113 research outputs found

    An image cytometric technique is a concise method to detect adenoviruses and host cell proteins and to monitor the infection and cellular responses induced

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    BackgroundGenetically modified adenoviruses (Ad) with preferential replications in tumor cells have been examined for a possible clinical applicability as an anti-cancer agent. A simple method to detect viral and cellular proteins is valuable to monitor the viral infections and to predict the Ad-mediated cytotoxicity.MethodsWe used type 5 Ad in which the expression of E1A gene was activated by 5â€Č-regulatory sequences of genes that were augmented in the expression in human tumors. The Ad were further modified to have the fiber-knob region replaced with that derived from type 35 Ad. We infected human mesothelioma cells with the fiber-replaced Ad, and sequentially examined cytotoxic processes together with an expression level of the viral E1A, hexon, and cellular cleaved caspase-3 with image cytometric and Western blot analyses.ResultsThe replication-competent Ad produced cytotoxicity on mesothelioma cells. The infected cells expressed E1A and hexon 24 h after the infection and then showed cleavage of caspase-3, all of which were detected with image cytometry and Western blot analysis. Image cytometry furthermore demonstrated that increased Ad doses did not enhance an expression level of E1A and hexon in an individual cell and that caspase-3-cleaved cells were found more frequently in hexon-positive cells than in E1A-positive cells. Image cytometry thus detected these molecular changes in a sensitive manner and at a single cell level. We also showed that an image cytometric technique detected expression changes of other host cell proteins, cyclin-E and phosphorylated histone H3 at a single cell level.ConclusionsImage cytometry is a concise procedure to detect expression changes of Ad and host cell proteins at a single cell level, and is useful to analyze molecular events after the infection

    Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Emissions of particulate matter and sulfur dioxide from vehicles and brick kilns and their impacts on air quality in the Kathmandu Valley, Nepal

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    Air pollution is one of the most pressing environmental issues in the Kathmandu Valley, where the capital city of Nepal is located. We estimated emissions from two of the major source types in the valley (vehicles and brick kilns) and analyzed the corresponding impacts on regional air quality. First, we estimated the on-road vehicle emissions in the valley using the International Vehicle Emissions (IVE) model with local emissions factors and the latest available data for vehicle registration. We also identified the locations of the brick kilns in the Kathmandu Valley and developed an emissions inventory for these kilns using emissions factors measured during the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) field campaign in April 2015. Our results indicate that the commonly used global emissions inventory, the Hemispheric Transport of Air Pollution (HTAP_v2.2), underestimates particulate matter emissions from vehicles in the Kathmandu Valley by a factor greater than 100. HTAP_v2.2 does not include the brick sector and we found that our sulfur dioxide (SO2) emissions estimates from brick kilns are comparable to 70 % of the total SO2 emissions considered in HTAP_v2.2. Next, we simulated air quality using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) for April 2015 based on three different emissions scenarios: HTAP only, HTAP with updated vehicle emissions, and HTAP with both updated vehicle and brick kilns emissions. Comparisons between simulated results and observations indicate that the model underestimates observed surface elemental carbon (EC) and SO2 concentrations under all emissions scenarios. However, our updated estimates of vehicle emissions significantly reduced model bias for EC, while updated emissions from brick kilns improved model performance in simulating SO2. These results highlight the importance of improving local emissions estimates for air quality modeling. We further find that model overestimation of surface wind leads to underestimated air pollutant concentrations in the Kathmandu Valley. Future work should focus on improving local emissions estimates for other major and underrepresented sources (e.g., crop residue burning and garbage burning) with a high spatial resolution, as well as the model\u27s boundary layer representation, to capture strong spatial gradients of air pollutant concentrations

    CA-ARBAC: privacy preserving using context-aware role-based access control on Android permission system

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    Existing mobile platforms are based on manual way of granting and revoking permissions to applications. Once the user grants a given permission to an application, the application can use it without limit, unless the user manually revokes the permission. This has become the reason for many privacy problems because of the fact that a permission that is harmless at some occasion may be very dangerous at another condition. One of the promising solutions for this problem is context-aware access control at permission level that allows dynamic granting and denying of permissions based on some predefined context. However, dealing with policy configuration at permission level becomes very complex for the user as the number of policies to configure will become very large. For instance, if there are A applications, P permissions, and C contexts, the user may have to deal with A × P × C number of policy configurations. Therefore, we propose a context-aware role-based access control model that can provide dynamic permission granting and revoking while keeping the number of policies as small as possible. Although our model can be used for all mobile platforms, we use Android platform to demonstrate our system. In our model, Android applications are assigned roles where roles contain a set of permissions and contexts are associated with permissions. Permissions are activated and deactivated for the containing role based on the associated contexts. Our approach is unique in that our system associates contexts with permissions as opposed to existing similar works that associate contexts with roles. As a proof of concept, we have developed a prototype application called context-aware Android role-based access control. We have also performed various tests using our application, and the result shows that our model is working as desired

    Cytotoxicity of replication-competent adenoviruses powered by an exogenous regulatory region is not linearly correlated with the viral infectivity/gene expression or with the E1A-activating ability but is associated with the p53 genotypes

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    BackgroundReplication-competent adenoviruses (Ad) produced cytotoxic effects on infected tumors and have been examined for the clinical applicability. A biomarkers to predict the cytotoxicity is valuable in a clinical setting.MethodsWe constructed type 5 Ad (Ad5) of which the expression of E1A gene was activated by a 5â€Č regulatory sequences of survivin, midkine or cyclooxygenase-2, which were highly expressed in human tumors. We also produced the same replication-competent Ad of which the fiber-knob region was replaced by that of Ad35 (AdF35). The cytotoxicity was examined by a colorimetric assay with human tumor cell lines, 4 kinds of pancreatic, 9 esophageal carcinoma and 5 mesothelioma. Ad infectivity and Ad-mediated gene expression were examined with replication-incompetent Ad5 and AdF35 which expressed the green fluorescence protein gene. Expression of cellular receptors for Ad5 and AdF35 was also examined with flow cytometry. A transcriptional activity of the regulatory sequences was investigated with a luciferase assay in the tumor cells. We then investigated a possible correlation between Ad-mediated cytotoxicity and the infectivity/gene expression, the transcriptional activity or the p53 genotype.ResultsWe found that the cytotoxicity was greater with AdF35 than with Ad5 vectors, but was not correlated with the Ad infectivity/gene expression irrespective of the fiber-knob region or the E1A-activating transcriptional activity. In contrast, replication-competent Ad produced greater cytotoxicity in p53 mutated than in wild-type esophageal carcinoma cells, suggesting a possible association between the cytotoxicity and the p53 genotype.ConclusionsSensitivity to Ad-mediated cytotoxic activity was linked with the p53 genotype but was not lineally correlated with the infectivity/gene expression or the E1A expression

    A cardinal role for cathepsin D in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci

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    The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function

    Inhibition of CLIC4 Enhances Autophagy and Triggers Mitochondrial and ER Stress-Induced Apoptosis in Human Glioma U251 Cells under Starvation

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    CLIC4/mtCLIC, a chloride intracellular channel protein, localizes to mitochondria, endoplasmic reticulum (ER), nucleus and cytoplasm, and participates in the apoptotic response to stress. Apoptosis and autophagy, the main types of the programmed cell death, seem interconnected under certain stress conditions. However, the role of CLIC4 in autophagy regulation has yet to be determined. In this study, we demonstrate upregulation and nuclear translocation of the CLIC4 protein following starvation in U251 cells. CLIC4 siRNA transfection enhanced autophagy with increased LC3-II protein and puncta accumulation in U251 cells under starvation conditions. In that condition, the interaction of the 14-3-3 epsilon isoform with CLIC4 was abolished and resulted in Beclin 1 overactivation, which further activated autophagy. Moreover, inhibiting the expression of CLIC4 triggered both mitochondrial apoptosis involved in Bax/Bcl-2 and cytochrome c release under starvation and endoplasmic reticulum stress-induced apoptosis with CHOP and caspase-4 upregulation. These results demonstrate that CLIC4 nuclear translocation is an integral part of the cellular response to starvation. Inhibiting the expression of CLIC4 enhances autophagy and contributes to mitochondrial and ER stress-induced apoptosis under starvation

    Beth Levine in memoriam

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    Beth Levine was born on 7 April 1960 in Newark, New Jersey. She went to college at Brown University where she received an A.B. Magna Cum Laude, and she attended medical school at Cornell University Medical College, receiving her MD in 1986. She completed her internship and residency in Internal Medicine at Mount Sinai Hospital in New York, and her fellowship in Infectious Diseases at The Johns Hopkins Hospital. Most recently, Beth was a Professor of Internal Medicine and Microbiology, Director of the Center for Autophagy Research, and holder of the Charles Sprague Distinguished Chair in Biomedical Science at the University of Texas Southwestern Medical Center in Dallas. Beth died on 15 June 2020 from cancer. Beth is survived by her husband, Milton Packer, and their two children, Rachel (26 years old) and Ben (25 years old). Dr. Levine was as an international leader in the field of autophagy research. Her laboratory identified the mammalian autophagy gene BECN1/beclin 1; identified conserved mechanisms underlying the regulation of autophagy (e.g. BCL2-BECN1 complex formation, insulin-like signaling, EGFR, ERBB2/HER2 and AKT1-mediated BECN1 phosphosphorylation); and provided the first evidence that autophagy genes are important in antiviral host defense, tumor suppression, lifespan extension, apoptotic corpse clearance, metazoan development, Na,K-ATPase-regulated cell death, and the beneficial metabolic effects of exercise. She developed a potent autophagy-inducing cell permeable peptide, Tat-beclin 1, which has potential therapeutic applications in a range of diseases. She was a founding Associate Editor of the journal Autophagy and an editorial board member of Cell and Cell Host & Microbe. She has received numerous awards/honors in recognition of her scientific achievement, including: The American Cancer Society Junior Faculty Research Award (1994); election into the American Society of Clinical Investigation (2000); the Ellison Medical Foundation Senior Scholars Award in Global Infectious Diseases (2004); elected member, American Association of Physicians (2005); appointment as a Howard Hughes Medical Institute Investigator (2008); Edith and Peter O’Donnell Award in Medicine (2008); elected fellow, American Association for the Advancement of Science (2012); election into the National Academy of Sciences (2013); election into the Academy of Medicine, Engineering and Science of Texas (2013); the ASCI Stanley J. Korsmeyer Award (2014); Phyllis T. Bodel Women in Medicine Award, Yale University School of Medicine (2018); recipient, Barcroft Medal, Queen’s University Belfast (2018).Fil: An, Zhenyi. No especifĂ­ca;Fil: Ballabi, Andrea. No especifĂ­ca;Fil: Bennett, Lynda. No especifĂ­ca;Fil: Boya, Patricia. No especifĂ­ca;Fil: Cecconi, Francesco. No especifĂ­ca;Fil: Chiang, Wei Chung. No especifĂ­ca;Fil: Codogno, Patrice. No especifĂ­ca;Fil: Colombo, Maria Isabel. No especifĂ­ca;Fil: Cuervo, Ana Maria. No especifĂ­ca;Fil: Debnath, Jayanta. No especifĂ­ca;Fil: Deretic, Vojo. No especifĂ­ca;Fil: Dikic, Ivan. No especifĂ­ca;Fil: Dionne, Keith. No especifĂ­ca;Fil: Dong, Xiaonan. No especifĂ­ca;Fil: Elazar, Zvulun. No especifĂ­ca;Fil: Galluzzi, Lorenzo. No especifĂ­ca;Fil: Gentile, Frank. No especifĂ­ca;Fil: Griffin, Diane E.. No especifĂ­ca;Fil: Hansen, Malene. No especifĂ­ca;Fil: Hardwick, J. Marie. No especifĂ­ca;Fil: He, Congcong. No especifĂ­ca;Fil: Huang, Shu Yi. No especifĂ­ca;Fil: Hurley, James. No especifĂ­ca;Fil: Jackson, William T.. No especifĂ­ca;Fil: Jozefiak, Cindy. No especifĂ­ca;Fil: Kitsis, Richard N.. No especifĂ­ca;Fil: Klionsky, Daniel J.. No especifĂ­ca;Fil: Kroemer, Guido. No especifĂ­ca;Fil: Meijer, Alfred J.. No especifĂ­ca;Fil: MelĂ©ndez, Alicia. No especifĂ­ca;Fil: Melino, Gerry. No especifĂ­ca;Fil: Mizushima, Noboru. No especifĂ­ca;Fil: Murphy, Leon O.. No especifĂ­ca;Fil: Nixon, Ralph. No especifĂ­ca;Fil: Orvedahl, Anthony. No especifĂ­ca;Fil: Pattingre, Sophie. No especifĂ­ca;Fil: Piacentini, Mauro. No especifĂ­ca;Fil: Reggiori, Fulvio. No especifĂ­ca;Fil: Ross, Theodora. No especifĂ­ca;Fil: Rubinsztein, David C.. No especifĂ­ca;Fil: Ryan, Kevin. No especifĂ­ca;Fil: Sadoshima, Junichi. No especifĂ­ca;Fil: Schreiber, Stuart L.. No especifĂ­ca;Fil: Scott, Frederick. No especifĂ­ca;Fil: Sebti, Salwa. No especifĂ­ca;Fil: Shiloh, Michael. No especifĂ­ca;Fil: Shoji, Sanae. No especifĂ­ca;Fil: Simonsen, Anne. No especifĂ­ca;Fil: Smith, Haley. No especifĂ­ca;Fil: Sumpter, Kathryn M.. No especifĂ­ca;Fil: Thompson, Craig B.. No especifĂ­ca;Fil: Thorburn, Andrew. No especifĂ­ca;Fil: Thumm, Michael. No especifĂ­ca;Fil: Tooze, Sharon. No especifĂ­ca;Fil: Vaccaro, Maria Ines. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de BioquĂ­mica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquĂ­mica y Medicina Molecular; ArgentinaFil: Virgin, Herbert W.. No especifĂ­ca;Fil: Wang, Fei. No especifĂ­ca;Fil: White, Eileen. No especifĂ­ca;Fil: Xavier, Ramnik J.. No especifĂ­ca;Fil: Yoshimori, Tamotsu. No especifĂ­ca;Fil: Yuan, Junying. No especifĂ­ca;Fil: Yue, Zhenyu. No especifĂ­ca;Fil: Zhong, Qing. No especifĂ­ca
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