411 research outputs found

    On the integration of product and process models in engineering design

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    Models of products and design processes are key to interacting with engineering designs and managing the processes by which they are developed. In practice, companies maintain networks of many interrelated models which need to be synthesised in the minds of their users when considering issues that cut across them. This article considers how information from product and design process models can be integrated with a view to help manage these complex interrelationships. A framework highlighting key issues surrounding model integration is introduced and terminology for describing these issues is developed. To illustrate the framework and terminology, selected modelling approaches that integrate product and process information are discussed and organised according to their levels and forms of integration. Opportunities for further work to advance integrated modelling in engineering design research and practice are discussed

    Inhibition of invasion and metastasis of human liver cancer HCCLM3 cells by portulacerebroside A

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    CONTEXT: Portulacerebroside A (PCA) is a novel cerebroside compound isolated from Portulaca oleracea L. (Portulacaceae), an edible and medicinal plant distributed in the temperate and tropical zones worldwide. OBJECTIVE: This study investigates the effects of PCA in human liver cancer HCCLM3 cells on metastasis and invasion. MATERIALS AND METHODS: After the cells were treated with PCA (2.5, 5, and 10 μg/ml) for 6, 12, 24, or 48 h, adhesion, transwell invasion, and scratch tests were conducted and cell functions were evaluated. Western blot and FQ-RT-PCR assays explored the mechanism of PCA-inhibited invasion and metastasis in the cells. RESULTS: The adhesion rate of the cells was suppressed at 0.5 h (79.4 ± 1.0, 68.7 ± 1.3, and 58.1 ± 1.3%, versus 100 ± 1.5% in the control), 1 h (78.2 ± 1.2, 70.9 ± 1.6, and 55.4 ± 1.9%, versus 100 ± 1.2% in the control), and 1.5 h (71.6 ± 1.1, 62.3 ± 0.9, and 50.4 ± 0.9%, versus 100 ± 1.1% in the control). The 24 h invasion ability was decreased (356.6 ± 11.2, 204.0 ± 17.6, and 113.0 ± 9.5%, versus 443.6 ± 15.4% in the control). The migration capability was also restrained by PCA for 24 h (324.8 ± 25.4, 250.4 ± 21.0, and 126.3 ± 10.1, versus 381.6 ± 30.6 in the control) and 48 h (470.3 ± 34.3, 404.0 ± 19.7, and 201.0 ± 15.4, versus 752.0 ± 63.6 in the control). There was an increase in the mRNA and protein expression levels of TIMP-2 and nm23-H1, inhibition in the mRNA expression of MTA1, MMP-2, and MMP-9, and suppression in the protein expression of MTA1, RhoA, Rac1/Cdc42, MMP-2, but not RhoC and MMP-9. CONCLUSION: PCA suppresses the invasion and metastasis of HCCLM3 cells possibly by modulation of the mRNA and protein expression of related parameters. This is the first study to reveal a new potential therapeutic application of PCA in antimetastatic therapy for liver cancer

    Overexpression and Small Molecule-Triggered Downregulation of CIP2A in Lung Cancer

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    Lung cancer is the leading cause of cancer deaths worldwide, with a five-year overall survival rate of only 15%. Cancerous inhibitor of PP2A (CIP2A) is a human oncoprotein inhibiting PP2A in many human malignancies. However, whether CIP2A can be a new drug target for lung cancer is largely unclear.Normal and malignant lung tissues were derived from 60 lung cancer patients from southern China. RT-PCR, Western blotting and immunohistochemistry were used to evaluate the expression of CIP2A. We found that among the 60 patients, CIP2A was undetectable or very low in paratumor normal tissues, but was dramatically elevated in tumor samples in 38 (63.3%) patients. CIP2A overexpression was associated with cigarette smoking. Silencing CIP2A by siRNA inhibited the proliferation and clonogenic activity of lung cancer cells. Intriguingly, we found a natural compound, rabdocoetsin B which is extracted from a Traditional Chinese Medicinal herb Rabdosia coetsa, could induce down-regulation of CIP2A and inactivation of Akt pathway, and inhibit proliferation and induce apoptosis in a variety of lung cancer cells.Our findings strongly indicate that CIP2A could be an effective target for lung cancer drug development, and the therapeutic potentials of CIP2A-targeting agents warrant further investigation

    Caveolin-1 enhances resveratrol-mediated cytotoxicity and transport in a hepatocellular carcinoma model

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    <p>Abstract</p> <p>Background</p> <p>Resveratrol (RES), an estrogen analog, is considered as a potential cancer chemo-preventive agent. However, it remains unclear how RES is transported into cells. In this study, we observed that Caveolin-1(CAV1) expression can increase the cytotoxic and pro-apoptotic activity of RES in a dose- and time-dependent manner both <it>in vitro </it>and <it>in vivo </it>in a Hepatocellular Carcinoma animal model.</p> <p>Methods</p> <p>High performance liquid chromatography (HPLC) demonstrated that RES intra-cellular concentration is increased about 2-fold in cells stably expressing CAV1 or CAVM1 (a scaffolding domain (81-101AA)-defective CAV1 mutant) compared to the untransduced human Hepatoblastoma cell line (HepG2) or after transduction with the green fluorescent protein (GFP) control vector. The increased intra-cellular transport of RES was abolished in cells stably expressing CAVM2 (a cholesterol shuttle domain (143-156AA)-defective CAV1 mutant) or CAVRNAi. In order to further characterize CAV1-dependent RES transport, we synthesized RES-dansyl chloride derivatives as fluorescent probes to visualize the transport process, which demonstrated a distribution consistent with that of CAV1 in HepG2 cells.</p> <p>Results</p> <p>In addition, RES endocytosis was not mediated by estrogen receptor (ER) α and β, as suggested by lack of competitive inhibition by estrogen or Tamoxifen. Pathway analysis showed that RES can up-regulate the expression of endogenous CAV1; this activates further the MAPK pathway and caspase-3 expression.</p> <p>Discussion</p> <p>This study provides novel insights about the role played by CAV1 in modulating cellular sensitivity to RES through enhancement of its internalization and trafficking.</p

    The Survey of H5N1 Flu Virus in Wild Birds in 14 Provinces of China from 2004 to 2007

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    The highly pathogenic H5N1 avian influenza emerged in the year 1996 in Asia, and has spread to Europe and Africa recently. At present, effective monitoring and data analysis of H5N1 are not sufficient in Chinese mainland.)) were obviously higher than those in other 13 provinces. The results of sequence analysis indicated that the 17 strains isolated from wild birds were distributed in five clades (2.3.1, 2.2, 2.5, 6, and 7), which suggested that genetic diversity existed among H5N1 viruses isolated from wild birds. The five isolates from Qinghai came from one clade (2.2) and had a short evolutionary distance with the isolates obtained from Qinghai in the year 2005.We have measured the prevalence of H5N1 virus in 56 species of wild birds in 14 provinces of China. Continuous monitoring in the field should be carried out to know whether H5N1 virus can be maintained by wild birds

    Inoculations with Arbuscular Mycorrhizal Fungi Increase Vegetable Yields and Decrease Phoxim Concentrations in Carrot and Green Onion and Their Soils

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    Background As one of the most widely used organophosphate insecticides in vegetable production, phoxim (C12H15N2O3PS) is often found as residues in crops and soils and thus poses a potential threat to public health and environment. Arbuscular mycorrhizal (AM) fungi may make a contribution to the decrease of organophosphate residues in crops and/or the degradation in soils, but such effects remain unknown. Methodology/Principal Findings A greenhouse pot experiment studied the influence of AM fungi and phoxim application on the growth of carrot and green onion, and phoxim concentrations in the two vegetables and their soil media. Treatments included three AM fungal inoculations with Glomus intraradices BEG 141, G. mosseae BEG 167, and a nonmycorrhizal control, and four phoxim application rates (0, 200, 400, 800 mg l−1, while 400 mg l−1 rate is the recommended dose in the vegetable production system). Carrot and green onion were grown in a greenhouse for 130 d and 150 d. Phoxim solution (100 ml) was poured into each pot around the roots 14d before plant harvest. Results showed that mycorrhizal colonization was higher than 70%, and phoxim application inhibited AM colonization on carrot but not on green onion. Compared with the nonmycorrhizal controls, both shoot and root fresh weights of these two vegetables were significantly increased by AM inoculations irrespective of phoxim application rates. Phoxim concentrations in shoots, roots and soils were increased with the increase of phoxim application rate, but significantly decreased by the AM inoculations. Soil phosphatase activity was enhanced by both AM inocula, but not affected by phoxim application rate. In general, G. intraradices BEG 141 had more pronounced effects than G. mosseae BEG 167 on the increase of fresh weight production in both carrot and green onion, and the decrease of phoxim concentrations in plants and soils. Conclusions/Significance Our results indicate a promising potential of AM fungi for enhancing vegetable production and reducing organophosphorus pesticide residues in plant tissues and their growth media, as well as for the phytoremediation of organophosphorus pesticide-contaminated soils

    Recombinant AAV-mediated HSVtk gene transfer with direct intratumoral injections and Tet-On regulation for implanted human breast cancer

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    BACKGROUND: HSVtk/ganciclovir (GCV) gene therapy has been extensively studied in tumors and relies largely on the gene expression of HSVtk. Most studies, however, have failed to demonstrate any significant benefit of a controlled gene expression strategy in cancer treatment. The Tet-On system is commonly used to regulate gene expression following Dox induction. We have evaluated the antitumor effect of HSVtk/ganciclovir gene therapy under Tet-On regulation by means of adeno-associated virus-2 (AAV-2)-mediated HSVtk gene transfer with direct intratumoral injections in mice bearing breast cancer tumors. METHODS: Recombinant adeno-associated virus-2 (rAAV) was constructed and transduced into MCF-7 cell line. GCV treatment to the rAAV infected MCF-7 cells was performed by MTT assay under the doxycycline (Dox) induction or without Dox induction at a vp (viral particle) number of ≥10(4 )/cell. The virus was administered intratumorally to nude mice that had also received GCV intraperitoneally. The antitumor effects were evaluated by measuring tumor regression and histological analysis. RESULTS: We have demonstrated that GCV treatment to the infected MCF-7 cells under the Dox induction was of more inhibited effects than those without Dox induction at ≥10(4 )vp/cell. In ex vivo experiments, tumor growth of BALB/C nude mice breast cancer was retarded after rAAV-2/HSVtk/Tet-On was injected into the tumors under the Dox induction. Infiltrating cells were also observed in tumors after Dox induction followed by GCV treatment and cells were profoundly damaged. The expression of HSVtk gene in MCF-7 cells and BALB/C nude mice tumors was up-regulated by Tet-On under Dox induction with reverse transcription-PCR (RT-PCR) analysis. CONCLUSION: The antitumor effect of rAAV-mediated HSVtk/GCV gene therapy under the Dox induction with direct intratumoral injections may be a useful treatment for breast cancer and other solid tumors

    Synthesis of a Dual Functional Anti-MDR Tumor Agent PH II-7 with Elucidations of Anti-Tumor Effects and Mechanisms

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    Multidrug resistance mediated by P-glycoprotein in cancer cells has been a major issue that cripples the efficacy of chemotherapy agents. Aimed for improved efficacy against resistant cancer cells, we designed and synthesized 25 oxindole derivatives based on indirubin by structure-activity relationship analysis. The most potent one was named PH II-7, which was effective against 18 cancer cell lines and 5 resistant cell lines in MTT assay. It also significantly inhibited the resistant xenograft tumor growth in mouse model. In cell cycle assay and apoptosis assay conducted with flow cytometry, PH II-7 induced S phase cell cycle arrest and apoptosis even in resistant cells. Consistently revealed by real-time PCR, it modulates the expression of genes related to the cell cycle and apoptosis in these cells, which may contributes to its efficacy against them. By side-chain modification and FITC-labeling of PH II-7, we were able to show with confocal microscopy that not only it was not pumped by P-glycoprotein, it also attenuated the efflux of Adriamycin by P-glycoprotein in MDR tumor cells. Real-time PCR and western blot analysis showed that PH II-7 down-regulated MDR1 gene via protein kinase C alpha (PKCA) pathway, with c-FOS and c-JUN as possible mediators. Taken together, PH II-7 is a dual-functional compound that features both the cytotoxicity against cancer cells and the inhibitory effect on P-gp mediated drug efflux
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