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61.
To understand the seasonal migration of the anadromous Coilia nasus , we attempted to identify the parasites infecting C. nasus and determine their seasonal occurrence. From June 2007 to July 2008, a survey of 775 C. nasus individuals from the estuary of the Yangtze River and the coast of the East China Sea revealed more than 7,300 parasites associated with the gills and alimentary tracts of C. nasus . The following 6 helminth taxa were identified, i.e., the monogeneans Heteromazocraes lingmueni and Helciferus tenuis, the digenean Elytrophallus coiliae, the acanthocephalan Acanthosentis cheni , and larvae of the nematodes Anisakis simplex and Contracaecum sp., all of which are marine or brackish-water parasites. The absence of freshwater helminths suggested that the parasites acquired in freshwater may have been accidentally, and easily, lost by the time the fish had reached the estuary and coast. Contrary to seasonal occurrence of the parasites' life cycles, the lowest mean abundance and prevalence of H. lingmueni and A. cheni occurred in August, which suggested the immigration of C. nasus from freshwater to the Yangtze estuary, with lower parasite burdens. The highest mean abundance and prevalence of the nematodes A. simplex and Contracaecum sp. in May and June, and the lowest in August, indicated the arrival of the fish from the coast and the Yangtze River, to the estuary, respectively. These findings suggested that a majority of the fish prepared for spawning migration in the estuary in spring and early summer and returned to the estuary after spawning in the lower and middle reaches of the Yangtze River in late summer.  相似文献   
62.
植物富含亮氨酸重复序列型类受体蛋白激酶的生物学功能   总被引:7,自引:0,他引:7  
介绍了植物富含亮氨酸重复序列(leucine-rich repeat,LRR)型类受体蛋白激酶概念、最近发现的这类蛋白激酶的亚结构域特征;总结了目前已确定其功能的LRR型类受体蛋白激酶,并分别阐述了它们在参与植物抗逆性反应、发育调控及激素的信号转导等过程中的生物学功能;着重介绍和讨论了LRR型类受体蛋白激酶复合物之间及其与下游成分KAPP之间互作而产生信号传递的分子机理.最后展望了LRR型类受体蛋白激酶生物学功能、信号转导机制、以及应用于生产实践的研究前景.  相似文献   
63.
The microRNAs (miRNAs) are involved in multiple pathological processes among various types of tumors. However, the functions of miRNAs in benign brain tumors are largely unexplored. In order to explore the pathogenesis of the invasiveness in non-functional pituitary adenoma (NFPA), the miRNAs expression profile was analyzed between invasive and non-invasive non-functional pituitary adenoma by miRNAs microarray. Six most significant differentially expressed miRNAs were identified including four upregulated miRNAs hsa-miR-181b-5p, hsa-miR-181d, hsa-miR-191-3p, and hsa-miR-598 and two downregulated miRNAs hsa-miR-3676-5p and hsa-miR-383. The functions and corresponding signaling pathways of differentially expressed miRNAs were investigated by bioinformatics techniques, including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The result of GO analysis indicates regulation of voltage-gated potassium channel activity, positive regulation of sodium ion transport, positive regulation of GTPase activity, negative regulation of Notch signaling pathway, etc. KEGG pathway reveals a series of biological processes, including prolactin signaling pathway, endocrine and other factor-regulated calcium reabsorption, fatty acid metabolism, neuroactive ligand-receptor interaction, etc. The miRNAs hsa-miR-181a-5p was verified by quantitative real-time PCR, and the expression level was in accordance with the microarray result. Our result can provide the evidence on featured miRNAs which play a prominent role in pituitary adenoma as effective biomarkers and therapeutic targets in the future.  相似文献   
64.
目的研究中华蟾蜍消化道酸性磷酸酶(ACP)、碱性磷酸酶(ALP)、腺苷三磷酸酶(ATPase)、非特异性酯酶(NSE)、过氧化物酶(POX)和琥珀酸脱氢酶(SDH)等6种酶的分布。方法在消化道的8个部位取材,采用冰冻切片技术、石蜡切片技术、酶的组织化学方法和光密度定量分析。结果 ACP主要分布于胃贲门中贲门腺部,十二指肠和回肠中酶反应呈弱阳性。ALP主要分布于食管、十二指肠至回肠的粘膜上皮,十二指肠酶活性最高。ATPase在消化道各部位均有分布,胃中胃腺部和回肠粘膜上皮酶活性显著较高(P0.05)。NSE和POX在整个消化道粘膜上皮和粘膜固有层均有分布,胃各部位酶活性显著较低(P0.05)。SDH除在食管和直肠酶活性显著较低外,其它部位均有大量分布,十二指肠和回肠酶活性显著较高(P0.05)。结论中华蟾蜍消化道粘膜6种酶的分布同其它动物有相似之处,也有其自身特点。6种酶在消化道中的分布与消化道各部位的生理机能密切相关。  相似文献   
65.
Li C  Li Y  Xu J  Lv J  Ma Y  Shao T  Gong B  Tan R  Xiao Y  Li X 《Gene》2011,489(2):119-129
Detection of the synergetic effects between variants, such as single-nucleotide polymorphisms (SNPs), is crucial for understanding the genetic characters of complex diseases. Here, we proposed a two-step approach to detect differentially inherited SNP modules (synergetic SNP units) from a SNP network. First, SNP-SNP interactions are identified based on prior biological knowledge, such as their adjacency on the chromosome or degree of relatedness between the functional relationships of their genes. These interactions form SNP networks. Second, disease-risk SNP modules (or sub-networks) are prioritised by their differentially inherited properties in IBD (Identity by Descent) profiles of affected and unaffected sibpairs. The search process is driven by the disease information and follows the structure of a SNP network. Simulation studies have indicated that this approach achieves high accuracy and a low false-positive rate in the identification of known disease-susceptible SNPs. Applying this method to an alcoholism dataset, we found that flexible patterns of susceptible SNP combinations do play a role in complex diseases, and some known genes were detected through these risk SNP modules. One example is GRM7, a known alcoholism gene successfully detected by a SNP module comprised of two SNPs, but neither of the two SNPs was significantly associated with the disease in single-locus analysis. These identified genes are also enriched in some pathways associated with alcoholism, including the calcium signalling pathway, axon guidance and neuroactive ligand-receptor interaction. The integration of network biology and genetic analysis provides putative functional bridges between genetic variants and candidate genes or pathways, thereby providing new insight into the aetiology of complex diseases.  相似文献   
66.
PTP1B is a negative regulator of insulin signaling pathway. This study investigated the effects of compound CCF06240, a PTP1B inhibitor, on insulin sensitivity and lipid metabolic abnormalities in vivo and in vitro, respectively. The insulin resistant IRM mouse model was induced by HFD. The responses to insulin were determined by OGTT, ITT, and hyperinsulinemic-euglycemic clamp test. The body weight and the levels of serum TC and TG were measured to estimate the lipid metabolism in vivo. Recombinant human GST-PTP1B protein was used to measure the inhibition of CCF06240 on PTP1B activity. The hepatocyte lipid accumulation was induced by high concentrations of FFA and insulin in HepG(2) cells, and evaluated by the Oil Red O method. In IRM mice, the insulin resistance was improved; the body weight and the levels of TC and TG were also reduced by oral CCF06240 administration. In lipid accumulated model cells, CCF06240 was found to reverse the increased PTP1B activity, enhance the insulin-induced tyrosine phosphorylation in insulin signaling pathway, attenuate the FFA-insulin-induced cellular lipid accumulation, and down-regulate the expressions of genes related fatty acid synthesis. These results demonstrated that the PTP1B inhibitor, compound CCF06240, could increase insulin sensitivity through the regulation of insulin signaling pathway, and decrease FFA-insulin-induced hepatocytes lipid accumulation by reducing fatty acid syntheses.  相似文献   
67.
张智印  陶冶 《生命科学》2011,(7):714-722
同步辐射圆二色谱与普通圆二色谱相比,特点在于向真空紫外波段(〈200nm)拓展,以及同步辐射所提供的高强度紫外和真空紫外光源。糖的圆二色谱结构主要在200nm以下。蛋白质和核酸在200nm以下的真空紫外范围,也具有丰富的光谱结构。因此向真空紫外拓展,伴随新的电子跃迁,对应新的光谱结构,包含更丰富的结构信息,确定的结构种类就越多和越精确。同步辐射高强度的真空紫外光源,是获得高质量真空紫外圆二色谱数据的保证,为糖及糖蛋白、蛋白质和核酸研究提供了溶液中结构探测新的实验方法。综述同步辐射圆二色谱特点及其在结构生物学中的应用,以及新发展的蛋白质圆二色谱数据库(PCDDB)。介绍已对外开放的北京同步辐射实验室同步辐射圆二色谱探测,及其在蛋白质、糖和核酸研究中的应用,以及基于微流控混合芯片的亚毫秒动态探测发展。  相似文献   
68.
The C21-steroidal glycoside auriculoside A (1), recently isolated from the roots of Cynanchum auriculatum, was found to inhibit the growth of several human tumor cell lines and to induce apoptosis in human breast cancer (MCF-7) cells. Compound 1 was evaluated for its in vitro cytotoxicity against MCF-7, HO-8910, and Bel-7402 cells, and for its in vivo antitumor effects on implanted sarcoma-180 (S180) tumors in mice. It showed significant, concentration-dependent inhibition of the cancer cells, both in vitro and in vivo. MCF-7 Cells exposed to 1 displayed typical morphological apoptosis characteristics such as cytoplasm contraction and nuclear-chromatin condensation. Flow-cytometric analysis showed that the MCF-7 cell cycle was arrested at the G0/G1 phase. When treated with 40 microg/ml of 1 for 24, 48, and 72 h, respectively, the apoptotic rates of the cells were ca. 5, 8, and 18.5%, respectively.  相似文献   
69.
Self-assembly reaction of Cd(ClO4)2 · 6H2O with Norfloxacin (H-Norf) affords a novel 2D rectangular grid framework [Cd(Norf)(ClO4)(H2O)] (1) with strong blue luminescent emission (λem=425 nm), while Norf acts as a tetradentate bridging linker to connect three Cd centers and ClO4 − completes Cd center octahedron coordination geometry. The compound 1 has crystallographic data of triclinic, space group , a=9.4577(1) Å, b=9.5012(2) Å, c=12.2805(1) Å, V=3624.4(3) Å3, Z=2.  相似文献   
70.
Jang do S  Lee HJ  Lee B  Hong BH  Cha HJ  Yoon J  Lim K  Yoon YJ  Kim J  Ree M  Lee HC  Choi KY 《FEBS letters》2006,580(17):4166-4171
Failure to detect the intermediate in spite of its existence often leads to the conclusion that two-state transition in the unfolding process of the protein can be justified. In contrast to the previous equilibrium unfolding experiment fitted to a two-state model by circular dichroism and fluorescence spectroscopies, an equilibrium unfolding intermediate of a dimeric ketosteroid isomerase (KSI) could be detected by small angle X-ray scattering (SAXS) and analytical ultracentrifugation. The sizes of KSI were determined to be 18.7A in 0M urea, 17.3A in 5.2M urea, and 25.1A in 7M urea by SAXS. The size of KSI in 5.2M urea was significantly decreased compared with those in 0M and 7M urea, suggesting the existence of a compact intermediate. Sedimentation velocity as obtained by ultracentrifugation confirmed that KSI in 5.2M urea is distinctly different from native and fully-unfolded forms. The sizes measured by pulse field gradient nuclear magnetic resonance (NMR) spectroscopy were consistent with those obtained by SAXS. Discrepancy of equilibrium unfolding studies between size measurement methods and optical spectroscopies might be due to the failure in detecting the intermediate by optical spectroscopic methods. Further characterization of the intermediate using (1)H NMR spectroscopy and Kratky plot supported the existence of a partially-folded form of KSI which is distinct from those of native and fully-unfolded KSIs. Taken together, our results suggest that the formation of a compact intermediate should precede the association of monomers prior to the dimerization process during the folding of KSI.  相似文献   
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