933 research outputs found

    Oxidative Stress in Canine Histiocytic Sarcoma Cells Induced by an Infection with Canine Distemper Virus Led to a Dysregulation of HIF-1α Downstream Pathway Resulting in a Reduced Expression of VEGF-B in vitro

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    Histiocytic sarcomas represent malignant tumors which require new treatment strategies. Canine distemper virus (CDV) is a promising candidate due to its oncolytic features reported in a canine histiocytic sarcoma cell line (DH82 cells). Interestingly, the underlying mechanism might include a dysregulation of angiogenesis. Based on these findings, the aim of the present study was to investigate the impact of a persistent CDV-infection on oxidative stress mediated changes in the expression of hypoxia-inducible factor (HIF)-1\u3b1 and its angiogenic downstream pathway in DH82 cells in vitro. Microarray data analysis, immunofluorescence for 8-hydroxyguanosine, superoxide dismutase 2 and catalase, and flow cytometry for oxidative burst displayed an increased oxidative stress in persistently CDV-infected DH82 cells (DH82Ond pi) compared to controls. The HIF-1\u3b1 expression in DH82Ond pi increased, as demonstrated by Western blot, and showed an unexpected, often sub-membranous distribution, as shown by immunofluorescence and immunoelectron microscopy. Furthermore, microarray data analysis and immunofluorescence confirmed a reduced expression of VEGF-B in DH82Ond pi compared to controls. In summary, these results suggest a reduced activation of the HIF-1\u3b1 angiogenic downstream pathway in DH82Ond pi cells in vitro, most likely due to an excessive, unusually localized, and non-functional expression of HIF-1\u3b1 triggered by a CDV-induced increased oxidative stress

    The development of policing in Britain in the next five years.

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    The British police service is currently going through a radical transformation phase. The present Tory-led coalition government has set out an agenda to bring about drastic changes in policing. These proposed changes are unprecedented in the history of policing since 1829. The police service is governed by a tripartite arrangement of checks and balances laid down under the Police Act 1964. By this I mean that there are three key players in relation to police governance in Britain: the Home Secretary, the local police authority and the chief constable. The future of policing in the next five years is set out clearly by the Home Secretary, Theresa May MP, under the Police Reform and Social Responsibility Bill, which is currently being reviewed in the House of Lords. The recent phone hacking scandal has made it imperative for the British public to have a closer look at the police service in relation to proper accountability. There have been references to police corruption as far back as the era of 'parish constables', dating back to 1800, when it was alleged that police officers took bribes, got drunk whilst on duty and lacked moral credibility to protect and serve us (Critchley, 1978). In the seventies and eighties the British public was informed of another scandal involving members of Scotland Yard and criminal gangs in the East End of London. In this article, I shall argue that the issue of police corruption is not a new phenomenon. It is has been an ongoing issue that has haunted the police for over a century. This article is divided into three parts. In the first part of the article I present the following issues: the Metropolitan Police policing plan 2011-2014; the merits and demerits of the policing plan; tripartite police accountability and its shortcomings; democratic accountability and localisation of policing; the professionalisation of policing and the creation of the Police Body; review of police pay and benefits; and the impact of this on police officers' morale. In the second part of my article I present some of the criticisms levelled against the ongoing police reforms. I will look at the criticisms from both internal and external perspectives. By internal criticism, I mean police officers' opposition to the reforms. By external criticism, I mean criticisms from criminologists and members of the British public. In the third part of my article I made my position clear on where I stand in relation to the ongoing police reforms. I shall argue that the current ongoing job cuts in the police service are a disaster waiting to happen, and that our safety has been compromised by politicians. We are now living at the mercy of criminals and law breakers due to manpower shortage. We are all living witnesses to the ongoing public disturbances in Tottenham, Enfield, Brixton, Peckham, Walthamstow and Croydon, in London. The speed of the spread of these riots to other cities like Bristol, Birmingham, Manchester and Liverpool occurred on an unimaginable scale. We all watched how difficult it was for the police to restore order and normality. Rioters looted and plundered goods and burnt down buildings as if no laws existed in our country. A complete breakdown of law and order put the lives of citizens at risk. My article makes a passionate appeal to the present coalition government to rethink the issue of reducing the numbers of police officers protecting us. I shall argue that we need more police officers in Britain not fewer. The level of anger and social discontent is higher than the government ever anticipated, partly because of economic hardship. My argument is that economic hardship is not an excuse to commit burglary, theft, arson, murder and criminal damage with intent to endanger life. Rioters are shameless opportunists, a bunch of hoodlums, criminals who have no place in any civilised society, who should be made to face the due process of law

    Lymphocyte subsets and the role of Th1/Th2 balance in stressed chronic pain patients

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    Background: The complex regional pain syndrome (CRPS) and fibromyalgia (FM) are chronic pain syndromes occurring in highly stressed individuals. Despite the known connection between the nervous system and immune cells, information on distribution of lymphocyte subsets under stress and pain conditions is limited. Methods: We performed a comparative study in 15 patients with CRPS type I, 22 patients with FM and 37 age- and sex-matched healthy controls and investigated the influence of pain and stress on lymphocyte number, subpopulations and the Th1/Th2 cytokine ratio in T lymphocytes. Results: Lymphocyte numbers did not differ between groups. Quantitative analyses of lymphocyte subpopulations showed a significant reduction of cytotoxic CD8+ lymphocytes in both CRPS (p < 0.01) and FM (p < 0.05) patients as compared with healthy controls. Additionally, CRPS patients were characterized by a lower percentage of IL-2-producing T cell subpopulations reflecting a diminished Th1 response in contrast to no changes in the Th2 cytokine profile. Conclusions: Future studies are warranted to answer whether such immunological changes play a pathogenetic role in CRPS and FM or merely reflect the consequences of a pain-induced neurohumoral stress response, and whether they contribute to immunosuppression in stressed chronic pain patients. Copyright (c) 2008 S. Karger AG, Basel

    Antimicrobial Peptides and Skin: A Paradigm of Translational Medicine

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    Antimicrobial peptides (AMPs) are small, cationic, amphiphilic peptides with broad-spectrum microbicidal activity against both bacteria and fungi. In mammals, AMPs form the first line of host defense against infections and generally play an important role as effector agents of the innate immune system. The AMP era was born more than 6 decades ago when the first cationic cyclic peptide antibiotics, namely polymyxins and tyrothricin, found their way into clinical use. Due to the good clinical experience in the treatment of, for example, infections of mucus membranes as well as the subsequent understanding of mode of action, AMPs are now considered for treatment of inflammatory skin diseases and for improving healing of infected wounds. Based on the preclinical findings, including pathobiochemistry and molecular medicine, targeted therapy strategies are developed and first results indicate that AMPs influence processes of diseased skin. Importantly, in contrast to other antibiotics, AMPs do not seem to propagate the development of antibiotic-resistant micro-organisms. Therefore, AMPs should be tested in clinical trials for their efficacy and tolerability in inflammatory skin diseases and chronic wounds. Apart from possible fields of application, these peptides appear suited as an example of the paradigm of translational medicine for skin diseases which is today seen as a `two-way road' - from bench to bedside and backwards from bedside to bench. Copyright (c) 2012 S. Karger AG, Base

    Structural remodeling and oligomerization of human cathelicidin on membranes suggest fibril-like structures as active species

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    Antimicrobial peptides as part of the mammalian innate immune system target and remove major bacterial pathogens, often through irreversible damage of their cellular membranes. To explore the mechanism by which the important cathelicidin peptide LL-37 of the human innate immune system interacts with membranes, we performed biochemical, biophysical and structural studies. The crystal structure of LL-37 displays dimers of anti-parallel helices and the formation of amphipathic surfaces. Peptide-detergent interactions introduce remodeling of this structure after occupation of defined hydrophobic sites at the dimer interface. Furthermore, hydrophobic nests are shaped between dimer structures providing another scaffold enclosing detergents. Both scaffolds underline the potential of LL-37 to form defined peptide-lipid complexes in vivo. After adopting the activated peptide conformation LL-37 can polymerize and selectively extract bacterial lipids whereby the membrane is destabilized. The supramolecular fibril-like architectures formed in crystals can be reproduced in a peptide-lipid system after nanogold-labelled LL-37 interacted with lipid vesicles as followed by electron microscopy. We suggest that these supramolecular structures represent the LL-37-membrane active state. Collectively, our study provides new insights into the fascinating plasticity of LL-37 demonstrated at atomic resolution and opens the venue for LL-37-based molecules as novel antibiotics.We would like to thank Sandra Delgado for the technical help in the preparation of the cryoEM vitrified grids and Dr. Isabel Uson and Dr. Ivan De Marino for the Arcimboldo software and valuable help. Funding was provided by the Unidad de Biofisica and the IKERBASQUE and MINECO science foundations

    Modelling study of dimerization in mammalian defensins

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    BACKGROUND: Defensins are antimicrobial peptides of innate immunity functioning by non-specific binding to anionic phospholipids in bacterial membranes. Their cationicity, amphipathicity and ability to oligomerize are considered key factors for their action. Based on structural information on human β-defensin 2, we examine homologous defensins from various mammalian species for conserved functional physico-chemical characteristics. RESULTS: Based on homology greater than 40%, structural models of 8 homologs of HBD-2 were constructed. A conserved pattern of electrostatics and dynamics was observed across 6 of the examined defensins; models backed by energetics suggest that the defensins in these 6 organisms are characterized by dimerization-linked enhanced functional potentials. In contrast, dimerization is not energetically favoured in the sheep, goat and mouse defensins, suggesting that they function efficiently as monomers. CONCLUSION: β-defensin 2 from some mammals may work as monomers while those in others, including humans, work as oligomers. This could potentially be used to design human defensins that may be effective at lower concentrations and hence have therapeutic benefits

    Inducible ASABF-Type Antimicrobial Peptide from the Sponge Suberites domuncula: Microbicidal and Hemolytic Activity in Vitro and Toxic Effect on Molluscs in Vivo†

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    Since sponges, as typical filter-feeders, are exposed to a high load of attacking prokaryotic and eukaryotic organisms, they are armed with a wide arsenal of antimicrobial/cytostatic low-molecular-weight, non-proteinaceous bioactive compounds. Here we present the first sponge agent belonging to the group of ASABF-type antimicrobial peptides. The ASABF gene was identified and cloned from the demosponge Suberites domuncula. The mature peptide, with a length of 64 aa residues has a predicted pI of 9.24, and comprises the characteristic CSα β structural motif. Consequently, the S. domuncula ASABF shares high similarity with the nematode ASABFs; it is distantly related to the defensins. The recombinant peptide was found to display besides microbicidal activity, anti-fungal activity. In addition, the peptide lyses human erythrocytes. The expression of ASABF is upregulated after exposure to the apoptosis-inducing agent 2,2′-dipyridyl. During the process of apoptosis of surface tissue of S. domuncula, grazing gastropods (Bittium sp.) are attracted by quinolinic acid which is synthesized through the kynurenine pathway by the enzyme 3-hydroxyanthranilate 3,4-dioxygenase (HAD). Finally, the gastropods are repelled from the sponge tissue by the ASABF. It is shown that the effector peptide ASABF is sequentially expressed after the induction of the HAD gene and a caspase, as a central enzyme executing apoptosis

    Influence of oral beclomethasone dipropionate on early non-infectious pulmonary outcomes after allogeneic hematopoietic cell transplantation: results from two randomized trials.

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    Early non-infectious pulmonary complications represent a significant cause of mortality after hematopoietic cell transplantation (HCT). We tested the hypothesis that oral beclomethasone dipropionate (BDP) is effective for preventing early non-infectious pulmonary complications after allogeneic HCT. We retrospectively reviewed the medical records of 120 patients, 60 in each treatment arm, to identify non-infectious and infectious pulmonary events and pulmonary function test results from all patients who participated in two randomized trials of oral BDP for treatment of acute gastrointestinal GVHD. 17-Beclomethasone monopropionate (17-BMP), the active metabolite of BDP, was evaluated in blood from the right atrium in four patients. Thirty-three of 42 (79%) placebo-treated patients experienced a decrease of the DL(CO) from pretransplant to day 80 after transplant, compared with 27 of 49 (55%) BDP-treated patients (P=0.02). In the first 200 days after randomization, there were no cases of non-infectious pulmonary complications in BDP-treated patients, vs four cases among placebo-treated patients (P=0.04). Levels of 17-BMP were detected in atrial blood at steady state. Delivery of a potent glucocorticoid such as 17-BMP to the pulmonary artery after oral dosing of BDP may be useful in modulating pulmonary inflammation and preventing the development of non-infectious pulmonary complications after allogeneic HCT.Bone Marrow Transplantation advance online publication, 29 June 2009; doi:10.1038/bmt.2009.129
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