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951.
Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF), one of the crucial pro-angiogenic factors, functions as a potent inhibitor of endothelial cell (EC) apoptosis. Previous progress has been made towards delineating the VPF/VEGF survival signaling downstream of the activation of VEGFR-2. Here, we seek to define the function of NRP-1 in VPF/VEGF-induced survival signaling in EC and to elucidate the concomitant molecular signaling events that are pivotal for our understanding of the signaling of VPF/VEGF. Utilizing two different in vitro cell culture systems and an in vivo zebrafish model, we demonstrate that NRP-1 mediates VPF/VEGF-induced EC survival independent of VEGFR-2. Furthermore, we show here a novel mechanism for NRP-1-specific control of the anti-apoptotic pathway in EC through involvement of the NRP-1-interacting protein (NIP/GIPC) in the activation of PI-3K/Akt and subsequent inactivation of p53 pathways and FoxOs, as well as activation of p21. This study, by elucidating the mechanisms that govern VPF/VEGF-induced EC survival signaling via NRP-1, contributes to a better understanding of molecular mechanisms of cardiovascular development and disease and widens the possibilities for better therapeutic targets. 相似文献
952.
Our previous studies on scalp-recorded event-related potentials (ERPs) showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA) to the ERP data, we found independent components (ICs) located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC) and the primary somatosensory cortex (SI). The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex) that are involved in sensation and perception of various stimuli. 相似文献
953.
954.
Castanea squinii Dode, an endemic tree widely distributed in China, plays an important role both in chestnut breeding and forest ecosystem
function. The spatial genetic structure within and among populations is an important part of the evolutionary and ecological
genetic dynamics of natural populations, and can provide insights into effective conservation of genetic resources. In the
present study, the spatial genetic structure of a panmictic natural population of C. sequinii in the Dabie Mountain region was investigated using microsatellite markers. Nine prescreened microsatellite loci generated
29–33 alleles each, and were used for spatial autocorrelation analysis. Based on Moran’s I coefficient, a panmictic population of C. sequinii in the Dabie Mountain region was found to be lacking a spatial genetic structure. These results suggest that a high pollen-mediated
gene flow among subpopulations counteract genetic drift and/or genetic differentiation and plays an important role in maintaining
a random and panmictic population structure in C. sequinii populations. Further, a spatial genetic structure was detected in each subpopulation’s scale (0.228 km), with all three subpopulations
showing significant fine-scale structure. The genetic variation was found to be nonrandomly distributed within 61 m in each
subpopulation (Moran’s I positive values). Although Moran’s I values varied among the different subpopulations, Moran’s I in all the three subpopulations reached the expected values with an increase in distances, suggesting a generally patchy
distribution in the subpopulations. The fine-scale structure seems to reflect restricted seed dispersal and microenvironment
selection in C. sequinii. These results have important implications for understanding the evolutionary history and ecological process of the natural
population of C. sequinii and provide baseline data for formulating a conservation strategy of Castanea species.
__________
Translated from Acta Phytoecologica Sinica, 2006, 30(1): 147–156 [译自: 植物生态学报] 相似文献
955.
Wang Juan Ni Hong Chen Li Chen Chengbin Song Wenqin 《Frontiers of Biology in China》2007,2(3):272-275
Cancer-related genes harbored in the loss regions containing a high frequency of hepatocellular carcinoma (HCC) were selected.
Related information was gathered and the coding single nucleotide polymorphism (cSNP) sequences were obtained from the single
nucleotide polymorphism (SNP) database. The appropriate primers and oligonucleotide probes were then designed in accordance
with the SNP sites, and subsequently, the gene chips for detecting SNPs were constructed. Genomic DNA was extracted from blood
samples of healthy controls and from patients with HBV infection. The sequences, including the SNPs, were amplified via polymerase
chain reaction (PCR) and labeled using digoxigenin deoxyuridine tri-phosphate (Dig-dUTP). The labeled products were then hybridized
with the SNP chips. Results confirmed that the differences in allele frequencies of three SNPs EGFL3 (rs947345), Caspase9
(rs2308950), and E2F2 (rs3218171) were distinct between HBV-infected patients and controls, suggesting that these SNPs ocuring
in high frequency in HBV-infected individuals may be associated with susceptibility to HCC.
Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis, 2006, 39(3): 1–5 [译自: 南开大学学报(自然科学版)] 相似文献
956.
Proteins are fundamental components of all living cells and the protein-protein interaction plays an important role in vital
movement. This paper briefly introduced the original Resonant Recognition Model (RRM), and then modified it by using the wavelet
transform to acquire the Modified Resonant Recognition Model (MRRM). The key characteristic of the new model is that it can
predict directly the protein-protein interaction from the primary sequence, and the MRRM is more suitable than the RRM for
this prediction. The results of numerical experiments show that the MRRM is effective for predicting the protein-protein interaction.
Translated from Journal of Shanghai University (Natural Science), 2006, 12(1): 69–73 [译自: 上海大学学报(自然科学版)] 相似文献
957.
958.
Houcong Wang Huakang Huang Simi Qiu Shi Zhang Yashun Fang Jinlei Cai Xuan Zheng Yumin Huang Ruming Chen Chuanzhi Sun Shuanglong Chen Xiaowen Chi Xinying Liao Weiqing Zhang Xinbin Zhong 《生物学前沿》2007,2(2):144-150
After 20 years of dedicated research,Jiafuzhan has been successfully developed under the new technologies in breeding high-quality early indica rice cultivars.Its rice quality has almost reached the A-level Editable Rice of Agriculture Department of China,and its average production reaches 400-500 kg/(666.7 m2).This new cultivar also has other characteristics such as enhanced resistance of blast and fallen,steady productivity,and strong adaptability.Jiafuzhan has been put into production of over 11.4×104 hm2 in Fujian Province and has been introduced and extended in other Provinces like Jiangxi,Guangdong,and Guangxi,China.The successes of breeding Jiafuzhan is a solution to the existing perennial problems in the rice industry,such as poor grain quality of big-grain rice and early indica rice,low productivity,and poor blast resistance of elite rice. 相似文献
959.
The crystal structure of uridine monophosphate kinase (UMP kinase, UMPK) from the opportunistic pathogen Ureaplasma parvum was determined and showed similar three-dimensional fold as other bacterial and archaeal UMPKs that all belong to the amino acid kinase family. Recombinant UpUMPK exhibited Michaelis-Menten kinetics with UMP, with K(m) and V(max) values of 214 +/- 4 microm and 262 +/- 24 micromol.min(-1).mg(-1), respectively, but with ATP as variable substrate the kinetic analysis showed positive cooperativity, with an n value of 1.5 +/- 0.1. The end-product UTP was a competitive inhibitor against UMP and a noncompetitive inhibitor towards ATP. Unlike UMPKs from other bacteria, which are activated by GTP, GTP had no detectable effect on UpUMPK activity. An attempt to create a GTP-activated enzyme was made using site-directed mutagenesis. The mutant enzyme F133N (F133 corresponds to the residue in Escherichia coli that is involved in GTP activation), with F133A as a control, were expressed, purified and characterized. Both enzymes exhibited negative cooperativity with UMP, and GTP had no effect on enzyme activity, demonstrating that F133 is involved in subunit interactions but apparently not in GTP activation. The physiological role of UpUMPK in bacterial nucleic acid synthesis and its potential as target for development of antimicrobial agents are discussed. 相似文献
960.