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INTRODUCTION: Septic patients undergoing mechanical ventilation (MV) often experience difficulty in weaning. Th aim of this study was to determine whether inflammatory biomarkers of sepsis could be indicative of the failure or success of spontaneous breathing trial (SBT) in these patients. METHODS: Sixty-five patients on MV (42 septic and 23 intubated for other reasons) fulfilling the criteria for SBT were included in the study. Blood samples were collected right before, at the end of (30 min) and 24 h after the SBT. Serum inflammatory mediators associated with sepsis (IL-18, IL-18BP, TNF) were determined and correlated with the outcome of SBT. RESULTS: A successful SBT was achieved in 45 patients (69.2%). Septic patients had a higher percentage of SBT failure as compared to non-septic patients (85% vs. 15%, p = 0.026), with an odds ratio for failing 4.5 times (OR = 4.5 95%CI: 1.16-17.68, p 0.022). IL-18 levels and the relative mRNA expression in serum were significantly higher in septic as compared to non-septic patients (p < 0.05). Sepsis was independently associated with higher serum IL-18 and TNF levels in two time-point GEE models (53-723, p = 0.023 and 0.3-64, p = 0.048, respectively). IL-18BP displayed independent negative association with rapid shallow breathing index (RSBI) (95% CI: -17.6 to -4, p = 0.002). CONCLUSION: Sustained increased levels of IL-18 and IL-18BP, acknowledged markers of sepsis, were found to be indicative of SBT failure in patients recovering from sepsis. Our results show that, although subclinical, remaining septic inflammation that sustaines for a long time complicates the weaning procedure. Biomarkers for the estimation of the septic burden and the right time for weaning are needed.
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INTRODUCTION: Exacerbations are critical events in the course of asthma and chronic obstructive pulmonary disease (COPD). These events are potentially life-threatening, and the studies have shown that they have tremendous implications on long-term disease control and the overall prognosis of the patients. The aim of this study was to examine adipokines, cytokines and C-reactive protein (CRP) as potential biomarkers in asthma and COPD. MATERIAL AND METHODS: Prospective cohort study of COPD and asthma patients treated for acute exacerbations. Thirty-nine COPD patients and 15 asthmatic patients were included in the study. Leptin, adiponectin, resistin, interleukin (Il)-6, 8, 18, tumor necrosis factor-a (TNF-a), and CRP were measured at three time points: on admission, at resolution and at the stable phase. Pre- and post-bronchodilation spirometry was additionally performed at resolution and at the stable phase. RESULTS: In COPD patients, leptin, leptin/adiponectin (L/A) ratio and resistin were elevated on admission compared to the stable phase. In asthmatic patients, leptin levels were raised on admission compared to the stable phase, and adiponectin was elevated at resolution compared to admission. In both diseases, CRP was significantly increased on admission compared to both resolution and stable disease. Finally, TNF-a could distinguish between asthma and COPD stable phase. CONCLUSIONS: Leptin and CRP levels may be useful biomarkers in monitoring COPD and asthma response to treatment during an exacerbation episode. Hypoadiponectinemia was detected in asthma and COPD during all stages of the diseases. TNF-a could distinguish between asthma and COPD stable phase.
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Asma/inmunología , Biomarcadores/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/inmunología , Índice de Severidad de la Enfermedad , Adiponectina/metabolismo , Asma/metabolismo , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Femenino , Humanos , Interleucina-6/metabolismo , Leptina/metabolismo , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
INTRODUCTION: The aim of this study was to assess respiratory health and airway and systemic inflammation in professional forest firefighters post firefighting. METHODS: A total of 60 firefighters who participated in forest firefighting operations in Greece during 2008 were included in the study. A questionnaire consisting of symptoms and exposure, pulmonary function, atopy, bronchial hyperresponsiveness, and markers of inflammation in induced sputum, serum, and bronchoalveolar lavage (BAL) fluid was assessed. RESULTS: A measurable eosinophilic and neutrophilic inflammation was shown to be induced in the bronchial airways after acute exposure during forest firefighting. This was associated with increased respiratory symptoms from the upper and lower respiratory tract and pulmonary function impairment. Additionally, a measurable systemic inflammatory response was demonstrated. This study showed that acute exposure during forest firefighting significantly augments the intensity of airway and systemic inflammation in relation to the baseline inflammatory background due to chronic exposure. CONCLUSION: The repeated acute exposures during firefighting augment the burden of chronic airway and systemic inflammation and may eventually lead to allergic sensitization of the airways and increased incidence of rhinitis and asthma after prolonged exposure.
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AIM: The mammalian lung expresses at least three aquaporin (AQP) water channels whose precise role in lung injury or inflammation is still controversial. MATERIALS AND METHODS: Three murine models of lung inflammation and corresponding controls were used to evaluate the expression of Aqp1, Aqp4, Aqp5 and Aqp9: lipopolysaccharide (LPS)-induced lung injury; HCl-induced lung injury; and ventilation-induced lung injury (VILI). RESULTS: All models yielded increased lung vascular permeability, and inflammatory cell infiltration in the broncho-alveolar lavage fluid; VILI additionally produced altered lung mechanics. Lung expression of Aqp4 decreased in the models that targeted primarily the alveolar epithelium, i.e. acid aspiration and mechanical ventilation, while Aqp5 expression decreased in the model that appeared to target both the capillary endothelium and alveolar epithelium, i.e. LPS. CONCLUSION: Participation of aquaporins in the acute inflammatory process depends on localization and the type of lung injury.
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Lesión Pulmonar Aguda/etiología , Acuaporinas/genética , Regulación de la Expresión Génica , Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/patología , Lesión Pulmonar Aguda/fisiopatología , Animales , Modelos Animales de Enfermedad , Lipopolisacáridos/efectos adversos , Masculino , Ratones , Permeabilidad , ARN Mensajero/genética , ARN Mensajero/metabolismo , Pruebas de Función RespiratoriaRESUMEN
BACKGROUND AND OBJECTIVES: Little data exist on short- and long-term effects of occupational exposure on airway and systemic inflammation in professional firefighters. We aimed to characterize airway and systemic inflammation in training firefighters with a maximum occupational exposure of 1 year compared to the long-term exposure of professional firefighters. METHODS: A questionnaire for symptoms and exposure, pulmonary function, atopy, bronchial hyper-responsiveness, and markers of inflammation in induced sputum, serum, bronchoalveolar lavage (BAL) fluid and bronchial biopsies were assessed in a total of 92 firefighters (63 full-time professionals and 29 trainees). RESULTS: Professional firefighters showed allergic bronchial sensitization documented by the presence of atopy, and eosinophilia in induced sputum, BAL and bronchial biopsies. IL-8, ECP, VEGF, and TNF-α levels were statistically significantly higher in the sputum supernatants of professional firefighters compared to the trainees (p = 0.04, p = 0.02, p = 0.04, and p = 0.02, respectively). Serum IL-8 and TNF-α levels were also statistically significantly higher in the group of professional firefighters (p = 0.04, p = 0.03, respectively). Finally, there was a linear correlation between the duration of the occupation in Service and the degree of airway and systemic inflammation. CONCLUSIONS: These results indicate a "dose-response" effect of chronic exposure to a polluted environment on bronchial and systemic inflammation in professional firefighters.
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Hiperreactividad Bronquial/fisiopatología , Inflamación/patología , Exposición Profesional/efectos adversos , Sistema Respiratorio/patología , Adulto , Hiperreactividad Bronquial/epidemiología , Pruebas de Provocación Bronquial/métodos , Líquido del Lavado Bronquioalveolar/inmunología , Proteína Catiónica del Eosinófilo/metabolismo , Eosinófilos/inmunología , Bomberos , Humanos , Hipersensibilidad/inmunología , Hipersensibilidad/patología , Inflamación/metabolismo , Interleucina-8/sangre , Masculino , Pruebas de Función Respiratoria/métodos , Sistema Respiratorio/fisiopatología , Esputo/inmunología , Síndrome de Respuesta Inflamatoria Sistémica/fisiopatología , Factor de Necrosis Tumoral alfa/sangre , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
PURPOSE: Nanostructured lipid carriers (NLC), nanosized phospholipids/triglyceride particles developed for drug delivery, are considered biologically inactive. We assessed the efficacy of unloaded NLC as experimental treatment for acute lung injury (ALI). METHODS: To induce ALI, C57Black/6 male mice received intratracheal injections of HCl or saline; A single dose of 16 mg/Kg NLC or saline was injected intravenously concomitantly with HCl challenge. NLC uptake mechanisms and effects on endothelial permeability and signaling were studied in cultured endothelial cells and neutrophils. RESULTS: NLC pre-treatment attenuated pulmonary microvascular protein leak, airspace inflammatory cells, thrombin proteolytic activity and histologic lung injury score 24 h post insult. Using fluorescence measurements and flow cytometry in mouse lung microvascular endothelial cell culture homogenates, we determined that NLC rendered fluorescent by curcumin labeling are taken up by endothelial cells from mice expressing caveolin-1, the coat protein of caveolar endocytic vesicles, but not from caveolin-1 gene-disrupted mice, which lack caveolae. In contrast, conventional emulsions (CE), consisting of larger particles, were not incorporated. In addition, NLC pre-treatment of cultured human lung microvascular endothelial cells abrogated thrombin-induced activation of p44/42, albumin permeability response, actin cytoskeletal remodeling and interleukin-6 production. Finally, NLC but not CE abrogated lipopolysaccharide-triggered interleukin-8 release. CONCLUSIONS: NLC are engulfed by endothelial caveolae and possess endothelial-protective effects. These novel properties may be of potential utility in ALI.
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Lesión Pulmonar Aguda/tratamiento farmacológico , Nanoestructuras/uso terapéutico , Fosfolípidos/uso terapéutico , Triglicéridos/uso terapéutico , Lesión Pulmonar Aguda/inmunología , Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/patología , Animales , Coagulación Sanguínea/efectos de los fármacos , Caveolas/inmunología , Caveolas/metabolismo , Caveolas/patología , Caveolina 1/metabolismo , Línea Celular , Citocinas/análisis , Células Endoteliales/efectos de los fármacos , Células Endoteliales/inmunología , Células Endoteliales/metabolismo , Células Endoteliales/patología , Humanos , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Nanoestructuras/análisis , Permeabilidad/efectos de los fármacos , Fosfolípidos/farmacocinética , Trombina/metabolismo , Triglicéridos/farmacocinéticaRESUMEN
INTRODUCTION: Diabetic patients may develop acute lung injury less often than non-diabetics; a fact that could be partially ascribed to the usage of antidiabetic drugs, including metformin. Metformin exhibits pleiotropic properties which make it potentially beneficial against lung injury. We hypothesized that pretreatment with metformin preserves alveolar capillary permeability and, thus, prevents ventilator-induced lung injury. METHODS: Twenty-four rabbits were randomly assigned to pretreatment with metformin (250 mg/Kg body weight/day per os) or no medication for two days. Explanted lungs were perfused at constant flow rate (300 mL/min) and ventilated with injurious (peak airway pressure 23 cmH2O, tidal volume ≈17 mL/Kg) or protective (peak airway pressure 11 cmH2O, tidal volume ≈7 mL/Kg) settings for 1 hour. Alveolar capillary permeability was assessed by ultrafiltration coefficient, total protein concentration in bronchoalveolar lavage fluid (BALF) and angiotensin-converting enzyme (ACE) activity in BALF. RESULTS: High-pressure ventilation of the ex-vivo lung preparation resulted in increased microvascular permeability, edema formation and microhemorrhage compared to protective ventilation. Compared to no medication, pretreatment with metformin was associated with a 2.9-fold reduction in ultrafiltration coefficient, a 2.5-fold reduction in pulmonary edema formation, lower protein concentration in BALF, lower ACE activity in BALF, and fewer histological lesions upon challenge of the lung preparation with injurious ventilation. In contrast, no differences regarding pulmonary artery pressure and BALF total cell number were noted. Administration of metformin did not impact on outcomes of lungs subjected to protective ventilation. CONCLUSIONS: Pretreatment with metformin preserves alveolar capillary permeability and, thus, decreases the severity of ventilator-induced lung injury in this model.
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Metformina/farmacología , Lesión Pulmonar Inducida por Ventilación Mecánica/prevención & control , Animales , Líquido del Lavado Bronquioalveolar/química , Permeabilidad Capilar , Modelos Animales de Enfermedad , Técnicas In Vitro , Masculino , Edema Pulmonar/prevención & control , Conejos , Volumen de Ventilación PulmonarRESUMEN
PURPOSE: To define early kinetics of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and of TREM-1 monocyte gene expression in critically ill patients with sepsis. METHODS: Blood was sampled at regular time intervals from 105 patients with sepsis. Concentrations of tumour necrosis factor α (TNFα), interleukin (IL)-6, IL-8 and IL-10 and IL-12p70 and sTREM-1 were measured by an enzyme immunoassay. Blood mononuclear cells were isolated on day 0 from 20 patients and 10 healthy volunteers; RNA was extracted and gene expression of TREM-1 and TNFα were assessed by reverse transcriptase polymerase chain reaction. RESULTS: Early serum concentrations of sTREM-1 were greater among patients with severe sepsis/shock than among patients with sepsis; those of TNFα, IL-6, IL-8 and IL-10 were pronounced among patients with septic shock. Gene transcripts of TNFα were lower among patients with severe sepsis/shock than among patients with sepsis; that was not the case for TREM-1. Early serum levels of sTREM-1 greater than 180 pg/mL were predictors of shorter duration of mechanical ventilation. CONCLUSIONS: Although serum levels of sTREM-1 are increased early upon advent of severe sepsis/shock, gene expression of TREM-1 on monocytes in severe sepsis/shock is not increased. These findings add considerably to our knowledge on the pathophysiology of sepsis.
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Biomarcadores/sangre , Glicoproteínas de Membrana/sangre , Receptores Inmunológicos/sangre , Sepsis/inmunología , Estudios de Casos y Controles , Citocinas/sangre , Femenino , Perfilación de la Expresión Génica , Humanos , Masculino , Glicoproteínas de Membrana/genética , Persona de Mediana Edad , Monocitos/química , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Receptores Inmunológicos/genética , Sepsis/diagnóstico , Choque Séptico/diagnóstico , Choque Séptico/inmunología , Receptor Activador Expresado en Células Mieloides 1 , Desconexión del VentiladorRESUMEN
Caveolin-1 is a key regulator of pulmonary endothelial barrier function. Here, we tested the hypothesis that caveolin-1 expression is required for ventilator-induced lung injury (VILI). Caveolin-1 gene-disrupted (Cav-1(-/-)) and age-, sex-, and strain-matched wild-type (WT) control mice were ventilated using two protocols: volume-controlled with protective (8 mL/kg) versus injurious (21 mL/Kg) tidal volume for up to 6 hours; and pressure-controlled with protective (airway pressure = 12 cm H(2)O) versus injurious (30 cm H(2)O) ventilation to induce lung injury. Lung microvascular permeability (whole-lung (125)I-albumin accumulation, lung capillary filtration coefficient [K(f, c)]) and inflammatory markers (bronchoalveolar lavage [BAL] cytokine levels and neutrophil counts) were measured. We also evaluated histologic sections from lungs, and the time course of Src kinase activation and caveolin-1 phosphorylation. VILI induced a 1.7-fold increase in lung (125)I-albumin accumulation, fourfold increase in K(f, c), significantly increased levels of cytokines CXCL1 and interleukin-6, and promoted BAL neutrophilia in WT mice. Lung injury by these criteria was significantly reduced in Cav-1(-/-) mice but fully restored by i.v. injection of liposome/Cav-1 cDNA complexes that rescued expression of Cav-1 in lung microvessels. As thrombin is known to play a significant role in mediating stretch-induced vascular injury, we observed in cultured mouse lung microvascular endothelial cells (MLECs) thrombin-induced albumin hyperpermeability and phosphorylation of p44/42 MAP kinase in WT but not in Cav-1(-/-) MLECs. Thus, caveolin-1 expression is required for mechanical stretch-induced lung inflammation and endothelial hyperpermeability in vitro and in vivo.
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INTRODUCTION: Activated Protein C (APC), an endogenous anticoagulant, improves tissue microperfusion and endothelial cell survival in systemic inflammatory states such as sepsis, but intravenous administration may cause severe bleeding. We have thus addressed the role of APC delivered locally by inhalation in preventing acute lung injury from alveolar overdistention and the subsequent ventilator-induced lung injury (VILI). We also assessed the effects of APC on the activation status of Extracellular- Regulated Kinase 1/2 (ERK) pathway, which has been shown to be involved in regulating pulmonary responses to mechanical stretch. METHODS: Inhaled APC (12.5 microg drotrecogin-alpha x 4 doses) or saline was given to tracheotomized C57/Bl6 mice starting 20 min prior to initiation of injurious mechanical ventilation with tidal volume 25 mL/Kg for 4 hours and then hourly thereafter; control groups receiving inhaled saline were ventilated with 8 mL/Kg for 30 min or 4 hr. We measured lung function (respiratory system elastance H), arterial blood gases, surrogates of vascular leak (broncho-alveolar lavage (BAL) total protein and angiotensin-converting enzyme (ACE)-activity), and parameters of inflammation (BAL neutrophils and lung tissue myeloperoxidase (MPO) activity). Morphological alterations induced by mechanical ventilation were examined in hematoxylin-eosin lung tissue sections. The activation status of ERK was probed in lung tissue homogenates by immunoblotting and in paraffin sections by immunohistochemistry. The effect of APC on ERK signaling downstream of the thrombin receptor was tested on A549 human lung epithelial cells by immunoblotting. Statistical analyses were performed using ANOVA with appropriate post-hoc testing. RESULTS: In mice subjected to VILI without APC, we observed hypoxemia, increased respiratory system elastance and inflammation, assessed by BAL neutrophil counts and tissue MPO activity. BAL total protein levels and ACE activity were also elevated by VILI, indicating compromise of the alveolo-capillary barrier. In addition to preserving lung function, inhaled APC prevented endothelial barrier disruption and attenuated hypoxemia and the inflammatory response. Mechanistically, we found a strong activation of ERK in lung tissues by VILI, which was prevented by APC, suggestive of pathogenetic involvement of the Mitogen-Activated Kinase pathway. In cultured human lung epithelial cells challenged by thrombin, APC abrogated the activation of ERK and its downstream effector, cytosolic Phospholipase A2. CONCLUSIONS: Topical application of APC by inhalation may effectively reduce lung injury induced by mechanical ventilation in mice.