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为探讨仙鹤草乙醇提取物在脂多糖诱导急性肺损伤中的作用,使用NIH雄性小鼠40只,随机分为机分为空白组、模型组与实验组(相当于仙鹤草生药8g/kg组,16 g/kg组和24 g/kg组),每组8只。试验组以仙鹤草乙醇提取物连续灌胃(qd×5 d),空白组和模型组以等量N.S.灌胃。末次灌胃后以脂多糖(LPS)2.5 mg/kg气管滴注建立急性肺损伤模型。建模24 h后以酶联免疫法检测血浆前列腺素E2(PGE2)、白介素-10(IL-10)和环氧化酶-2(COX-2)含量。结果与模型组相比,仙鹤草乙醇提取物8 g/kg组,16 g/kg组和24 g/kg组血浆PGE2和COX-2水平显著降低(P<0.05)。与模型组相比,仙鹤草乙醇提取物8 g/kg、16 g/kg、24 g/kg组血浆IL-10水平显著升高(P<0.05)。结论仙鹤草乙醇提取物可能通过抑制COX-2表达,降低PGE2生成,并促进IL-10的生成对急性肺损伤产生保护作用。 相似文献
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Ana Isabel García‐Torrico Jos A. Guijarro Desire Cascales Jessica Mndez 《Journal of fish diseases》2019,42(12):1687-1696
Bacterial antibiotic resistance is one of the main healthcare problems currently. Apart from reducing antibiotic efficacy, it has awakened the interest of scientists due to its association with bacterial fitness and virulence. Interestingly, antibiotic resistance can be a source of both increased fitness and decreased fitness, even though the molecular basis of these relationships remains unknown. The aim of this work is to define the effects of sub‐MIC concentrations of cefotaxime, an antibiotic extensively used in clinical practice, on the physiology and virulence of Yersinia ruckeri and to determine the importance of these sub‐MIC concentrations for the selection of antibiotic‐resistant mutants in the aquatic environment. Results indicated that exposure to sub‐MIC concentrations of cefotaxime selected Y. ruckeri populations with irreversible alterations in the physiology, such as slow growth, aggregation in liquid cultures and modification of the colony morphology. These bacteria also displayed changes in the OMPs and LPS profiles and a full attenuation of virulence. An overexpression of the envelope stress regulator RpoE was also detected after exposure to the antibiotic. In conclusion, exposure to cefotaxime selected, at high frequency, Y. ruckeri strains that survive the antibiotic stress at the expense of a fitness cost and the loss of virulence. 相似文献
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Tania Rodríguez-Ramos Georgina Espinosa Jorge Hernández-López Jeannette Marrero Maria E. Alonso Maray Alonso 《Aquaculture (Amsterdam, Netherlands)》2008,274(1):118-125
The success of penaeid shrimp aquaculture has been limited by endemic and epidemic infectious diseases around the world and shrimp defense mechanisms are a priority for control, prevention, and diagnosis. The lethal dose (LD50) of Escherichia coli lipopolysaccharides was calculated and pathogen injection and dissolved ammonia concentration on immune response were evaluated in southern white shrimp Litopenaeus schmitti. The lethal dose of lipopolysacharides was 3.78 mg kg− 1 body weight. Injection caused changes in phenoloxidase activity in plasma and nitric oxide and total haemocyte counts within the first 24 h. High concentration of dissolved ammonia caused a decrease in haemocytes by 66% within the first 72 h, when compared to the control. Hemagglutination in plasma was not affected by injection or high concentrations of dissolved ammonia. The results showed that white shrimp recognized the lipopolysacharides and responded to this microbial elicitor, as indicated by a variety of immunological indicators and that increased dissolved ammonia affected the number of circulating haemocytes. 相似文献
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【目的】研究大肠埃希菌脂多糖(LPS)感染对乌鸡脂肪代谢及相关调控基因转录表达的影响。【方法】将120只35日龄乌鸡随机分为对照组和3个试验组(低剂量LPS组、中剂量LPS组、高剂量LPS组),试验组乌鸡每48 h注射1次不同浓度的大肠埃希菌LPS生理盐水溶液,剂量为1 mL/(只.次),低、中、高剂量LPS组乌鸡的LPS用量分别为0.25,0.5,1 mg/(kg.次),对照组注射等量生理盐水,持续2周。每次注射后12 h,用温度计测量鸡只泄殖腔温度;35,42,49日龄时称鸡体质量;49日龄时,各组随机选取10只鸡翅下静脉采血,分离血清,试剂盒检测血脂指标和脂解酶的活性,然后屠宰,取胸部肌肉、腿部肌肉和腹部脂肪计算脂肪沉积率,定量PCR检测脂肪和肌肉中脂肪代谢调控基因和脂肪酸转运调控基因的转录表达情况。【结果】试验期内LPS处理组乌鸡的泄殖腔温度极显著高于对照组;与对照组相比,LPS处理组乌鸡生产性能极显著下降;脂肪沉积量减少,肌间脂肪、皮下脂肪和腹部脂肪的含量明显降低;血清中总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)浓度极显著下降,而甘油三酯(TG)、游离脂肪酸(FFA)浓度极显著升高;LPS处理组乌鸡血清中的脂蛋白脂酶、肝脂酶和脂肪酶的活性均极显著高于对照组。定量PCR检测表明,LPS处理组乌鸡肌肉和脂肪中的脂肪合成基因FAS、ACC以及控制脂肪酸氧化的CPT-ⅠmRNA水平都显著下降,且FAS/CPT-ⅠmRNA表达水平的比率明显降低;而调控脂肪分解的LPL和控制能量稳态的PPARα的mRNA水平在低剂量LPS组明显升高,但在高剂量LPS组又显著降低;LPS处理组乌鸡的脂肪酸转运调控基因FATP1、FATP4随着LPS剂量的增大而显著降低,FABP和FAT/CD36mRNA在低剂量LPS组显著升高,但随着LPS剂量升高,其表达又降低。【结论】低剂量LPS处理减弱了乌鸡体内的脂肪生成和脂肪酸的氧化,强化了脂质的分解,而高剂量LPS全面抑制了脂肪的代谢。 相似文献
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Tenacibaculosis induction in the Senegalese sole (Solea senegalensis) and studies of Tenacibaculum maritimum survival against host mucus and plasma 
下载免费PDF全文
下载免费PDF全文 M Mabrok M Machado C R Serra A Afonso L M P Valente B Costas 《Journal of fish diseases》2016,39(12):1445-1455
Tenacibaculum maritimum, the aetiological agent for marine tenacibaculosis, is one of the most significant pathogens that threaten Senegalese sole, Solea senegalensis (Kaup), aquaculture. Because no immersion challenge with T. maritimum has been reported previously for this flatfish species, this study aimed to optimize bacterial yields as well as to establish a challenge model for tenacibaculosis induction. Several approaches were performed to optimize bacterial culture conditions, including treatment with non‐ionic surfactants, detergents, cellulase hydrolysis and strong shaking. A prolonged bath challenge was performed for 24 h under two different temperatures, 16 and 23 °C. Moreover, mucus and plasma bactericidal activities against T. maritimum were also assessed. Culturing bacteria with strong shaking and continuous shaking provided suitable culture conditions to obtain higher bacterial yields without aggregation and fluctuation, contrary to most other treatments that showed a huge amount of bacterial aggregates. A prolonged bath method for 24 h, without skin or gill scarification, was considered suitable for disease induction with high mortality rates. Moreover, data regarding mucus and plasma bactericidal activities suggested that there is a lack of host innate immune response against T. maritimum or that this particular pathogen presents evading strategies against Senegalese sole. 相似文献
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为了探讨抑制脂多糖结合蛋白(LBP)基因表达对水牛单核巨噬细胞在内毒素(LPS)诱导下炎症相关基因的表达,首先采用三质粒慢病毒包装系统包装LBP基因shRNA重组质粒pSicoR-GFP-shLBP774.利用病毒颗粒感染水牛单核巨噬细胞,进行荧光定量qRT-PCR及ELISA检测.结果显示,单核巨噬细胞在用5×108 IU/mL滴度的LBP-shRNA774慢病毒颗粒,感染指数(MOI)为300、感染7d的条件下,感染效率超过50%.qRT-PCR检测结果显示,与LPS对照组相比,shLBP774感染组可极显著抑制LBP基因的表达(p0.01),CD14,TLR4,TNF-α,IL-1β,IL-8等基因表达显著降低(p0.05).ELISA检测结果发现,与对照组相比,细胞分泌的TNF-α,IL-1β蛋白量显著降低(p0.05).以上结果表明,抑制LBP基因表达可以有效降低LPS诱导下单核巨噬细胞炎症相关基因的表达,进而调控LPS引发的炎症反应,提示可将LBP作为靶基因深入研究水牛单核巨噬细胞免疫功能和LPS致炎信号传导分子机制. 相似文献
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为探究桃色欧文氏菌脂多糖(Erwinia persicina Cp2 lipopolysaccharides, Cp2-LPSe)对紫花苜蓿(Medicago sativa)幼苗生长的影响，本研究以紫花苜蓿‘巨能551’为材料，用改良的热酚水法提取纯化Cp2-LPSe,设不同浓度(0,0.157,0.314,0.471和0.628 EU·mL-1)Cp2-LPSe处理，测定处理后种子发芽和幼苗生长指标。结果表明：改良后的热酚水法提取Cp2-LPSe的平均产率为4.27%;不同Cp2-LPSe浓度下，紫花苜蓿种子的发芽率、发芽势和发芽指数均低于对照，且发芽指数显著低于对照(P<0.05);随着Cp2-LPSe浓度的升高，幼苗的各生长指标均呈先升后降趋势，当Cp2-LPSe浓度为0.157 EU·mL-1时，各指标均达到最大值，且显著高于对照(P<0.05)。相关性和主成分分析结果表明，0.157 EU·mL-1Cp2-LPSe对紫花苜蓿幼苗生长有较大影响。综上，0.157 EU·mL-1 ... 相似文献