关键词： AICAR   Adenylate levels   ATP   Metabolism   Cell stasis   Biostabilization   ACTIVATED PROTEIN-KINASE   KILLIFISH AUSTROFUNDULUS-LIMNAEUS   SANDWICH CONFIGURATION   COLLAGEN SANDWICH   RAT HEPATOCYTES   ENERGY-CHARGE   INHIBITION   DEPRESSION   TOLERANCE   DIAPAUSE  

摘要： In species whose evolutionary history has provided natural tolerance to dehydration and freezing, metabolic depression is often a pre-requisite for survival. We tested the hypothesis that preconditioning of mammalian cells with 5-aminoimidazole-4-carboxamide-1-b-o-ribofuranoside (AICAR) to achieve metabolic depression will promote greater survivorship during cryopreservation. AICAR is used extensively to stimulate AMP-activated protein kinase (AMPK), which can result in downregulation of biosynthetic processes. We showed that the metabolic interconversion of AICAR was cell-type dependent. Accumulation of 5-aminoimidazole-4-carboxamide-1b-D-ribofuranosyl-5'-monophosphate (ZMP), as well as other metabolites that possess multiple phosphates (i.e., ZDP, ZTP), varied approximately 3.5-fold across the cell lines tested. AICAR treatment also significantly influenced the concentrations of cellular adenylates (ATP, ADP, and AMP). Depression of cell metabolism and proliferation with AICAR treatment differed among cell lines. Proliferation for a given cell line was negatively correlated with the fold-increase achieved in the 'effective adenylate ratio' ([AMP] + [ZMP])/[ATP]) after AICAR treatment. Metabolic preconditioning with AICAR promoted a significant increase in viability post-freezing in J774.A1 macrophages, HepG2/C3A cells and primary hepatocytes but not in NIH/3T3 fibroblasts or OMK cells. The effect of AICAR on viability after freezing was positively correlated (r(2) = 0.94) with the fold-increase in the 'effective adenylate ratio'. Thus for each cell line, the greater the depression of metabolism and proliferation due to preconditioning with AICAR, the greater was the survivorship post-freezing. (C) 2010 Elsevier Inc. All rights reserved.

关键词： 体外循环   深低温停循环   预处理   肺缺血预处理   缺血再灌注损伤  

摘要： 目的探讨肺缺血预处理在深低温停循环(DHCA)中对肺组织的保护作用。方法 18只幼猪随机根据DHCA前预处理方式分为缺血预处理组(n=6)、联合预处理组(缺血缺氧预处理,n=6)和对照组(不予预处理,n=6)。检测三组体外循环前和体外循环结束即刻(体外循环后)肺静态顺应性、肺血管阻力指数、肺湿干质量比以及左心房与肺动脉肿瘤坏死因子α(TNF-α)、白介素(IL)8、10(IL-8、IL-10)浓度比值(TNF-α、IL-8、IL-10相对含量);取左下肺叶组织,HE染色光学显微镜观察肺组织水肿和炎症细胞浸润情况。结果体外循环前三组间各项指标比较差异无统计学意义;体外循环后,联合预处理组肺静态顺应性高于其他两组(P<0.05);缺血预处理组、联合预处理组肺血管阻力指数和IL-8、IL-10相对含量以及联合预处理组的肺湿干质量比均显著小于对照组(P<0.05)。与体外循环前比较,体外循环后三组肺静态顺应性降低,肺湿干质量比显著增大,TNF-α、IL-8、IL-10相对含量增加(均P<0.05);对照组和缺血预处理组肺血管阻力指数增加(P<0.05),而联合预处理组体外循环前后肺血管阻力指数比较差异无统计学意义(P>0.05)。组织学观察显示,与对照组和缺血预处理组相比,联合预处理组肺组织水肿和白细胞浸润程度较轻。结论肺缺血预处理可减轻DHCA缺血再灌注对肺组织的损伤。与单纯肺缺血预处理相比,肺缺血联合缺氧预处理对肺组织保护作用更佳。

关键词： 异氟烷   缺血预处理   低温,人工   心肌再灌注损伤  

摘要： 目的 评价异氟烷预处理联合浅低温对大鼠离体心脏缺血再灌注损伤的影响.方法 雄性SD大鼠50只,体重250～300 g,随机分为5组（n=10）：正常对照组（C组）、缺血再灌注组（I/R组）、异氟烷预处理组（P组）、浅低温组（M组）和异氟烷预处理联合浅低温组（PM组）.制备离体心脏Langendorff灌注模型,各组经主动脉灌注K-H液,平衡灌注20 min后,C组继续灌注K-H液120 min,其余各组制备缺血再灌注模型;I/R组和P组常温（37 ℃）缺血30 min时进行再灌注;M组和PM组浅低温（31 ℃）缺血30 min时进行再灌注.P组和PM组于缺血前用1.0%异氟烷预充饱和的K-H液灌注15 min,再用K-H液冲洗15 min.分别于平衡灌注20 min、缺血前即刻、再灌注30、60 min时记录左室舒张末期压、左心室收缩压、左室压最大上升速率、左室压最大下降速率和HR.再灌注60min时取心肌组织,测定心肌梗死体积、心肌细胞线粒体和胞浆的细胞色素C水平.电镜下观察心肌细胞线粒体形态.结果 与I/R组比较,P组、M组和PM组再灌注期间心功能改善,心肌梗死体积缩小,心肌细胞胞浆细胞色素C水平降低,心肌细胞线粒体细胞色素C水平升高（P＜0.05或0.01）;与P组比较,PM组再灌注期间心功能改善,心肌梗死体积缩小,心肌细胞胞浆细胞色素C水平降低,心肌细胞线粒体胞色素C水平升高（P＜0.05）;与M组比较,PM组心肌细胞胞浆细胞色素C水平降低,心肌细胞线粒体细胞色素C水平升高（P＜0.05或0.01）.电镜下PM组线粒体损伤轻于I/R组、P组和M组.结论 异氟烷预处理联合浅低温减轻大鼠心肌缺血再灌注损伤的效应强于异氟烷预处理或浅低温,其机制与减少心肌细胞线粒体细胞色素C的扩散,保护心肌细胞有关.

关键词： 烟草   出苗率   低温处理   花药培养  

摘要： 为了研究低温预处理不同时间对烟草花药培养胚状体诱导率的影响,以烟草K326×GDH黄叶突变体组合的F2、F3和F4植株的花药为试验材料,在接种前将花药用4℃低温预冷处理24h、48h和72h后,在(26±1)℃条件下进行花药培养。结果表明,烟草花药经4℃低温预处理48h后接种,可明显提高花药胚状体的诱导率,最佳培养世代为F2。

关键词： 预处理   农业秸秆   低温热解   可磨性   可行性  

摘要： 农作物秸秆类生物质水分含量高、能量密度低、资源分散,因此储存运输成本高,而且可磨性差不易制粉用于煤粉锅炉或气化炉的混合燃烧与气化。生物质低温预处理技术是一种能够解决上述问题的温和热解方法,它能够显著改善生物质的特性。选取棉花秆和小麦秆在固定床实验台上N2氛围下分别升温至200℃、250℃、300℃热解,加热时间均为30 m in。制得的生物质半焦能量密度显著提高,对比原始的生物质其可磨性得到明显改善,并且具有了疏水性,便于储存运输或制粉用于气流床气化。最后根据实验结果进行预处理技术的可行性分析,推荐预处理条件为250℃、30 m in。

关键词： Behavioral aging   Lifespan   Dietary restriction   Mild stress   Fungal infection   Heat stress   Cold stress   Drosophila melanogaster   YOUNG AGE   HYPERGRAVITY EXPOSURE   FOOD RESTRICTION   MILD STRESS   LIFE   HEAT   INFECTION   NUTRITION   SHOCKS   FLIES  

摘要： A cold pretreatment has various positive effects on aging, longevity, and resistance to some stresses in Drosophila melanogaster flies. Removing live yeast from food has either favorable or deleterious effects on these traits. This study combined a cold pretreatment and removal of live yeast in the same flies, in order to know whether higher favorable effects would be observed with this combination than with each treatment alone. Each treatment had positive effects on climbing activity and their combination had additive effects, thus giving the highest climbing scores in flies subjected to the two treatments and the lowest ones in flies with live yeast and no cold pretreatment. Therefore, combining the two treatments had favorable effects if each of them had favorable effects. When removing live yeast had very deleterious effects, as on resistance to cold, a cold pretreatment was unable to reverse these effects, which was not unexpected. Finally, when removal had no effect or not a tragic negative effect, as on resistance to infection or to heat, a cold pretreatment was neutral or slightly compensated the negative effects of live yeast removal. These results lead to the conclusion that next studies using a combination of two mild stresses having beneficial effects on aging and longevity could bring more positive effects than each mild stress alone.

关键词： 聚木糖酶   预处理   碱性过氧化氢   常压   低温   棉浆  

摘要： 采用聚木糖酶预处理和碱性过氧化氢常压低温蒸漂相结合的制浆工艺进行了棉浆的生产性应用,从蒸漂效果、半浆物理指标、废液指标等方面与传统的高温高压蒸漂锅制浆系统进行了对比分析。

关键词： 刺梨   花药离体培养   低温预处理   小孢子   发育途径  

摘要： 为明确低温预处理对刺梨花药离体培养过程中小孢子发育及愈伤组织诱导率的影响,进行低温预处理试验,结果表明:离体培养条件下,刺梨雄核存在3条发育途径,即A-V途径、A-G途径和B途径,以A途径为主;随着培养时间的增加,小孢子逐渐退化,低温预处理3d可在一定程度上延缓刺梨小孢子退化,提早雄核发育,并增加参与雄核发育小孢子数量,提高花药愈伤组织诱导率。

关键词： 低温预处理   花毛茛   种子   萌发  

摘要： 以花毛茛杂交种子为材料,研究在(–1±0.2)、(2±0.2)、(5±0.2)℃条件下分别冷贮15、30、45d对种子萌发的影响.结果表明,低温预处理对花毛茛种子萌发有显著的促进作用,与对照相比,T1t2预处理的种子萌发效果最显著(P<0.01),萌芽势提高了37.70%,萌芽率提高了21.60%,种子活力指数增强了0.36.