962 research outputs found

    Endoscopic tunneling of HeartMate II left ventricular assist device driveline

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    In vitro flowering in embryogenic cultures of Kinnow mandarin (Citrus nobilis Lour ´ C. deliciosa Tenora)

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    Embryogenic cultures of Kinnow mandarin (C. nobilis Lour × C. deliciosa Tenora) were raised from unfertilized ovules dissected from unopened flower buds of this plant inoculated on MS medium supplemented with 2 mg/L kinetin (KN). In vitro flowering was induced in these cultures by usingdifferent concentrations of KN and sucrose as well as subjecting these cultures to different photoperiods. Maximum percentage (31.94%) of cultures producing flowers and maximum number (5.58) of flowers per culture was observed on MS medium supplemented with KN (2 mg/L) and sucrose40 g/L at 12-h photoperiod

    In vitro micrografting for production of Indian citrus ringspot virus (ICRSV)-free plants of kinnow mandarin (Citrus nobilis Lour X C. deliciosa Tenora)

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    Production of Indian citrus ringspot virus (ICRSV)-free plants from an infected plant of kinnow mandarin (Citrus nobilis Lour 9 C. deliciosa Tenora) is reported. The shoot apices of different sizes (0.2-1.0 mm) excised from the ICRSV-infected plant were micrografted onto decapitated rootstock seedlings of rough lemon (C. jambhiri). Micrograft survival depended on the size of shoot apex and the sucrose concentration of the culture medium. Increase in scion size from 0.2 to 0.7 mm resulted in an increase in micrografting success rate from 30.55 to 51.88%. Further, micrograft survival obtained with 0.2 mm was improved from 30.55 to 38.88% by increasing sucrose concentration in the culture media from 5 to 7.5%. The micrografted plants were tested for ICRSV using ELISA and RT-PCR. All plants raised from 0.2-mm scion were found negative with both ELISA and RT-PCR whereas only 20% of the ELISA negative plants raised from 0.3-mm scion were found negative for ICRSV with RT-PCR. The outcome of this research is the successful establishment, acclimatization and virus testing of micrografted plants

    Essential role of MED1 in the transcriptional regulation of ER-dependent oncogenic miRNAs in breast cancer

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    Mediator complex has been extensively shown to regulate the levels of several protein-coding genes; however, its role in the regulation of miRNAs in humans remains unstudied so far. Here we show that MED1, a Mediator subunit in the Middle module of Mediator complex, is overexpressed in breast cancer and is a negative prognostic factor. The levels of several miRNAs (miR-100-5p, -191-5p, -193b-3p, -205-5p, -326, -422a and -425-5p) were found to be regulated by MED1. MED1 induces miR-191/425 cluster in an estrogen receptor-alpha (ER-\u3b1) dependent manner. Occupancy of MED1 on estrogen response elements (EREs) upstream of miR-191/425 cluster is estrogen and ER-\u3b1-dependent and ER-\u3b1-induced expression of these miRNAs is MED1-dependent. MED1 mediates induction of cell proliferation and migration and the genes associated with it (JUN, FOS, EGFR, VEGF, MMP1, and ERBB4) in breast cancer, which is abrogated when used together with miR-191-inhibition. Additionally, we show that MED1 also regulates the levels of direct miR-191 target genes such as SATB1, CDK6 and BDNF. Overall, the results show that MED1/ER-\u3b1/miR-191 axis promotes breast cancer cell proliferation and migration and may serve as a novel target for therapy

    On the origins of the mitotic shift in proliferating cell layers

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    Background: During plant and animal development, monolayer cell sheets display a stereotyped distribution of polygonal cell shapes. In interphase cells these shapes range from quadrilaterals to decagons, with a robust average of six sides per cell. In contrast, the subset of cells in mitosis exhibits a distinct distribution with an average of seven sides. It remains unclear whether this ‘mitotic shift’ reflects a causal relationship between increased polygonal sidedness and increased division likelihood, or alternatively, a passive effect of local proliferation on cell shape. Methods: We use a combination of probabilistic analysis and mathematical modeling to predict the geometry of mitotic polygonal cells in a proliferating cell layer. To test these predictions experimentally, we use Flp-Out stochastic labeling in the Drosophila wing disc to induce single cell clones, and confocal imaging to quantify the polygonal topologies of these clones as a function of cellular age. For a more generic test in an idealized cell layer, we model epithelial sheet proliferation in a finite element framework, which yields a computationally robust, emergent prediction of the mitotic cell shape distribution. Results: Using both mathematical and experimental approaches, we show that the mitotic shift derives primarily from passive, non-autonomous effects of mitoses in neighboring cells on each cell’s geometry over the course of the cell cycle. Computationally, we predict that interphase cells should passively gain sides over time, such that cells at more advanced stages of the cell cycle will tend to have a larger number of neighbors than those at earlier stages. Validating this prediction, experimental analysis of randomly labeled epithelial cells in the Drosophila wing disc demonstrates that labeled cells exhibit an age-dependent increase in polygonal sidedness. Reinforcing these data, finite element simulations of epithelial sheet proliferation demonstrate in a generic framework that passive side-gaining is sufficient to generate a mitotic shift. Conclusions: Taken together, our results strongly suggest that the mitotic shift reflects a time-dependent accumulation of shared cellular interfaces over the course of the cell cycle. These results uncover fundamental constraints on the relationship between cell shape and cell division that should be general in adherent, polarized cell layers

    Control of the Mitotic Cleavage Plane by Local Epithelial Topology

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    For nearly 150 years, it has been recognized that cell shape strongly influences the orientation of the mitotic cleavage plane (e.g. Hofmeister, 1863). However, we still understand little about the complex interplay between cell shape and cleavage plane orientation in epithelia, where polygonal cell geometries emerge from multiple factors, including cell packing, cell growth, and cell division itself. Here, using mechanical simulations, we show that the polygonal shapes of individual cells can systematically bias the long axis orientations of their adjacent mitotic neighbors. Strikingly, analysis of both animal epithelia and plant epidermis confirm a robust and nearly identical correlation between local cell topology and cleavage plane orientation in vivo. Using simple mathematics, we show that this effect derives from fundamental packing constraints. Our results suggest that local epithelial topology is a key determinant of cleavage plane orientation, and that cleavage plane bias may be a widespread property of polygonal cell sheets in plants and animals.Engineering and Applied Science

    Effect of vitamin D supplementation on blood pressure:a systematic review and meta-analysis incorporating individual patient data

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    D-PRESSURE Collaboration: et al.[Importance]: Low levels of vitamin D are associated with elevated blood pressure (BP) and future cardiovascular events. Whether vitamin D supplementation reduces BP and which patient characteristics predict a response remain unclear.[Objective]: To systematically review whether supplementation with vitamin D or its analogues reduce BP.[Data Sources]: We searched MEDLINE, CINAHL, EMBASE, Cochrane Central Register of Controlled Trials, and http://www.ClinicalTrials.com augmented by a hand search of references from the included articles and previous reviews. Google was searched for gray literature (ie, material not published in recognized scientific journals). No language restrictions were applied. The search period spanned January 1, 1966, through March 31, 2014.[Study Selection]: We included randomized placebo-controlled clinical trials that used vitamin D supplementation for a minimum of 4 weeks for any indication and reported BP data. Studies were included if they used active or inactive forms of vitamin D or vitamin D analogues. Cointerventions were permitted if identical in all treatment arms.[Data Extraction and Synthesis]: We extracted data on baseline demographics, 25-hydroxyvitamin D levels, systolic and diastolic BP (SBP and DBP), and change in BP from baseline to the final follow-up. Individual patient data on age, sex, medication use, diabetes mellitus, baseline and follow-up BP, and 25-hydroxyvitamin D levels were requested from the authors of the included studies. For trial-level data, between-group differences in BP change were combined in a random-effects model. For individual patient data, between-group differences in BP at the final follow up, adjusted for baseline BP, were calculated before combining in a random-effects model.[Main Outcomes and Measures]: Difference in SBP and DBP measured in an office setting.[Results]: We included 46 trials (4541 participants) in the trial-level meta-analysis. Individual patient data were obtained for 27 trials (3092 participants). At the trial level, no effect of vitamin D supplementation was seen on SBP (effect size, 0.0 [95% CI, −0.8 to 0.8] mm Hg; P = .97; I2 = 21%) or DBP (effect size, −0.1 [95% CI, −0.6 to 0.5] mm Hg; P = .84; I2 = 20%). Similar results were found analyzing individual patient data for SBP (effect size, −0.5 [95% CI, −1.3 to 0.4] mm Hg; P = .27; I2 = 0%) and DBP (effect size, 0.2 [95% CI, −0.3 to 0.7] mm Hg; P = .38; I2 = 0%). Subgroup analysis did not reveal any baseline factor predictive of a better response to therapy.[Conclusions and Relevance]: Vitamin D supplementation is ineffective as an agent for lowering BP and thus should not be used as an antihypertensive agent.Peer reviewe

    Femtosecond nonlinear ultrasonics in gold probed with ultrashort surface plasmons

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    Fundamental interactions induced by lattice vibrations on ultrafast time scales become increasingly important for modern nanoscience and technology. Experimental access to the physical properties of acoustic phonons in the THz frequency range and over the entire Brillouin zone is crucial for understanding electric and thermal transport in solids and their compounds. Here, we report on the generation and nonlinear propagation of giant (1 percent) acoustic strain pulses in hybrid gold/cobalt bilayer structures probed with ultrafast surface plasmon interferometry. This new technique allows for unambiguous characterization of arbitrary ultrafast acoustic transients. The giant acoustic pulses experience substantial nonlinear reshaping already after a propagation distance of 100 nm in a crystalline gold layer. Excellent agreement with the Korteveg-de Vries model points to future quantitative nonlinear femtosecond THz-ultrasonics at the nano-scale in metals at room temperature

    Formulation Development and Evaluation of Alginate Microspheres of Ibuprofen

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    The present study was designed to investigate the effects of different variables on the release profile of ibuprofen microspheres formulated using modified emulsification method. Eight batches of microspheres (F1-F8) were prepared by applying 23 factorial design. The amount of sodium alginate, amount of calcium chloride, and amount of magnesium stearate were selected as formulation variables. All the batches were evaluated in terms of percentage yield, percentage encapsulation efficiency and in vitro release characteristics. The batch F7 was found to be optimum batch and was further characterized via scanning electron microscopy (SEM) and particle size analysis. Multiple linear regression was applied to confirm significant effect of each variable on release characteristics. The model developed in the present study can be effectively utilized to achieve the formulation with desired release characteristics
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