Diss. (sammanfattning) Uppsala : Uppsala universitet, 2009.

This research develops a detailed, anatomically-based model of the human pulmonary circulatory system from the large scale arterial and venous vessels, to the microcirculatory alveolar-capillary unit. Flow is modelled through these networks enabling structure-function simulations to be conducted to increase our understanding of this complex system.Voronoi meshing is applied in a novel technique to represent the three-dimensional structure of the alveoli, and the corresponding capillary plexus intimately wrapped over the alveolar surface. This technique is used to create the alveolar-capillary structure of a single alveolar sac, closely representing the geometry measured in anatomical studies.A Poiseuille type flow solution technique is implemented within the capillary geometry. The solution procedure incorporates calculations of red and white blood cell transit time frequencies. Novel predictions of regional microcirculatory blood cell transit in the anatomically-realistic alveolar-capillary model compare well with experimental measures.An anatomically-based finite element model of the arterial and venous vessels, down to the level of their accompanying respiratory bronchioles, is created using a combination of imaging and computational algorithms, which includes generation of supernumerary vessels. Large arterial and venous vessels and lobar geometries are derived from multi-detector row x-ray computed tomography (MDCT) scans. From these MDCT vessel end points a volume-filling branching algorithm is used to generate the remaining blood vessels that accompany the airways into the MDCT-derived host volume. An empirically-based algorithm generates supernumerary blood vessels - unaccompanied by airways that branch to supply the closest parenchymal tissue. This new approach produces a model of pulmonary vascular geometry that is far more anatomically-realistic than previous models in the literature.A reduced form of the Navier-Stokes equations are solved within the vascular geometries to yield pressure, radius, and velocity distributions. Inclusion of a gravitational term in the governing equations allows application of the model in investigating the relative effects of gravity, structure, and posture on regional perfusion.Gravity is shown to have a lesser influence on blood flow distribution than suggested by earlier experimental studies, and by comparison between different model solutions the magnitude of the gravitational flow gradient is predicted. This study clearly demonstrates the significant role that symmetric vascular branching has in determining the distribution of blood flow. The influence of branching geometry is revealed by solution in symmetric, human, and ovine vascular models.

The mammalian lung is an exquisitely designed organ with two structurally distinct compartments, one that comprises multiple generations of branched tubules to conduct and clean the air (airways) and another that consists of a vast network of thin-walled alveolar structures to allow gas exchange (alveoli). In the embryo these compartments arise from highly dynamic patterning events during branching morphogenesis that define two major domains, a proximal (Sox2+) and a distal (Sox9+), which ultimately form the airways and alveoli, respectively. Although the signaling pathways controlling branching morphogenesis are increasingly understood, the mechanisms that regulate the transition zone (TZ) between the proximal and distal domains are still elusive. The goals of this thesis are to identify markers and molecular regulators of the TZ, to examine the role of Hippo-Yap signaling in the establishment of the TZ and to investigate the evolutionary conservation of this process in the lung of the snake Pantherophis guttata, which lacks a branched airway tree. Using a combination of mouse genetics, single cell RNAseq, computational approaches and immunofluorescence-confocal analyses I show that Yap transcriptional activity and nucleocytoplasmic shuttling are essential for patterning of the lung by being pivotal for initiation of the events that give rise to the TZ, as well as for subsequent lineage differentiation of compartment-specific progenitors. I show that cytoplasmic sequestration of Yap in Sox2+ epithelial progenitors is a crucial mechanism to prevent the deleterious effects of maintaining nuclear Yap once airway progenitors are specified. Moreover, PISCES-inferred protein activity profiling identified Hspa8, Krt19, Btg2, Anxa2, Cldn10 and Icam1 in the TZ. Notably, analyses of Yap loss and gain function in mice revealed Icam1 as a key marker of the TZ and a downstream target of Yap. Lastly, I show that Sox2 and Sox9 are conserved markers of proximal (bronchiolar) and distal (respiratory) cell fate in the respiratory tract. However, in the snake Pantherophis guttata, the early proximal-distal event that specifies the Sox9+ compartment in the mouse appears delayed. I speculate that proximal-distal patterning in murine lung development actually represents a precocious specification event of respiratory identity, as well as that this ultimately enabled the incorporation of a program of branching morphogenesis in the ancestral program of lung development. Considering that in humans the primordial lungs are double Sox2+ Sox9+, this suggests an unsuspected heterogeneity in the early lung developmental events of human, mice, and reptiles. Altogether, the findings revealed by this work open new avenues of research to further understand the molecular mechanisms that drive lung development.

Introdução: O padrão de distribuição da lesão pulmonar na síndrome do desconforto respiratório agudo (SDRA) tem sido alvo de interesse de estudos com tomografia computadorizada. Entretanto, pouca informação é disponível quanto a distribuição e progressão histológica da lesão pulmonar na SDRA. Objetivos: Caracterizar a distribuição e progressão histológica da lesão pulmonar em modelo experimental de SDRA em suínos pela quantificação de parâmetros estruturais, inflamatórios e de remodelamento da matriz extracelular (MEC) e correlacioná-los com variáveis funcionais e de tomografia de impedância elétrica (TIE). Métodos: Vinte e três porcas da raça Landrace foram divididos em três grupos: 1) Sham (n=5): animais submetidos ao preparo e monitorização; 2) Lesão (n=9): animais submetidos ao protocolo de lesão e eutanasiados após 3 horas; 3) Lesão+MV: animais submetidos ao protocolo de lesão e eutanasiados após 40 horas de ventilação mecânica (VM) segundo a \"estratégia ARDSnet\". Os parâmetros histológicos foram mensurados por análise de imagem e incluíam: área alveolar, índice de espessamento septal, densidade neutrofílica, membrana hialina, hemorragia, edema intraalveolar e proporção de fibras colágenas. As medidas de cada parâmetro foram normalizadas pela mediana do grupo Sham. Expressão gênica de proteínas da MEC (colágeno tipo I e tipo III, versican, biglican e decorin) foram quantificados por PCR em tempo real. A ventilação regional foi mensurada por TIE. Foram analisadas regiões anteriores e posteriores do pulmão para cada variável. Resultados: A densidade neutrofílica foi menor no grupo Lesão+VM (p=0,02). A análise da área alveolar no grupo Lesão+VM mostrou que as regiões posteriores apresentaram menor área que as regiões anteriores (p=0,012). Entretanto, o espessamento septal foi maior no grupo Lesão+VM, especialmente nas regiões anteriores, quando comparado ao grupo Lesão (p <= 0,01). Em consonância com esses achados, as regiões anteriores exibiram maior índice de membrana hialina e de edema intraalveolar que as regiões posteriores em ambos os grupos (p < 0,03) e a expressão de colágeno tipo I foi maior na região anterior comparada à região posterior do grupo Lesão+VM (p=0,001). A análise da TIE mostrou que as regiões anteriores receberam maior volume corrente que as regiões posteriores no grupo Lesão (p < 0,001). Nestes animais, a ventilação regional foi correlacionada à densidade neutrofílica (r=0,48; p=0,04), ao índice de hemorragia (r=0,74; p=0,001) e ao índice de membrana hialina (r=0,56; p=0,016). No grupo Lesão+VM, a ventilação regional foi correlacionada à expressão de colágeno tipo I (r=0,494; p=0,05), colágeno tipo III (r=0,656; p=0,006) e versican (r=0,732; p=0,001). Conclusão: Esse estudo mostra a progressão histopatológica e apresentação regional da lesão pulmonar em um modelo de SDRA em suínos. Nesse modelo, o suporte com ventilação mecânica protetora foi eficiente para reduzir a inflamação parenquimatosa, mas não inibiu a progressão da lesão e a sinalização para o processo fibroproliferativo. No curso da lesão, após 40 horas, as regiões anteriores sofreram progressiva redução do lúmen alveolar associada à deposição de membrana hialina e espessamento septal. A lesão progrediu com sinalização difusa para o reparo tecidual, mas com predomínio de expressão de colágeno tipo I nas regiões anteriores. Contudo, a deposição de colágeno parece ser um evento mais tardio / Introduction: The pattern of lesion distribution in acute respiratory distress syndrome (ARDS) has been addressed in computed tomography studies. However, there is little information concerning the progression and distribution of histological lung injury in ARDS. Objectives: To characterize the histological progression and distribution of lung injury in a pig ARDS model by the quantification of structural, inflammatory and extracellular matrix (ECM) remodeling parameters and to correlate them with functional and electrical impedance tomography (EIT) variables . Methods: Twenty-three healthy female Landrace pigs were divided into three groups: 1) Sham (n=5): animals subjected to preparation and monitoring; 2) Injury (n=9): animals subjected to the injury protocol and euthanized after 3 hours. 3) Injury+MV (n=9): animals subjected to the injury protocol and euthanized after 40 hours of ARDSnet mechanical ventilation. Histological parameters measured by image analysis included: alveolar area, septal thickening index, neutrophils density, hyaline membrane, hemorrhage, alveolar edema and collagen fibers content. The parameters values were normalized by Sham group median values. Gene expression of ECM proteins (collagen type I and type III, versican, biglycan and decorin) was quantified by Real Time-PCR. Regional ventilation was measured by EIT. For each variable the anterior and posterior regions of the lung were analyzed. Results: Density neutrophil was lesser in the Injury+MV group (p=0.02). Alveolar area in the posterior regions of the Injury+MV group was lesser than the anterior regions (p=0.012). However, the septal thickening was higher in Injury+MV group, especially in the anterior regions, when compared to the Injury group (p <= 0.01). In consonance with such findings, the hyaline membrane and alveolar edema index in the anterior region was higher than the posterior region in both groups (p < 0.03) and the expression of collagen type I was significantly higher in the anterior region compared to the posterior region in lungs of Injury+MV (p=0.001). The EIT showed that the non-dependent regions (anterior) received more ventilator influx than the dependent regions (p<0.001) in the Injury group. In these animals, the regional ventilation was correlated to neutrophil density (r=0.48; p=0,04), hemorrhage index (r=0.74; p=0.001) and hyaline membrane index (r=0.56; p=0.016). In Injury+MV group, the regional ventilation was correlated to collagen type I (r=0.494; p=0.05), collagen type III (r=0.656; p=0.006) and versican (r=0.732; p=0.001) expressions. Conclusion: This study shows the histopathological progression and the regional presentation of the pulmonary lesion in the ARDS pig model. In our model, the support with protective ventilation was efficient to reduce parenchymal inflammation, but did not inhibit the injury progression and signaling to the fibroproliferative process. Animals ventilated for 40 hours, the anterior regions underwent a progressive reduction in the alveolar lumen associated with alveolar walls thickening and hyaline membrane deposition. The injury progressed with diffuse activation of tissue repair pathway, but with the predominance of collagen type I expression in anterior regions. However, in our study, the deposition of collagen rich matrix is a later event

Introdução: O padrão de distribuição da lesão pulmonar na síndrome do desconforto respiratório agudo (SDRA) tem sido alvo de interesse de estudos com tomografia computadorizada. Entretanto, pouca informação é disponível quanto a distribuição e progressão histológica da lesão pulmonar na SDRA. Objetivos: Caracterizar a distribuição e progressão histológica da lesão pulmonar em modelo experimental de SDRA em suínos pela quantificação de parâmetros estruturais, inflamatórios e de remodelamento da matriz extracelular (MEC) e correlacioná-los com variáveis funcionais e de tomografia de impedância elétrica (TIE). Métodos: Vinte e três porcas da raça Landrace foram divididos em três grupos: 1) Sham (n=5): animais submetidos ao preparo e monitorização; 2) Lesão (n=9): animais submetidos ao protocolo de lesão e eutanasiados após 3 horas; 3) Lesão+MV: animais submetidos ao protocolo de lesão e eutanasiados após 40 horas de ventilação mecânica (VM) segundo a \"estratégia ARDSnet\". Os parâmetros histológicos foram mensurados por análise de imagem e incluíam: área alveolar, índice de espessamento septal, densidade neutrofílica, membrana hialina, hemorragia, edema intraalveolar e proporção de fibras colágenas. As medidas de cada parâmetro foram normalizadas pela mediana do grupo Sham. Expressão gênica de proteínas da MEC (colágeno tipo I e tipo III, versican, biglican e decorin) foram quantificados por PCR em tempo real. A ventilação regional foi mensurada por TIE. Foram analisadas regiões anteriores e posteriores do pulmão para cada variável. Resultados: A densidade neutrofílica foi menor no grupo Lesão+VM (p=0,02). A análise da área alveolar no grupo Lesão+VM mostrou que as regiões posteriores apresentaram menor área que as regiões anteriores (p=0,012). Entretanto, o espessamento septal foi maior no grupo Lesão+VM, especialmente nas regiões anteriores, quando comparado ao grupo Lesão (p <= 0,01). Em consonância com esses achados, as regiões anteriores exibiram maior índice de membrana hialina e de edema intraalveolar que as regiões posteriores em ambos os grupos (p < 0,03) e a expressão de colágeno tipo I foi maior na região anterior comparada à região posterior do grupo Lesão+VM (p=0,001). A análise da TIE mostrou que as regiões anteriores receberam maior volume corrente que as regiões posteriores no grupo Lesão (p < 0,001). Nestes animais, a ventilação regional foi correlacionada à densidade neutrofílica (r=0,48; p=0,04), ao índice de hemorragia (r=0,74; p=0,001) e ao índice de membrana hialina (r=0,56; p=0,016). No grupo Lesão+VM, a ventilação regional foi correlacionada à expressão de colágeno tipo I (r=0,494; p=0,05), colágeno tipo III (r=0,656; p=0,006) e versican (r=0,732; p=0,001). Conclusão: Esse estudo mostra a progressão histopatológica e apresentação regional da lesão pulmonar em um modelo de SDRA em suínos. Nesse modelo, o suporte com ventilação mecânica protetora foi eficiente para reduzir a inflamação parenquimatosa, mas não inibiu a progressão da lesão e a sinalização para o processo fibroproliferativo. No curso da lesão, após 40 horas, as regiões anteriores sofreram progressiva redução do lúmen alveolar associada à deposição de membrana hialina e espessamento septal. A lesão progrediu com sinalização difusa para o reparo tecidual, mas com predomínio de expressão de colágeno tipo I nas regiões anteriores. Contudo, a deposição de colágeno parece ser um evento mais tardio / Introduction: The pattern of lesion distribution in acute respiratory distress syndrome (ARDS) has been addressed in computed tomography studies. However, there is little information concerning the progression and distribution of histological lung injury in ARDS. Objectives: To characterize the histological progression and distribution of lung injury in a pig ARDS model by the quantification of structural, inflammatory and extracellular matrix (ECM) remodeling parameters and to correlate them with functional and electrical impedance tomography (EIT) variables . Methods: Twenty-three healthy female Landrace pigs were divided into three groups: 1) Sham (n=5): animals subjected to preparation and monitoring; 2) Injury (n=9): animals subjected to the injury protocol and euthanized after 3 hours. 3) Injury+MV (n=9): animals subjected to the injury protocol and euthanized after 40 hours of ARDSnet mechanical ventilation. Histological parameters measured by image analysis included: alveolar area, septal thickening index, neutrophils density, hyaline membrane, hemorrhage, alveolar edema and collagen fibers content. The parameters values were normalized by Sham group median values. Gene expression of ECM proteins (collagen type I and type III, versican, biglycan and decorin) was quantified by Real Time-PCR. Regional ventilation was measured by EIT. For each variable the anterior and posterior regions of the lung were analyzed. Results: Density neutrophil was lesser in the Injury+MV group (p=0.02). Alveolar area in the posterior regions of the Injury+MV group was lesser than the anterior regions (p=0.012). However, the septal thickening was higher in Injury+MV group, especially in the anterior regions, when compared to the Injury group (p <= 0.01). In consonance with such findings, the hyaline membrane and alveolar edema index in the anterior region was higher than the posterior region in both groups (p < 0.03) and the expression of collagen type I was significantly higher in the anterior region compared to the posterior region in lungs of Injury+MV (p=0.001). The EIT showed that the non-dependent regions (anterior) received more ventilator influx than the dependent regions (p<0.001) in the Injury group. In these animals, the regional ventilation was correlated to neutrophil density (r=0.48; p=0,04), hemorrhage index (r=0.74; p=0.001) and hyaline membrane index (r=0.56; p=0.016). In Injury+MV group, the regional ventilation was correlated to collagen type I (r=0.494; p=0.05), collagen type III (r=0.656; p=0.006) and versican (r=0.732; p=0.001) expressions. Conclusion: This study shows the histopathological progression and the regional presentation of the pulmonary lesion in the ARDS pig model. In our model, the support with protective ventilation was efficient to reduce parenchymal inflammation, but did not inhibit the injury progression and signaling to the fibroproliferative process. Animals ventilated for 40 hours, the anterior regions underwent a progressive reduction in the alveolar lumen associated with alveolar walls thickening and hyaline membrane deposition. The injury progressed with diffuse activation of tissue repair pathway, but with the predominance of collagen type I expression in anterior regions. However, in our study, the deposition of collagen rich matrix is a later event

Cette thèse a pour cadre la modélisation du dépôt de particules dans le poumon humain afin d'optimiser l'administration de médicaments par voie inhalée. La région alvéolaire du poumon jouant un rôle physiologique et fonctionnel crucial, l'objectif de ce travail est de mettre en place un modèle de dépôt au sein de la région acinaire qui soit intégrable à un modèle intégrant le poumon complet. Les deux premiers chapitres rappellent les caractéristiques anatomiques et fonctionnelles du poumon et en particulier de la région alvéolaire ainsi que les principes physiques mis en jeu lors de l'écoulement de l'air et du transport de particules dans l'arbre pulmonaire. Puis un modèle numérique d'écoulement dans une géométrie alvéolaire simplifiée est présenté. Le transport d'un bolus d'aérosol y est étudié par une approche eulérienne, au cours de plusieurs cycles respiratoires ; l'impact des irréversibilités de l'écoulement sur la dispersion du bolus est ensuite quantifié. Le dernier chapitre présente l'intégration des résultats précédents au sein d'un modèle analytique de dépôt de particules dans le poumon. Les résultats générés par ce modèle sont ensuite comparés aux données expérimentales issues de la littérature ou obtenues lors d'une étude clinique en cours, spécifiquement orientée sur la mesure du dépôt de particules dans les voies aériennes. Les résultats du modèle montrent une augmentation du dépôt de particules dans la région acinaire, présentant un bon accord avec les données expérimentales. Ce modèle pourrait aider à la conception de thérapies ciblant spécifiquement la région alvéolaire du poumon / The context of this thesis is the modelling of particle deposition in the human lung in order to optimise the administration of inhaled drugs. As the alveolar region plays a crucial role both physiologically and functionally, especially for systemic delivery, the objective of this work is to set-up a particle deposition model specific to the acinar region which could be integrated in whole lung deposition model. The first two chapters concentrate on the anatomical and functional aspects of the lung and on the physical principles involved in the flow and particle transport mechanisms in the lung. Then a computational fluid dynamics model was setup in a simplified alveolar geometry. Aerosol bolus transport was studied through an Eulerian approach, for one or several breathing cycles. The impact of flow irreversibilities on bolus dispersion was quantified. The last chapter deals with the integration of the previous results in an analytical model of particle deposition in the whole lung. The results generated by this model are then compared to experimental data from the literature or obtained from an ongoing clinical trial. The results of the new theoretical model show an increase of particle deposition in the acinar region which improves correlation of theory with experimental data. This model could favourably help designing therapies targeting the alveolar region of the lung

A hemorragia alveolar é uma síndrome que pode ocorrer como manifestação de uma série de doenças, cada uma com eventos fisiopatológicos diferentes resultando em sangramento pulmonar. A análise histológica detalhada destes pacientes pode auxiliar no entendimento desta síndrome. Neste estudo nós fizemos a revisão e descrição dos achados das lâminas de tecido pulmonar e do prontuário médico de 48 pacientes falecidos por hemorragia alveolar nos anos de 1999 a 2004. A maioria apresentou hemorragia de característica difusa (87,5%), predominantemente alveolar (79,2%), sem sinais de recorrência (79,2%) e com presença de fibrina (81,3%). As outras características avaliadas foram: vasculite (8,3%), trombose intravascular (27,1%),esclerose arterial (31,3%), capilarite (41,7%), acometimento intersticial (35,4%), acometimento venoso (41,7%), presença de sinais de infecção (50%), membrana hialina (25%). Com os registros médicos, classificamos os pacientes nas seguintes síndromes clínicas: congestão pulmonar (29,17%), coagulopatia (25%), sepse (27,08%) e inflamação (18,75%). Após as análises clínica e histológica, fizemos a correlação entre estes dados e encontramos que os pacientes com diagnóstico de congestão apresentaram menor presença de fibrina e de acometimento intersticial e maior presença de sangramento focal. O sangramento por coagulopatia se caracterizou por menor presença de fibrina e ausência de sinais de sangramento recorrente. Os pacientes com infecção clínica, histologicamente apresentaram fibrina e sinais de infecção no tecido pulmonar, já os pacientes com diagnóstico de inflamação se caracterizaram pela presença de fibrina, esclerose arterial e sangramento focal. Concluindo, nosso estudo sugere que alguns padrões histológicos são mais comuns em determinadas síndromes clínicas, e podem ser úteis no diagnóstico causal da hemorragia alveolar / Alveolar haemorrhage is a syndrome presented by many diseases each one with its particular physiopathologic mechanism resulting in pulmonary bleeding. The detailed histological analysis of these patients can help understanding this syndrome. In this study we reviewed and described histological findings of lung slides and medical records from patients whose cause of death was alveolar haemorrhage between 1999 and 2004. Most patients presented diffuse (87,5%), mainly alveolar (79,2%) rather than interstitial and recent bleeding with no signs of recurrence (79,2%). We also observed the presence of: fibrin (81,3%), vasculitis (8,3%), intravascular thrombosis (27,1%), arterial sclerosis (31,3%), capillarity (41,7%), interstitial involvement (35,4%), venous involvement (41,7%), signs of infection on lung tissue (50%) and hyaline membrane (25%). Clinically we classified the patients as having one of the following syndromes: pulmonary oedema due to congestive heart failure (CHF- 29,17%), coagulation disorders (25%), sepsis (27,08%) and systemic inflammation (18,75%). After correlating clinical and histological data we found CHF to have lower presence of fibrin and interstitial involvement and a greater presence of focal bleeding. Coagulation disorders were characterized by no signs of recurrent bleeding and a lower presence of fibrin than infection and inflammation. Patients with clinical diagnosis of systemic inflammation had a greater presence of fibrin and arterial sclerosis than other clinical syndrome and patients with clinical diagnosis of sepsis showed presence of signs of infection in lung tissue no matter the clinical site of infection. In conclusion, our study suggests that some histological patterns happens more commonly in determined clinical syndromes and can help diagnosing the cause of bleeding .

A hemorragia alveolar é uma síndrome que pode ocorrer como manifestação de uma série de doenças, cada uma com eventos fisiopatológicos diferentes resultando em sangramento pulmonar. A análise histológica detalhada destes pacientes pode auxiliar no entendimento desta síndrome. Neste estudo nós fizemos a revisão e descrição dos achados das lâminas de tecido pulmonar e do prontuário médico de 48 pacientes falecidos por hemorragia alveolar nos anos de 1999 a 2004. A maioria apresentou hemorragia de característica difusa (87,5%), predominantemente alveolar (79,2%), sem sinais de recorrência (79,2%) e com presença de fibrina (81,3%). As outras características avaliadas foram: vasculite (8,3%), trombose intravascular (27,1%),esclerose arterial (31,3%), capilarite (41,7%), acometimento intersticial (35,4%), acometimento venoso (41,7%), presença de sinais de infecção (50%), membrana hialina (25%). Com os registros médicos, classificamos os pacientes nas seguintes síndromes clínicas: congestão pulmonar (29,17%), coagulopatia (25%), sepse (27,08%) e inflamação (18,75%). Após as análises clínica e histológica, fizemos a correlação entre estes dados e encontramos que os pacientes com diagnóstico de congestão apresentaram menor presença de fibrina e de acometimento intersticial e maior presença de sangramento focal. O sangramento por coagulopatia se caracterizou por menor presença de fibrina e ausência de sinais de sangramento recorrente. Os pacientes com infecção clínica, histologicamente apresentaram fibrina e sinais de infecção no tecido pulmonar, já os pacientes com diagnóstico de inflamação se caracterizaram pela presença de fibrina, esclerose arterial e sangramento focal. Concluindo, nosso estudo sugere que alguns padrões histológicos são mais comuns em determinadas síndromes clínicas, e podem ser úteis no diagnóstico causal da hemorragia alveolar / Alveolar haemorrhage is a syndrome presented by many diseases each one with its particular physiopathologic mechanism resulting in pulmonary bleeding. The detailed histological analysis of these patients can help understanding this syndrome. In this study we reviewed and described histological findings of lung slides and medical records from patients whose cause of death was alveolar haemorrhage between 1999 and 2004. Most patients presented diffuse (87,5%), mainly alveolar (79,2%) rather than interstitial and recent bleeding with no signs of recurrence (79,2%). We also observed the presence of: fibrin (81,3%), vasculitis (8,3%), intravascular thrombosis (27,1%), arterial sclerosis (31,3%), capillarity (41,7%), interstitial involvement (35,4%), venous involvement (41,7%), signs of infection on lung tissue (50%) and hyaline membrane (25%). Clinically we classified the patients as having one of the following syndromes: pulmonary oedema due to congestive heart failure (CHF- 29,17%), coagulation disorders (25%), sepsis (27,08%) and systemic inflammation (18,75%). After correlating clinical and histological data we found CHF to have lower presence of fibrin and interstitial involvement and a greater presence of focal bleeding. Coagulation disorders were characterized by no signs of recurrent bleeding and a lower presence of fibrin than infection and inflammation. Patients with clinical diagnosis of systemic inflammation had a greater presence of fibrin and arterial sclerosis than other clinical syndrome and patients with clinical diagnosis of sepsis showed presence of signs of infection in lung tissue no matter the clinical site of infection. In conclusion, our study suggests that some histological patterns happens more commonly in determined clinical syndromes and can help diagnosing the cause of bleeding .

The context of this thesis is the modelling of particle deposition in the human lung in order to optimise the administration of inhaled drugs. As the alveolar region plays a crucial role both physiologically and functionally, especially for systemic delivery, the objective of this work is to set-up a particle deposition model specific to the acinar region which could be integrated in whole lung deposition model. The first two chapters concentrate on the anatomical and functional aspects of the lung and on the physical principles involved in the flow and particle transport mechanisms in the lung. Then a computational fluid dynamics model was setup in a simplified alveolar geometry. Aerosol bolus transport was studied through an Eulerian approach, for one or several breathing cycles. The impact of flow irreversibilities on bolus dispersion was quantified. The last chapter deals with the integration of the previous results in an analytical model of particle deposition in the whole lung. The results generated by this model are then compared to experimental data from the literature or obtained from an ongoing clinical trial. The results of the new theoretical model show an increase of particle deposition in the acinar region which improves correlation of theory with experimental data. This model could favourably help designing therapies targeting the alveolar region of the lung

<p>Akutni respiratorni distres sindrom (ARDS) predstavlja klinički sindrom koji se manifestuje te&scaron;kom respiratornom insuficijencijom sa razvojem akutnog edema pluća u odsustvu znakova popu&scaron;tanja leve polovine srca. S obzirom da ovaj sindrom ima heterogenu etiologiju, progresivan tok i visoku stopu mortaliteta, pravovremena i tačna dijagnoza esencijalna je u primeni efektivne i rane terapije, a samim tim i u pobolj&scaron;anju prognoze bolesti. Cilj ove doktorske disertacije bio je da se ispita povezanost kliničke i patohistolo&scaron;ke dijagnoze ovog sindroma, kao i da se analiziraju i uporede vrednosti kliničkih parametara neophodnih za postavljanje dijagnoze ARDS-a sa patohistolo&scaron;kim parametrima o&scaron;tećenja plućnog tkiva. Studija je obuhvatila 67 pacijenata Instituta za plućne bolesti Vojvodine koji su umrli pod kliničkom slikom ARDS-a i/ili kod kojih je na obdukciji patohistolo&scaron;ki dokazan ARDS. Za postavljanje kliničke dijagnoze ARDS-a kori&scaron;ćeni su kriterijumi The American-European Consensus Conference iz 1994. Nakon semikvantitativne analize patohistolo&scaron;kih parametara difuznog alveolarnog o&scaron;tećenja određivan je histolo&scaron;ki stadijum ARDS-a i svi pacijenti podeljeni su u dve grupe: I grupa - pacijenti u eksudativnoj fazi i II grupa - pacijenti u proliferativnoj fazi difuznog alveolarnog o&scaron;tećenja. Formirane grupe pacijenata upoređivane su u odnosu na vrednosti kliničkih parametara 12h pre smrtnog ishoda. U cilju procene prisustva komorbiditeta analizirani su indeks telesne mase (engl. body mass index- BMI) i podaci o prethodno dijagnostikovanoj arterijskoj hipertenziji. Kod svih pacijenata uključenih u studiju upoređivane su kliničke dijagnoze sa obdukcionim nalazom. Za klasifikaciju autopsijskih dijagnoza kori&scaron;ćena je Goldman-ova klasifikacija. Na osnovu provedenog istraživanja, do&scaron;lo se do zaključka da slaganje klinički dijagnostikovanih i patohistolo&scaron;ki potvrđenih slučajeva ARDS-a iznosi 68%. Senzitivnost kliničke dijagnoze ARDS-a iznosi 82%, a pozitivna prediktivna vrednost 80%. Pacijenti sa nalazom eksudativne faze DAD-a u plućnom tkivu su u najvećem procentu imali klinički težak ARDS, dok su se pacijenti sa nalazom proliferativne faze sindroma če&scaron;će manifestovali pod kliničkom slikom srednje te&scaron;kog ARDS-a, odnosno utvrđeno je da postoji statistička povezanost između nižih vrednosti PaO2/FiO2 i teže faze ARDSa. Patohistolo&scaron;kom analizom promena u plućnom tkivu nađeno je da najvažnija obeležja eksudativne faze ARDS-a predstavljaju: hijaline membrane, edem i krvarenje, dok su se kao najvažnija obeležja proliferativne faze ARDS-a izdvojili: proliferacija pneumocita tipa II, intersticijalna i mutilantna fibroza i organizirajuća pneumonija. Kod pacijenata sa kliničkom dijagnozom ARDS-a kod kojih ARDS nije i patohistolo&scaron;ki dokazan, najče&scaron;ći nalaz na plućima bila je fibrinozno-purulentna bronhopneumonija. Analizom etiolo&scaron;kih faktora koji doprinose razvoju ovog sindroma otkriveno je da je ARDS najče&scaron;će nastao kao posledica delovanja direktnih/pulmonalnih činilaca: pneumonije i virusa gripa H1N1. Najzastupljeniji komorbiditeti prisutni kod pacijenata sa ARDS-om bili su sistemska hipertenzija i gojaznost. Najzad, kod svih pacijenata uključenih u istraživanje upoređivane su kliničke dijagnoze sa obdukcionim nalazom i na osnovu Goldman-ove klasifikacije kliničke dijagnoze i obdukcioni nalaz slažu se u 72% slučajeva. Rezultati ove studije mogli bi se upotrebiti u daljim istraživanjima kako bi omogućili bolji dijagnostički pristup ovom problemu, a samim tim i bolji terapijski pristup i smanjivanje stope mortaliteta.</p> / <p>Acute respiratory distress syndrome (ARDS) is a clinical syndrome characterized by severe respiratory failure with development of acute pulmonary edema in the absence of left heart failure signs. Since this syndrome has a heterogeneous etiology, progressive course and high mortality, timely and accurate diagnosis is essential in the implementation of effective and early treatment, and therefore in improving the prognosis of the disease. The aim of this PhD thesis was to examine the association between clinical and pathohistological diagnosis of this syndrome, as well as to analyze and compare the values of clinical parameters necessary for the diagnosis of ARDS with pathohistological parameters of diffuse alveolar damage. The study included 67 patients of the Institute for Lung Diseases who died under clinical picture of ARDS and / or in which, at the autopsy, pathohistological diagnosis of ARDS was set. To set up a clinical diagnosis of ARDS the criteria of the American-European Consensus Conference in 1994 were used. After a semi-quantitative analysis of histopathological parameters of diffuse alveolar damage, all patients were divided into two groups: Group I - patients in the exudative stage and Group II - patients in the proliferative phase of diffuse alveolar damage. Formed groups of patients were compared with respect to clinical parameters values 12 h before death. In order to assess the presence of comorbidities body mass index (BMI) and data on previously diagnosed arterial hypertension were analyzed. In all patients included in the study the clinical diagnosis were compared with autopsy findings according to Goldman&#39;s classification. According to this study, agreement of clinically diagnosed and histologically confirmed cases of ARDS is 68%. The sensitivity of clinical diagnosis of ARDS is 82%, and positive predictive value is 80%. Patients with exudative phase of DAD most frequently had a severe form of ARDS, whereas patients with proliferative phase often manifested with moderate form of ARDS, ie it was found that there is a statistical association between lower values PaO2 / FiO2 and more severe phase of ARDS. Pathological analysis of changes in lung tissue revealed that the most important characteristics of exudative phase of ARDS are: hyaline membrane, edema and bleeding, while the most important features of the proliferative phase of ARDS are: the proliferation of type II pneumocytes, interstitial fibrosis and mutilating and organizing pneumonia. In patients with a clinical diagnosis of ARDS in which ARDS was not pathohistologically proven, the most common finding in the lungs was fibrinous-purulent bronchopneumonia. The analysis of etiological factors that contribute to the development of this syndrome discovered that ARDS usually develop as a result of pulmonary factors: pneumonia and influenza virus H1N1. The most common comorbidities present in patients with ARDS were systemic hypertension and obesity. Finally, in all patients included in the study clinical diagnosis and autopsy findings were compared and based on Goldman&#39;s classification clinical diagnosis and autopsy findings are in agreement in 72% of cases. The results of this study could be used in further research to enable better diagnostic approach to this problem, and therefore a better therapeutic approach and reducing mortality rates.</p>