蛋白激酶R与丙型肝炎病毒核心蛋白相互作用区域定位

目的： 观察丙型肝炎病毒（HCV）核心蛋白（CP）对蛋白激酶R(PKR)表达的影响；定位PKR与CP直接结合的区域。方法: 对Huh-7、转染表达CP的Huh-7及含有全长HCV复制子(replicon) Huh-7细胞株的PKR表达水平及干扰素（IFN）诱导前后replicon Huh-7细胞中HCV结构蛋白和非结构蛋白表达水平作比较；对CP与PKR进行免疫共沉淀试验、谷胱苷肽S转移酶（GST）结合试验。结果: Replicon Huh-7中PKR表达水平高于Huh-7及转染表达CP的Huh-7；IFN诱导后PKR表达增加，且明显抑制HCV结构和非结构蛋白的表达；PKR能与CP直接结合，依赖于PKR的N端1-180氨基酸（aa）。结论: CP能直接作用于PKR N端1-180 aa，导致PKR组成性激活，从而干扰PKR介导的相关信号转导通路。CP与PKR的相互作用是HCV病毒蛋白与细胞蛋白相互作用又一新的模式，在HCV持续感染及肝癌2者发病机制方面可能起重要作用。     

Cloning,Sequencing, Expression and Promoter Analysis of a Structural Protein of Bacteriophage MB78

Bacteriophage MB78, a virulent phage of Salmonella typhimurium isolated in our laboratory. It is different from the well-known temperate phage P22 and 9NA. A detailed physical map has been constructed. To understand more about the physiology and genetics of this interesting phage it has become necessary to fragment the phage genome, clone the fragments and analyze in depth. A number of promoters of bacteriophage MB78 have been cloned and characterized recently. As a part of this program, in this investigation, we report cloning, sequencing and expression and promoter analysis of the ClaI G fragment. We identified the expressed protein as phage structural. Phage structural proteins play a vital role in forming the core head of the phage particle.     

Identification of a Strong Promoter of Bacteriophage MB78 that Lacks Consensus Sequence Around Minus 35 Region and Interacts with Phage Specific Factor

A strong promoter of bacteriophage MB78 does not have minus 35 consensus sequence although it has a TGn motif immediately upstream of minus 10 sequence as well as the AT rich UP element. It is efficiently recognised by the sigma 70 RNA polymerase, however, a phage-specific factor competes with sigma 70 RNA polymerase for binding to this region, the binding of the factor being stronger than that of the polymerase. Contrary to the reports in the literature the polymerase appears not to bind to the UP element whereas the phage-specific factor does. The latter seems to be involved in the regulation of the promoter activity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cardiac ankyrin repeat protein is preferentially induced in atrophic myofibers of congenital myopathy and spinal muscular atrophy

Cardiac ankyrin repeat protein (CARP), which is structurally characterized by the presence of four ankyrin repeat motifs in its central region, is believed to be localized in the nucleus and to participate in the regulation of cardiac-specific gene expression in cardiomyocytes. However, we recently found that CARP was induced in skeletal muscle by denervation, leading us to speculate that CARP may be induced under some pathological conditions. In the present study, we immunohistochemically analyzed the expression of CARP in 11 cases of spinal muscular atrophy (SMA) and 14 cases of congenital myopathy. In SMA, CARP was expressed selectively in severely atrophic myofibers, suggesting that CARP expression may reflect the status of muscle atrophy. Furthermore, in the congenital myopathies, the expression patterns of CARP were distinct among the subtypes, which included nemaline myopathy, myotubular myopathy, central core disease, and congenital fiber type disproportion. Although CARP was preferentially expressed in severely damaged myofibers in nemaline myopathy, it was not detected in central core disease. These findings suggest that immunohistochemical evaluation of CARP may be helpful in the diagnosis of SMA and the congenital myopathies.     

Sleep during Ramadan intermittent fasting

During the month of Ramadan intermittent fasting, Muslims eat exclusively between sunset and sunrise, which may affect nocturnal sleep. The effects of Ramadan on sleep and rectal temperature (Tre) were examined in eight healthy young male subjects who reported at the laboratory on four occasions: (i) baseline 15 days before Ramadan (BL); (ii) on the eleventh day of Ramadan (beginning of Ramadan, BR); (iii) on the twenty-fifth day of Ramadan (end of Ramadan, ER); and (iv) 2 weeks after Ramadan (AR). Although each session was preceded by an adaptation night, data from the first night were discarded. Polysomnography was taken on ambulatory 8-channel Oxford Medilog MR-9000 II recorders. Standard electroencephalogram (EEG), electro-oculogram (EOG) and electromyogram (EMG) recordings were scored visually with the PhiTools ERA. The main finding of the study was that during Ramadan sleep latency is increased and sleep architecture modified. Sleep period time and total sleep time decreased in BR and ER. The proportion of non-rapid eye movement (NREM) sleep increased during Ramadan and its structure changed, with an increase in stage 2 proportion and a decrease in slow wave sleep (SWS) duration. Rapid eye movement (REM) sleep duration and proportion decreased during Ramadan. These changes in sleep parameters were associated with a delay in the occurrence of the acrophase of Tre and an increase in nocturnal Tre during Ramadan. However, the 24-h mean value (mesor) of Tre did not vary. The nocturnal elevation of Tre was related to a 2-3-h delay in the acrophase of the circadian rhythm. The amplitude of the circadian rhythm of Tre was decreased during Ramadan. The effects of Ramadan fasting on nocturnal sleep, with an increase in sleep latency and a decrease in SWS and REM sleep, and changes in Tre, were attributed to the inversion of drinking and meal schedule, rather than to an altered energy intake which was preserved in this study.     

Different corticostriatal projections from two parts of the cortical masticatory area in the rabbit

The cortical masticatory area (CMA) elicits rhythmic jaw movements in response to repetitive stimulation and is involved in the control of mastication. Based on jaw movement patterns, the CMA is divided into two parts. One is the part of the CMA in which a T-pattern similar to jaw movements during food transport in natural mastication is evoked by electrical stimulation. The other is more dorsomedially located, and during chewing a C-pattern similar to jaw movements can be induced. However, it is still not known which region of the putamen receives projections from the CMA and whether projections originate from both parts of the CMA. In this study, electrophysiological and histological experiments were undertaken in rabbits to investigate projections from the CMA to the putamen. Both experiments showed that the ventral region of the putamen received projections from the CMA. The density of the projections from the CMA area inducing the T-pattern seemed to be higher than that from the area inducing the C-pattern. Furthermore, the peak latency of the evoked potentials from stimulation of the CMA area inducing the T-pattern was shorter than that from stimulation of the area inducing the C-pattern. The data obtained from the present study indicate the functional role of the ventral region of the putamen in the regulation of mastication, and further suggest that the corticostriatal pathway is involved in the transition between behavioral jaw movement patterns.     

Activity of primate putamen neurons is selective to the mode of voluntary movement: visually guided,self-initiated or memory-guided

Summary The aim of this report was to investigate the neural processes of movement initiation and control in which the basal ganglia play an essential role. Single-neuron activity was recorded in the putamen of monkeys performing learned arm movements initiated in three different modes: sensorially guided, internally-timed self-initiated and memory guided. There were no significant differences in the magnitude and timing of both prime mover and supporting muscle activity between the three modes of movement. Over half of the task-related neurons showed strong activity in one of the three modes of movement initiation, but were only slightly activated in the other two modes. No clear preference for a particular movement mode was evident in the population of putamen neurons as a whole. These results are consistent with the hypothesis that there are heterogeneous groups of neurons in the putamen, and that each group of neurons participates in retrieving a different kind of information required for movement based on either external sensory events or on internally stored information.     

神经干细胞球生长动力学模型

神经干细胞的体外大规模培养对于细胞移植治疗中枢神经系统受损及各种神经退行性疾病有重大意义。体外呈球状生长的神经干细胞球在长大到一定尺寸之后，有可能在其内部由于养分缺乏而形成坏死细胞，这对于干细胞的有效扩增是极为不利的。因此，模拟神经球的动态生长过程并分析出现坏死细胞的临界神经球尺度对于神经干细胞的大规模扩增有重要意义。本研究采用元胞自动机技术建立了模拟神经球生长的动态模型，并结合神经球内养分的扩散传递模型，求解神经干细胞球内出现坏死细胞的临界神经球尺寸以及坏死细胞的扩大规律。计算结果表明，坏死细胞的出现与体外培养条件有一定关系；坏死细胞的出现主要取决于神经球的尺寸，其外部再好的培养条件也不可能抑制坏死的出现。此外，计算结果还表明，神经球内由于氧缺乏而形成的坏死细胞的出现要早于由于葡萄糖缺乏时的情况，并且坏死细胞一旦出现，其增长速度就非常快，有可能很快使整个神经球成为坏死细胞球。本研究所建立的CA模型及神经球内的传质模型可以很好的模拟神经球的生长过程。     

慢性乙型肝炎患者肝组织中HBV抗原表达特征及其临床意义

目的探讨慢性乙型病毒性肝炎肝活检组织中检测乙肝表面抗原(HBsAg)和乙肝核心抗原(HBcAg)表达强度及表达方式的必要性。方法采用EnVision免疫组织化学法检测196例慢性乙型肝炎患者肝穿组织中HBsAg和HBcAg的表达水平,并用荧光定量PCR检测其血清中的HBV DNA的含量。对肝组织进行炎症活动度分级和纤维化分期。结果肝组织中的HBsAg表达强度和表达方式与炎症分级、纤维化分期和血清乙肝病毒载量均无相关性(P>0.05)。HBcAg表达强度与炎症分级无相关性(r=-0.02,P>0.05);与纤维化分期呈负相关(r=-0.28,P<0.01);与血清乙肝病毒载量呈正相关(r=0.53,P<0.01)。HBcAg表达方式与炎症分级为负相关(r=-0.27,P<0.01),其中浆型组炎症活动度分级高于核型组和混合型组(P<0.01),混合型组高于核型组(P<0.01)。HBcAg表达方式与纤维化分期亦呈较弱的负相关(r=-0.23,P<0.01),其中浆型组纤维化分期高于核型组和混合型组(P<0.05)。HBcAg表达方式与血清乙肝病毒载量呈正相关(r=0.22,P<0.01)。结论区分肝组织中的HBsAg表达强度和表达方式无益于了解慢性乙型肝炎患者肝损害的程度,而检测肝组织中的HBcAg则有助于临床抗病毒治疗。