Cilia are finger-like projections that extend from the surface of most cells. These microtubule-based structures serve important mechanical or sensory functions. Motile cilia have been implicated in fluid movement whereas the non-motile primary cilia have been shown to play a role in sensory signal transduction. There exists a dichotomy in the field that primary cilia have only sensory function and motile cilia only have mechanical function. The central question of this thesis project is "what are the structural and functional components of airway motile cilia and are these cilia sensory?" In Chapter 2, the role of Bardet-Biedl Syndrome (BBS) proteins in maintaining the structure and function of airway motile cilia is examined. We found that BBS proteins localize to the cilium and to ciliary-related structures in human airway epithelia. Using mutant mice we found that BBS proteins play an essential role in motile cilia structure and the loss of BBS proteins results in reduced ciliary beat. These proteins have previously been shown to play a role in primary cilia structure and function, and our studies indicate a novel function for BBS proteins. Chapter 3 examines the sensory role of motile cilia. Our data show that bitter taste receptors and components of the bitter taste signal transduction pathway localize to the motile cilia or to the ciliated cells. Ciliated cells also show an increase in intracellular calcium in response to bitter compounds, accompanied by a corresponding increase in cilia beat. The increase in intracellular calcium originates at the ciliated cells and is propagated to adjacent cells. Chapter 4 delves into the possibility that every motile ciliated cell also contains a single, primary cilium. Using immunostaining and Smoothened as a marker for primary cilia, we found that every group of motile cilia contains a single Smoothened-positive cilium. Furthermore, downstream components of the Sonic Hedgehog pathway are also present in ciliated cells. Chapter 6 is a summary chapter including possible explanations for observed outcomes and plans for future experiments. Our results indicate that the divide between primary and motile cilia may not be as great as has been previously thought.

Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by chronically poor airflow, which is the result of breakdown of lung tissue (known as emphysema) and small airways disease. It typically worsens over time. Most treatments are limited to the management of symptoms, which makes early detection more valuable to treat the disease etiology itself. With the advancement of computed tomography (CT), it is able to provide high resolution structural and functional imaging to distinguish the lung anatomic structures, as well as characterize their changes over time. Previously, the majority of CT-based measures have focused on quantifying the extent of airway and parenchymal damage. Recent studies suggests that pulmonary vascular dysfunction is an early lesion in COPD and associated with an emphysematous phenotype. Few studies attempted to quantify pulmonary vessel morphology and compared those measures across COPD groups. However, the scope of examined vascular structures in these studies was limited, majorly due to the lack of a standardized method to quantify a broad range of vascular structures. In this thesis, we propose to use anatomically defined airway branches as references to locate and morphologically quantify central pulmonary arteries in different lung regions. Although pulmonary vessel trees have complex topologic and geometric structures, airway tree possesses much simpler and consistent branching patterns and standardized anatomic nomenclatures are available up to sub-segmental levels. It is also well-known that airway and arterial branches have a unique pairing that is established by their spatial proximity and parallel configuration. Therefore, anatomically labeled airway tree provides a robust benchmark to locate consistent arterial segments for both intra- and inter-subjects. New methods have been developed for quantitative assessment of arterial morphology matched and standardized by associated airways at different anatomic branches. First, the skeletons of airway and vessel trees are generated to provide simple and hierarchical representations. Then, topologic and geometric properties of airways and arteries, such as distance, orientation and anatomic positon information, are explored to locate the target arterial segments. Finally, the morphologic properties, e.g. cross-sectional area, of target arterial segments are robustly computed. The developed methods in this thesis provides a standardized framework to assess and compare the vascular measurements in intra- and inter- subjects from a broad range of vessel branches in different lung regions. The work also serves as a practical tool for large longitudinal or cross-sectional studies to explore the pulmonary vessel roles played at the early stage of COPD. The major contribution of this thesis include: (1) developing two novel skeletonization methods that are applicable to airway and pulmonary vessel trees; (2) developing a semi-automatic method to locate and quantify central pulmonary arterial morphology associate to anatomic airway branches; (3) developing a fully automatic method to identify and reconstruct central pulmonary arterial segments associated to anatomic airway branches and quantify their morphology; (4) validating the methods using computerized phantoms, physical phantoms and human subjects; (5) applying the developed methods to two human lung disease studies.

Objective The goal of this project was to define and measure human volumetric airway dimensions with radiographic volumetric three-dimensional imaging and digital reconstruction of the pharynx using cone beam computed tomography to directly correlate these measurements with both normal and developmentally deficient jaw joints and their positions. The volume of the oropharynx was measured by creating a superior border connecting the 3-D midpoint of sella turcica and the posterior nasal spine and extending inferiorly to the level connecting the most infero-anterior point of C3 and the anterior hyoid bone as seen in the multi-planar views of the cone beam computed tomography image. The calculations were accomplished by using 3dMD software. Further extrapolation of this study'a data may be useful to establish the direct association of obstructive sleep apnea and deficiencies of jaw growth and airway development. Design In this retrospective study, 250 subjects were randomly selected from a pool of 800 referred for dental imaging at ddi Imaging Center in Sacramento, California. Digital images were captured using a low-radiation, rapid scanning cone beam computed tomography system (iCAT). Results A total of 250 subjects, 163 females and 87 males, were included in this study. Descriptive statistics were applied to the following variables: 1. Assessment of the relationship between total airway volume and several categorically independent variables: * For total airway volume, no significant difference was found between males and females; between the right temporomandibular positions; between right temporomandibular integrity; or between the left temporomandibular integrity. * There was a significant difference found between the left temporomandibular positions for total airway volume. 2. Assessment of the relationship between total airway volume and each cephalometric measurement: * Based on the Spearman correlation test, there were significant increasing relationships between total airway volume and several of the cephalometric measurements (p<0.05). * Correlation coefficients ranged from 0.13 to 0.22 indicating there were weak correlations between the two variables. 3. Assessment of the relationship between total airway volume and age: * Based on the Spearman correlation test, there was no significant relationship between total airway volume and age (p=0.8304). In addition, Spearman correlation showed no correlation between total airway volume and sex and skeletal growth pattern tendencies. Conclusions Three dimensional images of the airway offer the opportunity to serially examine individuals, acquire airway patency information, and improve the evaluation of sites of airway obstruction. Further studies to determine the effects of pharyngeal stenosis and other regional changes to the oropharynx upon physiologic response may be key to understanding the effects of biomechanical influences upon craniofacial form. Comprehension of structural inter-relationships will also help develop an understanding of how and why adaptive changes in airway shape and volume occur. Airway patency is related to many variables: head posture, the direction of mandibular rotation during growth and development, and hyoid bone position. Further studies may offer an increased understanding of these structural and positional interrelationships.

BACKGROUND: Older individuals suffer from higher rates of pulmonary infections than younger individuals. In addition, older individuals have increased morbidity and mortality due to pulmonary infections when compared to younger individuals. The physiological and immunological reasons for these aforementioned differences are not clear. Recently, non-invasive markers of the lung's physiologic and immunologic status have been recognized. This study employs one of these non-invasive markers, exhaled nitric oxide, in an attempt to determine how the airways may change with age, predisposing older individuals to pulmonary diseases and poorer outcomes as compared to younger individuals. METHODS: Exhaled nitric oxide measurements were obtained from a group of 25 older subjects (61 to 79 years old, median 72 years old) and a group of 23 younger subjects (21 to 30 years old, median 24 years old) that were non-smokers with no history of pulmonary disease, no recent respiratory infections, and no history of environmental allergies. A focused history and physical exam along with spirometry were used to confirm the normal pulmonary status of each subject. Exhaled nitric oxide was measured following the American Thoracic Society recommendations using the Sievers Nitric Oxide Analyzer 280i. The exhaled nitric oxide values for the old and young groups were compared using the Wilcoxon Rank Sum test. RESULTS: For the older subjects, the median exhaled NO concentration was 36.9 ppb. For the younger subjects, the median exhaled NO concentration was 18.7 ppb. These exhaled NO concentrations are significantly different (p = 0.0011). CONCLUSIONS: The exhaled NO concentrations are significantly higher in older individuals than in younger individuals. The reasons for this difference along with the significance are unclear and further studies will be necessary to further evaluate these issues.

In the reopening of fluid occluded airways, the pressure gradient due to the propagation of an air bubble causes extensive epithelial cell damage. The mechanism of cell necrosis and biotransport may be further understood by characterizing the flow fields near the tip of a semi-infinite bubble propagating through a fluid-filled bifurcation. A symmetric microfluidic pulmonary bifurcation model was fabricated for optical diagnostics with an instantaneous μ-PIV/ shadowgraphy microscopy system. Data handling and processing techniques were developed to calculate interfacial characteristics of multiphase flow from the microscopy system and accuracy was quantified through varying the apparatus set up. Differences in the interfacial geometric characteristics were quantified for changes in static and dynamic surface tension in comparisons of water, SDS, and Infasurf that may reflect changes in the mechanical stress that stimulate, and potentially damage, epithelial cells that line the airways. From these results, the asymmetrical tendencies of opening a symmetric pulmonary bifurcation model were quantified. It was found that pulmonary surfactant stabilized symmetric bifurcations that opened asymmetrically without the aid of surfactant. / acase@tulane.edu

Abstract not available

"May 2002." Bibliography: leaves 123-144. Aspects of the control of ventilation and an upper airway dilator muscle (genioglossus) are compared between healthy men and women, in an attempt to identify a gender difference that may contribute to the high male prevalence of sleep apnea.

Master of Science in Medicine / Rationale: Asthma management aims to achieve optimal control on the minimal effective dose of medication. We assessed the effectiveness of two algorithms to guide ICS dose in well-controlled patients on ICS+LABA in a double-blind study, comparing dose adjustment guided by exhaled nitric oxide (eNO) to clinical care algorithm(CCA) based on symptoms and lung function. Methods: We randomised non-smoking adult asthmatics on minimum FP dose 100μgs daily +LABA to ICS adjustment using eNO or CCA, assessed over 5 visits during 8 months treatment. Primary endpoints were asthma-free days and asthma related quality of life (QOL). Analysis was by mixed model regression and generalised estimating equations with log link. Results: 69 subjects were randomised (eNO:34, CCA:35) and 58 completed the study. At baseline mean FEV1 was 94% pred., mean eNO (200ml/sec) 7.1 ppb, median ACQ6 score 0.33. Median ICS dose was 500 μg (IQR 100-500) at baseline and 100 μg on both eNO (IQR 100-200) and CCA arms (IQR 100–100) at end of study. There were no significant differences between eNO and CCA groups in asthma-free days (RR=0.92, 95% CI 0.8–1.01), AQL (RRAQL<median = 0.95, 95% CI 0.8–1.1) or exacerbation-free days (HR = 1.03, 95%CI 0.6–1.7). Neither clinic FEV1 (overall mean difference FEV1 % pred. -0.24%, 95% CI -2.2–1.7) nor a.m. PEF (mean difference 1.94 L/min (95% CI -2.9–6.8) were significantly different. Similar proportions of subjects were treated for ≥1 exacerbation (eNO: 50%, 95% CI 32.1–67.9; CCA: 60%, 95% CI 43.9–76.2). Conclusion: Substantial reductions in ICS doses were achieved in well controlled asthmatics on ICS+LABA, with no significant differences in outcomes between eNO or clinically based algorithms.

Airflow and particle transport through the nasal cavity was studied using Computational Fluid Dynamics (CFD). A computational model of the human nasal cavity was reconstructed through CT scans. The process involved defining the airway outline through points in space that had to be fitted with a closed surface. The airflow was first simulated and detailed airflow structures such as local vortices, wall shear stresses, pressure drop and flow distribution were obtained. In terms of heat transfer the differences in the width of the airway especially in the frontal regions was found to be critical as the temperature difference was greatest and therefore heating of the air is expedited when the air is surrounded by the hotter walls. Understanding the effects of the airway geometry on the airflow patterns allows better predictions of particle transport through the airway. Inhalation of foreign particles is filtered by the nasal cilia to some degree as a defence mechanism of the airway. Particles such as asbestos fibres, pollen and diesel fumes can be considered as toxic and lead to health problems. These particles were introduced and the effects of particle morphology were considered by customising the particle trajectory equation. This mainly included the effects of the drag correlation and its shape factor. Local particle deposition sites, detailed deposition efficiencies and particle trajectories were obtained. High inertial particles tended to be filtered within the anterior regions of the cavity due to a change in direction of the airway as the air flow changes from vertical at the inlet to horizontal within the main nasal passage. Inhaled particles with pharmacological agents are often deliberately introduced into the nasal airway with a target delivery. The mucous lined airway that is highly vascular provides an avenue for drug delivery into the blood stream. An initial nasal spray experiment was performed to determine the parameters that were important for nasal spray drug delivery. The important parameters were determined to be the spray angle, initial particle velocity and particle swirl. It was found that particles were formed at a break-up length at a cone diameter greater than the spray nozzle diameter. The swirl fraction determined how much of the velocity magnitude went into a tangential component. By combining a swirling component along with a narrow spray into the main streamlines, greater penetration of larger particles into the nasal cavity may be possible. These parameters were then used as the boundary conditions for a parametric study into sprayed particle drug delivery within the CFD domain. The results were aimed to assist in the design of more efficient nasal sprays.

共著者あり。共著者名:Munakata Mitsuru, Sato Atsuko, Amishima Masaru, Homma Yukihiko, Kawakami Yoshikazu. / Hokkaido University (北海道大学) / 博士 / 医学