Vascular corrosion casts of normal and elastaseinduced emphysemic hamster lungs, prepared with a low viscosity resin mixture consisting of Mercox and Sevriton, were observed by scanning electron microscopy. Casts were quantitated by measuring vascular volume or determining nonalveolar air space using confocal laser scanning microscopy. Normal lung casts were characterized by wellorganized fields of alveoli (about 70m in diameter) connected by distinct alveolar ducts. Emphysemic lung casts exhibited numerous bullae (often as large as 0.5 mm in diameter). The vasculature of the bullae indicated that they were formed by destruction of alveolar walls and subsequent coalescence of numerous alveolae. Remnants of alveolar walls, consisting of shallow ridges of capillaries, lined the bases of the bullae. Vascular volumes expressed as cast volume/total tissue volume were calculated at 20% and 12% for uninflated and inflated lungs, respectively, for both control and emphysemic lungs. Four months after elastase instillation, nonalveolar air space of the emphysemic lungs was increased by 73% over controls. These observations indicate that elastase emphysema results, initially, in remodeling of the alveolar structure (bullae formation) and loss of surface area for gas exchange, rather than from extensive loss of vasculature. Vascular corrosion casting is a useful technique for monitoring emphysema both morphologically and quantitatively.

Medical imaging is widely used in current healthcare and research settings for various purposes such as diagnosis, treatment options, patient monitoring, longitudinal studies, etc. The two most commonly used imaging modalities in the United States are Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). Raw images acquired via CT or MRI need to undergo a variety of processing steps prior to being used for the purposes explained above. These processing steps include quality control, noise reduction, anatomical segmentation, tissue classification, etc. However, since medical images often include millions of voxels (smallest 3D units in the image containing information) it is extremely challenging to process them manually by relying on visual inspection and the experience of trained clinicians. In light of this, the field of medical imaging is seeking ways to automate data processing. With the impressive performance of Artificial Intelligence (AI) in the field of Computer Vision, researchers in the medical imaging community have shown increasing interest in utilizing this powerful tool to automate the task of processing medical imaging data. Despite AI’s significant contributions to the medical imaging field, large cohorts of data still remain without optimized and robust AI-based tools to process images efficiently and accurately. This thesis focuses on exploiting large cohorts of CT and MRI data to design AI-based methods for processing medical images using weakly-supervised and supervised learning strategies, as well as mathematical (and/or statistical) modeling and signal processing methods. In particular, we address four image processing problems in this thesis. Namely: 1) We propose a weakly-supervised deep learning method to automate binary quality control of diffusion MRI scans into ‘poor’ and ‘good’ quality classes; 2) We design a weakly-supervised deep learning framework to learn and detect visual patterns related to a set of different artifact categories considered in this work, in order to identify major artifact types present in dMRI volumes; 3) We develop a supervised deep learning method to classify multiple lung texture patterns with association to Emphysema disease on human lung CT scans; 4) We investigate and characterize the properties of two types of negative BOLD response elicited in human brain fMRI scans during visual stimulation using mathematical modeling and signal processing tools. Our results demonstrate that through the use of artificial intelligence and signal processing algorithms: 1) dMRI scans can be automatically categorized into two quality groups (i.e., ‘poor’ vs ‘good’) with a high classification accuracy, enabling rapid sifting of large cohorts of dMRI scans to be utilized in research or clinical settings; 2) Type of the major artifact present in ‘poor’ quality dMRI volumes can be identified robustly and automatically with high precision enabling exclusion/correction of corrupt volumes according to the artifact type contaminating them; 3) Multiple lung texture patterns related to Emphysema disease can be automatically and robustly classified across various large cohorts of CT scans enabling investigation of the disease through longitudinal studies on multiple cohorts; 4) Negative BOLD responses of different categories can be fully characterized on fMRI data collected from visual stimulation of human brain enabling researchers to better understand the human brain functionality through studying cohorts of fMRI scans.

Emphysema is a condition of the lung characterized by abnormal, permanent enlargement of the airspaces distal to the terminal bronchiole, accompanied by a destruction of their walls. The primary pathogenesis of emphysema is poorly understood. One of the major issues of COPD is that no diagnostic tests are sensitive enough to detect early disease. Standard pulmonary function tests (PFTs) do not explain the underlying pathophysiology of airflow limitation, nor do they provide information on how COPD may be affecting pulmonary blood flow. Functional imaging, specifically ventilation and perfusion (V/Q) Single Photon Emission Computed Tomography (SPECT), is a sensitive tool that can provide information on pulmonary function in different lung regions. When V/Q images are co-registered to CT, regional analysis can be coupled to structural information. The objective of this study was to examine how emphysematous change identified and localized by CT density based thresholds affects lung function as measured by V/Q SPECT in a mouse model of the disease. A dose response study was conducted where Female BALB/c mice were exposed intranasally to 0.0, 0.5, 2.5 and 5.0 units (U) of porcine pancreatic elastase (PPE). V/Q SPECT/CT scanning was performed 45 days post exposure, followed by measurement of lung compliance using the Flexivent® rodent ventilator 46 days post exposure. Whole lung slice analysis software was used to quantify airspace enlargement and alveolar capillary density from histological sections of the lung. CT pulmonary angiography (CTPA) was also performed on controls and mice exposed to 5 U PPE to examine vascular density. In this mouse model of emphysema, V/Q SPECT was useful in quantitatively examining how ventilation and perfusion is affected in mild and severe emphysema while providing evidence of low log(V/Q) ratio in otherwise normal lung densities. This could be caused by airflow obstruction as a result of widespread narrowing or loss of small conducting airways. Low log(V/Q) ratio is caused by mild emphysema indicating airflow obstruction or dysfunctional hypoxic vasoconstriction in underventilated regions of the lung. The majority of severely emphysematous regions of the lung have matched but equally reduced log(V/Q), although low log(V/Q) is also present. Pulmonary hypertension in response to chronic hypoxia may explain our finding of reduced perfusion activity and vascular density in emphysematous lung, but further research is required to investigate the presence of this pathology. V/Q SPECT was also shown to be superior in the detection of emphysema compared to CT and Flexivent measured lung compliance providing evidence towards shifting the current assessment and monitoring paradigms. Due to the widespread availability of this imaging technique, it could be used to screen asymptomatic smokers for early disease and identify and locate pathology so therapies targeting the appropriate disease pathway can be prescribed. This will inevitably improve patient care. / Thesis / Master of Science (MSc)

Emphysema is an incurable lung airway disease and a hallmark of Chronic Obstructive Pulmonary Disease (COPD). In recent decades, Computed Tomography (CT) has been used as a powerful tool for the detection and quantification of different diseases, including emphysema. The use of CT comes with a potential risk: ionizing radiation. It involves a trade-off between image quality and the risk of radiation exposure. However, early detection of emphysema is important as emphysema is an independent risk marker for lung cancer, and it also possesses evident qualities that make it a candidate for sub-classification of COPD. In this master's thesis, we use state-of-the-art deep learning models for pulmonary nodule detection to classify emphysema at an early stage of the disease's progression. We also demonstrate that deep learning denoising techniques can be applied to low-dose CT scans to improve the model's performance. We achieved an F-score of 0.66, an AUC score of 0.80, and an accuracy of 81.74%. The impact of denoising resulted in an increase of 1.57 percent units in accuracy and a 0.0332 increase in the F-score. In conclusion, this makes it possible to use low-dose CT scans for early detection of emphysema with State-of-The-Art deep-learning models for pulmonary nodule detection.

Indiana University-Purdue University Indianapolis (IUPUI) / The complex pathogenesis of emphysema involves disappearance of alveolar structures, in part attributed to alveolar cell apoptosis. The mechanism by which cigarette smoke (CS) induces alveolar cell apoptosis is not known. We hypothesized that ceramides are induced by CS via specific enzymatic pathways that can be manipulated to reduce lung cell apoptosis. CS increased ceramides in the whole lung and in cultured primary structural lung cells. Exposure to CS activated within minutes the acid sphingomyelinase, and within weeks the de novo- ceramide synthesis pathways. Pharmacological inhibition of acid sphingomyelinase significantly attenuated CS-induced apoptosis. To understand the mechanisms by which ceramides induce apoptosis, we investigated the cell types affected and the involvement of RTP801, a CS-induced pro-apoptotic and pro-inflammatory protein. Direct lung augmentation of ceramide caused apoptosis of both endothelial and epithelial type II cells. Ceramide upregulated RTP801 and the transgenic loss of RTP801 inhibited only epithelial, but not endothelial cell apoptosis induced by ceramide. In conclusion, CS induces acid sphingomyelinase-mediated ceramide upregulation and apoptosis in a cell-specific manner, which in epithelial cells involves induction of stress response proteins that may further amplify lung injury. Molecular targeting of amplification pathways may provide therapeutic opportunities to halt emphysema progression.

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and is a risk factor for lung cancer development. COPD encompasses both emphysema and chronic bronchitis, the pathogenesis of which are unclear. In this dissertation, I leveraged genome-wide gene-expression studies of emphysema and lung cancer to investigate pathogenesis and carcinogenesis in COPD. Tobacco smoke is the primary cause of emphysema. The most severe form is also associated with alpha1-antitrypsin deficiency (AATD) resulting from a mutation. In this study, I leveraged multiple lung samples from patients with emphysema, with or without AATD. While genes involved in tissue repair decreased with emphysema severity, the unfolded protein response (UPR) was uniquely changed in AATD lungs. AATD may play multiple roles in emphysema and UPR activation suggests AAT replacement therapy may be insufficient to treat this form of emphysema. Emphysema is a progressive disease, and the mean linear intercept (Lm) can serve as a surrogate of progression. I evaluated whether Lm increases in non-diseased lungs may represent similar processes to those occurring in emphysema, and could offer insight into early stages of disease or homeostasis. Genes involved in tissue repair increased with Lm in controls but decreased in disease. Tissue repair processes may be active in even the non-insulted lung, suggesting their activity is necessary for lung homeostasis and their deficiency may drive emphysema progression. Finally, COPD patients are at increased lung cancer risk, and transcriptomic changes common to both diseases could explain this risk. In both COPD and lung cancer, I discovered that H3K27Me3 regulated genes are repressed, and that the methyltransferase responsible for H3K27me3, EZH2, is induced. H3K27Me3, an oncogenic histone modification, may drive carcinogenesis and pathogenesis in COPD. Though usual and AATD emphysema share transcriptomic signatures associated with tissue repair, which may be active in the normal homeostatic lung, the UPR changes in AATD emphysema only; successful therapeutic strategies in emphysema will need to account for this difference. In COPD, H3K27Me3 may play a role in both pathogenesis and carcinogenesis, making it an attractive target for therapeutic interventions, but one that would need further augmentation in AATD. / 2019-11-01T00:00:00Z

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24967号 / 医博第5021号 / 新制||医||1069(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊達 洋至, 教授 江木 盛時, 教授 川上 浩司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Cardiovascular disease is common in Chronic Obstructive Pulmonary Disease (COPD), and forced expiratory volume in one second (FEV1) independently predicts cardiovascular morbidity and mortality. Pathological changes in the systemic vasculature have been proposed as potential mechanisms linking COPD to cardiovascular disease, and patients with COPD may be at increased risk of acute myocardial infarction during acute exacerbations. Notwithstanding causation, FEV1 may be a useful prognostic marker in patients undergoing cardiac surgery. This thesis examined these three aspects of cardiovascular co-morbidity in relation to COPD and FEV1. In 2,241 consecutive cardiac surgery patients, FEV1 was associated with length of hospital stay (p<0.001) and mortality (p<0.001) adjusting for age, sex, height, body mass index, socioeconomic status, smoking, cardiovascular risk factors, chronic pulmonary disease, and type/urgency of surgery. In a survey of Scottish Respiratory Consultants there was no consensus regarding the investigation and management of acute coronary syndrome in exacerbation of COPD. In a case-series of 242 patients with exacerbations 2.5% (95% CI 1.0 to 5.6%) had chest pain, raised serum troponin and serial electrocardiogram changes suggestive of acute coronary syndrome. However, over half reported chest pain, while raised troponin was not associated with chest pain or serial ECG changes. Carotid-radial pulse wave velocity (PWV), aortic distensibility, and aortic calcification were measured to assess the relationship of the systemic vasculature to FEV1 and emphysema severity on CT. In adjusted analyses, emphysema was associated with PWV in patients with COPD (p = 0.006) and, in population based samples, with extent of distal aortic calcification (p=0.02) but not with aortic distensibility (p=0.60). This thesis found that FEV1 was associated with mortality and length of hospital stay in patients undergoing cardiac surgery, and that chest pain and raised troponin were common but unrelated in exacerbation of COPD. In the vascular studies distal but not proximal vascular pathology was associated with FEV1, and if COPD is truly related to systemic arterial disease, the distal arterial tree is implicated.

Pulmonary emphysema is a serious worldwide illness, causing progressive and irreversible alveolar wall loss and difficulty in breathing. It is caused mostly by cigarette smoking. However, its unresolved complex and multiple pathogenic mechanisms have left this disease without effective pharmacotherapy. This project hypothesized that cinnamic acid-based dehydropolymers (DHPs), originally discovered as novel anti-coagulants, protect against emphysema through their potent triple inhibitory actions against oxidative stress, inflammation and elastase, some of the pathogenic mechanisms associated with this disease. Three in vitro inhibitory activity assays for oxidative stress, lung inflammation and neutrophil elastase (NE) were developed and used to identify the most potent triple inhibitor DHP. These activities were determined by chromogenic free radical generation in chemical oxidation, lung epithelial (Calu-3) repression of pro-inflammatory nuclear factor κB (NFκB) upon its plasmid transfection and chromogenic substrate NE hydrolysis, respectively. The sulfated caffeic acid DHP, CDS was shown to be the most potent in all three assessments, yielding the half-maximal inhibitory concentrations of 3.52, ~10 and 0.43 µM, respectively. CDS was tested with pulmonary delivery in an in vivo rat model of emphysema induced by elastase and cigarette smoke extract (HSE/CSE). CDS at 5 and 30 μg/kg was instilled into the lung at 2 h prior to HSE/CSE instillation. The lung tissues and bronchoalveolar lavage fluids (BALFs) were taken 1 or 48 h post-HSE/CSE instillation to determine the tissue reduced glutathione (rGSH), airway infiltration of inflammatory neutrophils and airway luminal elastase alongside lung hemorrhage. The HSE/CSE instillation significantly caused 43.0 % decrease in rGSH, 104.8-fold greater neutrophil infiltration, 2.8-fold higher elastase activity and 9.3-fold increased lung hemorrhage, compared to the saline (negative) control. However, all these inductions were significantly protected by CDS at 30 μg/kg, exhibiting 92.9, 76.6, 59.7 and 70.4 % inhibition, respectively; reduced effects were seen at 5 μg/kg, showing its dose-related responses. As a result, the HSE/CSE-induced airspace enlargement assessed on 28th day was also prevented by CDS at 30 μg/kg, yet not at 5 μg/kg. In conclusion, this study has demonstrated the in vitro and in vivo effectiveness of CDS for its possible use in the protection against emphysema development, specifically via inhalation.

Introdução: A Síndrome Metabólica (MS) é uma comorbidade frequentemente encontrada nos pacientes que apresentam Doença Pulmonar Obstrutiva Crônica (DPOC). A DPOC e a MS possuem características em comum e o tabagismo é um fator de risco comum à DPOC e à MS. Apesar da intricada associação entre a DPOC e a MS, sabe-se muito pouco a respeito de como a co-ocorrência da MS afeta a resposta da DPOC ao treinamento físico - um tratamento efetivo para MS e que tem efeito protetor contra o enfisema induzido por tabaco - e à história natural desta. Objetivo: Avaliar como a ingestão crônica de frutose interfere na história natural e nos efeitos do treinamento físico aeróbio sobre a lesão pulmonar induzida por fumaça de cigarro. Métodos: Camundongos C57Bl/6 machos foram divididos em oito grupos (n=16-20/grupo): Controle, Fumo, Exercício, Fumo+Exercício, Frutose, Frutose+Fumo, Frutose+Exercício e Frutose+Fumo+Exercício; e expostos à fumaça de cigarro (30 minutos, 2x/dia), exercício físico (1 hora/dia) ou frutose (20% em água de beber) durante 12 semanas. Após o período de tratamento os animais foram anestesiados, submetidos à avaliação da mecânica respiratória e eutanasiados para coleta de sangue, lavado broncoalveolar (LBA), pulmões e músculos quadríceps para posteriores análises de histologia, dosagem de citocinas e avaliações de expressão gênica e estresse oxidativo. Resultados: A ingestão de frutose causou destruição do septo alveolar comparável com aquela causada pelo fumo (p < 0,001). A combinação de frutose e fumo produziu uma destruição alveolar mais severa do que qualquer um deles sozinho (p=0,008). O exercício físico inibiu o aumento do número total de células inflamatórias e macrófagos no LBA (p < 0,001), impediu o aumento dos níveis de interleucina (IL)-6, IL-10, IL-1beta, TNF-alfa, adiponectina e leptina no plasma e/ou músculo esquelético (p < 0,001), alterou a porcentagem de fibras colágenas e elásticas no parênquima pulmonar (p < 0,001) e atenuou o desenvolvimento do enfisema no grupo Frutose+Fumo+Exercício. Não houve efeito do exercício físico na mecânica respiratória, expressão de genes antioxidantes e estresse oxidativo. Conclusão: O treinamento físico aeróbio atenuou parcialmente o desenvolvimento do enfisema pulmonar em camundongos expostos à fumaça de cigarro e à frutose / Introduction: The Metabolic Syndrome (MS) is a comorbidity frequently presented by patients with Chronic Obstructive Pulmonary Disease (COPD). COPD shares with MS common features and tobacco use is a risk factor for both COPD and MS. Despite of this intricate association between COPD and MS, very little is known about how co-occurrence of MS might affect the response of COPD to physical exercise - an effective treatment for MS that has a protective effect against tobacco-induced COPD - and its natural history. Objective: To evaluate how chronic fructose intake interferes in the natural history and in the effects of aerobic exercise training on lung injury induced by exposure to CS. Methods: Male C57Bl/6 mice were assigned to 8 groups: Control, Smoke, Exercise, Smoke+Exercise, Fructose, Fructose+Smoke, Fructose+Exercise and Fructose+Smoke+Exercise (n=16-20/group) and treated accordingly with CS (30min twice/day), exercise training (1h/day) or fructose (20% in the drinking water) for 12 weeks. After the treatment period the animals were anesthetized, submitted to the evaluation of respiratory mechanics and were euthanized for collect of blood plasma, bronchoalveolar lavage fluid (BALF), lungs and quadriceps muscles for subsequent histology analysis and measures of cytokine levels, gene expression and oxidative stress. Results: Fructose ingestion caused destruction of alveolar septa comparable to that caused by the CS (p < 0,001). Combination of fructose and CS caused an alveolar destruction even more severe than either one alone (p=0,008). Exercise training inhibited the increase of the total number of inflammatory cells and macrophages in BALF (p < 0,001), inhibited the increase of the interleukin (IL)-6, IL-10, IL-1beta, TNF-alpha, adiponectin and leptin levels in plasma and/or skeletal muscle (p < 0,001), altered the percentage of collagen and elastic fibers in lung parenchyma (p < 0,001) and attenuated the development of emphysema in the Fructose+Smoke+Exercise group. There was no effect of exercise training on respiratory mechanics, antioxidant genes expression and oxidative stress. Conclusion: Aerobic exercise training partially attenuated the development of lung emphysema in mice exposed to cigarette smoke and fructose