337 research outputs found

    Molecular mechanisms of NET formation and degradation revealed by intravital imaging in the liver vasculature

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    Neutrophil extracellular traps (NETs) composed of DNA decorated with histones and proteases trap and kill bacteria but also injure host tissue. Here we show that during a bloodstream infection with methicillin-resistant Staphylococcus aureus, the majority of bacteria are sequestered immediately by hepatic Kupffer cells, resulting in transient increases in liver enzymes, focal ischaemic areas and a robust neutrophil infiltration into the liver. The neutrophils release NETs into the liver vasculature, which remain anchored to the vascular wall via von Willebrand factor and reveal significant neutrophil elastase (NE) proteolytic activity. Importantly, DNase although very effective at DNA removal, and somewhat effective at inhibiting NE proteolytic activity, fails to remove the majority of histones from the vessel wall and only partly reduces injury. By contrast, inhibition of NET production as modelled by PAD4-deficiency, or prevention of NET formation and proteolytic activity as modelled in NE(−/−) mice prevent collateral host tissue damage

    Invariant natural killer T cells act as an extravascular cytotoxic barrier for joint-invading Lyme Borrelia

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    SignificanceInvariant natural killer T cells (iNKT) have been found primarily patrolling inside blood vessels in the liver, where they respond to bacterial glycolipids presented by CD1d on liver macrophages. We show joint iNKT cells are localized outside of blood vessels and respond directly to the joint-homing pathogen, Borrelia burgdorferi, which causes Lyme borreliosis using multichannel spinning-disk intravital microscopy. These iNKT cells interacted with B. burgdorferi at the vessel wall and disrupted its dissemination attempts into joints. Successful penetrance of B. burgdorferi out of the vasculature and into the joint tissue was met by a lethal attack by extravascular iNKT cells through a granzyme-dependent pathway. These results suggest a critical extravascular iNKT cell immune surveillance in joints that functions as a cytotoxic barrier

    Candesartan Attenuates Diabetic Retinal Vascular Pathology by Restoring Glyoxalase-I Function

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    This is an uncopyedited electronic version of an article accepted for publication in Diabetes. The American Diabetes Association, publisher of Diabetes, is not responsible for any errors or omissions in this version of the manuscript or any version derived from it by third parties. The definitive publisher-authenticated version will be available in a future issue of Diabetes in print and online a

    In vivo and in vitro proinflammatory effects of particulate air pollution (PM10).

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    Epidemiologic studies have reported associations between fine particulate air pollution, especially particles less than 10 mm in diameter (PM10), and the development of exacerbations of asthma and chronic obstructive pulmonary disease. However, the mechanism is unknown. We tested our hypothesis that PM10 induces oxidant stress, causing inflammation and injury to airway epithelium. We assessed the effects of intratracheal instillation of PM10 in rat lungs. The influx of inflammatory cells was measured in bronchoalveolar lavage (BAL). Airspace epithelial permeability was assessed as total protein in bronchoalveolar lavage fluid (BALF) in vivo. The oxidant properties of PM10 were determined by their ability to cause changes in reduced glutathione (GSH) and oxidized glutathione (GSSG). We also compared the effects of PM10 with those of fine (CB) and ultrafine (ufCB) carbon black particles. Six hours after intratracheal instillation of PM10, we noted an influx of neutrophils (up to 15% of total BAL cells) in the alveolar space, increased epithelial permeability, an increase in total protein in BALF from 0.39 +/- 0.01 to 0.62 +/- 0.01 mg/ml (mean +/- SEM) and increased lactate dehydrogenase concentrations in BALF. An even greater inflammatory response was observed after intratracheal instillation of ufCB, but not after CB instillation. PM10 had oxidant activity in vivo, as shown by decreased GSH in BALF (from 0.36 +/- 0.05 to 0.25 +/- 0.01 nmol/ml) after instillation. BAL leukocytes from rats treated with PM10 produced greater amounts of nitric oxide, measured as nitrite (control 3.07 +/- 0.33, treated 4.45 +/- 0.23 mM/1 x 10(6) cells) and tumor necrosis factor alpha (control 21.0 +/- 3.1, treated 179.2 +/- 29.4 unit/1 x 10(6) cells) in culture than BAL leukocytes obtained from control animals. These studies provide evidence that PM10 has free radical activity and causes lung inflammation and epithelial injury. These data support our hypothesis concerning the mechanism for the adverse effects of particulate air pollution on patients with airway diseases

    Current practice in proton therapy delivery in adult cancer patients across Europe

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    BACKGROUND AND PURPOSE Major differences exist among proton therapy (PT) centres regarding PT delivery in adult cancer patient. To obtain insight into current practice in Europe, we performed a survey among European PT centres. MATERIALS AND METHODS We designed electronic questionnaires for eight tumour sites, focusing on four main topics: 1) indications and patient selection methods; 2) reimbursement; 3) on-going or planned studies, 4) annual number of patients treated with PT. RESULTS Of 22 centres, 19 (86%) responded. In total, 4233 adult patients are currently treated across Europe annually, of which 46% consists of patients with central nervous system tumours (CNS), 15% head and neck cancer (HNC), 15% prostate, 9% breast, 5% lung, 5% gastrointestinal, 4% lymphoma, 0.3% gynaecological cancers. CNS are treated in all participating centres (n = 19) using PT, HNC in 16 centres, lymphoma in 10 centres, gastrointestinal in 10 centres, breast in 7 centres, prostate in 6 centres, lung in 6 centres, and gynaecological cancers in 3 centres. Reimbursement is provided by national health care systems for the majority of commonly treated tumour sites. Approximately 74% of centres enrol patients for prospective data registration programs. Phase II-III trials are less frequent, due to reimbursement and funding problems. Reasons for not treating certain tumour types with PT are lack of evidence (30%), reimbursement issues (29%) and/or technical limitations (20%). CONCLUSION Across European PT centres, CNS tumours and HNC are the most frequently treated tumour types. Most centres use indication protocols. Lack of evidence for PT and reimbursement issues are the most reported reasons for not treating specific tumour types with PT

    The Mast Cell Degranulator Compound 48/80 Directly Activates Neurons

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    Background Compound 48/80 is widely used in animal and tissue models as a “selective” mast cell activator. With this study we demonstrate that compound 48/80 also directly activates enteric neurons and visceral afferents. Methodology/Principal Findings We used in vivo recordings from extrinsic intestinal afferents together with Ca++ imaging from primary cultures of DRG and nodose neurons. Enteric neuronal activation was examined by Ca++ and voltage sensitive dye imaging in isolated gut preparations and primary cultures of enteric neurons. Intraluminal application of compound 48/80 evoked marked afferent firing which desensitized on subsequent administration. In egg albumen-sensitized animals, intraluminal antigen evoked a similar pattern of afferent activation which also desensitized on subsequent exposure to antigen. In cross-desensitization experiments prior administration of compound 48/80 failed to influence the mast cell mediated response. Application of 1 and 10 µg/ml compound 48/80 evoked spike discharge and Ca++ transients in enteric neurons. The same nerve activating effect was observed in primary cultures of DRG and nodose ganglion cells. Enteric neuron cultures were devoid of mast cells confirmed by negative staining for c-kit or toluidine blue. In addition, in cultured enteric neurons the excitatory action of compound 48/80 was preserved in the presence of histamine H1 and H2 antagonists. The mast cell stabilizer cromolyn attenuated compound 48/80 and nicotine evoked Ca++ transients in mast cell-free enteric neuron cultures. Conclusions/Significance The results showed direct excitatory action of compound 48/80 on enteric neurons and visceral afferents. Therefore, functional changes measured in tissue or animal models may involve a mast cell independent effect of compound 48/80 and cromolyn

    Getting the invite list right : a discussion of sepsis severity scoring systems in severe complicated intra-abdominal sepsis and randomized trial inclusion criteria

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    Background: Severe complicated intra-abdominal sepsis (SCIAS) is a worldwide challenge with increasing incidence. Open abdomen management with enhanced clearance of fluid and biomediators from the peritoneum is a potential therapy requiring prospective evaluation. Given the complexity of powering multi-center trials, it is essential to recruit an inception cohort sick enough to benefit from the intervention; otherwise, no effect of a potentially beneficial therapy may be apparent An evaluation of abilities of recognized predictive systems to recognize SCIAS patients was conducted using an existing intra-abdominal sepsis (IAS) database. Methods: All consecutive adult patients with a diffuse secondary peritonitis between 2012 and 2013 were collected from a quaternary care hospital in Finland, excluding appendicitis/cholecystitis. From this retrospectively collected database, a target population (93) of those with either ICU admission or mortality were selected. The performance metrics of the Third Consensus Definitions for Sepsis and Septic Shock based on both SOFA and quick SOFA, the World Society of Emergency Surgery Sepsis Severity Score (WSESSSS), the APACHE II score, Manheim Peritonitis Index (MPI), and the Calgary Predisposition, Infection, Response, and Organ dysfunction (CPIRO) score were all tested for their discriminant ability to identify this subgroup with SCIAS and to predict mortality. Results: Predictive systems with an area under-the-receiving-operating characteristic (AUQ curve >= 0.8 included SOFA, Sepsis-3 definitions, APACHE II, WSESSSS, and CPIRO scores with the overall best for CPIRO. The highest identification rates were SOFA score >= 2 (78.4%), followed by the WSESSSS score >= 8 (73.1%), SOFA >= 3 (752%), and APACHE II >= 14 (68.8%) identification. Combining the Sepsis-3 septic-shock definition and WSESSS >= 8 increased detection to 80%. Including CPIRO score >= 3 increased this to 82.8% (Sensitivity-SN; 83% Specificity-SP; 74%. Comparatively, SOFA >= 4 and WSESSSS >= 8 with or without septic-shock had 83.9% detection (SN; 84%, SP; 75%, 25% mortality). Conclusions: No one scoring system behaves perfectly, and all are largely dominated by organ dysfunction. Utilizing combinations of SOFA, CPIRO, and WSESSSS scores in addition to the Sepsis-3 septic shock definition appears to offer the widest "inclusion-criteria" to recognize patients with a high chance of mortality and ICU admission.Peer reviewe
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