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81.
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Li S Xie L Zhang C Zhang Y Gu M Zhang R 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2004,138(3):235-243
The shells of bivalves are mainly composed of calcium carbonate, a product of calcium metabolism. In the process of shell formation, the uptake, transport and recruitment of calcium ion are highly regulated and involved in many factors. Among these regulatory factors, calmodulin (CaM), a pivotal multifunction regulator of calcium metabolism in nearly all organisms, is thought to play an important role in the calcium metabolism involved in shell formation. In this study, a full-length CaM cDNA was isolated from the pearl oyster (Pinctada fucata). The oyster calmodulin encodes a 16.8 kDa protein which shares high similarity with vertebrate calmodulin. The oyster CaM mRNA shows the highest level of expression in the gill, a key organ involved in calcium uptake in oyster calcium metabolism. In situ hybridization results revealed that oyster CaM mRNA is expressed at the folds and the outer epithelial cells of the dorsal region of the mantle, suggesting that CaM is involved in regulation of calcium transport and secretion. Oyster CaM also showed a typical Ca2+ dependent electrophoretic shift characterization and calcium binding activity. Taken together, we have identified and characterized a pivotal calcium metabolism regulator of the oyster that may play an important role in regulation of calcium uptake, transport and secretion in the process of shell formation. 相似文献
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In pharmaceutical sciences, a crucial step of the drug discovery process is the identification of drug-target interactions. However, only a small portion of the drug-target interactions have been experimentally validated, as the experimental validation is laborious and costly. To improve the drug discovery efficiency, there is a great need for the development of accurate computational approaches that can predict potential drug-target interactions to direct the experimental verification. In this paper, we propose a novel drug-target interaction prediction algorithm, namely neighborhood regularized logistic matrix factorization (NRLMF). Specifically, the proposed NRLMF method focuses on modeling the probability that a drug would interact with a target by logistic matrix factorization, where the properties of drugs and targets are represented by drug-specific and target-specific latent vectors, respectively. Moreover, NRLMF assigns higher importance levels to positive observations (i.e., the observed interacting drug-target pairs) than negative observations (i.e., the unknown pairs). Because the positive observations are already experimentally verified, they are usually more trustworthy. Furthermore, the local structure of the drug-target interaction data has also been exploited via neighborhood regularization to achieve better prediction accuracy. We conducted extensive experiments over four benchmark datasets, and NRLMF demonstrated its effectiveness compared with five state-of-the-art approaches. 相似文献
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目的:探究CT诊断对于胰腺癌侵犯胰周动静脉的临床价值。方法:随机选取在我院就诊的64例胰腺癌患者,在他们进行手术前全在距离肿瘤边缘1cm内的血管进行分期和诊断进而进行螺旋CT检查。结果:经组织学术后病理切片染色发现胰周动脉29条,静脉48条。运用外科手术探查方法发现86条胰周动脉,89条胰周静脉。在这些血管中,有23条动脉、47条静脉经外科手术证实的确是肿瘤侵犯,并且经过CT诊断,我们最终断定为有25条动脉、46条静脉处于1~4级。结论:胰周动、静脉受到侵犯时,具有不同的CT表现特征,因此在利用CT方法判断胰周动、静脉遭受侵犯时应当根据不同情况不同对待。 相似文献
87.
从簇毛麦(Haynaldia villosa (L.) Schur.)组合CA9211/RW15(6D/6V异代换系)幼胚培养SC2后代中,用原位杂交方法鉴定出T240-6为6VS端体异代换系. 以此为材料,采用微细玻璃针切割法及"单管反应"技术体系,对6VS进行切割分离及LA (Linker adaptor)-PCR扩增.扩增带在100~3 000 bp 之间,大部分集中在600~1 500 bp.利用32P标记的簇毛麦基因组为探针进行Southern杂交,证实扩增产物来源于簇毛麦.扩增产物纯化后,连接到pGEM-T载体上,构建了6VS DNA质粒文库.对文库的分析表明,文库大约有17 000个白色克隆;插入片段分布在100~1 500 bp,平均600 bp.点杂交结果表明,37%克隆有中度到强烈的杂交信号,证明含有中度或高度重复序列;63%克隆有较弱的信号或没有信号,证明为单/低拷贝序列克隆.从文库中获得8个簇毛麦特异克隆,对其中两个克隆pHVMK22和 pHVMK134进行了RFLP分析和序列分析,并利用该探针对小麦抗白粉病基因Pm21进行了检测.RFLP 结果表明,两个克隆一个为低拷贝序列克隆(pHVMK22),另一个为高度重复序列克隆,均为簇毛麦专化DNA序列.以pHVMK22为探针对抗、感病小麦(Triticum aestivum L.)品系的Southern杂交发现抗病品系有一条2 kb的特征带, 该探针可能作为检测抗病基因Pm21的探针. 相似文献
88.
女性怀孕前后饮酒会对胎儿的发育及神经系统造成不利影响,称为“胎儿酒精综合征”(fetal alcohol spectrum disorders,FASD)。小鼠通常作为研究该病的动物模型。该实验采用体外培养技术及体内冲胚法研究雌鼠怀孕前后酒精摄入对各期植入前胚胎全基因组DNAT基化模式建立的影响。小鼠植入前胚胎体外培养实验发现,体外实验组I(怀孕前酒精处理组1,除8-cell外,其他各期胚胎的DNA甲基化水平明显低于体外对照组;体外实验组II(正常胚胎在含乙醇的培养基中培养),各期植入前胚胎DNA甲基化水平均明显低于体外对照组。体内实验发现,体内实验组I(怀孕前酒精处理组)与体内的实验组II(怀孕后酒精处理组),各期植入前胚胎DNA甲基化水平明显低于体内对照组。体内、外实验结果表明:受精前后酒精对各期植入前胚胎DNA甲基化模式的正确建立造成紊乱,该结果可为进一步揭示FSAD发病机制提供一定的实验基础。 相似文献
89.
AFM对人乳腺癌细胞外纤连蛋白原纤维的形态学观察 总被引:4,自引:0,他引:4
探讨原子力显微镜在研究细胞和细胞外基质间的相互作用及细胞外基质的功能等方面的应用前景。应用原子力显微镜观察培养的人乳腺癌MCF 7 R细胞分泌的纤连蛋白原纤维的分布和排列规律 ,并与其他常规观察技术进行比较。应用原子力显微镜获得了多个乳腺癌细胞和细胞外纤连蛋白原纤维的整体和局部形貌图像 ,发现这些原纤维的分布和排列方式非常有规律 ,而且这些规律与其功能相适应。由于样品制备简单和分辨率较高等优点 ,原子力显微镜较适合于细胞外基质的原位观察 相似文献
90.
Lu H Shi B Wu G Zhang Y Zhu X Zhang Z Liu C Zhao Y Wu T Wang J Chen R 《Biochemical and biophysical research communications》2006,345(1):302-309
It has been a challenging task to integrate high-throughput data into investigations of the systematic and dynamic organization of biological networks. Here, we presented a simple hierarchical clustering algorithm that goes a long way to achieve this aim. Our method effectively reveals the modular structure of the yeast protein-protein interaction network and distinguishes protein complexes from functional modules by integrating high-throughput protein-protein interaction data with the added subcellular localization and expression profile data. Furthermore, we take advantage of the detected modules to provide a reliably functional context for the uncharacterized components within modules. On the other hand, the integration of various protein-protein association information makes our method robust to false-positives, especially for derived protein complexes. More importantly, this simple method can be extended naturally to other types of data fusion and provides a framework for the study of more comprehensive properties of the biological network and other forms of complex networks. 相似文献