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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Avaliação da técnica de cintilografia da perfusão pulmonar em cães / Evaluation of pulmonary perfusion scintigraphy technique in dogs

Rodrigues, Gabriela Silva 27 February 2004 (has links)
A avaliação da técnica de cintilografia da perfusão pulmonar foi realizada em 10 cães machos, da raça Rottweiler, radiograficamente normais e soronegativos para dirofilariose, utilizando-se o macroagregado de albumina sérica humana marcado com tecnécio-99m ([99mTc](MAA)) como radiofármaco. Cada animal sedado foi submetido a três diferentes tratamentos, com administração de 50.000, 100.000 e 300.000 partículas de MAA. As imagens obtidas com as doses variadas do radiofármaco, foram comparadas de forma qualitativa e quantitativa, incluindo nesta última a avaliação do índice de perfusão pulmonar e homogeneidade das imagens. Não foram observadas diferenças significativas entre as imagens durante a avaliação visual e cálculo da quantificação relativa da perfusão pulmonar. Porém, o cálculo da uniformidade integral demonstrou diferença significativa na homogeneidade da imagem pulmonar entre as diferentes doses de MAA. Pode-se concluir que existe um aumento na homogeneidade da imagem diretamente relacionado ao número de partículas de magroagregado de albumina injetado, ainda que tal diferença não tenha sido percebida pela análise qualitativa. / The evaluation of pulmonary perfusion scintigraphy technique was accomplished in 10 Rottweiler male dogs, with normal thoracic radiographs and negative for Dirofilaria immitis, using macroaggregated human serum albumin tagged with technetium-99m ([99mTc](MAA)) as radiopharmaceutical. Each sedated animal was subimited to 3 different treatments, with administration of 50.000, 100.000 and 300.000 particles of MAA. The obtained images with diverse radiopharmaceutical doses were qualitative and quantitative compared, including in this the evaluation of radiopharmaceutical distribution and the homogeneity index. There were observed no significative differences between the images during the visual evaluation and calculation of the relative quantification of the lung perfusion. However, the integral uniformity calculation demonstrated significative difference at the homogeneity of the lung image between the different MAA doses. That leads to the conclusion that there is an increase at the images homogeneity directly related to the number of albumin macroaggregated particles injected, though difference has not been realized by the qualitative analysis.
412

Efeitos da poluição do ar sobre a função pulmonar: um estudo de coorte em crianças de Cubatão / Effects of air pollution on lung function: a cohort study in Cubatão children

Hofmeister, Vera Anna 11 September 1991 (has links)
É feita a análise da evolução de provas funcionais ventilatórias de dois grupos de crianças clinicamente sadias, residentes no Município de Cubatão, examinadas inicialmente em dois estudos transversais realizados respectivamente em 1983 (verão) e em 1985 (inverno). O princípio epidemiológico que norteou essa pesquisa foi a realização de um estudo de Coorte Não-Controlada, ou mais apropriadamente, um Estudo Ecológico Longitudinal, onde esses dois grupos de crianças foram anualmente submetidos a exames espirométricos no período de 1987 a 1989, mantida a estrita sazonalidade, ou seja, o Grupo de 1983 foi sempre reexaminado no verão, enquanto que o Grupo de 1985 sempre no inverno. Aproximadamente 1.110 crianças, oriundas de todas as áreas do Município foram submetidas a provas de função pulmonar utilizando-se espirômetro seco, com especial ênfase na análise do comportamento da Capacidade Vital Forçada (CVF), do Volume Expiratório Forçado no Primeiro Segundo (VEF1,0), do \"Peak-Flow\" ou Pico de Fluxo Expiratório (PFE), e do Fluxo Médio Expiratório Forçado (FMF25-75 por cento ), todos considerados como indicadores sensíveis às influências dos níveis de poluição atmosférica registrados em Cubatão. As informações concernentes à poluição do ar foram obtidas através dos relatórios de pesquisas efetuadas pela Companhia de Tecnologia de Saneamento Ambiental do Estado de São Paulo (CETESB) e envolveram a análise das estimativas de emissões das indústrias prioritárias de Cubatão, das concentrações horárias de material particulado (MP), dióxido de enxofre (SO2) e do ozona (O3) registradss nas estações amostradoras de Vila Parisi, Cubatão-Centro e Vila Nova no período de Novembro de 1983 a Dezembro de 1989. Também integrou o contexto de análise, a avaliação das principais metas do Programa de Controle de Poluição do Ar instituído pela CETESB na região a partir de 1984, com o objetivo de se verificar se as reduções pretendidas nos níveis de poluição do ar se fizeram acompanhar de melhorias nas provas funcionais pulmonares das crianças estudadas. Verificou-se que os episódios agudos de poluição do ar, principalmente devidos ao material particulado, mostraram algum decréscimo. No entanto, aqueles devidos a oxidantes fotoquímicos, representados pelos níveis de ozona, tiveram progressivo incremento no período de 1984 a 1988, tanto em relação ao número de episódios, como na persistência e gravidade dos mesmos. Os resultados espirométricos indicaram que em ambos os grupos de crianças a função pulmonar mostrou decrementos significativos, com perdas em tomo de 5 a 8 por cento ao ano, em média, quando comparados com os valores inicialmente registrados por ocasião dos estudos transversais. Apesar das reduções terem sido observadas em todas as variáveis espirométricas, os maiores decrementos verificaram-se principalmente nas medidas de fluxo (PFE e FMF25_75 por cento ), e coincidiram com o ano em que foram assinalados os mais graves episódios de poluição devida a oxidantes fotoquímicos. Os bairros Cota 95, Cota 200, Jardim das Indústrias e Vila Natal, localizados na área de influência do núcleo industrial químicofpetroquímico sobressairam-se como os mais críticos em função dos piores resultados espirométricos apresentados ao longo de todo o estudo. Pôde-se concluir que apesar da função pulmonar das crianças ainda não ter atingido níveis considerados como patológicos, mesmo registrando valores inferiores aos limites da normalidade nas variáveis de fluxo no ano de 1988, verificou-se que de ano para ano a função pulmonar vem decrescendo progressivamente indicando que esta vai sendo afetada pela exposição as poluentes da região e que as medidas de controle da poluição instituídas em Cubatão não tiveram a eficácia esperada. Continuando nessa mesma trajetória evolutiva, isso poderá acarretar sérios e irreparáveis prejuízos à saúde da população. É necessário, portanto, a adoção de urgentes medidas para a melhoria da qualidade do ar em Cubatão nos anos futuros, no intuito de prevenir sérios agravos à Saúde Pública. / The purpose of this study was to investigate the effects of exposure to air pollution on lung function of children. Two groups of clinically healthy children, living at different areas of the city of Cubatão, who had been submitted to lung function tests in a previous cross-sectional study (1983 summertime and 1985 wintertime) were annually reexamined using the same type of test during the period 1987 to 1989. On epidemiological basis this is a longitudinal study, where every individual of the two groups of children was measured at each ocasion, always in the same season of the previous examination. About 1,110 children from all areas of the city were examined once a year using dry spirometer, with special emphasis on FVC, FEV 1,0, PEF and FMF25-75 per cent measurements, since they were considered as those which could be most affected by the local air pollution. Information regarding the conditions of air pollution were obtained from the CETESB\'s written reports. They include the estimate emissions of the main industries of the region; the hourly concentrations of particulate matter, sulfur dioxide and ozone measured in the sampling stations located in Vila Parisi, Cubatão-Centro and Vila Nova during the October/1983 to December/1989 period and also the results of the Source Control Strategy introduced by CETESB since 1984. It was observed that the acute episodes of air pollution due to PM were reduced in number. However, those due to photochemicaf oxidants, mainly represented by ozone leveis, were progressively more frequent during the period from 1984 to 1988; both their number and their severity increased during this period. Spirometric results shows that in both groups of children the lung function was significantly impaired, with losses of 5 to 8 per cent per year, when compared with the initial values of the cross-sectional studies. Despite the fact that all lung function parameters decline, the flow (PFE and FMF2s-7s per cent ) values were those most affected and closely related to the most serious episodes of air pollution due to photochemical oxidants mainly those observed in 1988. Children living in the areas of Cota 95, Cota 200, Jardim das Indústrias and Vila Natal, situated in the nearest area of influence of the chemical and petrochemical industries, presented worst spirometric results than children living in other places of Cubatão. The lung function of the examined children did not attain pathological values, despite the fact of presenting the worst results in flow parameters during the year of 1988. It was observed that their lung function is progressively impaired year by year, a clear indication of the progressive effects of air pollution on their lung function, and if such impairment continues there will carne the time when lung function will probably reach a pathologicallevel. It is concluded that there is an urgent need of improving the quality of air of Cubatão to avoid serious Public Health problems in a quite near future.
413

Efeitos da hiperprolactinemia sobre a inflamação alérgica pulmonar em ratos Wistar / Effects of hyperprolactinemia and pulmonary allergic inflammation in rats

Amaya, Julieta Esperanza Ochoa 26 January 2016 (has links)
Objetivo: Foi investigada a hipótese da hiperprolactinemia modular a resposta inflamatória alérgica pulmonar em ratos machos e em fêmas lactantes sem tratamento de domperidona. Métodos: Em ratos machos, a hiperprolactinemia foi de curta duração (5 dias) induzida pela domperidona (5,1 mg.kg-1 por dia, i.p). A resposta alérgica foi gerada por sensibilização e desafios inalatórios com ovoalbumina. Foi feita contagem de leucócitos totais e diferenciados do lavado bronco alveolar (BAL), lavado medular femoral (BFL) e sangue; a percentagem de produção de muco e colageno no pulmão, níveis de corticosterona e prolactina e citocinas TNF-α, IL-4, IL-6, IL-10, em explantes de pulmão e IFNg no BAL, foram medidos. Pela citometria foram avaliadaos os receptores de prolactina; Resultados: Hiperprolactinemia de curta duração feita antes do desafio inalatório disminuiu a resposta alérgica pulmonar na contagem de leucócitos no lavado broncoalveolar. Esse tratamento reduziu a celularidade no BFL e a percentagem de muco e aumentou a expressão de citocinas IL-4, IL-6, IL-10, TNFα e da expressão do IFNg. Níveis altos de prolactina diminuiram o número de eosinófilos ao pulmão no BAL. Pela citometria revelou-se que além de ter menor número de granulócitos migrados ao pulmão, estes apresentaram maior expressão do número de receptores por granulócito para prolactina no grupo tratado com domperidona. Alterações similares foram reveladas em fêmeas lactantes como foi a diminuição nos leucócitos do BAL, e no número de células do BFL. O tratamento profilático diminuiu a resposta alérgica tanto no grupo hiperprolactinêmico como no grupo veículo. O tratamento feito após o desafio inalatório não evidenciou alterações relevantes nas variáveis medidas. Conclusões: A hiperprolactinemia de curta duração, feita após a sensibilização e antes da inalação diminui a resposta inflamatória no pulmão em ratos. Os resultados deste estudo demonstram que a hiperprolactinemia induzida antes do desafio antigênico diminue a inflamação alérgica pulmonar. Assim, é provável que a prolactina endógena tenha um papel relevante como um imunomodulador da asma. Este estudo aponta a possibilidade futura do uso da domperidona para pacientes asmáticos. Durante a primavera muitas espécies de mamíferos têm seus filhotes e ocorre abundância de fatores alergenos no ar. Logo, um fator endógeno que favoreça a proteção de fêmeas durante a lactação, tal como a hiperprolactinemia, tem elevado valor adaptativo / Objective: It was investigated if hyperprolactinemia has modulatory actions on lung allergic inflammatory response in male rats. Lactating female rats were tested for pulmonary allergy as well. Methods: In male rats, short-term (5 days) hyperprolactinemia was induced by domperidone (5.1 mg.kg-1 per day, ip). Allergic response was generated by sensitization and inhalation challenge with ovalbumin. Total and differential leukocytes bronchoalveolar lavage (BAL), femoral medullary lavage (BFL) and blood; the percentage of collagen and mucus production in the lungs, plasma levels of corticosterone and prolactin cytokines and TNF-α, IL-4, IL-6, IL-10, IFNg explants lung and BAL, were measured. Flow cytometry was used to evaluate prolactin receptor; Results: Short-term hyperprolactinemia made before the inhaled challenge reduced the pulmonary allergic response in white blood cell counts in BAL. This treatment reduced the cellularity in BFL and the percentage of mucus and increased expression of cytokines IL-4, IL-6, IL-10, TNFa and IFNg expression. High prolactin levels decreased the number of eosinophils to the lung in BAL. There were fewer granulocytes migrated to the lung. These granulocytes showed higher expression prolactin receptors in hyperprolactinemia animals. Similar changes were revealed in lactating females. In these animals, there was a reduction in BAL leukocyte, and the number of cells BFL. Prophylactic treatment decreased the allergic response in both hyperprolactinemic and vehicle groups. The treatment made after inhalational challenge did not induce significant changes in the variables measured in this study. Conclusions: Short-term hyperprolactinemia, made after sensitization and before inhalation, decreases the inflammatory response in the lung of rats. The results of this study demonstrate that hyperprolactinemia, induced before antigen challenge, decreases pulmonary allergic inflammation. Thus, it is probable that the endogenous prolactin has an important role as an immunomodulator of asthma. This study points out the prospect of a future use of domperidone for asthmatic patients. For various mammalian species, parturition occurs during springtime. Pollen in the air might be an abundant allergic factor during springtime. Thus, protecting lactating females against this type allergy might have high adaptive value
414

Determination of local oxygen consumption by healthy and diseased lungs in a rabbit model.

January 1999 (has links)
Gu Jia-Shi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 117-148). / Abstracts in English and Chinese. / Title --- p.i / Abstract (English) --- p.iii / Abstract (Chinese) --- p.iv / Acknowledgments --- p.v / Statement of Originality --- p.vi / List of Abbreviations --- p.viii / List of Figures --- p.xi / List of Tables --- p.xiii / Table of Contents --- p.xiv / Chapter Section One : --- Introduction & Literature Review / Introduction & Objective --- p.2 / Introduction / Objective of the present study / Chapter Chapter. 1 --- A Review of Chronic lung disease (CLD) --- p.6 / Chapter 1. --- BPD 226}0ؤ an example of CLD / Chapter 2. --- Pathological change & Clinical presentation / Chapter 3. --- Clinical sequel of CLD infants / Chapter 3.1 --- O2 consumption of CLD infants / Chapter 3.1-1 --- Oxygen consumption / Chapter 3.1-2 --- Oxygen transportation / Chapter 3.1-2a --- Dissolved O2 / Chapter 3.1-2b --- Haemoglobin / Chapter 3.2 --- Energy expenditure of CLD infants / Chapter 3.3 --- Growth rate of CLD infants / Chapter 4. --- Treatment & Management of CLD infants / Chapter 4.1 --- Diuretics / Chapter 4.2 --- Bronchodilators / Chapter 4.3 --- Corticosteroids / Chapter 5. --- "Interpretations of the observed phenomena, why does CLD impair growth?" / Chapter 5.1 --- The traditional view / Chapter 5.2 --- Disagreement with the traditional view / Chapter Chapter 2 --- Measurement of oxygen consumption --- p.20 / Chapter 1. --- Invasive measurement of VO2 / Chapter 1.1 --- Cardiac output / Chapter 1.2 --- Fick method / Chapter 1.3 --- Advantages and Disadvantages of Fick method in estimating VO2 / Chapter 1.4 --- Measurement of cardiac output by thermodilution / Chapter 1.4-1 --- Advantages and Disadvantages of Thermodilution Method / Chapter 2. --- Non-invasive measurement of VO2 / Chapter 2.1 --- Metabolic analyzer---DeltatraćёØII / Chapter 2.2 --- Paramagnetic sensor / Chapter 3. --- Measured and calculated oxygen consumption / Chapter 3.1 --- Difference between mVO2 and cVO2 / Chapter 4. --- Summary / Chapter Chapter 3 --- Hypothesis --- p.34 / Chapter 1. --- Possible explanations for the difference between mV02 & cV02 / Chapter 1.1 --- Measurement variability and Mathematical error / Chapter 1.2 --- Oxygen consumption of the lung / Chapter 1.3 --- VO2pul with lung damage / Chapter 1.4 --- "Neutrophils, Macrophages and oxygen consumption" / Chapter 2. --- Hypothesis / Chapter Section Two : --- Methods & Materials / Chapter Chapter 1 --- Animal Model --- p.41 / Chapter Chapter 2. --- Materials --- p.43 / Chapter 1. --- Animals / Chapter 2. --- Chemicals used for inducing lung damage / Chapter 2.1 --- Acute damage group / Chapter 2.1-1 --- N-nitroso-N-methylurethane (NNNMU) / Chapter 2.1-2 --- Administrations to rabbits / Chapter 2.2 --- Chronic damage group / Chapter 2.2-1 --- Bleomycin (BLM) / Chapter 2.2-2 --- Pulmonary toxicity of Bleomycin / Chapter 2.2-3 --- Administration to animals / Chapter Chapter 3 --- Instruments --- p.50 / Chapter 1. --- Measurement of VO2 and VCO2 226}0ؤDeltatracIÍёØ Metabolic analzyer / Measurement of cardiac outpu´tؤCardiomax II model85 / Chapter Chapter 4 --- Methods --- p.58 / Chapter 1. --- N-nitroso-N-methylurethane (NNNMU) Preparation / Chapter 2. --- Bleomycin Preparation / Chapter 3. --- 2.5% pentobarbitone Preparation / Chapter 4. --- Animal Preparation / Chapter 4.1 --- Control (Normal) group / Chapter 4.2 --- A cute lung damage group / Chapter 4.3 --- Chronic lung damage group / Chapter 5. --- Preparation of the animals for VO2 measurement / Chapter 6. --- Measurement of oxygen consumption / Chapter 6.1 --- VO2wb measurement / Chapter 6.2 --- VO2b measurement / Chapter 7. --- Histopathology / Chapter 8. --- Statistics / Chapter Section Three : --- Results --- p.69 / Chapter 1. --- Healthy (Control) group / Chapter 1.1 --- Pulmonary histology / Chapter 2. --- Acute lung damage group / Chapter 2.1 --- Pulmonary histology / Chapter 3. --- Chronic lung damage group / Chapter 3.1 --- Pulmonary histology / Chapter 4. --- Comparison of the pulmonary oxygen consumption among the three groups / Chapter Section Four : --- Discussion --- p.97 / Chapter Section Five : --- Conclusion --- p.111 / Chapter Section Six : --- Future Studies --- p.114 / Chapter Section Seven : --- Bibliography --- p.118
415

Assessment of Pseudomonas aeruginosa epidemiology and the wider microbial diversity within the bronchiectatic lung

Mitchelmore, Philip January 2018 (has links)
The bronchiectatic lung is a diseased state in which the airways are chronically damaged and dilated. This state is found in the clinical entities of cystic fibrosis and non-cystic fibrosis bronchiectasis. These are two highly relevant chronic suppurative lung diseases in which an understanding of the microbiology of these patients is considered key to appropriate management. This has traditionally been via the use of traditional culture techniques. However, with the development of molecular methodologies, the previously perceived wisdom is being challenged. In both cystic fibrosis and non-cystic fibrosis bronchiectasis, Pseudomonas aeruginosa is considered the most significant pathogen. In CF there has been considerable concern surrounding the risk of transmission of Pseudomonas aeruginosa between patients on the basis of a significant quantity of research into this matter. In contrast, there has been very little research performed into the equivalent risk in non-cystic fibrosis bronchiectasis. In this thesis we describe an extensive single-centre epidemiological review of Pseudomonas aeruginosa spanning both these diseases. Via this we have shown evidence of cross-infection within a non-cystic fibrosis bronchiectasis cohort. This epidemiological review has included multiple genotyping methods including multilocus sequence typing and whole genome sequencing, As an extension of the epidemiological review, we have performed an in silico prediction of hypermutator status from the whole genome sequencing data to provide greater understanding of the likelihood of cross-infection, and have also demonstrated a culture-independent adaption of multilocus sequence typing for potential screening for cross-infection. In addition to Pseudomonas aeruginosa, we have also looked at the wider bacterial community in the lungs of patients with these two conditions via culture-independent techniques. We have shown that whilst Pseudomonas aeruginosa is often an important component, these are clearly complex communities. We have primarily investigated the cohort with non-cystic fibrosis bronchiectasis, but we have demonstrated associations between clinically-relevant markers and complexity of the bacterial communities within the lungs of both these cohorts of patients. Whilst we have used the gold-standard technique of 16S rRNA sequencing, we have also shown the validity of a simple and potentially more feasible profiling technique for standard clinical care. In summary, through the application of culture-dependent and independent molecular techniques, this research has shed light on the epidemiology of Pseudomonas aeruginosa within our respiratory cohorts, and the complexity and clinical relevance of the wider microbial communities within these patients. Such studies are essential if we are to advance our understanding of the bronchiectatic lung and optimise strategies for patient management.
416

Radon and Lung Cancer

Gaskin, Janet 29 March 2019 (has links)
Background: Lung cancer was the fifth leading cause of mortality globally in 2010, and the leading cause of cancer mortality in Canada, representing 26% of all cancer deaths for both men and women in 2017. Radon is a very modifiable environmental exposure that is the second most important cause of lung cancer. Objectives: The objectives of this thesis are to quantify the lung cancer burden associated with residential radon and to identify the most cost effective mitigation options to reduce residential radon in Canada. Methods: The global burden of lung cancer mortality attributable to radon in 2012 was estimated from the 66 countries for which a representative national radon survey was available, using several different models for excess relative risk (ERR) of lung cancer from radon studies. Cost-utility analyses are conducted for 20 practical radon interventions scenarios to reduce residential radon exposures in new and existing housing in Canada, each province/territory and 17 census metropolitan areas. A societal perspective and a lifetime horizon are adopted. A Markov cohort model and a discrete event simulation are used to model residents by household, based on a period-life table analysis, at a discount rate of 1.5%. Results: The estimates of the global median PAR were consistent, ranging from 16.5% to 13.6% for the three ERR models based on miners, and the mean estimates of PAR for Canada ranged from 16.3% to 14.6%. It is very cost effective to install radon preventive measures in new construction compared to no radon control in all regions across Canada. At a radon mitigation threshold of 100 Bq/m3, the sequential analysis recommends the combination of the activation of preventive measures in new housing with the mitigation of existing housing at current testing and mitigation rates for cost effectiveness thresholds between 51,889 and 92,072 $/QALY for Canada, between 27,558 and 85,965 $/QALY for Manitoba, and between 15,801 and 36,547 $/QALY for the Yukon. The discounted ICER for screening and mitigation of existing housing at current rates relative to no radon control measures is 62,451 (66,421) $/QALY using a Markov cohort model (discrete event simulation model) for mitigation of housing above a threshold of 200 Bq/m3, and is 58,866 (59,556) $/QALY using a Markov cohort model (discrete event simulation model) for mitigation of housing above a threshold of 100 Bq/m3. Conclusions: Cost effective residential radon interventions should be implemented across Canada to reduce exposures to this very modifiable cause of lung cancer and to help reduce the increasing lung cancer burden in an ageing Canadian population.
417

Desenvolvimento de nanocápsulas poliméricas contendo erlotinib e avaliação do efeito antitumoral in vitro em células de adenocarcinoma de pulmão / Development of erlotinib-loaded nanocapsules and evaluation of the in vitro antitumor effect in lung adenocarcinoma cells

Bruinsmann, Franciele Aline January 2016 (has links)
Objetivos: Desenvolver e caracterizar nanocápsulas poliméricas contendo erlotinib, bem como avaliar sua atividade antitumoral in vitro em células de adenocarcinoma de pulmão humano. Metodologia: As nanocápsulas contendo erlotinib (0,5 mg.mL-1) foram obtidas pelo método de nanoprecipitação utilizando poli(ε-caprolactona) e óleo de copaíba como parede polimérica e núcleo oleoso, respectivamente. Os parâmetros físico-químicos avaliados foram: diâmetro médio e distribuição de tamanho, índice de polidispersão, potencial zeta, concentração de partículas e pH. Para determinação do teor e eficiência de encapsulação do erlotinib, utilizou-se metodologia validada por CLAE-UV. O estudo de liberação in vitro, utilizando sacos de diálise, foi realizado para obter o perfil de liberação do fármaco a partir das nanocápsulas. As nanocápsulas contendo erlotinib foram avaliadas quanto ao seu potencial de inibir o crescimento, induzir a apoptose, interferir com o ciclo celular e sobrevivência clonogênica de células de adenocarcinoma de pulmão, linhagem A549. Resultados: As nanocápsulas apresentaram diâmetro médio de 171 ± 2 (PDI < 0, 10), potencial zeta de −8,17 ± 2.26 mV, número de partículas por mL de 6,97 ± 0,22 × 1013 e pH de 6,24 ± 0,02. O teor e a eficiência de encapsulação foram próximos de 100%. Com exceção do pH, todos parâmetros mantiveram-se iguais após 30 dias de armazenamento em temperatura ambiente. Observou-se uma liberação controlada do fármaco devido à nanoencapsulação. Os ensaios de citotoxicidade demonstraram que as nanocápsulas contendo erlotinib apresentaram maior atividade antitumoral quando comparado com o fármaco livre. Também foi demonstrado indução de apoptose, pela análise de ciclo celular e marcação por Anexina-V conjugada ao 7-AAD. No ensaio clonogênico, as nanocápsulas contendo erlotinib reduziram 100% o número de colônias formadas. Conclusões: Foram obtidas nanocápsulas com propriedades nanotécnologicas adequadas e capazes de controlar a liberação do erlotinib. Os estudos in vitro na linhagem celular A549 demonstraram aumento no efeito antitumoral e foi demonstrado que o encapsulamento do fármaco é imprescindível para essa melhor atividade. / Purpose: To develop and characterise erlotinib-loaded polymeric nanocapsules and to evaluate its in vitro antitumor activity in human lung adenocarcinoma cells. Methodology: The erlotinib-loaded nanocapsules (0.5 mg.mL-1) were obtained by nanoprecipitation method using poly (ε-caprolactone) and copaiba oil as the polymeric wall and oily core, respectively. The physicochemical parameters evaluated were: mean diameter and size distribution, polydispersity index, zeta potential, particle concentration and pH. An HPLC-UV validated method was used to determine the drug content and encapsulation efficiency. The in vitro release study using dialysis bags was performed to obtain the drug release profile from nanocapsules. The erlotinib-loaded nanocapsules were evaluated regarding their potential to inhibit the growth, induce apoptosis, interfere with the cell cycle and clonogenic survival of lung adenocarcinoma cell (A549). Results: The nanocapsule formulation presented z-average diameter of 171 ± 2 (PDI <0.10), zeta potential value of -8.17 ± 2.26 mV, number of particles per mL of 6.97 ± 0.22 × 1013, and pH value of 6.24 ± 0.02. The drug content and the encapsulation efficiency were nearly 100%. Except for the pH value, all these parameters remained the same after 30 days of storage. A controlled release of the drug was observed due to nanoencapsulation. The cytotoxicity assays demonstrated that the erlotinib-loaded nanocapsules showed higher antitumor activity compared to free drug. Induction of apoptosis was demonstrated by cell cycle analysis and Annexin-V/7AAD staining. In the clonogenic assay, erlotinib-loaded nanocapsules reduced 100% the number of colonies formed. Conclusions: Nanocapsules with appropriate nanotechnological properties and capable of controlling the erlotinib release were obtained. The in vitro studies in the A549 cell line showed an increase in antitumor effect and was demonstrated that the drug encapsulation is essential for this better activity.
418

Hyperoxia-induced lung damage in premature rat. / CUHK electronic theses & dissertations collection

January 1999 (has links)
Xu Feng. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (p. 205-233). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
419

Involvement of innate immune humoral factors, CFHR5 and SP-D, in glioblastoma multiforme

De Cordova, Syreeta January 2017 (has links)
Glioblastoma Multiforme (GBM) is an extremely aggressive grade IV brain tumour that is highly infiltrative and can spread to other parts of the brain quickly. It is the most common primary brain tumour where patients have a median survival of 14.6 months. Symptoms vary depending upon the location of the tumour and include seizures, progressive headaches and focal neurological deficit. The poor prognosis is characterised by deregulation of many key signalling pathways involving survival, growth, apoptosis and evasion of immune surveillance. In this study, we investigated whether complement factor H related protein 5 (CFHR5) from primary GBM cells direct from patients exhibited functional activity similar to factor H. The presence of CFHR5 was validated by western blot and ELISA technique from B30, B31 and B33 primary GBM cells. The functional capacity of CFHR5 was examined through the alternative pathway, co-factor, and decay acceleration assay. We demonstrated that CFHR5 was able to inhibit the alternative pathway through the same mechanism as factor H. Emerging evidence had shown that the innate immune protein surfactant protein D (SP-D) and recombinant human SP-D (rhSP-D) were able to induce apoptosis in eosinophilic leukaemic cells. We studied the ability of rhSP-D to induce apoptosis in U87 GBM cells through apoptotic and viability assays. rhSP-D was unable to mediate cell death and instead increased cell viability. This led us to investigate the expression of SP-D in U87 and B30 GBM cells through western blot, ELISA and immuno-fluorescence detection. We demonstrated novel information about the production of SP-D by GBM cells. To extend our study, we investigated the interaction of THP-1 macrophage with rhSP-D bound U87 cells. We carried out live cell imaging, RT-qPCR, and cell viability assays, to study the changes in cytokine expression and viability of cells. THP-1 did not engulf U87 cells; however, it did reduce the number of cells and decrease the expression of pro-tumourigenic cytokines. This study highlights the ability of primary GBM cells to evade innate immune detection by the secretion of functionally active CFHR5. It also demonstrated the ability of U87 to evade destruction by rhSP-D and THP-1 highlighting the extremely aggressive behaviour of the tumour and lack of new treatment to improve prognosis in over a decade.
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Inverse problems and control for lung dynamics

Tregidgo, Henry January 2018 (has links)
Mechanical ventilation is vital for the treatment of patients in respiratory intensive care and can be life saving. However, the risks of regional pressure gradients and over-distension must be balanced with the need to maintain function. For these reasons mechanical ventilation can benefit from the regional information provided by bedside imaging such as electrical impedance tomography (EIT). In this thesis we develop and test methods to retrieve clinically meaningful measures of lung function from EIT and examine the feasibility of closing the feedback loop to enable EIT-guided control of mechanical ventilation. Working towards this goal we develop a reconstruction algorithm capable of providing fast absolute values of conductivity from EIT measurements. We couple the resulting conductivity time series to a compartmental ordinary differential equation (ODE) model of lung function in order to recover regional parameters of elastance and airway resistance. We then demonstrate how these parameters may be used to generate optimised pressure controls for mechanical ventilation that expose the lungs to minimal gradients of pressure and are stable with respect to EIT measurement errors. The EIT reconstruction algorithm we develop is capable of producing low dimensional absolute values of conductivity in real time after a limited additional setup time. We show that this algorithm retains the ability to give fast feedback on regional lung changes. We also describe methods of improving computational efficiency for general Gauss-Newton type EIT algorithms. In order to couple reconstructed conductivity time series to our ODE model we describe and test the recovery of regional ventilation distributions through a process of regularised differentiation. We prove that the parameters of our ODE model are recoverable from these ventilation distributions apart from the degenerate case where all compartments have the same parameters. We then test this recovery process under varying levels of simulated EIT measurement and modelling errors. Finally we examine the ODE lung model using control theory. We prove that the ODE model is controllable for a wide range of parameter values and link controllability to observable ventilation patterns in the lungs. We demonstrate the generation and optimisation of pressure controls with minimal time gradients and provide a bound on the resulting magnitudes of these pressures. We then test the control generation process using ODE parameter values recovered through EIT simulations at varying levels of measurement noise. Through this work we have demonstrated that EIT reconstructions can be of benefit to the control of mechanical ventilation.

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