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The inflammatory responses induced by the synthetic polycation poly-l-arginine injected either into the pleural cavity or into the trachea in rats have been investigated. Poly-l-arginine (4–40 nmol/rat) injected intrapleurally induced exudate formation and leucocyte migration (mainly polymorphonuclear cells). The exudate formation (but not cell migration) was dependent on the molecular weight of the poly-l-arginine used (24 and 115 kD). The poly-l-arginine-induced pleurisy was mainly dependent on activation of mast cells since it was significantly reduced either in rats depleted of their stores of histamine and serotonin or in rats previously treated with the serotonin receptor antagonist methysergide. The polyanions heparin and dermatan sulphate when administered intrapleurally with the polycation markedly reduced the exudate formation. Poly-l-arginine (115 kD, 8.5 nmol/rat) injected intratracheally caused lung oedema, increased leucocyte number and protein content of bronchoalveolar lavage, respiratory insufficiency and 60% mortality in 6 h. Depletion of histamine and serotonin stores or of circulating neutrophils decreased the leucocytes in bronchoalveolar lavage but did not increase survival rate, whereas the polyanion dermatan sulphate prevented the mortality completely. These results suggest that the inflammatory changes caused by poly-l-arginine are dependent on mast cell activation but that the lethality after intratracheal administration is due to electrostatic interactions of the polycation with anionic surfaces present in the pulmonary epithelium.

Tolfenamic acid and tenidap have been reported to be dual inhibitors of cyclo-oxygenase and 5-lipoxygenase. In this study inhibition of 5-lipoxygenase by tenidap and tolfenamic acid in plasma-free leukocyte suspensions (IC50 values=10 μM) required concentrations more than 100 fold higher than those which inhibited cyclo-oxygenase (IC50 values=0.05 and 0.02 μM respectively). The potencies of tolfenamic acid and tenidap as cyclo-oxygenase inhibitors were markedly reduced in blood (IC50=6.5 and 10 μM respectively) and neither significantly inhibited 5-lipoxygenase. Since both drugs also failed to inhibit 5-lipoxygenase in rat bloodex vivo, we conclude that, at physiological levels of plasma proteins, tolfenamic acid and tenidap are selective cyclo-oxygenase inhibitors.

Mucosal-associated invariant T (MAIT) cells are unique innate-like T cells that are abundant in humans, accounting for 1-10% of circulating T cells and about 2% of total T cells in human oral cavity. MAIT cells can mount a strong immune response quickly without exogenous antigens and undergo a phenotypic transformation in the development of diseases. They produce cytokines involved in the Th1 and Th17 immune response and cytotoxic proteins, promote the dysfunction of autoreactive B cell and inhibit the function of NK cells. MAIT cells have been widely explored in autoimmune diseases, inflammatory diseases and tumors, and these mechanisms may also be involved in the pathogenesis of some oral diseases, while MAIT cells have not been systematically discussed in oral diseases. We searched PubMed/MEDLINE, EMBASE and Microsoft Bing databases to review and analyze relevant literatures on the impact of MAIT cells in the pathogenesis of human oral diseases. Collected evidence elucidated the characteristics of MAIT cells and emphasized the potential roles of MAIT cells in oral lichen planus (OLP), chronic graft-versus-host disease (cGVHD), oral squamous cell carcinoma (OSCC), apical periodontitis (AP) and primary Sjogren's syndrome (pSS).

Histamine and other mediators have been shown to be involved in the ethanol-induced jejunal plasma protein loss. In this study we have investigated whether the histamine (H)-related component of this protein loss is mediated by H1-receptors, H2-receptors or both. Four groups of dogs (n=12 in each) were studied. They were: untreated, H1+H2-receptor blockade, H1-receptor blockade and H2-receptor blockade. Chlorpheniramine and ranitidine were used to block H1 and H2-receptor blockade. Chlorpheniramine and ranitidine were used to block H1 and H2-receptors respectively. In all animals, jejunal protein loss was measured over 10 min periods for 90 min. Ethanol increased protein loss in all time periods (p<0.001). This protein loss was depressed by H1+H2-receptors blockade throughout 90 min (p<0.01). H1-receptor blockade caused a similar depression of ethanol effect but only during 20 to 40 min (p<0.05). In contrast, H2-receptor blockade aggravated the protein losing effect of ethanol throughout 90 min (p<0.01). Analyses of data tend to suggest that the ethanol-induced protein loss is mediated principally by H1-receptors, and that a complete inhibition of the histamine-related ethanol-induced protein loss can be achieved only by a simultaneous blockade of both H1 and H2- receptors, and not by H1- or H2-receptor blockade alone.

Cigarette smoke (CS)-induced inflammation is critical in chronic obstructive pulmonary disease (COPD). However, the role of acetylation at histone 3 lysine 9 (H3K9) in COPD inflammation remains unclear. The present study assessed the effect of acetylation of H3K9 on transcription both in rat lungs and in macrophages. Sprague–Dawley rats were exposed to CS for either 6 or 12 weeks and rat lungs were collected. Rat macrophages were subjected to 20 % cigarette smoke extract (CSE) for 48 h. CS increased MCP-1 and IL-8 expressions at both mRNA and protein levels in rat lungs after 6 and 12 weeks; increased TNF-α and MMP9 expressions at both levels were noted only after 12 weeks. CSE increased these genes expression in macrophages after 48 h exposure. Increased abundance of acetylated H3K9 protein in rat lungs and in macrophages were associated with decreased expression of histone deacetylase-1(HDAC1). Chromatin immunoprecipitation demonstrated increased level of acetylated H3K9 on promoter regions of these genes both in vivo and in vitro. Knockdown of HDAC1 increased these genes mRNA expression. CS increased H3K9 acetylation and subsequently altered the expression of pro-inflammatory mediators and protease genes through HDAC1 depression in CS-induced rat lungs and in macrophages.

The c.677 C > T and c.1298 A > C polymorphisms of methylenetatrahydrofolate reductase (MTHFR) gene and c.3435 C > T polymorphism of ATP-Binding cassette B1 (ABCB1) gene are reported as pharmacogenetic markers, influencing the methotrexate (MTX) therapeutic outcome in rheumatoid arthritis (RA) patients. The aims of this study were to determine the relationship between these polymorphisms and clinical response and/or adverse drug reaction (ADRs) to MTX treatment. The cohort of our study was composed of 110 RA patients of the West Algerian population. The clinical response was evaluated using the disease activity score 28 (DAS28) and the ADRs were collected after physical examination of patients. All samples were genotyped for theses polymorphisms by TaqMan® allelic discrimination assay. Based on EULAR criteria, 59.09% RA patients were responders and ADRs were observed in 40.9% patients. The frequency distribution of these three polymorphisms was similar between the responders and the non-responders. The same result was found on ADRs study and no significant difference of distribution between the presence of ADRs group and absence of ADRs group was observed. Our study joins the results that found in others population in the world. We have demonstrated, for the first time in the West Algerian population, that these polymorphisms were not predictive for clinical response and/or ADRs to MTX therapeutic outcome.