiasis in dogs so far describe at least one predisposing factor. This case report, however, highlights candidiasis in a dog without any known predisposition. PATIENT: A 1.5-year-old intact female Hovawart dog was presented with subcutaneous nodules and polyuria/polydipsia. An excisional biopsy revealed a chronic pyogranulomatous and necrotizing inflammation with mycotic structures. The patient became febrile and lethargic, and developed lameness...
November 30, 2016: Mycopathologia
https://www.readbyqxmd.com/read/27904505/composition-and-biological-activities-of-the-aqueous-extracts-of-three-scleractinian-corals-from-the-mexican-caribbean-pseudodiploria-strigosa-porites-astreoides-and-siderastrea-siderea
#5
Alejandro García-Arredondo, Alejandra Rojas-Molina, César Ibarra-Alvarado, Fernando Lazcano-Pérez, Roberto Arreguín-Espinosa, Judith Sánchez-Rodríguez
BACKGROUND: Scleractinian corals (stony corals) are the most abundant reef-forming cnidarians found in coral reefs throughout the world. Despite their abundance and ecological importance, information about the diversity of their toxins and their biological activities is very scarce. In this study, the chemical composition and the biological activities of the aqueous extracts of Pseudodiploria strigosa, Porites astreoides and Siderastrea siderea, three scleractinian corals from the Mexican Caribbean, have been assessed for the first time...
2016: Journal of Venomous Animals and Toxins Including Tropical Diseases
https://www.readbyqxmd.com/read/27891120/two-major-clades-of-bradyrhizobia-dominate-symbiotic-interactions-with-pigeonpea-in-fields-of-c%C3%A3-te-d-ivoire
#6
Romain K Fossou, Dominik Ziegler, Adolphe Zézé, François Barja, Xavier Perret
In smallholder farms of Côte d'Ivoire, particularly in the northeast of the country, Cajanus cajan (pigeonpea) has become an important crop because of its multiple beneficial facets. Pigeonpea seeds provide food to make ends meet, are sold on local markets, and aerial parts serve as forage for animals. Since it fixes atmospheric nitrogen in symbiosis with soil bacteria collectively known as rhizobia, C. cajan also improves soil fertility and reduces fallow time. Yet, seed yields remain low mostly because farmers cannot afford chemical fertilizers...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27890679/evaluation-of-non-supervised-maldi-mass-spectrometry-imaging-combined-with-microproteomics-for-glioma-grade-iii-classification
#7
Emilie Le Rhun, Marie Duhamel, Maxence Wisztorski, Jean-Pascal Gimeno, Fahed Zairi, Fabienne Escande, Nicolas Reyns, Firas Kobeissy, Claude-Alain Maurage, Michel Salzet, Isabelle Fournier
An integrated diagnosis using molecular features is recommended in the 2016 World Health Organization (WHO) classification. Our aim was to explore non-targeted molecular classification using MALDI mass spectrometry imaging (MALDI MSI) associated to microproteomics in order to classify anaplastic glioma by integration of clinical data. We used fresh-frozen tissue sections to perform MALDI MSI of proteins based on their digestion peptides after in-situ trypsin digestion of the tissue sections and matrix deposition by micro-spraying...
November 23, 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27889877/maldi-tof-ms-meets-wgs-in-a-vre-outbreak-investigation
#8
S Schlebusch, G R Price, R L Gallagher, V Horton-Szar, L D H Elbourne, P Griffin, D J Venter, S O Jensen, S J Van Hal
The use of MALDI-TOF MS (matrix-assisted laser desorption/ ionization-time of flight mass spectrometry) and WGS (whole genome sequencing) has been described for identification and strain relatedness determination. We describe the complementary use of MALDI-TOF MS and WGS in a VRE (vancomycin-resistant enterococci) outbreak investigation, and discuss some of the challenges with defining strain similarity across these two platforms. Although both assays indicated multiple clusters involved in the outbreak of vancomycin resistant Enterococcus faecium isolates from positive blood cultures of four haematology-oncology patients, the small cohort and discrepancies between findings indicate the limitations of MALDI-TOF MS and the cautious interpretation of MALDI-TOF MS dendrograms during outbreaks...
November 26, 2016: European Journal of Clinical Microbiology & Infectious Diseases
https://www.readbyqxmd.com/read/27885266/electrospray-deposition-device-used-to-precisely-control-the-matrix-crystal-to-improve-the-performance-of-maldi-msi
#9
Shilei Li, Yangyang Zhang, Jian'an Liu, Juanjuan Han, Ming Guan, Hui Yang, Yu Lin, Shaoxiang Xiong, Zhenwen Zhao
MALDI MSI has been recently applied as an innovative tool for detection of molecular distribution within a specific tissue. MALDI MSI requires deposition of an organic compound, known as matrix, on the tissue of interest to assist analyte desorption and ionization, in which the matrix crystal homogeneity and size greatly influence the imaging reproducibility and spatial resolution in MALDI MSI. In this work, a homemade electrospray deposition device was developed for deposition of matrix in MALDI MSI. The device could be used to achieve 1 μm homogeneous matrix crystals in MALDI MSI analysis...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27883030/spatial-quantitation-of-drugs-in-tissues-using-liquid-extraction-surface-analysis-mass-spectrometry-imaging
#10
John G Swales, Nicole Strittmatter, James W Tucker, Malcolm R Clench, Peter J H Webborn, Richard J A Goodwin
Liquid extraction surface analysis mass spectrometry imaging (LESA-MSI) has been shown to be an effective tissue profiling and imaging technique, producing robust and reliable qualitative distribution images of an analyte or analytes in tissue sections. Here, we expand the use of LESA-MSI beyond qualitative analysis to a quantitative analytical technique by employing a mimetic tissue model previously shown to be applicable for MALDI-MSI quantitation. Liver homogenate was used to generate a viable and molecularly relevant control matrix for spiked drug standards which can be frozen, sectioned and subsequently analyzed for the generation of calibration curves to quantify unknown tissue section samples...
November 24, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27879638/structural-investigation-of-cell-wall-xylan-polysaccharides-from-the-leaves-of-algerian-argania-spinosa
#11
Kadda Hachem, Céline Faugeron, Meriem Kaid-Harche, Vincent Gloaguen
Xylan-type polysaccharides were isolated from the leaves of Argania spinosa (L.) Skeels collected in the Tindouf area (southwestern Algeria). Xylan fractions were obtained by sequential alkaline extractions and purified on Sepharose CL-4B. The xylan structure was investigated by enzymatic hydrolysis with an endo-β(1→4)-xylanase followed by chromatography of the resulting fragments on Biogel P2, characterization by sugar analysis and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS )...
November 21, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27873216/prognostic-metabolite-biomarkers-for-soft-tissue-sarcomas-discovered-by-mass-spectrometry-imaging
#12
Sha Lou, Benjamin Balluff, Arjen H G Cleven, Judith V M G Bovée, Liam A McDonnell
Metabolites can be an important read-out of disease. The identification and validation of biomarkers in the cancer metabolome that can stratify high-risk patients is one of the main current research aspects. Mass spectrometry has become the technique of choice for metabolomics studies, and mass spectrometry imaging (MSI) enables their visualization in patient tissues. In this study, we used MSI to identify prognostic metabolite biomarkers in high grade sarcomas; 33 high grade sarcoma patients, comprising osteosarcoma, leiomyosarcoma, myxofibrosarcoma, and undifferentiated pleomorphic sarcoma were analyzed...
November 21, 2016: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/27873003/localization-of-ergot-alkaloids-in-sclerotia-of-claviceps-purpurea-by-matrix-assisted-laser-desorption-ionization-mass-spectrometry-imaging
#13
Julian Dopstadt, Simeon Vens-Cappell, Lisa Neubauer, Paul Tudzynski, Benedikt Cramer, Klaus Dreisewerd, Hans-Ulrich Humpf
The fungus Claviceps purpurea produces highly toxic ergot alkaloids and accumulates these in the hardened bodies of fungal mycelium. These so-called sclerotia, or ergot bodies, replace the crop seed of infected plants, which can include numerous important food- and feedstuff such as rye and wheat. While several studies have explored details of the infection process and development of ergot bodies, little information is available on the spatial distribution of the mycotoxins in the sclerotia. Here we used matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) at a lateral resolution of 35 μm to visualize the distribution of two representative alkaloids, ergocristine and ergometrine, produced by Ecc93 and Gal 310 variants of C...
November 21, 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27870135/independent-assessment-of-matrix-assisted-laser-desorption-ionization-mass-spectrometry-maldi-ms-sample-preparation-quality-effect-of-sample-preparation-on-maldi-ms-of-synthetic-polymers
#14
Pieter C Kooijman, Sander Kok, Maarten Honing
RATIONALE: Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides detailed and in-depth information about the molecular characteristics of synthetic polymers. To obtain the most accurate results the sample preparation parameters should be chosen to suit the sample and the aim of the experiment. Because the underlying principles of MALDI are still not fully known, a priori determination of optimal sample preparation protocols is often not possible. METHODS: Employing an automated sample preparation quality assessment method recently presented by us we quantified the sample preparation quality obtained using various sample preparation protocols...
November 21, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/27869666/gingival-crevicular-fluid-as-a-novel-potential-source-of-biomarkers-distinguishes-pubertal-from-post-pubertal-subjects
#15
Xi Wen, Yan Gu, Feng Chen
Detection of pubertal growth peak is vital in orthodontic treatment timing and planning. Gingival crevicular fluid (GCF) contains abundant proteins from different sources and has been proven to be an ideal source of biomarkers. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) is an advanced technique that can detect low-molecular-weight peptides with high sensitivity and resolution. The aim of this research was to identify novel candidate biomarkers in GCF to help the diagnosis of pubertal growth peak by MALDI-TOF/MS...
November 17, 2016: Diagnostics
https://www.readbyqxmd.com/read/27869126/caenorhabditis-elegans-as-a-model-system-to-study-post-translational-modifications-of-human-transthyretin
#16
Andrea Henze, Thomas Homann, Isabelle Rohn, Michael Aschner, Christopher D Link, Burkhard Kleuser, Florian J Schweigert, Tanja Schwerdtle, Julia Bornhorst
The visceral protein transthyretin (TTR) is frequently affected by oxidative post-translational protein modifications (PTPMs) in various diseases. Thus, better insight into structure-function relationships due to oxidative PTPMs of TTR should contribute to the understanding of pathophysiologic mechanisms. While the in vivo analysis of TTR in mammalian models is complex, time- and resource-consuming, transgenic Caenorhabditis elegans expressing hTTR provide an optimal model for the in vivo identification and characterization of drug-mediated oxidative PTPMs of hTTR by means of matrix assisted laser desorption/ionization - time of flight - mass spectrometry (MALDI-TOF-MS)...
November 21, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27868065/comparative-proteomic-analysis-of-light-induced-mycelial-brown-film-formation-in-lentinula-edodes
#17
Li Hua Tang, Qi Tan, Da Peng Bao, Xue Hong Zhang, Hua Hua Jian, Yan Li, Rui Heng Yang, Ying Wang
Light-induced brown film (BF) formation by the vegetative mycelium of Lentinula edodes is important for ensuring the quantity and quality of this edible mushroom. Nevertheless, the molecular mechanism underlying this phenotype is still unclear. In this study, a comparative proteomic analysis of mycelial BF formation in L. edodes was performed. Seventy-three protein spots with at least a twofold difference in abundance on two-dimensional electrophoresis (2DE) maps were observed, and 52 of them were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF/MS)...
2016: BioMed Research International
https://www.readbyqxmd.com/read/27866257/detection-of-methicillin-resistant-staphylococcus-aureus-using-phage-amplification-combined-with-matrix-assisted-laser-desorption-ionization-mass-spectrometry
#18
Jon C Rees, John R Barr
Antibiotic resistance continues to contribute significantly to morbidity and mortality across the world. Developing new tests for antibiotic-resistant bacteria is a core action to combat resistant infections. We describe a method that uses phage amplification detection (PAD) combined with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to rapidly identify Staphylococcus aureus and determine phenotypic susceptibility to cefoxitin. Samples tested for S. aureus are incubated together with bacteriophage in the presence and absence of cefoxitin and subjected to rapid trypsin digestion followed by MALDI-MS analysis...
November 19, 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27864634/reactions-of-aquacobalamin-and-cob-ii-alamin-with-chlorite-and-chlorine-dioxide
#19
Ilia A Dereven'kov, Nikita I Shpagilev, László Valkai, Denis S Salnikov, Attila K Horváth, Sergei V Makarov
Reactions of aquacobalamin (H2O-Cbl(III)) and its one-electron reduced form (cob(II)alamin, Cbl(II)) with chlorite (ClO2(-)) and chlorine dioxide (ClO 2(•) ) were studied by conventional and stopped-flow UV-Vis spectroscopies and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). ClO2(-) does not react with H2O-Cbl(III), but oxidizes Cbl(II) to H2O-Cbl(III) as a major product and corrin-modified species as minor products. The proposed mechanism of chlorite reduction involves formation of OCl(-) that modifies the corrin ring during the course of reaction with Cbl(II)...
November 19, 2016: Journal of Biological Inorganic Chemistry: JBIC
https://www.readbyqxmd.com/read/27863949/imipenem-avibactam-a-novel-combination-for-the-rapid-detection-of-carbapenemase-activity-in-enterobacteriaceae-and-acinetobacter-baumannii-by-matrix-assisted-laser-desorption-ionization-time-of-flight-mass-spectrometry
#20
Marina Oviaño, Germán Bou
In the present study, we propose a novel matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for detecting carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii. For this, we analyzed a series of 131 isolates. Among them, a total of 115 Enterobacteriaceae: 79 of them carrying a carbapenemase enzyme (15blaKPC, 7blaNDM, 11blaIMP, 12blaVIM, and 34blaOXA-48) and 16 A. baumannii isolates: 15 of them carrying carbapenemases (10blaOXA-23, 2blaOXA-58, 2blaOXA-24, and 1blaOXA-237)...
October 18, 2016: Diagnostic Microbiology and Infectious Disease
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