O objetivo do presente estudo foi avaliar o efeito do suporte ventilatório com ventilação assistida proporcional (PAV) na capacidade ao exercício em pacientes com fibrose pulmonar idiopática (FPI). Dez pacientes foram submetidos a um teste cardiopulmonar de esforço máximo, prova de função pulmonar completa e 3 testes submáximos (60% da carga máxima): sem suporte ventilatório, com pressão positiva contínua nas vias aéreas (CPAP) e PAV. Foram avaliadas a capacidade de exercício, as adaptações cardiovasculares e ventilatórias e a percepção subjetiva de esforço. Uma amostra de lactato sanguíneo foi também obtida no repouso e no final do exercício. Nossos resultados mostram que a capacidade de exercício submáximo com suporte ventilatório PAV aumentou o tempo de exercício quando comparado com a CPAP e sem suporte ventilatório (respectivamente, 11,10±8,88 min, 5,60±4,74 e 4,50±3,84 min). O suporte ventilatório com PAV ocasionou uma menor demanda cardiovascular com redução do duplo produto e da freqüência cardíaca. Uma melhor oxigenação e uma menor percepção de esforço também foram observadas nos pacientes quando realizaram a atividade com PAV. Nossos resultados sugerem que o suporte ventilatório com PAV pode aumentar a tolerância ao exercício e reduzir a dispnéia em pacientes com fibrose pulmonar idiopática. / The objective of the present study was to evaluate the effect of ventilatory support using proportional assist ventilation (PAV) on exercise capacity in patients with idiopathic pulmonary fibrosis. Ten patients were submitted to a cardiopulmonary exercise testing, lung function and 3 submaximal exercise tests (60% of maximum load): without ventilatory support, with continuous positive airway pressure (CPAP) and PAV. Exercise capacity, cardiovascular and ventilatory adaptations and subjective perception to effort in lower limb and respiratory breathing were evaluated. Lactate plasmatic levels were obtained before and after submaximal exercise. Our results show that submaximal exercise capacity duration was increased with PAV compared with CPAP and without ventilatory support. (respectively, 11.10±8.88 min, 5.60±4.74 e 4.50±3.84 min). Ventilatory support with PAV lead to a lower cardiovascular demand such as double product and heart rate decreased. An improved arterial oxygenation and lower subjective perception to effort was also observed in patients with IPF when exercise was performed with PAV. Our results suggest that ventilatory support with PAV can increase exercise tolerance and decrease dyspnea in patients with idiopathic pulmonary fibrosis.

Objetivos: A FCL é um novo padrão de doença intersticial pulmonar idiopática associado ao refluxo gastro-esofágico. Nós investigamos sua presença na ES com envolvimento pulmonar. Métodos: 28 pacientes com ES foram submetidos à biópsia pulmonar a céu aberto. As amostras foram classificadas conforme o novo consenso de classificação das pneumonias intersticiais idiopáticas e de acordo com os critérios do padrão FCL. Tomografia computadorizada de alta resolução (TCAR) de tórax, prova de função pulmonar (PFP), esofagograma de contraste e/ou endoscopia digestiva alta também foram realizadas. Resultados: Na ES, o padrão NSIP (67,8%) e a FCL (75%) foram os padrões mais freqüentemente encontrados e na maioria dos casos, eles co-existiam. Todos, exceto um paciente com FCL tinha a característica distribuição broncocêntrica das lesões, sendo mais extensa nos casos com FCL isolada (p=0,001). Da mesma forma, o conteúdo basofílico foi mais freqüente nos pacientes com FCL e completamente ausente no grupo NSIP (p<0,001). Na TCAR, a distribuição central do envolvimento pulmonar foi o achado mais prevalente nos pacientes com FCL isolada (57,14%) contrastando com a 10 predominância do padrão periférico nos outros grupos (p=0,02). Além disso, uma tendência quanto à distribuição segmentar na TCAR foi observada no grupo com FCL isolada (85,71%) e FCL+NSIP (71,43%), enquanto que 80% dos pacientes com NSIP tinham uma distribuição difusa das lesões pulmonares (p=0,08). Anormalidades esofágicas foram um achado quase universal. Conclusão: Está é a primeira descrição de fibrose centrilobular em pacientes com ES e envolvimento pulmonar. Este padrão tem características histológicas e tomográficas distintas e a identificação deste subgrupo de pacientes irá certamente contribuir para uma melhor abordagem terapêutica. / Objectives: CLF is a new histological pattern of idiopathic ILD associated to esophageal reflux. We have investigated its presence in SSc with lung involvement. Methods: 28 SSc patients were submitted to open lung biopsy. The specimens were classified according to the new consensus classification of idiopathic interstitial pneumonia and to the diagnostic criteria for CLF. High Resolution Computer Tomography (HRCT), Pulmonary Function Tests (PFT), contrast esophagogram and/or upper digestive endoscopy were also performed. Main Results: In SSc, the NSIP (67.8%) and the centrilobular (75%) patterns were the most frequent and in the majority of the cases, they co-existed. All, except one patient with CLF had the characteristic bronchocentric distribution and this lesion was more extensive in those with isolated CLF (p=0.01). Likewise, the basophilic content was more frequent in patients with CLF and completely absent in NSIP group (p<0.001). The central distribution of lung involvement on HRCT was the most prevalent finding in patients with isolated CLF (57.14%) contrasting with the predominant peripheral pattern in the other groups (p=0.02). Moreover, a trend towards a patchy distribution on HRCT was observed for CLF group (85.71%) and CLF+NSIP group (71.43%) whereas 80% of the NSIP group had diffuse distribution (p=0.08). Esophageal abnormalities were almost a universal finding. Conclusions: This is the first report of centrilobular fibrosis in SSc patients with lung involvement. This new pattern has distinct histological and tomographic features. The identification of this subgroup of patients will certainly contribute for a more appropriate therapeutic approach.

Selecionamos consecutivamente 63 pacientes com doença mista do tecido conectivo (DMTC) (Kasukawa, 87) para determinar a relevância do padrão SD. Ter uma capilaroscopia periungueal (CPU) até cinco anos antes do início do estudo foi o principal critério de inclusão. Na entrada, avaliamos o envolvimento de órgãos e os auto-anticorpos. A idade média e o tempo de doença foram 45,3 + 10 e 8,45 + 5,42 anos, respectivamente. O padrão SD foi observado em 41 pacientes na entrada (65%) e em 45 na CPU prévia (71,5%), p = 0,20. Dez pacientes (16%) alteraram a CPU, 7 normalizaram e 3 desenvolveram padrão SD. O tempo de doença, número e freqüência de órgãos envolvidos foram semelhantes em pacientes com e sem padrão SD. Em contraste, a análise de cada parâmetro do padrão SD mostrou uma freqüência significativamente menor de áreas avasculares (AA) moderadas/graves na entrada, comparada com a CPU anterior (26,5 e 53%, p = 0,013). Além disto, 76% dos pacientes com doença intersticial pulmonar (TCAR) tiveram AA na entrada, enquanto apenas 24% dos pacientes com esta alteração não apresentavam este achado à CPU (p = 0,017). Adicionalmente, reduzida densidade capilar foi freqüentemente observada em pacientes submetidos à terapia imunossupressora, quando comparados com o grupo sem este tratamento (66,7 e 33,3%, p = 0,001). A CPU na DMTC é um processo dinâmico e a análise de cada parâmetro do padrão SD parece ser um bom indicador de doença intersticial pulmonar e gravidade de doença. / For determining the clinical relevance of SD-pattern in MCTD, sixty-three MCTD patients (Kasukawa´s criteria) were consecutively selected. The main inclusion criterion was availability of previous nailfold capillaroscopy (NC) 5 years before inclusion. At entry, organ involvement and autoantibody evaluation were performed. The mean age and disease duration were 45.3 + 10 and 8.45 + 5.42 years, respectively. SD-pattern was observed in 41 patients at entry (65%) and in 45 at previous NC (71.5%), p = 0.20. Ten patients (16%) changed NC, 7 normalized, and 3 developed SD-pattern. Disease duration, number and frequency of organ involvement were similar in patients with and without SD-pattern. In contrast, analysis of each SD-pattern parameter revealed a significant lower frequency of moderate/severe avascular areas (AA) at entry compared to previous examination (26.5 vs. 53%, p = 0.013). Moreover, 76% of patients with interstitial lung disease (HRCT) had AA at entry, whereas only 24% of patients with this alteration did not have this NC finding (p = 0.017). Furthermore, reduced capillary density was frequently observed in patients taking immunosuppressive therapy than those without (66.7 vs. 33.3%, p = 0.001). NC in MCTD is a dynamic process and analysis of each SD-pattern parameter seems to be a good indicator of lung involvement and disease severity

Estudou-se por morfologia, morfometria e imuno-histoquímica o remodelamento vascular (moléculas de adesão), epitelial (moléculas de adesão) e intersticial (colágeno V e células imunes) nos três tipos maiores de pneumonias intersticiais idiopáticas: em 62 casos de IPF, 22 casos de NSIP e 25 casos de AIP. O impacto dessas alterações foi avaliado nas provas de função, sobrevida e prognóstico. Demonstrou-se que o remodelamento vascular ativo e fibroelastótico é diretamente proporcional ao grau de atividade parenquimatosa principalmente na UIP. O colágeno V, o mapeamento das células imunes, o aumento da atividade endotelial e epitelial tiveram impacto no espectro diferencial e possivelmente na patogênese das três pneumonias intersticiais estudadas. A resposta imune celular na UIP teve impacto na sobrevida dos pacientes / Studied for morphology, morphometry and immunohischemistry the vascular (adhesion molecules), epithelial (adhesion molecules) and interstitial (collagen V and immune cells) remodeling in the three major types of idiopathic interstitial pneumonias: in 62 cases of IPF, 22 cases of NSIP, and 25 cases of AIP. The impact of these alterations was evaluated in the function tests, survival and prognostic. We demonstrated that the active and fibroelastotic vascular remodeling is directly proportional to the degree of parenchymal activity, mainly in the UIP. Collagen V, mapping of the immune cells, increase of the endothelial and epithelial activity had possibly impact in the distinguishing specter and in pathogenesis of the three interstitial pneumonias studied. The cellular immune reply in the UIP it had impact in survival of the patients

Introdução: Alterações pulmonares podem ocorrer no lúpus eritematoso sistêmico juvenil (LESJ) e estar relacionadas com a morbidade e mortalidade. Os objetivos deste estudo foram analisar a função pulmonar de pacientes com LESJ e identificar possíveis correlações com escore da tomografia de alta resolução (TCAR) do tórax, escore de atividade da doença, dano cumulativo da doença e qualidade de vida dos pacientes. Métodos: Quarenta pacientes com LESJ, de 7,4 a 17,9 anos (mediana: 14,1 anos), foram submetidos a espirometria e pletismografia. Difusão de monóxido de carbono (DLCO), TCAR do tórax, teste da caminhada de 6 minutos (TC6M), atividade da doença, dano cumulativo da doença e qualidade de vida também foram avaliados. Resultados: Alterações subclínicas foram observadas em 19/40 (47,5%) pacientes com LESJ na espirometria/DLCO. O volume expiratório forçado no primeiro segundo (VEF1%) foi o parâmetro mais afetado (30%). A TCAR de tórax estava alterada em 22/30 (73,3%) pacientes, sendo alterações mínimas em 43%. Sinais de envolvimento de vias aéreas foram observados em 50% dos casos. Doze pacientes (30%) foram hospitalizados por complicações pulmonares decorrentes do LESJ, com alta hospitalar há pelo menos 11 meses antes do início do estudo (mediana da alta: 2,1 anos). Capacidade pulmonar total (CPT%), capacidade vital (CV%), capacidade vital forçada (CVF%) e VEF1% foram menores no grupo que foi hospitalizado quando comparado com o grupo sem hospitalização por complicações pulmonares (p < 0,05). Houve correlação entre o escore da TCAR com VEF1/VC (r=-0.63; p=0.0002), VEF1 (r=-0.54; p=0.018), FEF25-75% (r=-0.67; p < 0.0001) e resistência das vias aéreas (r=+0.49; p=0.0056). A DLCO apresentou correlação com o tempo de doença (r=+0.4; p=0.01). Conclusão: Aproximadamente metade dos pacientes com LESJ apresentaram alterações funcionais significativas independentemente da atividade da doença e do dano cumulativo. Alterações de vias aéreas foram predominantes, especialmente na TCAR. A correlação positiva entre a DLCO e duração da doença provavelmente está relacionada com a melhora decorrente do tratamento. Complicações pulmonares decorrentes do LESJ podem determinar dano funcional / Introduction: Pulmonary abnormalities can occur in childhood-onset systemic lupus erythematosus (cSLE) and can affect both morbidity and mortality. The aims of this study were to analyze the pulmonary function of cSLE patients and to identify possible correlations with the high-resolution computed chest tomography (HRCT) score, disease activity, disease cumulative damage and the participants\' quality of life. Methods: Forty cSLE patients, median age: 14.1 years (range: 7.4-17.9), underwent spirometry and plethysmography. Carbon monoxide diffusing capacity (DLCO), HRCT, 6-minute walk test (6MWT), disease activity, disease cumulative damage and quality of life were assessed. Results: Subclinical abnormalities were evident in 19/40 (47,5%) cSLE patients according to spirometry/DLCO. Forced expired volume in one second (FEV1%) was the parameter most affected (30%). The HRCT showed some abnormality in 22/30 patients (73,3%), which were minimal in 43%. Signs of airway affection were found in 50%. Twelve patients (30%) were hospitalized due to cSLE-related pulmonary complications, at least 11 month before the study began (median discharge: 2.1years earlier). Total lung capacity (TLC%), vital capacity (VC%), forced vital capacity (FVC%), and FEV1% were lower in the group with hospitalization (p < 0.05). The HRCT-score was correlated with FEV1/VC (r=-0.63; p=0.0002), FEV1 (r=-0.54; p=0.018), FEF25-75% (r=-0.67; p < 0.0001), and resistance (r =+ 0.49; p=0.0056). DLCO was correlated with disease duration (r =+ 0.4; p=0.015). Conclusions: Almost half of patients with cSLE exhibited significant functional abnormalities, regardless of the disease activity and disease cumulative damage. Airway abnormalities were predominant, especially in the HRCT. The positive correlation between DLCO and duration of disease is most likely related to improvement resulting from treatment. The cSLE-related pulmonary complications can determine functional damage

Positive associations between short-term exposure to ambient particulate matter (PM) pollution and cardio-respiratory morbidity and mortality have been established in epidemiologic studies. However, scientific uncertainties remain regarding which PM constituents and sources are most harmful to the exposed population. While tentative evidence of positive links between certain PM constituents and sources with specific health outcomes exists, significant heterogeneity in study findings remains. The chemical composition and emission source of air pollution vary not only temporally, but also geographically. Thus, substantial research on these characteristics under different atmospheres (e.g., Asian atmosphere) is warranted to enhance our understanding of PM-related health effects. / In Hong Kong, air pollution levels often exceed the World Health Organization’s air quality guidelines, posing serious public health threat. Although two decades of active research have associated PM mass (weights) concentration in Hong Kong with elevated risk of daily mortality and emergency hospital admissions, individual chemical constituents and sources responsible for the adverse health effects associated with PM mass have rarely been examined. This thesis attempted to reduce the current scientific uncertainty by making use of the speciation data for PM with aerodynamic diameter ≤ 10 μm (PM₁₀) to examine the associations between chemical constituents and daily cardio-respiratory emergency hospital admissions in Hong Kong between 2001 and 2008. It also capitalized on Positive Matrix Factorization (PMF) source apportionment model to create an alternative measure of PM concentrations that quantified the relative contribution of PM₁₀ sources. This enabled the assessment of health risks associated with exposure to particle mixture from specific sources. / Time-series analyses conducted in this work showed evidence of positive links of emergency hospitalizations with multiple PM₁₀ constituents for various exposure lags examined. In multipollutant models adjusting for gaseous co-pollutants, three groups of constituents were significantly associated with increased risk of cause-specific hospitalizations. They included: combustion-related constituents (i.e., elemental carbon, organic matter, potassium ion, manganese, nitrate ion, arsenic, lead), sea salt-related constituents (i.e., sodium ion, chloride ion, magnesium), and constituents related to soil/road dust (i.e., aluminum, iron). Significant associations were most evident between November to April. PMF model identified eight PM₁₀ sources: 1) vehicle exhaust, 2) soil/road dust, 3) regional combustion, 4) residual oil, 5) fresh sea salt, 6) aged sea salt, 7) secondary nitrate, and 8) secondary sulfate. Health effect analysis demonstrated that all PM₁₀ sources, except fresh sea salt, were positively associated with emergency hospitalizations. Combustion-related sources were positively associated with risk of cardiovascular hospitalizations at shorter cumulative lags than with respiratory hospitalization. Sources that primarily generate coarser particles (i.e., soil/road dust and aged sea salt) were linked to respiratory hospitalizations at shorter cumulative lags than combustion sources that emit fine particles, which were associated with respiratory hospitalization at delayed cumulative lags. / This work may help prioritize future toxicological research on the biologic mechanisms linking PM pollution to cardio-respiratory health. It also stresses the importance of regulation and reduction of traffic and other combustion-related emissions, reconfiguration of urban environment to reduce personal exposure to traffic emissions, as well as establishment of a coordinated and robust regional-scale air quality management plan. Constituent- and source-based air quality standards and policy strategies should be considered, supplementary to standards for total PM mass (e.g., PM₁₀ and PM₂.₅), to effectively protect the population from air pollution mixture. For example, policy measures aiming at controlling anthropogenic sources of coarse particles (e.g., soil/road dust, precursor gases for atmospheric conversion of aged sea salt) should be advisable. / 以往流行病學研究已經建立大氣懸浮顆粒（PM）污染短期暴露和心血管﹑呼吸系統疾病的發病率以及死亡率之間的關聯，但仍然不能確定究竟那種PM化學成分和排放源對暴露人群最有害。初步證據已經顯示了個別PM化學成分和排放源與某些疾病的相關聯，但是，現今研究結果之間依然存在顯著差異。此外，顆粒污染物的化學成分和排放源會隨地理空間不同而變化，因此有必要在不同地域的大氣環境下（如亞洲）進行研究，從而提高我們對PM影響健康的認識。 / 香港的空氣質量常超過世界衛生組織規定的可接受空氣質量標準，空氣污染已經成為一個嚴重的公共衛生問題。香港二十年的空氣污染研究已顯示PM質量濃度會增加死亡率和緊急入院的風險，然而仍然缺乏PM化學成分和排放源對健康影響的研究。本港環境保護署擁有十多年連續測量的可吸入懸浮粒子（PM₁₀）成分數據，因此本論文利用這數據與公共衛生數據來填補這個學術空白。具體的，本論文探索香港2001年至2008年間的PM化學成分與期間每日心血管和呼吸系統緊急入院的關聯。本論文還利用正交矩陣因子分解法（PMF），即大氣顆粒物的源解析技術，進行顆粒源分離，已建立替代單元以分別代表PM₁₀不同排放源的相對貢獻建立一個替代措施量化PM₁₀的成分中不同來源相對的貢獻，最終評估暴露於特定來源的PM₁₀混合成分的健康風險。 / 本文中的時間序列分析研究結果表明緊急入院率與多個PM化學成分在不同的暴露滯後時間上均存在正關聯。本論文的多種污染物時間序列的模型對氣體的共污染性進行了控制，研究發現以下三种顆粒物對某些具體疾病的緊急入院風險有顯著增加︰燃燒有關的顆粒（即︰碳元素，有機物，鉀離子，錳，硝酸根離子，砷，鉛），與海鹽有關的顆粒（即︰鈉離子，氯離子，鎂），以及與土壤/道路粉塵有關的顆粒（即︰鋁，鐵），這種相關性在寒冷的季節更為明顯（即每年的11月至4月）。PMF鑑定了八個PM₁₀的排放源或排放組合，包括︰1）汽車排氣，2）土壤/道路粉塵，3）區域燃燒產物，4）渣油，5）鮮海鹽，6）陳海鹽，7）二次硝酸鹽，和8）二次硫酸鹽。分析發現，除鮮海鹽外，其他PM₁₀的排放源與緊急入院呈正關係。研究顯示與燃燒有關的排放源能增加即時因心血管疾病緊急入院的風險，而主要含有粗顆粒的排放源能增加即時呼吸系統疾病緊急入院的風險，且在作用時間上比燃燒排放源（主要含有細顆粒）的危害更快。 / 本論文所提供的研究成果有助於重新定位未來有關空氣污染與心肺健康的生物學機制毒理學研究方向。研究結果強調監管和降低交通以及其他有關燃燒排放的重要性，利用合理城市環境結構及配置來減少居民暴露交通空氣污染的風險，以及建立區域性的空氣質量管理計劃。此外，本研究還建議除了PM質量濃度（如PM₁₀和PM₂.₅）的空氣質量標準以外，針對PM化學成分和排放源的空氣質量標準也應加以考慮，以有效地保護居民免受空氣污染的危害，例如，應考慮有關粗顆粒（如土壤/道路麈和前驅氣體）的人為來源的政策措施。 / Pun, Chit. / Thesis Ph.D. Chinese University of Hong Kong 2014. / Includes bibliographical references (leaves 108-133). / Abstracts also in Chinese. / Title from PDF title page (viewed on 18, October, 2016). / Pun, Chit. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

A patogênese da fibrose pulmonar idiopática (FPI), forma mais comum de pneumonia intersticial idiopática, não é bem conhecida. Os estudos histopatológicos evidenciam uma extensa lesão do epitélio alveolar com destruição intensa dos pneumócitos tipo e exposição e perda de integridade da membrana basal subjacente, impedindo a reepitelização e rendotelização alveolar, com conseqüente proliferação de fibroblastos e deposição de matriz extracelular. O fator etiológico responsável por essa resposta fibrosante ainda não é conhecido. Em doenças como a síndrome do desconforto respiratório agudo (SDRA) e a lesão pulmonar induzida pela ventilação mecânica, o papel da abertura e fechamento cíclicos das pequenas vias aéreas já está bem estabelecido. Esse estudo tem como objetivo avaliar a presença de colapso alveolar e de pequenas vias aéreas em pacientes com FPI através de tomografia computadorizada (TC) de tórax multislice. As tomografias foram realizadas em 3 diferentes momentos do ciclo respiratório - na capacidade pulmonar total (CPT), na capacidade residual funcional (CRF) e no volume residual (VR) - inicialmente em ar ambiente (O2 a 21%) e as duas últimas etapas, CRF e VR, foram repetidas após 10 minutos de ventilação com O2 a 100%. Admitimos que o surgimento de colapso alveolar após a manobra com O2 a 100% se deve ao fechamento das pequenas vias aéreas seguido de atelectasia de absorção. Foi utilizado o programa Osiris para análise quantitativa das densidades pulmonares e um programa em linguagem LabVIEW 6.0 para quantificação da massa de pulmão não aerado (colapsado) cuja densidade situa-se entre -100 e + 100 UH. A casuística foi composta por 18 pacientes com diagnóstico histológico e/ou clínico de FPI e 12 controles sem doença respiratória conhecida. Os indivíduos do grupo controle foram mais idosos (63 x 70 anos), não havendo diferença quanto à história de tabagismo. A atenuação média do parênquima pulmonar foi maior no grupo fibrose na CPT, CRF 21% e VR 21%. Quando analisamos a massa de pulmão não aerado, o grupo fibrose apresentou valores significativamente maiores do que o grupo controle em todos os volumes respiratórios avaliados em ar ambiente e após O2 a 100%. A avaliação da massa de pulmão não aerado no VR e na CRF após ventilação com O2 a 100%, em comparação com os mesmos volumes pulmonares em ar ambiente, mostrou aumento do colapso tanto em pacientes quanto em controles, não havendo diferença entre os grupos quando se comparou o aumento absoluto da massa de pulmão não aerado após essa manobra. Entretanto, no grupo de pacientes com FPI, houve aumento significativo da massa de pulmão não aerado à medida que se reduziram os volumes pulmonares em ar ambiente, alteração essa não encontrada no grupo controle. Podemos concluir que a ventilação com O2 a 100% causou colapso de vias aéreas tanto nos pacientes quanto no grupo controle. Nos pacientes com FPI, foi evidenciado colapso alveolar durante a ventilação em ar ambiente, colapso esse quase totalmente revertido (88%) após uma manobra de inspiração máxima até a CPT, o que demonstra seu potencial de reversibilidade / The pathogenesis of idiophatic pulmonary fibrosis (IPF), the most common form of idiopathic interstitial pneumonias, is not completely understood. It is related to a type I pneumocyte injury with loss of basement membrane integrity and failure of normal re-epithelialization and re-endothelialization leading to fibroblast proliferation and extra cellular matrix deposition. However, the etiology of this fibroproliferative response is unknown. In ARDS and ventilator-induced lung injury, it has been postulated that the pulmonary injury is caused by the cyclic opening and closing of collapsed airways. Our aim is to measure the collapsed areas of the lung (alveolar and small airways collapse) using a multislice computed tomography (CT) in a group of patients with IPF. They were submitted to a CT scan of the thorax in 5 different situations: at total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV) at 21% O2 as well as at FRC and RV after breathing 100% O2 for 10 minutes. We assumed that the gain in collapsed areas after 100% O2 corresponds to trapped areas with airways closure and absorption atelectasis. We employed the Osiris Software program to the quantitative analysis of CT attenuation of lung tissue and a program written in LabVIEW to measure the mass of nonaerated lung tissue (- 100 to +100 HU). Eighteen IPF patients and twelve controls without respiratory disease were studied. The control group was older than IPF group (70 x 63 years, respectively) and the smoking history was not different between both groups. The mean lung attenuation was higher in IPF patients at TLC, 21% FRC and 21% RV. When we analyzed the mass of nonaerated lung tissue, the IPF group showed significantly higher values in all respiratory maneuvers (TLC, FRC and RV) at 21% O2 and 100% O2. Both groups presented an increase in collapsed areas when exposed to 100% at RV and FRC and this increment was of similar magnitude. However, only IPF patients had an increase in the mass of nonaerated lung tissue when the lung volume was reduced from TLC to FRC and from FRC to RV during air breathing. We concluded that patients and controls had airways collapse after 100% O2 breathing. In contrast, only IPF patients demonstrated alveolar collapse during air breathing which was almost completed reversible after TLC maneuver

Diss. Linköping : Univ., 2003.

Abstract Pulmonary fibrosis, lung cancer and chronic obstructive pulmonary disease (COPD) are severe diseases and common death causes worldwide. Due to the lack of an effective therapy, the investigation of cell biological mechanisms behind these diseases is essential. An activation of stromal cells, including myofibroblasts, is a main feature found in the pathogenesis of lung diseases. Myofibroblasts express alpha-smooth muscle actin (α-SMA), have specific ultrastructure, produce extracellular matrix proteins and possess contractile capacity. Detailed structure and function of myofibroblasts and their roles in healthy and diseased lung are not yet wholly understood. The investigation of the myofibroblasts may further offer novel tools for the acquisition of proper diagnosis, prognosis and medical treatment. The study aimed to characterize the ultrastructural, functional and disease-specific features of stromal cells, particularly myofibroblasts, in interstitial and malignant lung diseases. The functional properties evaluated here were differentiation, invasive and contractile properties. The study material included in vitro stromal cells cultured from bronchoalveolar lavage (BAL) fluids. The appearance and location of myofibroblasts in different lung compartments of non-smokers and the COPD-patients were examined in vivo. The cells were investigated by light and electron microscopy. The α-SMA expression was analysed by gene or protein assays. The study demonstrated that stromal cells could be cultured from diagnostic BAL fluid samples and lung tissues. Cultured cells were a mixture of fibroblasts and myofibroblasts. A small proportion of cells exhibited progenitor-like features. Myofibroblasts revealed differential features in electron microscopy and invasive or contractile assays. When studying tissues from healthy and COPD lungs, myofibroblasts were located both in alveoli and airways. In alveoli myofibroblasts localized in widened alveolar tips which were newly described structures and locations of myofibroblasts in healthy and diseased lung. The amount of myofibroblasts in large airways, but not in peripheral lung, was increased in COPD. We concluded that myofibroblasts have several locations in normal and COPD lung, which suggests a function both in pulmonary regeneration and the pathogenesis of COPD. Smoking altered the phenotype of myofibroblasts regardless of its origin. / Tiivistelmä Keuhkofibroosi, keuhkosyöpä ja keuhkoahtaumatauti (COPD) ovat kansallisesti ja maailmanlaajuisesti yleisiä ja kuolemaan johtavia sairauksia. Taudinmääritys ja hoito ovat vaativia, eikä kaikille potilaille ole parantavaa hoitoa. Keuhkosairauksien kaikkia solubiologisia mekanismeja ei vielä tunneta, mikä on yksi syy lääkekehityksen ongelmiin. Interstitiaaleissa ja pahanlaatuisissa keuhkosairauksissa esiintyy paljon aktiivisia sidekudossoluja, kuten muuntuneita fibroblasteja eli myofibroblasteja. Ne tunnistetaan hienorakenteesta, jota voidaan tutkia elektronimikroskoopilla. Myofibroblastit ilmentävät myös solun sisäistä sileän lihaksen alfa-aktiinia (α-SMA), tuottavat sidekudoksen proteiineja ja kykenevät supistumaan. Myofibroblastien hienorakenteen ja toiminnan selvittäminen voi antaa lisätietoa keuhkosairauksien syntymekanismeista, jolloin diagnostiikkaa, ennustetta sekä hoitoja voidaan arvioida paremmin. Väitöskirjassa selvitettiin myofibroblastien hienorakennetta ja toimintaa eri keuhkosairauksissa. Tutkitut toiminnalliset ominaisuudet olivat erilaistumispotentiaali, invasiivisuus ja supistumiskyky. Sairauksien kliinistä käyttäytymistä ja potilaiden tupakointitottumuksia tarkasteltiin suhteessa solubiologiatason havaintoihin. Tutkimusmateriaali kerättiin taudinmäärityksen yhteydessä interstitiaalisia keuhkosairauksia, keuhkoahtaumatautia tai keuhkosyöpää sairastavilta potilailta. Tulosten mukaan bronkoalveolaarihuuhtelunesteestä (BAL) ja keuhkokudospaloista voidaan soluviljelymenetelmin kasvattaa ja ylläpitää solulinjoja. Viljellyt solut muodostivat sekasolupopulaatiota, joissa esiintyi pääosin fibroblasteja ja vaihteleva osuus myofibroblasteja. Pieni osa soluista ilmensi kantasoluille tyypillisiä piirteitä. Myofibroblastien tyyppipiirteet ja toiminnalliset ominaisuudet vaihtelivat taudeittain. Kudoksessa myofibroblasteja ilmentyi sekä keuhkorakkuloissa että ilmateissä. Keuhkorakkulatasolla myofibroblastit sijoittuivat irrallisten alveoliseinämien laajentuneisiin päihin, joita ei ole aiemmin tutkittu tieteellisessä kirjallisuudessa myofibroblastien yhteydessä. Keuhkoahtaumatauti ja tupakointi vähensivät näiden rakenteiden määrää perifeerisessä keuhkossa, kun taas suurissa ilmateissä keuhkoahtaumatauti lisäsi myofibroblasteja. Päättelimme, että myofibroblastit edistävät keuhkoahtaumataudin syntyä isoissa ilmateissä, mutta saattavat osallistua keuhkojen korjaukseen keuhkorakkuloissa ja pienissä ilmateissä.

O momento ideal para a extubação de crianças graves é ainda difícil de ser avaliado. A razão entre espaço morto e volume corrente (Vd/Vt), como valor preditiva de extubação bem sucedida, já foi testada em adultos e crianças. O objetivo deste trabalho foi avaliar a eficácia do Vd/Vt, como preditivo do sucesso da extubação, em crianças de uma UTI pediátrica geral. Após aplicação dos critérios de inclusão e exclusão, testou-se o Vd/Vt em 86 pacientes extubados num período de 16 meses. Nos estudos estatísticos o índice Vd/Vt médio não discriminou os grupos de falha e sucesso na extubação nas análises uni e multivariada. O valor do índice, com corte em 0,65, foi limitado na sensibilidade e especificidade e mediano na razão de verossimilhança. O estudo sugere que o índice Vd/Vt, pode ser considerado como complementar aos dados de avaliação clínica no momento da extubação. / The ideal moment for extubation of critically ill children is still difficult to determine. The dead-space : tidal volume ratio (Vd/Vt) has been tested as predictor of extubation failure in adults and children. The purpose of this study was to evaluate the efficacy of the Vd/Vt as a predictor of the success of extubation in children admitted to a pediatric intensive care unit. After the inclusion and exclusion criteria, 86 patients were studied during 16 months. The statistical study revealed that the mean Vd/Vt was not able to discriminate between failure and success of extubation in the multivariate analysis. The utility of the Vd/Vt was limited, in terms of sensibility and specificity, using a cutoff of 0,65, but was medially satisfactory in the likelihood ratio. This study suggests that the Vd/Vt can only be considered as complementary to the routine clinical evaluation prior to extubation.