372 research outputs found

    Effect of Energy Metabolism on NF-kB activity in Ovarian Cancer

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    NF-kB is a transcription factor involved in cancer cell growth and survival. The activation of NF-kB can be assessed by monitoring phosphorylation of RelA p65 at Ser-536, which is a surrogate of the NF-kB transcription factor activation. The objective of this study was to determine if the loss of ATP leads to NF-kB deficiency and thus, apoptotic cell death of “bad” cells in ovarian cancer cells. The independent variables were metformin (Met), an anti-diabetic medicine, another compound MinB functionally similar to Met and a glucose transporter inhibitor BAY-876. The dependent variables were the resulting effect of Met and MinB on phosphorylated AMPK at Thr-172 (marker of ATP loss) and RelA p65 at Ser-536 (marker of NF-kB activation). In each experiment, AMPK and RelA phosphorylation were tested by treatment of ovarian cancer cell lines with Met, MinB, BAY-876, Met+BAY-876, MinB+BAY-876. Western blotting was performed to determine the phosphorylation levels of AMPK and RelA p65. For two gels, the process was repeated. In each gel, Met or MinB treatment leads to thicker bands of AMPK-p, indicating decrease in cellular ATP levels following treatments. The effect of Met, MinB, or BAY-876 on RelA p65 was limited. However, co-treatment of Met or MinB with BAY-876 caused strong inhibition of NF-kB, as reflected by reduction in RelA p65-p. These results suggested that ATP deficiency together with inhibition of glucose transport cause inactivation of NK-kB. Future research will be conducted to study the effects of these compounds or their combinations on ovarian cancer cell growth and survival against from apoptosis.https://scholarscompass.vcu.edu/uresposters/1267/thumbnail.jp

    Salivary Gland Determination in Drosophila: A Salivary-Specific, fork head Enhancer Integrates Spatial Pattern and Allows fork head Autoregulation

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    AbstractIn the early Drosophila embryo, a system of coordinates is laid down by segmentation genes and dorsoventral patterning genes. Subsequently, these coordinates must be interpreted to define particular tissues and organs. To begin understanding this process for a single organ, we have studied how one of the first salivary gland genes, fork head (fkh), is turned on in the primordium of this organ, the salivary placode. A placode-specific fkh enhancer was identified 10 kb from the coding sequence. Dissection of this enhancer showed that the apparently homogeneous placode is actually composed of at least four overlapping domains. These domains appear to be developmentally important because they predict the order of salivary invagination, are evolutionarily conserved, and are regulated by patterning genes that are important for salivary development. Three dorsoventral domains are defined by EGF receptor (EGFR) signaling, while stripes located at the anterior and posterior edges of the placode depend on wingless signaling. Further analysis identified sites in the enhancer that respond either positively to the primary activator of salivary gland genes, SEX COMBS REDUCED (SCR), or negatively to EGFR signaling. These results show that fkh integrates spatial pattern directly, without reference to other early salivary gland genes. In addition, we identified a binding site for FKH protein that appears to act in fkh autoregulation, keeping the gene active after SCR has disappeared from the placode. This autoregulation may explain how the salivary gland maintains its identity after the organ is established. Although the fkh enhancer integrates information needed to define the salivary placode, and although fkh mutants have the most extreme effects on salivary gland development thus far described, we argue that fkh is not a selector gene for salivary gland development and that there is no master, salivary gland selector gene. Instead, several genes independently sense spatial information and cooperate to define the salivary placode

    Nasal septal angle deviation: effect on lateral wall in nasal obstruction

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    Background: Deviation of the nasal septum (DNS) refers to the convexity of the septum to one side disturbing the nasal physiology with obstructed nasal breathing leading to lateral nasal wall abnormalities and paranasal sinuses (PNS) mucosal disease. Knowledge of nasal morphological parameters plays an important role in planning successful nasal surgery. Our aim was to evaluate the angle of septal deviation (ASD) on CT scan and study its influence on the lateral nasal wall abnormalities and PNS mucosal disease.Methods: A prospective cross-sectional observational study was conducted on 130 patients with clinical evidence of DNS and chronic sinusitis. The direction and severity of DNS was recorded on CT scan along with evaluation of lateral nasal wall and sinus mucosal abnormalities.Results: Increasing ASD had statistically significant correlation with the lateral nasal wall abnormalities, most commonly, contralateral middle and inferior turbinate hypertrophy (p-value <0.0001). No significant association was found with the incidence of ipsilateral or contralateral osteomeatal complex (OMC) obstruction and sinus mucosal disease.Conclusions: The direction and severity of septal deviation has significant impact on contralateral middle and inferior turbinate hypertrophy. The analysis of these ancillary pathologies can be of great help to the surgeon in better management of patients with nasal obstruction

    Diagnostic accuracy of an integrated approach using conventional ultrasonography, and Doppler and strain elastography in the evaluation of superficial soft tissue lesions

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    Introduction: To assess the diagnostic accuracy of an integrated approach using conventional ultrasonography, colour Doppler ultrasonography, and elastography strain ratios in tandem in the evaluation of superficial soft tissue lesions. Material and methods: Sixty-five subjects were included in this prospective cross-sectional study. Greyscale features and Doppler parameters were recorded. Strain elastography of the non-vascular and non-cystic lesions was performed and strain ratios were calculated. Fine-needle aspiration or biopsy of all the lesions was performed depending on their site and condition. Inter-rater k agreement was used to determine the strength of agreement between imaging-based diagnosis and histopathological diagnosis. A diagnostic test was used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value. A p value of < 0.05 was considered statistically significant. Results: Multiple superficial soft tissue lesions were studied, the majority of which were lipomas, vascular anomalies, and epidermoid cysts. The diagnostic accuracy was very high and varied from 92.31% to 100% for various masses. The imaging-based diagnosis was in agreement with the histopathological diagnosis in 86.15% (n = 56) and disagreement in 13.85% (n = 9) of the cases (p < 0.007). There was very good inter-rater agreement between the imaging-based diagnosis and histopathological diagnosis (Îş = 0.818). Conclusions: The combined use of conventional ultrasonography, colour Doppler, and elastography strain ratios provides a very effective non-invasive tool for the diagnosis of superficial soft tissue lesions and may negate the need for unnecessary biopsies. The advantage of this integrated approach using various ultrasound techniques needs no further emphasis

    Computational studies for reduced graphene oxide in hydrogen-rich environment

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    We employ molecular dynamic simulations to study the reduction process of graphene-oxide (GO) in a chemically active environment enriched with hydrogen. We examine the concentration and pressure of hydrogen gas as a function of temperature in which abstraction of oxygen is possible with minimum damage to C-sp2^2 bonds hence preserving the integrity of the graphene sheet. Through these studies we find chemical pathways that demonstrate beneficiary mechanisms for the quality of graphene including formation of water as well as suppression of carbonyl pair holes in favor of hydroxyl and epoxy formation facilitated by hydrogen gas in the environment.Comment: 9 pages and 9 figures. Animations and movies are available at: http://qmsimulatorgojpc.wordpress.com

    Reactive Molecular Dynamics study on the first steps of DNA-damage by free hydroxyl radicals

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    We employ a large scale molecular simulation based on bond-order ReaxFF to simulate the chemical reaction and study the damage to a large fragment of DNA-molecule in the solution by ionizing radiation. We illustrate that the randomly distributed clusters of diatomic OH-radicals that are primary products of megavoltage ionizing radiation in water-based systems are the main source of hydrogen-abstraction as well as formation of carbonyl- and hydroxyl-groups in the sugar-moiety that create holes in the sugar-rings. These holes grow up slowly between DNA-bases and DNA-backbone and the damage collectively propagate to DNA single and double strand break.Comment: 6 pages and 8 figures. movies and simulations are available at: http://qmsimulator.wordpress.com

    Sonic Hedgehog Is a Chemoattractant for Midbrain Dopaminergic Axons

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    Midbrain dopaminergic axons project from the substantia nigra (SN) and the ventral tegmental area (VTA) to rostral target tissues, including the striatum, pallidum, and hypothalamus. The axons from the medially located VTA project primarily to more medial target tissues in the forebrain, whereas the more lateral SN axons project to lateral targets including the dorsolateral striatum. This structural diversity underlies the distinct functions of these pathways. Although a number of guidance cues have been implicated in the formation of the distinct axonal projections of the SN and VTA, the molecular basis of their diversity remains unclear. Here we investigate the molecular basis of structural diversity in mDN axonal projections. We find that Sonic Hedgehog (Shh) is expressed at a choice point in the course of the rostral dopaminergic projections. Furthermore, in midbrain explants, dopaminergic projections are attracted to a Shh source. Finally, in mice in which Shh signaling is inactivated during late neuronal development, the most medial dopaminergic projections are deficient

    Dislocations and Grain Boundaries in Two-Dimensional Boron Nitride

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    A new dislocation structure-square-octagon pair (4|8) is discovered in two-dimensional boron nitride (h-BN), via first-principles calculations. It has lower energy than corresponding pentagon-heptagon pairs (5|7), which contain unfavorable homo-elemental bonds. Based on the structures of dislocations, grain boundaries (GB) in BN are investigated. Depending on the tilt angle of grains, GB can be either polar (B-rich or N-rich), constituted by 5|7s, or un-polar, composed of 4|8s. The polar GBs carry net charges, positive at B-rich and negative at N-rich ones. In contrast to GBs in graphene which generally impede the electronic transport, polar GBs have smaller bandgap compared to perfect BN, which may suggest interesting electronic and optic applications

    Neuropilin-2 Mediated β-Catenin Signaling and Survival in Human Gastro-Intestinal Cancer Cell Lines

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    NRP-2 is a high-affinity kinase-deficient receptor for ligands belonging to the class 3 semaphorin and vascular endothelial growth factor families. NRP-2 has been detected on the surface of several types of human cancer cells, but its expression and function in gastrointestinal (GI) cancer cells remains to be determined. We sought to determine the function of NRP-2 in mediating downstream signals regulating the growth and survival of human gastrointestinal cancer cells. In human gastric cancer specimens, NRP-2 expression was detected in tumor tissues but not in adjacent normal mucosa. In CNDT 2.5 cells, shRNA mediated knockdown NRP-2 expression led to decreased migration and invasion in vitro (p<0.01). Focused gene-array analysis demonstrated that loss of NRP-2 reduced the expression of a critical metastasis mediator gene, S100A4. Steady-state levels and function of β-catenin, a known regulator of S100A4, were also decreased in the shNRP-2 clones. Furthermore, knockdown of NRP-2 sensitized CNDT 2.5 cells in vitro to 5FU toxicity. This effect was associated with activation of caspases 3 and 7, cleavage of PARP, and downregulation of Bcl-2. In vivo growth of CNDT 2.5 cells in the livers of nude mice was significantly decreased in the shNRP-2 group (p<0.05). Intraperitoneal administration of NRP-2 siRNA-DOPC decreased the tumor burden in mice (p = 0.01). Collectively, our results demonstrate that tumor cell–derived NRP-2 mediates critical survival signaling in gastrointestinal cancer cells
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