67 research outputs found

    Bioavailability of the Antimalarial Drug Artemisinin Delivered Orally as Dried Leaves of Artemisia annua: the Role of Solubility and Protein.

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    Malaria treatment using orally consumed dried leaves of the artemisinin producing GRAS plant Artemisia annua has recently shown promise. Previously we showed, oral consumption of A. annua dried leaves (DLA) yielded \u3e40 times more artemisinin in the blood of mice than treatment with pure artemisinin. Using the Caco-2 cell culture model of the human intestinal epithelium, we also showed that compared to pure artemisinin, digested DLA doubled the permeability (Papp). Here, using simulated human digestion, we show that artemisinin solubility is about seven times higher in digestates of DLA than in digestates of pure artemisinin, likely contributing to its enhanced bioavailability. Digestion with pure artemisinin combined with levels of essential oils comparable to that in DLA increased the solubility of artemisinin 2.5 times indicating essential oils play a role in increasing artemisinin solubility. Interestingly, increasing the starting concentration of artemisinin in Caco-2 transport studies did not alter Papp. Considering malaria affects mostly young children and about 60% of the population experiences DLA as unpleasant tasting, we also tested several protein rich foods as potential flavor-masking agents for their effects on bioavailability. We showed that while taste was masked, peanuts and a peanut-based paste used to treat malnutrition, PlumpyNut, reduced artemisinin and flavonoid levels in simulated digestates, respectively, likely decreasing their bioavailability. Experiments to further investigate the role of several compounds such as camphor, a principle component of the essential oil fraction, and flavonoids on artemisinin solubility and bioavailability are ongoing. The results of these experiments are helping to explain the increased bioavailability afforded by DLA seen in mice

    Multi texture analysis of colorectal cancer continuum using multispectral imagery

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    Purpose This paper proposes to characterize the continuum of colorectal cancer (CRC) using multiple texture features extracted from multispectral optical microscopy images. Three types of pathological tissues (PT) are considered: benign hyperplasia, intraepithelial neoplasia and carcinoma. Materials and Methods In the proposed approach, the region of interest containing PT is first extracted from multispectral images using active contour segmentation. This region is then encoded using texture features based on the Laplacian-of-Gaussian (LoG) filter, discrete wavelets (DW) and gray level co-occurrence matrices (GLCM). To assess the significance of textural differences between PT types, a statistical analysis based on the Kruskal-Wallis test is performed. The usefulness of texture features is then evaluated quantitatively in terms of their ability to predict PT types using various classifier models. Results Preliminary results show significant texture differences between PT types, for all texture features (p-value < 0.01). Individually, GLCM texture features outperform LoG and DW features in terms of PT type prediction. However, a higher performance can be achieved by combining all texture features, resulting in a mean classification accuracy of 98.92%, sensitivity of 98.12%, and specificity of 99.67%. Conclusions These results demonstrate the efficiency and effectiveness of combining multiple texture features for characterizing the continuum of CRC and discriminating between pathological tissues in multispectral images

    Oceans and human health : navigating changes on Canada’s coasts

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    Ocean conditions can affect human health in a variety of ways that are often overlooked and unappreciated. Oceans adjacent to Canada are affected by many anthropogenic stressors, with implications for human health and well-being. Climate change further escalates these pressures and can expose coastal populations to unique health hazards and distressing conditions. However, current research efforts, education or training curriculums, and policies in Canada critically lack explicit consideration of these ocean–public health linkages. The objective of this paper is to present multiple disciplinary perspectives from academics and health practitioners to inform the development of future directions for research, capacity development, and policy and practice at the interface of oceans and human health in Canada. We synthesize major ocean and human health linkages in Canada, and identify climate-sensitive drivers of change, drawing attention to unique considerations in Canada. To support effective, sustained, and equitable collaborations at the nexus of oceans and human health, we recommend the need for progress in three critical areas: (i) holistic worldviews and perspectives, (ii) capacity development, and (iii) structural supports. Canada can play a key role in supporting the global community in addressing the health challenges of climate and ocean changes

    County and Demographic Differences in Drug Arrests and Controlled Substance Use in Maine

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    . Introduction: The Diversion Alert Program (DAP) was established to curb misuse of drugs and help identify people who may need treatment for substance use disorder (SUD). Law enforcement compiled arrest data into a database accessible by health care providers. Our objectives were to identify regional and demographic differences in drug use and misuse in Maine. Methods: All arrests (N = 11 234) reported to the DAP from 2013 to 2018 were examined by county and arrestee demographics, and classified into families (opioids, stimulants, sedatives). The Drug Enforcement Administration’s Automation of Reports and Consolidated Orders System (ARCOS) tracks the distribution of controlled pharmaceuticals (Schedule II-III). Opioids were converted to oral morphine milligram equivalents (MMEs). County and zip-code maps were constructed. Results: The most arrests per capita occurred in Androscoggin, Knox, and Cumberland Counties. Opioids were the most common drug class in arrests in all counties except Aroostook County, where stimulants were most common. Medical distribution of opioids varied. Although buprenorphine doubled, many prescription opioids (eg, hydrocodone, fentanyl, oxymorphone) exhibited large (\u3e 50%) reductions in distribution. Methadone was the predominant opioid statewide (56.4% of total MMEs), although there were sizable differences between regions (Presque Isle = 8.6%, Bangor = 78.9%). Amphetamine distribution increased by 67.9%. Discussion: The DAP, a unique pharmacoepidemiological resource, revealed a 6-fold difference in drug arrests by county. Regional differences in methadone may be due to heterogeneities in methadone clinic distribution. Conclusions: The decrease in most prescription opioids, but increase in prescription stimulants, may warrant continued monitoring to improve public health

    SIV Nef Proteins Recruit the AP-2 Complex to Antagonize Tetherin and Facilitate Virion Release

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    Lentiviral Nef proteins have multiple functions and are important for viral pathogenesis. Recently, Nef proteins from many simian immunodefiency viruses were shown to antagonize a cellular antiviral protein, named Tetherin, that blocks release of viral particles from the cell surface. However, the mechanism by which Nef antagonizes Tetherin is unknown. Here, using related Nef proteins that differ in their ability to antagonize Tetherin, we identify three amino-acids in the C-terminal domain of Nef that are critical specifically for its ability to antagonize Tetherin. Additionally, divergent Nef proteins bind to the AP-2 clathrin adaptor complex, and we show that residues important for this interaction are required for Tetherin antagonism, downregulation of Tetherin from the cell surface and removal of Tetherin from sites of particle assembly. Accordingly, depletion of AP-2 using RNA interference impairs the ability of Nef to antagonize Tetherin, demonstrating that AP-2 recruitment is required for Nef proteins to counteract this antiviral protein

    LabKey Server: An open source platform for scientific data integration, analysis and collaboration

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    <p>Abstract</p> <p>Background</p> <p>Broad-based collaborations are becoming increasingly common among disease researchers. For example, the Global HIV Enterprise has united cross-disciplinary consortia to speed progress towards HIV vaccines through coordinated research across the boundaries of institutions, continents and specialties. New, end-to-end software tools for data and specimen management are necessary to achieve the ambitious goals of such alliances. These tools must enable researchers to organize and integrate heterogeneous data early in the discovery process, standardize processes, gain new insights into pooled data and collaborate securely.</p> <p>Results</p> <p>To meet these needs, we enhanced the LabKey Server platform, formerly known as CPAS. This freely available, open source software is maintained by professional engineers who use commercially proven practices for software development and maintenance. Recent enhancements support: (i) Submitting specimens requests across collaborating organizations (ii) Graphically defining new experimental data types, metadata and wizards for data collection (iii) Transitioning experimental results from a multiplicity of spreadsheets to custom tables in a shared database (iv) Securely organizing, integrating, analyzing, visualizing and sharing diverse data types, from clinical records to specimens to complex assays (v) Interacting dynamically with external data sources (vi) Tracking study participants and cohorts over time (vii) Developing custom interfaces using client libraries (viii) Authoring custom visualizations in a built-in R scripting environment.</p> <p>Diverse research organizations have adopted and adapted LabKey Server, including consortia within the Global HIV Enterprise. Atlas is an installation of LabKey Server that has been tailored to serve these consortia. It is in production use and demonstrates the core capabilities of LabKey Server. Atlas now has over 2,800 active user accounts originating from approximately 36 countries and 350 organizations. It tracks roughly 27,000 assay runs, 860,000 specimen vials and 1,300,000 vial transfers.</p> <p>Conclusions</p> <p>Sharing data, analysis tools and infrastructure can speed the efforts of large research consortia by enhancing efficiency and enabling new insights. The Atlas installation of LabKey Server demonstrates the utility of the LabKey platform for collaborative research. Stable, supported builds of LabKey Server are freely available for download at <url>http://www.labkey.org</url>. Documentation and source code are available under the Apache License 2.0.</p

    Role of CCL3L1-CCR5 Genotypes in the Epidemic Spread of HIV-1 and Evaluation of Vaccine Efficacy

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    Polymorphisms in CCR5, the major coreceptor for HIV, and CCL3L1, a potent CCR5 ligand and HIV-suppressive chemokine, are determinants of HIV-AIDS susceptibility. Here, we mathematically modeled the potential impact of these genetic factors on the epidemic spread of HIV, as well as on its prevention.Ro, the basic reproductive number, is a fundamental concept in explaining the emergence and persistence of epidemics. By modeling sexual transmission among HIV+/HIV- partner pairs, we find that Ro estimates, and concordantly, the temporal and spatial patterns of HIV outgrowth are highly dependent on the infecting partners' CCL3L1-CCR5 genotype. Ro was least and highest when the infected partner possessed protective and detrimental CCL3L1-CCR5 genotypes, respectively. The modeling data indicate that in populations such as Pygmies with a high CCL3L1 gene dose and protective CCR5 genotypes, the spread of HIV might be minimal. Additionally, Pc, the critical vaccination proportion, an estimate of the fraction of the population that must be vaccinated successfully to eradicate an epidemic was <1 only when the infected partner had a protective CCL3L1-CCR5 genotype. Since in practice Pc cannot be >1, to prevent epidemic spread, population groups defined by specific CCL3L1-CCR5 genotypes might require repeated vaccination, or as our models suggest, a vaccine with an efficacy of >70%. Further, failure to account for CCL3L1-CCR5-based genetic risk might confound estimates of vaccine efficacy. For example, in a modeled trial of 500 subjects, misallocation of CCL3L1-CCR5 genotype of only 25 (5%) subjects between placebo and vaccine arms results in a relative error of approximately 12% from the true vaccine efficacy.CCL3L1-CCR5 genotypes may impact on the dynamics of the HIV epidemic and, consequently, the observed heterogeneous global distribution of HIV infection. As Ro is lowest when the infecting partner has beneficial CCL3L1-CCR5 genotypes, we infer that therapeutic vaccines directed towards reducing the infectivity of the host may play a role in halting epidemic spread. Further, CCL3L1-CCR5 genotype may provide critical guidance for optimizing the design and evaluation of HIV-1 vaccine trials and prevention programs

    The First Post-Kepler Brightness Dips of KIC 8462852

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    We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <<1um, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process
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