Search results for "Selectin"

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.

A methodology to select the price criterion in public procurement

2015

[EN] The construction sector is a key driver for economic growth in any nation and public procurement is one of its pillars hence the importance of the study and investigation of its mechanisms, especially tendering criteria. Price is the main deciding factor for most tenders and projects must have an appropriate base price relative to market price to avoid problems during the execution of the project. Most research on price criteria has been developed from the point of view of bidders and has discussed the development of tools and methodologies for determining the optimal bid price. In this paper we propose a methodology for public procurement procedures from the point of view of the admin…

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

2008

In human endothelial cells rapamycin causes mTORC2 inhibition and impairs cell viability and function.

2008

Aim Drug-eluting stents are widely used to prevent restenosis but are associated with late endothelial damage. To understand the basis for this effect, we have studied the consequences of a prolonged incubation with rapamycin on the viability and functions of endothelial cells. Methods and results Human umbilical vein or aorta endothelial cells were exposed to rapamycin in the absence or in the presence of tumour necrosis factor α (TNFα). After a 24 h-incubation, rapamycin (100 nM) caused a significant cell loss associated with the increase of both apoptosis and necrosis, as quantified by propidium iodide staining, caspase 3 activity, and lactate dehydrogenase release. Rapamycin also impair…

Ionizing radiation-induced E-selectin gene expression and tumor cell adhesion is inhibited by lovastatin and all-trans retinoic acid

2004

E-selectin mediated tumor cell adhesion plays an important role in metastasis. Here we show that ionizing radiation (IR) induces E-selectin gene and protein expression in human endothelial cells at therapeutically relevant dose level. E-selectin expression is accompanied by an increase in the adhesion of human colon carcinoma cells to primary human umbilical vein endothelial cells (HUVEC). The HMG-CoA reductase inhibitor lovastatin impairs IR-stimulated E-selectin expression as analyzed at the level of the protein, mRNA and promoter. Inactivation of Rho GTPases either by use of Clostridium difficile toxin A or by co-expression of dominant-negative Rho blocked IR-induced E-selectin gene indu…

Enzymatically modified, nonoxidized LDL induces selective adhesion and transmigration of monocytes and T-lymphocytes through human endothelial cell m…

1999

Abstract —Circulating monocytes and T lymphocytes extravasate through the endothelium at sites of developing atheromatous lesions, where they tend to accumulate and mediate the progression of the disease. We have previously demonstrated the presence of an enzymatically degraded, nonoxidized form of LDL (E-LDL) in early human fatty streaks, which possesses major biological properties of an atherogenic lipoprotein. The effects of E-LDL on human endothelial cells have now been studied with respect to adhesion and transmigration of monocytes and T lymphocytes. E-LDL induced a rapid and dose-dependent selective adhesion of monocytes and T lymphocytes to endothelial cell monolayers within 30 min…

Analysis of the Biological Response of Endothelial and Fibroblast Cells Cultured on Synthetic Scaffolds with Various Hydrophilic/Hydrophobic Ratios: …

2009

In this study we developed polymer scaffolds intended as anchorage rings for cornea prostheses among other applications, and examined their cell compatibility. In particular, a series of interconnected porous polymer scaffolds with pore sizes from 80 to 110 microns were manufactured varying the ratio of hydrophobic to hydrophilic monomeric units along the polymer chains. Further, the effects of fibronectin precoating, a physiological adhesion molecule, were tested. The interactions between the normal human fibroblast cell line MRC-5 and primary human umbilical vein endothelial cells (HUVECs) with the scaffold surfaces were evaluated. Adhesion and growth of the cells was examined by confocal…

Isolation and molecular characterization of brain microvascular endothelial cells from human brain tumors.

2002

Brain tumor formation and growth is accompanied by the proliferation and infiltration of blood capillaries. The phenotypes of endothelial cells that make up capillaries are known to differ not only in the tissues in which endothelial cells are located but also as a result of the microenvironment to which they are exposed. For this reason, primary cultures of brain endothelial cells were isolated from human brain tumors removed by surgery and compared with cells from normal tissue. The primary confluent monolayers that grew out of isolated capillary fragments consisted of closely associated, elongated, fusiform-shaped cells. But brain tumor-derived endothelial cells in culture exhibited sign…

Increased expression of ICAM-1, E-selectin, and VCAM-1 by cultured human endothelial cells upon exposure to haptens.

1992

Contact allergens induce several accessory signals which promote the activation of antigen-specific T cells. One of these signals is the increased expression of adhesion molecules on antigen-presenting cells and endothelial cells. Epicutaneous application of non-toxic doses of 2,4-dinitrofluorobenzene (DNFB) onto the skin of non-sensitized individuals elicited progressive staining for ICAM-1 on dermal microvascular endothelial cells. To elucidate the question of whether contact allergens can act directly on endothelial cells to elevate their expression of surface structures that bind leukocytes, confluent monolayers of human umbilical vein endothelial cells were incubated with the contact a…

Staphylococcus aureus alpha toxin mediates polymorphonuclear leukocyte-induced vasocontraction and endothelial dysfunction.

2002

The effect of Staphylococcus aureus alpha toxin (alpha-toxin) on selectin-mediated neutrophil adhesion was investigated in polymorphonuclear leukocyte- (PMN) induced vasocontraction and endothelial dysfunction. Adherence of human PMNs to rat aortic endothelium increased significantly following stimulation of the endothelium with alpha-toxin (0.1, 0.5, and 1 microg/mL). This effect could be significantly attenuated by monoclonal antibodies directed against P-selectin or fucoidin, a carbohydrate known to block selectins. Unstimulated human PMNs (10(6)cells/mL) were added to organ chambers containing rat aortic rings stimulated with alpha-toxin (0.5 microg/mL). PMNs elicited a significant vaso…