Search results for "Chemotaxi"

Generation and release of eosinophil chemotactic factor from human polymorphonuclear neutrophils by arachidonic acid

1978

This study describes the generation and release of an eosinophil chemotactic factor from human polymorphonuclear neutrophils, rat basophilic leukemia cells, and from a lymphocyte monocyte basophil suspension by arachidonic acid (AA). The eosinophil chemotactic factor (ECF) is highly specific for eosinophils and resembles the ECF activity obtained from human polymorpho-nuclear neutrophils after stimulation with the Ca ionophore or during phagocytosis. In this regard, AA-induced ECF represents a biological activity distinct from oxidized AA and its conversion products. AA may therefore have a dual function: it represents an important mechanism of cell activation; as AA is converted into prost…

Prognostic significance of the chemokine CXCL13 in node-negative breast cancer

2013

615 Background: The chemokine CXCL13 is chemotactic for B cells. We examined the prognostic significance of CXCL13 mRNA expression in node-negative breast cancer. Methods: Microarray based gene-expression data for CXCL13 (205242_at) were analysed in four previously published cohorts (Mainz, Rotterdam, Transbig, Yu) of node-negative breast cancer patients not treated with adjuvant therapy (n=824). A meta-analysis of previously published cohorts was performed using a random effects model. Prognostic significance of CXCL13 on metastasis-free survival (MFS) was examined in the whole cohort and in different molecular subtypes (ER+/HER2-, ER-/HER2-, HER2+). Independent prognostic relevance was a…

Endothelial capillaries chemotactically attract tumour cells.

2001

Directional migration of capillaries towards tumour implants is generally assumed to be regulated by chemotaxis. Preliminary evidence has also been presented for the existence of a reverse chemotactic signalling pathway, with capillaries attracting tumour cells via paracrine factors. By using a variety of endothelial cell types and tumour cell lines, this study has systematically investigated chemotaxis between endothelial cells and tumour cells in two- and three-dimensional systems. Checkerboard analysis revealed faint attraction of human umbilical vein endothelial cells (HUVECs), but not porcine aortic endothelial cells (PAECs), by tumour cells. In reverse, both PAECs and HUVECs potently …

Microvascular in vivo assessment of reperfusion injury: significance of prostaglandin E1 and I2 in postischemic “no-reflow” and “reflow-paradox”

2004

Microvascular ischemia-reperfusion (I/R) injury is characterized by failure of capillary perfusion ("no-reflow") and reoxygenation-associated phenomena ("reflow-paradox"), including activation of leukocyte-endothelium interaction with cytotoxic mediator-induced loss of endothelial integrity. The objectives of this study were to elucidate the impact of both prostaglandins E(1) (PGE(1)) and I(2) (PGI(2)) in microvascular reperfusion injury, with special focus on the distinct pathophysiology of no-reflow- and reflow-paradox phenomena.By use of the hamster dorsal skinfold preparation and in vivo fluorescence microscopy, the microcirculation of a striated skin muscle was assessed before 4 h of p…

A potential role of interferon-gamma in the pathogenesis of venous leg ulcers.

2005

Venous leg ulcer is the most severe expression of chronic venous insufficiency. Venous ulcerations are always associated with venous ambulatory hypertension, but the exact mechanism leading from pathological hemodynamics in venous circulation to the necrotic lesions in the skin still remains undiscovered. It has been shown that tissue injury in venous ulcer patients was induced by leukocytes. However, though infiltrating leukocytes have at their disposal a powerfully cytotoxic arsenal, it has not been discovered which molecular mechanisms may contribute to the skin damage. The search for this hypothetical factor responsible for the development of ulceration should be focused on mechanisms l…

The “mode” of lymphocyte extravasation through HEV of Peyer's patches and its role in normal homing and inflammation

2007

The mode of lymphocyte transendothelial migration in the postcapillary high endothelial venules (HEVs) of Peyer's patches during normal homing and acute inflammation in the guinea pig was studied. It is common opinion that the lymphocyte transendothelial passage from the blood stream into the extravasal lymphoid tissue calls for a multistep process of endothelial and lymphocyte molecules favoring tethering, rolling, activation, arrest and its firm adhesion to the endothelial luminal surface. Ultrastructural serial pictures and the three-dimensional reconstruction of HEVs with lymphocytes during different moments of their transmigration through the endothelial wall enabled us to demonstrate …

Pattern formation and bifurcation analysis for some chemotaxis-reaction-diffusion systems

Ganodermycin, a novel inhibitor of CXCL10 expression from Ganoderma applanatum

2011

CXCL10 (inducible protein-10) is a highly inducible chemoattractant, which contributes to the recruitment of inflammatory cells, such as macrophages and T-lymphocytes, and thereby has important roles in chronic inflammatory conditions. In a search for new inhibitors of CXCL10 expression in MonoMac6 cells, a novel compound, designated as Ganodermycin, was isolated from fermentations of the basidiomycete Ganoderma applanatum. The structure was determined by a combination of spectroscopic techniques. Ganodermycin inhibited the lipopolysaccharide (LPS)/interferon (IFN)-γ-induced CXCL10 promoter activity in transiently transfected MonoMac6 cells in a dose-dependent manner with IC(50) values of 1…

Axisymmetric solutions for a chemotaxis model of Multiple Sclerosis

2018

In this paper we study radially symmetric solutions for our recently proposed reaction–diffusion–chemotaxis model of Multiple Sclerosis. Through a weakly nonlinear expansion we classify the bifurcation at the onset and derive the amplitude equations ruling the formation of concentric demyelinating patterns which reproduce the concentric layers observed in Balò sclerosis and in the early phase of Multiple Sclerosis. We present numerical simulations which illustrate and fit the analytical results.

Dynamic deformation of migratory efferent lymph-derived cells ?trapped? in the inflammatory microcirculation

2002

The cellular immune response depends on the delivery of lymphocytes from the lymph node to the peripheral site of antigenic challenge. During their passage through the inflammatory microcirculaton, the migratory cells can become transiently immobilized or "trapped" in small caliber vessels. In this report, we used intravital microscopy and temporal area mapping to define the dynamic deformation of efferent lymph-derived mononuclear cells trapped in the systemic inflammatory microcirculation. Mononuclear cells obtained from the efferent lymph draining the oxazolone-stimulated microcirculation were labeled with fluorescent dye and reinjected into the feeding arterial circulation. Intravital v…