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11.
Araya AV Pavez V Perez C Gonzalez F Columbo A Aguirre A Schiattino I Aguillón JC 《European cytokine network》2003,14(3):128-133
Several studies have demonstrated that diabetes is a risk factor for developing periodontal disease, increasing its prevalence and severity. Furthermore, periodontitis may impair the metabolic control and adequate treatment of diabetic patients. LPS from Gram-negative bacteria penetrates the periodontal tissues and subsequently recruits and activates immune cells. Progression to severe periodontitis with loss of supporting structures is mediated by several factors, including secretion of a broad spectrum of inflammatory and destructive (PGE2). mediators such as cytokines (TNF-alpha, IL-1b and IL-6), chemokines (IL-8) and prostaglandin E2. The aim of this work is to investigate differences in the TNF-a, IL-1b and IL-6 expression and prostaglandin E2 (PGE2) release in blood from diabetic patients with and without aggressive periodontitis (AP) stimulated with lipopolysaccharide (LPS). For this purpose we recruited 29 Type 1 diabetes mellitus (DM) patients, 14 with AP and 15 without AP. Fourteen healthy individuals formed the control group. For cytokine expression and PGE2 secretion, an ex vivo whole blood culture system was used. Cytokines and PGE2 were detected by commercial immunometric assays. A wide range of inter-individual variability in spontaneous and LPS-induced TNF-alpha, IL-1b and IL-6 levels in patient groups and controls was found. The mean of spontaneous and LPS-induced TNF-alpha and IL-1b levels did not differ significantly (p > 0.5) when patients were compared to control individuals. Although not significant, the spontaneous TNF-alpha, IL-1b and IL-6 levels in the group of Type 1 DM with AP were higher than in controls, while in diabetic patients without AP, these values were depressed in comparison with controls. In both groups of patients, the means of LPS-induced IL-6 levels were higher than the controls but the differences observed were not significant (p = 0.07). However, the LPS-induced PGE2 levels varied significantly when all groups were compared (p = 0.007). The means of LPS-induced PGE2 levels for Type 1 diabetic patients with AP (p = 0.0009) and without AP (p = 0.024) were significantly higher than the levels observed for healthy controls. Finally, we conclude that Type 1 diabetic patients with or without AP did not express higher LPS-induced TNF-a, IL-1b and IL-6 levels than controls. However, the PGE2 levels released were significantly higher than those detected in controls. 相似文献
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Several bacterial species have developed physiological response to avoid the cellular damage when are exposed to carbon starvation
or frozen stress. For example survival to inanition has been related to endogenous substrates consumptions. The aim of this
study was to evaluate if poly-β-hydroxylkanoates (PHA) consumption enable Sphingopyxis chilensis S37 to survive under carbon starvation or frozen condition. Bacterial cells were grown in R2A broth for 48 h, and suspended in mineral saline solutions, without carbon source. The cellular suspension was incubated
for 48 or 120 h at 30°C, followed by a frozen period of 48 h at −20°C, and viable bacterial cells were evaluated by the microdrop
method. The proportions of cells with PHA were also determined by flow cytometry using Nile Red dye. The results indicate
that S. chilensis were able to survive under carbon starvation and frozen conditions. Simultaneously, a decrease in the number of cells containing
PHA, and a decrease in the biovolume of the cells (c.a 2.5 times) were also observed under these conditions. The results suggest that consumptions of PHA contributed to the surviving
of S. chilensis under frozen stress. 相似文献
14.
Elizabeth Pavez Loriè Hao LiAnders Vahlquist Hans Törmä 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2009,1791(3):220-228
All-trans retinoic acid (RA) levels are controlled by enzymes of the vitamin A metabolism (RDH16, RalDH2, and LRAT) and RA catabolism (CYP26 and CYP2S1). Here, the mRNA expression of these enzymes was investigated in human keratinocytes at different Ca2+concentrations and after exposure to RA and CYP26 inhibitors. Cellular differentiation (high Ca2+) increased the expression of LRAT, RDH16 and RalDH2, and decreased CYP26B1. RA (1 μM) induced CYP26A1, CYP26B1, CYP2S1, CRABPII and LRAT mRNA. The CYP26 inhibitor talarozole altered CYP26A1 and LRAT mRNA expression in a similar way as RA, increased the cellular accumulation of [3H]RA, and induced a punctate CRABPII staining, also observed after siRNA knock-down of CYP26B1 (but not after RA exposure). Furthermore, CYP26B1 siRNA increased the accumulation of [3H]RA and the CRABPII mRNA, suggesting an augmented retinoid signalling. Thus CYP26B1 appears essential for RA catabolism under physiological conditions, whereas CYP26A1 might play a greater role during RA excess. 相似文献
15.
Antioxidant capacity of diethyldithiocarbamate in a metal independent lipid peroxidative process 总被引:3,自引:0,他引:3
2,2'-Azobis-[2-amidinopropane] initiated lipid peroxidation of egg yolk phosphatydil choline liposomes was measured by oxygen uptake and the emitted visible luminescence. Lipid peroxidation involved a chain process (kinetic chain length = 49 +/- 11) and its rate was independent of added Fe ions. Diethyldithiocarbamate (DDC) behaved as an efficient inhibitor in the microM range, being able to trap 1.05 +/- 0.25 free radicals per added molecule. The efficiency of DDC was also independent of Fe addition to the system. These results indicate that DDC is able to trap the chain carrying free radicals, showing that this compound, besides being a powerful metal chelator, is also an efficient free radical scavenger. It is proposed that the relevant step in this process involves an electron transfer from DDC to the peroxy radical LOO., LOO. + DDC- ----LOO- + DDC. followed by protonation of LOO- and dimerization of the DDC. radical. 相似文献