208 research outputs found

    Сутність та класифікація ризиків інвестиційної діяльності

    Get PDF
    Наводиться визначення поняттю "ризики інвестиційної діяльності" за рахунок поєднання його сутнісних характеристик, виконано узагальнення класифікації цих ризиків, запропоновано введення нової класифікаційної групи – "корпоративні ризики", які пов'язані з можливістю втрати контролю над підприємством інвестором-акціонером

    Integrative Analysis of Epigenetic Modulation in Melanoma Cell Response to Decitabine: Clinical Implications

    Get PDF
    Decitabine, an epigenetic modifier that reactivates genes otherwise suppressed by DNA promoter methylation, is effective for some, but not all cancer patients, especially those with solid tumors. It is commonly recognized that to overcome resistance and improve outcome, treatment should be guided by tumor biology, which includes genotype, epigenotype, and gene expression profile. We therefore took an integrative approach to better understand melanoma cell response to clinically relevant dose of decitabine and identify complementary targets for combined therapy. We employed eight different melanoma cell strains, determined their growth, apoptotic and DNA damage responses to increasing doses of decitabine, and chose a low, clinically relevant drug dose to perform whole-genome differential gene expression, bioinformatic analysis, and protein validation studies. The data ruled out the DNA damage response, demonstrated the involvement of p21Cip1 in a p53-independent manner, identified the TGFβ pathway genes CLU and TGFBI as markers of sensitivity to decitabine and revealed an effect on histone modification as part of decitabine-induced gene expression. Mutation analysis and knockdown by siRNA implicated activated β-catenin/MITF, but not BRAF, NRAS or PTEN mutations as a source for resistance. The importance of protein stability predicted from the results was validated by the synergistic effect of Bortezomib, a proteasome inhibitor, in enhancing the growth arrest of decitabine in otherwise resistant melanoma cells. Our integrative analysis show that improved therapy can be achieved by comprehensive analysis of cancer cells, identified biomarkers for patient's selection and monitoring response, as well as targets for improved combination therapy

    Advanced Computational Biology Methods Identify Molecular Switches for Malignancy in an EGF Mouse Model of Liver Cancer

    Get PDF
    The molecular causes by which the epidermal growth factor receptor tyrosine kinase induces malignant transformation are largely unknown. To better understand EGFs' transforming capacity whole genome scans were applied to a transgenic mouse model of liver cancer and subjected to advanced methods of computational analysis to construct de novo gene regulatory networks based on a combination of sequence analysis and entrained graph-topological algorithms. Here we identified transcription factors, processes, key nodes and molecules to connect as yet unknown interacting partners at the level of protein-DNA interaction. Many of those could be confirmed by electromobility band shift assay at recognition sites of gene specific promoters and by western blotting of nuclear proteins. A novel cellular regulatory circuitry could therefore be proposed that connects cell cycle regulated genes with components of the EGF signaling pathway. Promoter analysis of differentially expressed genes suggested the majority of regulated transcription factors to display specificity to either the pre-tumor or the tumor state. Subsequent search for signal transduction key nodes upstream of the identified transcription factors and their targets suggested the insulin-like growth factor pathway to render the tumor cells independent of EGF receptor activity. Notably, expression of IGF2 in addition to many components of this pathway was highly upregulated in tumors. Together, we propose a switch in autocrine signaling to foster tumor growth that was initially triggered by EGF and demonstrate the knowledge gain form promoter analysis combined with upstream key node identification

    Sources of avoidance motivation: Valence effects from physical effort and mental rotation

    Get PDF
    When reaching goals, organisms must simultaneously meet the overarching goal of conserving energy. According to the law of least effort, organisms will select the means associated with the least effort. The mechanisms underlying this bias remain unknown. One hypothesis is that organisms come to avoid situations associated with unnecessary effort by generating a negative valence toward the stimuli associated with such situations. Accordingly, merely using a dysfunctional, ‘slow’ computer mouse causes participants to dislike ambient neutral images (Study 1). In Study 2, nonsense shapes were liked less when associated with effortful processing (135° of mental rotation) versus easier processing (45° of rotation). Complementing ‘fluency’ effects found in perceptuo-semantic research, valence emerged from action-related processing in a principled fashion. The findings imply that negative valence associations may underlie avoidance motivations, and have practical implications for educational/workplace contexts in which effort and positive affect are conducive to success

    The Human Connectome Project's neuroimaging approach

    Get PDF
    Noninvasive human neuroimaging has yielded many discoveries about the brain. Numerous methodological advances have also occurred, though inertia has slowed their adoption. This paper presents an integrated approach to data acquisition, analysis and sharing that builds upon recent advances, particularly from the Human Connectome Project (HCP). The 'HCP-style' paradigm has seven core tenets: (i) collect multimodal imaging data from many subjects; (ii) acquire data at high spatial and temporal resolution; (iii) preprocess data to minimize distortions, blurring and temporal artifacts; (iv) represent data using the natural geometry of cortical and subcortical structures; (v) accurately align corresponding brain areas across subjects and studies; (vi) analyze data using neurobiologically accurate brain parcellations; and (vii) share published data via user-friendly databases. We illustrate the HCP-style paradigm using existing HCP data sets and provide guidance for future research. Widespread adoption of this paradigm should accelerate progress in understanding the brain in health and disease

    Behavioural and Developmental Interventions for Autism Spectrum Disorder: A Clinical Systematic Review

    Get PDF
    Background: Much controversy exists regarding the clinical efficacy of behavioural and developmental interventions for improving the core symptoms of autism spectrum disorders (ASD). We conducted a systematic review to summarize the evidence on the effectiveness of behavioural and developmental interventions for ASD. Methods and Findings: Comprehensive searches were conducted in 22 electronic databases through May 2007. Further information was obtained through hand searching journals, searching reference lists, databases of theses and dissertations, and contacting experts in the field. Experimental and observational analytic studies were included if they were written in English and reported the efficacy of any behavioural or developmental intervention for individuals with ASD. Two independent reviewers made the final study selection, extracted data, and reached consensus on study quality. Results were summarized descriptively and, where possible, meta-analyses of the study results were conducted. One-hundred-and-one studies at predominantly high risk of bias that reported inconsistent results across various interventions were included in the review. Meta-analyses of three controlled clinical trials showed that Lovaas treatment was superior to special education on measures of adaptive behaviour, communication and interaction, comprehensive language, daily living skills, expressive language, overall intellectual functioning and socialization. High-intensity Lovaas was superior to low-intensity Lovaas on measures of intellectual functioning in two retrospective cohort studies. Pooling the results of two randomized controlle

    HIV-1 subtype C transmitted founders modulate dendritic cell inflammatory responses

    Get PDF
    Background Heterosexual transmission remains the main route of HIV-1 transmission and female genital tract (FGT) inflammation increases the risk of infection. However, the mechanism(s) by which inflammation facilitates infection is not fully understood. In rhesus macaques challenged with simian immunodeficiency virus, dendritic cell (DC) mediated recruitment of CD4+ T cells to the FGT was critical for infection. The aim of this study was to delineate the mechanisms underlying DC-mediated HIV infection by comparing chemokine and pro-inflammatory cytokine production in response to transmitted founder (TF) and chronic infection (CI) Envelope (Env) pseudotyped viruses (PSV). Results Monocyte-derived DCs (MDDCs) were stimulated with PSV and recombinant gp140 representing matched TF and CI pairs of four individuals and cytokine secretion measured by multiplex immuno-assay. We found that 4/9 Env induced robust MDDC inflammatory responses and of those, three were cloned from TFs. Overall, TF Env induced MDDCs from healthy donors to secrete higher concentrations of inflammatory cytokines and chemokines than those from CI, suggesting TF Env were better inducers of inflammation. Assessing the signalling pathway associated with inflammatory cytokines, we found that PSV of matched TF and CI variants and a gp140 clone activated ERK and JNK to similar levels. Recombinant soluble DC-SIGN inhibited cytokine release and activation of ERK by PSV, suggesting that Env-DC-SIGN binding was partly involved in MDDC stimulation. Therefore, Env clones might differentially stimulate MDDC immune responses via alternative, yet unidentified signalling pathways. Conclusion Overall, this could suggest that the genetics of the virus itself influences inflammatory responses during HIV infection. In the absence of pre-existing infections, induction of greater inflammatory response by TFs might favour virus survival within the healthy FGT by driving an influx of target cells to sites of infection while suppressing immune responses via IL-10

    Integrating genetics and epigenetics in breast cancer: biological insights, experimental, computational methods and therapeutic potential

    Get PDF
    corecore