No description available.

This thesis reports on our initial work constructing a human lung query atlas which provides clinically relevant population statistics for normal and abnormal individuals. The atlas incorporates front-end interfaces with back-end database. The interfaces were developed using Microsoft Access 2007 and the database was implemented using MySQL. ODBC was used to import database into Access and provide connection for database and interfaces. VBA is used to write SQL queries and realized the interaction with interfaces. SQL queries is written to extract the data which researchers may interest in. The atlas provides measurements of the human airway tree and lung volumes from a population of individuals and also provides a population statistics based on age, race, ethnicity, gender and other information. It also provides functionality for comparing airway measurements between populations, individuals to a population, and individuals to individuals. Statistical significance, such as p-value, is provided to analyze two individuals or populations.

Le travail présenté ici porte sur l’étude de la production et du transport du monoxyde d’azote (NO) dans le poumon humain. Le NO est une molécule dont l’implication dans des processus physiologiques n’a été mis en évidence qu’en 1987. Depuis, il a été démontré que le NO joue de nombreux rôles dans le corps humain. Le NO est un gaz labile (instable) dans les conditions physiologiques, il diffuse très facilement au travers des parois et il a une grande affinité pour l’hémoglobine. La production du NO est liée à 3 isoformes différentes de la protéine appelées synthases du NO ou NO synthases. En 1991, Gustafsson et al. ont découvert du NO endogène (produit par les poumons) dans l’air exhalé chez l’homme et le cochon d’Inde. Depuis près de 15 ans, de plus en plus de groupes de recherche travaillent sur le NO pulmonaire sans s’accorder sur ses rôles exactes. Il est cependant établit que, dans les pathologies comme l’asthme, la production accrue de NO est liée aux processus inflammatoires. Le NO peut être produit par la surface épithéliale (au niveau des conduits pulmonaires) ou alvéolaire, mais les sites exactes de production sont encore débattus. De part l’impossibilité de mesures directes au-delà des premières générations de l’arbre bronchique, les modèles mathématiques sont indispensables pour interpréter les résultats de mesures de concentrations exhalées et étudier la production et le transport du NO dans le poumon. Récemment, un modèle a été proposé par notre groupe, tenant compte de la convection, de la diffusion moléculaire et de la production du NO dans le poumon. Le but de ce travail est d’utiliser et d’adapter ce modèle pour reproduire des résultats expérimentaux soit existants, soit originaux. Dans ce travail, nous montrons que l’augmentation de concentration alvéolaire chez des sujets asthmatiques bien contrôlés est liée à une augmentation de production dans les conduits et non dans les alvéoles. Nous montrons également que, sur base de résultats expérimentaux, la production bronchique dans le poumon des sujets sains doit être très hétérogène pour reproduire des résultats expérimentaux apparemment irréconciliables. Nous montrons enfin que la localisation des conduits pulmonaires subissant une constriction influence la chute de NO exhalé mesurée après cette constriction. Nous avons également participé à 2 expériences liées à la gravité qui constitueront le matériel susceptible de faire évoluer le modèle.

The maintenance of the airway/respiratory epithelium during adult homeostasis and repair and its construction during embryonic development require tightly regulated cell fate decisions. This regulation takes the form of complex transcription factor and signalling cascades, much of which are unknown, particularly in human lung development. Multiciliogenesis describes the process of specification/differentiation of airway epithelial progenitors/stem cells into mature multiciliated cells (MCCs). Here, I have identified 2 novel transcription factors, Fank1 and Jazf1 which form part of the transcription factor cascade regulating multiciliogenesis in adult and embryonic mouse tracheas. Mouse tracheal epithelium is representative of epithelium lining the entire human airway and it is possible that we will also be able to extrapolate these findings to the human airway. It is not until we fully understand the regulation of multiciliogenesis that it will be possible to look at ways of pushing basal cells towards a MCC fate for purposes of cell replacement therapy, for example in patients with mucociliary disease. As well as exploring cell fate decisions in the mouse upper airway epithelium using embryonic tracheal explants and mouse tracheal epithelial cell (MTEC) cultures, I have also explored the regulation of cell fate decisions in distal human lung epithelium at the pseudoglandular stage of development. At this stage SOX9+ distal tip cells are self-renewing and multipotent and give rise to SOX2+ stalk descendents, which differentiate into airway epithelium. The regulation of SOX9+ lung tip cell multipotency and migration of SOX2+ stalk descendents during human lung development is poorly understood. I have compared human tip (SOX9+) versus stalk (SOX2+) transcriptomes using gene ontology (GO), which has highlighted some key signalling pathways enriched in tip cells which could be important in maintaining distal tip cell multipotency. These pathways have been utilised in optimising conditions for propagating self-renewing tip-derived organoids. These organoids have the potential to be differentiated into bronchiolar and alveolar fates and as such are an invaluable research tool for studying human lung epithelial development, whilst minimising the use of human embryos and its associated ethical implications. I have also performed human tip versus mouse tip transcriptome GO analysis which highlights that although there are many similarities, there are also differences between human and mouse lung epithelium development, emphasising the need for research on human tissue.

The processes of lung ventilation and perfusion, diffusion, and gas transport make up the system of breathing and tissue oxygenation. Here, we present several mathematical formulations of the essential processes that contribute to breathing. These models aid in our understanding and analysis of this complex system and can be used to form treatments for patients on ventilators. With the right analysis and treatment options, patients can be helped and money can be saved. We conclude with the formulation of a mathematical model for the exchange of gasses in the body based on basic reaction kinetics.

This thesis investigates variability in airway caliber and the distribution of ventilation within the human lung as thought to occur in asthma. Currently, the understanding of how an integrated network of airways can lead to temporal and spatial variation as found in the human lung is unclear. Throughout this thesis, a multibranch airway tree model was used in a forward modeling approach. In a variability study, the mean airway resistance (RL) was observed to be proportional to the standard deviation in airway resistance (SDRL) as reported in the literature under several conditions of airway diameter indicating the strong robustness of this behavior. The model predicted previously reported RL distributions and the reported proportionality of SDRL and RL, but only when we included coherency between airways. In a second study, patient specific ventilation was investigated using an image functional approach by closing specific airways (creating defects) identified by hyperpolarized 3He MRI from asthmatic subjects. Impedance predictions from the imposed heterogeneous ventilation were then calculated and correlated to 3He MRI ventilation defect percent (VDP), plethysmography, and spirometry data. These predictions suggest the forced oscillation technique (FOT) to be a superior metric toward the evaluation of the VDP. In a third study, we investigated how asymmetric branching could play a role in ventilation defect emergence and persistence. At high muscle activation levels simulating an asthmatic episode, airway trees with greater asymmetry reached steady state sooner, with defects that were more persistent in location, had lower RL values (~50%), and greater EL values (~25%) after bronchoconstriction. These results suggest the initial formation of ventilation defects was dependent on airway instability; however, the location and persistence of ventilation defects may be due to geometric airway structure. By modeling the contribution of ventilation defects to lung impedance, we were able to show that defects can play a role in governing the relationship between RL and its variation, and the effect of defects through VDP could be better assessed using FOT. Moreover, lung structure contributed to the emergence and persistence of ventilation defects, meaning that defects could be potentially ameliorated through structural intervention.

No description available.

No / The use of nanoparticles have provided numerous of advantages in medicine due to their unique physiochemical characteristics such as size, charge, shape and surface reactivity [1-4]. Understanding the interaction between engineered nanomaterials and living matter has attracted increasing attention in recent years. Toxicity of nanoparticles was studied in different cell types and cell lines. Nano-SiO2 has good stability, easy dispensability, and melting degeneration, and is widely used in rubber, paints, biomedical and biotechnology fields [5]. In this study, the LDH assay and the MTT assay were applied to evaluate the cytotoxicity of in vitro Silicon dioxide nanoparticles (SiO2-NP, 20nm) on cultured cell lines. Human lung adenocarcinoma epithelial cell line (A549) were used as a lung related cell line and human keratinocyte cell line (HaCaT) as a skin related cell line representing different uptake routes. The percentage cytotoxicity of the silicon dioxide nanoparticles was measured once cultured in a 24 hour incubation period. The concentration of the SiO2 nanoparticles chosen was 10, 50, 100 and 200µg/ml. To measure the cytotoxicity of nanoparticle on cultured cell lines, we used 104*cells/100 µl of cell culture media being placed in a 96 well rounded bottom plate with the LDH assay. The extracellular lactate dehydrogenase release was measured by using a colorimetric CytoTox 96 non-radioactive assay kit and the absorbance was recorded at 492nm. The MTT assay was used to evaluate mitochondrial activity which includes cell growth and cell death. This has been performed by inserting a premixed optimized dye solution in the culture wells. The Absorbance was recorded at 570 nm, from the recorded absorbance is directly proportional to the number of live cells. In order to maintain the cell lines, they were placed in a plastic T-75cm² tissue culture flasks grown in Dulbecco's Modified Eagle's Medium. Studies were performed in the absence of serum. Cytotoxicity was found in both cells the A549 and HaCaT cells and cytotoxicity increased as concentration of the silicon dioxide increased. The percentage cytotoxicity calculated was higher in HaCaT cells compared to the A549 cells. A cell count assay was plated in order to display the cell number of both the HaCaT and A549 cells. The cell count reaffirmed that cytotoxicity did occur as the cell count decreased as the concentration of the silicon dioxide increased compared to the control. These results show that silicon dioxide nanoparticles acted differently in two different cell types and that the metabolic rate of a cell can be used to determine the nanoparticles affect. Further understanding of the mechanism involving the ROS generation could provide more information on how silicon dioxide nanoparticles increase cytotoxicity. / Physiology 2015 conference abstract

Considerando que várias mutações gênicas estão envolvidas no estabelecimento dos tumores, surge a idéia de que o alcance da melhor eficiência no tratamento do câncer é dado pela entrega de múltiplos genes. Este trabalho apresenta a construção, produção e caracterização funcional in vitro e in vivo do vetor adenoviral bicistrônico Adp16IRESp53 e dos monocistrônicos Adp16 e Adp53 em modelo de câncer de pulmão. Nossos resultados indicam uma forte indução de morte celular nas células H358 transduzidas com Adp16IRESp53 em comparação com vetores monocistrônicos Adp16, Adp53 ou o reporter AdeGFP e/ou AdLacZ. Nos ensaios in vivo, utilizando modelo xenografico onde as células H358 foram implantadas no subcutâneo de camundongos atímicos Balb/C nude, pudemos confirmar também in vivo a significativa inibição do crescimentos dos tumores tratados com Adp16IRESp53. Em conclusão, a remediação simultânea de p16INK4a e p53, mediada pelo arranjo bicistrônico, pode ser considerada como uma estratégia promissora para terapia gênica do câncer de pulmão. / This work presents the construction, production and functional evaluation in vitro and in vivo of the bicistronic adenoviral vector Ap16IRESp53 as well as the monocistronic vectors Adp16 and Adp53 in a lung cancer model. Considering that several mutation events are involved in tumorigenesis, comes the idea that a greater efficiency in cancer treatment would be reached with delivery of multiples genes. Our data demonstrate a strong cell death effect in H358 cells transduced with Adp16IRESp53 when compared with Adp16, Adp53 or the reporter AdeGFP and/or AdLacZ. For the in vivo studies, we have used H358 cells implanted subcutaneously in athymic Balb/c nude mice. Our data show significant suppression of tumors treated with the therapeutic adenoviral vector, Adp16IRESp53. In conclusion, the simultaneous replacement of p16INK4a and p53, mediated by the bicistronic vector, may prove to be a promising strategy for gene therapy of lung cancer.

Considerando que várias mutações gênicas estão envolvidas no estabelecimento dos tumores, surge a idéia de que o alcance da melhor eficiência no tratamento do câncer é dado pela entrega de múltiplos genes. Este trabalho apresenta a construção, produção e caracterização funcional in vitro e in vivo do vetor adenoviral bicistrônico Adp16IRESp53 e dos monocistrônicos Adp16 e Adp53 em modelo de câncer de pulmão. Nossos resultados indicam uma forte indução de morte celular nas células H358 transduzidas com Adp16IRESp53 em comparação com vetores monocistrônicos Adp16, Adp53 ou o reporter AdeGFP e/ou AdLacZ. Nos ensaios in vivo, utilizando modelo xenografico onde as células H358 foram implantadas no subcutâneo de camundongos atímicos Balb/C nude, pudemos confirmar também in vivo a significativa inibição do crescimentos dos tumores tratados com Adp16IRESp53. Em conclusão, a remediação simultânea de p16INK4a e p53, mediada pelo arranjo bicistrônico, pode ser considerada como uma estratégia promissora para terapia gênica do câncer de pulmão. / This work presents the construction, production and functional evaluation in vitro and in vivo of the bicistronic adenoviral vector Ap16IRESp53 as well as the monocistronic vectors Adp16 and Adp53 in a lung cancer model. Considering that several mutation events are involved in tumorigenesis, comes the idea that a greater efficiency in cancer treatment would be reached with delivery of multiples genes. Our data demonstrate a strong cell death effect in H358 cells transduced with Adp16IRESp53 when compared with Adp16, Adp53 or the reporter AdeGFP and/or AdLacZ. For the in vivo studies, we have used H358 cells implanted subcutaneously in athymic Balb/c nude mice. Our data show significant suppression of tumors treated with the therapeutic adenoviral vector, Adp16IRESp53. In conclusion, the simultaneous replacement of p16INK4a and p53, mediated by the bicistronic vector, may prove to be a promising strategy for gene therapy of lung cancer.