European cytokine network
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European cytokine network · Sep 2000
Sublethal hemorrhagic shock reduces tumor necrosis factor-alpha-producing capacity in different cell compartments.
Hemorrhagic shock results in a severe impairment of the immune response. Immunological alterations after hemorrhagic shock thus appear to be responsible for reduced resistance to infectious agents commonly observed after shock and severe injury. In the present study we examined the TNF-alpha-producing capacity of immune cells derived from different organs after sublethal shock in rats. ⋯ However, in the serum samples with TNF-alpha-inhibitory activity, elevated levels of PGE2 metabolites were found, which suggests the involvement of prostaglandins in trauma-induced immunosuppression. Altered TNF-a expression might be partially explained by an inhibitory activity in the serum already present 2 hours after shock. Since adequate, but not overwhelming TNF-alpha production is essential for host response, the altered cytokine formation might explain local and systemic susceptibility to infections after hemorrhagic shock.
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European cytokine network · Jun 2000
Transforming growth factor-beta(1), -beta(2), -beta(3), basic fibroblast growth factor and vascular endothelial growth factor expression in keratinocytes of burn scars.
Keratinocytes are increasingly recognized as key regulators of skin inflammation and remodeling, as they are capable of producing growth factors and cytokines that are important mediators in the wound healing process. We investigated the expression and distribution of TGF-beta 1 mRNA by mRNA in situ hybridization and of TGF-beta 1, TGF-beta 2, TGF-beta 3, bFGF and VEGF protein expression using immunohistochemistry in spontaneously healed, partial-thickness burns and compared this with the expression of these markers in matched unburned skin. This was done to assess their role in the remodeling phase of burn wound healing. ⋯ At 7 months post-burn, all growth factors studied showed a normal expression on keratinocytes. Our results suggest that keratinocytes are not only involved in re-epithelialization, but also in the scar maturation. The data support the idea that keratinocytes not only respond to cytokines and growth factors in an autocrine fashion, but also exert regulatory paracrine effects on contiguous cells.
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European cytokine network · Jun 1999
Role of interleukin-6 in a non-septic shock model induced by zymosan.
In the present study, we used IL-6 knock-out mice (IL-6KO) to evaluate a possible role of IL-6 in the pathogenesis of non-septic shock induced by peritoneal injection of zymosan. A severe inflammatory response characterized by peritoneal exudation, high peritoneal levels of nitrate/nitrite, and leukocyte infiltration into peritoneal exudate was induced by zymosan administration in wild-type control (WT) mice. This inflammatory process coincided with the damage to the lung and small intestine, as assessed by histological examination. ⋯ Furthermore, a significant reduction of suppression of mitochondrial respiration, DNA strand breakage and reduction of cellular levels of NAD+ was observed in ex vivo macrophages harvested from the peritoneal cavity of IL-6KO mice subjected to zymosan-induced non-septic shock. In vivo treatment with anti-IL-6 (5,000 ng/day per mouse, 24 and 1 hour before zymosan administration) significantly reduced the inflammatory process. Taken together, the present study clearly demonstrates that IL-6 exerts a role in zymosan-induced non-septic shock.
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European cytokine network · Jun 1999
Comparative StudyTNF-alpha and HLA-DR genotyping as potential prognostic markers in pulmonary sarcoidosis.
We have analyzed the HLA-DRB1 alleles and -308 TNF-alpha gene polymorphism in 78 sarcoidosis patients and 50 controls. The sarcoidosis group as a whole did not show any significant correlation with the TNF-A or the HLA-DR alleles compared to the control group. ⋯ In the non-Löfgren patient group, the phenotype expressing HLA-DR2 and lacking TNF-A2 was significantly higher than in the Löfgren patient group. Due to these significant genetic differences in the subgroups of Löfgren and non-Löfgren sarcoidosis patients, we conclude that the genotyping of these two loci (-308 TNF-alpha promoter polymorphism and HLA-DR) may be of prognostic value for the course of disease in sarcoidosis.
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European cytokine network · Dec 1996
Effects of methyl palmitate on cytokine release, liver injury and survival in mice with sepsis.
The effects of methyl palmitate (MP), a known inhibitor of Kupffer cells, were studied in a model of polymicrobial sepsis induced in CD-1 mice by cecal ligation and puncture (CLP). The inhibition of Kupffer cells by pretreatment with MP was shown by the reduced phagocytosis, the production of tumor necrosis factor (TNF) and interleukin-6 (IL-6) after lipopolysaccharide (LPS) challenge. ⋯ Liver toxicity was significantly reduced in MP-treated mice and survival was significantly prolonged at all intervals, reaching 45% after six to ten days compared with 3% in control mice. These findings suggest that Kupffer cells play an important role in liver damage and survival in sepsis.