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Results 551 - 600 of 1084
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Dizer Ufuk - - 2005
BACKGROUND: Brucellosis is one of the important health problems for both humans and animals in Turkey since agriculture and stock raising appears to be the most important means of subsistence. Investigations on the pathogenesis of brucellosis reveal that the etiologic agent can survive in phagocytic cells, and cell-mediated immunity plays ...
Hose Stacey - - 2005
Several studies have shown that macrophages play an active role in the initiation and completion of the programmed cell death process during development. Macrophages are called professional phagocytes, as their primary role is phagocytosis. The process of phagocytosis is complex and to date only poorly defined. It has also been ...
Grau Georges E - - 2005
Programmed cell death plays a crucial role in the maintenance of cell homeostasis. An initial, effector phase leads to the generation of apoptotic corpses and is closely followed by a swift clearance by professional or amateur phagocytes. Several aspects distinguish this latter process of engulfment of dying cells from the ...
Skoberne M - - 2005
Clearance of apoptotic cells by phagocytes can result in either anti-inflammatory and immunosuppressive effects or prostimulatory consequences through presentation of cell-associated antigens to T cells. The differences in outcome are due to the conditions under which apoptosis is induced, the type of phagocytic cell, the nature of the receptors involved ...
Simitsopoulou Maria - - 2005
Candida albicans and non-albicans Candida spp. can cause serious infections in hospitalized and immunocompromised patients. A large number of antifungal agents and immunomodulators have been developed and may interact with both polymorphonuclear and mononuclear phagocytes against blastoconidia and pseudohyphae of Candida spp. Blastoconidia are predominantly destroyed by phagocytosis, whereas pseudohyphal ...
Devitt Andrew - - 2004
Interaction of macrophages with apoptotic cells involves multiple steps including recognition, tethering, phagocytosis, and anti-inflammatory macrophage responses. Defective apoptotic cell clearance is associated with pathogenesis of autoimmune disease. CD14 is a surface receptor that functions in vitro in the removal of apoptotic cells by human and murine macrophages, but its ...
Huang Yuh-Chin T - - 2004
Pollutant particles induce apoptosis and inflammation, but the relationship between these two biological processes is not entirely clear. In this study, we compared the proapoptotic and proinflammatory effects of four particles: residual oil fly ash (ROFA), St. Louis particles SRM 1648 (SL), Chapel Hill PM10 (CHP), and Mount St. Helens ...
Germain Ronald N - - 2004
"Nature has provided, in the white corpuscles as you call them-in the phagocytes as we call them-a natural means of devouring and destroying all disease germs. There is at bottom only one genuinely scientific treatment for all diseases, and that is to stimulate the phagocytes." So opined B.B. in G.B. ...
Sun E - - 2004
Cell death through apoptosis plays a critical role in regulating cellular homeostasis. Whether the disposal of apoptotic cells through phagocytosis can actively induce immune tolerance in vivo, however, remains controversial. Here, we report in a rat model that without using immunosuppressants, transfusion of apoptotic splenocytes from the donor strain prior ...
Lombaert Noömi - - 2004
The present study aimed at comparing in vitro the apoptogenic properties of metallic cobalt (Co), tungsten carbide (WC) and tungsten carbide-cobalt (WC-Co) in conditions known to cause genotoxicity. Human peripheral blood mononucleated cells were incubated with 2.0-6.0 microg/ml of Co alone or mixed with WC particles and 33.3-100.0 microg/ml WC ...
Yamauchi Akira - - 2004
The Rho family GTPase Rac is a crucial participant in numerous cellular functions and acts as a molecular switch for signal transduction. Mice deficient in hemopoietic-specific Rac2 exhibited agonist-specific defects in neutrophil functions including chemoattractant-stimulated filamentous actin polymerization and chemotaxis, and superoxide production elicited by phorbol ester, fMLP, or IgG-coated ...
Balduzzi M - - 2004
The RAW 246.7 macrophage cell line was exposed in vitro to aged crystalline silica particles of respirable size for 24 h at a range of doses starting from 15 microg/2 x 10(6) cells, which is a realistic exposure level of macrophages in the airways of ambiently exposed individuals. The particle ...
Gregory Christopher D - - 2004
Macrophages play important roles in the clearance of dying and dead cells. Typically, and perhaps simplistically, they are viewed as the professional phagocytes of apoptotic cells. Clearance by macrophages of cells undergoing apoptosis is a non-phlogistic phenomenon which is often associated with actively anti-inflammatory phagocyte responses. By contrast, macrophage responses ...
Gold Elizabeth S - - 2004
Macrophages play a critical role in both innate and acquired immunity because of their unique ability to internalize, kill, and degrade bacterial pathogens through the process of phagocytosis. The adaptor protein, amphiphysin IIm, participates in phagocytosis and is transiently associated with early phagosomes. Certain pathogens, including Chlamydia pneumoniae, have evolved ...
Iyer Shankar S - - 2004
Phagocytosis is a fundamental feature of the innate immune system, required for antimicrobial defense, resolution of inflammation, and tissue remodeling. Furthermore, phagocytosis is coupled to a diverse range of cytotoxic effector mechanisms, including the respiratory burst, secretion of inflammatory mediators and Ag presentation. Phospholipase D (PLD) has been linked to ...
Veranth John M JM Department of Pharmacology and Toxicology, 112 Skaggs Hall, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112-5820, USA. - - 2004
Cultured human lung epithelial cells (BEAS-2B) were treated in vitro with PM(2.5)-enriched particles of soil-derived mineral dust from nine sites in the western United States. The particle samples simulate windblown dust and vehicle-generated emissions from unpaved roads. Five of the sites yielded relatively benign dust. Particles from three sites caused ...
Cunha Elisabete M - - 2004
Phagocytes remove and store mercury (Hg) that enters the body. Macrophages and granulocytes respond in opposite ways to Hg: macrophages loose cell viability, and neutrophils become protected from apoptosis. We have investigated the cytology of early intake of Hg by macrophages and neutrophils after a short period (2-4 min) of ...
Yagil-Kelmer Efrat - - 2004
It is well recognized that wear particles derived from orthopaedic implants have the potential to induce inflammation, which may eventually lead to aseptic loosening of the artificial joint. We hypothesized that alumina ceramic particles of different sizes cause a differential cytokine response by human monocytes. To test this hypothesis a ...
Yona Simon - - 2004
The role of the glucocorticoid-regulated protein annexin 1 during the process of phagocytosis has been studied using annexin 1 null peritoneal macrophages. Wild type and annexin 1 null macrophages were incubated with several distinct phagocytic targets. No differences were observed in rate or the maximal response with respect to IgG ...
Kirkham Paul A - - 2004
Clearance of apoptotic cells by phagocytosis plays an important role in the resolution of an inflammatory response. Macrophages interacting with extracellular matrix (ECM) proteins upregulate their phagocytic capacity. Cigarette smoke contains highly reactive carbonyls that modify proteins which directly/indirectly affects cellular function. We observed, in vitro, that human macrophages interacting ...
Hanayama Rikinari - - 2004
Apoptotic cells expose phosphatidylserine and are swiftly engulfed by macrophages. Milk fat globule epidermal growth factor (EGF) factor 8 (MFG-E8) is a protein that binds to apoptotic cells by recognizing phosphatidylserine and that enhances the engulfment of apoptotic cells by macrophages. We report that tingible body macrophages in the germinal ...
Knaapen Ad M - - 2004
Both occupational and environmental exposure to particles is associated with an increased risk of lung cancer. Particles are thought to impact on genotoxicity as well as on cell proliferation via their ability to generate oxidants such as reactive oxygen species (ROS) and reactive nitrogen species (RNS). For mechanistic purposes, one ...
Chow Chung-Wai - - 2004
Phagocytosis is an essential component of the innate immune response. Invading microorganisms are engulfed by neutrophils and macrophages, and subsequently killed by a complex series of reactions that require fusion of the phagocytic vacuole with multiple endomembrane organelles. This vacuolar remodeling process, known as phagosomal maturation, is often the target ...
Savill, John
During embryonic development, the sculpting of many tissues depends on waves of apoptotic cell death among different cell populations. Unfortunately, at least in higher animals with sophisticated immune systems, dying cells must be engulfed by phagocytes to prevent a massive autoimmune response. In their Perspective, Savill et al. discuss new ...
Ruthel Gordon - - 2004
Macrophages attempt to battle infection with Bacillus anthracis spores by phagocytosis of the spores. However, it is believed that B. anthracis spores may survive phagocytosis and may actually use the macrophages that ingest them as a means of transport to lymph nodes. Thus far, the events that occur after spores ...
Hanayama Rikinari - - 2004
A major function of macrophages is to engulf apoptotic cells to prevent them from releasing noxious materials as they die. Milk fat globule-EGF-factor 8 (MFG-E8) is a glycoprotein secreted by activated macrophages that works as a bridge between apoptotic cells and phagocytes by specifically recognizing phosphatidylserine exposed on apoptotic cells. ...
Fujishiro Takaaki - - 2004
Early implant instability has been proposed as a critical factor in the onset and progression of aseptic loosening and periprosthetic osteolysis in total joint arthroplasties. Previous in vitro studies have reported that macrophages stimulated with cyclic mechanical strain release inflammatory mediators. Little is known, however, about the response of these ...
Hamilton Raymond F RF - - 2004
The mechanism for how inhaled particles cause or exacerbate human diseases is not known. It is clear, however, that some particles are more bioactive than others. One possible mechanism may involve a modification of antigen-presenting cell function. In this study, 2 forms of asbestos (crocidolite and Libby amphibole) and PM(2.5) ...
Licht R - - 2004
Antibodies against nucleosomes are a serological hallmark of systemic lupus erythematosus (SLE). Apoptotic cells are the unique source of nucleosomes, which are formed through cleavage of chromatin by nucleases. These nucleosomes and other autoantigens targeted in SLE are expressed in apoptotic blebs or at the surface of apoptotic cells. Therefore, ...
Groos Stephanie - - 2004
The success or failure of the clearance of apoptotic cell remains depends on the ability of phagocytic cells to recognize, phagocytoze, and digest these remains prior to their lysis, which would cause tissue inflammation. We have recently shown that, after mass-induced apoptosis of guinea pig colonocytes in vivo, phagocytosis by ...
Takahashi Munehisa - - 2004
We have demonstrated that phagocytosis of late apoptotic cells by mouse macrophages leads to the production of proinflammatory cytokines, notably macrophage-inflammatory protein (MIP-2), and therefore, a yet-unknown mechanism(s) should keep our body free of inflammation. In this study, we examined the effect of the addition of immature dendritic cells (iDCs) ...
Patel Samir N - - 2004
Phagocytic cells represent an important line of innate defense against malaria; however, little is known of the mechanism by which macrophages recognize Plasmodium falciparum-parasitized erythrocytes (PEs). Using macrophages from CD36 wild-type (WT), CD36-null, and CD36 transgenically-rescued rodents, we demonstrate a major role for CD36 in the phagocytosis of PEs. WT ...
Brown D M - - 2004
The effects of PM10, one of the components of particulate air pollution, was investigated using human monocytes and a mouse macrophage cell line (J774). The study aimed to investigate the role of these nanoparticles on the release of the pro-inflammatory cytokine TNF-alpha and IL-1alpha gene expression. We also investigated the ...
Santini Maria Teresa - - 2004
Because of the association between inhalation of airborne particulate matter (PM) and human respiratory and cardiovascular disease, it is necessary to understand the tissue damage induced by these particles. One of the cell types principally involved in the body's reaction to PM are macrophages, which remove particles in the airway ...
Sexton Kenneth G - - 2004
Complex urban air mixtures that realistically mimic urban smog can be generated for investigating adverse health effects. "Smog chambers" have been used for over 30 yr to conduct experiments for developing and testing photochemical models that predict ambient ozone (O(3)) concentrations and aerosol chemistry. These chambers were used to generate ...
Böse Jens - - 2004
BACKGROUND: Phagocytosis of apoptotic cells is fundamental to animal development, immune function and cellular homeostasis. The phosphatidylserine receptor (Ptdsr) on phagocytes has been implicated in the recognition and engulfment of apoptotic cells and in anti-inflammatory signaling. To determine the biological function of the phosphatidylserine receptor in vivo, we inactivated the ...
Rosen Henry - - 2004
PURPOSE OF REVIEW: This review focuses on adaptive bacterial interactions with neutrophils, emphasizing information communicated within the past year about bacterial factors that respond to contact with or phagocytosis by PMN. RECENT FINDINGS: Since the discovery of type III and IV secretion, progress in the analysis of bacterial interactions with ...
M.A. Qureshi
A study was conducted to measure baseline immunocompetence of Arbor Acre broiler chicks after the birds were raised on hyperimmune bovine colostrum product ‘Immunmilk<sup>®</sup>` for first 7 d of age. Immunological parameters measured were <i>in vivo</i> and <i>in vitro</i> lymphoproliferation, macrophage functions which included phagocytosis, nitric oxide production and <i>E. ...
Maderna Paola - - 2003
Clearance of apoptotic cells by phagocytic cells plays a significant role in the resolution of inflammation, protecting tissue from harmful exposure to the inflammatory and immunogenic contents of dying cells. Apoptosis induces cell surface changes that are important for recognition and engulfment of cells by phagocytes. These changes include alterations ...
Tyurina Yulia Y - - 2004
Apoptosis is associated with the externalization of phosphatidylserine (PS) in the plasma membrane and subsequent recognition of PS by specific macrophage receptors. Selective oxidation of PS precedes its externalization/recognition and is essential for the PS-dependent engulfment of apoptotic cells. Because etoposide is a potent and selective lipid antioxidant that does ...
Rosenberg Carolina E - - 2003
Lead is an element of risk for the environment and human health and has harmful effects that may exceed those of other inorganic toxicants. The immune system is one of the targets of lead. Its immunomodulatory actions depend on the level of exposure, and it has been demonstrated that environmental ...
Kurosaka Kahori - - 2003
Apoptotic cells are phagocytosed as soon as they appear in vivo. In this study, we first determined precisely at what stage apoptotic cells are phagocytosed by macrophages, and then examined the subsequent cytokine production. Phagocytosis was confirmed by flow cytometry and confocal laser microscopy, whereas the subsequent response was examined ...
Saillan-Barreau C - - 2003
Macrophages are part of the immunity defense mechanism via oxidative burst and phagocytosis. They are also involved in tissue remodeling via cytokine secretion and apoptotic body clearance. Previously, we demonstrated that adipose cells and macrophages share some of their features and functions. Our aim was to further test this hypothesis ...
Chan Andrew - - 2003
Apoptosis of autoaggressive T-cells in the CNS is an effective, noninflammatory mechanism for the resolution of T-cell infiltrates, contributing to clinical recovery in T-cell-mediated neuroinflammatory diseases. The clearance of apoptotic leukocytes by tissue-specific phagocytes is critical in the resolution of the inflammatory infiltrate and leads to a profound downregulation of ...
Lalancette A - - 2003
Mercury is the principal metal contaminant in the St Lawrence Estuary. It impairs humoral, cellular and non-specific immune responses in many species. Since the immune system of juvenile seals is immature, it should react differently to the effects of contamination compared to that of mature animals. Phagocytosis and lymphoblastic transformation ...
Jersmann Hubertus P A - - 2003
Inflammatory diseases are associated with reduced serum concentrations of alpha(2)-HS glycoprotein (the human homologue of bovine fetuin), but the role of fetuin in inflammation is poorly understood. We hypothesized that fetuin may influence the resolution of inflammation by modulating the phagocytosis of apoptotic cells by macrophages. Using an in vitro ...
Miyanishi Keita - - 2003
VEGF and VEGF receptor, Flt-1, expression was observed in periprosthetic tissues surrounding loosened total joint implants. Exposure of monocyte/macrophages to titanium particles resulted in increased VEGF expression, p44/42 MAPK activation, and VEGF-dependent macrophage chemotaxis. Increased levels of angiogenic factors, such as VEGF, may be critically important in wear debris-induced implant ...
Sano Hideki - - 2003
Galectin-3 is a member of a large family of animal lectins. This protein is expressed abundantly by macrophages, but its function in this cell type is not well understood. We have studied the effect of galectin-3 gene targeting on phagocytosis, a major function of macrophages. Compared with wild-type macrophages, galectin-3-deficient ...
Desjardins Michel - - 2003
Phagocytosis is the process that cells have evolved to internalise large particles such as mineral debris, which they store, or apoptotic cells and pathogens, which they have the capacity to kill and degrade. However, several important pathogens can suppress these killing functions and survive and multiply within phagosomes, causing disease. ...
Safir Nadia - - 2003
The J774.1 macrophage cell line was used as a tool to investigate the influence of selenium on macrophage function. In vitro selenium supplementation enhanced phagocytosis, degranulation by the release of beta-glucuronidase after N-formyl-methionyl-leucyl-phenylalanine (FMLP) or cytochalasin B, and the production of superoxide anion after phorbol myristate acetate stimulation of these ...
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