92 research outputs found

    The role of cytochrome c oxidase subunit Va in non-small cell lung carcinoma cells: association with migration, invasion and prediction of distant metastasis

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    BACKGROUND: Lung cancer is one of the most lethal malignancies worldwide, but useful biomarkers of lung cancer are still insufficient. The aim of this study is to identify some membrane-bound protein(s) associated with migration and invasion in human non-small cell lung cancer (NSCLC) cells. METHODS: We classified four NSCLC cell lines into high and low migration/invasion groups by Transwell and Matrigel assays. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), we identified 10 membrane-associated proteins being significantly overexpressed in the high migration/invasion group. The expression of the target protein in the four NSCLC cell lines was then confirmed by reverse transcription polymerase chain reaction (RT-PCR), western blot and immunostaining. RNA interference technique was applied to observe the influence of the target protein on migration and invasion. Gelatin zymography was also performed to evaluate the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Expression condition of the target protein on surgical specimens was further examined by immunohistochemical staining and the clinicopathologic data were analyzed. RESULTS: We identified a mitochondria-bound protein cytochrome c oxidase subunit Va (COX Va) because of its abundant presence found exclusively in tumorous areas. We also demonstrated that migration and invasion of NSCLC cells decreased substantially after knocking down COX Va by siRNA. Meanwhile, we found a positive correlation between COX Va expression, Bcl-2 expression and activities of MMP-2 and MMP-9 in NSCLC cells. Immunohistochemical staining of surgically resected lung adenocarcinomas in 250 consecutive patients revealed that strong COX Va expression was found in 54.8% (137/250) of patients and correlated positively with the status of lymph node metastasis (P = 0.032). Furthermore, strong COX Va expression was associated with the presence of distant metastasis (P = 0.033). CONCLUSIONS: Our current study showed that COX Va may play a role in migration and invasion of NSCLC cells and can be used as a biomarker to predict aggressiveness of NSCLC

    Hypermethylation of the TGF-β target, ABCA1 is associated with poor prognosis in ovarian cancer patients

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    Background The dysregulation of transforming growth factor-β (TGF-β) signaling plays a crucial role in ovarian carcinogenesis and in maintaining cancer stem cell properties. Classified as a member of the ATP-binding cassette (ABC) family, ABCA1 was previously identified by methylated DNA immunoprecipitation microarray (mDIP-Chip) to be methylated in ovarian cancer cell lines, A2780 and CP70. By microarray, it was also found to be upregulated in immortalized ovarian surface epithelial (IOSE) cells following TGF-β treatment. Thus, we hypothesized that ABCA1 may be involved in ovarian cancer and its initiation. Results We first compared the expression level of ABCA1 in IOSE cells and a panel of ovarian cancer cell lines and found that ABCA1 was expressed in HeyC2, SKOV3, MCP3, and MCP2 ovarian cancer cell lines but downregulated in A2780 and CP70 ovarian cancer cell lines. The reduced expression of ABCA1 in A2780 and CP70 cells was associated with promoter hypermethylation, as demonstrated by bisulfite pyro-sequencing. We also found that knockdown of ABCA1 increased the cholesterol level and promoted cell growth in vitro and in vivo. Further analysis of ABCA1 methylation in 76 ovarian cancer patient samples demonstrated that patients with higher ABCA1 methylation are associated with high stage (P = 0.0131) and grade (P = 0.0137). Kaplan-Meier analysis also found that patients with higher levels of methylation of ABCA1 have shorter overall survival (P = 0.019). Furthermore, tissue microarray using 55 ovarian cancer patient samples revealed that patients with a lower level of ABCA1 expression are associated with shorter progress-free survival (P = 0.038). Conclusions ABCA1 may be a tumor suppressor and is hypermethylated in a subset of ovarian cancer patients. Hypermethylation of ABCA1 is associated with poor prognosis in these patients

    Will Japan, Taiwan or the US be isolated by China? A macroeconomic game approach

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    In Taiwan, Japan and even the United States, economic isolation has become a major concern due to the growing Chinese economy, which may lead to welfare losses for the isolated countries. On the basis of the framework developed by Plasmans et al. [Plasmans, J., Engwerda, J., van Aarle, B., Di Bartolomeo, G., Michalak, T., 2005. Dynamic Modelling of Monetary and Fiscal Cooperation Among Nations. Springer], this paper establishes a four-player game with an open-loop information structure to measure possible losses by an international policy coordination approach instead of the conventional free trade agreements. We simulate macroeconomic adjustments of the four countries according to the different institutional scenarios and economic shocks. The baseline simulation and sensitivity analyses indicate that Taiwan can get benefit by participating in coalitional mechanisms including China. In addition, most of the feasible policy coalitions cannot come into effect without US participation. This implies that at the current stage the US rather than China should be the main economic partner of Taiwan and Japan to prevent them from being economically marginalized.Economic isolation East Asia Policy coordination Macroeconomic game

    ERM crisis in retrospect: What if a European central bank had been in existence before 1992?

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    This paper explores whether policy coordination or a single monetary policy implemented earlier would have kept the U.K. in the process of European monetary integration. On the basis of the pre-ERM crisis empirics by Douven and Plasmans (1996), a counterfactual game simulation approach is used, and five scenarios are established for comparison with the actual historical records. The final answer is negative.Counterfactual analysis European Monetary System Currency crisis

    A Socio-technical assessment of the success of picture archiving and communication systems: the radiology technologist’s perspective

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    BACKGROUND: With the increasing prevalence of Picture Archiving and Communication Systems (PACS) in healthcare institutions, there is a growing need to measure their success. However, there is a lack of published literature emphasizing the technical and social factors underlying a successful PACS. METHODS: An updated Information Systems Success Model was utilized by radiology technologists (RTs) to evaluate the success of PACS at a large medical center in Taiwan. A survey, consisting of 109 questionnaires, was analyzed by Structural Equation Modeling. RESULTS: Socio-technical factors (including system quality, information quality, service quality, perceived usefulness, user satisfaction, and PACS dependence) were proven to be effective measures of PACS success. Although the relationship between service quality and perceived usefulness was not significant, other proposed relationships amongst the six measurement parameters of success were all confirmed. CONCLUSIONS: Managers have an obligation to improve the attributes of PACS. At the onset of its deployment, RTs will have formed their own subjective opinions with regards to its quality (system quality, information quality, and service quality). As these personal concepts are either refuted or reinforced based on personal experiences, RTs will become either satisfied or dissatisfied with PACS, based on their perception of its usefulness or lack of usefulness. A satisfied RT may play a pivotal role in the implementation of PACS in the future

    Garcinol Attenuates Lipoprotein(a)-Induced Oxidative Stress and Inflammatory Cytokine Production in Ventricular Cardiomyocyte through α7-Nicotinic Acetylcholine Receptor-Mediated Inhibition of the p38 MAPK and NF-κB Signaling Pathways

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    Garcinol, a nicotinic acetylcholine receptor (nAChR) antagonist, has recently been established as an anti-inflammation agent. However, the molecular mechanism by which garcinol suppresses inflammation in the context of acute myocardial infarction (AMI) remains unclear. Hypothesis: We hypothesized that the administration of physiological doses of garcinol in mice with isoproterenol-induced AMI decreased the effect of lipoprotein(a) (Lp(a))-induced inflammation both in vivo and in vitro via the α7-nAChRs mediated p38 mitogen-activated protein kinase (MAPK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) signaling pathway. We analyzed altered reactive oxygen species (ROS) generation, the production of superoxide by mitochondria, cytokine expression patterns, and the role of the p38 MAPK/NF-κB signaling pathway after Lp(a)-stimulated human ventricular cardiomyocyte AC16 cells were treated with increasing doses of garcinol. C-reactive protein (CRP), interleukin (IL)-1β, IL-6, or tumor necrosis factor (TNF)-α production were detected by enzyme-linked immunosorbent assay. The Cell Counting Kit-8 assay was used to evaluate drug cytotoxicity. Western blots and confocal fluorescence microscopy were used to determine altered expression patterns of inflammatory biomarkers. We also examined whether the therapeutic effect of garcinol in AMI was mediated in part by α7-nAChR. Lp(a)-induced inflammatory cardiomyocytes had increased expression of membrane-bound α7-nAChRs in vitro and in vivo. Low-dose garcinol did not affect cardiomyocyte viability but significantly reduced mitochondrial ROS, CRP, IL-1β, IL-6, and TNF-α production in Lp(a)-stimulated cardiomyocytes (p < 0.05). The Lp(a)-induced phosphorylation of p38 MAPKs, CamKII, and NFκB, as well as NFκB-p65 nuclear translocation, was also suppressed (p < 0.05) by garcinol, while the inhibition of p38 MAPK by the inhibitor SB203580 decreased the phosphorylation of extracellular signal-regulated kinase (ERK) and p38 MAPK. Garcinol protected cardiomyocytes by inhibiting apoptosis and inflammation in mice with AMI. Furthermore, garcinol also enhanced the expression of microRNA-205 that suppressed the α7-nAChR-induced p38 MAPK/NF-κB signaling pathway. Garcinol suppresses Lp(a)-induced oxidative stress and inflammatory cytokines by α7-nAChR-mediated inhibition of p38 MAPK/NF-κB signaling in cardiomyocyte AC16 cells and isoproterenol-induced AMI mice

    Treatment, Outcome, and Relapse of Spontaneous and Nonspontaneous Cerebrospinal Fluid Leak

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    Cerebrospinal fluid (CSF) leak can be spontaneous or nonspontaneous. The management options include conservative treatments, blood patch, and surgical repairs. We compared clinical symptoms, image findings, management options, hospitalization, and relapse rates among different causes of CSF leaks. Eighty-one patients were recruited: 20 with spontaneous and 61 with nonspontaneous CSF leaks. Nonspontaneous causes included lumbar puncture, surgery, and trauma. Surgery sites comprised sphenoid, spine, skull base, and calvaria. Spontaneous CSF leak came from the sphenoid or spine. Age, gender, body mass index, initial symptoms, hospitalization, treatment courses, and recurrence rates showed no difference between the groups. The spontaneous group had higher CSF accumulations on their MRIs. MRI pachymeninge enhancement showed the highest sensitivity (78.6%) for intracranial hypotension. Meningitis occurred in 1/3 of sphenoid, skull base, and calvarian surgeries. Earlier reoperation was correlated with shorter hospitalization (r = 0.651), but the recurrence rates were similar. Longer intervals between surgery and CSF leak encouraged reoperation. Among the spontaneous spine and lumbar puncture-related CSF leaks, 57.1% of them responded to 4 days of conservative treatment. Among the trauma-related CSF leaks, 90.9% of them required surgical repair. The demographic data and symptoms were similar in various groups of CSF leak. The symptom onset durations and treatment strategies were different. However, the recurrence rates were similar
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