951 resultados para AIRWAY REACTIVITY


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AIM: Patients with non-insulin-dependent diabetes mellitus (NIDDM) are at increased cardiovascular risk due to an accelerated atherosclerotic process. The present study aimed to compare skin microvascular function, pulse wave velocity (PWV), and a variety of hemostatic markers of endothelium injury [von Willebrand factor (vWF), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), tissue factor pathway inhibitor (TFPI), and the soluble form of thrombomodulin (s-TM)] in patients with NIDDM. METHODS: 54 patients with NIDDM and 38 sex- and age-matched controls were studied. 27 diabetics had no overt micro- and/or macrovascular complications, while the remainder had either or both. The forearm skin blood flow was assessed by laser-Doppler imaging, which allowed the measurement of the response to iontophoretically applied acetylcholine (endothelium-dependent vasodilation) and sodium nitroprusside (endothelium-independent vasodilation), as well as the reactive hyperemia triggered by the transient occlusion of the circulation. RESULTS: Both endothelial and non-endothelial reactivity were significantly blunted in diabetics, regardless of the presence or the absence of vascular complications. Plasma vWF, TFPI and s-TM levels were significantly increased compared with controls only in patients exhibiting vascular complications. Concentrations of t-PA and PAI-1 were significantly increased in the two groups of diabetics versus controls. CONCLUSION: In NIDDM, both endothelium-dependent and -independent microvascular skin reactivity are impaired, whether or not underlying vascular complications exist. It also appears that microvascular endothelial dysfunction is not necessarily associated in NIDDM with increased circulating levels of hemostatic markers of endothelial damage known to reflect a hypercoagulable state.

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The aim of T cell vaccines is the expansion of antigen-specific T cells able to confer immune protection against pathogens or tumors. Although increase in absolute cell numbers, effector functions and TCR repertoire of vaccine-induced T cells are often evaluated, their reactivity for the cognate antigen versus their cross-reactive potential is rarely considered. In fact, little information is available regarding the influence of vaccines on T cell fine specificity of antigen recognition despite the impact that this feature may have in protective immunity. To shed light on the cross-reactive potential of vaccine-induced cells, we analyzed the reactivity of CD8(+) T cells following vaccination of HLA-A2(+) melanoma patients with Melan-A peptide, incomplete Freund's adjuvant and CpG-oligodeoxynucleotide adjuvant, which was shown to induce strong expansion of Melan-A-reactive CD8(+) T cells in vivo. A collection of predicted Melan-A cross-reactive peptides, identified from a combinatorial peptide library, was used to probe functional antigen recognition of PBMC ex vivo and Melan-A-reactive CD8(+) T cell clones. While Melan-A-reactive CD8(+) T cells prior to vaccination are usually constituted of widely cross-reactive naive cells, we show that peptide vaccination resulted in expansion of memory T cells displaying a reactivity predominantly restricted to the antigen of interest. Importantly, these cells are tumor-reactive.

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PATIENTS: All neonates admitted between January 2002 and December 2007 treated by nCPAP were eligible. METHODS: Patients' noses were monitored during nCPAP. Nasal trauma was reported into three stages: (I) persistent erythema; (II) superficial ulceration; and (III) necrosis. RESULTS: 989 neonates were enrolled. Mean gestational age was 34 weeks (SD 4), mean birth weight 2142 g (SD 840). Nasal trauma was reported in 420 (42.5%) patients and it was of stage I, II and III in 371 (88.3%), 46 (11%) and 3 (0.7%) patients, respectively. Incidence and severity of trauma were inversely correlated with gestational age and birth weight. The risk of nasal trauma was greater in neonates <32 weeks of gestational age (OR 2.48, 95% CI 1.59 to 3.86), weighing <1500 g at birth (OR 2.28, 95% CI 1.43 to 3.64), treated >5 days by nCPAP (OR 5.36, 95% CI 3.82 to 7.52), or staying >14 days in the NICU (OR 1.67, 95% CI 1.22 to 2.28). Most cases of nasal trauma (90%) appeared during the first 6 days of nCPAP. Persistent visible scars were present in two cases. CONCLUSIONS: Nasal trauma is a frequent complication of nCPAP, especially in preterm neonates, but long-term cosmetic sequelae are very rare. This study provides a description of nasal trauma and proposes a simple staging system. This could serve as a basis to develop strategies of prevention and treatment of this iatrogenic event.

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A set of connections among several nuclear and electronic indexes of reactivity in the framework of the conceptual Density Functional Theory by using an expansion ofthe energy functional in terms of the total number of electrons and the normal coordinates within a canonical ensemble was derived. The relations obtained provided explicit links between important quantities related to the chemical reactivity of a system. This paper particularly demonstrates that the derivative of the electronic energy with respect to the external potential of a system in its equilibrium geometry was equal to the negative of the nuclear repulsion derivative with respect to the external potential

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BACKGROUND: Food allergy has reached an epidemic level in westernized countries and although central mechanisms have been described, the variability associated with genetic diversity underscores the still unresolved complexity of these disorders. OBJECTIVE: To develop models of food allergy and oral tolerance, both strictly induced by the intestinal route, and to compare antigen-specific responses. METHODS: BALB/c mice were mucosally sensitized to ovalbumin (OVA) in the presence of the mucosal adjuvant cholera toxin, or tolerized by intra-gastric administrations of OVA alone. Antibody titres and cytokines were determined by ELISA, and allergic status was determined through several physiologic parameters including decline in temperature, diarrhoea, mast cell degranulation and intestinal permeability. RESULTS: OVA-specific antibodies (IgE, IgGs and IgA in serum and feces) were produced in sensitized mice exclusively. Upon intra-gastric challenge with OVA, sensitized mice developed anaphylactic reactions associated with a decline of temperature, diarrhoea, degranulation of mast cells, which were only moderately recruited in the small intestine, and increased intestinal permeability. Cytokines produced by immune cells from sensitized mice included T-helper type 2 cytokines (IL-5, IL-13), but also IL-10, IFN-gamma and IL-17. In contrast, all markers of allergy were totally absent in tolerized animals, and yet the latter were protected from subsequent sensitization, demonstrating that oral tolerance took place efficiently. CONCLUSION: This work allows for the first time an appropriate comparison between sensitized and tolerized BALB/c mice towards OVA. It highlights important differences from other models of allergy, and thus questions some of the generally accepted notions of allergic reactions, such as the protective role of IFN-gamma, the importance of antigen-specific secretory IgA and the role of mucosal mast cells in intestinal anaphylaxis. In addition, it suggests that IL-17 might be an effector cytokine in food allergy. Finally, it demonstrates that intestinal permeability towards the allergen is increased during challenge.

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RESUME La ventilation en pression positive continue (Continuous Positive Airway Pressure, CPAP), utilisée pour la première fois chez. les prématurés en 1971, est une technique actuellement très largement utilisée dans les unités néonatales. L'utilisation de la CPAP présente de nombreux avantages à court terme: diminution de la fraction maximale inspirée d'oxygène, de la durée de l'oxygénothérapie, du taux d'intubation et donc du recours à une ventilation mécanique, réduction de l'utilisation des amines, des curares et de la morphine, possible prévention de l'apparition d'une bronchodysplasie pulmonaire, et possibles réductions du nombre d'infections postnatales et des entérocolites nécrosantes. Mais peu d'études existent concernant les effets à long terme de la CPAP sur le neurodéveloppement et la croissance, qui constituent l'objectif de la présente étude. L'utilisation systématique de la CPAP comme alternative à la ventilation mécanique a été introduite à Lausanne en 1998. La population cible de cette étude est constituée des prématurés nés à moins de 32 semaines de gestation ou pesant moins de 1500 g à la naissance; ils ont été systématiquement suivis jusqu'en âge préscolaire dans le cadre de l'étude de cohorte «Unité de Développement, CHUV». L'originalité de ce travail réside dans le fait d'évaluer le neurodéveloppement et la croissance à long terme d'enfants prématurés traités préférentiellement avec la CPAP, en comparaison avec un groupe historique contrôle traité par d'autres modes ventilatoires, en tenant compte de nombreux autres paramètres néonataux. Du point de vue du neurodéveloppement, l'usage, de la CPAP montre une tendance à diminuer l'incidence d'hémorragie intraventriculaire et le risque d'avoir un mauvais neurodéveloppement à 6 mois. Ces résultats positifs sur le neurodéveloppement s'estompent à l'âge de 18 mois, où persiste néanmoins une valeur plus élevée du quotient de développement, et disparaissent complètement en âge préscolaire. Du point de vue de la croissance, l'utilisation de la CPAP ne montre aucun effet sur le poids, mais par contre un effet positif sur la taille à 6 et 18 mois et sur le périmètre crânien à 6 mois, 18 mois et en âge préscolaire. Malgré le caractère non randomisé de cette étude, les résultats positifs obtenus ici permettent sans conteste de s'assurer d'une utilisation de la CPAP sans effet négatif sur le neurodéveloppement et la croissance, et fournissent donc un argument supplémentaire pour l'utilisation systématique de la CPAP chez les prématurés.

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ABSTRACT Allergic asthma is a major complication of atopy. Its severity correlates with the presence of activated T lymphocytes and eosinophils in the bronchoalveolar lavage fluid (BALF). Mechanisms that protect against asthma are poorly understood. Based on oral models of mucosal tolerance induction, models using the nasal route showed that uptake of important amounts of antigen can induce tolerance and reverse the allergic phenotype. 1L-10 producing regulatory T cells were proposed as key players in tolerance induction, but other players, e.g. dendritic cells (DC), B cells and epithelial cells may have to be taken into consideration. The objective of the present study is to characterize the effects of a therapeutic intranasal treatment (INT) in a murine model of asthma and to determine, in this model, the cellular and molecular mechanisms leading to protection against asthma. First, we established an asthma model by sensitizing the BALB/c mouse to ovalbumin (OVA) by two intraperitoneal injections of alum-adsorbed OVA and three inhalations of aerosolized OVA. Then OVA was applied to the nasal mucosa of OVA- sensitized mice. Mice were later re-exposed to OVA aerosols to assess the protection induced by OVA INT. OVA sensitization induced strong eosinophil recruitment, OVA-specific T cell proliferation and IgE production. Three intranasal treatments at 24-hour intervals with 1.5 mg OVA drastically reduced inflammatory cell recruitment into the BALF and inhibited OVA-specific IgE production upon allergen re-exposure. T cell proliferation in ex vivo bronchial lymph node (BLN) cells was inhibited, as well as TH2 cytokine production. Protection against OVA-induced bronchial inflammation was effective for an extended period of time and treated mice resisted a second re-exposure. Transfer of CD4+ cells from BLN and lungs of OVA-treated mice protected asthmatic recipient mice from subsequent aerosol challenge indicating an involvement of CD4+ T regulatory cells in this protection. RESUME L'asthme allergique est une manifestation clinique majeure de l'atopie. La sévérité de l'asthme est liée à la présence de lymphocytes T activés ainsi que d'éosinophiles dans le lavage broncho-alvéolaire (LBA). Les mécanismes permettant de se prémunir contre l'asthme sont mal connus. Basés sur des modèles muqueux d'induction de tolérance par la voie orale, des modèles utilisant la voie nasale ont montré que d'importantes quantités d'antigène peuvent induire une tolérance et ainsi reverser le phénotype allergique. Des cellules régulatrices produisant de l'IL-10 pourraient jouer un rôle clé dans l'induction de la tolérance mais d'autres acteurs tels que les cellules dendritiques, les cellules B et les cellules épithéliales doivent aussi être prises en compte. L'objectif de la présente étude est de caractériser les effets d'un traitement intranasal thérapeutique dans un modèle murin d'asthme et de déterminer dans ce modèle les mécanismes cellulaires et moléculaires conférant une protection contre l'asthme. En premier lieu, un modèle d'asthme allergique a été établi en sensibilisant des souris BALB/c à l'ovalbumine (OVA) par deux injections intraperitonéales d'OVA adsorbé sur de l'alum et trois séances d'OVA en aérosol. Dans un second temps, de l'OVA a été administrée sur la muqueuse nasale des souris sensibilisées à l'OVA. Les souris furent ensuite challengées par des aérosols d'OVA afin d'évaluer la protection conférée par le traitement intranasal à l'OVA. La sensibilisation à l'OVA a induit un fort recrutement d'éosinophiles, une réponse proliférative des cellules T à l'OVA ainsi qu'une production d'lgE spécifiques. Trois traitements intranasaux à 24 heures d'intervalle avec 1.5 mg d'OVA ont permis de réduire drastiquement le recrutement des cellules inflammatoires dans le LBA ainsi que d'inhiber la production d'lgE spécifiques à l'OVA produits lors d'une ré-exposition à l'OVA. La prolifération en réponse à l'OVA de cellules extraites ex vivo de ganglions bronchiques a, elle aussi, été inhibée de même que la production de cytokines TH2. La protection contre l'inflammation provoquée par l'aérosol est efficace pour une longue période et les souris traitées résistent à une seconde ré- exposition. Le transfert de cellules CD4+ issues de ganglions bronchiques et de poumons de souris traitées à l'OVA protège les souris asthmatiques receveuses contre les effets inflammatoires d'un aérosol, indiquant que des cellules T CD4+ régulatrices pourraient être impliquées dans cette protection. RESUME DESTINE A UN LARGE PUBLIC L'asthme est une affection des voies respiratoires qui se caractérise par une contraction de la musculature des voies aériennes, une production de mucus et d'anticorps de l'allergie (IgE). On parle d'asthme allergique lorsque les facteurs déclenchant l'asthme sont des allergènes inhalés tels que acariens, pollens ou poils d'animaux. Le système immunitaire des patients asthmatiques a un défaut de programmation qui le rend réactif à des substances qui sont normalement inoffensives. Le traitement actuel de l'asthme repose sur le soulagement des symptômes grâce à des produits à base de stéroïdes. Les techniques permettant de reprogrammer le système immunitaire (immunothérapie) ne sont pas efficaces pour tous les antigènes et prennent beaucoup de temps. En conséquence, il est nécessaire de mieux comprendre les mécanismes sous-tendant une telle reprogrammation afin d'en améliorer le rendement et l'efficacité. Dans ce but, des modèles d'immunothérapie ont été mis au point chez la souris. Ils permettent une plus grande liberté d'investigation. Dans cette étude, un modèle d'asthme allergique dans la souris a été établi par une sensibilisation à un antigène particulier : l'ovalbumine (OVA). Ce modèle présente les caractéristiques principales de l'asthme humain : recrutement de cellules inflammatoires dans les poumons, augmentation de la production d'anticorps et de la résistance des bronches aux flux respiratoires. Cette souris asthmatique a ensuite été traitée par application nasale d'OVA. Comparées aux souris non traitées, les souris traitées à l'OVA ont moins de cellules inflammatoires dans leurs poumons et produisent moins d'anticorps IgE. D'autres marqueurs inflammatoires sont aussi fortement diminués. Des cellules de poumons ou de ganglions bronchiques prélevées sur des souris traitées injectées dans des souris asthmatiques améliorent les symptômes de l'asthme. Ces cellules pourraient donc avoir un rôle régulateur dans l'asthme. Les caractériser et les étudier afin d'être capable de les générer est crucial pour les futures thérapies de l'asthme.

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The goal of this study was to validate a French version of the Interpersonal Reactivity Index (IRI), a self-report questionnaire comprised of four subscales assessing affective (empathic concern and personal distress) and cognitive (fantasy and perspective taking) components of empathy. To accomplish this, 322 adults (18 to 89 years) completed the French version of the IRI (F-IRI). A confirmatory factor analysis confirmed the four-factor structure of the original IRI. The F-IRI showed good scale score reliability, test-retest reliability, and convergent validity, tested with the French version of the Empathy Quotient. These findings confirmed the reliability and validity of the F-IRI and suggest that the F-IRI is a useful instrument to measure self-reported empathy. In addition, we observed sex and age differences consistent with findings in the literature. Women reported higher scores in empathic concern and fantasy than men. Older adults reported less personal distress and less fantasy. (PsycINFO Database Record (c) 2013 APA, all rights reserved)

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AbstractOBJECTIVETo analyze the care implemented by the nursing team to promote the safety of adult patients and prevention of skin and mucosal lesions associated with the presence of lower airways invasive devices.METHODStudy with qualitative and quantitative approach, descriptive and exploratory type, whose investigative scenarios were adult inpatient units of a hospital in the West Frontier of Rio Grande do Sul. The study subjects consisted of nurses, nursing technicians and nursing assistants.RESULTSA total of 118 professionals were interviewed. We highlight the observed specific care with endotracheal tube and tracheostomy, management and assessment of the cuff and the criteria used to secretion aspiration.CONCLUSIONThere is a superficial nursing work in the patient direct care and a differentiation in relation to the perception of nurse technicians, especially those working in the intensive care unit, who presented major property and view of the patient's clinical status.

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Our purpose is to determine the inflammatory changes in the airways of allergic paediatric asthma patients treated with omalizumab, measured by the percentage of eosinophils in induced sputum and exhaled nitric oxide (FENO). We observed a progressive and statistically significant decrease of eosinophil count in the induced sputum meanwhile FENO, although very sensible, was a less reproducible and thus a less reliable method to evaluate chronic airway inflammation in this population. Induced sputum seems to be a better method to monitor chronic inflammation and thus the response to chronic omalizumab treatment while FENO measurement would be more useful to monitor acute events preceding exacerbations.

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IL-28 (IFN-λ) cytokines exhibit potent antiviral and antitumor function but their full spectrum of activities remains largely unknown. Recently, IL-28 cytokine family members were found to be profoundly down-regulated in allergic asthma. We now reveal a novel role of IL-28 cytokines in inducing type 1 immunity and protection from allergic airway disease. Treatment of wild-type mice with recombinant or adenovirally expressed IL-28A ameliorated allergic airway disease, suppressed Th2 and Th17 responses and induced IFN-γ. Moreover, abrogation of endogenous IL-28 cytokine function in IL-28Rα(-/-) mice exacerbated allergic airway inflammation by augmenting Th2 and Th17 responses, and IgE levels. Central to IL-28A immunoregulatory activity was its capacity to modulate lung CD11c(+) dendritic cell (DC) function to down-regulate OX40L, up-regulate IL-12p70 and promote Th1 differentiation. Consistently, IL-28A-mediated protection was absent in IFN-γ(-/-) mice or after IL-12 neutralization and could be adoptively transferred by IL-28A-treated CD11c(+) cells. These data demonstrate a critical role of IL-28 cytokines in controlling T cell responses in vivo through the modulation of lung CD11c(+) DC function in experimental allergic asthma. →See accompanying Closeup by Michael R Edwards and Sebastian L Johnston http://dx.doi.org/10.1002/emmm.201100143.

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BACKGROUND: Food allergy has reached an epidemic level in westernized countries and although central mechanisms have been described, the variability associated with genetic diversity underscores the still unresolved complexity of these disorders. OBJECTIVE: To develop models of food allergy and oral tolerance, both strictly induced by the intestinal route, and to compare antigen-specific responses. METHODS: BALB/c mice were mucosally sensitized to ovalbumin (OVA) in the presence of the mucosal adjuvant cholera toxin, or tolerized by intra-gastric administrations of OVA alone. Antibody titres and cytokines were determined by ELISA, and allergic status was determined through several physiologic parameters including decline in temperature, diarrhoea, mast cell degranulation and intestinal permeability. RESULTS: OVA-specific antibodies (IgE, IgGs and IgA in serum and feces) were produced in sensitized mice exclusively. Upon intra-gastric challenge with OVA, sensitized mice developed anaphylactic reactions associated with a decline of temperature, diarrhoea, degranulation of mast cells, which were only moderately recruited in the small intestine, and increased intestinal permeability. Cytokines produced by immune cells from sensitized mice included T-helper type 2 cytokines (IL-5, IL-13), but also IL-10, IFN-gamma and IL-17. In contrast, all markers of allergy were totally absent in tolerized animals, and yet the latter were protected from subsequent sensitization, demonstrating that oral tolerance took place efficiently. CONCLUSION: This work allows for the first time an appropriate comparison between sensitized and tolerized BALB/c mice towards OVA. It highlights important differences from other models of allergy, and thus questions some of the generally accepted notions of allergic reactions, such as the protective role of IFN-gamma, the importance of antigen-specific secretory IgA and the role of mucosal mast cells in intestinal anaphylaxis. In addition, it suggests that IL-17 might be an effector cytokine in food allergy. Finally, it demonstrates that intestinal permeability towards the allergen is increased during challenge.

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NK cells can kill transformed, infected and stressed cells while most normal cells are spared. NK cells are activated by various endogenous self-ligands, some of which are actually expressed by normal cells. Thus, NK cells are inherently self-reactive and consequently, potentially auto-aggressive. How these cells are prevented from attacking normal cells while ensuring reactivity to diseased cells is a major unresolved question for NK-cell biologists.

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The mycolyl transferase antigen 85 complex is a major secreted protein family from mycobacterial culture filtrate, demonstrating powerful T cell stimulatory properties in most HIV-negative, tuberculin-positive volunteers with latent M.tuberculosis infection and only weak responses in HIV-negative tuberculosis patients. Here, we have analyzed T cell reactivity against PPD and Ag85 in HIV-infected individuals, without or with clinical symptoms of tuberculosis, and in AIDS patients with disease caused by nontuberculous mycobacteria. Whereas responses to PPD were not significantly different in HIV-negative and HIV-positive tuberculin-positive volunteers, responses to Ag85 were significantly decreased in the HIV-positive (CDC-A and CDC-B) group. Tuberculosis patients demonstrated low T cell reactivity against Ag85, irrespective of HIV infection, and finally AIDS patients suffering from NTM infections were completely nonreactive to Ag85. A one-year follow-up of twelve HIV-positive tuberculin-positive individuals indicated a decreased reactivity against Ag85 in patients developing clinical tuberculosis, highlighting the protective potential of this antigen.