69 research outputs found

    Anticancer activity of a sub-fraction of dichloromethane extract of Strobilanthes crispus on human breast and prostate cancer cells in vitro

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    <p>Abstract</p> <p>Background</p> <p>The leaves of <it>Strobilanthes crispus </it>(<it>S. crispus</it>) which is native to the regions of Madagascar to the Malay Archipelago, are used in folk medicine for their antidiabetic, diuretic, anticancer and blood pressure lowering properties. Crude extracts of this plant have been found to be cytotoxic to human cancer cell lines and protective against chemically-induced hepatocarcinogenesis in rats. In this study, the cytotoxicity of various sub-fractions of dichloromethane extract isolated from the leaves of <it>S. crispus </it>was determined and the anticancer activity of one of the bioactive sub-fractions, SC/D-F9, was further analysed in breast and prostate cancer cell lines.</p> <p>Methods</p> <p>The dichloromethane extract of <it>S. crispus </it>was chromatographed on silica gel by flash column chromatography. The ability of the various sub-fractions obtained to induce cell death of MCF-7, MDA-MB-231, PC-3 and DU-145 cell lines was determined using the LDH assay. The dose-response effect and the EC<sub>50 </sub>values of the active sub-fraction, SC/D-F9, were determined. Apoptosis was detected using Annexin V antibody and propidium iodide staining and analysed by fluorescence microscopy and flow cytometry, while caspase 3/7 activity was detected using FLICA caspase inhibitor and analysed by fluorescence microscopy.</p> <p>Results</p> <p>Selected sub-fractions of the dichloromethane extract induced death of MCF-7, MDA-MB-231, PC-3 and DU-145 cells. The sub-fraction SC/D-F9, consistently killed breast and prostate cancer cell lines with low EC<sub>50 </sub>values but is non-cytotoxic to the normal breast epithelial cell line, MCF-10A. SC/D-F9 displayed relatively higher cytotoxicity compared to tamoxifen, paclitaxel, docetaxel and doxorubicin. Cell death induced by SC/D-F9 occurred via apoptosis with the involvement of caspase 3 and/or 7.</p> <p>Conclusions</p> <p>A dichloromethane sub-fraction of <it>S. crispus </it>displayed potent anticancer activities <it>in vitro </it>that can be further exploited for the development of a potential therapeutic anticancer agent.</p

    An Antiretroviral/Zinc Combination Gel Provides 24 Hours of Complete Protection against Vaginal SHIV Infection in Macaques

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    Repeated use, coitus-independent microbicide gels that do not contain antiretroviral agents also used as first line HIV therapy are urgently needed to curb HIV spread. Current formulations require high doses (millimolar range) of antiretroviral drugs and typically only provide short-term protection in macaques. We used the macaque model to test the efficacy of a novel combination microbicide gel containing zinc acetate and micromolar doses of the novel non-nucleoside reverse transcriptase inhibitor MIV-150 for up to 24 h after repeated gel application.Rhesus macaques were vaginally challenged with SHIV-RT up to 24 h after repeated administration of microbicide versus placebo gels. Infection status was determined by measuring virologic and immunologic parameters. Combination microbicide gels containing 14 mM zinc acetate dihydrate and 50 µM MIV-150 afforded full protection (21 of 21 animals) for up to 24 h after 2 weeks of daily application. Partial protection was achieved with the MIV-150 gel (56% of control at 8 h after last application, 11% at 24 h), while the zinc acetate gel afforded more pronounced protection (67% at 8-24 h). Marked protection persisted when the zinc acetate or MIV-150/zinc acetate gels were applied every other day for 4 weeks prior to challenge 24 h after the last gel was administered (11 of 14 protected). More MIV-150 was associated with cervical tissue 8 h after daily dosing of MIV-150/zinc acetate versus MIV-150, while comparable MIV-150 levels were associated with vaginal tissues and at 24 h.A combination MIV-150/zinc acetate gel and a zinc acetate gel provide significant protection against SHIV-RT infection for up to 24 h. This represents a novel advancement, identifying microbicides that do not contain anti-viral agents used to treat HIV infection and which can be used repeatedly and independently of coitus, and underscores the need for future clinical testing of their safety and ability to prevent HIV transmission in humans

    Reporting and the Transformations of the Journalistic Field: US news media, 1890-2000

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    How have journalistic ideals of public service arisen? To what extent do journalists live up to these ideals? Can we make any claims as to the social conditions that this performance depends on? Using Bourdieu’s theory of fields of cultural production, this article addresses these questions with evidence from the history of journalism in the United States. What is most distinctive about modern journalism is a specific practice: active news-gathering or reporting. This practice became common in the 1860s and 1870s with the emergence of journalism as a field with its own stakes, relatively independent from political advantage or literary merit. The power of field-specific capital to organize practices in the media has varied since then. The field consolidated in the era from 1890 to 1914, with the newspaper industry expanding. In the interwar years, the boundary between PR and journalism became blurry and the institutional basis for active news-gathering declined. Under favorable economic and political conditions reporting practices, including local and investigative reporting, flourished between 1945 and1970 across media forms. In the past 40 years the importance of active news-gathering has declined

    Public Service Broadcasting-Friends Groups as a Microcosm of Public Interest Media Advocacy

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    This article is concerned with the interdependencies between public service broadcasters and the third sector, an area in which there is little research that has provided in-depth analysis of case studies. It investigates and compares three public service broadcasting (PSB)-Friends groups in the UK, Australia, and South Africa. By means of analyzing semi-structured interviews and archival data, we address development, institutionalization and policy impact of the Voice of the Listener &amp; Viewer, ABC-Friends, and SOS Coalition. Drawing on resource-mobilization theory we argue that, in particular, material, human, and informational resources, contextualized with political opportunities, have analytic value in explaining similarities and differences between the groups, which are conceived as a microcosm of public interest media advocacy
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