关键词： 昼夜节律   视交叉上核   加压素   原位杂交   MRNA  

摘要： 目的　探讨人视交叉上核加压素mRNA表达与昼夜节律的关系。方法　采用原位杂交和生物图像分析技术定量分析 2 5例受试者 ,视交叉上核加压素mRNA表达水平。结果　人视交叉上核加压素mRNA表达呈现明显的昼夜变化 ,白天加压素mRNA表达水平比夜间高 40 %。结论　人视交叉上核加压素mRNA的昼夜节律性表达可能是在基因水平调控人体生物节律的重要机制之一。

关键词： 颈动脉粥样硬化   动态血压   昼夜节律  

摘要： 目的　了解颈动脉粥样硬化患者血压昼夜节律的变化 ,并与颈动脉正常组比较。方法　用彩色多普勒超声诊断仪及动态血压监测仪检测了 92名高血压病患者的颈动脉内膜情况及动态血压值 ,并进行统计学分析。结果　颈动脉粥样硬化 (CAS)组的 2 4小时平均收缩压 (2 4小时MSP)、白天平均收缩压 (dMSP)、夜间平均收缩压 (nMSP)明显高于颈动脉正常 (CAN)组 (P <0 0 1) ;颈动脉粥样硬化 (CAS)组的非杓型血压检出率高于颈动脉正常 (CAN)组 ,(P <0 0 5 ) ,颈动脉粥样硬化 (CAS)和颈动脉正常 (CAN)两组患者的 2 4小时平均舒张压 (2 4小时MDP)、白天及夜间平均舒张压 (dMDP、nMDP)未检出显著性差异 (P >0 0 5 )。结论　颈动脉粥样硬化患者的平均收缩压较对照组升高 ,且血压昼夜节律异常的检出率亦高于对照组。

关键词： .Synthetase   Diel   Carboxylase/Oxygenase  

摘要： Diel periodicity in the expression of key genes involved in carbon and nitrogen assimilation in marine Synechococcus spp. was investigated in a natural population growing in the surface waters of a cyclonic eddy in the northeast Atlantic Ocean. Synechococcus sp. cell concentrations within the upper mixed layer showed a net increase of three- to fourfold during the course of the experiment (13 to 22 July 1991), the population undergoing approximately one synchronous division per day. Consistent with the observed temporal pattern of phycoerythrin (CpeBA) biosynthesis, comparatively little variation was found in cpeBA mRNA abundance during either of the diel cycles investigated. In marked contrast, the relative abundance of transcripts originating from the genes encoding the large subunit of ribulose bisphosphate carboxylase/oxygenase (rbcL) and glutamine synthetase (glnA) showed considerable systematic temporal variation and oscillated during the course of each diel cycle in a reciprocal rhythm. Whereas activation of rbcL transcription was clearly not light dependent, expression of glnA appeared sensitive to endogenous changes in the physiological demands for nitrogen that arise as a natural consequence of temporal periodicity in photosynthetic carbon assimilation. The data presented support the hypothesis that a degree of temporal separation may exist between the most active periods of carbon and nitrogen assimilation in natural populations of marine Synecoccoccus spp.

关键词： 动脉血压监测   高血压   颈动脉粥样硬化   超声分型  

摘要： 目的:探讨血压昼夜节律、血压负荷值与高血压病颈动脉粥样硬化的超声分型关系。方法:对94例高血压病患者超声检查双侧颈动脉,同时结合动态血压监测。结果:随着高血压病期增加,颈总动脉内径(CADIA)也增加,粥样硬化病变的超声分型均与正常对照组有明显差别(P<0.01),并且与血压昼夜节律及血压负荷值异常相关。结论:动态血压负荷值及血压昼夜节律对评估高血压病颈动脉粥样硬化的斑块发生率和预后有重要临床意义。

关键词： 昼夜节律   生物节律   生物钟基因   小鼠   小家鼠   生物学研究   定位  

摘要： 时间生物学研究的新突破：小鼠昼夜节律生物钟基因的定位据美国Ｊｏｓｅｐｈ．Ｓ．Ｔａｋａｈａｓｈｉ等在“Ｓｃｉｅｎｃｅ”上报道，他们用Ｎ－乙基－Ｎ－亚硝基脉（ＥＮＵ）处理的小鼠后代筛选昼夜节律生物钟基因突变，鉴定出控制昼夜节律周期及维持节律性生物钟的半显...

关键词： Animals   Base Sequence   Blotting, Northern   Blotting, Northern   Circadian Rhythm   Drosophila melanogaster/genetics   Drosophila melanogaster/physiology   Drosophila Proteins   Drosophila Proteins   Female   Gene Expression   Genotype   Immunohistochemistry   Immunohistochemistry   Locomotion   Male   Molecular Sequence Data   Nervous System Physiological Phenomena   Nuclear Proteins   Period Circadian Proteins   Plasmids   Proteins/genetics   Proteins/physiology   Transcription, Genetic   Transformation, Genetic  

摘要： The per gene of D. melanogaster influences or participates in the generation of biological rhythms. Previous experiments have identified the head as the location from which per exerts its effect on circadian rhythms. To localize further this region and to examine the effects of altered levels and altered spatial expression patterns of the per gene on circadian rhythms of locomotor activity, we have characterized transformed lines containing per gene constructs missing substantial cis-acting regulatory information. The data suggest that wild-type levels of per gene expression are necessary in only a small fraction of the nervous system for near wild-type periods, whereas a larger fraction of per-expressing cells in the brain contributes to the strength of the circadian rhythms.

关键词： Science   Humanities and Social Sciences   multidisciplinary  

摘要： The per locus of Drosophila melanogaster has a fundamental role in the construction or maintenance of a biological clock. Three classes of per mutations have been identified: perl mutants have circadian behavioural rhythms with a 29-h rather than a 24-h period, pers mutants have short-period rhythms of 19 h, and per0 mutants have no detectable circadian rhythms1–4. Each of these mutations has a corresponding influence on the 55-s periodicity of male courtship song5. Long-and short-period circadian rhythm phenotypes can also be obtained by altering the dosage of the wild-type gene4: for example, females carrying only one dose of this X-linked gene have circadian rhythms with periodicities about 1 h longer than those carrying two doses. In a previous report6, cloned DNA was used to localize several chromosomal rearrangement breakpoints that alter per locus function. The rearrangements all affected a 7-kilobase (kb) interval that encodes a 4.5-kb poly(A)+ RNA. We report here that when a 7.1-kb fragment from a per+ fly, including the sequences encoding the 4.5-kb transcript, is introduced into the genome of a per0 (arrhythmic) fly by P element-mediated transformation, circadian rhythmicity of behaviour such as eclosion and locomotor activity is restored. The transforming DNA complements per locus deletions and is transcribed, forming a single 4.5-kb poly(A)+ RNA comparableto that produced by wild-type flies.