Search results for "NEUTROPHIL"

Characterization of a Computerized Assay for Rapid and Easy Determination of Leukocyte Adhesion to Endothelial Cells

2005

We report on a facile and rapid computerized in-vitro assay for the quantification of leukocyte adhesion to endothelial cells under static conditions using bovine polymorphonuclear neutrophils (PMN) or human leukaemic Mono Mac 6 cells (MM6) and bovine aorta endothelial cells (BAEC). Images of leukocytes adherent to BAEC monolayers grown in microtiter plates were obtained by a digital camera attached to a conventional microscope and transferred to the public domain NIH ImageJ program for analysis. Using individually adapted program routines adherent leukocytes are easily discriminated and reproducibly quantified. The results obtained with our assay correspond to previous findings and demonst…

Differential adhesion of polymorphous neutrophilic granulocytes to macro- and microvascular endothelial cells under flow conditions.

2002

<i>Objective:</i> As one of the important active barriers in the human organism, endothelial cells (EC) play a central role in the biological reaction to a variety of stimuli, e.g. during the induction and regulation of inflammation, as well as in the reaction to transplantation and biomaterial implantation. In the study of endothelial function, the most widely used in vitro model is that of human umbilical vein EC (HUVEC), i.e. an EC type of embryonic and macrovascular origin. However, many of the important pathological processes occur at microvascular level, thus questioning the validity of the HUVEC model. Moreover, the morphological and functional heterogeneity of the endoth…

Subendothelial infiltration of neutrophil granulocytes and liberation of matrix-destabilizing enzymes in an experimental model of human neo-intima.

2008

SummaryIt was the objective of this study to examine the role of human neutrophil granulocytes (PMN) in an in-vitro model of human neo-intima developed for the study of atherosclerosis. Human granulocytes were subjected to a co-culture model of human endothelial and smooth muscle cells. Subendothelial lipid accumulation was achieved by addition of native LDL to the culture medium. Tissue samples were analyzed by immunohistochemistry and scanning/transmission electron microscopy, and culture supernatants were examined for the presence of interleukin- 8 (IL-8), MCP-1, GRO-α, elastase and matrixmetalloproteinase-8 (MMP-8). Following addition of 2 mg/ml LDL, adherence, transmigration and infilt…

Spatial and temporal heterogeneity of ventilator-associated lung injury after surfactant depletion.

2008

Volutrauma and atelectrauma have been proposed as mechanisms of ventilator-associated lung injury, but few studies have compared their relative importance in mediating lung injury. The objective of our study was to compare the injury produced by stretch (volutrauma) vs. cyclical recruitment (atelectrauma) after surfactant depletion. In saline-lavaged rabbits, we used high tidal volume, low respiratory rate, and low positive end-expiratory pressure to produce stretch injury in nondependent lung regions and cyclical recruitment in dependent lung regions. Tidal changes in shunt fraction were assessed by measuring arterial Po2 oscillations. After ventilating for times ranging from 0 to 6 h, lu…

Mast cell-derived mediators promote murine neutrophil effector functions

2013

Mast cells are able to trigger life-saving immune responses in murine models for acute inflammation. In such settings, several lines of evidence indicate that the rapid and protective recruitment of neutrophils initiated by the release of mast cell-derived pro-inflammatory mediators is a key element of innate immunity. Herein, we investigate the impact of mast cells on critical parameters of neutrophil effector function. In the presence of activated murine bone marrow-derived mast cells, neutrophils freshly isolated from bone marrow rapidly lose expression of CD62L and up-regulate CD11b, the latter being partly driven by mast cell-derived TNF and GM-CSF. Mast cells also strongly enhance neu…

Synthesis and biological properties of the seven alanine-modified analogues of the marine cyclopeptide hymenamide C

2002

The synthesis and biological activity of the marine cyclopeptide hymenamide C(1), showing an inhibitory effect on human neutrophil elastase degranulation release, were recently described. Based on this result, it was decided to undertake a systematic structure-activity relationship study of this cyclopeptide, based on the Ala-scan technique, in order to obtain useful information for the rational design of additional analogues. The synthesis and characterization of the seven Ala modified analogues are reported and their biological and pharmacological properties are described.

Prostaglandin production by human polymorphnuclear leucocytes during phagocytosis in vitro.

1977

Human polymorphonuclear leukocytes were found to be able to synthetize and release substantial amounts of PGE2' when stimulated by a phagocytic stimulus such as zymosan particles coated with complement. Hydrocortisone, at a concentration of 10(-5) M, which proved to be effective in other biological systems, failed to inhibit phagocytosis and PG release.

Interferon-?? Alone versus Interferon-?? plus Ribavirin in Patients with Chronic Hepatitis C Not Responding to Previous Interferon-?? Treatment

2000

Objective: To study the effects of monotherapy with leucocyte interferon-α (IFNα) versus IFNα + ribavirin in patients with chronic hepatitis C who were nonresponders to previous courses of recombinant or lymphoblastoid IFNα. Design and setting: This was a nonblind randomised study of outpatients at 3 centres in Palermo, Sicily, Italy. Patients and participants: We recruited 72 patients (48 males, 24 females), mean age 48.8 ± 6.6 years (range 31 to 63 years), with biopsy-proven chronic hepatitis C, predominantly genotype lb. Interventions: 24 patients (group A) received IFNα 6MU 3 times weekly for 6 months, and 48 patients (group B) received IFNα 6MU 3 times weekly + ribavirin 1200 mg/day fo…

Effects of hydrocortisone on binding of IgG or C3b-coated erythrocytes to human monocytes and polymorphonuclear leucocytes.

1979

Molecular Mechanisms of the Crosstalk Between Mitochondria and NADPH Oxidase Through Reactive Oxygen Species—Studies in White Blood Cells and in Anim…

2014

Aims: Oxidative stress is involved in the development of cardiovascular disease. There is a growing body of evidence for a crosstalk between different enzymatic sources of oxidative stress. With the present study, we sought to determine the underlying crosstalk mechanisms, the role of the mitochondrial permeability transition pore (mPTP), and its link to endothelial dysfunction. Results: NADPH oxidase (Nox) activation (oxidative burst and translocation of cytosolic Nox subunits) was observed in response to mitochondrial reactive oxygen species (mtROS) formation in human leukocytes. In vitro, mtROS-induced Nox activation was prevented by inhibitors of the mPTP, protein kinase C, tyrosine kin…