Search results for "matrix-assisted laser"
showing 10 items of 151 documents
Serological identification of HSP105 as a novel non-Hodgkin lymphoma therapeutic target.
2011
Abstract We reported that the clinical efficacy of dendritic cell–based vaccination is strongly associated with immunologic responses in relapsed B-cell non-Hodgkin lymphoma (B-NHL) patients. We have now investigated whether postvaccination antibodies from responders recognize novel shared NHL-restricted antigens. Immunohistochemistry and flow cytometry showed that they cross-react with allogeneic B-NHLs at significantly higher levels than their matched prevaccination samples or nonresponders' antibodies. Western blot analysis of DOHH-2 lymphoma proteome revealed a sharp band migrating at approximately 100 to 110 kDa only with postvaccine repertoires from responders. Mass spectrometry ident…
Revisited BIA-MS combination: Entire "on-a-chip" processing leading to the proteins identification at low femtomole to sub-femtomole levels
2008
International audience; We present the results of a study in which biomolecular interaction analysis (BIA, Biacore 2000) was combined with mass spectrometry (MS) using entire "on-a-chip" procedure. Most BIA-MS studies included an elution step of the analyte prior MS analysis. Here, we report a low-cost approach combining Biacore analysis with homemade chips and MS in situ identification onto the chips without elution step. First experiments have been made with rat serum albumin to determine the sensitivity and validation of the concept has been obtained with an antibody/antigen couple. Our "on-a-chip" procedure allowed complete analysis by MS-MS of the biochip leading to protein identificat…
Response of the oxygen sensor NreB to air in vivo: Fe-S-containing NreB and apo-NreB in aerobically and anaerobically growing Staphylococcus carnosus.
2009
ABSTRACT The sensor kinase NreB from Staphylococcus carnosus contains an O 2 -sensitive [4Fe-4S] 2+ cluster which is converted by O 2 to a [2Fe-2S] 2+ cluster, followed by complete degradation and formation of Fe-S-less apo-NreB. NreB·[2Fe-2S] 2+ and apoNreB are devoid of kinase activity. NreB contains four Cys residues which ligate the Fe-S clusters. The accessibility of the Cys residues to alkylating agents was tested and used to differentiate Fe-S-containing and Fe-S-less NreB. In a two-step labeling procedure, accessible Cys residues in the native protein were first labeled by iodoacetate. In the second step, Cys residues not labeled in the first step were alkylated with the fluorescent…
Chitosomes loaded with cranberry proanthocyanidins attenuate the bacterial lipopolysaccharide-induced expression of iNOS and COX-2 in raw 264.7 macro…
2009
Chitosan binds to negatively charged soy lecithin liposomes by an electrostatic interaction driven by its positively charged amino group. This interaction allows stable covered vesicles (chitosomes) to be developed as a suitable targeted carrier and controlled release system. This study investigated the effect of chitosomes on the activation of cranberry proanthocyanidins (PAC) in Raw 264.7 macrophages. Chitosomes were characterized according to size, zeta potential, PAC-loading, and release properties. Results showed an increase in the net positive charge and size of the liposomes as the concentration of chitosan was increased, suggesting an effective covering of the vesicles by means of e…
Comparison of two methods skipping cell lysis and protein extraction for identification of bacteria from blood cultures by matrix-assisted laser deso…
2019
ABSTRACT Objective Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) is widely used for fast identification of bacteria from blood cultures (BC). We compared the performance of two procedures, one including a pre-enrichment step in brain heart infusion and the other a direct method using vacutainer separator gel tubes (DI), for identification of bacteria from blood cultures by MALDI-TOF MS. Material and methods We first prepared a training set of 20 simulated bacteremia specimens, including 10 Gram-negative and 10 Gram-positive species. A total of 145 non-consecutive BCs flagged as positive (68 Gram-negative rods, and 77 Gram-positive cocci) were pr…
MALDI-TOF mass spectrometry identification of filamentous fungi in the clinical laboratory.
2014
Pôle MERS F. Dalle; International audience; This study aimed to validate the effectiveness of a standardised procedure for the MALDI-TOF mass spectrometry (MS)-based identification on a large sample of filamentous fungi routinely identified in university hospitals' laboratories. Non-dermatophyte filamentous fungi prospectively isolated in the routine activity of five teaching hospitals in France were first identified by conventional methods in each laboratory and then by MS in one centre. DNA sequence-based identification resolved discrepancies between both methods. In this study, of the 625 analysed filamentous fungi of 58 species, 501 (80%) and 556 (89%) were correctly identified by conve…
A Multicentre Pilot Study of a Two-Tier Newborn Sickle Cell Disease Screening Procedure with a First Tier Based on a Fully Automated MALDI-TOF MS Pla…
2019
The reference methods used for sickle cell disease (SCD) screening usually include two analytical steps: a first tier for differentiating haemoglobin S (HbS) heterozygotes, HbS homozygotes and β-thalassemia from other samples, and a confirmatory second tier. Here, we evaluated a first-tier approach based on a fully automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) platform with automated sample processing, a laboratory information management system and NeoSickle® software for automatic data interpretation. A total of 6701 samples (with high proportions of phenotypes homozygous (FS) or heterozygous (FAS) for the inherited genes for sickle h…
Squaric acid mediated chemoselective PEGylation of proteins: reactivity of single-step-activated α-amino poly(ethylene glycol)s.
2012
The covalent attachment of poly(ethylene glycol) (PEG) to therapeutically active proteins (PEGylation) has become an important method to deal with the pharmacological difficulties of these polypeptides, such as short body-residence times and immunogenicity. However, the derivatives of PEG used for PEGylation lack further functional groups that would allow the addition of targeting or labeling moieties. Squaric acid diethyl ester was used for the chemoselective single-step activation of poly(ethylene glycol)s into the respective ester amides. The resultant selective protein-reactive poly(ethylene glycol)s were investigated with respect to their selectivity towards amino acid residues in bovi…
Triplet-triplet energy transfer controlled by the donor-acceptor distance in rigidly held palladium-containing cofacial bisporphyrins.
2005
Eleven new complexes, including mono-, heterobi-, and homobimetallic cofacial bisporphyrins, (Pd)H 2 DPS, (M)H 2 DPX, (M)H 2 DPB, (PdZn)DPS, (PdZn)DPX, (Pt) 2 DPX, (M) 2 DPB (M=Pd, Pt), and (Pt)P (DPS 4 - = 4,6-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]dibenzothiophene tetraanion, DPX 4 - = 4,5-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]-9,9-dimethylxanthene tetraanion, DPB 4 - =1,8-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]biphenylene tetraanion, P 2 - = 5-phenyl-2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrin dianion) have been synthesized and characterized. The photophysical properties of the donor (M)P (M=Pd or Pt, P= porphy…
Novel O-antigen of Hafnia alvei PCM 1195 lipopolysaccharide with a teichoic acid-like structure
2009
Abstract The lipopolysaccharide (LPS) of Hafnia alvei strain PCM 1195 was obtained by the hot phenol/water method. The O-specific polysaccharide was released by mild acidic hydrolysis and isolated by gel filtration. The structure of the O-specific polysaccharide was investigated by 1 H, 13 C, and 31 P NMR spectroscopy, MALDI-TOF MS, and GC–MS, accompanied by monosaccharide and methylation analysis. It was concluded that the O-specific polysaccharide is composed of a hexasaccharide repeating units interlinked with a phosphate group: {→4-α- d -Glc p -(1→3)-α- l - Fuc p NAc-(1→3)-[α- d -Glc p -(1→4)]-α- d -Glc p NAc-(1→3)-α- l - Fuc p NAc-(1→4)-α- d -Glc p -(1→P} n .