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CME‐1, a novel water‐soluble polysaccharide purified from Ophiocordyceps sinensis mycelia, has anti‐oxidative, antithrombotic and antitumour properties. In this study, other major attributes of CME‐1, namely anti‐inflammatory and immunomodulatory properties, were investigated. Treating lipopolysaccharide (LPS)‐stimulated RAW 264.7 cells with CME‐1 concentration‐dependently suppressed nitric oxide formation and inducible nitric oxide synthase (iNOS) expression. In the CME‐1‐treated RAW 264.7 cells, LPS‐induced IκBα degradation and the phosphorylation of p65, Akt and mitogen‐activated protein kinases (MAPKs), including extracellular signal‐regulated kinase, c‐Jun N‐terminal kinase and p38, were reduced. Treatment with a protein phosphatase 2A (PP2A)‐specific inhibitor, significantly reversed the CME‐1‐suppressed iNOS expression; IκBα degradation; and p65, Akt and MAPK phosphorylation. PP2A activity up‐regulation and PP2A demethylation reduction were also observed in the cells. Moreover, CME‐1‐induced PP2A activation and its subsequent suppression of LPS‐activated RAW 264.7 cells were diminished by the inhibition of ceramide signals. LPS‐induced reactive oxygen species (ROS) and hydroxyl radical formation were eliminated by treating RAW 264.7 cells with CME‐1. Furthermore, the role of ceramide signalling pathway and anti‐oxidative property were also demonstrated in CME‐1‐mediated inhibition of LPS‐activated primary peritoneal macrophages. In conclusion, CME‐1 suppressed iNOS expression by up‐regulating ceramide‐induced PP2A activation and reducing ROS production in LPS‐stimulated macrophages. CME‐1 is a potential therapeutic agent for treating inflammatory diseases.  相似文献   
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The roles of jasmonic acid (JA) and methyl jasmonate (MeJA) in improving the inducible resistance of plants to biotic and abiotic stimuli/stresses have been well investigated. However, the differences in inducing effects between exogenous applications of JA and MeJA are poorly understood. In this study, we compared the inducing effects of exogenous spray applications of 0.1 mmol/L JA and MeJA onto four un-bagged lateral branches on defense response of Larix olgensis seedlings against the gypsy moth (Lymantria dispar). The bio-activities of three major defense enzymes (SOD, PAL, and PPO) plus two protease inhibitors (TI and CI) of the unsprayed larch seedling needles, and the growth, development and reproductive capacity of the gypsy moth were examined. The results show that partial spray of JA or MeJA on L. olgensis seedlings significantly increased the bio-activities of SOD, PAL, PPO, TI, and CI (P < 0.05), and strongly decreased the larval/pupal weights and survivals, as well as the fecundity of L. dispar that fed on the seedlings relative to the control. However, the MeJA treatment showed quicker inductive effects on SOD and PAL activities; longer and more significant effects on PPO, TI, and CI activities; better inhibitory effects on the larval/pupal weights and survivals, as well as the fecundity of L. dispar than did the JA treatment. Comparatively, MeJA in the current study showed stronger effects on inducing systemic resistance to the defoliator (L. dispar) in L. olgensis than did JA.  相似文献   
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The utility of a nuclear protein-coding gene for reconstructing phylogenetic relationships within the family Culicidae was explored. Relationships among 13 species representing three subfamilies and nine genera of Culicidae were analyzed using a 762-bp fragment of coding sequence from the eye color gene, white. Outgroups for the study were two species from the sister group Chaoboridae. Sequences were determined from clone PCR products amplified from genomic DNA, and aligned following conceptual intron splicing and amino acid translation. Third codon positions were characterized by high levels of divergence and biased nucleotide composition, the intensity and direction of which varied among taxa. Equal weighting of all characters resulted in parsimony and neighboring-joining trees at odds with the generally accepted phylogenetic hypothesis based on morphology and rDNA sequences. The application of differential weighting schemes recovered the traditional hypothesis, in which the subfamily Anophelinae formed the basal clade. The subfamily Toxorhynchitinae occupied an intermediate position, and was a sister group to the subfamily Culicinae. Within Culicinae, the genera Sabethes and Tripteroides formed an ancestral clade, while the Culex-Deinocerites and Aedes- Haemagogus clades occupied increasingly derived positions in the molecular phylogeny. An intron present in the Culicinae- Toxorhynchitinae lineage and one outgroup taxon was absent in the basal Anophelinae lineage and the second outgroup taxon, suggesting that intron insertions or deletions may not always be reliable systematic characters.   相似文献   
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Fructan (polyfructosylsucrose) is an important storage carbohydrate in many plant families. fructan:fructan 6G-fructosyltransferase (6G-FFT) is a key enzyme in the formation of the inulin neoseries, a type of fructan accumulated by members of the Liliales. We have cloned the 6G-FFT from onion by screening a cDNA library using barley sucrose:fructan 6-fructosyltransferase (6-SFT) as a probe. The deduced amino acid sequence showed a high homology with plant invertases and 6-SFT. Incubation of protein extracts from transgenic tobacco plants with the trisaccharide 1-kestose and sucrose resulted in the formation of neokestose and fructans of the inulin neoseries with a degree of polymerization up to six. Introduction of the onion 6G-FFT into chicory resulted in the synthesis of fructan of the inulin neoseries, in addition to the synthesis of linear inulin.  相似文献   
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Abstract The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contained: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7% with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine.  相似文献   
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