Search results for " molecule"
showing 10 items of 1523 documents
Application of X-ray microanalysis to study of the expression of endothelial adhesion molecules on human umbilical vein endothelial cells in vitro
1994
A semi-quantitative procedure is described, which allows the evaluation of expression levels of endothelial adhesion molecules on cultured human umbilical vein endothelial cells (HUVEC) using energy dispersive X-ray microanalysis (EDX). As a model two adhesion molecules, E-selection (CD62E; ELAM-1/endothelial leukocyte adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1; CD54), were localized by the use of the silver-enhancement colloidal gold method after stimulation of HUVEC with endotoxin lipopolysaccharide (LPS), tumour necrosis factor (TNF) or a phorbol ester (PMA). The analysis was performed in a scanning electron microscope (SEM) at an accelerating voltage of 15 kV wit…
Préparation de liposomes fonctionnels pour l’encapsulation de composés bioactifs ou de sondes moléculaires fluorescentes pour l’imagerie cellulaire
2016
At ICMUB Institute, SUV liposomes have been used to achieve fluorophore encapsulation (subphtalocyanine) for cellular imaging [1] and have been bioconjugated to a peptide (bombesin) to achieve site-specificity, thanks to the structural modification of cholesterol, a component of the liposome, upon introduction of a reactive function. Hence, such liposomes fonctionnalised on the outer face may react with the terminal function of the peptide. Upon purification of the liposome by FPLC a 15 % encapsulation rate was measured by UV/Vis and attempted by ICP. The (outer) diameter of the liposomes (dDLS and dMET) ranged between 20 and 60 nm depending on the type of function or substituents on the ou…
Polysialic acid can mediate membrane interactions by interacting with phospholipids
2009
Polysialic acid (polySia) is expressed on the surface of neural cells, neuroinvasive bacterial cells and several tumor cells. PolySia chains attached to NCAM can influence both trans interactions between membranes of two cells and cis interactions. Here, we report on the involvement of phospholipids in regulation of membrane interactions by polySia. The pH at the surface of liposomes, specific molecular area of phosphatidylcholine molecules, phase transition of DPPC bilayers, cyclic voltammograms of BLMs, and electron micrographs of phosphatidylcholine vesicles were studied after addition of polysialic acid free in solution. The results indicate that polySia chains can associate with phosph…
Photoinduced chemiluminescence of pharmaceuticals
2005
Abstract A screening test for the forward development of chemiluminescence systems able to determine pharmaceutical compounds is reported. The test is based on the on-line photodegradation of the drugs by using a photoreactor consisting of 697 cm × 0.5 mm PTFE tubing helically coiled around an 8 W low-pressure mercury lamp. Photodegraded pharmaceuticals are detected by direct chemiluminescence of the resulting photofragments and their subsequent reaction with potassium permanganate in sulphuric acid medium as oxidant. The screening comprised 97 compounds with different molecular structures and relevant members of the most important families of pharmaceuticals are tested (amino acids, carbox…
Sphingosine-1-phosphate increases human alveolar epithelial IL-8 secretion, proliferation and neutrophil chemotaxis
2009
Sphingosine-1-phosphate (S1P) has been presented recently as a pro-inflammatory agent in the airway epithelium since S1P levels are increased in bronchoalveolar lavage fluid of human asthmatics. However, the effects of S1P over the alveolar epithelium and neutrophil interactions are poorly understood. Here, we show that S1P increased interleukin 8 (IL-8) gene expression and protein secretion and proliferation in alveolar epithelial cells A549 at physiological concentrations (1 microM). At the same time, S1P increased intracellular Ca2+ concentration (potency 17.91 microM, measured by epifluorescence microscopy), phospholipase D (PLD) activity (measured by chemiluminiscence method) and extra…
Analysis of cell-free human alpha1 integrin with a monoclonal antibody to the I-domain: detection in ocular fluid and function as an adhesion substra…
2002
The alpha1 beta1 integrin, an inserted (1) domain containing collagen receptor, is expressed in the cell surface membrane of normal and malignant cells, and may play a role in their migration through tissues or in metastatic spread. Here we report that a functional anti-human alpha1beta1 integrin monoclonal antibody (mAb) (1B3.1) directly and specifically binds plastic bound recombinant human alpha1 I-domain protein containing the collagen binding site. Detection was diminished by acidification of the I-domain protein but was enhanced by increasing concentrations of Mg2+ cation. Furthermore, we detected binding of the mAb to proteins from the ocular fluids of 6 patients, with the highest co…
Biochemical and Immunological implications of Lutein and Zeaxanthin
2021
Throughout history, nature has been acknowledged for being a primordial source of various bioactive molecules in which human macular carotenoids are gaining significant attention. Among 750 natural carotenoids, lutein, zeaxanthin and their oxidative metabolites are selectively accumulated in the macular region of living beings. Due to their vast applications in food, feed, pharmaceutical and nutraceuticals industries, the global market of lutein and zeaxanthin is continuously expanding but chemical synthesis, extraction and purification of these compounds from their natural repertoire e.g., plants, is somewhat costly and technically challenging. In this regard microbial as well as microalga…
Requirement of caveolae microdomains in extracellular signal-regulated kinase and focal adhesion kinase activation induced by endothelin-1 in primary…
1999
Endothelin-1 (ET-1) mitogenic activity in astrocytes is mediated by the activation of the extracellular signal-regulated kinase (ERK) pathway together with the Rho-dependent activation of the focal adhesion kinase (FAK) pathway. To clarify the mechanisms responsible for the coordinate activation of both pathways in the ET-1 signal propagation, the involvement of caveolae microdomains, suggested to play a role in signal transduction, was evaluated. In this study, it is reported that caveolae of primary astrocytes are enriched in endothelin receptor (ETB-R). Furthermore, signaling molecules such as the adaptor proteins Shc and Grb2, and the small G protein Rho, also reside within these microd…
Signal transduction pathways of the epidermal growth factor receptor in colorectal cancer and their inhibition by small molecules.
2012
While prognostic factors can help to classify the standard risk of subpopulations of patients with the same tumor entity, it is still not possible to predict the response of individual patients to specific therapies. The reason for such wide variation in cancer therapy responses remains largely unknown. The field of chemotherapy is currently undergoing a paradigm shift from classical cytotoxic chemotherapy to targeted therapy in order to kill tumor cells more efficiently with fewer side effects on normal tissue. In the present review, we focus on colorectal carcinoma, which is one of the most frequent tumor types worldwide and represents a leading cause of cancer-related deaths. The signali…
Evaluation of the Role of Candida albicans Agglutinin-Like Sequence (Als) Proteins in Human Oral Epithelial Cell Interactions
2012
The fungus C. albicans uses adhesins to interact with human epithelial surfaces in the processes of colonization and pathogenesis. The C. albicans ALS (agglutinin-like sequence) gene family encodes eight large cell-surface glycoproteins (Als1-Als7 and Als9) that have adhesive function. This study utilized C. albicans Δals mutant strains to investigate the role of the Als family in oral epithelial cell adhesion and damage, cytokine induction and activation of a MAPK-based (MKP1/c-Fos) signaling pathway that discriminates between yeast and hyphae. Of the eight Δals mutants tested, only the Δals3 strain showed significant reductions in oral epithelial cell adhesion and damage, and cytokine pro…