Ion and fluid transport properties of small airways in cystic fibrosis

Rationale: Small airways constitute amajor site of pathology in cystic fibrosis (CF) and provide most of the surface area of the conducting airways of the lung. Little is known, however, about the impact of CF on ion and fluid transport in small (bronchiolar) airways. Objectives: To describe the ion and fluid transport properties of CF bronchiolar epithelium. Methods: Primary cultures of human bronchial and bronchiolar (non-CF and CF) epithelial cells were obtained. The bioelectric properties were studied in Ussing chambers and the airway surface liquid (ASL) height was measured with confocal microscopy. Main Results: Primary cultures of ΔF508 CF bronchiolar epithelial cells displayed higher transepithelial resistance than non-CF cultures, whereas baseline short circuit current and amiloride-inhibitable short circuit current were similar in both preparations. The ASL height was significantly smaller in CF compared with non-CF preparations. In the presence of amiloride, addition of forskolin increased short circuit current in non-CF but not in CF bronchiolar cultures, and the ATP-induced increase in short circuit current was lower in CF than in non-CF cultures. Non-CF bronchiolar preparations displayed larger short circuit current and fluid secretion in responses to forskolin than non-CF bronchial preparations, suggesting that CFTR-dependent Cl- transport may play a more important role in the regulation of fluid transport in small airways than in large airways. Conclusion: In CF small airways, defective Cl- secretion combined with unregulated (persistent) Na+ absorption results in ASLdepletion

Limited Increase of Particle Entrainment in the Off-Gas System of a Cold Crucible Induction Melter Compared with a Joule-Heated Metal Melter for HLLW Vitrification -11465

ABSTRACT Fission product solutions arising from reprocessing spent fuel from the nuclear reactors used for electrical production in France are immobilized in six vitrification lines at the AREVA La Hague plant. In 2010, the conventional Joule-heated metal melter was replaced in one of these six lines with a cold crucible melter. The cold crucible melter began vitrifying radioactive effluents produced by rinsing operations in legacy facilities in April 2010. The composition of these effluents requires a containment glass synthesis temperature that exceeds the operating temperatures limits of conventional ("hot") melters. The cold crucible melter technology has three main advantages: melt temperatures well above the current limit, increased glass production capacity, extended lifetime because of the lower wall temperatures. For these reasons the cold crucible melter can subsequently be used to vitrify a wide range of High-Level Liquid Waste (HLLW). This paper describes the assessment performed to characterize the entrainment of particles or chemicals and/or radioactive species to the off-gas treatment system from a Joule-heated metal melter (JHMM) and from a cold crucible induction melter (CCIM). Vitrification is performed in a two-step process. A calciner is used in each case to dry and calcine the high-level liquid waste, supplying only the dry residue to the melter together with glass frit. The off-gas treatment is identical for both melters. The paper first describes how the CEA uses its reconfigurable vitrification prototype, a full-scale mockup of a La Hague vitrification line, in support of AREVA to anticipate cold crucible melter operation under radioactive conditions. It describes the process equipment constituting the vitrification line from the melter (using a JHMM or a CCIM) to the off-gas treatment system. All the differences that contribute to the modification of radioactive particle entrainment from the calciner/melter to the off-gas treatment system are then described. The results obtained are then discussed concerning the volatility of species produced by vitrification during weekly tests implementing either the conventional melting pot or the cold crucible melter. The distribution of volatile species in the off-gas treatment devices is discussed. The paper concludes with a discussion of how using the CCIM vitrification process on one of the La Hague vitrification units can achieve an increased vitrification throughput at a higher temperature without any impact on the resulting waste release

Causas de Morte em Doentes com Hemofilia: Estudo Retrospectivo de 1979 a 2007, no Serviço de Imunohemoterapia do HSJ

Neurokinin A (NKA) induces bronchoconstriction mediated by tachykinin NK2 receptors in animals and humans, and may be increased in asthma. Because beta(2)-adrenoceptor agonists are the most widely used bronchodilators in asthma, we investigated the effects of the beta(2)-adrenoceptor agonist fenoterol on NK2 receptor messenger RNA (mRNA) and receptor density as well as the functional responses of bovine tracheal smooth muscle to the NK2 receptor agonist [beta-Ala(8)]-NKA(4-10) in vitro, using Northern blot analysis, receptor binding, and organ bath studies. Incubation with fenoterol induced a time- and concentration-dependent upregulation of NK2 receptor mRNA (71% increase after 12 h at 10(-7) M fenoterol), which was abolished by propranolol (a nonselective beta-adrenoceptor agonist) and ICI118551 (a selective beta(2)-adrenoceptor antagonist), but not by CGP20712A (a selective beta(1)-adrenoceptor antagonist), indicating that fenoterol acts via beta(2)-adrenoceptors. These effects were mimicked by forskolin and prostaglandin E-2 (PGE,), both agents that increase cyclic adenosine monophosphate (cAMP), and by the cAMP analogue 8-bromo-cAMP. The upregulation was blocked by cycloheximide, indicating that it requires new protein synthesis, and was accompanied by an increase in both the stability of NK2 receptor mRNA and the rate of NK2 receptor gene transcription. Radioligand binding assay using the selective NK2 receptor antagonist [H-3]SR48968 showed a significant increase in the number of receptor binding sites after 12 h and 18 h, which was accompanied by an increased contractile responsiveness to the NK2 receptor agonist [beta-Ala(8)]-NKA(4-10). Dexamethasone completely prevented the fenoterol-induced increase in NK2 receptor mRNA and in the contractile response. We conclude that beta(2)-adrenoceptor agonists induce upregulation of functional NK2 receptors in airway smooth muscle by increasing cAMP, and that this can be prevented by a corticosteroid. The increased responsiveness could be relevant to asthma control and mortality

Effect of pre-contraction on β-adrenoceptor-mediated relaxation of rat urinary bladder

Purpose The human physiological bladder contraction is largely mediated by acetylcholine acting on muscarinic receptors, but in pathophysiological settings the relative role of non-cholinergic stimuli gains importance. beta-Adrenoceptor agonists are currently in clinical development as treatments for the overactive bladder syndrome. Therefore, we have explored the ability of the beta-adrenoceptor agonist isoprenaline to induce rat isolated bladder strip relaxation on pre-contraction with the muscarinic agonist carbachol as compared to bladder tone induced by several non-cholinergic stimuli. Methods Bladder tone was induced by passive tension, receptor independently by KCl, carbachol, bradykinin or serotonin. Concentration-response curves were generated for relaxation by isoprenaline, and a single concentration of the receptor-independent relaxant forskolin was also tested. Results The various contractile stimuli induced different degrees of bladder tone, but the ability of isoprenaline or forskolin to relax rat bladder was not correlated with the degree of tone. Isoprenaline was significantly less potent and effective in causing relaxation against carbachol-induced tone than against any other stimulus, whereas no such relationship was observed for forskolin. Conclusions We conclude that beta-adrenoceptor agonists can induce rat bladder relaxation against a wide range of contractile stimuli and are more potent and/or effective against non-cholinergic stimuli than against muscarinic agonism. This profile appears desirable for agents intended for the treatment of overactive bladde

Cardiac safety of indacaterol in healthy subjects: a randomized, multidose, placebo- and positive-controlled, parallel-group thorough QT study

<p>Abstract</p> <p>Background</p> <p>Indacaterol is a novel once-daily ultra long-acting β₂-agonist for the treatment of chronic obstructive pulmonary disease. It is known that β₂-agonists, like other adrenergic compounds, can prolong the QT-interval. This thorough QT/QTc study (as per ICH E14 guideline) evaluated the effect of indacaterol on the QT interval in healthy subjects.</p> <p>Methods</p> <p>In this randomized, double-blind, parallel-group, placebo- and positive-controlled (open-label moxifloxacin) study, non-smoking healthy subjects (18-55 years, body mass index: 18.5-32.0 kg/m²) were randomized (4:4:2:4:1) to 14-day treatment with once-daily indacaterol (150 μg, 300 μg, or 600 μg), placebo, or placebo/moxifloxacin (double-blind 14-day treatment with placebo and a single open-label dose of 400 mg moxifloxacin on Day 14). The primary endpoint was the change from baseline on Day 14 in QTcF (QT interval corrected for heart rate using Fridericia's formula).</p> <p>Results</p> <p>In total, 404 subjects were randomized to receive indacaterol (150 [n = 108], 300 [n = 108], 600 μg [n = 54]), placebo (n = 107), or placebo/moxifloxacin (n = 27); 388 subjects completed the study. Maximal time-matched mean (90% confidence intervals) treatment differences from placebo in QTcF change from baseline on Day 14 were 2.66 (0.55, 4.77), 2.98 (1.02, 4.93) and 3.34 (0.86, 5.82) ms for indacaterol 150 μg, 300 μg and 600 μg, respectively. Study sensitivity was confirmed with moxifloxacin demonstrating a significant maximal time-matched QTcF prolongation of 13.90 (10.58, 17.22) ms compared to placebo. All indacaterol doses were well tolerated.</p> <p>Conclusion</p> <p>Indacaterol, at doses up to 600 μg once daily (2-4 times the therapeutic dose) does not have any clinically relevant effect on the QT interval.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01263808">NCT01263808</a></p

Expression and function of human hemokinin-1 in human and guinea pig airways

<p>Abstract</p> <p>Background</p> <p>Human hemokinin-1 (hHK-1) and endokinins are peptides of the tachykinin family encoded by the <it>TAC4 </it>gene. <it>TAC4 </it>and hHK-1 expression as well as effects of hHK-1 in the lung and airways remain however unknown and were explored in this study.</p> <p>Methods</p> <p>RT-PCR analysis was performed on human bronchi to assess expression of tachykinin and tachykinin receptors genes. Enzyme immunoassay was used to quantify hHK-1, and effects of hHK-1 and endokinins on contraction of human and guinea pig airways were then evaluated, as well as the role of hHK-1 on cytokines production by human lung parenchyma or bronchi explants and by lung macrophages.</p> <p>Results</p> <p>In human bronchi, expression of the genes that encode for hHK-1, tachykinin NK₁-and NK₂-receptors was demonstrated. hHK-1 protein was found in supernatants from explants of human bronchi, lung parenchyma and lung macrophages. Exogenous hHK-1 caused a contractile response in human bronchi mainly through the activation of NK₂-receptors, which blockade unmasked a NK₁-receptor involvement, subject to a rapid desensitization. In the guinea pig trachea, hHK-1 caused a concentration-dependant contraction mainly mediated through the activation of NK₁-receptors. Endokinin A/B exerted similar effects to hHK-1 on both human bronchi and guinea pig trachea, whereas endokinins C and D were inactive. hHK-1 had no impact on the production of cytokines by explants of human bronchi or lung parenchyma, or by human lung macrophages.</p> <p>Conclusions</p> <p>We demonstrate endogenous expression of <it>TAC4 </it>in human bronchi, the encoded peptide hHK-1 being expressed and involved in contraction of human and guinea pig airways.</p

Smoking particles enhance endothelin A and endothelin B receptor-mediated contractions by enhancing translation in rat bronchi

BACKGROUND: Smoking is known to cause chronic inflammatory changes in the bronchi and to contribute to airway hyper-reactivity, such as in bronchial asthma. To study the effect of smoking on the endothelin system in rat airways, bronchial segments were exposed to DMSO-soluble smoking particles (DSP) from cigarette smoke, to nicotine and to DMSO, respectively. METHODS: Isolated rat bronchial segments were cultured for 24 hours in the presence or absence of DSP, nicotine or DMSO alone. Contractile responses to sarafotoxin 6c (a selective agonist for ET(B )receptors) and endothelin-1 (an ET(A )and ET(B )receptor agonist) were studied by use of a sensitive myograph. Before ET-1 was introduced, the ET(B )receptors were desensitized by use of S6c. The remaining contractility observed was considered to be the result of selective activation of the ET(A )receptors. ET(A )and ET(B )receptor mRNA expression was analyzed using real-time quantitative PCR. The location and concentration of ET(A )and ET(B )receptors were studied by means of immunohistochemistry together with confocal microscopy after overnight incubation with selective antibodies. RESULTS: After being cultured together with DSP for 24 hours the bronchial segments showed an increased contractility mediated by ET(A )and ET(B )receptors, whereas culturing them together with nicotine did not affect their contractility. The up-regulation of their contractility was blunted by cycloheximide treatment, a translational inhibitor. No significant change in the expression of ET(A )and ET(B )receptor mRNA through exposure to DMSO or to nicotine exposure alone occurred, although immunohistochemistry revealed a clear increase in ET(A )and ET(B )receptors in the smooth muscle after incubation in the presence of DSP. Taken as a whole, this is seen as the presence of a translation mechanism. CONCLUSION: The increased contractility of rat bronchi when exposed to DSP appears to be due to a translation mechanism

Muscarinic receptor subtypes and signalling involved in the attenuation of isoprenaline-induced rat urinary bladder relaxation

β-Adrenoceptors are important mediators of smooth muscle relaxation in the urinary bladder, but the concomitant presence of a muscarinic agonist, e.g., carbachol, can attenuate relaxation responses by reducing potency and/or efficacy of β-adrenoceptor agonists such as isoprenaline. Therefore, the present study was designed to explore the subtypes and signalling pathways of muscarinic receptors involved in the attenuation of isoprenaline-induced isolated rat detrusor preparations using novel subtype-selective receptor ligands. In radioligand binding studies, we characterized BZI to be a M3-sparing muscarinic agonist, providing selective M2 stimulation in rat bladder, and THRX-182087 as a highly M2-selective antagonist. The use of BZI and of THRX-182087 in the presence of carbachol enabled experimental conditions with a selective stimulation of only M2 or M3 receptors, respectively. Confirming previous findings, carbachol attenuated isoprenaline-induced detrusor relaxation. M2-selective stimulation partly mimicked this attenuation, indicating that both M2 and M3 receptors are involved. During M3-selective stimulation, the attenuation of isoprenaline responses was reduced by the phospholipase C inhibitor U 73,122 but not by the protein kinase C inhibitor chelerythrine. We conclude that both M2 and M3 receptors contribute to attenuation of β-adrenoceptor-mediated relaxation of rat urinary bladder; the signal transduction pathway involved in the M3 component of this attenuation differs from that mediating direct contractile effects of M3 receptors

Neurotrophins and neurotrophin receptors in pulmonary sarcoidosis - granulomas as a source of expression

<p>Abstract</p> <p>Background</p> <p>Pulmonary sarcoidosis is an inflammatory disease, characterized by an accumulation of CD4⁺lymphocytes and the formation of non-caseating epithelioid cell granulomas in the lungs. The disease either resolves spontaneously or develops into a chronic disease with fibrosis. The neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) have been suggested to be important mediators of inflammation and mediate tissue remodelling. In support of this, we have recently reported enhanced NGF levels in the airways of patients with pulmonary sarcoidosis. However, less is known about levels of BDNF and NT-3, and moreover, knowledge in the cellular sources of neurotrophins and the distribution of the corresponding neurotrophin receptors in airway tissue in sarcoidosis is lacking.</p> <p>Methods</p> <p>The concentrations of NGF, BDNF and NT-3 in bronchoalveolar lavage fluid (BALF) of 41 patients with newly diagnosed pulmonary sarcoidosis and 27 healthy controls were determined with ELISA. The localization of neurotrophins and neurotrophin receptors were examined by immunohistochemistry on transbronchial lung biopsies from sarcoidosis patients.</p> <p>Results</p> <p>The sarcoidosis patients showed significantly enhanced NT-3 and NGF levels in BALF, whereas BDNF was undetectable in both patients and controls. NT-3 levels in BALF were found higher in patients with non-Löfgren sarcoidosis as compared to patients with Löfgren's syndrome, and in more advanced disease stage. Epithelioid cells and multinucleated giant cells within the sarcoid granulomas showed marked immunoreactivity for NGF, BDNF and NT-3. Also, immunoreactivity for the neurotrophin receptor TrkA, TrkB and TrkC, was found within the granulomas. In addition, alveolar macrophages showed positive immunoreactivity for NGF, BDNF and NT-3 as well as for TrkA, TrkB and TrkC.</p> <p>Conclusions</p> <p>This study provides evidence of enhanced neurotrophin levels locally within the airways of patients with sarcoidosis. Findings suggest that sarcoid granuloma cells and alveolar macrophages are possible cellular sources of, as well as targets for, neurotrophins in the airways of these patients.</p