1,027 research outputs found

    Cytoprotective and antioxidant effects of the methanol extract of Eremomastax Speciosa in rats

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    Background: Ethno-botanical information shows that Eremomastax speciosa is used in the traditional management of various stomach complaints including gastro-duodenal ulcers.Materials and Methods: In this study, we tested the cytoprotective potential of the whole plant methanol extract (100-200 mg/kg, p.o), against HCl/ethanol, absolute ethanol, cold/restraint stress rats, and pylorus legated rats pre-treated with indomethacin. The effects of the extract on gastric lesion inhibition, the volume of gastric juice, gastric pH, gastric acid output, mucus production and gastric peptic activity were recorded. Oxidative stress parameters were measured in blood and gastric tissue samples obtained from the animals in all the models tested.Results: The extract significantly (p<0.05), reduced the formation of cold/restraint ulcers by (31-60%, inhibition), completely inhibited (100%) the formation of lesions induced by HCl/ethanol at the highest dose, but was less effective against absolute ethanol (22-46% inhibition). The extract (200 mg/kg), significantly reduced lesion formation (P<0.01), gastric acidity (P<0.01), and volume of gastric secretions (P<0.05), in the indomethacin/pylorus ligation model, and did not affect the activity of pepsin in gastric juice. Blood concentrations of antioxidant enzymes (catalase, SOD and GSH), increased significantly and MDA concentrations decreased in all models tested.Conclusion: Cytoprotection by E. speciosa methanol extract was attributed to its ability to reduce acid secretion, and to enhance mucosal defence and in vivo antioxidant status.Key words: Eremomastax speciosa, cytoprotection, gastric ulcers, antioxidant statu

    Site-specific incorporation of phosphotyrosine using an expanded genetic code.

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    Access to phosphoproteins with stoichiometric and site-specific phosphorylation status is key to understanding the role of protein phosphorylation. Here we report an efficient method to generate pure, active phosphotyrosine-containing proteins by genetically encoding a stable phosphotyrosine analog that is convertible to native phosphotyrosine. We demonstrate its general compatibility with proteins of various sizes, phosphotyrosine sites and functions, and reveal a possible role of tyrosine phosphorylation in negative regulation of ubiquitination

    A novel Family Dignity Intervention (FDI) for enhancing and informing holistic palliative care in Asia: study protocol for a randomized controlled trial

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    Background The lack of a holistic approach to palliative care can lead to a fractured sense of dignity at the end of life, resulting in depression, hopelessness, feelings of being a burden to others, and the loss of the will to live among terminally ill patients. Building on the clinical foundation of Dignity Therapy, together with the empirical understanding of dignity-related concerns of Asian families facing terminal illness, a novel Family Dignity Intervention (FDI) has been developed for Asian palliative care. FDI comprises a recorded interview with a patient and their primary family caregiver, which is transcribed, edited into a legacy document, and returned to the dyads for sharing with the rest of the patient’s family. The aims of this study are to assess the feasibility, acceptability and potential effectiveness of FDI in reducing psychosocial, emotional, spiritual, and psychophysiological distress in community-dwelling and in-patient, Asian, older terminally ill patients and their families living in Singapore. Methods/design An open-label randomized controlled trial. One hundred and twenty-six patient-family dyads are randomly allocated to one of two groups: (1) an intervention group (FDI offered in addition to standard psychological care) and (2) a control group (standard psychological care). Both quantitative and qualitative outcomes are assessed in face-to-face interviews at baseline, 3 days and 2 weeks after intervention, as well as during an exit interview with family caregivers at 2 months post bereavement. Primary outcome measures include sense of dignity for patients and psychological distress for caregivers. Secondary outcomes include meaning in life, quality of life, spirituality, hopefulness, perceived support, and psychophysiological wellbeing, as well as bereavement outcomes for caregivers. Qualitative data are analyzed using the Framework method. Discussion To date, there is no available palliative care intervention for dignity enhancement in Asia. This first-of-its-kind study develops and tests an evidence-based, family driven, psycho-socio-spiritual intervention for enhancing dignity and wellbeing among Asian patients and families facing mortality. It addresses a critical gap in the provision of holistic palliative care. The expected outcomes will contribute to advancements in both theories and practices of palliative care for Singapore and its neighboring regions while serving to inform similar developments in other Asian communities. Trial registration ClinicalTrials.gov, ID: NCT03200730. Registered on 26 June 2017

    In situ interface engineering for probing the limit of quantum dot photovoltaic devices.

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    Quantum dot (QD) photovoltaic devices are attractive for their low-cost synthesis, tunable band gap and potentially high power conversion efficiency (PCE). However, the experimentally achieved efficiency to date remains far from ideal. Here, we report an in-situ fabrication and investigation of single TiO2-nanowire/CdSe-QD heterojunction solar cell (QDHSC) using a custom-designed photoelectric transmission electron microscope (TEM) holder. A mobile counter electrode is used to precisely tune the interface area for in situ photoelectrical measurements, which reveals a strong interface area dependent PCE. Theoretical simulations show that the simplified single nanowire solar cell structure can minimize the interface area and associated charge scattering to enable an efficient charge collection. Additionally, the optical antenna effect of nanowire-based QDHSCs can further enhance the absorption and boost the PCE. This study establishes a robust 'nanolab' platform in a TEM for in situ photoelectrical studies and provides valuable insight into the interfacial effects in nanoscale solar cells

    Architecture of Pol II(G) and molecular mechanism of transcription regulation by Gdown1.

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    Tight binding of Gdown1 represses RNA polymerase II (Pol II) function in a manner that is reversed by Mediator, but the structural basis of these processes is unclear. Although Gdown1 is intrinsically disordered, its Pol II interacting domains were localized and shown to occlude transcription factor IIF (TFIIF) and transcription factor IIB (TFIIB) binding by perfect positioning on their Pol II interaction sites. Robust binding of Gdown1 to Pol II is established by cooperative interactions of a strong Pol II binding region and two weaker binding modulatory regions, thus providing a mechanism both for tight Pol II binding and transcription inhibition and for its reversal. In support of a physiological function for Gdown1 in transcription repression, Gdown1 co-localizes with Pol II in transcriptionally silent nuclei of early Drosophila embryos but re-localizes to the cytoplasm during zygotic genome activation. Our study reveals a self-inactivation through Gdown1 binding as a unique mode of repression in Pol II function

    Pandemic Drugs at Pandemic Speed: Infrastructure for Accelerating COVID-19 Drug Discovery with Hybrid Machine Learning- and Physics-based Simulations on High Performance Computers

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    The race to meet the challenges of the global pandemic has served as a reminder that the existing drug discovery process is expensive, inefficient and slow. There is a major bottleneck screening the vast number of potential small molecules to shortlist lead compounds for antiviral drug development. New opportunities to accelerate drug discovery lie at the interface between machine learning methods, in this case, developed for linear accelerators, and physics-based methods. The two in silico methods, each have their own advantages and limitations which, interestingly, complement each other. Here, we present an innovative infrastructural development that combines both approaches to accelerate drug discovery. The scale of the potential resulting workflow is such that it is dependent on supercomputing to achieve extremely high throughput. We have demonstrated the viability of this workflow for the study of inhibitors for four COVID-19 target proteins and our ability to perform the required large-scale calculations to identify lead antiviral compounds through repurposing on a variety of supercomputers

    Momordica charantia (bitter melon) inhibits primary human adipocyte differentiation by modulating adipogenic genes

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    <p>Abstract</p> <p>Background</p> <p>Escalating trends of obesity and associated type 2 diabetes (T2D) has prompted an increase in the use of alternative and complementary functional foods. <it>Momordica charantia </it>or bitter melon (BM) that is traditionally used to treat diabetes and complications has been demonstrated to alleviate hyperglycemia as well as reduce adiposity in rodents. However, its effects on human adipocytes remain unknown. The objective of our study was to investigate the effects of BM juice (BMJ) on lipid accumulation and adipocyte differentiation transcription factors in primary human differentiating preadipocytes and adipocytes.</p> <p>Methods</p> <p>Commercially available cryopreserved primary human preadipocytes were treated with and without BMJ during and after differentiation. Cytotoxicity, lipid accumulation, and adipogenic genes mRNA expression was measured by commercial enzymatic assay kits and semi-quantitative RT-PCR (RT-PCR).</p> <p>Results</p> <p>Preadipocytes treated with varying concentrations of BMJ during differentiation demonstrated significant reduction in lipid content with a concomitant reduction in mRNA expression of adipocyte transcription factors such as, peroxisome proliferator-associated receptor γ (PPARγ) and sterol regulatory element-binding protein 1c (SREBP-1c) and adipocytokine, resistin. Similarly, adipocytes treated with BMJ for 48 h demonstrated reduced lipid content, perilipin mRNA expression, and increased lipolysis as measured by the release of glycerol.</p> <p>Conclusion</p> <p>Our data suggests that BMJ is a potent inhibitor of lipogenesis and stimulator of lipolysis activity in human adipocytes. BMJ may therefore prove to be an effective complementary or alternative therapy to reduce adipogenesis in humans.</p
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