A faringe é um órgão muscular que se sustenta nos ossos da face e crânio. Dividindo-se em naso, oro e hipofaringe, pode ser considerada um tubo colabável que atende aos sistemas respiratório e digestivo, participando da respiração, deglutição e fonação. Sua conformação anatômica permite que fatores como obesidade, hipotonia muscular e deficiência mandibular favoreçam sua obstrução, podendo gerar a Síndrome da Apnéia Obstrutiva do Sono (SAOS). Para os pacientes portadores de deficiência mandibular, o tratamento deve desobstruir a faringe por meio de avanço mandibular, aumentando as dimensões faríngeas. A determinação do local de obstrução é fundamental para o adequado tratamento, sendo a análise cefalométrica convencional ou computadorizada, ferramenta útil nesse processo. Da mesma forma que o avanço mandibular aumenta o espaço aéreo faríngeo, espera-se que o recuo de mandíbula reduza-o. Com o objetivo de avaliar as alterações cefalométricas do espaço aéreo faríngeo frente aos procedimentos de cirurgia ortognática para correção de prognatismo mandibular, realizou-se a análise cefalométrica pré e pós-operatória de 19 pacientes submetidos a recuo de mandíbula pela técnica da osteotomia sagital de mandíbula bilateral associada a avanço de maxila por meio de osteotomia Le Fort I, utilizando-se o Programa Dolphin Imaging 10.0. Os resultados obtidos com base nas características do grupo de pacientes estudado não evidenciaram alterações estatisticamente significativas nos espaços aéreos faríngeos superior ou nasofaríngeo, médio ou orofaríngeo e inferior ou hipofaríngeo, o que permitiu concluir que o Programa Dolphin Imaging 10.0 pode ser utilizado como ferramenta para análise cefalométrica do espaço aéreo faríngeo e que a cirurgia ortognática maxilo/mandibular, para correção de prognatismo mandibular, parece não alterar os espaços aéreos faríngeos. / Pharynx is a muscular organ with is sustained by craniofacial bones. It is divided into nasal, oral and hipopharynx, and can be considered as a tube that can be closed serving both respiratory and digestive systems, participating of breathing, swallowing and speech. Its anatomical morphology permits that factors such as obesity, muscular hipotony, and mandibular deficiency, among others, facilitate its obstruction, leading to the sleep apnea syndrome (OAS). The treatment consists of surgical mandibular advancement for the desobstruction of the pharynx, once this procedure increases pharyngeal dimensions. In this context, the determination of the site of the obstruction is essential for an adequate treatment, and conventional or digital cephalometries are useful tools for this diagnosis. If mandible advancement increases pharyngeal air space it is expected that mandible setback decreases such space. In order to evaluate cephalometric alterations of pharyngeal air space after orthognatic surgeries for the correction of mandibular prognatism, cephalometric analysis of 18 patients before and after surgical correction were performed using Dolphin Imaging 10.0 Program. The surgical technique consisted of bilateral mandibular sagital osteotomy associated to maxilla advancement and mentoplasty. Results did not reveal statistical differences for 142 the superior (naso), medium (oral), and inferior (hypopharynx) pharyngeal air spaces, leading to the conclusion that Dolphin Imaging 10.0 Program can be used for the analysis of the pharyngeal air space and that the surgical procedure seems not to interfere in the airway space.

La broncho-pneumopathie chronique obstructive (BPCO) est une maladie respiratoire inflammatoire chronique caractérisée par une limitation progressive et irréversible des débits aériens causée par l’inhalation à long terme de particules nocives telles que le tabac. La BPCO présente un remodelage majeur et hétérogène des voies aériennes comportant une grande variabilité inter-individuelle. La réponse inflammatoire et immunitaire au cours de la BPCO est caractérisée par une infiltration du tissu respiratoire par les polynucléaires neutrophiles (PN), les macrophages et par les cellules T. La dégradation des fibres élastiques du poumon en peptides solubles d’élastine (PE) par le biais de la sécrétion de protéases par les cellules de l’immunité innée est une caractéristique constante de la BPCO. Ces PE participent à la physiopathologie de la BPCO comme cela a été démontré dans différents modèles murins de la maladie emphysémateuse. L’orientation de la réponse des cellules T helper (Th) et des cellules T cytotoxiques (Tc) au cours de la BPCO n’est pas élucidée et reste controversée. L’objectif principal de ce travail de thèse a été de définir l’orientation de la réponse Th et Tc ainsi que le rôle des PE dans le remodelage associé à la BPCO. Pour cela, nous avons étudié la signature cytokinique Th-1/Tc-1 (IFN-), Th-2/Tc-2 (IL-4), Th-17/Tc-17 (IL-17) spécifique du remodelage bronchique associé à la BPCO au niveau cellulaire, mais également transcriptionnel et fonctionnel. L’association entre les résultats expérimentaux obtenus et le phénotype des patients inclus a été analysé de manière à déterminer le rôle de ces mécanismes dans l’expression clinique de cette pathologie respiratoire chronique. Les résultats obtenus ont mis en évidence une diminution de l’expression de l’IL-4 (Th2) chez les patients BPCO par rapport aux sujets contrôles ainsi qu’une potentialisation de l’expression de cette cytokine en présence des PE. / Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory respiratory pathology characterized by a progressive and irreversible limitation of airflow caused by the long-term inhalation of harmful particles such as tobacco. COPD presents a major and heterogeneous remodeling of the airways with important inter-individual variability. The inflammatory and immune response during COPD is characterized by infiltration of pulmonary tissue by neutrophils (PN), macrophages, and T cells. The degradation of lung elastic fibers into soluble elastin peptides (EP) is caused by the secretion of proteases by innate immunity cells and it is a consistent feature of COPD. These EP participate in the pathophysiology of COPD as demonstrated in different murine models of the emphysematous disease. The T helper (Th) and the T cytotoxic (Tc) orientation during COPD is unclear andremains controversial. The main objective of this work was to define the Th and Tc responses as well as the role ofEP in airways remodeling associated to COPD. For this purpose, we studied the cytokine signature Th-1/Tc-1 (IFN- ), Th-2/Tc-2 (IL-4), Th-17/Tc-17 (IL-17) specific of the airway remodeling associated to COPD both at the cellular, transcriptional and functional level. Association between the experimental results obtained and the phenotype of the patients included in the study was analyzed in order to determine the role of these mechanisms in the clinical expression of this chronic respiratory pathology. The results obtained showed a decrease in the expression of IL-4 (Th2) in COPD patients compared to control subjects as well as a potentiation of this cytokine expression in the presence of EP.

by Martin Li. / Year shown on spine: 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 150-157). / DECLARATION --- p.II / ABSTRACT --- p.III / ACKNOWLEDGEMENTS --- p.VII / CONTENTS --- p.VIII / LIST OF ABBREVIATIONS --- p.XIV / LIST OF TABLES --- p.XVI / LIST OF CHART --- p.XXIII / LIST OF FIGURES --- p.XXIV / Chapter CHAPTER 1 --- OBSTRUCTIVE AIRWAY DISEASE: PUBLIC HEALTH AND CLINICAL ASPECTS --- p.1 / Chapter 1.1. --- Background --- p.1 / Chapter 1.2. --- Magnitude of the problem --- p.2 / Chapter 1.2.1. --- Asthma --- p.2 / Chapter 1.2.2. --- Chronic obstructive pulmonary disease --- p.3 / Chapter 1.2.3. --- Prevalence of osteoporosis in Hong Kong --- p.4 / Chapter 1.2.4. --- History of asthma care --- p.5 / Chapter 1.2.5. --- Treatment of OAD --- p.5 / Chapter 1.3. --- Side effects of Glucocorticoid in OAD patients --- p.6 / Chapter 1.4. --- Side effccts of inhaled corticosteroids in OAD patients --- p.7 / Chapter 1.5. --- Trend of asthma therapy in Hong Kong --- p.8 / Chapter CHAPTER 2: --- OSTEOPOROSIS: PUBLIC HEALTH AND CLINICAL ASPECTS --- p.11 / Chapter 2.1. --- Bone Biology --- p.11 / Chapter 2.2. --- Skeletal Organisation --- p.11 / Chapter 2.3. --- Bone remodelling --- p.12 / Chapter 2.4. --- Effect of corticosteroids on bone remodelling --- p.13 / Chapter 2.5. --- Corticosteroids induccs osteoporosis --- p.13 / Chapter 2.6. --- Factors affecting BMD --- p.14 / Chapter 2.6.1. --- Peak bone mass --- p.14 / Chapter 2.6.2. --- Ethnic factors --- p.14 / Chapter 2.6.3. --- Aging --- p.15 / Chapter 2.6.4. --- Calcium intake --- p.15 / Chapter 2.6.5. --- Oestrogen --- p.16 / Chapter 2.6.6. --- Alcohol consumption --- p.17 / Chapter 2.6.7. --- Cigarette smoking --- p.17 / Chapter 2.7. --- Physical activity and BMD --- p.17 / Chapter 2.8. --- Body composition in Chinese subjects --- p.18 / Chapter CHAPTER 3 --- "PHASE I: BODY COMPOSITION AND BONE MINERAL DENSITY IN OBSTRUCTIVE AIRWAY DISEASE PATIENT AND NORMAL CONTROL SUBJECTS: OBJECTIVES, SUBJECTS AND METHODS" --- p.20 / Chapter 3.1. --- Objectives --- p.20 / Chapter 3.2. --- Subjects and methods --- p.21 / Chapter 3.2.1 --- OAD patients --- p.21 / Chapter 3.2.1.1 --- Disease definition and selection criteria --- p.21 / Chapter 3.2.1.2. --- Normal Control subjects --- p.21 / Chapter 3.3. --- Power of estimation --- p.22 / Chapter 3.4. --- Survey methods --- p.22 / Chapter 3.5. --- Questionnaire --- p.23 / Chapter 3.6. --- Body composition and bone mineral density measurement --- p.23 / Chapter 3.6.1. --- Body composition analysis --- p.24 / Chapter 3.6.2. --- Lumbar spine and proximal hip bone mineral density analysis --- p.24 / Chapter 3.6.3. --- Routine quality control of measurements --- p.24 / Chapter 3.6.4. --- Precision on patient repositioning --- p.25 / Chapter 3.7. --- Statistical methods --- p.25 / Chapter 3.8. --- Bone mineral density of normal control subjects --- p.25 / Chapter CHAPTER 4 --- PHASE II: FLUORIDE IN THE TREATMENT OF OSTEOPOROSIS --- p.27 / Chapter 4.1. --- Introduction --- p.27 / Chapter 4.2. --- Mechanisms of action --- p.28 / Chapter 4.2.1. --- Antiresorptive effect of fluoride --- p.28 / Chapter 4.2.2. --- Force-oriented osteogenic effect of fluoride --- p.28 / Chapter 4.2.3. --- Biochemical osteogenic effect --- p.29 / Chapter 4.3. --- Effect of fluoride salts on BMD: results of clinical trials --- p.29 / Chapter 4.4. --- Effcct of fluoride on bone histomorphology --- p.30 / Chapter 4.5. --- Compliance with sodium fluoride therapy --- p.31 / Chapter 4.6. --- Contradiction of fluoride treatment --- p.31 / Chapter 4.7. --- Sodium monofluorophosphate preparation --- p.32 / Chapter CHAPTER 5 --- PHASE II: THE EFFECTS OF FLUORIDE ON BONE MINERAL DENSITY OF OAD PATIENTS ON STEROID TREATMENT --- p.37 / Chapter 5.1. --- Objectives --- p.37 / Chapter 5.2. --- Subjects and methods --- p.37 / Chapter 5.2.1. --- Power of the study --- p.37 / Chapter 5.2.2. --- Subjects --- p.37 / Chapter 5.2.3. --- Method of randomisation --- p.38 / Chapter 5.2.4. --- Treatment modalities --- p.39 / Chapter 5.2.4.1. --- Treatment group --- p.39 / Chapter 5.2.4.2. --- Control group --- p.39 / Chapter 5.2.5. --- Bone mineral density measurements --- p.39 / Chapter 5.2.6. --- Routine quality control of measurement and precision on patient repositioning --- p.40 / Chapter 5.2.7. --- Methods of monitoring drug compliance --- p.40 / Chapter 5.2.8 --- Statistical methods --- p.40 / Chapter CHAPTER 6 --- RESULTS FOR PHASE I --- p.42 / Chapter 6.1. --- Statistical power of this phase of the study --- p.42 / Chapter 6.2. --- Clinical features of OAD subjects on inhaled steroid --- p.42 / Chapter 6.3. --- Anthropometric measurements and bone mineral density --- p.45 / Chapter 6.4. --- Analysis of covariance for BMDs differences --- p.48 / Chapter 6.5. --- Multiple regression --- p.50 / Chapter 6.6 --- Correlation --- p.51 / Chapter CHAPTER 7 --- RESULTS FOR PHASE II: FLUORIDE AND CALCIUM TRIAL --- p.81 / Chapter 7.1. --- Factors affects the power of studies --- p.81 / Chapter 7.2. --- Clinical findings --- p.82 / Chapter 7.3. --- Body measurements and bone mineral densitometry --- p.85 / Chapter CHAPTER 8: --- DISCUSSION FOR PHASE I --- p.117 / Chapter CHAPTER 9: --- DISCUSSION FOR PHASE II: TRIDIN AND CALCIUM TRIAL --- p.124 / APPENDIX 1: QUESTIONNAIRE FOR OAD BONE MINERAL DENSITY STUDY --- p.132 / APPENDIX 2: BONE SCANS FROM HOLOGIC QDR2000 --- p.137 / APPENDIX 3. TABLES AND REFERENCE CURVES FOR NORMAL HONG KONG CHINESE FEMALE OR MALE BMD --- p.142 / REFERENCE --- p.150

Les objectifs de ce travail de thèse étaient d'évaluer et d'optimiser la prise en charge périopératoire des voies aériennes et de la ventilation mécanique du patient obèse nécessaire à une anesthésie générale.Dans un premier temps, nous avons spécifiquement analysé la prise en charge des voies aériennes chez le patient obèse. Deux larges bases de données, respectivement établies au bloc opératoire et en réanimation, ont été utilisées. La base de données de réanimation avait ainsi permis de développer et valider un score permettant de prédire l'intubation difficile en réanimation, le score de MACOCHA. L’analyse spécifique des patients obèses dans ces 2 bases de données a permis d’établir les facteurs de risque d’intubation difficile ainsi que les complications associées à l’intubation. Chez le patient obèse, les incidences de l'intubation difficile et des complications respiratoires sévères (hypoxémie), étaient respectivement 2 fois et 20 fois plus fréquentes en réanimation qu'au bloc opératoire. L'obésité n'était pas retrouvée comme facteur de risque de complication cardiovasculaire (collapsus) associée à l’intubation en réanimation.Dans un second temps, nous avons évalué la prise en charge des patients obèses en réanimation, notamment pour complication respiratoire. Après sécurisation des voies aériennes pour l’anesthésie générale, le patient obèse, surtout s’il est intubé en situation d’urgence, est à risque de développer un syndrome de détresse respiratoire aigüe (SDRA). Nous avons spécifiquement étudié l’une des thérapeutiques les plus efficaces du SDRA, le décubitus ventral, chez le patient obèse, montrant que cette technique était sûre et efficace. La survie était meilleure dans la population obèse. Afin d'expliquer ce meilleur pronostic du patient obèse en SDRA, nous avons émis l'hypothèse d'une meilleure fonction diaphragmatique. A travers un travail expérimental, cette hypothèse a été confirmée chez le rat: la force diaphragmatique était significativement plus importante chez les rats obèses, avant et après ventilation mécanique. Cette amélioration de la force diaphragmatique pourrait expliquer en partie le "paradoxe de l'obésité", à savoir que l'obésité est associée dans la littérature à un meilleur pronostic chez le patient critique. Toujours pour expliquer ce meilleur pronostic, nous avons analysé plus de 700 patients obèses de réanimation appariés sur le type d'admission, et montré que le type d'admission pour motif médical (vs motif chirurgical) était un facteur indépendant de mortalité. L'indice de gravité simplifié II, score le plus employé pour prédire la mortalité chez les patients de réanimation, surestimait la mortalité en cas d'admission chirurgicale. Un nouveau modèle prédisant la mortalité du patient obèse a ainsi été développé. Nous avons enfin étudié le patient obèse polytraumatisé : l’incidence de la transfusion massive lors des 24 premières heures de prise en charge était augmentée. Un score visant à guider la prise en charge précoce de ces patients obèses en choc hémorragique a par la suite été validé.Après optimisation de la prise en charge des voies aériennes et de la ventilation, le sevrage de la ventilation mécanique en réanimation peut être particulièrement compliqué chez le patient obèse, d’autant plus dans ce contexte de « voies aériennes difficiles ». Dans un troisième temps, nous avons ainsi comparé plusieurs épreuves de sevrage chez le patient obèse, afin de déterminer l'épreuve la plus représentative du travail respiratoire post-extubation. Nous avons montré que chez le patient obèse, seule la ventilation spontanée sans aucune assistance ventilatoire mécanique permettait de prédire le succès de l’extubation.Ces résultats seront le support de la mise en place d’études contrôlées randomisées, visant à comparer des stratégies thérapeutiques chez le patient obèse pour diminuer les complications de l'intubation, de la ventilation et les échecs d'extubation en médecine périopératoire. / The objectives of this thesis were to evaluate and improve the perioperative airway and ventilation management of the obese patient.First, we specifically analyzed the airway management of obese patients. Two large databases, established respectively in the operating room and intensive care unit (ICU), were used. The ICU database was used to develop and validate a score for predicting difficult endo-tracheal intubation in ICU in the general population, the MACOCHA score. In the same database, obesity was not found to be a risk factor of severe cardiovascular collapse after intubation. The specific analysis of obese patients in these two databases identified risk factors of difficult intubation in the operating room and intensive care. In obese patients, difficult intubation and severe complications such as hypoxemia, were respectively twice and twenty times more common in intensive care than in the operating room.Secondly, obese patients, especially if they are intubated in an emergency situation, are at greater risk of developing acute respiratory distress syndrome (ARDS) after the airway is secured for general anesthesia. We specifically studied one of the most effective treatment of ARDS, prone positioning, in obese patients, showing that this technique is safe and effective. Survival was better in obese patients than in non-obese patients. To explain this better prognosis of obese patients with ARDS, we hypothesized that their diaphragmatic function might be better. This hypothesis was confirmed experimentally in rat specimens: diaphragmatic strength was significantly greater in obese rats then in non-obese rats, before and after mechanical ventilation. This increased diaphragmatic strength may partially explain the "obesity paradox", i.e. that obesity is associated with a better prognosis in the critical care setting. In order to further explain this better prognosis, we analyzed more than 700 obese patients after matching for admission type (medical or surgical). This analysis showed that ICU admission on medical grounds was an independent risk factor for mortality compared to a surgical cause of admission. The Simplified Acute Physiology Score II, the severity index most often used to predict mortality in critically ill patients, overestimated mortality in case of surgical admission in obese patients. A new model predicting mortality in obese patients was developed. Finally we specifically studied obese patients with multiple trauma. The proportion of massive transfusion during the first 24 hours of support was increased in these patients. A score to guide the early management of these obese patients in hemorrhagic shock has subsequently been validated.Once optimal airway and ventilation management is achieved, weaning from mechanical ventilation can be particularly difficult in obese patients, especially in the context of "difficult airway". We therefore proceeded in a third part to compare several weaning trials in obese patients, in order to determine the most representative test to predict post-extubation respiratory work. It was the T-piece or the total absence of mechanical support (0 pressure support and 0 positive airway pressure) that best predicted post-extubation respiratory work.These results will support the implementation of randomized controlled trials comparing specific therapeutic strategies in obese patients to reduce complications of intubation, ventilation and extubation failure in perioperative medicine.

Objetivos: Comparar os efeitos dos tratamentos com montelucaste e dexametasona no recrutamento eosinofílico e na avaliação de células positivas para eotaxina, RANTES, fibronectina, IGF-I e NF-B tanto no parênquima pulmonar distal, quanto nas vias aéreas de cobaias com inflamação alérgica crônica. Métodos: As cobaias receberam inalação com ovoalbumina (grupo OVA- 2 vezes semanais, durante 4 semanas, totalizando 7 inalações). Após a quarta inalação, as cobaias foram tratadas com montelucaste (grupo OVA-M: 10mg/Kg/VO/dia) ou dexametasona ( grupo OVA-D: 5mg/Kg/IP/dia). Após 72 horas da sétima inalação, as cobaias foram anestesiadas e os pulmões foram removidos e submetidos a avaliação histopatológica. Resultados: Os tratamentos com montelucaste e dexametasona reduziram o número de eosinófilos tanto no parênquima pulmonar distal quanto nas vias aéreas, quando comparados ao grupo OVA (p<0.05). No parênquima pulmonary distal, ambos os tratamentos foram efetivos na redução de células positivas para RANTES, NF-B e fibronectina, quando comparados ao grupo OVA (p<0.001). O tratamento com montelucaste mostrou melhor eficácia na redução de células positivas para eotaxina, quando comparado ao tratamento com dexametasona (p<0.001), por outro lado, o tratamento com dexametasona mostrou-se mais significativo na redução de células positivas para IGF-I, quando comparado ao tratamento com montelucaste (p<0.001). Nas vias aéreas, ambos os tratamentos foram efetivos na redução de células positivas para IGF-I, RANTES e fibronectina, quando comparados ao grupo OVA (p<0.05). O tratamento com dexametasona foi mais efetivo na redução de células positivas para eotaxina e NF-B, quando comparado ao tratamento com montelucaste (p<0.05). Conclusões: Neste modelo animal, ambos os tratamentos foram efetivos no controle da resposta inflamatória, tanto no parênquima pulmonar distal, quanto nas vias aéreas / Aims: Compare the effects of montelukast or dexamethasone treatments on eosinophilic recruitment, eotaxin, RANTES, fibronectin, IGF-I and NF-B positive cells of distal lung parenchyma and also in airway walls of guinea pigs (GP) with chronic allergic inflammation. Methods: GP were inhaled with ovalbumin (OVA group-2x/week/4weeks). After 4th inhalation, GP were treated with montelukast (M group: 10mg/Kg/PO/day) or dexamethasone (D group: 5mg/Kg/IP/day). After 72 hrs of 7th inhalation, GP were anesthetised, lungs were removed and submitted to histopathological evaluation. Results: Montelukast and dexamethasone treatments reduced the number of eosinophils both in airway wall as well as in distal lung parenchyma compared to OVA group (p<0.05). On distal parenchyma both montelukast and dexamethasone were effective in reducing RANTES, NF-B and fibronectin positive cells compared to OVA group (p<0.001). Montelukast was more effective in reducing the eotaxin positive cells on distal parenchyma compared to dexamethasone treatment (p<0.001), while there was a more expressive reduction of IGF-I positive cells in OVA-D group (p<0.001). On airway walls, both montelukast and dexamethasone were effective in reducing IGF-I, RANTES and fibronectin positive cells compared to OVA group (p<0.05). Dexamethasone was more effective reducing the number of eotaxin and NF-kB positive cells than Montelukast (p<0.05). Conclusions: In this animal model, both treatments were effective in modulating the eosinophilic response in distal lung parenchyma and in airway wall, contributing to a better control of the inflammatory response in distal lung parenchyma as well as in airway walls. Dexamethasone treatment induced a greater reduction of NF-B expression in airway walls which suggests one of the mechanisms that explains the higher efficacy of this therapeutic approach

Objetivos: Determinar o percentual de asmáticos com má percepção da dispnéia e sua correlação com a intensidade da broncoconstrição aguda, hiper-responsividade brônquica, uso de medicação de manutenção e controle da asma. Métodos: Ensaio clínico não controlado com pacientes asmáticos do ambulatório de asma do Hospital São Lucas da PUCRS. Foram realizados testes de broncoprovocação com metacolina com protocolo dosimetrado e avaliada a percepção da dispnéia após cada dose administrada, utilizando a escala de Borg. Foram coletados dados demográficos e questionado quanto ao controle da asma, medicação em uso e necessidade de broncodilatador de curta ação. Para análise estatística foram utilizados teste de Chi-Quadrado e Teste t de Student e correlação de Spearman. Resultados: Foram estudados 65 pacientes com asma, dos quais 53 tiveram sua avaliação completa. Trinta e dois pacientes apresentaram percepção da dispnéia (60,5%) quando ocorreu broncoconstrição induzida pela metacolina. Entretanto, 21 pacientes (39,5%) não apresentaram alteração em relação aos sintomas de dispnéia, mesmo com queda de 20% do VEF1. Os grupos dos percebedores e não percebedores não apresentavam diferenças quanto ao VEF1 basal, percentagem de queda do VEF1 e dose de metacolina necessária para broncoprovocação. Não houve correlação significativa entre percepção da dispnéia com idade (p=0,247), sexo (p=0,329), uso de medicação de manutenção (p=0,152), controle da asma (p=0,562), hiper-responsividade brônquica (p=0,082) e gravidade da broncoconstrição aguda (p=0,749). Conclusões: Percentagem significativa dos asmáticos apresenta baixo grau de percepção da broncoconstrição. Os fatores relacionados com a incapacidade de identificação da modificação da função pulmonar não estão bem definidos. Diagnóstico e orientação dos maus percebedores é fundamental para redução de morbidade e mortalidade por asma. / Objective: To assess the percentage of poor perception of dyspnea in asthmatics and its correlation with acute bronchoconstriction severity, airway hyperresponsiveness, medication use and asthma control. Methods: Uncontrolled clinical trial of asthmatics from outpatient department HSL-PUCRS. Methacholine challenge testing was performed with five-breath dosimeter protocol. The perception of airway narrowing after 20% fall in FEV1 was evaluated using the Borg scale. Data concerning demographic information, asthma control, long-term management medication and rescue medication consumption were recorded. Chi-square test and Student´s T test and Spearman’s correlation were applied for the statistical analysis. Results: 65 patients were included and 53 completed the evaluation. 32 patients presented dyspnea (60,5%) when methacholine induced bronchoconstriction occurred but 21 patients (39,5%) did not show any difference related to dyspnea symptoms, even with 20% fall in FEV1. There were no differences between the two groups in terms of the baseline FEV1, % of fall FEV1, and methacoline dose that promoted a positive test. There was no significant association between airway obstruction and age (p= 0.247), sex (p=0.329), long term management medication use (p=0.152), asthma control (p=0.562), airway hyperresponsiveness (p=0.082), and acute bronchoconstriction severity (p=0.749). Conclusion: Significant percentage of astmatics presents poor perception of bronchoconstriction. The identification and orientation of this group of patients is essential to make plans of interventions and eventually reduce asthma morbidity and mortality.

The purpose of this review was to identify the history of and advances in cystic fibrosis (CF). New treatment plans, medication developments, and a historical perspective of airway clearance therapy (ACT) will be presented. The importance of treatment compliance and time management in the care of cystic fibrosis patients will also be discussed. Furthermore, the development of cystic fibrosis clinics and the pivotal role they play in the treatment of the disease will be addressed. Lastly, a brief discussion concerning the need for and process of lung transplantation will be reported.

The airway epithelium has many roles in innate immunity including detection of pathogens and transmitting danger signals to other cell types. However, its role as a primary defender against infection is not well recognized. We have investigated methods of augmenting antiviral immunity by application of agents that stimulate viral killing, either in the extracellular space or within the cytoplasm. A recently described property of airway epithelial cells is direct oxidative killing of bacteria through the coordination of Duox and lactoperoxidase enzymes. We have exploited this property by supplementing airway cells with the lactoperoxidase substrate iodide to prevent viral infection. A second method for enhancing antiviral defenses is to supply small interfering RNAs (siRNAs) targeting essential viral genes. We have optimized antiviral siRNAs targeting respiratory syncytial virus by designing them to specifically target positive sense viral RNAs. Finally, we have initiated a project to discover host defense genes that are expressed in either the submucosal glands surface epithelium of human airway. This information will enable a better characterization of the roles for these structures in host defense pathways, and may identify other targets for augmentation of antiviral immunity.

Acute Respiratory Distress Syndrome (ARDS) is a lung condition with a mortality rate of 40 % that affects about 225,000 individuals in the U.S. In these patients, epithelial injury can contribute to alveolar flooding and injury to type II cells by disrupting normal epithelial fluid transport, impacting the removal of edema fluid from alveolar space. Mechanical stresses associated with opening occluded airways damages the epithelial lining of the lungs. Prior studies explore the nature of the stresses and damage in straight tube models of airways. Our model presented in this work accounts for the branching in the pulmonary airways. We have developed a scalable microfluidic model of pulmonary airway bifurcations for investigation of reopening near the bifurcation as well as the macroscopic reopening pattern. We utilize a μ-PIV/Shadowgraph system to visualize the flow fields near the interface as a semi-infinite finger of air propagates through the bifurcation model. Further, we utilize μ-PIV for downstream flow-rate monitoring to examine the symmetry of reopening through bifurcating networks. In the absence of surfactant, propagation preferentially opens the low-resistance path, and leads to asymmetric reopening. However, with SDS and albumin inactivated surfactant, interfacial propagation preferentially reopens the pathway with the higher hydraulic resistance. The propagation pattern with pulmonary surfactant stabilizes the system so that the daughter branches of a nearly symmetric bifurcation open simultaneously. Our multiple generation network serves to validate the stability of the single generation. However, the second generation does not mirror the behavior of the first generation. We explore the reasons for this, and also present preliminary studies for the investigation of restoring surfactant function after deactivation by serum proteins. / acase@tulane.edu

The airway surface contains a number of important defense mechanisms to protect against infection. Antimicrobials found in the thin layer of fluid lining the airways, the airway surface liquid (ASL), rapidly kill bacteria. Another defense mechanism, mucociliary transport, propels foreign particles and mucus out of the airways. These and potentially other host defense properties show a dependence on the pH of the ASL. An acidic ASL pH reduces bacterial killing by cationic antimicrobial peptides, and increases ASL viscosity, potentially effecting mucociliary transport. Consequently, an acidic ASL pH can impair airway host defense. An example of a disease where an acidic ASL pH impairs airway host defense, is Cystic Fibrosis (CF). The major cause of morbidity and mortality in CF is airway infections. Humans with CF and the CF pig model develop airway infections. But curiously CF mice are spared. Compared to non-CF, people with CF and CF pigs show an abnormally acidic ASL pH. However, the ASL pH in CF mice is not different to that of non-CF. Thus, we hypothesized that CF mice do not show defects in airway host defense because their ASL pH is not acidic compared to non-CF. As pH is a balance between acid and base secretion, we first determined which HCO3- and H+ secreting proteins contribute to ASL pH and the differences between humans, pigs, and mice. CF is caused by defects in an anion channel, CFTR. We found that in all three species, CFTR secreted HCO3- into the ASL, which was absent when CFTR was defective. To determine how much CFTR is required to rescue ASL pH and host defense properties, we mixed CF and non-CF airway epithelia from newborn pigs in different ratios. HCO3- secretion, ASL pH, and host defense properties showed a direct relationship to CFTR, suggesting that CFTR was the rate-limiting step. As CFTR was limiting, we found that supernormal CFTR expression in a small number of cells could dramatically increase ASL pH, suggesting viral-mediated gene therapy approaches may have benefit for CF. We found that Ca2+ activated Cl- channels also played some role in ASL pH in CF pigs and CF mice. However, as CF pigs develop airway infection, while CF mice do not, this suggested that other factors might be important for differences in ASL pH and consequently the development of disease. To further investigate the determinants of ASL pH, we examined H+ secretion. Humans and pigs showed 6 times more H+ secretion compared to mice. This acidification occurred through the non-gastric H+/K+ ATPase (ATP12A). ATP12A was also much more highly expressed in human and pig airways compared to mice. Blocking ATP12A in human and pig airways increased ASL pH and consequently improved host defense properties such as bacterial killing and ASL viscosity. Conversely, expressing ATP12A in CF mouse airways acidified ASL, impaired defenses, and increased airway bacteria. These findings suggest that ASL pH is a balance between HCO3- and H+ secretion. In humans and pigs lacking CFTR, unchecked H+ secretion by the non-gastric H+/K+ ATPase (ATP12A) acidifies the ASL, which impairs airway host defenses. However, as mouse airways expressed little ATP12A and secrete minimal H+, loss of CFTR does not lead to ASL acidification, protecting CF mice. These findings not only help explain why CF mice are protected from infection, but also nominate ATP12A as a therapeutic target for improving ASL pH and host defense in humans with CF.