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Evasion
Kinds of Evasion Terms modified by Evasion Selected AbstractsCUT-THROAT FRINGE COMPETITION IN AN EMERGING COUNTRY MARKET: TAX EVASION OR THE ABSENCE OF MARKET POWER?,THE JOURNAL OF INDUSTRIAL ECONOMICS, Issue 4 2009ALBERTO SALVO Brazil's established soft-drink firms recently lost ground to multiple low-price entrants, with small-scale operations and minimal advertising. While incumbents attributed such undercutting to entrants' lower costs from non-compliance with the law, ,generics' counterargued that incumbents' high prices stemmed from unilateral market power rather than cost heterogeneity. By estimating a structural model, I can single-handedly explain established brands' high prices through low equilibrium price elasticities of demand. Tax evasion in the fringe, while plausible, appears to be offset by higher procurement costs or less efficient scale. More generally, a competitive informal sector can alleviate the allocative distortions in certain concentrated industries. [source] Evasion of macrophage scavenger receptor A-mediated recognition by pathogenic streptococciEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2008Thomas Areschoug Abstract PRR recognize conserved structures on pathogenic microbes and are important for the defense against invading microorganisms. However, accumulating evidence indicates that many pathogens have evolved mechanisms to avoid recognition by PRR. One type of PRR is the macrophage scavenger receptor A (SR-A), which has been shown to play an important role in recognition and non-opsonic phagocytosis of pathogenic bacteria. The bacterial ligands for SR-A have been suggested to be LPS or lipoteichoic acid. Here, we use murine bone marrow-derived macrophages to analyze the role of SR-A in non-opsonic phagocytosis of two major Gram-positive pathogens, Streptococcus agalactiae (group B streptococcus; GBS) and Streptococcus pyogenes. We show that the polysaccharide capsule of GBS and the surface M protein of S. pyogenes, two important virulence factors, prevent SR-A-mediated non-opsonic phagocytosis of streptococci. The sialic acid moiety of the GBS capsule was crucial for its ability to prevent recognition by SR-A. Moreover, we show that a ligand on GBS recognized by SR-A in the absence of capsule is the surface lipoprotein Blr. These findings represent the first example of a microbial strategy to prevent recognition by SR-A and suggest that bacterial surface proteins may be of importance as ligands for SR-A. [source] The Supreme Court and the Interstate Slave Trade: A Study in Evasion, Anarchy, and ExtremismJOURNAL OF SUPREME COURT HISTORY, Issue 3 2004DAVID L. LIGHTNER Opponents of slavery often argued that the federal government possessed the constitutional authority to outlaw the interstate slave trade. At its founding in 1833, the American Anti-Slavery Society declared that Congress "has a right, and is solemnly bound, to suppress the domestic slave trade between the several States." The idea had been endorsed earlier, during the Missouri controversy of 1819,1820, by both John Jay and Daniel Webster. Later on, in the 1840s and 1850s, it was supported by such prominent politicians as John Quincy Adams, Salmon P. Chase, and Charles Sumner. Defenders of slavery were, of course, horrified by the suggestion that the South's peculiar institution might be attacked in this way, and they vehemently denied that the Constitution permitted any such action. The prolonged debate over the issue focused on two key provisions of the Constitution. One was the Commerce Clause (Article I, Section 8, Clause 3), which says that Congress has the power to "regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes." The other was the 1808 Clause (Article I, Section 9, Clause 1), which says that the "Migration or Importation of such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the Year one thousand eight hundred and eight." Abolitionists held that the Constitution sanctioned congressional interference in the domestic slave trade both generally, by virtue of the Commerce Clause, and specifically, by virtue of the 1808 Clause. They argued that since slaves were routinely bought and sold, they obviously were articles of commerce, and therefore Congress had unlimited authority over interstate slave trafficking. Furthermore, they said, the words "migration or importation" in the 1808 Clause meant that as of January 1, 1808 Congress had acquired the right not only to ban the importation of slaves, but also to prohibit their migration from one state to another. Defenders of slavery replied that Congress could not interfere in property rights and that the power to regulate commerce did not include the power to destroy it. They also said that the word "migration" in the 1808 Clause referred, not to the domestic movement of slaves, but to the entry into the United States of white immigrants from abroad.1 [source] Tax Evasion and Voting: An Experimental AnalysisKYKLOS INTERNATIONAL REVIEW OF SOCIAL SCIENCES, Issue 2 2002Lars P. Feld The authors would like to thank Gerald Hosp and Hannelore Weck-Hannemann for valuable comments and suggestions. The usual disclaimer applies. [source] Immune manipulation of advanced breast cancer: An interpretative model of the relationship between immune system and tumor cell biologyMEDICINAL RESEARCH REVIEWS, Issue 3 2009Andrea Nicolini Abstract This review summarizes some recent clinical immunological approaches with cytokines and/or antibodies for therapy of advanced breast cancer. It considers the recent advances in genetics and molecular tumor biology related to impaired immunosurveillance involving cytokines and growth factors to explain clinical results. Evasion of the host immune attack might be induced by the following groups of mechanisms: (a) tumor dependent (genomic instability, HLA class I antigen abnormalities, upregulation of fetal type nonclassical HLA class I molecules, epitope immunodominance, apoptosis inhibition by defective death receptor signaling, apoptosis of activated T cells, tumor cannibalism and constitutive activation of signal transducer, and activator of transcription-3 (Stat 3) and nuclear factor-,B (NF-kB) signaling); (b) host dependent (CD4+CD25+ regulatory T cells (T reg), CD4+ T cells anergy, Th2 antitumor immunity diversion and myeloid suppressor cells); (c) tumor and host dependent (lack of co-stimulation molecules, immunosuppressive cytokines (vascular endothelial growth factor (VEGF), interleukin (IL)-10, prostaglandin (PG)E2, transforming growth factor (TGF)-,)). Cytokines and growth factors are involved in virtually all three types of mechanisms. These mechanisms are integrated with the current knowledge of tumor growth and inhibited apoptosis primarily mediated by cytokines and growth factors to propose an interpretation of the relationships among tumor cells, tumor stroma, and tumor-infiltrating lymphocytes. Tumor growth, defective immunorecognition and immunosuppression are the three principal effects considered responsible for immune evasion. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 3, 436-471, 2009 [source] A secreted effector protein (SNE1) from Phytophthora infestans is a broadly acting suppressor of programmed cell deathTHE PLANT JOURNAL, Issue 3 2010Brendan S. Kelley Summary Evasion or active suppression of host defenses are critical strategies employed by biotrophic phytopathogens and hemibiotrophs whose infection mechanism includes sequential biotrophic and necrotrophic stages. Although defense suppression by secreted effector proteins has been well studied in bacteria, equivalent systems in fungi and oomycetes are poorly understood. We report the characterization of SNE1 (suppressor of necrosis 1), a gene encoding a secreted protein from the hemibiotrophic oomycete Phytophthora infestans that is specifically expressed at the transcriptional level during biotrophic growth within the host plant tomato (Solanum lycopersicum). Using transient expression assays, we show that SNE1 suppresses the action of secreted cell death-inducing effectors from Phytophthora that are expressed during the necrotrophic growth phase, as well as programmed cell death mediated by a range of Avr,R protein interactions. We also report that SNE1 contains predicted NLS motifs and translocates to the plant nucleus in transient expression studies. A conceptual model is presented in which the sequential coordinated secretion of antagonistic effectors by P. infestans first suppresses, but then induces, host cell death, thereby providing a highly regulated means to control the transition from biotrophy to necrotrophy. [source] Mutational analysis of caspase genes in prostate carcinomasAPMIS, Issue 4 2010MIN SUNG KIM Kim MS, Park SW, Kim YR, Lee JY, Lim HW, Song SY, Yoo NJ, Lee SH. Mutational analysis of caspase genes in prostate carcinomas. APMIS 2010; 118: 308,12. Evasion of apoptosis is one of the hallmarks of cancer. Of the components of apoptosis machinery, caspases are the main executioners of apoptosis that initiate and propagate the apoptosis, and finally degrade target molecules. Caspase-encoding genes have been reported to harbor inactivating mutations in many human cancers. However, mutational status of caspase genes in prostate carcinomas has not been identified. The aim of this study was to explore whether caspase genes are somatically mutated in prostate carcinomas. For this, we analyzed entire coding regions of 11 human caspase-encoding genes (CASP1,10 and 14) in 45 prostate carcinoma tissues by a single-strand conformation polymorphism (SSCP) assay. In this study, however, we detected no somatic mutation of CASP genes in the prostate carcinomas by the SSCP. This is the first report on systematic evaluation of caspase-encoding gene mutations in human prostate carcinomas, and our data indicate that CASP genes may not be mutated in prostate carcinomas. The data suggest that apoptosis evasion in prostate carcinoma may be dependent on other mechanisms besides genetic alteration of caspase-encoding genes. [source] Effort and Aspirations in Tax Evasion: Experimental EvidenceAPPLIED PSYCHOLOGY, Issue 3 2009Erich Kirchler Is the effort exerted to earn taxable income considered in compliance decisions? And if so, is hard-earned income or easy money more likely to be concealed from authorities? While economic theory postulates that prior costs should not affect present decisions, psychological research shows that prior investments of money, time, or effort do matter. Findings from previous studies on the impact of effort on abstract decision tasks suggest two contradictory predictions for the context of tax compliance decisions: Either taxable income earned by high effort is subjectively of higher value, and therefore more likely to be evaded, or investments of effort cause a shift of the reference point through the establishment of an aspiration level, resulting in honest declaration of income. Two experiments were conducted to test these predictions. In a business simulation, taxable income was obtained by different levels of effort and consequently had to be reported to authorities. Results show that tax evasion was more pronounced in low-effort conditions. This suggests that effort changes the reference point rather than the slope, and provides evidence that in tax compliance decisions aspiration levels serve as reference points. Implications for tax audits are discussed. L'effort déployé pour obtenir des revenus imposables est-il pris en compte dans les décisions qui en découlent? Et si c'est le cas, est-ce l'argent facile ou les revenus durement gagnés qui présentent une plus forte probabilité d'être soustraits au fisc? Alors que la théorie économique postule que le coût antérieur n'a pas de retombées sur les décisions présentes, les recherches de psychologie montrent que les investissements passés en argent, temps ou effort ont leur importance. Des travaux sur l'impact de l'effort sur des tâches de décision abstraite débouchent sur deux prédictions contradictoires en ce qui concerne les décisions relatives à l'impôt: ou le revenu imposable obtenu à la suite d'un effort substantiel est subjectivement fortement valorisé et a de fortes chances d'être camouflé, ou l'effort investi provoque un changement de référence à travers l'instauration d'un niveau d'aspiration, ce qui a pour conséquence une déclaration honnête des revenus. On a réalisé deux expériences pour mettre à l'épreuve ces prédictions. Dans une simulation commerciale, le revenu imposable a été obtenu suite à différents niveaux d'effort et devait être portéà la connaissance du fisc. Les résultats montrent que l'évasion fiscale était plus accentuée dans les conditions où l'effort était modeste. Il faut en conclure que l'effort entraîne une mutation du système de référence plutôt qu'une simple modification de niveau et que dans les décisions relatives à l'impôt les niveaux d'aspiration servent de point de référence. On réfléchit aux leçons à en tirer pour le contrôle fiscal. [source] Evasion of innate and adaptive immune responses by influenza A virusCELLULAR MICROBIOLOGY, Issue 7 2010Mirco Schmolke Summary Host organisms have developed sophisticated antiviral responses in order to defeat emerging influenza A viruses (IAVs). At the same time IAVs have evolved immune evasion strategies. The immune system of mammals provides several lines of defence to neutralize invading pathogens or limit their replication. Here, we summarize the mammalian innate and adaptive immune mechanisms involved in host defence against viral infection and review strategies by which IAVs avoid, circumvent or subvert these mechanisms. We highlight well-characterized, as well as recently described features of this intriguing virus-host molecular battle. [source] Modulation of caspases and their non-apoptotic functions by Legionella pneumophilaCELLULAR MICROBIOLOGY, Issue 2 2010Amal O. Amer Summary Legionella pneumophila has become a model system to decipher the non-apoptotic functions of caspases and their role in immunity. In permissive cells, the L. pneumophila -containing vacuole evades endosomal traffic and is remodelled by the endoplasmic reticulum. Evasion of the endosomes is mediated by the Dot/Icm type IV secretion system. Upon L. pneumophila infection of genetically restrictive cells such as wild-type (WT) C57Bl/6J murine macrophages, flagellin is sensed by the NOD-like receptor Nlrc4 leading to caspase-1 activation by the inflammasome complex. Then, caspase-7 is activated downstream of the Nlrc4 inflammasome, promoting non-apoptotic functions such as L. pneumophila -containing phagosome maturation and bacterial degradation. Interestingly, caspase-3 is activated in permissive cells during early stages of infection. However, caspase-3 activation does not lead to apoptosis until late stages of infection because it is associated with potent Dot/Icm-mediated anti-apoptotic stimuli that render the infected cells resistant to external apoptotic inducers. Therefore, the role of caspase-1 and non-apoptotic functions of executioner caspases are temporally and spatially modulated during infection by L. pneumophila, which determine permissiveness to intracellular bacterial proliferation. This review will examine the novel activation pathways of caspases by L. pneumophila and discuss their role in genetic restriction and permissiveness to infection. [source] Gender, Traditional Authority, and the Politics of Rural Reform in South AfricaDEVELOPMENT AND CHANGE, Issue 4 2002Haripriya Rangan The new South African Constitution, together with later policies and legislation, affirm a commitment to gender rights that is incompatible with the formal recognition afforded to unelected traditional authorities. This contradiction is particularly evident in the case of land reform in many rural areas, where women's right of access to land is denied through the practice of customary law. This article illustrates the ways in which these constitutional contradictions play out with particular intensity in the ,former homelands' through the example of a conflict over land use in Buffelspruit, Mpumalanga province. There, a number of women who had been granted informal access to communal land for the purposes of subsistence cultivation had their rights revoked by the traditional authority. Despite desperate protests, they continue to be marginalized in terms of access to land, while their male counterparts appropriate communal land for commercial farming and cattle grazing. Drawing on this protest, we argue that current South African practice in relation to the pressing issue of gender equity in land reform represents a politics of accommodation and evasion that tends to reinforce gender biases in rural development, and in so doing, undermines the prospects for genuinely radical transformation of the instituted geographies and institutionalized practices bequeathed by the apartheid regime. [source] A rare landform: Yerköprü travertine bridges in the Taurids Karst Range, TurkeyEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2002C. Serdar Bayari Abstract Two examples of travertine bridges are observed at 8 to 15 m above stream level in the Lower Zamanti Basin, Eastern Taurids, Turkey. Yerköprü-1 and Yerköprü-2 bridges are currently being deposited from cool karstic groundwaters with log PCO2 > 10,2 atm. The surface area and the total volume of travertine in Yerköprü-1 bridge are 4350 m2 and 40 000 m3, whereas the values for Yerköprü-2 are 2250 m2 and 20 000 m3, respectively. The interplay of hydrogeological structure, local topography, calcite-saturated hanging springs, algal activity and rapid downcutting in the streambed appear to have led to the formation of travertine bridges. Aeration through cascades and algal uptake causes efficient carbon dioxide evasion that enhances travertine formation. Algal curtains aid lateral development of travertine rims across the stream. Model calculations based on a hypothetical deposit in the form of a half-pyramid implied that lateral development should have occurred from both banks of the stream in the Yerköprü-1 bridge, whereas one-sided growth has been sufficient for Yerköprü-2. The height difference between travertine springs and the main stream appears to be a result of Pleistocene glaciation during which karstic base-level lowering was either stopped or slowed down while downcutting in the main stream continued. Copyright © 2002 John Wiley & Sons, Ltd. [source] Tumor expression of CD200 inhibits IL-10 production by tumor-associated myeloid cells and prevents tumor immune evasion of CTL therapyEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2010Lixin Wang Abstract CD200 is a cell-surface glycoprotein that functions through interaction with the CD200 receptor on myeloid lineage cells to regulate myeloid cell functions. Expression of CD200 has been implicated in multiple types of human cancer; however, the impact of tumor expression of CD200 on tumor immunity remains poorly understood. To evaluate this issue, we generated CD200-positive mouse plasmacytoma J558 and mastocytoma P815 cells. We found that established CD200-positive tumors were often completely rejected by adoptively transferred CTL without tumor recurrence; in contrast, CD200-negative tumors were initially rejected by adoptively transferred CTL but the majority of tumors recurred. Tumor expression of CD200 significantly inhibited suppressive activity and IL-10 production by tumor-associated myeloid cells (TAMC), and as a result, more CTL accumulated in the tumor and exhibited a greater capacity to produce IFN-, in CD200-positive tumors than in CD200-negative tumors. Neutralization of IL-10 significantly inhibited the suppressor activity of TAMC, and IL-10-deficiency allowed TAMC to kill cancer cells and their antigenic variants, which prevented tumor recurrence during CTL therapy. Thus, tumor expression of CD200 prevents tumor recurrence via inhibiting IL-10 production by TAMC. [source] Unexpected roles for DEAD-box protein 3 in viral RNA sensing pathwaysEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2010Orla Mulhern Abstract Detection of viral nucleic acid within infected cells is essential to an effective anti-viral response. The retinoic acid-inducible gene-I-like receptors (RLR) form part of the virus detection repertoire and are critically important in sensing viral RNA in the cytoplasm. Efforts continue to define the signalling components downstream of RLR that are required to induce type I IFN (IFN-, and promoter stimulator-1) after viral infection. One surprising finding was that the Asp-Glu-Ala-Asp box helicase DEAD/H Box 3 (DDX3), known for some time to have a number of roles in cellular RNA regulation in the nucleus, has a role in the RLR cytoplasmic signalling pathway involved in promoter stimulator-1 induction. In this issue of the European Journal of Immunology, an article reports an additional distinct positive role for DDX3 in the RLR RNA sensing pathway. This further emphasises the importance of DDX3 in anti-viral immunity, and is consistent with the idea that viruses target DDX3 for immune evasion. [source] Inhibition of CD1d1-mediated antigen presentation by the vaccinia virus B1R and H5R moleculesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2006Roberts Webb, Tonya Abstract Vaccinia virus (VV) has been most commonly used as the vaccine to protect individuals against the causative agent of smallpox (variola virus), but it also uses a number of strategies meant to evade or blunt the host's antiviral immune response. Natural killer T (NKT) cells are a subset of immunoregulatory CD1d-restricted T lymphocytes believed to bridge the innate and adaptive immune responses. It is shown here that the VV-encoded molecules, B1R and H5R, play a role in the ability of VV to inhibit CD1d-mediated antigen presentation to NKT cells. These are the first poxvirus-encoded molecules identified that can play such a role in the evasion of an important component of the innate immune response. [source] The role of genome diversity and immune evasion in persistent infection with Helicobacter pyloriFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2005Cara L. Cooke Abstract Helicobacter pylori is an important human pathogen that chronically colonizes the stomach of half the world's population. Infection typically occurs in childhood and persists for decades, if not for the lifetime of the host. How is bacterial persistence possible despite a vigorous innate and adaptive immune response? Here we describe the complex role of bacterial diversity and specific mechanisms to avoid or subvert host immunity in bacterial persistence. We suggest that H. pylori finely modulates the extent to which it interacts with the host in order to promote chronic infection, and that it uses diverse mechanisms to do so. [source] Ontogeny of escape swimming performance in the spotted salamanderFUNCTIONAL ECOLOGY, Issue 3 2010Tobias Landberg Summary 1.,The life stage suffering the highest predation rate is expected to have the highest escape performance unless developmental or functional constraints interfere. Peak aquatic escape performance in ephemeral pond-breeding amphibians is expected to develop early in the larval period, and metamorphosis is expected to reduce or completely disrupt aquatic escape performance. In anurans, exceptionally low escape performance during metamorphosis creates selection favouring rapid metamorphosis , which minimizes the time individuals spend in the vulnerable transition between tadpole and frog. 2.,We investigated the development of aquatic escape performance in the spotted salamander, Ambystoma maculatum (Shaw, 1802), from embryonic development through metamorphosis. We expected performance to peak early in the larval period as hatchlings face high rates of predation but embryos must first develop escape behaviours. We also tested whether escape performance during metamorphosis was intermediate, as predicted by tail fin resorption, or lower than larvae and adults indicating a major physiological disruption. 3.,Escape performance shows a complex ontogeny that is first positively influenced by embryonic and early larval development and then negatively correlated with tail resorption and body size. Escape distance was the only performance metric not affected by life stage. In contrast, both escape velocity and duration showed ontogenetic peaks early in the larval period with the lowest performance found in early embryos and adults and intermediate performance during metamorphosis. 4.,This pattern suggests that metamorphosis does not impose a major physiological disruption on escape performance. Because spotted salamanders do not pass through a frog-like ,ontogenetic performance valley' during metamorphosis, they may be less subject than anurans to selection favouring rapid metamorphosis. 5.,Functional implications of phenotypic variation should be considered in an ontogenetic framework because the relationship between body size and escape performance can be reversed on either side of an ontogenetic performance peak. The assumption that metamorphosis radically disrupts basic functions such as predator evasion does not seem universally warranted and suggests examination of ontogenetic performance trajectories in a diversity of animals with complex life cycles. [source] Impaired expression and function of toll-like receptor 7 in hepatitis C virus infection in human hepatoma cells,HEPATOLOGY, Issue 1 2010Serena Chang Hepatitis C virus (HCV) interferes with interferon (IFN)-mediated innate immune defenses. Toll-like receptor (TLR) 7 agonists robustly inhibit HCV infection. We hypothesize that HCV infection may interfere with the expression and/or function of TLR7, a sensor of single-stranded RNA. We identified reduced TLR7 RNA and protein levels in hepatoma cells expressing HCV (full-length, BB7-subgenomic, and JFH-1 clone) compared with control HCV-naïve cells. The biological relevance of this finding was confirmed by the observation of decreased TLR7 RNA in livers of HCV-infected patients compared with controls. HCV clearance, by IFN-, treatment or restrictive culture conditions, restored the decreased TLR7 expression. Treatment with RNA polymerase inhibitors revealed a shorter TLR7 half-life in HCV-replicating cells compared with controls. Downstream of TLR7, an increased baseline IRF7 nuclear translocation was observed in HCV-positive cells compared with controls. Stimulation with the TLR7 ligand R837 resulted in significant IRF7 nuclear translocation in control cells. In contrast, HCV-replicating cells showed attenuated TLR7 ligand-induced IRF7 activation. Conclusion: Reduced TLR7 expression, due to RNA instability, directly correlates with HCV replication and alters TLR7-induced IRF7-mediated cell activation. These results suggest a role for TLR7 in HCV-mediated evasion of host immune surveillance. (HEPATOLOGY 2009.) [source] Induction of potent cellular immune response in mice by hepatitis C virus NS3 protein with double-stranded RNAIMMUNOLOGY, Issue 1 2007Bo Jin Summary Double-stranded RNA is produced during virus replication and, together with the viral antigen, is responsible for inducing host antivirus immunity. The hepatitis C virus (HCV) non-structural protein-3 (NS3) has been implicated in the immune evasion of HCV, and is one of the prime targets for inducing immunity against HCV infection. Mice were immunized with recombinant NS3 protein (rNS3) and poly (I:C) emulsified in Montanide ISA 720 (M720). Cytokine production was assayed by enzyme-linked immunospot assay, and CD4+ IFN-,+ T helper (Th) cells or CD8+ IFN-,+ cytotoxic T lymphocytes were detected by flow cytometry. Anti-NS3 titre and immunoglobulin G2a (IgG2a) and IgG1 levels were monitored by enzyme-linked immunosorbent assay. Administration of rNS3 formulated in poly (I:C) and M720 induced anti-NS3 titres with a predominantly IgG2a isotype comparable to those induced by rNS3 in CpG-ODN and M720. The cytokine profiles showed that this formulation induced a Th1-biased immune response with several-fold more interferon-, (IFN-,)-producing cells than interleukin-4-producing cells. In contrast, rNS3 in M720 induced a Th2-biased immune response. The frequency of IFN-,-producing CD4+ and CD8+ cells induced by rNS3 in poly (I:C) and M720 was significantly higher than that induced by rNS3, rNS3 in M720, or rNS3 in poly (I:C), and was comparable to that induced by rNS3 in CpG-ODN with M720. The antigen-specific CD8+ T-cell immune response persisted for up to 7 months after immunization. In conclusion, poly (I:C) with rNS3 in M720 can elicit a strong and persistent Th1-biased immune response and a cytotoxic T-lymphocyte response through cross-priming in mice. This study highlighted a promising formulation for inducing an efficient cellular immune response against HCV that has potential for HCV vaccine development. [source] The MHC class I antigen presentation pathway: strategies for viral immune evasionIMMUNOLOGY, Issue 2 2003Eric W. Hewitt Summary Presumably because of the selective pressure exerted by the immune system, many viruses have evolved proteins that interfere with antigen presentation by major histocompatibility complex (MHC) class I molecules. These viruses utilize a whole variety of ingenious strategies to inhibit the MHC class I pathway. Viral proteins have been characterized that exploit bottlenecks in the MHC class I pathway, such as peptide translocation by the transporter associated with antigen processing. Alternatively, viral proteins can cause the degradation or mislocalization of MHC class I molecules. This is often achieved by the subversion of the host cell's own protein degradation and trafficking pathways. As a consequence elucidation of how these viral proteins act to subvert host cell function will continue to give important insights not only into virus,host interactions but also the function and mechanism of cellular pathways. [source] Apoptosis evasion: The role of survival pathways in prostate cancer progression and therapeutic resistanceJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006Shaun McKenzie Abstract The ability of a tumor cell population to grow exponentially represents an imbalance between cellular proliferation and cellular attrition. There is an overwhelming body of evidence suggesting the ability of tumor cells to avoid programmed cellular attrition, or apoptosis, is a major molecular force driving the progression of human tumors. Apoptotic evasion represents one of the true hallmarks of cancer and appears to be a vital component in the immunogenic, chemotherapeutic, and radiotherapeutic resistance that characterizes the most aggressive of human cancers [Hanahan and Weinberg, 2000]. The challenges in the development of effective treatment modalities for advanced prostate cancer represent a classic paradigm of the functional significance of anti-apoptotic pathways in the development of therapeutic resistance. J. Cell. Biochem. © 2005 Wiley-Liss, Inc. [source] Sequential loss of cell cycle checkpoint control contributes to malignant transformation of murine embryonic fibroblasts induced by 20-methylcholanthreneJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2010Sudeshna Mukherjee Definitive information about the number and nature of discrete steps of tumorigenesis is enigmatic. To understand the multistep nature of carcinogenesis, an in vitro model of 20-Methylcholanthrene-treated primary fibroblast cells CNCI-PM-20, from 20-day old Swiss mouse embryo was used. Visible neoplastic changes with distinct morphological variations along with specific chromosomal aberrations like Robertsonian metacentrics, double and single-minute chromosomes and aneuploidy were observed from Passage-20 onwards. The cell cycle profile showed gradual increase in G2/M population till P-32, followed by evasion of block from P-36 onwards. Gradual increase in expression of C-myc, CyclinD1 and a decrease in expression of P21 was observed from P-20 onwards. CDC25A expression was significantly increased at P-27 and remained more or less constant in subsequent passages. Additionally, an increased P16 and P53 expression were seen at P-20 followed by their significant down-regulation at P-32. An increased level of phosphorylated retinoblastoma (ppRb) was observed from P-27, probably responsible for a compromised G1/S checkpoint. The inactivation of p21 and p16 might be due to their promoter hyper-methylation as suggested through de-methylation experiment by 5-aza-deoxycytidine at P-42. G2/M checkpoint abrogation was marked by gradual increase in expression of CyclinB1 and Cdc20, and a significant increase of Mad2 at P-20. Interestingly, increased expression of phospho-ATM, ATR and phospho-Chk1 were also seen at P-20 followed by their down-regulation at subsequent passages, indicating a perturbation of DNA damage response pathway at early passages. Our findings therefore dramatize the multiple genetic events that can cooperate to promote tumorigenesis. J. Cell. Physiol. 224:49,58, 2010 © 2010 Wiley-Liss, Inc. [source] VOTING, INEQUALITY AND REDISTRIBUTIONJOURNAL OF ECONOMIC SURVEYS, Issue 1 2007Rainald Borck Abstract This paper surveys models of voting on redistribution. Under reasonable assumptions, the baseline model produces an equilibrium with the extent of redistributive taxation chosen by the median income earner. If the median is poorer than average, redistribution is from rich to poor, and increasing inequality increases redistribution. However, under different assumptions about the economic environment, redistribution may not be simply rich to poor, and inequality need not increase redistribution. Several lines of argument are presented, in particular, political participation, public provision of private goods, public pensions, and tax avoidance or evasion. [source] Tax performance: a comparative studyJOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 6 2004Joweria M. Teera This paper seeks to analyse tax performance across countries, utilizing what Musgrave (1969) referred to as the stochastic approach, where tax performance is analysed by comparisons with the average performance. The regression approach to tax performance assessment is used and a tax effort index is constructed. Among the variables that are identified to be important determinants of tax shares is a measure of tax evasion. The tax effort indices obtained show that generally the upper middle-income and high-income OECD groups are making better use of their tax bases to increase revenue. There are also economies of scale with respect to population density. Copyright © 2004 John Wiley & Sons, Ltd. [source] Isolation and functional analysis of five HPVE6 variants with respect to p53 degradationJOURNAL OF MEDICAL VIROLOGY, Issue 3 2008Thomas Hiller Abstract Persistent infection with high risk human papillomavirus is a necessary risk factor in the etiology of invasive cervical carcinoma. With regard to molecular details, the best studied types are HPV16 and HPV18 which are found in 70% of cervical cancer worldwide, however factors associated with the progression of individual cervical intraepithelial neoplasias into cancer are still poorly understood. Intratype amino acid variations in the immortalizing and transforming early proteins E6 and E7 were described to be associated with progressive disease and linked to increased viral persistence or progression. One of the key actions of high risk HPVE6 proteins is the inhibition of the function of p53, a tumor suppressor protein, by enhancing its degradation through the ubiquitin pathway. In this study, variants of five HPV type E6 proteins (HPV35, 53, 56, 66, and 70) isolated from patient materials are described and functional analysis of them were done with respect to p53 degradation. Interestingly the E6 protein of HPV type 53, which has no consistent risk classification in the literature showed the highest variability in our study. The analysis of all variants revealed no differences with regard to the degradation ability for p53 compared to the prototype E6 proteins, suggesting that the variants tested revealed no altered functions related to the carcinogenicity of the respective HPV types. It therefore seems more likely that variations in the E6 gene sequence may allow evasion from the hosts immune system, supporting increased viral persistence. J. Med. Virol. 80:478,483, 2008. © 2008 Wiley-Liss, Inc. [source] Modernization of Tax Administrations and Optimal Fiscal PoliciesJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 6 2009MARTIN BESFAMILLE Since Sandmo (1981), many articles have analyzed optimal fiscal policies in economies with tax evasion. All share a feature: they assume that the cost of enforcing the tax law is exogenous. However, governments often invest resources to reduce these enforcement costs. In a very simple model, we incorporate such investments in the analysis of an optimal fiscal policy. We characterize their optimal level and we show numerically how they interact with the other dimensions of the optimal fiscal policy. Finally, we highlight the differences between our results and those obtained in a model without investment in the tax administration. [source] Under-reporting of Income and Labor Market PerformanceJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 2 2008ANN-SOFIE KOLM To examine the effects on labor market performance of government tax and enforcement policies, this paper develops an equilibrium model featuring tax evasion, matching frictions, and worker,firm wage bargains. In the wage bargains, workers and firms can agree on the amount of remuneration that should not be reported to the tax authorities. We find that increased taxation actually reduces unemployment, whereas more zealous enforcement has the opposite effect. [source] Staphylococcal superantigen-like 5 activates platelets and supports platelet adhesion under flow conditions, which involves glycoprotein Ib, and ,IIb,3JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2009C. J. C. DE HAAS Summary.,Objectives: Staphylococcal superantigen-like 5 (SSL5) is an exoprotein secreted by Staphylococcus aureus that has been shown to inhibit neutrophil rolling over activated endothelial cells via a direct interaction with P-selectin glycoprotein ligand 1 (PSGL-1). Methods and Results: When purified recombinant SSL5 was added to washed platelets in an aggregometry set-up, complete and irreversible aggregation was observed. Proteolysis of the extracellular part of GPIb, or the addition of dRGDW abrogated platelet aggregation. When a mixture of isolated platelets and red cells was perfused over immobilized SSL5 at a shear rate of 300 s,1, stable platelet aggregates were observed, and platelet deposition was substantially reduced after proteolysis of GPIb or after addition of dRGDW. SSL5 was shown to interact with glycocalicin, a soluble GPIb, fragment, and binding of SSL5 to platelets resulted in GPIb-mediated signal transduction as evidenced by translocation of 14-3-3,. In addition, SSL5 was shown to interact with endothelial cell matrix (ECM) and this interaction enhanced aggregation of platelets from whole blood to this ECM. Conclusions: SSL5 activates and aggregates platelets in a GPIb,-dependent manner, which could be important in colonization of the vascular bed and evasion of the immune system by S. aureus. [source] Business Power and Tax Reform: Taxing Income and Profits in Chile and ArgentinaLATIN AMERICAN POLITICS AND SOCIETY, Issue 2 2010Tasha Fairfield ABSTRACT This article examines efforts to increase taxation of highly concentrated, undertapped income and profits in Latin America in the aftermath of structural adjustment. Argentina has advanced further than Chile in two policy areas: corporate taxation, which taps firm-level profits; and tax agency access to bank information, which helps reduce income tax evasion. These outcomes are explained by drawing on the classic concepts of business instrumental power, which entails political actions, and structural power, which arises from investment decisions. In Chile, strong instrumental power removed reforms in both areas from the policy agenda. In Argentina, much weaker instrumental power at the cross-sectoral level facilitated corporate tax increases. Bank information access was expanded after Argentina's 2001 crisis weakened the financial sector's instrumental power and reduced structural power. [source] Tax Amnesties, Justice Perceptions, and Filing Behavior: A Simulation StudyLAW & POLICY, Issue 2 2010SILVIA RECHBERGER A simulation study demonstrates the influence of perceived justice of a tax amnesty on subsequent tax compliance. In addition, it investigates how the amnesty is perceived to serve the punishment objectives retribution (i.e., giving offenders what they "deserve") and value restoration (i.e., restoring the values violated by tax evasion). Hierarchical regression analysis revealed the expected positive influence of justice on subsequent tax compliance. However, when the influence of punishment objectives was controlled for the influence of justice disappeared, while retribution and value restoration showed positive effects on post-amnesty tax compliance. [source] | ||||||||||||||||||||||||||||