关键词： 二氢嘧啶脱氢酶   胸苷酸合成酶   c-myc   p53基因   小鼠   肝组织   昼夜节律性   基因表达   化疗  

摘要： 背景与目的:5-Fluorouracil(5-FU)主要通过抑制胸苷酸合成酶发挥抗癌作用,而二氢嘧啶脱氢酶是5-FU体内代谢的一个起始酶和限速酶。在本研究中,我们对二氢嘧啶脱氢酶、胸苷酸合成酶、c-myc和p53基因在小鼠肝脏中表达的昼夜节律进行研究。方法:本实验共采用了24只雄性B6D2F1小鼠。所有实验动物在实验中进行了4周光照同步化(12h光照:12h黑暗)。体温和休息-活动节律通过腹腔埋置的微型感受器进行动态监测。动物分别在3,7,11,15,19,23HALO(灯亮后小时数)被处死并取出肝脏冻存。肝脏标本中抽提的总RNA用LightCycler-SYBRGreenITM扩增系统进行实时定量RT-PCR。结果:小鼠的体温和休息-活动均呈现明显和相似的昼夜节律,其峰值均位于黑暗期(相当于小鼠活动相),谷值则位于光照期(相当于小鼠休息相)。二氢嘧啶脱氢酶在mRNA水平呈现出明显的昼夜节律性,其峰值时间位于16HALO左右即位于小鼠活动相(P=0.0012)。胸苷酸合成酶在mRNA水平具有昼夜节律表达的趋势,其峰值时间出现在光照期(P=0.079)。C-myc和p53在mRNA水平的节律性表达在本实验中无统计学意义。结论:二氢嘧啶脱氢酶和胸苷酸合成酶在mRNA水平呈现出昼夜节律性,二者峰值时间相差约12h,这一结果提示可以利用二者在转录水平的时间差异用5-FU进行时间化疗。

关键词： Clock基因   昼夜节律   松果体   生物钟  

摘要： 探讨 12h光照、12h黑暗交替 (LD)光制下松果体钟基因Clock是否存在昼夜节律性表达。在LD光制下饲养SD大鼠 4周后 ,在一昼夜内每隔 4h采集松果体组织 ,提取总RNA ,进行竞争性定量RT PCR ,测定不同昼夜时点(CT)样品中ClockmRNA的相对表达量。用余弦函数获取节律参数 ,并经振幅检验分析是否存在昼夜节律。结果是松果体Clock基因mRNA表达呈现昼夜节律性振荡变化 (P <0 .0 5 ) ,峰值和谷值分别位于CT18和CT6 ,峰值相位- 2 6 8.76± 2 7.6 3,振幅 0 .4 2± 0 .14 ,中值 0 .99± 0 .10。

关键词： 心血管病学   氟伐他汀   动脉粥样硬化   血压昼夜   节律   心率变异性  

摘要： 观察氟伐他汀对高血压患者颈动脉粥样硬化(CAS)及血压昼夜节律的及心率变异性(HRV)的影响.选择56例高血压患者联合治疗(氟伐他汀+苯那普利)与50例高血压患者单纯降压(苯那普利),治疗前后行彩色超声多普勒超声声像学,超声声像病理学分型;24h动态血压监测动态血压指标及HRV时域分析对照研究.结果:联合治疗组治疗前后超声声像学分型:Ⅰ、Ⅱ、Ⅲ型有显著差异(P＜0.05或＜0.01),超声声像病理学分型:扁平斑、软斑、硬斑有显著差异(P＜0.05或P＜0.01).对异常血压昼夜节律的逆转率为78%.心率变异性时域分析指标治疗前后比较有显著差异(P＜0.05).单纯降压组治疗前后,超声声像学分型Ⅰ型有显著差异(P＜0.05),超声声像病理学分型扁平斑、软斑有显著差异(P＜0.05).对异常血压昼夜节律的逆转率为64%.心率变异性分析无显著差异.联合治疗组的急性心脑血管事件的发生率为7.1%,单纯降压组的急性心脑血管事件的发生率为14%.结论:氟伐他汀对高血压患者CAS及异常血压昼夜节律的逆转、恢复自主神经及内分泌功能的平衡有着重要作用,对预防急性心脑血管事件的发生以及防止高血压患者的心、脑、肾靶器官损害有着重要意义.

关键词： circadian rhythm   gene expression   granule-bound starch synthase   nitrogen   Oryza   sugar   ADP-GLUCOSE PYROPHOSPHORYLASE   DIFFERENTIAL REGULATION   CDNA-CLONES   ISOFORMS   IDENTIFICATION   METABOLISM   PROMOTER   SEQUENCE   SUCROSE   TISSUE  

摘要： A full-length coding domain sequence of a gene analogous to granule-bound starch synthase (GBSS; ADP-glucose-starch glucosyltransferase, EC 2.***.1.21) was cloned and defined as OsGBSSII based on a Nitrogen (N)-starvation-induced cDNA library constructed using the rapid subtraction hybridization method. The deduced amino acid sequence of OsGBSSII was 62-85% identical to those of GBSS proteins from other plant species. The exon/intron organization of OsGBSSII was similar to that of OsGBSSI. OsGBSSII was mainly expressed in leaves and its protein was exclusively bound to starch granules in rice leaves, which suggests that the amylose in rice leaves is synthesized by OsGBSSII. N-starvation-induced expression of OsGBSSII could be repressed by supplying nitrate, ammonia or amino acid (glutamic acid or glutamine), glucosamine (an inhibitor of hexokinase) or dark conditions. These results indicate that N-starvation induction was dependent on the photosynthetic product and hexokinase in rice leaves. Sugars induced the accumulation of OsGBSSII transcripts in excised leaves through glycolysis-dependent pathways. OsGBSSII gene expression is regulated by the circadian rhythm in rice leaves.

关键词： 电针   自发性活动   mPer1   mPer2   昼夜节律   相位反应曲线   定量RT-PCR  

摘要： 生物节律是生命的基本属性之一.近年来的基因研究方法,使我们迎来了理解哺乳类动物昼夜节律震荡子分子基础的新纪元.果蝇与哺乳类动物一系列基因的发现,为我们提供了一个昼夜节律机制的分子框架,这个分子框架就是转录-翻译负反馈自动调节环路,它是生物节律的核心要素,这个核心要素使我们对外界授时因子的性质、光性和非光性授时因子的相位反应曲线、昼夜节律基因及其调控原理、有了新的认识.本文在我们原有研究发现针灸能调节军人昼夜节律相位的基础上,采用Aschoff的导引方法及荧光定量RT-PCR技术,就在昼夜节律时相点CTO、CT3、CT6、CT9、CT12、CT15、CT18、CT21电针、光照对金黄地鼠自发性活动昼夜节律影响及其相位反应曲线特点做了进一步深入研究,并观察了引起金黄地鼠自发性活动昼夜节律超前的CT6时相点间脑中节律基因mPer1、mPer2表达水平.实验结果显示:(1)在LD(light-dark)条件下动物的自发性活动都表现出明显的近似昼夜节律(P<0.01).(2)在DD自由运转状态下,动物的自发性活动显示出明显的近似昼夜节律(P<0.01),节律的峰相位每天向前迁移6~8度.(3)电针能调整金黄地鼠的自发性活动节律的峰相位,但有明显的依时相性,表现为在CT6刺激,峰相位向前迁移(相对迁移值为21.58度),在CT18刺激,峰相位向后迁移(相对迁移值为28.27度),其他时相点刺激无相位迁移.(4)光照能调整金黄地鼠的自发性活动节律的峰相位,也有明显的依时相性,表现为在CT15光照,峰相位向后迁移(相对迁移值为35.29度),在CT21光照,峰相位向前迁移(相对迁移值为25.53度),其他时相点光照无相位迁移.(5)电针的相位反应曲线呈现非光性.(6)在CT6电针,间脑中mPer1、mPer2基因表达水平显著降低.本研究提示电针与光照都能依时相性调节昼夜节律,但两者的作用途径与原理可能不同,因此选择合理的电针时间是应用电针治疗节律混乱与节律障碍性疾病的重要条件.

关键词： transgenic mouse   biological clock genes   retina   amacrine cell   melanopsin   circadian rhythm   MAMMALIAN RETINA   SUPRACHIASMATIC NUCLEUS   N-ACETYLTRANSFERASE   GANGLION-CELLS   XENOPUS EYE   PHOTORECEPTORS   LIGHT   LOCALIZATION   ORGANIZATION   MELATONIN  

摘要： The cellular location and rhythmic expression of Period 1 (Per1) circadian clock gene were examined in the retina of a Per1::GFP transgenic mouse. Mouse Per1 (mPer1) RNA was localized to inner nuclear and ganglion cell layers but was absent in the outer nuclear (photoreceptor) layer. Green fluorescent protein ( GFP), which was shown to colocalize with PER1 protein, was found in a few subtypes of amacrine neuron, including those containing tyrosine hydroxylase, calbindin, and calretinin, but not in cholinergic amacrine cells. A small subset of ganglion cells also contained GFP immunoreactivity (GFP-IR), but the melanopsin-containing subtype, which projects to the suprachiasmatic nuclei (SCN), lacked GFP-IR. Although the intensity of GFP-IR varied among the populations of amacrine cells at each time point that was examined, both diurnal and circadian rhythms were found for the fraction of neurons showing strong GFP-IR, with peak expression between Zeitgeber/circadian (ZT/CT) times 10 and 14. In SCNs that were examined in the same mice used for the retinal measures, the peak in GFP-IR also occurred at approximately ZT/CT10. Our results are the first to demonstrate a circadian rhythm of a biological clock component in identified neurons of a mammalian retina.

关键词： 基因组   腾冲嗜热厌氧菌   SARS早期诊断   外周生物钟  

摘要： 该论文由三部分组成:一、利用\"全基因组霰弹法测序\"策略,测定了腾冲嗜热厌氧菌(MB4<\'T>)全基因组序列.在序列初步拼接后,获得了由189个DNA contigs(DNA序列连接群)组成的基因组框架图.二、SARS是一种新发现的急性传染病,其病原体为SARS-CoV.我们对照株SARS-CoV进行了基因组序列测定,与已有的SARS-CoV全基因组序列相比,共发现137个单核苷酸突变.三、该文同时探讨了血红素对小鼠外周生物钟基因表达节律的影响.

关键词： abiotic stress   barley cathepsin-B expression   cDNA cloning   circadian rhythm   germination hormonal regulation   MOLECULAR-CLONING   HORMONAL-REGULATION   EXPRESSION PATTERN   CEREAL ALEURONE   RICE SEEDS   ZEA-MAYS   BARLEY   CDNA   PROTEINASES   WHEAT  

摘要： A barley cDNA clone encoding a putative cysteine protease with sequence homology to cathepsin B from mammalian cells has been characterized. This barley gene (CatB) is ubiquitously expressed, its mRNA being detected in leaves and roots, immature, mature and germinating embryos, in developing endosperms, and in aleurones upon germination, as assessed by northern blot analysis. The CatB mRNA expression in leaves increased by cold shock (6degreesC), was not affected by wounding, and was under circadian control. These transcripts increased in the aleurone upon germination, whereas those for a cystatin encoding gene (lcy), that inhibits commercial cathepsin B in vitro, decreased. Gibberellin (GA) treatment of isolated barley aleurones induced and abscisic acid (ABA) repressed the steady-state levels of CatB mRNA, while lcy expression had an opposite pattern of mRNA accumulation in aleurones treated with GA. No response to GA or ABA was detected in leaves.

关键词： 心电图   心率变异   血压昼夜节律   负荷值   高血压   颈动脉粥样硬化  

摘要： 目的　探讨心率变异 (HRV)、血压昼夜节律及负荷值与高血压病 (EH)颈动脉粥样硬化的关系。方法　用动态心电 (DCG)观察HRV ,用动态血压 (ABPM)观察血压昼夜节律及血压负荷值 ,用二维实时显像结合彩色双功多普勒超声检查 ,检测EH患者颈动脉粥样硬化病变程度和血流受阻程度。结果　 2 4h的HRV、血压昼夜节律及血压负荷值在EH之A、B 2组与正常对照组 (C组 )比较 ,均有统计学显著差异 ,P <0 0 1。而A、B 2组间无统计学显著性差异 (P >0 0 5 )。结论　HRV降低、血压昼夜节律消失及血压负荷值明显增高将使心脑大中血管内膜长期处于高负荷压力下 。

关键词： circadian clock   hypoxia   HIF   PAS proteins   SUPRACHIASMATIC NUCLEUS   MESSENGER-RNA   INDUCIBLE FACTOR-1-ALPHA   RHYTHMIC EXPRESSION   PERIOD HOMOLOGS   HIF-ALPHA   PROTEIN   SLEEP   CLONING   MPER2  

摘要： The key elements of circadian clockwork and oxygen homeostasis are the PAS protein family members PER and CLOCK and hypoxia-inducible factor 1 alpha (HIF-1 alpha). The PAS domain serves as an interface for protein-protein interactions. We asked whether a cross-talk exists between the PAS components of hypoxic and circadian pathways. We found several isoforms of PER1 protein that exhibit tissue-specific size differences. In the mouse brain, a predominantly nuclear 48 kDa isoform that followed a daily rhythm was observed. The 48 kDa form was found in the nuclear fractions derived from mouse liver, Swiss3T3 fibroblasts, and N2A neuroblastoma cells. In mouse kidney and human 293 kidney cells, a 55 kDa PER1 form was detected. CLOCK was observed as a predicted 100 kDa protein in rat-1 cells and in all analyzed mouse tissues including brain, liver, kidney, and spleen. In contrast to PER1, CLOCK protein expression was not rhythmic. Exposure to hypoxia led to increased PER1 and CLOCK protein levels in mice. Based on coimmunoprecipitation experiments that showed protein-protein interaction between PER1 and the a subunit of HIF-1, we suggest that these hypoxic effects may be modulated by HIF-1 alpha.