227 research outputs found

    Vascular disrupting agent for neovascular age related macular degeneration: a pilot study of the safety and efficacy of intravenous combretastatin A-4 phosphate

    Get PDF
    BACKGROUND: This study was designed to assess the safety, tolerability, and efficacy of intravenous infusion of CA4P in patients with neovascular age-related macular degeneration (AMD). METHODS: Prospective, interventional, dose-escalation clinical trial. Eight patients with neovascular AMD refractory to at least 2 sessions of photodynamic therapy received CA4P at a dose of 27 or 36 mg/m2 as weekly intravenous infusion for 4 consecutive weeks. Safety was monitored by vital signs, ocular and physical examinations, electrocardiogram, routine laboratory tests, and collection of adverse events. Efficacy was assessed using retinal fluorescein angiography, optical coherence tomography, and best corrected visual acuity (BCVA). RESULTS: The most common adverse events were elevated blood pressure (46.7%), QTc prolongation (23.3%), elevated temperature (13.3%), and headache (10%), followed by nausea and eye injection (6.7%). There were no adverse events that were considered severe in intensity and none resulted in discontinuation of treatment. There was reduction of the excess foveal thickness by 24.15% at end of treatment period and by 43.75% at end of the two-month follow-up (p = 0.674 and 0.161, respectively). BCVA remained stable throughout the treatment and follow-up periods. CONCLUSIONS: The safety profile of intravenous CA4P was consistent with that reported in oncology trials of CA4P and with the class effects of vascular disruptive agents; however, the frequency of adverse events was different. There are evidences to suggest potential efficacy of CA4P in neovascular AMD. However, the level of systemic safety and efficacy indicates that systemic CA4P may not be suitable as an alternative monotherapy to current standard-of-care therapy

    Gamma (γ) tocopherol upregulates peroxisome proliferator activated receptor (PPAR) gamma (γ) expression in SW 480 human colon cancer cell lines

    Get PDF
    BACKGROUND: Tocopherols are lipid soluble antioxidants that exist as eight structurally different isoforms. The intake of γ-tocopherol is higher than α-tocopherol in the average US diet. The clinical results of the effects of vitamin E as a cancer preventive agent have been inconsistent. All published clinical trials with vitamin E have used α-tocopherol. Recent epidemiological, experimental and molecular studies suggest that γ-tocopherol may be a more potent chemopreventive form of vitamin E compared to the more-studied α-tocopherol. γ-Tocopherol exhibits differences in its ability to detoxify nitrogen dioxide, growth inhibitory effects on selected cancer cell lines, inhibition of neoplastic transformation in embryonic fibroblasts, and inhibition of cyclooxygenase-2 (COX-2) activity in macrophages and epithelial cells. Peroxisome proliferator activator receptor γ (PPARγ) is a promising molecular target for colon cancer prevention. Upregulation of PPARγ activity is anticarcinogenic through its effects on downstream genes that affect cellular proliferation and apoptosis. The thiazolidine class of drugs are powerful PPARγ ligands. Vitamin E has structural similarity to the thiazolidine, troglitazone. In this investigation, we tested the effects of both α and γ tocopherol on the expression of PPARγ mRNA and protein in SW 480 colon cancer cell lines. We also measured the intracellular concentrations of vitamin E in SW 480 colon cancer cell lines. RESULTS: We have discovered that the α and γ isoforms of vitamin E upregulate PPARγ mRNA and protein expression in the SW480 colon cancer cell lines. γ-Tocopherol is a better modulator of PPARγ expression than α-tocopherol at the concentrations tested. Intracellular concentrations increased as the vitamin E concentration added to the media was increased. Further, γ-tocopherol-treated cells have higher intracellular tocopherol concentrations than those treated with the same concentrations of α-tocopherol. CONCLUSION: Our data suggest that both α and γ tocopherol can upregulate the expression of PPARγ which is considered an important molecular target for colon cancer chemoprevention. We show that the expression of PPARγ mRNA and protein are increased and these effects are more pronounced with γ-tocopherol. γ-Tocopherol's ability to upregulate PPARγ expression and achieve higher intracellular concentrations in the colonic tissue may be relevant to colon cancer prevention. We also show that the intracellular concentrations of γ-tocopherol are several fold higher than α-tocopherol. Further work on other colon cancer cell lines are required to quantitate differences in the ability of these forms of vitamin E to induce apoptosis, suppress cell proliferation and act as PPAR ligands as well as determine their effects in conjunction with other chemopreventive agents. Upregulation of PPARγ by the tocopherols and in particular by γ-tocopherol may have relevance not only to cancer prevention but also to the management of inflammatory and cardiovascular disorders

    Y2Y4 Receptor Double Knockout Protects Against Obesity Due to a High-Fat Diet or Y1 Receptor Deficiency in Mice

    Get PDF
    Neuropeptide Y receptors are critical regulators of energy homeostasis, but the functional interactions and relative contributions of Y receptors and the environment in this process are unknown. We measured the effects of an ad libitum diet of normal or high-fat food on energy balance in mice with single, double, or triple deficiencies of Y1, Y2, or Y4 receptors. Whereas wild-type mice developed diet-induced obesity, Y2Y4 double knockouts did not. In contrast, Y1 knockout or Y1Y2 or Y1Y4 receptor double knockout mice developed an exacerbated diet-induced obesity syndrome. Remarkably, the antiobesity effect of Y2Y4 deficiency was stronger than the obesogenic effect of Y1 deficiency, since Y1Y2Y4 triple knockouts did not develop obesity on the high-fat diet. Resistance to diet-induced obesity in Y2Y4 knockouts was associated with reduced food intake and improved glucose tolerance in the absence of changes in total physical activity. Fecal concentration of free fatty acids was significantly increased in Y2Y4 knockouts in association with a significantly reduced bile acid pool and marked alterations in intestinal morphology. In addition, hypothalamic proopiomelanocortin expression was decreased in diet-induced obesity (in both wild-type and Y1 receptor knockout mice) but not in obesity-resistant Y2Y4 receptor knockout mice fed a high-fat diet. Therefore, deletion of Y2 and Y4 receptors synergistically protects against diet-induced obesity, at least partially via changes in food intake and hypothalamic proopiomelanocortin expression

    Plasma carotenoids, retinol, and tocopherols and postmenopausal breast cancer risk in the Multiethnic Cohort Study: a nested case-control study

    Get PDF
    Assessments by the handful of prospective studies of the association of serum antioxidants and breast cancer risk have yielded inconsistent results. This multiethnic nested case-control study sought to examine the association of plasma carotenoids, retinol, and tocopherols with postmenopausal breast cancer risk.From the biospecimen subcohort of the Multiethnic Cohort Study, 286 incident postmenopausal breast cancer cases were matched to 535 controls on age, sex, ethnicity, study location (Hawaii or California), smoking status, date/time of collection and hours of fasting. We measured prediagnostic circulating levels of individual carotenoids, retinol, and tocopherols. Conditional logistic regression was used to compute odds ratios and 95% confidence intervals.Women with breast cancer tended to have lower levels of plasma carotenoids and tocopherols than matched controls, but the differences were not large or statistically significant and the trends were not monotonic. No association was seen with retinol. A sensitivity analysis excluding cases diagnosed within 1 year after blood draw did not alter the findings.The lack of significant associations in this multiethnic population is consistent with previously observed results from less racially-diverse cohorts and serves as further evidence against a causal link between plasma micronutrient concentrations and postmenopausal breast cancer risk

    The Changing Face of Neolithic and Bronze Age Ireland: A Big Data Approach to the Settlement and Burial Records

    Get PDF
    This paper synthesizes and analyses the spatial and temporal patterns of archaeological sites in Ireland spanning the Neolithic period and the Bronze Age transition (4300-1900 cal BC). Included are a large number of unpublished, newly discovered sites excavated through development-led projects. Data were also sourced from national archives, published excavation reports and on-line databases. Software tools were developed to deal with the varying nature and resolution of these datasets, allowing chronology to be considered in the analysis to a degree that is usually not possible in prehistoric studies. Summed radiocarbon probabilities are used to examine the dataset using context- and sample-sensitive approaches. Visualisations of spatial and chronological data illustrate the expansion of Early Neolithic settlement, followed by an apparent attenuation of all settlement activity. The Late Neolithic and Chalcolithic periods are characterised by a resurgence and diversification of activity. To assess the significance of these observations, Irish radiocarbon data are compared to an idealized model derived from North American data. Even after taking various considerations into account, human population increases can be suggested to have occurred during the Early and Late Neolithic periods. Gaps and biases in the data are discussed and priorities for future work are identified

    The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer

    Get PDF
    Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al

    Randomised phase II study of ASA404 combined with carboplatin and paclitaxel in previously untreated advanced non-small cell lung cancer

    Get PDF
    ASA404 (5,6-dimethylxanthenone-4-acetic acid or DMXAA) is a small-molecule tumour-vascular disrupting agent (Tumour-VDA). This randomised phase II study evaluated ASA404 plus standard therapy of carboplatin and paclitaxel in patients with histologically confirmed stage IIIb or IV non-small cell lung cancer (NSCLC) not previously treated with chemotherapy. Patients were randomised to receive ⩽6 cycles of carboplatin area under the plasma concentration–time curve 6 mg ml−1 min and paclitaxel 175 mg m−2 (CP, n=36) or standard therapy plus ASA404 1200 mg m−2 (ASA404-CP, n=37). There was little change in the systemic exposure of either total or free carboplatin or paclitaxel on addition of ASA404. Safety profiles were similar and manageable in both groups, with most adverse effects attributed to standard therapy. Tumour response rate (31 vs 22%), median time to tumour progression (5.4 vs 4.4 months) and median survival (14.0 vs 8.8 months, hazard ratio 0.73, 95% CI 0.39, 1.38) were improved in the ASA404 combination group compared with the standard therapy group. In conclusion, this study establishes the feasibility of combining ASA404 with carboplatin and paclitaxel in patients with previously untreated, advanced NSCLC, demonstrating a manageable safety profile and lack of adverse pharmacokinetic interactions. The results indicate that there may be a benefit associated with ASA404, but this needs to be evaluated in a larger trial
    corecore