Search results for "SAC"

Alpha-defensins secreted by dysplastic granulocytes inhibit the differentiation of monocytes in chronic myelomonocytic leukemia.

2010

Abstract Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic disorder that occurs in elderly patients. One of the main diagnostic criteria is the accumulation of heterogeneous monocytes in the peripheral blood. We further explored this cellular heterogeneity and observed that part of the leukemic clone in the peripheral blood was made of immature dysplastic granulocytes with a CD14−/CD24+ phenotype. The proteome profile of these cells is dramatically distinct from that of CD14+/CD24− monocytes from CMML patients or healthy donors. More specifically, CD14−/CD24+ CMML cells synthesize and secrete large amounts of alpha-defensin 1-3 (HNP1-3). Recombinant HNPs inhibit macrophage co…

Dynamic Preisach Hysteresis Model for Magnetostrictive Materials for Energy Application

2013

Synthesis of glycopeptides and neoglycoproteins containing the fucosylated linkage region of N-glycoproteins.

1994

Abstract N-Glycoproteins fucosylated in the core region occur in tumor membranes and virus envelopes. Partial structures of such N-glycoproteins containing fucosylated chitobiosyl asparagine conjugates were synthesized using the allyloxycarbonyl (Aloc) and the tert-butyl ester protecting groups in the peptide portion. As the α-fucosidic bond of the conjugates revealed to be very sensitive to acids when carrying ether-type protecting groups, a method for exchanging the protecting groups of the fucose portion of saccharides was developed. Conjugates containing O-acetyl protected fucose proved to be stable against acids used in glycopeptide syntheses. These methods were applied in the synthesi…

Dissolution mechanism of crystalline cellulose in H3PO4 as assessed by high-field NMR spectroscopy and Fast Field Cycling NMR relaxometry

2009

Many processes have been proposed to produce glucose as a substrate for bacterial fermentation to obtain bioethanol. Among others, cellulose degradation appears as the most convenient way to achieve reliable amounts of glucose units. In fact, cellulose is the most widespread biopolymer, and it is considered also as a renewable resource. Due to extended intra- and interchain hydrogen bonds that provide a very efficient packing structure, however, cellulose is also a very stable polymer, the degradation of which is not easily achievable. In the past decade, researchers enhanced cellulose reactivity by increasing its solubility in many solvents, among which concentrated phosphoric acid (H(3)PO…

The effect of salt content on the structure of iota-carrageenan systems: Na-23 DQF NMR and rheological studies

2009

International audience; 23Na NMR spectroscopy has been used to study the effects of Na+ ion concentrations on the structure of 1% (w/w) iota-carrageenan systems, a natural gelling polysaccharide used as a thickener in the food industry. Rheological and 23Na T1 relaxation time measurements revealed that gel formation correlates with decreases in ion mobility over the range of 0-3% (w/w) sodium content. 23Na single-quantum (SQ) and double-quantum-filtered (DQF) NMR experiments performed on these systems provided evidence for a bound sodium ion fraction in a specifically ordered environment. These results have allowed us to propose a model for the carrageenan gelation mechanism in the presence…

Dynamics of the biosynthesis of methylursubin in plant cells employing in vivo 13CNMR without labelling.

1995

Abstract In vivo NMR experiments with a digital 600 MHz instrument, exploiting the natural abundance of 13C, allowed us for the first time to follow the biosynthesis of the newly detected glycoside, methylursubin ( 4- methoxyphenyl -O-β- d -primeveroside ), from 4-methoxyphenol through the intermediate methylarbutin in cell suspensions of the Indian medical plant, Rauwolfia serpentina. The metabolic dynamics indicate that, within 48 hr, 4-methoxyphenol is almost completely converted into the primeveroside, methylursubin. Because of the higher sensitivity at 150.9 MHz compared to that at 100.6 MHz, measuring times could be reduced to 1.5 hr. This allows detailed monitoring of the conversion …

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 .

Triterpene Saponins from Tupidanthus calyptratus

2001

Five new bisdesmosidic saponins (1--5) were isolated from the aerial parts of Tupidanthus calyptratus. Their structures were determined by (1)H--(1)H correlation spectroscopy (COSY, TOCSY, ROESY) and (1)H--(13)C correlation (HSQC, HMBC) NMR experiments, FABMS, and chemical data.

Two New Glycosides from Astragalus caprinus

2001

A new glycoside of flavonol (1) and a new glycoside of a cycloartane-type triterpene (2) were isolated from the leaves and the roots of Astragalus caprinus, respectively. Their structures were elucidated in turn by spectroscopic data interpretation as 3-O-[[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)][beta-D-apiofuranosyl(1-->2)]]-beta-D-galactopyranosyl kaempferol (1) and 3-O-(beta-D-xylopyranosyl)-24-O-(beta-D-glucopyranosyl)-20,25-epoxycycloartane-3beta,6alpha,16beta,24alpha-tetrol (2).

The possible association of clusterin fucosylation changes with male fertility disorders

2021

AbstractIn the seminal plasma (n = 118) and serum (n = 90) clusterin (CLU) the fucosylation and the expression of selected fucosyltransferases (FUTs) were analyzed. Samples from infertile men were divided into groups based on the results of the standard semen analysis: normozoospermic (N), teratozoospermic (T), asthenoteratozoospermic (AT) and oligoasthenoteratozoospermic (OAT). The CLU fucosylation was analyzed using lectin-ELISAs with biotinylated lectins specific to α1,3-, α1,2-linked antennary fucose, and α1,6-linked core fucose (LTA, UEA, and LCA, respectively). The concentrations of FUT3 and FUT4, reflecting the expression of Le oligosaccharide structures, were measured using ELISA te…