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Search Results: 1 - 10 of 26339 matches for " Chi-Tang Ho "
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Antioxidant Activity of Polyphenolic Compounds from Dalbergia odorifera T. Chen
Jian-Ping Hou,Hou Wu,Chi-Tang Ho,Xin-Chu Weng
Pakistan Journal of Nutrition , 2011,
Abstract: Seven compounds were isolated from Dalbergia odorifera T. Chen and their antioxidant activities were studied with Oil Stability Index (OSI) method, reducing power and radical scavenging methods. The compounds were identified by spectroscopic methods as (1) pinocembrin (2) biochanin A (3) sativanone (4) biochanin B (5) naringenin (6) 3'-hydroxymelanettin and (7) eriodictoyl. Results showed that compounds 6 and 7 exhibited stronger antioxidant activity than commonly used synthetic antioxidant BHT in the presented study.
Suppression of Heregulin-β1/HER2-Modulated Invasive and Aggressive Phenotype of Breast Carcinoma by Pterostilbene via Inhibition of Matrix Metalloproteinase-9, p38 Kinase Cascade and Akt Activation
Min-Hsiung Pan,Ying-Ting Lin,Chih-Li Lin,Chi-Shiang Wei,Chi-Tang Ho,Wei-Jen Chen
Evidence-Based Complementary and Alternative Medicine , 2011, DOI: 10.1093/ecam/nep093
Abstract: Invasive breast cancer is the major cause of death among females and its incidence is closely linked to HER2 (human epidermal growth factor receptor 2) overexpression. Pterostilbene, a natural analog of resveratrol, exerts its cancer chemopreventive activity similar to resveratrol by inhibiting cancer cell proliferation and inducing apoptosis. However, the anti-invasive effect of pterostilbene on HER2-bearing breast cancer has not been evaluated. Here, we used heregulin-β1 (HRG-β1), a ligand for HER3, to transactivate HER2 signaling. We found that pterostilbene was able to suppress HRG-β1-mediated cell invasion, motility and cell transformation of MCF-7 human breast carcinoma through down-regulation of matrix metalloproteinase-9 (MMP-9) activity and growth inhibition. In parallel, pterostilbene also inhibited protein and mRNA expression of MMP-9 driven by HRG-β1, suggesting that pterostilbene decreased HRG-β1-mediated MMP-9 induction via transcriptional regulation. Examining the signaling pathways responsible for HRG-β1-associated MMP-9 induction and growth inhibition, we observed that pterostilbene, as well as SB203580 (p38 kinase inhibitor), can abolish the phosphorylation of p38 mitogen-activated protein kinase (p38 kinase), a downstream HRG-β1-responsive kinase responsible for MMP-9 induction. In addition, HRG-β1-driven Akt phosphorylation required for cell proliferation was also suppressed by pterostilbene. Taken together, our present results suggest that pterostilbene may serve as a chemopreventive agent to inhibit HRG-β1/HER2-mediated aggressive and invasive phenotype of breast carcinoma through down-regulation of MMP-9, p38 kinase and Akt activation.
Neurotrophic Effect of Citrus 5-Hydroxy-3,6,7,8,3′,4′-Hexamethoxyflavone: Promotion of Neurite Outgrowth via cAMP/PKA/CREB Pathway in PC12 Cells
Hui-Chi Lai, Ming-Jiuan Wu, Pei-Yi Chen, Ting-Ting Sheu, Szu-Ping Chiu, Meng-Han Lin, Chi-Tang Ho, Jui-Hung Yen
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0028280
Abstract: 5-Hydroxy-3,6,7,8,3′,4′-hexamethoxyflavo?ne(5-OH-HxMF), a hydroxylated polymethoxyflavone, is found exclusively in the Citrus genus, particularly in the peels of sweet orange. In this research, we report the first investigation of the neurotrophic effects and mechanism of 5-OH-HxMF in PC12 pheochromocytoma cells. We found that 5-OH-HxMF can effectively induce PC12 neurite outgrowth accompanied with the expression of neuronal differentiation marker protein growth-associated protein-43(GAP-43). 5-OH-HxMF caused the enhancement of cyclic AMP response element binding protein (CREB) phosphorylation, c-fos gene expression and CRE-mediated transcription, which was inhibited by 2-naphthol AS-E phosphate (KG-501), a specific antagonist for the CREB-CBP complex formation. Moreover, 5-OH-HxMF-induced both CRE transcription activity and neurite outgrowth were inhibited by adenylate cyclase and protein kinase A (PKA) inhibitor, but not MEK1/2, protein kinase C (PKC), phosphatidylinositol 3-kinase (PI3K) or calcium/calmodulin-dependent protein kinase (CaMK) inhibitor. Consistently, 5-OH-HxMF treatment increased the intracellular cAMP level and downstream component, PKA activity. We also found that addition of K252a, a TrKA antagonist, significantly inhibited NGF- but not 5-OH-HxMF-induced neurite outgrowth. These results reveal for the first time that 5-OH-HxMF is an effective neurotrophic agent and its effect is mainly through a cAMP/PKA-dependent, but TrKA-independent, signaling pathway coupling with CRE-mediated gene transcription. A PKC-dependent and CREB-independent pathway was also involved in its neurotrophic action.
Nkx2.7 and Nkx2.5 Function Redundantly and Are Required for Cardiac Morphogenesis of Zebrafish Embryos
Chi-Tang Tu, Tzu-Ching Yang, Huai-Jen Tsai
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0004249
Abstract: Background Nkx2.7 is the tinman-related gene, as well as orthologs of Nkx2.5 and Nkx-2.3. Nkx2.7 and Nkx2.5 express in zebrafish heart fields of lateral plate mesoderm. The temporal and spatial expression patterns of Nkx2.7 are similar to those of Nkx2.5, but their functions during cardiogenesis remain unclear. Methodology/Principal Findings Here, Nkx2.7 is demonstrated to compensate for Nkx2.5 loss of function and play a predominant role in the lateral development of the heart, including normal cardiac looping and chamber formation. Knocking down Nkx2.5 showed that heart development was normal from 24 to 72 hpf. However, when knocking down either Nkx2.7 or Nkx2.5 together with Nkx2.7, it appeared that the heart failed to undergo looping and showed defective chambers, although embryos developed normally before the early heart tube stage. Decreased ventricular myocardium proliferation and defective myocardial differentiation appeared to result from late-stage up-regulation of bmp4, versican, tbx5 and tbx20, which were all expressed normally in hearts at an early stage. We also found that tbx5 and tbx20 were modulated by Nkx2.7 through the heart maturation stage because an inducible overexpression of Nkx2.7 in the heart caused down-regulation of tbx5 and tbx20. Although heart defects were induced by overexpression of an injection of 150-pg Nkx2.5 or 5-pg Nkx2.7 mRNA, either Nkx2.5 or Nkx2.7 mRNA rescued the defects induced by Nkx2.7-morpholino(MO) and Nkx2.5-MO with Nkx2.7-MO. Conclusions and Significance Therefore, we conclude that redundant activities of Nkx2.5 and Nkx2.7 are required for cardiac morphogenesis, but that Nkx2.7 plays a more critical function, specifically indicated by the gain-of-function and loss-of- function experiments where Nkx2.7 is observed to regulate the expressions of tbx5 and tbx20 through the maturation stage.
Zebrafish arl6ip1 Is Required for Neural Crest Development during Embryogenesis
Chi-Tang Tu, Tzu-Ching Yang, Hsing-Yen Huang, Huai-Jen Tsai
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0032899
Abstract: Background Although the embryonic expression pattern of ADP ribosylation factor-like 6 interacting protein 1 (Arl6ip1) has been reported, its function in neural crest development is unclear. Methods/Principal Findings We found that knockdown of Arl6ip1 caused defective embryonic neural crest derivatives that were particularly severe in craniofacial cartilages. Expressions of the ectodermal patterning factors msxb, dlx3b, and pax3 were normal, but the expressions of the neural crest specifier genes foxd3, snai1b, and sox10 were greatly reduced. These findings suggest that arl6ip1 is essential for specification of neural crest derivatives, but not neural crest induction. Furthermore, we revealed that the streams of crestin- and sox10-expressing neural crest cells, which migrate ventrally from neural tube into trunk, were disrupted in arl6ip1 morphants. This migration defect was not only in the trunk neural crest, but also in the enteric tract where the vagal-derived neural crest cells failed to populate the enteric nervous system. We found that this migration defect was induced by dampened Shh signaling, which may have resulted from defective cilia. These data further suggested that arl6ip1 is required for neural crest migration. Finally, by double-staining of TUNEL and crestin, we confirmed that the loss of neural crest cells could not be attributed to apoptosis. Conclusions/Significance Therefore, we concluded that arl6ip1 is required for neural crest migration and sublineage specification.
Functional characterization of cellulases identified from the cow rumen fungus Neocallimastix patriciarum W5 by transcriptomic and secretomic analyses
Tzi-Yuan Wang, Hsin-Liang Chen, Mei-Yeh J Lu, Yo-Chia Chen, Huang-Mo Sung, Chi-Tang Mao, Hsing-Yi Cho, Huei-Mien Ke, Teh-Yang Hwa, Sz-Kai Ruan, Kuo-Yen Hung, Chih-Kuan Chen, Jeng-Yi Li, Yueh-Chin Wu, Yu-Hsiang Chen, Shao-Pei Chou, Ya-Wen Tsai, Te-Chin Chu, Chun-Chieh A Shih, Wen-Hsiung Li, Ming-Che Shih
Biotechnology for Biofuels , 2011, DOI: 10.1186/1754-6834-4-24
Abstract: We have developed an efficient platform that uses a combination of transcriptomic and proteomic approaches to N. patriciarum to accelerate gene identification, enzyme classification and application in rice straw degradation. By conducting complementary studies of transcriptome (Roche 454 GS and Illumina GA IIx) and secretome (ESI-Trap LC-MS/MS), we identified 219 putative GH contigs and classified them into 25 GH families. The secretome analysis identified four major enzymes involved in rice straw degradation: β-glucosidase, endo-1,4-β-xylanase, xylanase B and Cel48A exoglucanase. From the sequences of assembled contigs, we cloned 19 putative cellulase genes, including the GH1, GH3, GH5, GH6, GH9, GH18, GH43 and GH48 gene families, which were highly expressed in N. patriciarum cultures grown on different feedstocks.These GH genes were expressed in Pichia pastoris and/or Saccharomyces cerevisiae for functional characterization. At least five novel cellulases displayed cellulytic activity for glucose production. One β-glucosidase (W5-16143) and one exocellulase (W5-CAT26) showed strong activities and could potentially be developed into commercial enzymes.Cellulosic ethanol produced by microbial fermentation from feedstocks has been proposed to replace fossil fuels in transportation. A key step in cellulosic ethanol production is to break down cellulose into glucose and hemicellulose into xylose, which can subsequently be converted into ethanol by fermentative microbes. Therefore, finding efficient cellulases is important to bioethanol production, as well as for hydrolyzing feedstocks into sugars in general. Neocallimastix species is one of the major anaerobic fungi in the rumen of water buffalo capable of efficiently digesting cellulosic biomass [1-4]. Such anaerobic fungi are potential sources for highly active cellulolytic enzymes that are useful for cellulose hydrolysis [5-7]. Plant cell wall degrading enzymes from rumen fungi such as Neocallimastix patriciarum may
Research on the allelopathic potential of wheat  [PDF]
Yau Lam, Cho Wing Sze, Yao Tong, Tzi Bun Ng, Sydney Chi Wai Tang, James Chung Man Ho, Qiaoqing Xiang, Xiao Lin, Yanbo Zhang
Agricultural Sciences (AS) , 2012, DOI: 10.4236/as.2012.38119
Abstract: Objective: This paper mainly discusses the Allelopathic potential of Wheat. Methods: This paper is prepared by reviewing the latest academic literatures. Result: The green revolution in the 1960s caused an increase in the demand for food. The agricultural sector and farmers tended to spend more time on the agricultural work but the crop yield was suppressed by the weeds. Hence, the usage of herbicide insecticides, fungicides and others chemicals had been increased. Although herbicides are efficient for weed controls, the continuous uses had gradually stimulated the weeds developing an effecttive resistance to the chemicals. Wheat (Triticum aestivum L.) is known as allelopathic against crops and weeds. Allelopathy of wheat (Triticum aestivum L.) has been extensively examined for its potentials in weeds management. The allelopathic activity of wheat has been attributed to hydroxamic acids, the related compounds and phenolic acids. Therefore, it could effectively reduce herbicide uses in order to maintain an eco-friendly environment and a cost-effective weed control.
The Effects of Social Interaction and Psychological Bias on Trading Behavior: Evidence from a Laboratory Experiment  [PDF]
Chi Ming Ho
Journal of Mathematical Finance (JMF) , 2018, DOI: 10.4236/jmf.2018.81014
Abstract: This paper details an experiment designed to explore the trading behaviors of investors that result from psychological biases and social interactions. In total, 88 investors were tracked for 6 months and 40,795 transactions were recorded. The research conducted an experimental survey and estimated a system analysis model to generate several important conclusions. First, the degree of regret bias and the disposition effects are unrelated, probably because the professional training of investors and the disposition effects are not significantly related. Second, if investors are affected by contradictions arising from their decisions, then the likelihood that they will sell a stock will decrease as the investor relationships in the community improve and the regret bias increases. Third, male investors prefer to trade derivatives, and even after controlling for the degree of regret bias, this preference is still significant.
The Hypouricemic Effect of Balanophora laxiflora Extracts and Derived Phytochemicals in Hyperuricemic Mice
Shang-Tse Ho,Yu-Tang Tung,Chi-Chang Huang,Chao-Lin Kuo,Chi-Chen Lin,Suh-Ching Yang,Jyh-Horng Wu
Evidence-Based Complementary and Alternative Medicine , 2012, DOI: 10.1155/2012/910152
Abstract: The objective of this study is to evaluate the lowering of uric acid using Balanophora laxiflora extracts and derived phytochemicals on potassium-oxonate-(PO-) induced hyperuricemia in mice. The results revealed that ethyl acetate (EtOAc) fraction of B. laxiflora extracts exhibited strong xanthine-oxidase-(XOD-) inhibitory activity. In addition, among the 10 subfractions (EA1–10) derived from EtOAc fraction, subfraction 8 (EA8) exhibited the best XOD-inhibitory activity. Four specific phytochemicals, 1-O-(E)-caffeoyl-β-D-glucopyranose (1), 1-O-(E)-p-coumaroyl-β-D-glucopyranose (2), 1,3-di-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-β-D-glucopyranose (3), and 1-O-(E)-caffeoyl-4,6-(S)-hexahydroxydiphenoyl-β-D-glucopyranose (4), were further isolated and identified from this subfraction. Compounds 3 and 4 exhibited the strongest XOD-inhibitory activity compared with other compounds, and both hydrolyzable tannins were determined to be noncompetitive inhibitors according to the Lineweaver-Burk plot. On the other hand, the in vivo hypouricemic effect in hyperuricemic mice was consistent with XOD-inhibitory activity, indicating that B. laxiflora extracts and derived phytochemicals could be potential candidates as new hypouricemic agents.
A Study of Interaction Patterns and Awareness Design Elements in a Massively Multiplayer Online Game
Tiffany Y. Tang,Cheung Yiu Man,Chu Pok Hang,Lam Shiu Cheuk,Chan Wai Kwong,Yiu Chung Chi,Ho Ka Fai,Sit Kam
International Journal of Computer Games Technology , 2008, DOI: 10.1155/2008/619108
Abstract: Massively multiplayer online games (MMOGs) have been known to create rich and versatile social worlds for thousands of millions of players to participate. As such, various game elements and advance technologies such as artificial intelligence have been applied to encourage and facilitate social interactions in these online communities, the key to the success of MMOGs. However, there is a lack of studies addressing the usability of these elements in games. In this paper, we look into interaction patterns and awareness design elements that support the awareness in LastWorld and FairyLand. Experimental results obtained through both in-game experiences and player interviews reveal that not all awareness tools (e.g., an in-game map) have been fully exploited by players. In addition, those players who are aware of these tools are not satisfied with them. Our findings suggest that awareness-oriented tools/channels should be easy to interpret and rich in conveying “knowledge” so as to reduce players-cognitive overload. These findings of this research recommend considerations of early stage MMOG design.
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