5,829 research outputs found

    PIP2 Activates TRPV5 and Releases Its Inhibition by Intracellular Mg2+

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    The transient receptor potential type V5 channel (TRPV5) is a Ca2+-selective TRP channel important for epithelial Ca2+ transport. Intracellular Mg2+ causes a fast voltage-dependent block of the TRPV5 channel by binding to the selectivity filter. Here, we report that intracellular Mg2+ binding to the selectivity filter of TRPV5 also causes a slower reversible conformational change leading to channel closure. We further report that PIP2 activates TRPV5. Activation of TRPV5 by PIP2 is independent of Mg2+. Yet, PIP2 decreases sensitivity of the channel to the Mg2+-induced slow inhibition. Mutation of aspartate-542, a critical Mg2+-binding site in the selectivity filter, abolishes Mg2+-induced slow inhibition. PIP2 has no effects on Mg2+-induced voltage-dependent block. Thus, PIP2 prevents the Mg2+-induced conformational change without affecting Mg2+ binding to the selectivity filter. Hydrolysis of PIP2 via receptor activation of phospholipase C sensitizes TRPV5 to the Mg2+-induced slow inhibition. These results provide a novel mechanism for regulation of TRP channels by phospholipase C–activating hormones via alteration of the sensitivity to intracellular Mg2+

    Utilization of Western Medicine and Traditional Chinese Medicine Services by Physicians and Their Relatives: The Role of Training Background

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    Despite extensive efforts to improve the attitude and practice of physicians with respect to complementary and alternative medicine (CAM), the role of training background on physician's own utilization of mainstream Western medicine (WM) and CAM remains unclear. We aimed to compare personal utilizations of WM and traditional Chinese medicine (TCM) among doctors trained in WM only, TCM only or both. A retrospective population-based study was conducted using the 2004 Taiwan's National Health Insurance data. A total of 103 879 doctors and their relatives and 2 623 658 other adults with equivalent socioeconomic status were analyzed. Ambulatory care utilization of WM and TCM services was compared using the following three measures: probability of any use, number of visits and total annual expenditure. Doctors who were trained in Western medicine only (WMDs) had the highest WM use, followed by doctors who were trained in both (WMD-CMDs), while Chinese medicine-trained doctors (CMDs) had the lowest use. For TCM use, a reverse pattern was observed. Similar patterns were found among doctors' relatives. Compared with other adults with equivalent socioeconomic status, both the CMDs and WMD-CMDs had a greater use of TCM services. For WM, although the WMDs' probability and frequency of usage were similar to other adults, they incurred considerably higher expenditure. The use of WM and TCM by doctors and their relatives was significantly associated with the training background of the doctors. This highlights the importance of how increasing knowledge and understanding of other medical discipline may influence a practitioner's care-providing behaviors

    Survival analysis of Stage IIA1 and IIA2 cervical cancer patients

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    AbstractObjectiveThe aim of this study was to assess the benefits of the 2009 International Federation of Gynecology and Obstetrics (FIGO) staging system for survival of patients with Stage IIA1 and IIA2 cervical cancer (Cx Ca).Materials and MethodsA study cohort of 51 patients with Stage IIA Cx Ca was retrospectively collected from the 2004–2009 hospital-based, long-form Cx Ca data registry at Mackay Memorial Hospital (Taipei, Taiwan). The survivorship and overall survival were compared between these two groups (Stages IIA1 and IIA2) using log-rank test.ResultsThirty-six and 15 patients were classified into Stages IIA1 and IIA2, respectively. Stage IIA2 patients were younger than those with Stage IIA1 disease (mean age, 47.4 vs. 55.1 years, p = 0.008), but no significant difference was observed in confirmed pelvic lymph node status (21.4% vs. 38.5%, p = 0.280) between them. Although the 2-year and 5-year overall survival was better among Stage IIA1 patients, there was no significant difference in survival between Stage IIA1 and IIA2 groups (2-year, 90.6% vs. 77.8%; 5-year, 86.3% vs. 51.9%, p = 0.218).ConclusionAlthough there was a trend in survival difference between Stage IIA1 and IIA2 patients, the difference was not statistically significant. The revised FIGO 2009 staging system for Cx Ca defines a group of Stage IIA patients with bulky tumor (Stage IIA2) that are generally younger than Stage IIA1 patients. It is sensible to investigate an alternate or enhanced treatment scheme for Stage IIA2 patients. Ideally, the treatment scheme should prevent unnecessary radical surgery if a patient can be exposed to either chemotherapy or radiotherapy, alone or in combination

    miRTarBase update 2014: an information resource for experimentally validated miRNA-target interactions

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    MicroRNAs (miRNAs) are small non-coding RNA molecules capable of negatively regulating gene expression to control many cellular mechanisms. The miRTarBase database (http://mirtarbase.mbc.nctu.edu.tw/) provides the most current and comprehensive information of experimentally validated miRNA-target interactions. The database was launched in 2010 with data sources for >100 published studies in the identification of miRNA targets, molecular networks of miRNA targets and systems biology, and the current release (2013, version 4) includes significant expansions and enhancements over the initial release (2010, version 1). This article reports the current status of and recent improvements to the database, including (i) a 14-fold increase to miRNA-target interaction entries, (ii) a miRNA-target network, (iii) expression profile of miRNA and its target gene, (iv) miRNA target-associated diseases and (v) additional utilities including an upgrade reminder and an error reporting/user feedback system

    Functional properties and evolutionary splicing constraints on a composite exonic regulatory element of splicing in CFTR exon 12

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    In general, splicing regulatory elements are defined as Enhancers or Silencers depending on their positive or negative effect upon exon inclusion. Often, these sequences are usually present separate from each other in exonic/intronic sequences. The Composite Exonic Splicing Regulatory Elements (CERES) represent an extreme physical overlap of enhancer/silencer activity. As a result, when CERES elements are mutated the consequences on the splicing process are difficult to predict. Here, we show that the functional activity of the CERES2 sequence in CFTR exon 12 is regulated by the binding, in very close proximity to each other, of several SR and hnRNP proteins. Moreover, our results show that practically the entire exon 12 sequence context participate in its definition. The consequences of this situation can be observed at the evolutionary level by comparing changes in conservation of different splicing elements in different species. In conclusion, our study highlights how it is increasingly difficult to define many exonic sequences by simply breaking them down in isolated enhancer/silencer or even neutral elements. The real picture is close to one of continuous competition between positive and negative factors where affinity for the target sequences and other dynamic factors decide the inclusion or exclusion of the exon

    IKKβ Suppression of TSC1 Links Inflammation and Tumor Angiogenesis via the mTOR Pathway

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    SummaryTNFα has recently emerged as a regulator linking inflammation to cancer pathogenesis, but the detailed cellular and molecular mechanisms underlying this link remain to be elucidated. The tuberous sclerosis 1 (TSC1)/TSC2 tumor suppressor complex serves as a repressor of the mTOR pathway, and disruption of TSC1/TSC2 complex function may contribute to tumorigenesis. Here we show that IKKβ, a major downstream kinase in the TNFα signaling pathway, physically interacts with and phosphorylates TSC1 at Ser487 and Ser511, resulting in suppression of TSC1. The IKKβ-mediated TSC1 suppression activates the mTOR pathway, enhances angiogenesis, and results in tumor development. We further find that expression of activated IKKβ is associated with TSC1 Ser511 phosphorylation and VEGF production in multiple tumor types and correlates with poor clinical outcome of breast cancer patients. Our findings identify a pathway that is critical for inflammation-mediated tumor angiogenesis and may provide a target for clinical intervention in human cancer

    Pilot Scale Production of Highly Efficacious and Stable Enterovirus 71 Vaccine Candidates

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    BACKGROUND: Enterovirus 71 (EV71) has caused several epidemics of hand, foot and mouth diseases (HFMD) in Asia and now is being recognized as an important neurotropic virus. Effective medications and prophylactic vaccine against EV71 infection are urgently needed. Based on the success of inactivated poliovirus vaccine, a prototype chemically inactivated EV71 vaccine candidate has been developed and currently in human phase 1 clinical trial. PRINCIPAL FINDING: In this report, we present the development of a serum-free cell-based EV71 vaccine. The optimization at each step of the manufacturing process was investigated, characterized and quantified. In the up-stream process development, different commercially available cell culture media either containing serum or serum-free was screened for cell growth and virus yield using the roller-bottle technology. VP-SFM serum-free medium was selected based on the Vero cell growth profile and EV71 virus production. After the up-stream processes (virus harvest, diafiltration and concentration), a combination of gel-filtration liquid chromatography and/or sucrose-gradient ultracentrifugation down-stream purification processes were investigated at a pilot scale of 40 liters each. Although the combination of chromatography and sucrose-gradient ultracentrifugation produced extremely pure EV71 infectious virus particles, the overall yield of vaccine was 7-10% as determined by a VP2-based quantitative ELISA. Using chromatography as the downstream purification, the virus yield was 30-43%. To retain the integrity of virus neutralization epitopes and the stability of the vaccine product, the best virus inactivation was found to be 0.025% formalin-treatment at 37 °C for 3 to 6 days. Furthermore, the formalin-inactivated virion vaccine candidate was found to be stable for >18 months at 4 °C and a microgram of viral proteins formulated with alum adjuvant could induce strong virus-neutralizing antibody responses in mice, rats, rabbits, and non-human primates. CONCLUSION: These results provide valuable information supporting the current cell-based serum-free EV71 vaccine candidate going into human Phase I clinical trials

    Gamification and flipped learning and their influence on aspects related to the teaching-learning process

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    Nowadays, education is going through a moment of methodological transformation. Two of the active methodologies with excellent projection within the educational field are gamification and flipped learning. This study analyzed the methodological contrast between gamification and flipped learning in the subject of Physical Education in three different educational stages to determine the most influential methodology in the training process. Research design was a quasi-experimental research with a sample of 356 students in Spain. Data collection took place with a questionnaire. The results show that gamification as a teaching and learning methodology is better valued at an early stage, while the more aged participants better value the flipped learning methodology. Both methodologies have shown great potential in the development of educational processes in Physical Education. Gamification indeed seems to have positive effects on students from the lower stages. On the other hand, flipped learning produces positive effects on the group stages, pre-university students

    MicroRNA-34a modulates genes involved in cellular motility and oxidative phosphorylation in neural precursors derived from human umbilical cord mesenchymal stem cells

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    <p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cell (MSC) found in bone marrow (BM-MSCs) and the Wharton's jelly matrix of human umbilical cord (WJ-MSCs) are able to transdifferentiate into neuronal lineage cells both <it>in vitro </it>and <it>in vivo </it>and therefore hold the potential to treat neural disorders such as stroke or Parkinson's disease. In bone marrow MSCs, miR-130a and miR-206 have been show to regulate the synthesis of neurotransmitter substance P in human mesenchymal stem cell-derived neuronal cells. However, how neuronal differentiation is controlled in WJ-MSC remains unclear.</p> <p>Methods</p> <p>WJ-MSCs were isolated from human umbilical cords. We subjected WJ-MSCs into neurogenesis by a published protocol, and the miRNome patterns of WJ-MSCs and their neuronal progenitors (day 9 after differentiation) were analyzed by the Agilent microRNA microarray.</p> <p>Results</p> <p>Five miRNAs were enriched in WJ-MSCs, including miR-345, miR-106a, miR-17-5p, miR-20a and miR-20b. Another 11 miRNAs (miR-206, miR-34a, miR-374, miR-424, miR-100, miR-101, miR-323, miR-368, miR-137, miR-138 and miR-377) were abundantly expressed in transdifferentiated neuronal progenitors. Among these miRNAs, miR-34a and miR-206 were the only 2 miRNAs been linked to BM-MSC neurogenesis. Overexpressing miR-34a in cells suppressed the expression of 136 neuronal progenitor genes, which all possess putative miR-34a binding sites. Gene enrichment analysis according to the Gene Ontology database showed that those 136 genes were associated with cell motility, energy production (including those with oxidative phosphorylation, electron transport and ATP synthesis) and actin cytoskeleton organization, indicating that miR-34a plays a critical role in precursor cell migration. Knocking down endogenous miR-34a expression in WJ-MSCs resulted in the augment of WJ-MSC motility.</p> <p>Conclusions</p> <p>Our data suggest a critical role of miRNAs in MSC neuronal differentiation, and miR-34a contributes in neuronal precursor motility, which may be crucial for stem cells to home to the target sites they should be.</p
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