This thesis examines the challenges of decellularizing porcine lungs. The thesis identifies hydrostatic pressure and the role it plays in perfusate distribution within the lung as a potential roadblock for the decellularization of porcine lungs. The thesis examines methods for mitigating the affect of hydrostatic pressure on the decellularization of porcine lungs. Specifically, the thesis details the design and construction of a vessel that rotates lungs during decellularization. This rotating vessel is evaluated in comparison to two other, non-rotation based, decellularization methods. The rotation device is found to more extensively decellularize the lung than either of the other two options. The thesis concludes by examining what other areas of work could be conducted in this field.

This thesis examines the challenges of decellularizing porcine lungs. The thesis identifies hydrostatic pressure and the role it plays in perfusate distribution within the lung as a potential roadblock for the decellularization of porcine lungs. The thesis examines methods for mitigating the affect of hydrostatic pressure on the decellularization of porcine lungs. Specifically, the thesis details the design and construction of a vessel that rotates lungs during decellularization. This rotating vessel is evaluated in comparison to two other, non-rotation based, decellularization methods. The rotation device is found to more extensively decellularize the lung than either of the other two options. The thesis concludes by examining what other areas of work could be conducted in this field.

Inflammatory Airway Disease has been reported in young racehorses worldwide. The aim of this study was to determine the prevalence of airway inflammation in an actively racing population of horses and to describe and quantify the degree of lung lesions in this population of horses. The Ontario Death Registry program provided a unique opportunity to evaluate the lungs of actively racing horses that died or were euthanized due to catastrophic injuries while racing or training. Lung sections of 95 horses were included in the study and evaluated using a previously validated histological airway scoring system. Additionally, staining with Toluidine blue and immunohistochemical labeling was performed on a subset of horses to further characterize the inflammation. Inflammatory cell infiltration, smooth muscle hyperplasia and hemosiderin were commonly found. The airway lesion scores were significantly higher in the caudal and dorsal sections of the lungs than in other areas. There was no correlation between the individual scores and either breed, sex, age, cause of death or performance index. The inflammatory and smooth muscle scores were normally distributed and the hemosiderin score was not. The inflammatory cell infiltration was composed of mononuclear cells, with increased number of mast cells and eosinophils in 3/20 and 12/95 horses respectively. Immunohistochemical labeling showed the inflammation around the airway to be composed of 41.0% CD3-positive T cells and 5.8% CD79a-positive B cells. In addition to the airway findings, inflammatory cell aggregates were observed around the pulmonary blood vessels and in the alveolar septa in 67/95 and 71/95 horses respectively. In conclusion, this study provides a histologic evaluation of a population of actively racing horses in which airway inflammation is a common finding.

No description available.

No description available.

Positive pressure mechanical ventilation (MV) has been utilised in the care of critically ill patients for over 50 years. MV essentially provides for oxygen delivery and carbon dioxide removal by the lungs in patient with respiratory failure or insufficiency from any cause. However, MV can be injurious to the lungs, particularly when high tidal pressures or volumes are used in the management of Acute Respiratory Distress Syndrome (ARDS) or similar acute lung injuries. The hallmark of ARDS is extensive alveolar collapse resulting in hypoxemia and carbon dioxide retention. Application of Positive End Expiratory Pressure (PEEP) is used to prevent derecruitment of alveolar units. Hence, there is a delicate trade-off between applied pressure and volume and benefit of lung recruitment. Current clinical practice lacks a practical method to easily determine the patient specific condition at the bedside without excessive extra tests and intervention. Hence, individual patient treatment is primarily a mixture of "one size- fits-all" protocols and/or the clinician's intuition and experience. A quasi-static, minimal model of lung mechanics is developed based on fundamental lung physiology and mechanics. The model consists of different components that represent a particular mechanism of the lung physiology, and the total lung mechanics are derived by combining them in a physiologically relevant and logical manner. Three system models are developed with varying levels of physiological detail and clinical practicality. The final system model is designed to be directly relevant in current ICU practice using readily available non-invasive data. The model is validated against a physiologically accurate mechanical simulator and clinical data, with both approaches producing clinically significant results. Initial validation using mechanical simulator data showed the model's versatility and ability to capture all physiologically relevant mechanics. Validation using clinical data showed its practicality as a clinical tool, its robustness to noise and/or unmodelled mechanics, and its ability to capture patient specific responses to change in therapy. The model's capability as a predictive clinical tool was assessed with an average prediction error of less than 9% and well within clinical significance. Furthermore, the system model identified parameters that directly indicate and track patient condition, as well as their responsiveness to the treatment, which is a unique and potentially valuable clinical result. Full clinical validation is required, however the model shows significant potential to be fully adopted as a part of standard ventilator treatment in critical care.

No description available.

Background Nanotechnology is an important and promising field that can lead to improved environment and human health and contribute to a better social and economic development. Materials in nanoscale have unique physiochemical properties which allow for completely new technical applications. Enlarged surface area and properties due to quantum physics are among the properties that distinguish the nanoscale. Nano safety has evolved as a discipline to evaluate the adverse health effects from engineered nanomaterials (ENMs). The prevalence of allergic diseases is increasing in the society. An additional issue is the influence of inherited factors on the health responses to ENMs. The aim of this thesis was to investigate the respiratory, inflammatory, and immunological effects following inhalation of ENMs; both sensitive and genetically susceptible individuals were used. Sensitive individuals refer to individuals with pre-existing respiratory diseases, such as allergic asthma, and genetically susceptible individuals refer to individuals prone to autoimmune and allergic diseases. Methods In vivo models of mice and rats were used. In study I the inflammatory and immune responses following exposure to titanium dioxide nanoparticles (TiO2 NPs) were investigated. The effect of when the TiO2 NP exposure occurs during the development of allergic airway inflammation was investigated in study II, with regards to respiratory, inflammatory, and immune responses. In study III, the influence of the genetics on the respiratory, inflammatory, and immune responses, following TiO2 NP exposure to naïve and sensitive rats was evaluated. In study IV, the inflammatory and immune responses of naïve mice and mice with an allergic airway inflammation were studied in lung fluid and lymph nodes draining the airways following inhalation to hematite NPs (α-Fe2O2). Results Exposure to TiO2 NPs induced a long-lasting lymphocytic response in the airways, indicating a persistent immune stimulation. The dose and timing of TiO2 NP exposure affected the airway response in mice with allergic airway disease. When the mice were exposed to particles and an allergen during the same period, a decline in general health was observed. By comparing different inbred rat strains it was demonstrated that genetically determined factors influence the immune and respiratory responses to TiO2 NP exposure in both naïve and sensitive individuals. Exposure to hematite NPs resulted in different cellular responses: naïve mice had increased numbers of cells while mice with allergic airway inflammation had decreased cell numbers in BALF. Analogous cell responses were also observed in the lung draining lymph nodes. Conclusion Altogether, this thesis emphasises the complexity of assessing health risks associated with nanoparticle exposure and the importance of including sensitive populations when evaluating adverse health effects of ENMs. / <p>Forskningsfinansiär: Umeå Center for Environmental Research, and by the Swedish Ministry of Defence</p>

This project assesses the four dimensional computed tomography (4DCT) capabilities of the Philips Brilliance Big Bore CT scanner (Philips Medical Systems, Cleveland, OH). A mechanical phantom imparts clinically relevant motions to acrylic spheres of various diameters. The size, shape, and position of these spheres, as measured with 4DCT, are compared to their true size, shape, and position. An evaluation of image quality is also performed. Maximum discrepancies between physical and imaged volumes, for all sphere sizes and motion ranges, did not exceed 2.6 mm (mean = 1.2 mm, standard deviation = 0.4 mm). For approximately tissue equivalent density objects, mean CT# in 4DCT images differed from those in standard clinical thoracic images by only a few Hounsfield units. Measured geometric precision along with the accuracy of mean CT#s observed in 4DCT phase images indicate that 4DCT is an appropriate imaging technique for treatment planning. / Medical Physics

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2006. / Härtill 3 uppsatser.