56 research outputs found

    Electrospun Polycaprolactone Nanofiber Scaffolds for Tissue Engineering

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    Stem cell and tissue engineering offer us with a unique opportunity to research and develop new therapies for treating various diseases that are otherwise incurable using traditional medicines. However, development of these new therapies replies upon the establishment of in vitro cell culture and differentiation systems that mimic in vivo microenvironments required for cell-cell and cell-ECM interaction. The development of these cell culture systems depends upon the identification of appropriate biomaterials and cell sources. Biomaterials should be carefully selected and fabricated into scaffolds for supporting cell growth and differentiation. In this study, we explored the fabrication of 3D electrospun nanofiber scaffolds and demonstrated the feasibility of using these scaffolds for supporting cell growth. The material that we used for scaffold fabrication is a polymer, polycaprolactone (PCL). We discovered that the electrospun PCL nanofibers are highly hydrophobic, unsuitable for cell growth. The treatment of PCL electrospun nanofibers with oxygen plasma treatment endowed the fibers with hydrophilic property, making them suitable for cell growth. Our studies suggested that the length of oxygen plasma treatment considerably influences the water contact degree of the nanofibers and their hydrophilicity. The optimization of oxygen plasma treatment resulted in significant improvement of cell proliferation within the electrospun nanofiber scaffolds. Our results provide insight into plasma treatment effects on electrospun PCL as they relate to material properties and cell growth

    TGF-β promotes microtube formation in glioblastoma through Thrombospondin 1

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    International audienceAbstract Background Microtubes (MTs), cytoplasmic extensions of glioma cells, are important cell communication structures promoting invasion and treatment resistance through network formation. MTs are abundant in chemoresistant gliomas, in particular, glioblastomas (GBMs), while they are uncommon in chemosensitive IDH-mutant and 1p/19q co-deleted oligodendrogliomas. The aim of this study was to identify potential signaling pathways involved in MT formation. Methods Bioinformatics analysis of TCGA was performed to analyze differences between GBM and oligodendroglioma. Patient-derived GBM stem cell lines were used to investigate MT formation under transforming growth factor-beta (TGF-β) stimulation and inhibition in vitro and in vivo in an orthotopic xenograft model. RNA sequencing and proteomics were performed to detect commonalities and differences between GBM cell lines stimulated with TGF-β. Results Analysis of TCGA data showed that the TGF-β pathway is highly activated in GBMs compared to oligodendroglial tumors. We demonstrated that TGF-β1 stimulation of GBM cell lines promotes enhanced MT formation and communication via calcium signaling. Inhibition of the TGF-β pathway significantly reduced MT formation and its associated invasion in vitro and in vivo. Downstream of TGF-β, we identified thrombospondin 1 (TSP1) as a potential mediator of MT formation in GBM through SMAD activation. TSP1 was upregulated upon TGF-β stimulation and enhanced MT formation, which was inhibited by TSP1 shRNAs in vitro and in vivo. Conclusion TGF-β and its downstream mediator TSP1 are important mediators of the MT network in GBM and blocking this pathway could potentially help to break the complex MT-driven invasion/resistance network

    Health-related quality of life in transplant ineligible newly diagnosed multiple myeloma patients treated with either thalidomide or lenalidomide-based regimen until progression: a prospective, open-label, multicenter, randomized, phase 3 study

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    Data on the impact of long term treatment with immunomodulatory drugs (IMiD) on health-related quality of life (HRQoL) is limited. The HOVON-87/NMSG18 study was a randomized, phase 3 study in newly diagnosed transplant ineligible patients with multiple myeloma, comparing melphalan-prednisolone in combination with thalidomide or lenalidomide, followed by maintenance therapy until progression (MPT-T or MPR-R). The EORTC QLQ-C30 and MY20 questionnaires were completed at baseline, after three and nine induction cycles and six and 12 months of maintenance therapy. Linear mixed models and minimal important differences were used for evaluation. 596 patients participated in HRQoL reporting. Patients reported clinically relevant improvement in global quality of life (QoL), future perspective and role and emotional functioning, and less fatigue and pain in both arms. The latter being of large effect size

    Fluid-Structure Interaction Simulation Of Submerged Floating Tunnels

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    . A two-dimensional section model of the submerged tunnel problem is analyzed with the multiphysics finite element code SPECTRUM. The model consist of a circular cylinder submerged in sea water and subjected to constant current and regular waves. The waves are modeled by prescribing the velocity profile along the inflow boundary according to linear wave theory and by using free surface boundary conditions on the water surface. Structural boundary conditions are consistent with a global model of the submerged tunnel. A detail description of the computational model and the solution strategy that is used to solve this problem is given. The global response parameters of the cylinder (force coefficients, displacements, velocities and accelerations) obtained from the FSI-simulations are compared with a global nonlinear analysis of the tunnel using simplified models for representing the environmental loads. Knut M. Okstad, Terje Haukas, Svein Remseth and Kjell M. Mathisen 1 INTRODUCTION Be..

    Increased risk of bradycardia in vigorous infants receiving early as compared to delayed cord clamping at birth

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    OBJECTIVE: To compare HR pattern of vigorous newborns during the first 180 s with early (<= 60 s, ECC) or delayed (>60 s, DCC) cord clamping. STUDY DESIGN: Observational study including dry-electrode ECG monitoring of 610 vaginally-born singleton term and late-preterm (>= 34 weeks) who were vigorous after birth. RESULTS: 198 received ECC while 412 received DCC with median cord clamping at 37 s and 94 s. Median HR remained stable from 30 to 180 s with DCC (172 and 170 bpm respectively) but increased with ECC (169 and 184 bpm). The proportion with bradycardia was higher among ECC than DCC at 30 s and fell faster in the DCC through 60 s. After adjusting for factors affecting timing of cord clamping, ECC had significant risk of bradycardia compared to DCC (aRR 1.51; 95% CI; 1.01-2.26). CONCLUSION: Early heart instability and higher risk of bradycardia with ECC as compared to DCC supports the recommended clinical practice of DCC
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