Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Granulocytes play a significant role in vascular diseases. The mechanisms of neutrophil-mediated vascular injury include their increased endothelial adhesion and activation with release of inflammatory mediators. Pentoxifylline (PTX) has a well-demonstrated ability to act on the activated neutrophils. It increases chemotaxis and decreases their adherence to endothelial cells, oxidative burst, and enzyme release. In this preliminary study, we investigated the effects of PTX on ischemia-induced changes in polymorphonuclear neutrophils (PMN) activation and cytokine release. A double-blind, randomized, placebo-controlled trial was carried out in 14 patients (age range 46-86 years) suffering from critical ischemia, as defined by the European Consensus Document, or subacute ischemia due to occlusive arterial disease of the lower limb. Femoral and antecubital venous blood samples on the side of the ischemic leg were obtained from patients immediately before (TO) and after infusion (T24) of PTX or placebo. PMN activation was evaluated by study of cell migration, beta 2 integrin expression (CD11b/ CD18), oxidative burst, and elastase release. Inflammation proteins were analyzed, such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), interleukin-6 (IL-6), C-reactive protein (CRP), and fibrinogen. Before treatment, our results demonstrate an important activation in both femoral and antecubital venous blood. PMN activation markers, cytokine release, and other inflammation proteins were significantly increased compared with normal subjects. In the experimental group there was no significant difference between femoral and antecubital venous blood. Six patients received PTX infusion and seven patients were in the placebo group. The effect of PTX was evaluated after 24 h of treatment (1,200 mg). In the PTX group the following variables were improved compared with the placebo group: CD11b expression on PMNs, elastase released from PMNs, fibrinogen, CRP, TNF-alpha, and IL6 in plasma. These preliminary results should be interpreted with caution because of the small sample size. Further trials may contribute to more complete understanding.
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PMID:Leukocyte activation study during occlusive arterial disease of the lower limb: effect of pentoxifylline infusion. 869 73

The aim of this study was to characterize the changes in the quantitative expression of beta 2-integrins and L-selectin detected by means of fluorochrome-conjugated monoclonal antibodies and flow cytometry on leukocytes in the systemic circulation after a major musculoskeletal trauma, i.e. hip replacement surgery, and to relate these changes to parameters of the acute-phase response [plasma acute-phase reactants (C-reactive protein, CRP, and interleukin-6, IL-6) and parameters of coagulation activation (thrombin-antithrombin III complexes, TAT)]. Eight patients with either primary or secondary osteoarthritis of the hip received uncemented total hip prostheses. LFA-1 (CD11a/CD18) was upregulated on granulocytes during the operation. MAC-1 (CD11b/CD18) expression on monocytes increased to peak levels 20 h after surgery, whereas the L-selectin (CD62L) expression on monocytes and granulocytes reached peak values at the end of surgery. The changes in expression of LFA-1 on monocytes, MAC-1 on granulocytes and p150,95 (CD11c/CD18) on monocytes and granulocytes during and after the operation did not reach statistical significance. TAT and IL-6 increased during surgery and reached peak values at the end of the operation and 20 h after surgery, respectively. In contrast, CPR concentrations increased after surgery with peak levels 44 h postoperatively. Significant upregulation of LFA-1 on granulocytes and L-selectin on monocytes and granulocytes preceded the increase in IL-6 which again preceded the increase in CRP. However, the up- or downregulation of leukocyte beta 2-integrins and L-selectin during and after surgery was not significantly correlated with the increase in IL-6. The increases in TAT correlated well with the upregulation of L-selectin on monocytes, but not with the beta 2-integrins known to participate in the coagulation process in vitro. The rise in CRP was inversely correlated with the maximal increase in expression of MAC-1 on monocytes. In conclusion, the changes in leukocyte adhesion molecules during and after surgery indicate changes in critical leukocyte functions. The lack of correlation between quantitative up- and downregulation of leukocyte beta 2-integrins and parameters of the acute phase response suggests that these processes are regulated through independent pathways or that functional up- and downregulation of adhesion molecules, shedding, leukocyte-endothelial adhesion and mobilization of new unactivated cells may result in a net estimate of leukocyte activation not suspected to be positively correlated to acute-phase reactants.
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PMID:Expression of beta-2-integrins and L-selectin by leukocytes and changes in acute-phase reactants in total hip replacement surgery. 873 29

Although the pathogenesis of the acute respiratory distress syndrome (ARDS) is complex and poorly understood, several observations point to an important role of interactions between polymorphonuclear neutrophils (PMN) and cytokines in this process. We therefore studied certain parameters involved in PMN transendothelial migration (adhesion molecule expression and cytoskeletal organization) in patients with ARDS (n = 14) in comparison with other ventilated patients (n = 15). We found that in the basal state, both whole-blood PMN and alveolar PMN obtained by bronchoalveolar lavage (BAL) were activated, as shown by decreased L-selectin CD62L and increased beta 2 integrin CD11b expression, as well as decreased F-actin content. The degree of PMN activation increased with the degree of lung injury and with the levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-8 (IL-8). Moreover, the capacity of ex vivo stimulation of alveolar PMN by a bacterial peptide was low in ARDS and could partly account for the high susceptibility of these patients to lung infection. Therefore, ARDS-associated lung injury could be caused, at least in part, by inappropriate adhesion and transendothelial migration of proinflammatory cytokine-primed PMN.
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PMID:Interactions between neutrophils and cytokines in blood and alveolar spaces during ARDS. 881 May 92

Six macrophage cell lines, each derived from a bone marrow macrophage colony grown in soft agar, were established by expansion of the macrophage clones in liquid culture until spontaneous transformation occurred. Four lines originated from the LPS(d) nonresponder mouse strain C3H/HeJ and two from the LPS(n) responder strain CBA/J. The cell lines adhered to plastic and glass surfaces and displayed typical macrophage functions such as phagocytosis and nonspecific esterase activity. Flow cytometry analyses showed that the lines expressed the macrophage surface markers CD11b, CD13, CD32/16, F4/80, and BM8 constitutively. A moderate expression of the adhesion receptor CD11a, but only a very low expression of its ligand CD54, was observed. A minor fraction of the cells in each line constitutively expressed MHC class II antigen, and its expression could be up-regulated in each cell line by treatment with interferon-gamma (IFN-gamma). Secretion of the inflammatory mediators nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) after induction by three bacterial derivatives, heat-killed Salmonella typhimurium (HKS), lipopolysaccharide (LPS), and the Mycoplasma fermentans-derived amphiphilic lipid MDHM, were examined in detail. Not only did the lines differ in the amounts of mediators secreted in response to any one stimulus, but the doses of MDHM or LPS required for 50% maximal induction of NO varied up to 10-fold among the four LPS(d) cell lines, suggesting considerable functional heterogeneity between the clones. Secretion of large amounts of TNF-alpha was induced in all the cell lines by HKS. Although it could be shown that exogenously added TNF-alpha acted synergistically with IFN-gamma to induce NO release from the cell lines, an autocrine role for TNF-alpha during HKS-IFN-gamma induction of NO synthesis could not be substantiated. Neutralization of TNF-alpha with a specific antibody completely blocked NO induction by exogenous TNF-alpha but did not abrogate NO release either by HKS-IFN-gamma-induced cells or by macrophages treated with supernatant from an HKS-IFN-gamma-activated cell line. These results indicate that the clones are arrested in distinct stages of differentiation and retain some properties of normal untransformed macrophages. They should be helpful tools for investigations into macrophage function.
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PMID:Characterization of clonally derived, spontaneously transformed bone marrow macrophage cell lines from lipopolysaccharide hyporesponsive LPS(d) and normal LPS(n) mice. 910 34

In this double-blind, cross-over, placebo-controlled, randomized study, two groups of eight healthy male volunteers were challenged with endotoxin (4 ng/kg) on two occasions, once in conjunction with placebo and once with granulocyte colony-stimulating factor (G-CSF; 5 microg/kg). In group 1, G-CSF was administered intravenously 2 hours before endotoxin challenge; in group 2, G-CSF was administered subcutaneously 24 hours before endotoxin challenge. In group 1, G-CSF significantly enhanced the release of tumor necrosis factor (TNF), interleukin-6 (IL-6), IL-8, IL-1 receptor antagonist (IL-1ra), and soluble TNF receptors. In group 2, G-CSF significantly reduced IL-8 concentrations and modestly attenuated TNF and IL-6 levels. In this group, IL-1ra and soluble TNF receptors were enhanced by G-CSF pretreatment and lipopolysaccharide (LPS)-induced soluble TNF receptor release was further augmented, whereas LPS-induced IL-1ra concentrations remained unaltered. Both pretreatments with G-CSF increased LPS-induced peripheral neutrophilia; the expression of CD11b, CD18, and CD67; and the release of elastase and lactoferrin. Both pretreatments also down-regulated neutrophil L-selectin expression and prevented the endotoxin-induced pulmonary neutrophil accumulation during the first 2 hours after endotoxin challenge. These data indicate that two different pretreatments with G-CSF result in differential effects on LPS-induced cytokine release but similar effects on LPS-induced neutrophil activation and changes in expression of cell surface molecules. Finally, regardless of the effects of G-CSF on LPS-induced cytokine release, G-CSF blocks LPS-induced pulmonary granulocyte accumulation.
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PMID:Modulation of cytokine release and neutrophil function by granulocyte colony-stimulating factor during endotoxemia in humans. 926 59

CD23 is expressed on a variety of hemopoietic cells. Recently, we have reported that blocking CD23 interactions in a murine model of arthritis resulted in a marked improvement of disease severity. Here, we demonstrate that CD11b, the alpha chain of the beta 2 integrin adhesion molecule complex CD11b/CD18 expressed on monocytes interacts with CD23. Using a recombinant fusion protein (ZZ-CD23), murine CD23 was shown to bind to peritoneal macrophages and peripheral blood cells isolated from mice as well as the murine macrophage cell line, RAW. The interactions between mouse ZZ-CD23 and CD11b/CD18-expressing cells were significantly inhibited by anti-CD11b monoclonal antibodies. A functional consequence was then demonstrated by inducing an up-regulation of interleukin-6 (IL-6) production following ZZ-CD23 incubation with monocytes. The addition of Fab fragments generated from the monoclonal antibody CD11b impaired this cytokine production by 50%. Interestingly, a positive autocrine loop was identified as IL-6 was shown to increase CD23 binding to macrophages. These results demonstrate that similar to findings using human cells, murine CD23 binds to the surface adhesion molecule, CD11b, and these interactions regulate biological activities of murine myeloid cells.
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PMID:Mouse CD23 regulates monocyte activation through an interaction with the adhesion molecule CD11b/CD18. 934 71

A whole-blood model was used to evaluate the effects of temperature and anticoagulant on the expression of activation markers HLA-DR and CD11b on peripheral leukocytes. Venous blood, anticoagulated with either EDTA or heparin, was obtained from six healthy blood donors and 13 hospitalized patients (8 human immunodeficiency virus type 1-seropositive individuals with concurrent pulmonary tuberculosis and 5 patients with pneumonia). A preliminary evaluation was carried out with whole blood from two of the normal donors, and cells were stained immediately for HLA-DR and CD11b markers or stained after incubation at room temperature or 37 degreesC for 18 h with or without the addition of the cytokines gamma interferon (IFN-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF), IFN-gamma plus GM-CSF, tumor necrosis factor beta, or interleukin-6. Of the cytokines tested, the combination of IFN-gamma and GM-CSF had the most pronounced modulation of marker expression on polymorphonuclear neutrophils (PMN), in particular, HLA-DR expression, which required induction for its detection. These cytokines were therefore used in further evaluations that considered the above-mentioned effects in the presence of disease. Results indicated that the expression of activation markers on PMN and lymphocytes in whole blood are influenced by the temperature of incubation and the choice of anticoagulant and the effects noted were dependent on (i) the particular cell surface marker, (ii) the cell type being studied, and (iii) the presence or absence of disease. It is therefore recommended that ex vivo whole-blood models for evaluating phenotype or immune function be carefully evaluated for the above-mentioned effects.
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PMID:Effects of anticoagulants and temperature on expression of activation markers CD11b and HLA-DR on human leukocytes. 972 38

Monocytes/macrophages (Mo) appear to play a critical role in the initiation and progression of atherosclerotic lesions. In this study, we characterized in vitro-differentiated embryonic stem (ES) cell macrophages as a model system for studying atherosclerosis-associated Mo functions. Using immunofluorescence staining and Western analysis, we demonstrate that ES Mo express typical macrophage cell surface markers, as well as the known receptors for modified forms of low density lipoprotein (LDL), including the Mo scavenger receptors (SR-A type I and type II), CD36, and CD68. Differentiated ES Mo specifically bind and degrade 125I-labeled acetylated LDL with high affinity, and their incubation with acetylated LDL (15 microg/mL) for 48 hours produces characteristic "foamy" Mo, as visualized by oil red O staining. ES Mo also express matrix-degrading metalloproteinases (MMP-3, MMP-9), which have been implicated in collagen breakdown in the fibrous cap of atherosclerotic plaques, and secrete cytokines (tumor necrosis factor-alpha, interleukin-6) in response to inflammatory stimuli. Transfection experiments, using a green fluorescent protein reporter gene, driven by the myeloid-specific promoter, CD11b, demonstrated that ES Mo can also be used to study macrophage-restricted gene expression in vitro. Taken together, these data demonstrate that ES Mo exhibit many properties typical of arterial lesion macrophages. Its ease of genetic manipulation makes it an attractive system for investigations of macrophage functions in vitro.
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PMID:In vitro-differentiated embryonic stem cell macrophages: a model system for studying atherosclerosis-associated macrophage functions. 976 39

Criteria of the systemic inflammatory response syndrome (SIRS) are known to include patients without systemic inflammation. Our aim was to explore additional markers of inflammation that would distinguish SIRS patients with systemic inflammation from patients without inflammation. The study included 100 acutely ill patients with SIRS. Peripheral blood neutrophil and monocyte CD11b expression, serum interleukin-6, interleukin-1beta, tumour necrosis factor-alpha and C-reactive protein were determined, and severity of inflammation was evaluated by systemic inflammation composite score based on CD11b expression, C-reactive protein and cytokine levels. Levels of CD11b expression, C-reactive protein and interleukin-6 were higher in sepsis patients than in SIRS patients who met two criteria (SIRS2 group) or three criteria of SIRS (SIRS3 group). The systemic inflammation composite score of SIRS2 patients (median 1.5; range 0-8, n=56) was lower than that of SIRS3 patients (3.5; range 0-9, n=14, P=0.013) and that of sepsis patients (5.0; range 3-10, n=19, P<0.001). The systemic inflammation composite score was 0 in 13/94 patients. In 81 patients in whom systemic inflammation composite scores exceeded 1, interleukin-6 was increased in 64 (79.0%), C-reactive protein in 59 (72.8%) and CD11b in 50 (61.7%). None of these markers, when used alone, identified all patients but at least one marker was positive in each patient. Quantifying phagocyte CD11b expression and serum interleukin-6 and C-reactive protein concurrently provides a means to discriminate SIRS patients with systemic inflammation from patients without systemic inflammation.
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PMID:Systemic inflammatory response syndrome without systemic inflammation in acutely ill patients admitted to hospital in a medical emergency. 1002 65

Fibrin derived from fibrinogen after thrombin cleavage plays an essential role in forming blood clots. Fibrin as well as fibrinogen is also involved in the induction of platelet aggregation, leukocyte cell adhesion and phagocytosis. An additional biological role of fibrin and fibrinogen is presented in this study. One of the proteolytic peptides of fibrin/fibrinogen, fragment E, and not fragment D, was able to stimulate rat peritoneal macrophages to express interleukin-6 (IL-6). The stimulation of fibrin/fibrinogen fragment E on macrophages appeared to work in a dose- and time-dependent manner. Adherent fibrin fragment E was able to stimulate IL-6 expression as well as IL-6 protein production. The effect of fibrin fragment E was inhibited by the addition of an excess amount of GPRP tetrapeptide, but not by GHRP, which are the amino acids derived from the amino terminus of fibrin alpha and beta chains, respectively. These results suggest that fibrin as well as fibrinogen function as a stimulator to macrophages, and leukocyte integrin p150,95 (CD11c/ CD18), not Mac-I (CD11b/CD18), is involved in mediating fibrin stimulatory activity in macrophages.
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PMID:Fragment E derived from both fibrin and fibrinogen stimulates interleukin-6 production in rat peritoneal macrophages. 1010 64


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