Inflammatory system

Most cytokines act upon, or are produced by, leukocytes (white blood cells), which constitute the immune and inflammatory systems (Box 8.1). They thus play a central role in regulating both immune and inflammatory function and in related processes such as haematopoiesis (the production of blood cells from haematopoietic stem cells in the adult bone marrow), as well as in wound healing. Indeed, several immunosuppressive and anti-inflammatory drugs are now known to induce their biological effects by regulating production of several cytokines. 

Anti-inflammatory systemic lupus erythematosus leukemias rheumatoid arthritis breast cancer... 

Although inflammation is a self-defense operation, it may attain harmful proportions if not controlled strictly. Evolved as much as W e are, human inflammatory system still gets into the overdrive mode in several instances and instead of being efficacious, creates havoc. Neuroinflammation is one such example. Unrestricted inflammatory response in CNS is now considered a root cause of several neurodegenerative diseases, as an overdose of inflammatory moieties tend to injure/ kill neurons. 

Rheumatoid arthritis (RA). An episodic inflammatory systemic disease with autoimmune pathogenetic mechanisms. It primarily affects the joints, causing symmetrical lesions and severe damage to the affected joints. Rheumatoid arthritis is the most common form of inflammatory joint disease (prevalence about 0.5-1%). 

Numerous studies have examined the effect of metal ions on the responses of the cells of the inflammatory system. It has been noted by a number of workers that Ag concentrations, which caused a total suppression of cell activity or proliferation, were occasionally preceded by an increase in cell activity (Wataha etal. 2002, Wagner etal. 1998). The mechanism by which the metal is effective in this respect is not known, but current... 

Cytokins Several extracellular signaling proteins interact with cells of the immune or inflammatory systems by activating or modulating the proliferative properties of these cells. Cytokines that induce inflammation are pro-inflammatory mediators, whereas antiinflammatory mediators reduce it. Chemokines are cytokines that bring about local inflammation by recruiting inflammatory cells by chemotaxis and subsequently activating them. TNFa, interleukins, GM-CSF... 

In cultured rat aggregated brain cells, 10-20 nmol ochratoxin A/l was shown to increase the expression of genes involved in the brain inflammatory system (messenger ribonucleic acid [mRNA] of peroxisome proliferator-activated receptor, haem oxygenase-1 and inducible nitric oxide synthase) and to reduce the expression of glial fibrillary acidic protein, a constituent of the intermediate filaments in astrocytes (Zurich et al., 2005). 

Akagi K, Hirose M, Hoshiya T et al (1995) Modulating effects of ellagic acid, vanillin and quercetin in a rat medium term multi-organ carcinogenesis model. Cancer Lett 94 113-121 Koh MS, Willoughby DA (1979) A comparison of coumarin and levamisole on parameters of the inflammatory system. Agents Actions 9 284-288... 

Sinee the initial finding that IFN-y secretion from activated T cells can induce indirect cytotoxicity by release of reactive species (later identified as NO and per-oxynitrite) from macrophages (Nathan et al. 1983 Nathan et al. 1984) an increasing amount of data on the role of NO in the immune and inflammatory systems have accumulated. NO has been shown to influence different immune functions both during innate and adaptive immune responses, including T-ceU activation and proliferation, cytokine production, APC expansion and maturation, central and peripheral tolerance, Th cell differentiation, as well as T-ceU apoptosis (Brito et al. 1999 MacMicking et al. 1997). 

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