Nasal AEC cultures were established from children (0.6-14.9 years) undergoing elective surgical procedures under general anaesthetic, categorised as atopic asthmatics (n=12), virus-induced wheezers (n=8) or healthy controls (n=32) using questionnaire and serum IgE levels. All subjects were free of current respiratory symptoms. Successful AEC cultures were maintained to passage 2 or 41 (79%) subjects. AEC from children with a history of wheeze produced significantly less IL-8, IL-6, MCP-1 and G-CSF than AEC from healthy controls. When the wheezing phenotypes were considered separately, AEC from atopic asthmatic children released significantly less IL-8, IL-6, MCP-1 and G-CSF than AEC from controls but there were no significant differences between AEC mediator release from children with virus-induced wheeze and either atopic asthmatics or controls. Similar results were found for cytokine-stimulated AEC. In non-wheezy subjects, there were no differences in AEC mediator release between atopic and non-atopic individuals. There were no differences between the study groups in the percentage increments in mediator release in response to stimulation. In multivariate analysis, taking into account age, gender, passive smoke exposure, use of inhaled corticosteroids, total serum IgE and specific responses to inhaled aeroallergens as possible confounders, wheeze was the only significant predictor of AEC mediator release. It was concluded that there are intrinsic differences in AEC from children with a history of wheeze compared to healthy controls and these are independent of atopic status. This study provides further evidence that the airway epithelium is implicated in the pathogenesis of childhood wheezing. It is hypothesised that different systemic factors, such as atopy and viral responsiveness, interact with common epithelial abnormalities to give rise to different wheezing phenotypes. Further work is required to establish whether these abnormalities are primary or secondary and to confirm these findings in well-differentiated AEC cultured with an air-liquid interface.

M.Cur. / The South African Nursing Act (Act 50 of 1978) views the professional nurse as an independent practitioner, her independent function being the right to make decisions and taking the full responsibility for such liability. The professional nurse's liability depends on her authority, skills and responsibilities. Her role in the intensive care unit is aimed at optimal care of the ventilated patient, thus providing physical, psychological and spiritual well-being. The incidence of micro-organism colonization in the lower airway of the ventilated patient is researched in this study and nursing guide-lines are set out for the correct use of the ventilator. A contextual, descriptive study was carried out to: (a) determine the sterility of the humidifier reservoir and ventilator tubes; (b) determine which micro-organisms are present in the lower airways of patients after they have been ventilated; (c) set out guide-lines for the nursing staff on how to correctly use the ventilator. Sample analysis was done from the following: The sterile water in the reservoir prior to ventilation. Sputum obtained prior to extubation. Water from the reservoir after extubation (waterbasin of the humidifier). The water present in the ventilator tubes after extubation. The following conclusions were made: contamination is caused by the nursing staff; there was no migration of micro-organisms from the water reservoir to the circuit; the organisms in the ventilator circuit differed from those found in the lower airways of the patient...

A thesis submitted in fulflment of the requirements for the degree of Doctor of Philosophy in the School of Computer Science and Applied Mathematics. November 2015 / The understanding of uid ow at microscale geometrics is an increasingly important eld in applied science and mechanics, especially in bioinspiration and biomimetics. These elds seek to imitate processes and systems in biology to design improved e cient engineering devices. In this thesis, inspired by the e ciency of the insect tracheal system in transporting respiratory gases at microscale, mathematical models that both mimic and explain the gas exchange process are developed. Models for the simultaneous movement of respiratory gases across the insect spiracle, gas transfer from one respiratory chamber to the next, end di usion and tissue absorption at the tracheole tips, and tracheal uid transport are presented. Expressions for tracheal partial pressures of the respiratory gases, rate of change of gas concentrations, rate of tracheal volume change, spiracle behaviour on net gas ow, cellular respiration and tissue absorption, and global gas movement within the insect are presented as well. Two versions of bioinspired pumping mechanism that is neither peristaltic nor belongs to impedance mismatch class of pumping mechanism are then presented. A paradigm for se- lectively pumping and controlling gases at the microscale in a complex network of channels is presented. The study is inspired by the internal ow distributions of respiratory gases produced by rhythmic wall contractions in dung beetle tracheal networks. These networks have been shown to e ciently manage uid ow compared to current produced micro uidic devices. The insect-like pumping models presented are expected to function e ciently in the microscale ow regime in a simple or complex network of channels. Results show the ability to induce a unidi- rectional net ow by using an inelastic channel with at least two moving contractions. These results might help in explaining some of the physiological systems in insects and may help in fabricating novel e cient micro uidic devices. In this study, both theoretical and the Di erential Transform Method are used to solve the exible trachea with gas exchange problem as well as the 2D viscous ow transport with or without prescribed moving wall contractions problem. Both Lubrication theory and quasi- steady approximations at low Reynolds number are used in the derivation of theoretical analysis. ii Moreover, an analytical investigation into the compressible gas ow with slight rarefactions through the insect trachea and tracheoles is undertaken, and a complete set of asymptotic analytical solutions is presented. Then, estimation of the Reynolds and Mach numbers at the channel terminal ends where the tracheoles directly deliver the respiratory gases to the cells is obtained by comparing the magnitude of the di erent forces in the compressible gas ow. The 2D Navier-Stokes equations with a slip boundary condition are used to investigate the compressibility and rare ed e ects in the respiratory channels.

Thoracic loads (i.e., a heavy backpack) commonly used in occupational and recreational settings significantly challenge human physiological systems and increase the work of breathing, which may promote respiratory muscle fatigue and negatively impacts whole body performance during physical tasks. Accordingly this thesis: (Chapter number: II) designed a laboratory based protocol that closely reflects occupational demands and (III) assessed the effect that load carriage (LC) has upon physiological and respiratory muscle function. Consequently the thesis addressed (IV) acute, (V) chronic and (VI) functional inspiratory muscle loading strategies to assess the limitations and trainability of the respiratory muscles to load carriage performance. The novel laboratory protocol, performed wearing a 25 kg backpack load, combined submaximal load carriage (LC; 60 min treadmill march at 6.5 km·h-1) and self-paced time trial exercise (LCTT; 2.4 km) to better reflect the physiological demands of occupational performance (between trials mean difference -0.34 ± 0.89 min, coefficient of variation 10.5%). Following LC, maximal inspiratory muscle pressure (PImax) and maximal expiratory muscle pressure (P¬Emax) were reduced by 11% and 13% respectively (P<0.05), and further by 5% and 6%, respectively (P< 0.05), after LCTT. Acute inspiratory loading (2 × 30 forced inspiratory efforts 40% PImax) following an active warm-up (10 min lactate turnpoint) failed to improve LCTT despite a transient increase in PImax of ~7% (P<0.05). Chronic inspiratory loading (6 wk, 50% PImax, 30 breaths twice daily) increased PImax (31%, p<0.05) reduced HR and perceptual responses post-LC, and improved LCTT (8%, P< 0.05) with no change in a placebo control. Combining IMT with functional core muscle exercises improved PImax and LCTT by 7% and 4% respectively (P< 0.05), which was greater than traditional IMT alone. Acute, chronic and functional inspiratory muscle loading strategies did not protect against respiratory muscle or locomotor muscle fatigue during LC and LCTT.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / As infecÃÃes respiratÃrias agudas (IRA) sÃo importantes causas de morbidade e mortalidade em todo o mundo, acometendo principalmente crianÃas menores de cinco anos de idade. Essas infecÃÃes podem ser causadas por diferentes microrganismos, porÃm os vÃrus sÃo os mais frequentes. Esse estudo teve como objetivo descrever aspectos clÃnicos e epidemiolÃgicos de IRA de etiologia viral em crianÃas de zero a 12 anos de idade atendidas em serviÃo de emergÃncia de um hospital terciÃrio da cidade de Fortaleza-CE, no perÃodo de janeiro de 2007 a dezembro de 2008. Para tanto foram coletadas 1318 amostras de secreÃÃo de nasofaringe das crianÃas. As amostras foram submetidas à tÃcnica de imunofluorescÃncia indireta para detecÃÃo dos seguintes vÃrus respiratÃrios: vÃrus sincicial respiratÃrio (VSR), metapneumovÃrus humano (MPVh), adenovÃrus, influenza A e B e parainfluenza 1, 2 e 3. Os resultados desse estudo mostraram que pelo menos um vÃrus respiratÃrio foi detectado em 383 (29,1%) amostras. O vÃrus mais prevalente foi o VSR (44,4%), tendo o mesmo apresentado um padrÃo de sazonalidade definido, com associaÃÃo a estaÃÃo chuvosa. A co-infecÃÃo ocorreu em 12 (3,1%) amostras e o VSR foi o mais frequentemente associado. A mÃdia de idade dos pacientes foi de 23 meses e nÃo houve associaÃÃo entre o gÃnero desses pacientes e a positividade dos exames, apesar da maioria das crianÃas serem do sexo masculino. Entre os diagnÃsticos clÃnicos de etiologia viral, houve predomÃnio de infecÃÃo da via aÃrea superior (IVAS) (51,2%), e em relaÃÃo ao diagnÃstico especÃfico das infecÃÃes da via aÃrea inferior (IVAI), destacou-se a pneumonia. Portanto, os resultados desse estudo ressaltam a importÃncia dos vÃrus como causadores de IRA em crianÃas na cidade de Fortaleza, com as maiores taxas ocorrendo entre os meses de marÃo a junho, diferenciando-se da regiÃo Sul do paÃs, onde as maiores taxas sÃo encontradas nos meses de julho a outubro. / Acute respiratory infections (ARI) are important causes of morbidity and mortality worldwide, affecting mainly children under five years old. These infections can be caused by different organisms, but viruses are the most frequent. This study aimed to describe clinical and epidemiological aspects of viral ARI in children 0-12 years of age treated in the emergency department of a tertiary hospital in the city of Fortaleza, from January 2007 to December 2008. Therefore, we collected 1318 samples of nasopharyngeal secretions of children. The samples were subjected to indirect immunofluorescence for detection of the following respiratory viruses: respiratory syncytial virus (RSV), human metapneumovirus (hMPV), adenovirus, influenza A and B and parainfluenza 1, 2 and 3. The results of this study showed that at least one respiratory virus was detected in 383 (29.1%) samples. The most prevalent virus was RSV (44.4%), and presented the same seasonal pattern of a defined association with the rainy season. Co-infection occurred in 12 (3.1%) samples and RSV was the most frequently associated. The average age of patients was 23 months and there was no association between gender of these patients and positivity of the tests, although most children were male. Among the clinical diagnoses of viral etiology, there was predominance of upper respiratory infection diseases (URID) (51.2%), and in relation to the specific diagnosis of the lower respiratory infections diseases (LRID), stood out pneumonia. Therefore, the results of this study highlight the importance of viruses as causes of ARI in children in Fortaleza, with the highest rates occurring between the months March to June, differing from the southern region, where the highest rates are found in the months from July to October.

No description available.

No description available.

Thesis (Ph.D.) - University of Queensland, 2006. / Includes bibliography.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xi, 157 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 135-148).

published_or_final_version / Community Medicine / Master / Master of Public Health