314 research outputs found

    Treatment implications of predominant polarity and the polarity index: a comprehensive review.

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    Background: Bipolar disorder (BD) is a serious and recurring condition that affects approximately 2.4% of the global population. About half of BD sufferers have an illness course characterized by either a manic or a depressive predominance. This predominant polarity in BD may be differentially associated with several clinical correlates. The concept of a polarity index (PI) has been recently proposed as an index of the antimanic versus antidepressive efficacy of various maintenance treatments for BD. Notwithstanding its potential clinical utility, predominant polarity was not included in the DSM-5 as a BD course specifier. Methods: Here we searched computerized databases for original clinical studies on the role of predominant polarity for selection of and response to pharmacological treatments for BD. Furthermore, we systematically searched the Pubmed database for maintenance randomized controlled trials (RCTs) for BD to determine the PI of the various pharmacological agents for BD. Results: We found support from naturalistic studies that bipolar patients with a predominantly depressive polarity are more likely to be treated with an antidepressive stabilization package, while BD patients with a manic-predominant polarity are more frequently treated with an antimanic stabilization package. Furthermore, predominantly manic BD patients received therapeutic regimens with a higher mean PI. The calculated PI varied from 0.4 (for lamotrigine) to 12.1 (for aripiprazole). Conclusions: This review supports the clinical relevance of predominant polarity as a course specifier for BD. Future studies should investigate the role of baseline, predominant polarity as an outcome predictor of BD maintenance RCTs. Keywords

    Chemical genetics approach to restoring p27Kip1 reveals novel compounds with antiproliferative activity in prostate cancer cells

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    <p>Abstract</p> <p>Background</p> <p>The cyclin-dependent kinase (CDK) inhibitor p27<sup>Kip1 </sup>is downregulated in a majority of human cancers due to ectopic proteolysis by the ubiquitin-proteasome pathway. The expression of p27 is subject to multiple mechanisms of control involving several transcription factors, kinase pathways and at least three different ubiquitin ligases (SCF<sup>SKP2</sup>, KPC, Pirh2), which regulate p27 transcription, translation, protein stability and subcellular localization. Using a chemical genetics approach, we have asked whether this control network can be modulated by small molecules such that p27 protein expression is restored in cancer cells.</p> <p>Results</p> <p>We developed a cell-based assay for measuring the levels of endogenous nuclear p27 in a high throughput screening format employing LNCaP prostate cancer cells engineered to overexpress SKP2. The assay platform was optimized to Z' factors of 0.48 - 0.6 and piloted by screening a total of 7368 chemical compounds. During the course of this work, we discovered two small molecules of previously unknown biological activity, SMIP001 and SMIP004, which increase the nuclear level of p27 at low micromolar concentrations. SMIPs (small molecule inhibitors of p27 depletion) also upregulate p21<sup>Cip1</sup>, inhibit cellular CDK2 activity, induce G1 delay, inhibit colony formation in soft agar and exhibit preferential cytotoxicity in LNCaP cells relative to normal human fibroblasts. Unlike SMIP001, SMIP004 was found to downregulate SKP2 and to stabilize p27, although neither SMIP is a proteasome inhibitor. Whereas the screening endpoint - nuclear p27 - was robustly modulated by the compounds, SMIP-mediated cell cycle arrest and apoptosis were not strictly dependent on p27 and p21 - a finding that is explained by parallel inhibitory effects of SMIPs on positive cell cycle regulators, including cyclins E and A, and CDK4.</p> <p>Conclusions</p> <p>Our data provide proof-of-principle that the screening platform we developed, using endogenous nuclear p27 as an endpoint, presents an effective means of identifying bioactive molecules with cancer selective antiproliferative activity. This approach, when applied to larger and more diverse sets of compounds with refined drug-like properties, bears the potential of revealing both unknown cellular pathways globally impinging on p27 and novel leads for chemotherapeutics targeting a prominent molecular defect of human cancers.</p

    What we learn about bipolar disorder from large-scale neuroimaging:Findings and future directions from the ENIGMA Bipolar Disorder Working Group

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    MRI-derived brain measures offer a link between genes, the environment and behavior and have been widely studied in bipolar disorder (BD). However, many neuroimaging studies of BD have been underpowered, leading to varied results and uncertainty regarding effects. The Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) Bipolar Disorder Working Group was formed in 2012 to empower discoveries, generate consensus findings and inform future hypothesis-driven studies of BD. Through this effort, over 150 researchers from 20 countries and 55 institutions pool data and resources to produce the largest neuroimaging studies of BD ever conducted. The ENIGMA Bipolar Disorder Working Group applies standardized processing and analysis techniques to empower large-scale meta- and mega-analyses of multimodal brain MRI and improve the replicability of studies relating brain variation to clinical and genetic data. Initial BD Working Group studies reveal widespread patterns of lower cortical thickness, subcortical volume and disrupted white matter integrity associated with BD. Findings also include mapping brain alterations of common medications like lithium, symptom patterns and clinical risk profiles and have provided further insights into the pathophysiological mechanisms of BD. Here we discuss key findings from the BD working group, its ongoing projects and future directions for large-scale, collaborative studies of mental illness
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