Search results for "oligosaccharides"

Water Dynamics at the Solid-Liquid Interface to Unveil the Textural Features of Synthetic Nanosponges.

2020

A Fast-Field-Cycling NMR investigation was carried out on a set of polyurethane cyclodextrin nanosponges, in order to gain information on their textural properties, which have been proven to be quite difficult to assess by means of ordinary porosimetric techniques. Experiments were performed on both dry and wet samples, in order to evaluate the behavior of the “non-exchangeable” C-bound 1H nuclei, as well as the one of the mobile protons belonging to the skeletal hydroxyl groups and the water molecules. The results acquired for the wet samples accounted for the molecular mobility of water molecules within the channels of the nanosponge network, leading back to the possible pore size distrib…

An ex vivo model of the rat trachea to study the effect of inhalable toxic compounds

1996

Different cell culture and organ systems are used to evaluate the physiological responses of the airways to the effects of carcinogenic [e.g., benzo(a)pyrene] and anticarcinogenic (e.g., retinoids) compounds on cellular growth and differentiation. However, in contrast to in vivo conditions dissociated epithelial cells or tracheal ring cultures are covered with medium. Therefore, we developed an ex vivo perfusion model enabling evaluation of morphology and metabolism of different compounds under near-physiological conditions. The trachea was surrounded with culture medium and perfused with air by means of a small animal respirator. To test the viability of the system under various experiment…

Core Oligosaccharide of Plesiomonas shigelloides PCM 2231 (Serotype O17) Lipopolysaccharide — Structural and Serological Analysis

2013

The herein presented complete structure of the core oligosaccharide of lipopolysaccharide (LPS) P. shigelloides Polish Collection of Microorganisms (PCM) 2231 (serotype O17) was investigated by (1)H, (13)C NMR spectroscopy, mass spectrometry, chemical analyses and serological methods. The core oligosaccharide is composed of an undecasaccharide, which represents the second core type identified for P. shigelloides serotype O17 LPS. This structure is similar to that of the core oligosaccharide of P. shigelloides strains 302-73 (serotype O1) and 7-63 (serotype O17) and differs from these only by one sugar residue. Serological screening of 55 strains of P. shigelloides with the use of serum agai…

Apical transport of osteopontin is independent of N-glycosylation and sialylation.

2002

Studies of how epithelial surface polarity into apical and basolateral domains is generated and maintained have proposed that carbohydrate modifications serve as apical targeting signals for proteins by interacting with lectin sorters. However, the experimental evidence in support of N-glycans, O-glycans and sialic acids mediating apical transport is still very controversial. This could be partly due to the fact that in most studies exogenously expressed proteins were analysed. One has, therefore, examined the role of carbohydrate moieties in apical targeting of the endogenous secretory protein osteopontin in MDCK cells. It was found, however, that sorting of osteopontin does not require N-…

Chemoenzymatic Synthesis of Functional Sialyl LewisX Mimetics with a Heteroaromatic Core

2014

Functional mimetics of the sialyl Lewis(X) tetrasaccharide were prepared by the enzymatic sialylation of a 1,3-diglycosylated indole and a glycosyl azide, which was subsequently transformed into a 1,4-diglycosylated 1,2,3-triazole, by using the trans-sialidase of Trypanosoma cruzi. These compounds inhibited the binding of E-, L-, and P-selectin-coated nanoparticles to polyacrylamide-bound sialyl-Lewis(X) -containing neighboring sulfated tyrosine residues (sTyr/sLe(X) -PAA) at low or sub-millimolar concentrations. Except for E-selectin, the mimetics showed higher activities than the natural tetrasaccharide.

Structural analysis of the lipid A isolated from Hafnia alvei 32 and PCM 1192 lipopolysaccharides[S]

2010

Hafnia alvei, a Gram-negative bacterium, is an opportunistic pathogen associated with mixed hospital infections, bacteremia, septicemia, and respiratory diseases. The majority of clinical symptoms of diseases caused by this bacterium have a lipopolysaccharide (LPS, endotoxin)-related origin. The lipid A structure affects the biological activity of endotoxins predominantly. Thus, the structure of H. alvei lipid A was analyzed for the first time. The major form, asymmetrically hexa-acylated lipid A built of beta-D-GlcpN4P-(1-->6)-alpha-D-GlcpN1P substituted with (R)-14:0(3-OH) at N-2 and O-3, 14:0(3-(R)-O-12:0) at N-2', and 14:0(3-(R)-O-14:0) at O-3', was identified by ESI-MS(n) and MALDI-tim…

Synthesis of tumor-associated glycopeptide antigens for the development of tumor-selective vaccines

2004

In contrast to normal cells, the glycoprotein profile on epithelial tumor cells is distinctly altered. Due to an incomplete formation of the glycan side-chains resulting from a premature sialylation, additional peptide epitopes become accessible to the immune system in mucin-type glycoproteins on tumor cells. These tumor-associated structure alterations constitute the basis for a selective immunological attack on cancer cells. For the construction of immunostimulating antigens, glycopeptide partial structures from the mucins MUC1 and MUC4 carrying the tumor-associated sialyl-T(N), alpha2,6-sialyl-T and alpha2,3-sialyl-T antigens have been synthesized. Employing different linkers such as the…

Total Synthesis of the Glycopeptide Recognition Domain of the P-Selectin Glycoprotein Ligand 1

2008

Multiple reaction monitoring for identification and quantification of oligosaccharides in legumes using a triple quadrupole mass spectrometer.

2022

Raffinose family oligosaccharides are non-digestible compounds considered as dietary prebiotics with health-related properties. Hence, it is important to develop highly specific methods for their determination. An analytical method is developed in this study for oligosaccharide identification and quantification using liquid chromatography-tandem mass spectrometry equipped with a triple quadrupole analyser operating in Multiple Reaction Monitoring mode. Raffinose, stachyose and verbascose are separated in a 10-minute run and the method is validated over a broad concentration range, showing good linearity, accuracy, precision and high sensitivity. A low-cost, short eco-friendly procedure for …

Effects of preemptive analgesia with intravenous acetaminophen on postoperative pain relief in patients undergoing third molar surgery: a prospective…

2020

Background The efficacy of preemptive analgesia in managing postoperative pain remains controversial. The aim of this study was to compare the efficacy of intravenous (IV) acetaminophen administered before or immediately after the surgical extraction of an impacted mandibular third molar. Material and Methods This prospective randomized clinical trial included 120 patients. The patients were assigned to one of three groups: the preoperative-treatment group (pre-group), which received 1000 mg of IV acetaminophen 20 min before surgery; the postoperative-treatment group (post-group), which received 1000 mg of IV acetaminophen after surgery; the no-treatment group (control-group), which did not…