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Desenvolvimento de um sistema FOT (Técnica de Oscilações Forçadas) e sua aplicação na avaliação da mecânica respiratória / Development of a FOT system (Forced Oscillation Technique) and its application in evaluation of respiratory mechanicsAndrea Fonseca da Cruz 01 December 2016 (has links)
INTRODUÇÃO: A avaliação da mecânica respiratória descreve as propriedades mecânicas do sistema respiratório (SR) através da determinação de índices úteis para avaliar a função pulmonar. Nos pacientes em ventilação mecânica, os métodos mais utilizados são o estático, por meio de pausas em que a resistência inspiratória (RINS) e a elastância estática (EST) são calculadas, e o dinâmico, onde a aplicação da equação do movimento (EM) dos gases estima a resistência (REM) e a elastância (EEM) do SR. Já nos indivíduos atentos e respirando espontaneamente, a espirometria e a pletismografia são as técnicas mais empregadas e a EM também é uma opção. A técnica de oscilação forçada (FOT) possibilita a medição da impedância mecânica do SR e seus componentes resistivos (RFOT), elásticos (EFOT) e inerciais, que têm sido utilizados na avaliação da mecânica respiratória. OBJETIVOS: Desenvolver um sistema FOT e avaliar sua aplicabilidade na monitorização da mecânica respiratória nos pacientes em ventilação mecânica e nos indivíduos em ventilação espontânea. MÉTODOS: Um sistema FOT composto de oscilador, módulo de sinais e softwares de aquisição e processamento foi desenvolvido e validado utilizando modelos mecânicos. Em suínos sob ventilação mecânica, o sistema FOT foi utilizado durante a titulação decrescente da pressão positiva ao final da expiração (PEEP) e a RFOT e EFOT em cada PEEP foi comparada com a REM e EEM. Em pacientes intubados e sob ventilação mecânica, o sistema FOT foi utilizado na PEEP, na pressão média e na pressão de platô do ciclo ventilatório. Nos pacientes a RFOT e EFOT, foram comparadas com a REM e EEM e também com a RINS e a EEST. Nos voluntários, a FOT foi superimposta à respiração espontânea e a RFOT e EFOT foi comparada com a REM e EEM obtidas por meio da pressão transpulmonar. RESULTADOS: A validação do sistema FOT nos modelos mecânicos foi bem-sucedida e resultou em valores próximos dos esperados. Nos seis suínos analisados, as diferenças encontradas entre a FOT e a EM tiveram origem principalmente na variabilidade de cenários e nos valores dos parâmetros fluxo, volume e pressão empregados em cada método. Nos quatro pacientes, as características dos métodos e a variabilidade dos parâmetros ventilatórios explicaram a maior parte das diferenças observadas. Nos quatro voluntários, assim como na literatura, os dados da FOT apresentaram valores maiores que os dados EM, porém, as causas ainda não foram totalmente esclarecidas. CONCLUSÕES: O sistema FOT foi desenvolvido conforme os requisitos de segurança, portabilidade e usabilidade. A impedância mecânica e seus componentes podem ser utilizados na avaliação da mecânica respiratória, mas sua comparação direta com outros métodos não é possível devido as diferenças intrínsecas dos métodos e principalmente pelos distintos valores de fluxo, volume e pressão encontrados em cada um dos métodos / INTRODUCTION: The evaluation of respiratory mechanics describes the mechanical properties of the respiratory system (SR) through the determination of useful indexes to assess lung function. In mechanically ventilated patients, the most commonly used methods are: 1) static, through end-inspiratory and end-expiratory hold maneuvers, the resistance (RINS) and static elastance (EEST) are calculated; 2) dynamic, where the application of the equation of motion (EM) estimates the resistance (REM) and the elastance (EEM) of the SR. In spontaneously breathing individuals, spirometry and plethysmography are the most used techniques and EM is also an option. The forced oscillation technique (FOT) enables the measurement of the mechanical impedance of the SR and its resistive (RFOT), elastic (EFOT) and inertial components that have been used to assess respiratory mechanics. OBJECTIVES: Develop a FOT system and to evaluate its effectiveness in monitoring respiratory mechanics in mechanically ventilated patients and individuals in spontaneous ventilation. METHODS: A FOT system comprising the oscillator, the signal module and software for acquisition and processing were developed and validated using mechanical models. In pigs under mechanical ventilation, the FOT system was used during the positive end-expiratory pressure (PEEP) titration and RFOT and EFOT in each PEEP was compared with REM and EEM. In intubated and mechanically ventilated patients, the FOT system was used at the PEEP, mean pressure and plateau pressure of the ventilatory cycle. In patients, RFOT and EFOT were compared with REM and EEM and also with the RINS and EEST. In volunteers, the FOT was superimposed to the spontaneous breathing and RFOT and EFOT were compared with REM and EEM obtained with the transpulmonary pressure. RESULTS: The validation of the FOT system in the mechanical models was successful and resulted in values close to those expected. In the six pigs tested, the differences between the FOT and EM were due to the variability in the scenarios and in the values of the parameters flow, volume and pressure used in each method. In four patients evaluated, the characteristics of the methods and the variability of ventilatory parameters explained most of the differences observed. In our four volunteers, as well as in literature, the FOT data showed higher values that EM data, however, the causes have not yet been fully clarified. CONCLUSIONS: The FOT system was developed according to the safety, usability and portability requirements. The mechanical impedance and its components can be used to evaluate the respiratory mechanics, but its direct comparison to other methods is not possible due to intrinsic differences between methods and mainly by different values of flow, volume and pressure found in each method
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Tempo de espera para o diagnóstico e tratamento da síndrome da apneia do sono em hospital público brasileiro / Waiting time for the diagnosis and treatment of sleep apnea syndrome in brazilian public hospitalFleig, Alessandra Hofstadler Deiques January 2013 (has links)
Objetivos: Determinar o tempo de espera para o diagnóstico e início do tratamento da síndrome da apneia obstrutiva do sono (SAOS) em hospital público brasileiro. Desenho do estudo: Estudo transversal. Métodos: Foi avaliada, com um questionário específico, uma amostra de conveniência composta por 68 pacientes com síndrome da apneia obstrutiva do sono (SAOS), com indicação de tratamento com pressão positiva em vias aéreas (PAP) e que utilizaram o aparelho durante acompanhamento ambulatorial, no período de janeiro de 2005 a dezembro de 2009. Foram excluídos os pacientes menores de 18 anos, incapazes de responder ao questionário ou que se negaram a participar. Resultados: Dos pacientes avaliados, a maioria era de homens (62%), com média de idade de 54,4 (+ 10,7) anos e obesos (IMC médio 33,7 + 7,1 Kg/m2); 76% eram hipertensos, 22% portadores de diabete melito e igual número de doença arterial coronariana; 10% destes apresentavam hipoventilação associada. A mediana do tempo entre a primeira consulta médica e a realização da PSG diagnóstica foi de 8,3 (intervalos interquartis [IQ] 3,3-14,3) meses e a mediana do tempo da indicação da PAP até a aquisição do aparelho foi de 10,5 (IQ 3,1-16,7) meses. Sessenta e quatro pacientes (94%) eram usuários de CPAP e 4 usuários de bilevel (6%). A maioria dos aparelhos (57%) foi obtida de forma gratuita por meio da rede pública de saúde. Conclusão: O presente estudo evidenciou a demora excessiva para diagnóstico e tratamento dos pacientes portadores de SAOS em atendimento em um hospital público de referência no Brasil. / Objectives: To determine the waiting time for the diagnosis and beginning of treatment of syndrome of obstructive sleep apnea (OSA) in Brazilian public hospital. Study design: cross-sectional study Methods: A convenience sample composed of 68 patients with syndrome of obstructive sleep apnea (OSA) was assessed through a specific questionnaire. All patients were indicated a treatment with positive airway pressure (PAP) and that used the unit during de period between January 2005 and December 2009. Patients who were under 18 years old, who were uncapable of answering the questionnaire or who refused to answer were excluded. Results: Among the patients, the majority were men (62%), with an average age of 54.4 (+10.7) years and obese (mean BMI 33.7 + 7.1 kg/m2); 76% were hypertensive, 22% diabetes mellitus patients and an equal number with coronary artery disease, 10% of them had associated hypoventilation. The average time between the first medical consultation and the implementation of diagnostic PSG was 8.3 (interquartile range [IQ] 3.3 to 14.3) months and the average time indication of the PAP until the purchase of the equipment was 10,5 (CI 3.1 to 16.7) months. Sixty-four patients (94%) were users of CPAP and 4 were users of bilevel (6%). Most appliances (57%) were obtained free of charge through the public health system. Conclusion: The present study demonstrated the excessive delay to diagnosis and treatment of patients with OSAS in attendance at a public hospital of reference in Brazil.
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A ventilação não invasiva como uma opção de suporte ventilação para pacientes pediátricos em pós-operatório de cirurgia cardíaca com insuficiência respiratória / Use of non-invasive ventilation in extubation failure at the post-operative care in pediatricsRolim, Denise de Souza 06 April 2018 (has links)
Objetivos: determinar a taxa de falha da ventilação não invasiva (VNI) em crianças em pós operatório (PO) de cirurgia cardíaca com insuficiência respiratória (IResp) pós extubação e identificar seus fatores preditivos de sucesso. Tipo de estudo: coorte prospectivo. Local: Unidade de terapia intensiva pediátrica de três hospitais terciários de São Paulo, Brasil. Sujeitos: Pacientes consecutivos pediátricos menores que 18 anos com diagnóstico de cardiopatia congênita que foram submetidos a cirurgia cardíaca corretiva ou paliativa e apresentaram IResp em até 48 horas após a extubação sendo tratados com VNI. Intervenção: nenhuma. Métodos e resultados principais: a coleta de dados foi realizada entre 2011 e 2014, analisados 170 pacientes. Foi considerado falha da VNI a necessidade de reintubação orotraqueal em até 48 horas após o término do uso da VNI. Nenhum paciente apresentou parada cardiorrespiratória durante o uso da VNI, nem outra complicação que interrompesse seu uso. 61,8% tiveram sucesso na utilização de VNI, não necessitando de reintubação. A mediana de idade foi de 2 meses. Os sujeitos foram divididos em grupo sucesso da VNI e falha para a análise. A análise estatística foi realizada com os testes qui-quadrado, Mann-Whitney ou testes t-Student, realizada após a regressão logística univariada e multivariada para os com p < 0,05. As seguintes variáveis não apresentaram diferença estatística, entre os grupos: tempo circulação extracorpórea (p=0,669), hipertensão pulmonar (p=0,254), síndrome genética (p=0,342), RACHS-1 (p=0,097), idade (p=0,098), tempo ventilação mecânica invasiva (VMI) (p=0,186) e tempo VNI (p=0,804). O sexo masculino apresentou maior incidência de sucesso da VNI com p=0,013. Todos os parâmetros ventilatórios utilizados na VNI foram coletados e apresentaram p < 0,05. Na análise multivariada, apenas influenciaram na ocorrência de falha da VNI o gradiente de pressão mínimo (OR 1,45 com p=0,007), a saturação de pulso de oxigênio (SpO2) máxima (OR 0,88 com p=0,011) e a fração inspirada de oxigênio (FiO2) máxima (OR 1,16 com p < 0,001). Conclusão: VNI pode ser utilizada com sucesso em crianças em PO de cirurgia cardíaca que desenvolveram IResp nas 48 horas subsequentes à extubação, utilização de maior gradiente de pressão e maiores FiO2 são fatores associados com maior falha da utilização da VNI, utilização da VNI é segura sem a ocorrência de eventos adversos que impossibilitassem a utilização desta terapêutica / Objectives: To determine the rate of failure of noninvasive ventilation (NIV) in postoperative (PO) cardiac surgery in pediatric patients with respiratory failure (RF) after extubation and to identify predictive success factors. Design: prospective cohort study. Setting: Pediatric intensive care unit of three tertiary hospitals in São Paulo, Brazil. Patients: Consecutive pediatric patients under 18 years of age with diagnosis of congenital heart disease who underwent corrective or palliative heart surgery and presented RF within 48 hours after extubation and were treated with NIV. Intervention: none. Measurements and main results: data collected between 2011 and 2014, from 170 patients with 2 months median age. The need for orotracheal reintubation within 48 hours after the end of NIV was considered as NIV failure. No patient presented cardiorespiratory arrest during the use of NIV, nor another complication that interrupted its use. Overall, 61.8% were successful in the use of NIV, not requiring reintubation. Subjects were divided for analysis into successful and failed NIV groups. Statistical analysis used chi-square, Mann-Whitney or Student-t tests, performed after univariate and multivariate logistic regression, for p < 0.05. In the multivariate analysis, only the minimal pressure gradient (OR 1.45 with p = 0.007), the maximum oxygen saturation (SpO2) (OR 0.88 with p = 0.011) and the maximum inspiratory oxygen fraction (FiO2) (OR 1.16 with p < 0.001) influenced NIV failure. All ventilatory parameters used in NIV were collected and affected NIV success, with p < 0.05. The following variables did not present statistical difference between the groups: extracorporeal circulation time (p = 0.669), pulmonary hypertension (p = 0.254), genetic syndrome (p = 0.342), RACHS-1 (p = 0.097), age (p = 0.098), invasive mechanical ventilation (IMV) duration (p = 0.186) and NIV duration (p = 0.804). Conclusion: NIV can be successfully used in children in cardiac surgery postoperative who developed RF in the 48 hours following extubation. Use of higher pressure gradients and higher FiO2 associate with greater failure of NIV use. NIV use is safe, without occurrence of adverse events that prevent its use
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Avaliação das vias aeríferas superiores, antes e após expansão rápida da maxila, utilizando Tomografia Computadorizada por Feixe Cônico / Assessment of upper airway before and after rapid maxillary expansion using Cone Beam Computed TomographyRibeiro, Annelise Nazareth Cunha 03 June 2011 (has links)
A respiração predominantemente oral é constantemente citada como um dos fatores associados ao desenvolvimento da deficiência transversal da maxila. A Expansão Rápida da Maxila (ERM) é um excelente método para a correção desta alteração, por meio da abertura da sutura palatina. A tomografia computadorizada por feixe cônico é tem sido descrita como um método preciso de exame de imagens e diante das limitações dos métodos radiográficos convencionais o objetivo deste estudo é avaliar as alterações morfológicas imediatas, decorrentes da ERM, na cavidade nasal e na região da naso e orofaringe, por meio da TCFC. Foram avaliadas 15 pares de imagens tomográfica, correspondentes a 15 pacientes portadores deficiência transversal da maxila, tratados com ERM, que realizaram a TCFC ao início e após o período de contenção de 4 meses. Os resultados encontrados mostram que a cavidade nasal apresenta aumento transversal significativo em seu terço inferior, nas regiões anterior (p=0,045), média (p=0,009) e posterior (p=0,001). Não há alteração significativa do volume (p=0,11), área sagital mediana (p=0,33) e menor área axial (p=0,29) decorrente da ERM na nasofaringe. Há alteração significativa do volume (p=0,05), área sagital mediana (p=0,01) e menor área axial (p=0,04) nos momentos antes e imediatamente após a ERM, na orofaringe. Após análise dos resultados concluímos que a ERM é capaz de aumentar a largura transversal da cavidade nasal, não tendo o mesmo efeito na região da nasofaringe, e que as alterações encontradas na orofaringe podem ser decorrentes de falta de padronização o posicionamento da cabeça e lingual no momento da aquisição da imagem. / The predominantly oral breathing is constantly cited as an etiological factor for the transverse maxillary deficiency. Rapid Maxillary Expansion is an excellent method for the correction of malocclusion, through the opening of the midpalatal sutures. The literature shows that the benefits of this procedure are beyond the dental benefits, and could have repercussions in the upper airways, due to its close relationship with the maxilla. The cone beam computed tomography has been described as is an accurate method of taking pictures and before the limitations of conventional radiographic methods the aim of this study is to evaluate the immediate morphological changes resulting from the ERM, the nasal cavity and the nasal region and oropharynx, through the CBCT. We evaluated 15 patients with maxillary width deficiency were treated with RME, which hosted the CBCT to the beginning and after the retention period of 3 months. The results show that the nasal cavity presents significant increase in cross their lower third, in the anterior (1.08 mm ± 0.15), medium (1.28 mm ± 0.15) and posterior (0.77 mm ± 0.12). No significant change in volume (p=0.11), median sagittal area (p=0.33) and lower axial area (p=0.29) resulting from the RME in nasopharynx. There is significant change in volume (p = 0.05), median sagittal area (p = 0.01) and lower axial area (p = 0.04) before and immediately after the RME in the oropharynx. After analysis and discussion of results in this study, we concluded that RME is able to increase the transverse width of the nasal cavity, not having the same effect in the nasopharynx, and that the changes found in the oropharynx may be due to the lack of positioning standardization of the head and tongue at the time of image acquisition.
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A numerical study of periciliary liquid depth in MDCT-based human airway modelsWu, Dan 01 May 2015 (has links)
Periciliary liquid (PCL) is a critical component of the respiratory system for maintaining mucus clearance. As PCL homeostasis is affected by evaporation and mechanical forces, which are in turn affected by various breathing conditions, lung morphology and ventilation distribution, the complex process of PCL depth regulation in vivo is not fully understood. We propose an integrative approach to couple a thermo-fluid computational fluid dynamics (CFD) model with an epithelial cell model to study the dynamics of PCL depth using subject-specific human airway models based on multi-detector row computed-tomography (MDCT) volumetric lung images.
The thermo-fluid CFD model solves three-dimensional (3D) incompressible Navier-Stokes and transport equations for temperature and water vapor concentration with a realistic energy flux based boundary condition imposed at airway wall. A corresponding one-dimensional (1D) thermo-fluid CFD model is also developed to provide necessary information to the 3D model. Both 1D and 3D models are validated with experimental measurements, and the temperature and humidity distributions in the airways are investigated. Correlations for the dimensionless parameters of Nusselt number and Sherwood number are proposed for characterizing heat and mass transfer in the airways. As one of the key applications of the thermo-fluid CFD model, the water loss rates in the both 1D and 3D airway models are studied. It is found that the secondary flows formed at the bifurcations elevate the regional heat and mass transfer during inspiration and hence the water loss rate, which can only be observed in the 3D models. Among the three human airway models studied in both 1D and 3D, little inter-subject variability is observed for the distributions of temperature and humidity. However, the inter-subject variability could be dramatic for the distribution of water loss rate, as it is greatly affected by airway diameter and regional ventilation.
A method is proposed to construct an ion-channel conductance model for both normal and cystic fibrosis (CF) epithelial cells, which couples an existing fluid secretion model with an existing nucleotide and nucleoside metabolism model (collectively named epithelial cell model). The epithelial cell models for both normal and CF are capable of predicting PCL depth based on mechanical stresses and evaporation, and are validated with a wide range of experimental data.
With these two models separately validated and tested, the integrated model of the thermo-fluid CFD model and epithelial cell model is applied to MDCT-based human airway models of three CF subjects and three normal subjects to study and compare PCL depth regulation under regular breathing conditions. It is found that evaporative water loss is the dominant factor in PCL homeostasis. Between three types of mechanical forces, cyclic shear stress is the primary factor that triggers ATP release and increases PCL depth. In addition, it is found that that greater diameters of the airways in the 4th-7th generations in CF subjects decrease evaporative water loss, resulting in similar PCL depth as normal subjects. Under regular breathing conditions, the average PCL depths of normal and CF is around 6 to 7 µm, with mechanical forces play a greater role in regulating CF PCL depth. Comparing to 7.68 µm normal base level (considered as optimum PCL depth), this average PCL depth is about 8 to 21% lower. This might suggest that mechanical forces alone cannot entirely balance evaporative water loss, and other mechanisms might be involved.
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Virtual reality for the characterization of blood vessel to airway geometric relationshipsAbdelraouf, Mostafa 01 January 2018 (has links)
An increase in the cross-sectional area (CSA) of the pulmonary arteries has been implicated in the progression of emphysema in COPD patients. Standardization of vessel size requires matching segments of the airway with their corresponding blood vessels. Automated matching is still error-prone, and manual matching by sifting through 2D slices is tedious and time-consuming. We propose a virtual reality (VR) system for the visualization of the airway and the vascular tree as a means of streamlining the verification of appropriate airway/vascular segment pairs selected for quantitation of arterial CSAs. In this work, we outline the technical specifications and design considerations and challenges for such system; we also compare user's performance on the proposed system with the conventional 2D method.
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The control of respiration and upper airway muscle activity in healthy young men and women / by Amy Jordan.Jordan, Amy Selina January 2002 (has links)
"May 2002." / Bibliography: leaves 123-144. / xiv, 144 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Aspects of the control of ventilation and an upper airway dilator muscle (genioglossus) are compared between healthy men and women, in an attempt to identify a gender difference that may contribute to the high male prevalence of sleep apnea. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physiology, 2002
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Hedgehog signalling in lung development and airway regenerationUda Ho Unknown Date (has links)
Tumorigenesis is often caused by the dysregulation of developmental pathways that are activated during repair, a process that recapitulates development. The Hedgehog (Hh) pathway is a signalling pathway essential for cell patterning and identity during embryogenesis. Activation of Hh signalling has been reported in small cell lung cancer progression, but the role of the Hh receptor, Patched1 (Ptch1), remains poorly understood. Therefore, it is imperative that we understand how Ptch1 is involved in development and tissue repair in order to understand its roles in cancer. This project aimed to study the role of Ptch1 during the branching process of lung development and in the regeneration of airway epithelial cells. A conditional knockout approach was utilised to excise Ptch1 by crossing Ptch1 conditional mice with Dermo1-Cre mice (Dermo1Cre+/-;Ptch1lox/lox), thereby activating the Hh pathway in the mesenchyme, independent of ligand. Dermo1Cre+/-;Ptch1lox/lox embryos died at E12.0 and showed secondary lung branching arrest leading to lobe formation defects. Expression of Ptch1, Gli1 and Foxf1 were shown to be upregulated in both proximal and distal lung mesenchyme, indicating inappropriate pathway activation and disruption of the Hh gradient. Fgf10 expression was spatially reduced in Dermo1Cre+/-;Ptch1lox/lox lungs and the addition of Fgf10 to these lungs in culture showed partial restoration of branching, thus Hh signalling was shown to regulate branching via Fgf10. Due to the patterning defect associated with our in vivo model, we took an in vitro approach to delete Ptch1 in lung explants cultures. This also showed reduced branching and validated that mesenchymal proliferation was enhanced after Ptch1 deletion, consistent with the previously reported role of Hh signalling in mesenchymal cell survival. Small cell lung cancer originates in the proximal lung and has been linked to aberrant repair processes. Therefore, Hh signalling in proximal airway repair was investigated. Ptch1 expressing cells were detected in the bronchial epithelium and stroma during homeostasis. But these cells were not detected following polidocanol-induced injury in the murine nasal septum and lung. However during naphthalene-induced repair, Ptch1 expressing cells were detected in the regenerating bronchial epithelium, suggesting that Hh dependent progenitors respond specifically to naphthalene-induced damage and perhaps are pulmonary neuroendocrine or variant Clara cells. Therefore, this project has provided insight into how Ptch1 patterns lung branching and lobe specification during development and also highlights the importance of Ptch1 in pulmonary epithelial regeneration.
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Towards Pharmacological Treatment of Cystic FibrosisAndersson, Charlotte January 2002 (has links)
<p>S-nitrosogluthatione is an endogenous substance, present at decreased levels in the lungs of CF patients and was recently found to induce mature CFTR in airway epithelial CF cell lines. We show that S-nitrosoglutathione in physiological concentrations increases the presence of ΔF508 CFTR in the cell membrane and induces cAMP dependent chloride transport in cystic fibrosis airway epithelial cells. The properties of S-nitrosoglutathione include other potential benefits for the CF patient and make this agent an interesting candidate for pharmacological treatment of CF that needs to be further evaluated.</p><p>Genistein was found to increase the chloride efflux in both normal and ΔF508 cells without stimulation of cAMP elevating agents and without prior treatment with phenylbutyrate. Genistein, in concentrations close to those that can be detected in plasma after a high soy diet, could induce chloride efflux in cells with the ΔF508 CFTR mutation and its possible use in the treatment of CF should therefore be further investigated.</p><p>Studies on nasal epithelial cells from CF patients showed cAMP dependent chloride efflux in some of the patients with severe genotypes. This may complicate <i>in vitro</i> evaluation of clinical treatment of these patients. The presence of cAMP dependent chloride transport did not necessarily lead to a milder phenotype. Other factors than CFTR may influence the clinical development of the disease.</p><p>Cystic fibrosis (CF) is the most common monogenetic disease among Caucasians. A defective cAMP regulated chloride channel (cystic fibrosis transmembrane conductance regulator, CFTR) in epithelial cells leads to viscous mucus, bacterial infections, inflammation and tissue damage in the lungs that cause death in 95% of the cystic fibrosis patients. There is no cure for the disease although existing treatment has dramatically prolonged the life expectancy. The aim of this thesis was to study pharmacological agents for their ability to restore the cellular deficiency in CF airway epithelial cells. X-ray microanalysis, MQAE fluorescence and immunocytochemistry were used to evaluate the effects.</p>
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Approaches to Pharmacological Treatment and Gene Therapy of Cystic FibrosisDragomir, Anca January 2004 (has links)
<p>Cystic fibrosis (CF) is the most common lethal genetic disease in the white population. It is due to mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR), a protein that functions mainly as a cAMP-activated chloride channel. The disease impairs ion and water transport in epithelia-lined organs such as airways, digestive tract, reproductive epithelium and sweat glands. At present the only therapy is symptomatic and development of curative treatment depends on uncovering the links between the defective CFTR and the disease, as well as on improving end-point measurements. </p><p>A method has been established for studying ion transport in an easily accessible cell type (nasal epithelial cells) from normal and cystic fibrosis patients by X-ray microanalysis. This method represents a rather simple and direct way of measuring simultaneously several chemical elements of biological interest.</p><p>Studies of chloride transport by means of a fluorescent indicator (MQAE) in nasal epithelial cells from CF patients showed that the phenotype cannot exclusively be explained by the CFTR activity in patients with severe genotype. </p><p>A common Portuguese CFTR mutation (A561E) causes protein mislocalization in the endoplasmic reticulum similar to the most common CF mutation (ΔF508) and thus it should be possible to treat it with the same pharmacological strategies.</p><p>Chronic treatment of CF airway epithelial cells with nanomolar concentrations of colchicine increased the chloride efflux via chloride channels other than CFTR, strengthening the notion that colchicine could be beneficial to CF patients.</p><p>Successful <i>in vitro </i>transfection of CF airway epithelial cells with cationic vectors was possible with short incubation times. Heparin added at the end of the transfection incubation time could help to maintain the viability of the cells, without interfering with the transfection efficiency. It seems possible that heparin could be an adjuvant for non-viral mediated gene therapy.</p>
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