The purpose of this study was to examine the relationships between inflammation, infection and lung function in cystic fibrosis during the evolution of lung disease in childhood and early adolescence. The developmental stages of childhood and the progression of lung disease together affected the methods and techniques used in the study, with the consequence that the work for this thesis fell naturally into two parts. The first part concerned the study of early lung disease in infants and young children who were unable to expectorate or to cooperate with lung function testing. In the second part, the inflammatory processes in both stable lung disease and during clinical exacerbations in older children and adolescents were studied non-invasively using sputum. The absence of a recognised definition of pulmonary exacerbation lead to further investigation into clinical heterogeneity in the diagnosis and management of an exacerbation. In early lung disease, inflammation was not found to be independent of infection, with pathogens in the lower airways found to correlate with levels of inflammation, respiratory system compliance and degree of air trapping (a relationship not previously shown). This suggested that infection remains the key target to minimizing lung damage in cystic fibrosis. The relationship between sputum markers of inflammation and lung pathology in established disease was found to be less clear, with high inflammation levels in both stability and during exacerbation. Reduction in sputum inflammatory levels following treatment of an exacerbation was found to be greater in those with lower pre-treatment levels. The definition and management of an exacerbation was found to be an area lacking consensus among clinicians, with likely consequent heterogeneity of clinical care and therefore inhomogeneity of hospitalization as a surrogate measure of exacerbation in a research setting. The work from this thesis, and the ensuing publications, has contributed to the understanding of the interactions between the inflammatory and infectious processes involved in CF lungdisease, in both early and more established lung disease in childhood.

The grief experienced by mothers and fathers when their child is diagnosed with a life threatening chronic-illness was investigated in order to validate the presence of grief in these parents and look at the factors that influence it. More specifically, I was interested in whether the grief experience differed for mothers and fathers and the impact that perceptions and coping have on both these gender differences in grief and on grief in general. The particular population investigated in this study were parents of children with Cystic Fibrosis. Participants were recruited through questionnaires randomly sent out by the National Cystic Fibrosis Association. In all, 37 mothers and 15 fathers took part. Results not only confirmed presence of grief in these parents but also indicated that this grief differs for mothers and fathers, with mothers reporting significantly higher levels of physical distress. In line with the literature no gender differences were found in regards to perception of impact parents felt their child's chronic-illness had had on their lives. Contrary to what was expected, however, no differences were found amongst the coping strategies used by mothers and fathers. In regards to the question of which factors have the greatest impact on the grief experienced by mothers and fathers combined, the coping strategy of self-blame was found to be the most important, followed closely by negative perceptions. The significance of these findings and their implications for parents and the people who work with them was discussed.

Doctor of Philosophy / Cystic fibrosis (CF) is the most common inherited lethal disorder among Caucasian populations. Chronic pulmonary infections, particularly from Pseudomonas aeruginosa, are the major determinant of the morbidity and mortality of people with CF. It is generally accepted that people with CF acquire this pathogen independently from their surrounding environment, and that individual CF patients carry unique strains different from others. The spread of this pathogen from patient to patient is thought to be rare and occurs particularly among closely contacted cases such as CF siblings. However, over the past decade, there have been several reports of an emergence of clonal P. aeruginosa strains commonly found infecting a number of CF patients. One such report is from the CF paediatric clinic at the Royal Children’s Hospital in Melbourne in which more than half of the patients were infected with a single strain or clone, subsequently called Australian epidemic strain 1 or AES-1. A preliminary survey showed that AES-1 had spread extensively along the Australian eastern seaboard among CF patients attending other CF centres in Melbourne, Sydney and Brisbane, including adult patients at the Royal Prince Alfred Hospital (RPAH), Sydney. Another clonal strain, subsequently called AES-2, was identified in both CF adults and children at the Prince Charles Hospital and the Royal Children’s Hospital, in Brisbane. The total extent of prevalence of the AES-1 and AES-2 strains at the RPAH as well as the clinical status of patients who carried these strains was unknown. Moreover, the pathogenicity of these two clonal strains had not been investigated. The studies presented in this thesis investigated the prevalence of these clonal strains among CF patients attending the adult CF clinic at RPAH, Sydney by using pulsed-field gel electrophoresis. Overall, 50% of 112 patients with P. aeruginosa were found to be infected with clonal strains. The AES-1 and AES-2 strains were identified in 38% and 5% of the patients respectively. Two new clonal strains, called Sydney-1 and Sydney-2, were also identified. Patients with clonal strains had a significant increase in their number of exacerbations and hospitalisation days, and tended to have lower pulmonary functions when compared to patients infected with non-clonal strains. By using a variety of bioassays to examine the pathogenicity of the clonal and non-clonal strains, it was found that both AES-1 and AES-2 produced more virulence factors and were more resistant to antibiotics when compared to the non-clonal strains. AES-1 and AES-2 were associated with increased production of proteases, including elastase, alkaline protease and protease IV. Overall the results presented in this thesis suggest that there may be a link between virulence and transmissibility of this pathogen. The studies presented in this thesis also compared the biofilm forming capacities of the AES-1 and non-clonal isolates. AES-1 was shown to have greater biofilm-forming capacity than the non-clonal strains, when they were grown on a glass surface, suggesting a possible association between clonality and biofilm formation. A model for the study of bacteria grown in conditions similar to CF sputum was also developed. P. aeruginosa grown in this model was found to develop into clumps which may be comparable to the biofilm structure in the CF lung. This model was shown to be beneficial for transcriptomic and proteomic studies which are underway within the research group. AES-1 was also found to have phenotypic variations between isolates. By applying the amplified fragment length polymorphism technique, more subtypes of this clone were revealed. However, these detected subtypes did not correlate with the different phenotypes, suggesting minor mutations such as single point polymorphisms may be responsible for the phenotypic diversity within the clone. The final part of this thesis was devoted to examining the safety of a novel CF treatment: hypertonic saline (HS) inhalation. HS was shown to increase airway mucociliary clearance, while increased osmolarity associated with the use of HS was also shown to have an inhibitory effect on the formation of biofilms. Findings in this study proved that there was no evidence of strain selection in patients who received the long-term treatment with HS. The study also demonstrated that AES-1 was significantly more persistent in the CF lung than the non-clonal strains. The present thesis not only defines the clonal strains of P. aeruginosa and their implications for infected patients, but also provides a general understanding into the pathogenesis of both clonal and non-clonal strains infecting CF lungs.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 2003. / "16th September 2002." Accompanying CD contains 2 MPEG clips with accompanying text, and a copy in PDF format of: Recovery of airway cystic fibrosis transmembrane conductance regulator function in mice with cystic fibrosis after single-dose lentivirus-mediated gene transfer / M. Limberis ... [et al.], published in Human gene therapy vol. 13 (2002). Bibliography: leaves xxix-li.

Thesis (Ph.D.)--University of Tennessee Health Science Center, 2007. / Title from title page screen (viewed on July, 18, 2008). Research advisor: Anjaparavanda Naren, Ph.D. Document formatted into pages (xv, 72 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 66-72).

Thesis (Ph. D.)--University of Missouri--Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 178-187). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri--Columbia, 1999. / "May 1999." Typescript. Vita. Includes bibliographical references (leaves 178-187). Also available on the Internet.

Thesis (Ph.D.)--Virginia Commonwealth University, 2010. / Prepared for: Dept. of Clinical Laboratory Sciences. Title from title-page of electronic thesis. Bibliography: leaves 127-148.

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.