952 research outputs found

    Volatility of the Utilities Industry: Its Causal Relationship to Other Nine Industries

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    The goal of this study is to investigate the causality relationship between the Utilities industry and the nine other industries. Previous literatures show that volatility of stock prices is informative; Granger causality is applied in this research by using of a leveraged bootstrap test developed by Hacker and Hatemi-J (2006) to examine the behavior of the volatility. The results indicate that causality of the volatility of the Utilities industry on the volatility of seven other industries, except the Information Technology and Telecommunication Services industries. The data also suggest that Financials industry has impact on the Utilities industry

    A Microwave-Assisted Extraction Method for Determining Hot Water Solubility of Wood

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    A microwave-assisted extraction method is proposed as an alternative to the conventional method for determining the hot water solubility of wood. In this alternative method, microwave heating substitutes for the boiling water to extract part of the extraneous components as well as starches in wood tissues. Experimental results indicate that 100 mL water can be heated to boiling in only 75 s under the microwave radiation. Hence, only 15-20 min are required to complete the extraction procedure for Liquidambar formosana Hance and Swietenia mahagoni Jacq., 10 min and 5 min for Taiwania cryptomerioides and Cunninghamia lanceolata (Lamb) Hook, respectively. In general, a 15-min microwave heating has the potential to be an alternative to the conventional method, which requires 3 h for the hot water solubility determination

    Pronounced activation of protein kinase C, ornithine decarboxylase and c-jun proto-oncogene by paraquat-generated active oxygen species in WI-38 human lung cells

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    AbstractParaquat (methyl viologen, PQ) is a widely used herbicide that produces oxygen-derived free radicals and severely injures human lungs. In this study we examined the effects of PQ on the protein kinase C (PKC), ornithine decarboxylase (ODC) and c-jun oncogene expression in WI-38 human lung cells. Exposure of cells to 25–200 μM PQ resulted in an increase of [3H]phorbol dibutyrate (PDBu) binding and PKC redistribution in a dose-dependent manner. Interestingly, a superoxide dismutase mimic, 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol, 2.5 mM) and catalase (400 μg/ml) could significantly reduce the PQ-stimulated increase of phorbol ester binding and particular PKC phosphorylatiog activity, but dimethylsulfoxide (DMSO, 1.5%), an effective ·OH trapping agent, failed to prevent this stimulation. In addition, an endogenous substrate of PKC, 80 kDa protein, was found to be highly phosphorylated in intact WI-38 cells treated with 50 AM PQ. The increase of phosphorylated proteins could be completely or partly abolished by Tempol or catalase, but only the phosphorylation of 80 kDa protein was diminished by protein kinase C inhibitor, 1-(5-isoquinolinyl-sulfonyl)-2-methylpiperazine (H-7). A maximal peak of ODC activity was observed at 6 h of treatment with 50 μM PQ. PQ induced activity was reduced at the following rates, Tempol 85%, DMSO 80% and catalase 45%, but H-7 failed to do so. Furthermore, we found that the level of c-jun mRNA was transiently increased by PQ and the peak appeared at 1 h of treatment. When correlated with the PKC result, Tempol, catalase and H-7 all effectively blocked PQ-elicited c-jun transcript expression, but DMSO only exhibited a weakly inhibitory effect. We therefore propose that superoxide anion (O2− and H2O2 generated by PQ could activate PKC and lead to induction of c-jun gene expression; on the other hand, O2− and ·OH might trigger other kinase pathways to elevate ODC activity. Finally, the sequential expression of c-jun oncogene, and ODC may cooperate to relieve the oxidative damages elicited by PQ

    Effect of bis(hydroxymethyl) alkanoate curcuminoid derivative MTH-3 on cell cycle arrest, apoptotic and autophagic pathway in triple-negative breast adenocarcinoma MDA-MB-231 cells: An in vitro study

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    Curcumin has been shown to exert potential antitumor activity in vitro and in vivo involved in multiple signaling pathways. However, the application of curcumin is still limited because of its poor hydrophilicity and low bio-availability. In the present study, we investigated the therapeutic effects of a novel and water soluble bis(hydroxymethyl) alkanoate curcuminoid derivative, MTH-3, on human breast adenocarcinoma MDA-MB-231 cells. This study investigated the effect of MTH-3 on cell viability, cell cycle and induction of autophagy and apoptosis in MDA-MB-231 cells. After 24-h treatment with MTH-3, a concentration-dependent decrease in MDA-MB-231 cell viability was observed, and the IC50 value was 5.37±1.22 μM. MTH-3 significantly triggered G2/M phase arrest and apoptosis in MDA-MB-231 cells. Within a 24-h treatment, MTH-3 decreased the CDK1 activity by decreasing CDK1 and cyclin B1 protein levels. MTH-3-induced apoptosis was further confirmed by morphological assessment and Annexin V/PI staining assay. Induction of apoptosis caused by MTH-3 was accompanied by an apparent increase of DR3, DR5 and FADD and, as well as a marked decrease of Bcl-2 and Bcl-xL protein expression. MTH-3 also decreased the protein levels of Ero1, PDI, PERK and calnexin, as well as increased the expression of IRE1α, CHOP and Bip that consequently led to ER stress and MDA-MB-231 cell apoptosis. In addition, MTH-3-treated cells were involved in the autophagic process and cleavage of LC3B was observed. MTH-3 enhanced the protein levels of LC3B, Atg5, Atg7, Atg12, p62 and Beclin-1 in MDA-MB-231 cells. Finally, DNA microarray was carried out to investigate the level changes of gene expression modulated by MTH-3 in MDA-MB-231 cells. Taken together, our results suggest that MTH-3 might be a novel therapeutic agent for the treatment of triple-negative breast cancer in the near future

    Transcriptional regulation of FoxO3 gene by glucocorticoids in murine myotubes.

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    Glucocorticoids and FoxO3 exert similar metabolic effects in skeletal muscle. FoxO3 gene expression was increased by dexamethasone (Dex), a synthetic glucocorticoid, both in vitro and in vivo. In C2C12 myotubes the increased expression is due to, at least in part, the elevated rate of FoxO3 gene transcription. In the mouse FoxO3 gene, we identified three glucocorticoid receptor (GR) binding regions (GBRs): one being upstream of the transcription start site, -17kbGBR; and two in introns, +45kbGBR and +71kbGBR. Together, these three GBRs contain four 15-bp glucocorticoid response elements (GREs). Micrococcal nuclease (MNase) assay revealed that Dex treatment increased the sensitivity to MNase in the GRE of +45kbGBR and +71kbGBR upon 30- and 60-min Dex treatment, respectively. Conversely, Dex treatment did not affect the chromatin structure near the -17kbGBR, in which the GRE is located in the linker region. Dex treatment also increased histone H3 and/or H4 acetylation in genomic regions near all three GBRs. Moreover, using chromatin conformation capture (3C) assay, we showed that Dex treatment increased the interaction between the -17kbGBR and two genomic regions: one located around +500 bp and the other around +73 kb. Finally, the transcriptional coregulator p300 was recruited to all three GBRs upon Dex treatment. The reduction of p300 expression decreased FoxO3 gene expression and Dex-stimulated interaction between distinct genomic regions of FoxO3 gene identified by 3C. Overall, our results demonstrate that glucocorticoids activated FoxO3 gene transcription through multiple GREs by chromatin structural change and DNA looping

    Efficacy of Mammographic Evaluation of Breast Cancer in Women Less Than 40 Years of Age: Experience from a Single Medical Center in Taiwan

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    Background/PurposeMammography is the standard imaging modality for breast cancer diagnosis. However, the value of mammographic diagnosis in breast cancer patients aged less than 40 years old has not been well assessed. The goal of our study was to determine the diagnostic efficacy of mammography for the detection of breast cancer in women under 40 years of age in a single medical center in Taiwan.MethodsOf 1766 women diagnosed with breast cancer in one medical center between 1999 and 2005, 227 (12.9%) who were younger than 40 years of age were enrolled, and 105 of these 227 patients had pre-biopsy mammograms available for analysis. The sensitivities for mammography at first (prospective) and second (retrospective) readings and for corresponding ultrasound were calculated. The distribution of different breast composition between the mammographic true-positive (TP) and false-negative (FN) lesions at the first and second readings was analyzed.ResultsOf the 105 patients, 104 presented with a palpable mass and the other one was asymptomatic. There were 109 pathologically proven breast cancers from the 105 patients; 92 of 109 cancerous lesions were detected at the first mammographic reading (sensitivity 84.4%), and the most common mammographic sign was microcalcifications (40.2%). The second reading detected seven additional cancers (99 of 109 lesions; sensitivity 90.8%). There was no significant difference between mammographic TP and FN lesions for the different breast composition on first and second readings. Ninety patients also had ultrasound available for correlation with 94 cancers diagnosed from them. The diagnostic sensitivity of ultrasound was 94.7% (89 of 94 lesions).ConclusionMammography has an acceptable sensitivity for the detection of breast cancer in women aged less than 40 years, regardless of different breast composition. Breast ultrasound can offer a higher sensitivity for such a population
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