455 research outputs found

    Detection of Ubiquitination on Syk and Documenting Syk Stability

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    Post-translational modifications regulate the activities of proteins important to numerous diseases. Spleen Tyrosine Kinase (Syk) is particularly interesting to researchers because it modifies many targets and plays multiple roles in regulating cells in our bodies and its abnormal modifications may contribute to cancer, Alzheimer’s disease and allergies. In an attempt to study these modifications of Syk, we first looked at detecting ubiquitination on Syk protein. Ubiquitin, a small 8 kDa molecule, attaches to lysine residues on protein. The attachment of ubiquitin to Syk may cause Syk to either propagate signals onwards to activate other proteins or signal it to undergo proteasomal degradation. To detect ubiquitination of Syk, B cell lymphoma DG75 with endogenous Syk expression was electroporated with HA-tagged Ubiquitin expression vector to introduce the ubiquitin molecule into the cells. Immunoprecipitation of Syk was performed to isolate the total Syk and to visualize the ubiquitination by Western Blot with anti-HA antibody. When cells were treated with Cyclohexamide (CHX), a protein translation inhibitor, we did not observe significant decrease of Syk in protein level, indicating that Syk is an exceptionally stable protein with a half-life longer than 72 hours. Upon treatment of cells with both CHX and MG132, a proteasome inhibitor, we reproducibly observed a detectable accumulation of Syk protein in 24 hours. The established technique will not only facilitate the study of the impact of ubiquitination on Syk in signal transduction, it also will lead us to identify the potential significance of ubiquinated lysine residues on Syk in cellular function

    Hyperbaric oxygen therapy as an adjunctive treatment for sternal infection and osteomyelitis after sternotomy and cardiothoracic surgery

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    <p>Abstract</p> <p>Purpose</p> <p>A retrospective study to evaluate the effect of hyperbaric oxygen (HBO2) therapy on sternal infection and osteomyelitis following median sternotomy.</p> <p>Materials and methods</p> <p>A retrospective analysis of patients who received sternotomy and cardiothoracic surgery which developed sternal infection and osteomyelitis between 2002 and 2009. Twelve patients who received debridement and antibiotic treatment were selected, and six of them received additional HBO2 therapy. Demographic, clinical characteristics and outcome were compared between patients with and without HBO2 therapy.</p> <p>Results</p> <p>HBO2 therapy did not cause any treatment-related complication in patients receiving this additional treatment. Comparisons of the data between two study groups revealed that the length of stay in ICU (8.7 ± 2.7 days vs. 48.8 ± 10.5 days, p < 0.05), duration of invasive (4 ± 1.5 days vs. 34.8 ± 8.3 days, p < 0.05) and non-invasive (4 ± 1.9 days vs. 22.3 ± 6.2 days, p < 0.05) positive pressure ventilation were all significantly lower in patients with additional HBO2 therapy, as compared to patients without HBO2 therapy. Hospital mortality was also significantly lower in patients who received HBO2 therapy (0 case vs. 3 cases, p < 0.05), as compared to patients without the HBO2 therapy.</p> <p>Conclusions</p> <p>In addition to primary treatment with debridement and antibiotic use, HBO2 therapy may be used as an adjunctive and safe treatment to improve clinical outcomes in patients with sternal infection and osteomyelitis after sternotomy and cardiothoracic surgery.</p

    Melanogenesis Inhibitor(s) from Phyla nodiflora

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    Overexpression of tyrosinase can cause excessive production of melanin and lead to hyperpigmentation disorders, including melasma and freckles. Recently, agents obtained from plants are being used as alternative medicines to downregulate tyrosinase synthesis and decrease melanin production. Phyla nodiflora Greene (Verbenaceae) is used as a folk medicine in Taiwanese for treating and preventing inflammatory diseases such as hepatitis and dermatitis. However, the antimelanogenesis activity and molecular biological mechanism underlying the activity of the methanolic extract of P. nodiflora (PNM) have not been investigated to date. Our results showed that PNM treatment was not cytotoxic and significantly reduced the cellular melanin content and tyrosinase activity in a dose-dependent manner (P<0.05). Further, PNM exhibited a significant antimelanogenesis effect (P<0.05) by reducing the levels of phospho-cAMP response element-binding protein and microphthalmia-associated transcription factor (MITF), inhibiting the synthesis of tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2, and decreasing the cellular melanin content. Moreover, PNM significantly activated the phosphorylation of mitogen-activated protein kinases, including phospho-extracellular signal-regulated kinase, c-Jun N-terminal kinase, and phospho-p38, and inhibited the synthesis of MITF, thus decreasing melanogenesis. These properties suggest that PNM could be used as a clinical and cosmetic skin-whitening agent to cure and/or prevent hyperpigmentation

    Peripheral primitive neuroectodermal tumor of the ovary with torsion

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    AbstractPeripheral primitive neuroectodermal tumors (pPNETs) of the ovary are rare monophasic teratomas, and fewer than 100 cases have been reported in the literature. pPNETs mainly involve young women during their reproductive age, therefore, accurate diagnosis followed by multimodal treatment should be taken into consideration for fertility preservation. We report a patient with stage IA pPNET of the ovary presenting with acute abdominal pain secondary to torsion that was successfully managed by fertility-sparing surgery and six courses of combination chemotherapy with vincristine, Adriamycin, and cyclophosphamide. She has had a disease-free survival of >3 years. This brief review demonstrates the clinical course of pPNET and summarizes the literature to show that clinical stage at the time of diagnosis is the most important prognostic factor and that the vast majority of recurrences are observed within 10 years

    Tequila Regulates Insulin-Like Signaling and Extends Life Span in Drosophila melanogaster

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    The aging process is a universal phenomenon shared by all living organisms. The identification of longevity genes is important in that the study of these genes is likely to yield significant insights into human senescence. In this study, we have identified Tequila as a novel candidate gene involved in the regulation of longevity in Drosophila melanogaster. We have found that a hypomorphic mutation of Tequila (Teq(f01792)), as well as cell-specific downregulation of Tequila in insulin-producing neurons of the fly, significantly extends life span. Tequila deficiency-induced life-span extension is likely to be associated with reduced insulin-like signaling, because Tequila mutant flies display several common phenotypes of insulin dysregulation, including reduced circulating Drosophila insulin-like peptide 2 (Dilp2), reduced Akt phosphorylation, reduced body size, and altered glucose homeostasis. These observations suggest that Tequila may confer life-span extension by acting as a modulator of Drosophila insulin-like signaling

    Optimal Design of Plasticizing Screw Using Artificial Intelligent Approach

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    This study integrated plasticizing screw analysis software with neural-network in the design of a screw for injection molding application. The qualities of the plasticizing screw selected in this study are output rate, melt temperature variation at the end of metering zone, the specific mechanical energy (SME), and the melting distance. The Taguchi orthogonal array is implemented to carry out the experiment and to obtain the test data for training the neural network. The Back-propagation Neural Network (BPNN) was then used for screw quality predictor, and optimal design was solved with Genetic Algorithm (GA). The optimal screw design for a diameter of 25 mm screw for molding PC resin in this study is 5.37D in solid conveying zone, 9D in compression zone, metering zone depth of 2.44 mm, and flight width of 3 mm. The performance of this screw with the preset processing condition can have the temperature difference at the end of metering (ΔT) of 5.67℃, the output rate Q of 20.12 kg/h, the SME of 520.80 (kJ/kg), and the plastics completely melted at 17.39D

    A Model of Technological Imagination and Creativity: Cognitive Task Analysis

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    An integrated model of cognitive tasks involved in the process of a technological innovation was proposed based on these theories: 1. CDIO theory of technological innovation, 2. Wallas’s creative thinking processes, 3. Khalr & Simon’s theory of scientific discovery, and 4. the conceptual combination theory of imagination. The central theme of this model is the proposition that three cognitive conditions are necessary for technological imagination and innovation: 1. cross-domain knowledge, 2. simple heuristics, and 3. pattern recognition ability. Although the required domain knowledge and implementation methods are different across domains, heuristics that lead to a breakthrough at each phase of CDIO in a technological innovation are similar, with conceptual combination as the cognitive engine for generating original and imaginative ideas

    The mERG1a channel modulates skeletal muscle MuRF1, but not MAFbx, expression.

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    INTRODUCTION: We investigated the mechanism by which the MERG1a K+ channel increases ubiquitin proteasome proteolysis (UPP). METHODS: Hindlimb suspension and electro-transfer of Merg1a cDNA into mouse gastrocnemius muscles induced atrophy. RESULTS: Atrophic gastrocnemius muscles of hindlimb-suspended mice express Merg1a, Murf1, and Mafbx genes. Electrotransfer of Merg1a significantly decreases muscle fiber size (12.6%) and increases UPP E3 ligase Murf1 mRNA (2.1-fold) and protein (23.7%), but does not affect Mafbx E3 ligase expression. Neither Merg1a-induced decreased fiber size nor Merg1a-induced increased Murf1 expression is curtailed significantly by coexpression of inactive HR-Foxo3a, a gene encoding a transcription factor known to induce Mafbx expression. CONCLUSIONS: The MERG1a K+ channel significantly increases expression of Murf1, but not Mafbx. We explored this expression pattern by expressing inactive Foxo3a and showing that it is not involved in MERG1a-mediated expression of Murf1. These findings suggest that MERG1a may not modulate Murf1 expression through the AKT/FOXO pathway

    Food Supplement 20070721-GX May Increase CD34+ Stem Cells and Telomerase Activity

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    Few rejuvenation and antiaging markers are used to evaluate food supplements. We measured three markers in peripheral blood to evaluate the antiaging effects of a food supplement containing placental extract. Samples were evaluated for CD34+ cells, insulin-like growth factor 1 (IGF1), and telomerase activity, which are all markers related to aging. To control the quality of this food supplement, five active components were monitored. In total, we examined 44 individuals who took the food supplement from 1.2 months to 23 months; the average number of CD34+ cells was almost 6-fold higher in the experimental group compared with the control group. Food supplement intake did not change serum IGF1 levels significantly. Finally, the average telomerase activity was 30% higher in the subjects taking this food supplement. In summary, our results suggest that the placental extract in the food supplement might contribute to rejuvenation and antiaging
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