Thèses sur le sujet « Luns »

The generation of oxygen free radicals by the cytosolic enzyme, xanthine oxidase (XO), has been implicated in post-ischemic or reperfusion damage in several organs. XO catalyzes the conversion of hypoxanthine to urate with the concomitant production of superoxide anion free radical (0₂̅˙) and hydrogen peroxide (H₂O₂). Oxygen free radical-mediated injury has also been demonstrated in inflammatory lung disease. The possible involvement of XO in oxidative injury in the lung has not yet been studied. Therefore, this research project was designed to determine whether XO is present in the lung and to investigate its characteristics in porcine, bovine, rat and human lung and other tissues. Immunochemical analysis of xanthine oxidase in the tissues employed on polyclonal antibody raised to bovine milk XO. Proteins were separated by SDS-polyacrylamide gel electrophoresis of tissue homogenates. Proteins were transfered from the gels to nitrocellulose filters by Western blotting. After incubating the filters with a antisera containing the antibody to the purified bovine XO. XO on the filter was detected by its reaction with an enzyme-conjugated second antibody. XO was immunologically detectable in bovine lung and milk. Rat lung, kidney and liver all showed XO reactivity. XO was detectable in porcine liver but not detectable in porcine lung or kidney. Thus, the antibody to bovine XO was cross-reactive with porcine and rat XO. XO protein was not immunologically detectable in human lung possibly because the antibody was not cross reactive with the bovine antibody. In vivo, xanthine oxidase exists predominantly as a dehydrogenase rather than an oxidase. In this form as xanthine dehydrogenase (XDH) the enxyme does not produce either 0₂̅˙ or H₂O₂. The activity of both XDH and XO was measured in several tissues using a fluorometric assay which uses an artifical substrate, pterin which is catalytically converted to the fluorescent product isoxanthopterin (IXP). XO activity in porcine liver was of 1.1 x 10⁻³ µg IXP/mg protein/min although XO activity was not detectable in porcine lung and kidney, in rat lung of 1.7 x 10⁻² µg IXP/mg protein/min, rat kidney of 1.5 x 10⁻² µg IXP/mg protein/min, and rat liver of 2.2 x 10⁻² µg IXP/mg protein/min. Seven human lung biopsy samples were obtained after lung resection and initially tested for viability by determination of NADH oxidase activity and then assayed for XO-XDH. Three of these samples showed NADH oxidase activity indicating tissue viability, but only one of these three showed measurable XO activity of 5.35 x 10⁻⁶ µg IXP/mg protein/min. Irreversible conversion of XDH to XO is thought to be the result of limited proteolysis by a Ca²⁺/calmodulin activated protease, whereas reversible conversion of the enzyme occurs by oxidation of critical thiol groups. Studies on the rate and nature of fluorescence assay to detect catalytic activities of both enzyme forms. Incubation of lung homogenates with trypsin for 60 min caused irreverisble conversion of 90% of the XDH to XO. In contrast, incubation of homogenates at 15°C for 10 hours caused conversion of 100% of the XDH to XO. This conversion was reversible to the extent of 80% by reduction of thiol groups with dithiothreitol (DTT). The effects of free Ca²⁺ on the conversion of XDH to X0 was examined by using EDTA, a chelator of Ca²⁺ and other divalent cations; and EGTA, a more specific chelator of Ca²⁺. The presence of these chelating agents during homogenization of either normoxic or ischemic rat lung tissue did not inhibit reversible enzyme conversion. Increased XO activity was reversible by DTT. In the normoxic rat lung, homogenates prepared with EDTA and EGTA showed a similar conversion of 95% of XDH to XO which was reversible to 70% with DTT. In the ischemic rat lung, samples prepared with EDTA and EGTA showed a'conversion of 80% and 95% XDH to XO which was similar to control samples. The extent of reversibility to XDH was 75% with DTT incubation. In addition, perfusion of rat lungs with EDTA and DTT via a pulmonary artery cannula prior to 60 min of ischemia and homogenization did not affect the extent of XDH to XO conversion. These results indicate that irreversible Ca²⁺-mediated proteolytic conversion of XDH to XO does not occur to a great extent in the rat lung during either normoxia or ischemia. However, reversible conversion of XDH to XO does occur, suggesting that reversible thiol dependent conversion may play a role in the lung under both physiological and pathophysiological states.
Medicine, Faculty of
Pathology and Laboratory Medicine, Department of
Graduate

Infants with bronchopulmonary dysplasia (BPD), showed impaired body growth when compared to control infants. In terms of changes in the biochemical composition of the lung, BPD infants had higher DNA, soluble protein, collagen and desmosine contents as well as increased concentrations of DNA, collagen and desmosine in their lungs when compared to the growth patterns obtained for the lungs of control infants. Pathologically BPD was classified into 4 grades. Grade I BPD, was a phase of acute lung injury, grades II and III were proliferative phases. In grade IV BPD, lung structure returned towards normal. Evidence of fibrosis was seen by a significant increase in collagen concentration in grades II and III while desmosine concentration was seen to increase in grades III and IV suggesting that the increase in collagen and desmosine contents in the lungs of BPD infants may be controlled by two different mechanisms. Collagen type I/III ratio was seen to decrease progressively from grade II to grade IV BPD in comparison to age matched controls, indicating a higher proportion of type III collagen in the lungs of infants with BPD. From the clinical analysis and the results obtained from discriminant analysis procedure, it was seen that there was a high degree of correlation between the continuation of the disease and collagen accumulation in the lungs suggesting that pulmonary fibrosis with excessive collagen accumulation is an integral part of BPD. This fibrotic process seemed to correlate significantly with assisted ventilation and high oxygen supplementation received by the infants, but it was difficult to assess the individual contribution of the two treatments in the pathogenesis of BPD. Other variables such as severity of the initial disease and the length of survival of the infants, made the assessment of individual contribution much more difficult.
Medicine, Faculty of
Pathology and Laboratory Medicine, Department of
Graduate

Introduction: CF (cystic fibrosis) and PCD (primary ciliary dyskinesia) are obstructive airway diseases characterised by frequent infections and neutrophilic inflammation. However, PCD has a much milder course than CF. Pilot data showed that in PCD (n=8) the relationship between LCI (lung clearance index) derived from multiple breath washout (MBW), and FEV1 (forced expiratory volume in 1 second) differed from the established correlation in CF. This thesis sought to identify the reasons. Materials and Methods: Larger PCD (n=38) and CF cohorts (n=125), a non-CF bronchiectasis comparator group (n=28), and healthy controls (n=44) were recruited. All performed LCI and spirometry, and subgroups had more complex MBW parameters (conventional and modified phase III analysis and curvilinearity) calculated and HRCT scans scored. Results: As in the pilot data, there was no relationship between LCI and FEV1 in PCD, unlike in CF. PCD patients had fewer structural abnormalities than CF despite similar or worse spirometry and LCI, and the relationship between HRCT and spirometry or LCI in PCD was again different from that seen in CF. MBW analyses showed that Scond* is near-normal in PCD, suggesting less flow asynchrony, compared with CF. Conclusions: There are differences in the nature of distal airway disease between PCD and CF. As the non-CF bronchiectasis patients were similar to CF (rather than PCD), this likely results from the primary mucociliary clearance defect in PCD compared with secondary impairment in the other two conditions. This may be important as care of PCD patients is extrapolated from that of CF patients, which may not be appropriate. It is important not to extrapolate outcome measures uncritically between different disease groups, both clinically and when planning randomised controlled trials. Finally, a better understanding of what causes the better prognosis in PCD may help identify future new treatment avenues in CF.

This study examined the effects of epinephrine, norepinephrine, AVP and ACh on fluid movement by the lungs of the late-term guinea pig fetus. Catecholamines and AVP are secreted in high amounts by the fetus during delivery, and could be important with respect to fetal lung fluid removal; this event is vital at the time of birth. The lungs were supported in vitro for a duration of three hours, and production rates were measured using a dye-dilution technique. The average resting production rate in terms of ml/kg‧h declined with gestational age (54-67 days gestation; n=171). There was a lesser decline in the average resting production rate in terms of ml/h. The average production rate of untreated preparations in the first hour was 1.60 ± 0.26 ml/kg body weight per hour, and rates did not change significantly during the remaining two hours of experimentation (n=30). This rate is comparable to those reported from chronically catheterized fetal sheep. Treatment was administered during the second hour of experimentation, following an ABA design. Lungs (n=36) were transferred to fresh Krebs-Henseleit saline containing one of the following concentrations of epinephrine: (a) 10‾⁵ M; (b) 10‾⁶ M; (c) 10‾⁷ M; (d) 5 x 10‾⁸ M; (e) 10‾⁸ M; and (f) 10‾⁹ M. With the exception of the top dose, epinephrine treatment caused an immediate reduction in fluid secretion, or fluid reabsorption. Sodium followed the movement of water in all cases. The effect of epinephrine at 10‾⁷ M was maximal, and the threshold dose for epinephrine was calculated at 1.78 x 10‾¹¹ M. Phentolamine and propranolol had no effect in control preparations. However, phentolamine completely blocked the effect of epinephrine, whereas propranolol was ineffective. Isoproterenol had no effect on pulmonary fluid production. Alpha-adrenergic receptors apparently mediate the effect of epinephrine on pulmonary fluid movement in the fetal guinea pig lung. This conclusion is different from that obtained in fetal sheep, in which beta-adrenergic receptors are utilized. A possible synergism between epinephrine and AVP was examined. Lungs (n=12) were transferred to fresh Krebs-Henseleit saline containing either (a) 0.6 mU/ml AVP, or b) 0.6 mU/ml AVP combined with epinephrine at 10‾⁷ M. Treatment with AVP caused a slow, prolonged reduction in fluid production. Treatment with AVP together with epinephrine did not demonstrate synergism. The effect of norepinephrine (NE) was examined. Lungs (n=36) were transferred to fresh Krebs-Henseleit saline containing one of the following concentrations of NE: (a) 1.24 x 10‾⁵ M; (b) 1.24 x 10‾⁶ M; (c) 1.24 x 10‾⁷ M; (d) 5.24 x 10‾⁸ M; (e) 1.24 x 10‾⁸ M; and (f) 1.24 x 10‾⁹ M. In all preparations, treatment with NE resulted in an immediate reduction in fluid production, and reabsorptions were observed at the higher doses. Sodium followed the movement of water in every case. The threshold dose was calculated at 3.16 x 10‾¹⁰ M. Phentolamine blocked the effect of NE, reinforcing the importance of pulmonary alpha-adrenergic receptors in the fetal guinea pig. There was no relationship between age and degree of response with treatment of either epinephrine or NE, but fetuses under 78.0 g did not respond to NE. The effect of ACh was examined. Lungs (n=24) were transferred to fresh Krebs-Henseleit saline containing one of the following concentrations of ACh: (a) 10‾⁴ M; (b) 10‾⁵ M; (c) 10‾⁶ M; and (d) 10‾⁸ M. At the three top doses, immediate and powerful reabsorptions of pulmonary fluid were observed in older fetuses (60 days gestation and above); significant falls were observed in the younger fetuses. This result was unexpected, as it was hypothesized that ACh would stimulate fluid production. The threshold dose for ACh was between 10‾⁶ M and 10‾⁸ M. Phentolamine blocked the effect of ACh. This result suggested that reabsorption is a result of an indirect effect of ACh acting through pulmonary alpha receptors. The results in this study show that epinephrine, NE, AVP and ACh are all important promoters of fetal pulmonary fluid removal in the fetal guinea pig. Pulmonary alpha-adrenergic receptors mediate the effects of epinephrine, NE and ACh (indirectly). The conclusions drawn from this study emphasize the importance of species' comparison in fetal research. LIST OF ABBREVIATIONS AVP Arginine Vasopressin NE Norepinephrine DOPA dihydroxyphenylalanine PNMT Phenylethanolamine n-methyltransferase ACh Acetylcholine
Science, Faculty of
Zoology, Department of
Graduate

This study was designed to gain an understanding of the family experience when an adult member has chronic obstructive pulmonary disease (COPD). It is recognized that illness within the family affects the well-being of the family unit and the health of all members. To understand the impact of COPD upon the family, however, the literature provides only knowledge of the experience of the individual who has COPD and the spouse, not that of the family unit. Thus, the purpose of this study was to describe and explain the COPD experience from the perspective of the family unit. A qualitative method, phenomenology, was chosen for this investigation. Data were collected through semi-structured interviews with eight families who shared their experiences. From the content analysis of these data, three themes that were common throughout the families' accounts were identified and developed to describe and explain family life with COPD. The first theme, disease-dictated family life, describes four aspects of a common lifestyle that is imposed on the family by the characteristics of COPD. The second theme, isolation, describes the isolation that accompanies the illness experience, for the family group and the individual members within the group. The final theme, family work, describes the four primary challenges the families face and the coping strategies they use to deal with them. These findings revealed that COPD acts as an intense stressor within the family, requiring extensive family work to cope with COPD in a way that maintains the well-being of the family unit. Furthermore, it was found that living with COPD in many ways inhibits the resources within the family and those external sources of support that foster the family's ability to manage the stress associated with living with COPD. The implications for nursing practice and nursing research were delineated in light of the research findings.
Applied Science, Faculty of
Nursing, School of
Graduate

The aim of this thesis is a data transfer protocol implementation for a mobile control unit for transporting lungs. Apart from this thesis the data transfer protocol is used in AlveoPic project. The introductory part is focused on an anatomical and physiological background of a human respiratory system. Consequently it describes the i-Lung module and the mobile circulation module (MCM). It deals with the healthcare informatics interoperability standards with an emphasis to the ISO/IEEE 11073 standard. The subsequent part is represented by MCM’s simulator realization and design of a monitoring application. The final part aims at an analysis of the test cases for a monitoring application’s and a protocol framework’s control.

Dissertation (PhD)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: Background to the study OLA can give rise to certain problems: 1. A significant decrease in lung volume is reported to occur in the dependent lung during OLA in the LDP. This decrease in lung volume can result in an acute increase in opposition to RV ejection. The potential problem is that the right ventricle is a thin walled structure that can generate considerably less work than the thicker walled LV. It possesses little reserve to deal with an acute rise in afterload as may occur during acute lung injury or after lung resection. Therefore, this increase in afterload during OLA may potentially impair RV-PA coupling. Albeit this potential problem exists, the changes in RV afterload and how the right ventricle performs during OLA have not been well studied. 2. Arterial hypoxemia, due mainly to venous blood being shunted via the non-ventilated lung, may present a clinical problem during one lung ventilation. a. The relative resistances of the pulmonary vascular beds of the dependent ventilated and nondependent non-ventilated lungs are an important factor governing shunting and thus arterial oxygenation during one lung anesthesia. A high non-ventilated lung PVR and low ventilated lung PVR will facilitate good arterial oxygenation during OLA. An increase in non-ventilated lung PVR is governed predominantly by hypoxic pulmonary vasoconstriction. A low opposition to pulmonary blood flow in the dependent lung is facilitated predominantly by a high alveolar oxygen tension and normal lung volume, albeit other factors also play a role in this regard. b. The saturation and oxygen content of mixed venous blood will contribute significantly to the arterial oxygenation in the presence of a large shunt as occurs during OLA. i. On the one hand, venous desaturation as a cause of hypoxemia during one lung anesthesia has not as yet been systematically addressed in the literature. ii. On the other hand, if RV afterload increases to such a degree that it leads poor RV performance, this may cause impairment of global circulatory efficiency and lead to mixed venous desaturation. The question that has been raised is whether inotrope infusions could improve RV and LV performance, cardiac output, and thereby the efficiency of the circulation. Increases in the efficiency of the circulation will result in an improvement in mixed venous and arterial oxygenation in the presence of a large shunt. Nonetheless, the administration of inotrope infusions in the presence of a shunt and during OLA has been reported to aggravate hypoxemia. Thus at the time of conducting the study, conflicting reports of whether increasing cardiac output and thereby mixed venous oxygenation would increase or decrease arterial oxygenation during OLA In the light of the above, the researcher thus investigated RV afterload, RV performance and coupling to its load during OLA. The study also addressed the question whether different levels of inotrope infusion or PEEP hadbeneficial or deleterious effects on RV afterload, RV performance and coupling to its load during OLA. Furthermore, if cardiac output increased during OLA secondary to the infusion of inotropes, would this improve the efficiency of the circulation, mixed venous oxygenation and thus the arterial oxygenation during OLA, or would it worsen shunt and arterial oxygenation during OLA? Control group: OLA and the opposition to pulmonary flow Pulmonary arterial elastance increased by between 18 to 36% during OLA and mean PAP rose by 32% after initiation of OLA This increase in mean PAP on initiation of OLA is greater than that observed by certain investigators but similar to that seen previously in patients with damaged lungs. The question arose as to why pulmonary artery pressure rises during OLA? From consideration of Ohm’s law, pressure may be regarded as the product of flow and resistance (Mark, Slaughter et al. 2000). The increase in mean PAP during OLA is due to two reasons. 1. Firstly, the pressure versus flow curve is likely to be steeper during OLA. This is because pulmonary vascular recruitment and dilatation (pulmonary vascular reserve) is more limited in scope in these patients than is usual and most likely accounts for the increase in pulmonary artery pressure during OLA. The reasons for the limited pulmonary vascular reserve in the DL during OLA include: a. The pulmonary vascular bed of patients subjected to OLA is frequently abnormal because of its underlying pathology, b. During OLA in the lateral decubitus position, lung volume decreases to a greater degree than during two-lung anesthesia (Klingstedt, Hedenstierna et al. 1990). c. This decrease in lung volume will be further aggravated by DLT malpositions, secretions and blood, and absorption atelectasis due to the use of high concentrations of oxygen (Hedenstierna 1998; Krucylak, Naunheim et al. 1996). d. Excessive amounts of extrinsic or intrinsic PEEP during OLA can compress the intra-alveolar capillaries and deleteriously affect the pulmonary vascular resistance (Ducros, Moutafis et al. 1999; Inomata, Nishikawa et al. 1997; Bardoczky, Yernault et al. 1996; Yokota, Toriumi et al. 1996). 2. Secondly, there is greater flow through this vascular bed that possesses a higher resistance. It is noteworthy that the increase in mean PAP did not exceed a value of 25 mm Hg during OLA, even though cardiac output increased by 30%. However, in studies conducted in patients with “damaged lungs”, greater increases in PA pressure (accompanied by a decrease in RVEF) have been reported to occur on PA ligation. A question arises as to why differences exist between PA clamping and OLA? The answer may well be that the observed plateau in the rise of PA pressure during OLA is as a result of progressive diversion of flow to the NDL as PA pressure rises. Support for such a suggestion comes from the observation that concomitant with increases in PA pressure during OLA, HPV is progressively inhibited and shunt fraction progressively rises. This increase in shunt fraction that has been observed to occur as PA pressure rises, reflects an increase in diversion of pulmonary blood flow to the NDL. The impact of diversion of this blood to the NDL is that it possibly acts as a safety mechanism limiting increases in PA pressure and other indices of opposition to pulmonary flow during OLA. This “blow-off effect” will protect the RV until PA clamping occurs.Control group: OLA and RV function The current study represented the opportunity to investigate the significance of the abovementioned increases in PA pressures and elastance on RV performance during OLA. The current study indicates that at the moderate (30%) increases in PAP that accompanied the initiation of OLA, RV performance, as judged by stroke volume, cardiac index, RVEF and RVSWI, did not deteriorate compared to the baseline awake status. In fact, cardiac output increased following surgical incision: this was probably due to sympathetic nervous system stimulation. This observation also fits in with other studies in which RV performance usually only begins to deteriorate when indices of opposition to RV ejection reach 200 to 250% of baseline. Furthermore, a constant preload, as indicated by unchanged central venous and pulmonary artery wedge pressures, and right ventricular end-diastolic volumes were observed throughout the study period. In other words, this increase in RV afyterlad did not cuse the RV to dilate durign OLA. The relationship between stroke work and afterload will vary, depending on the contractile reserve of the ventricle. In this regard, it could be concluded that under the conditions operative in the current study, the RV was operating on the upslope of the RVSWI versus Ea relationship. This supports the observation that RV function is well preserved during OLA. In conclusion, regarding the indices of opposition to pulmonary flow and RV performance during OLA, it can be concluded that: 1. Opposition to RV ejection increases. This is evidenced by a 30% rise in mean PAP and 18 to 36% increase in pulmonary arterial elastance. 2. Right ventricular performance as indicated by RVSWI, RVEF and stroke volume does not decrease during OLA compared with when the patients awake or subjected to two-lung anesthesia. 3. Furthermore, coupling between the RV and its load is well preserved during OLA. This would imply that the RV operates at close to maximal efficiency during OLA and that RV stroke work reserve is present during OLA. It is likely that the RV, which continues operating as a flow pump as it does in normal life, easily copes with the small increases in RV afterload during OLA. Dobutamine during OLA: opposition to pulmonary flow and RV performance The effects of dobutamine infusions on RV performance during OLA can be summarised as follows: 1. Low rates of dobutamine infusion (3 ug.kg-1.min-1) increased cardiac output, stroke volume, and RVSWI. The administration of dobutamine 3 ug.kg-1.min-1 was not accompanied by increases in RV afterload. Therefore, low infusion rates of dobutamine did benefit RV-PA coupling during OLA. 2. However, administration of higher dosages of dobutamine (5 and 7 ug.kg-1.min-1) during OLA was associated with increases in certain indices of opposition to pulmonary blood flow. For example, PA elastance, mean PA pressure, and PVR increased by 30% to 40% compared to both when the patients were awake and when both lungs were being ventilated. Furthermore, PA compliance decreased by up to 61% when dobutamine 5 and 7 ug.kg-1.min-1 were infused compared to the OLA step when dobutaminewas not administered. The increases in mean PAP and PVR are considered to be of limited clinical significance. However, the decrease in PA compliance during the infusion of the highest dosage of dobutamine is clinically significant. PA compliance represents one of the factors determining vascular impedance in the Windkessel model of the circulation. The increases in opposition to pulmonary flow and lack of progressive increase in indices of RV performance are in contrast to what is expected to occur on administration of increasing dosages of the inotrope and pulmonary vasodilator, dobutamine. The reasons for the increase in opposition to pulmonary flow include exhaustion of the pulmonary vascular reserve during OLA at the high cardiac indices of 5 to 5.5 l.min-1.m-2. This aspect overshadowed the expected pulmonary vasodilator effects of dobutamine. Moreover, it is probable that the increase in RV afterload was significant enough to prevent right ventricular performance increasing as would be expected with the administration of progressively higher dosages of inotrope. While dobutamine was being administered during OLA, mean PAP increased to a maximum of 24.9 ± 6.2 mm Hg at a cardiac index of 5.5 ± 1.2 l.min-1.m-2. However during OLA, in the control group, mean PAP was 24.0 ± 7.7 mm Hg at the maximum cardiac index of 4.4 ± 1.1 l.min-1.m-2. This represented a relatively limited rise in PA pressure compared with administration of dobutamine alone. The most likely reason why there may have been a limited increase in mean PAP while dobutamine was being administered is that the “blow off” effect of the NDL vasculature limited the rise in PA pressure. Oxygenation during OLA With regard to oxygen flux, venous and arterial oxygenation during OLA in the control group, the following was observed: 1. Induction of anesthesia and the approximately 1O Celsius decrease in temperature induced an approximately 40% decrease in VO2 that continued during OLA. 2. Initiation of OLA resulted in an increase in cardiac output compared to baseline OLA and awake states. 3. The consequence was an increase in S􀀀��������O2 from 75% and P􀀀��������O2 from 5.4 kPa when the patients were awake to a P􀀀��������O2 of 9.0 ± 1.7 kPa and S􀀀��������O2 of 90.6 ± 4.7% during one-lung anesthesia. 4. During OLA, the significant increase in venous oxygenation resulted in an increase in arterial oxygenation compared to the awake state in spite of the approximately 37% shunt occuring during OLA. 5. Under conditions in the present study, dobutamine administration during OLA did not improve, but maintained the already high venous and arterial oxygenation compared with OLA alone. Therefore, the study hypothesis, that dobutamine would induce improvement in RVF and the increase in cardiac output during OLA would improve arterial oxygenation, does not hold in the current study. The hypothesis that dobutamine administration and improving cardiac output during OLA would increase arterial oxygenation was therefore rejected. However, the rejection of the hypothesis means that the findings of the current study are in contrast to the findings of Mathru et al, and Nomoto and Kawamura. These authors demonstrated that inotrope administration resulted in an increase in arterial oxygenation. Nonetheless, the different results are not at odds with each other. In fact, these differences help to clarify the effect of increases in cardiac output on arterial oxygenation in the presence of asignificant shunt. The differences between the studies can be explained in the following way. Conditions in the current study resulted in a favourable DO2/VO2 ratio and a high starting P􀀀��������O2 even before dobutamine administration was commenced. Therefore the venous saturations were on the flat part of the oxygen dissociation curve and also on the flat part of the relationship between cardiac output and arterial oxygen content originally described by Kelman, Nunn and colleagues. Further increases in cardiac output and the DO2/VO2 ratio would not be expected to, and did not, increase P􀀀��������O2, S􀀀��������O2, or C􀀀��������O2. Thus, arterial oxygenation content and saturation did not change subsequent to the increase in cardiac output associated with the administration of dobutamine in the current study. In contrast, in the Mathru study, the low starting venous saturations and tensions were improved by increases in the DO2/VO2 ratio. As the starting venous saturation was “low,” significant benefit in arterial oxygenation was obtained on increasing cardiac output in that study. One significant concern for the clinician regarding the administration of the inotrope dobutamine during OLA is that it may increase shunt fraction (Qs/Qt) and thereby decrease arterial oxygenation during one lung ventilation. The influence of dobutamine on arterial oxygenation during OLA may theoretically be related to the balance of the following divergent effects: 1. By improving the relationship between oxygen delivery and consumption, dobutamine increases P􀀀��������O2. This increase will benefit arterial oxygenation in the presence of a large shunt, 2. The above has to be weighed against possible increases in VO2 induced by dobutamine, the consequence of which will be a decrease in P􀀀��������O2. Such increases in VO2 were not seen on administration of dobutamine in the current study, 3. An increase in PA pressure accompanying the increased cardiac output will oppose HPV and increase shunt in both the dependent and non-dependent lungs, 4. Direct inhibition of HPV by dobutamine and, 5. The influence of P􀀀��������O2 on HPV (i.e. high levels of venous oxygenation will inhibit whereas low levels will potentiate HPV). Nonetheless, in spite of the concerns (risk) of hypoxemia on administering dobutamine during OLA, dobutamine administration did not decrease PaO2 or arterial oxygen saturation, and neither did it increase the cost of oxygenation compared to when OLA was conducted in the absence of dobutamine infusions. In addition, the findings of studies conducted by Mathru and colleagues, Nomoto and Kawamura and the current study indicate that under usual clinical conditions present during OLA in the LDP, the administration of low dosages of dobutamine do not increase shunt fraction. In fact, the beneficial effect of the increase in cardiac output on venous oxygenation resulted in an increase in arterial oxygenation in the study by Mathru and colleagues; similar mechanisms were most likely operative in the study conducted by Nomoto and Kawamura. Therefore, there is currently no evidence that the administration of dobutamine in dosages of up to 7 ug.kg-1.min-1 increases shunt and worsens arterial oxygenation in humans subjected to OLA in the LDP. It is apparent that the vasodilatory effects of dobutamine resulting in a possible increase in shunt fraction (Qs/Qt) is therefore not the only factor to consider when studying its effects on arterial oxygenation. What is also of great relevance whenconsidering the effects of an inotrope on arterial oxygenation is the effect of inotropic drugs on the venous oxygen content. It is possible that Qs/Qt could be increased by the administration of inotrope. Nonetheless, if venous oxygenation is favourably affected by the administration of dobutamine, then a depressant effect on arterial oxygenation by an increase in the amount of blood passing via the shunt may be negated. If the increase in venous oxygenation is very significant, there may even be benefits in terms of arterial oxygenation, as was the case in the current study. This approach to how the quality of the blood passing via the shunt affects arterial oxygenation shifts the emphasis on prevention and treatment of hypoxemia during OLA from the lung to the efficacy of the circulation. In other words, the emphasis is shifted from what predominantly happens to the non-ventilated lung (HPV) to primarily the efficacy of oxygen flux during OLA. Extrinsic and intrinsic PEEP and OLA The effects of PEEP on hemodynamics and oxygenation observed during OLA in the current study may be summarised as follows. When PEEP5 was applied to the DL during OLA in the current study: 1. Neither right ventricular function, hemodynamics, oxygen flux nor arterial oxygenation was affected by the application of PEEP5 compared to the step when no external PEEP was applied. 2. Significant amounts of intrinsic PEEP were present during OLA in the control group patients. The degree of intrinsic PEEP was weakly related to the degree of obstructive airways disease present on preoperative LFT’s. 3. The most likely reason why PEEP5 did not make a difference to oxygenation or hemodynamics was the existence of similar amounts of intrinsic PEEP during OLA. These findings confirm Myles’s contention that low levels of intrinsic PEEP may have salutary effects on oxygenation during OLA. When PEEP10 was applied to the DL during OLA in the current study, it led to a decrease in stroke volume. This decrease is predominantly due to a decrease in preload, as PVR does not increase to levels that are known to impair RV performance. The decrease in the DO2/VO2 ratio that was induced by PEEP10 predictably decreases P􀀀��������O2 and can potentially lead to impairment of arterial oxygenation. It can therefore be concluded that greater (excessive) amounts of PEEP under more unfavourable circulatory conditions than were observed in the current study, may have deleterious cardio-respiratory effects. In summary, optimising DL volume plays an important role in determining arterial oxygenation. However, the therapeutic index for PEEP is narrow and the anesthesiologist needs to know firstly when the lung volume of the DL approaches FRC and secondly, how to avoid dynamic hyperinflation of that lung. One significant problem is that the best method of monitoring FRC during OLA is not clear at present.
AFRIKAANSE OPSOMMING: Agtergrond tot die studie Eenlongnarkose mag tot sekere probleme aanleiding gee. ’n Betekenisvolle afname in volume van die onderlong vind in die laterale decubitus posisie tydens eenlongnarkose plaas. Hierdie afname in longvolume mag egter ’n akute verhoging in regter ventrikulêre nalading tot stand bring. Die probleem is egter dat die regter ventrikel ’n dunwandige struktuur is wat potensieel baie minder werk as die dikwandige linker ventrikel kan genereer. Die regter ventrikel het min reserwe om ’n akute verhoging in nalading te weerstaan soos wat gebeur met akute longbesering of na longreseksie. Dus die verhoging in nalading wat gepaard gaan met eenlongnarkose mag die koppeling tussen die regter ventrikel en die pulmonale arterie belemmer. Alhoewel hierdie potensiële probleem bestaan, is die verandering albei in regter ventrikulêre nalading en hoe die regter ventrikel funksioneer tydens eenlongnarkose nog nie goed bestudeer nie. 1. Arteriële hipoksemie, hoofsaaklik te wyte aan die groot aftakking via die long wat nie geventileer word nie, mag kliniese probleme tydens eenlongnarkose teweegbring. 2. Die weerstand wat die pulmonale vaskulêre beddens van die geventileerde en nie-geventileerde longe bied teen bloedvloei is belangrike faktore wat aftakking en dus arteriële oksigenasie tydens eenlongnarkose beheer. ’n Hoë weerstand van die nie-geventileerde long en ’n lae weerstand van die geventileerde long se pulmonale vaskulêre beddens sal bevredigende arteriële oksigenasie tydens eenlongnarkose fasiliteer. ’n Verhoging in die pulmonale vaskulêre weerstand van die nie-geventileerde long is hoofsaaklik te wyte aan hipoksiese pulmonale vasokonstriksie. ’n Lae pulmonale vaskulêre weerstand in die geventileerde onderlong is hoofsaaklik gefasiliteer deur ’n hoë alveolêre suurstofspanning en ’n normale long volume, alhoewel alle faktore ook ’n rol in hierdie verband speel. 3. In die teenwoordigheid van die groot aftakking wat bestaan tydens eenlongnarkose, sal die saturasie en suurstof inhoud van gemeng veneuse bloed ’n betekenisvolle bydrae aan arteriële oksigenasie maak. a. Veneuse saturasie as ’n oorsaak van hipoksemie tydens eenlongnarkose, is nog nie sistematies in die literatuur ondersoek nie. b. Indien regter ventrikulêre nalading tot so ’n mate verhoog dat dit tot swak ventrikulêre uitwerp lei, mag dit ’n oorsaak wees van ontoereikendheid van die globale bloedsomloop en tot gemeng veneuse desaturasie lei. Die vraag is dus of verhoging van die kardiale omset deur inotrope ondersteuning die toereikendheid van die sirkulasie kan verbeter. Verbeterde sirkulasie toereikendheid sal tot ’n verhoging in gemeng veneuse en arteriële oksigenasie lei in die teenwoordigheid van ’n groot aftakking. Nietemin, die toediening van inotrope in die teenwoordigheid van ’n groot aftakking tydens eenlongnarkose gerapporteer om hipoksemie te vererger tydens eenlongnarkose. Dus ten tye van die uitvoer van dié studie, is daar uitdrukking gegee tot teenstrydige opinies in die literatuur oftewel verhoging in kardiale omset arteriële oksigenasie sal verbeter of versleg tydens eenlongnarkose.In die lig van die agtergrond hierbo, het die navorser dus regter ventrikulêre nalading, regter ventrikulêre funksie en koppeling van die regter ventrikel met sy lading tydens eenlongnarkose ondersoek. Die studie het ook die vraag benader of inotroop infusies of PEEP goeie of slegte gevolge sou hê op regter ventrikulêre nalading, regter ventrikulêre funksie en koppeling van die regter ventrikel aan sy lading tydens eenlongnarkose. Sou die kardiale omset en die toereikendheid van die sirkulasie sou verbeter sekondêr tot die toediening van inotrope tydens eenlongnarkose, gemeng veneuse oksigenasie en dus arteriële oksigenasie tydens eenlongnarkose verbeter, of sou dit aftakking en arteriële oksigenasie versleg tydens eenlongnarkose? Kontrole groep Pulmonêre elastansie het tussen 18 en 36% verhoog en gemene pulmonale arterie druk het met 32% tydens eenlongnarkose vermeerder. Die verhoging in gemene pulmonale arterie druk met die aanvang van eenlongnarkose is groter as die waardes gesien deur sekere navorsers maar gelyk met waardes gevind in pasiënte met beskadigde longe. Die vraag ontstaan dan hoekom styg pulmonale arterie druk tydens eenlongnarkose? volgens Ohm se Wet, mag druk as die veelvoud van vloei en weerstand beskou word. Die verhoging in gemene pulmonale arterie druk tydens eenlongnarkose is daarvolgens hoofsaaklik te wyte aan twee redes. 1. Eerstens, die kurwe van druk teenoor vloei is waarskynlik styler tydens eenlongnarkose. Hierdie is omdat pulmonale vaskulêre werwing en verwyding (pulmonale vaskulêre reserwe) is meer beperk as nornaal in pasiënte met longsiekte. Hierdie is die waarskynlikste rede hoekom pulmonale arterie druk tydens eenlongnarkose verhoog. Die redes hoekom die pulmonale vaskulêre reserwe in die onderste long tydens eenlongnarkose beperk is sluit in die volgende: 1.1 Die pulmonale vaskulêre bed van pasiënte onderwerp aan eenlongnarkose mag abnormaal wees weens die onderliggende long patologie, 1.2 Tydens eenlongnarkose in die laterale decubitus posisie, is long volume in hoë mate verminder as tydens tweelongnarkose, 1.3 Die voorafgenoemde vermindering in longvolume sal verder verminder word deur wanposisies van die dubbellumenbuis, sekresies en bloed, en absorpsie atelektase. 1.4 Te hoë vlakke van PEEP, oftewel intrinsiek of ekstrensiek van oorsprong, sal die intraalveolêre vate toedruk en so die pulmonale vaskulêre weerstand verhoog. 2. Tweedens, is daar groter vloei deur hierdie vaskulêre bed wat ‘n hoër weerstand bevat. Dit is opmerkingswaardig dat die verhoging in gemene pulmonale arterie druk ‘n waarde van 25 mmHg nie oorskry het nie tydens eenlongnarkose, alhoewel kardiale omset met 30% verhoog het. In pasiënte met beskadigde longe, het vorige studies egter bewys dat groter verhoging in PA druk gebeur tydens afbinding van die pulmonale arterie. Die vraag ontstaan dus hoekom daar verskille bestaan tussen wat gebeur tydens afbind van die pulmonale arterie en eenlongnarkose? Die antwoord mag wees dat die beperking in die styging in PA druk tydens eenlongnarkose as gevolg van ‘n progressiewe afleiding van bloedvloei na die nie-geventileerde long gebeur sodra pulmonale arterie druk styg tydens eenlongnarkose. Die implikasie van die afleiding van bloed na die nie geventileerde long is dat dit as ‘n veiligheids meganisme optree en verdere styging in pulmonale arterie druk beperk tydens eenlongnarkose. Hierdie afblaas meganisme sal die regter ventrikel beskerm tot en met PA afbind.Kontrole groep: eenlongnarkose en regter ventrikulêre funksie Die huidige studie bied die geleentheid om die betekenis van die voorafgenoemde verhoging in PA drukke en elastansie op regter ventrikulêre funksie tydens eenlongnarkose te ondersoek. Die huidige studie dui aan dat die 30% verhoging in pulmonale arterie druk wat met die aanvang van eenlongnarkose plaasvind, glad nie regter ventrikulêre funksie belemmer nie indien dit vergelyk word met die basislyn wakker staat. In teendeel, kardiale omset het verhoog na chirurgiese insnyding: hierdie verhoging is waarskynlik te wyte aan simpatiese senuwee stimulasie na die chirurgiese insnyding. Hierdie waarnemings pas in ook met ander studies waartydens regter ventrikulêre ejeksie alleenlik begin om af te neem indien die indekse van opposisie tot regter ventrikulêre ejeksie 200 tot 250% van basislyn bereik. Verder, die induksie van voorlading, naamlik sentrale veneuse druk, pulmonale arterie wigdruk en regter ventrikulêre einddiastoliese volumes is onveranderd tydens die huidige studie; dit beteken die ventrikel het nie gedilateer het nie tydens die verhoging in regter ventrikulêre nalading. Die verband tussen slagwerk en nalading sal varieer, afhanklik van die kontraktiele status van die ventrikel. In hierdie opsig, kon ons aflei dat die regter ventrikel, onder omstandighede wat tydens diė studie plaasgevind het, gefunksioneer het op die stygende been van die verband tussen regter ventrikulêre slagwerk en pulmonale arterie elastansie. Hierdie waarneming ondersteun die argument in die vorige paragraaf dat die regter ventrikel funksie behoue is tydens eenlongnarkose. Ter opsomming omtrent die indekse van opposisie tot pulmonale vloei en regter ventrikulêre funksie tydens eenlongnarkose: 1. Opposisie tot regter ventrikulêre uitwerp verhoog. Die bewys hiervoor is ’n 30% verhoging in gemene pulmonale arterie druk en ’n 36% verhoging in pulmonale arterie elastansie. 2. Ten spyte van die verhoging in weerstand teen RV uitwerping, het regter ventrikulêre funksie (soos bepaal deur regter ventrikulêre slagwerk indeks, regter ventrikulêre ejeksie fraksie en slag volume), nie verminder tydens eenlongnarkose in vergelyking met die waardes verkry wanneer die pasiënte wakker is of aan tweelongnarkose onderwerp is. 3. Ons kon ook aflei dat die koppeling tussen die regter ventrikel en sy lading goed behoue is tydens eenlongnarkose. Die implikasie hiervan is dat regter ventrikulêre slagwerk reserwe teenwoordig is tydens eenlongnarkose. Tydens eenlongnarkose funksioneer die regter ventrikel as ’n vloeipomp, net soos in normale lewe; dit beteken dat en die klein verhoging in regter ventrikulêre nalading wat ondervind word tydens eenlongnarkose maklik getolereer word. Dobutamien tydens eenlongnarkose: opposisie tot pulmonale vloei en regter ventrikulêre funksie Die uitwerking van dobutamien op regter ventrikulêre funksie tydens eenlongnarkose kan as volg opgesom word: 1. Lae dosisse dobutamien (3 μg.kg-1.min-1) verhoog kardiale omset, slagvolume en regter ventrikulêre slagwerkindeks. Die toediening van dobutamien 3 μg.kg-1.min-1 het nie saamgegaan met ‘n verhoging in regter ventrikulêre nalading nie. Dus, lae dosisse van dobutamien het wel die koppeling tussen die regter ventrikel en die pulmonale vaskulatuur tydens eenlongnarkose verbeter.2. Nietemin, albei die hoër dosisse van dobutamien (5 en 7 μg.kg-1.min-1) tydens eenlongnarkose het verhogings in die opposisie tot pulmonale bloedvloei teweeggebring. Byvoorbeeld, PA elastansie, gemene PA druk en pulmonale vaskulêre weerstand het met 30 tot 40% verhoog in vergelyking met die waardes gekry toe die pasiënte wakker was en toe albei longe geventileer is. ’n Belangrike opmerking in hierdie opsig is dat pulmonale arterie vervormbaarheid tydens eenlongnarkose met 61% verminder het tydens albei dobutamien 5 en 7 μg.kg-1.min-1. Die verhogings in gemene pulmonale arterie druk en pulmonale vaskulêre weerstand is, volgens mening, nie van kliniese of statistiese betekenis nie, alhoewel die vermindering in PA vervormbaarheid tydens die dobutamien 7 μg.kg-1.min-1 infusie wel van kliniese betekenis is. PA vervormbaarheid weerspieël een van die faktore wat vaskulêre impedansie in die 3- element Windkessel model van sirkulasie het. Die verhoging in opposisie tot pulmonale vloei en die afwesigheid van progressiewe verhogings in indekse van regter ventrikulêre funksie is nie wat verwag word indien die dosisse van die inotroop en pulmonale vasodilator dobutamien, progressief verhoog word. Die redes hoekom die opposisie tot pulmonale vloei verhoog tydens die toediening van dobutamien sluit in die uitwissing van die pulmonale vaskulêre reserwe tydens eenlongnarkose. Tydens die hoë kardiale indekse van 5 tot 5.5 μg.kg-1.min-1. is die pulmonale vaskulêre reserwe uitgeput en die meganisme het die verwagte pulmonale vaskulêre vasodilatasie van dobutamien oorskadu. Bowendien is dit waarskynlik dat die verhoging in regter ventrikulêre nalading betekenisvol genoeg was om te verhoed dat regter ventrikulêre funksie progressief verhoog soos sou verwag word met die administrasie van hoër dosisse inotroop. Die administrasie van dobutamien tydens eenlongnarkose het gemene pulmonale arterie druk verhoog tot ’n maksimum van 24,9 ± 6.2 mm Hg teen ’n kardiale indeks van 5.5 ± 1.2 l.min-1.m2. Nietemin is gemene pulmonale arterie druk 24.0 ± 7.7 mm Hg teen die maksimum kardiale indeks in die kontrole groep van 4.4 ± 1.1 l.min-1.m-2 tydens eenlongnarkose in die kontrole groep. Hierdie weerspieël dus ’n relatief beperkte verhoging in pulmonale arterie druk in vergelyking met die verhoging in pulmonale arterie druk wat gebeur het tydens die administrasie van dobutamien. Die waarskynlikste rede hoekom daar ’n beperkte verhoging in pulmonale arterie druk sou gewees het tydens die infusie van dobutamien is die afblaas effek van die nie-geventileerde long wat die verhoging in PA druk beperk het. Oksigenasie tydens eenlongnarkose Die volgende waarnemings is gemaak in verband met suurstof vloed, veneuse en arteriële oksigenasie tydens eenlongnarkose in die kontrole groep: 1. Die kombinasie van Induksie van narkose en die 1ºC vermindering in temperatuur het saamgegaan met ’n 40% vermindering in suurstof verbruik tydens twee long narkose. Hierdie vermindering in suurstof verbruik het voortgegaan tydens eenlongnarkose. 2. Die aanvang van eenlongnarkose is geassosieerd met ’n verhoging in kardiale omset in vergelyking met albei die basislyn eenlongnarkose en wakker state. 3. Die gevolge van punte 1 en 2 hierbo is dat die gemengde veneuse suurstof saturasie vanaf 75% en die gemeng veneuse suurstof spanning vanaf 5.4 kPa (toe die pasiënte wakker was) gestyg het tydens4. Tydens eenlongnarkose het die betekenisvolle verhoging in veneuse oksigenasie veroorsaak dat daar ’n verhoging in arteriële oksigenasie was in vergelyking met wanneer die pasiënte wakker was. Hierdie styging in arteriele oksigenasie was ten spyte van die 37% aftakking wat teenwoordig was tydens eenlongnarkose. 5. Onder toestande in die huidige studie, het dobutamien tydens eenlongnarkose nog arteriële nog veneuse oksigenasie verbeter nie, maar die arteriele oksigenasie het konstant gebly. ’n Belangrike observasie wat daarmee saamgaan is dat dobutamien toediening nie met ’n daling in arteriële suurstof spanning geassosieer is nie. Vervolgens, die hipotese dat die verhoging in kardiale omset geassosieer met dobutamien toediening tydens eenlongnarkose ’n verhoging in arteriële oksigenasie beweeg bring, is dus verwerp. Die verwerping van die hipotese van die deel van die studie beteken dat die bevindinge die teenoorgestelde is van die studies gepubliseer deur Mathru en sy kollegas en Nomoto en Kawamura. Hierdie outeurs het gedemonstreer dat die toediening van inotrope ’n verhoging in arteriële oksigenasie teweeg gebring het. Nietemin is die teenoorgestelde gevolgtrekkinge nie teenstrydig met mekaar nie. Inteendeel hierdie verskille help ons om die effek van ’n verhoging in kardiale omset of arteriële oksigenasie in die teenwoordigheid van ’n betekenisvolle aftakking duidelik te maak. Die verskille tussen die studies kan op die volgende manier verduidelik word. Toestande wat in die huidige studie teenwoordig was het veroorsaak dat die verband tussen suurstof lewering en verbruik baie hoog was en dat die gemeng veneuse suurstof spanning baie hoog was om mee te begin alvorens dobutamien geinfuseer is. Dus is die veneuse saturasies op die plat deel van albei die suurstof dissosiasie kurwe en ook van die verband tussen kardiale omset en arteriële suurstof inhoud oorspronklik deur Kelman, Nunn en kollegas beskryf. Verdere verhogings in kardiale omset sou dus nie verwag word, en het nie, verhogings in gemeng veneuse suurstof spanning, gemeng veneuse suurstof saturasie of gemeng veneuse suurstof inhoud teweeg gebring. Dus, arteriële suurstof inhoud en saturasie het nie verander na die verhoging in kardiale omset wat teweeg gebring is deur die toediening van dobutamien in die huidige studie. Inteendeel, in die studie deur Mathru en kollegas, is die lae aanvanklike veneuse saturasie en spanning verbeter deur verhogings in die verband tussen suurstoflewering en suurstofverbruik. Omdat die veneuse saturasie aan die begin van die Mathru studie laag was, is betekenisvolle voordeel in arterieël oksigenasie teweeg gebring deur om die kardiale omset te verhoog. ’n Groot bekommernis vir die klinikus is dat die aftakking mag verhoog met die toediening van die inotroop dobutamien tydens eenlongnarkose en, op die manier, arteriële oksigenasie mag verminder. Die invloed van dobutamien op arteriële oksigenasie tydens eenlongnarkose mag teoreties te wyte wees aan die balans van die volgende uiteenlopende faktore: 1. Deur om die verband tussen suurstof lewering en verbruik te verbeter, sal dobutamien gemeng veneuse suurstof spanning verhoog. Hierdie verhoging sal arteriële oksigenasie verbeter in die teenwoordigheid van ’n groot aftakking, 2. Die bogenoemde moet teenoor potensiële verhogings in suurstofverbruik deur dobutamien oorweeg word. Die gevolge hiervan sou potensieel ’n vermindering in gemeng veneuse suurstof spanning wees. Sulke verhogings in suurstof verbruik is nie tydens die huidige studie gesien nie,3. ’n Verhoging in pulmonale arterie druk wat saamgaan met die verhoogde kardiale omset sal hipoksiese pulmonale vasokonstriksie teenwerk wat die aftakking in albei die geventileerde en nie geventileerde longe sal verhoog, 4. Direkte inhibisie van hipoksiese pulmonale vasokonstriksie deur dobutamien en, 5. Die invloed van gemeng veneuse suurstof spanning op hipoksiese pulmonale vasokonstriksie moet ook oorweeg word (d.i. hoe gemeng veneuse suurstof parsiele druk sal hipoksiese pulmonale vasokonstriksie inhibeer). Nietemin, ten spyte van die bekommernisse rondom hipoksemie tydens die toediening van dobutamien tydens eenlongnarkose, het dobutamien toediening nie ’n verlaging in arteriële suurstof spanning teweeg gebring nie, en ook het dit nie die koste van oksigenasie verhoog nie. Verder, die bevindinge van studies tydens eenlongnarkose in die laterale decubitus posisie deur Mathru en sy kollegas, Nomota en Kawamura en ook die huidige studie, dui aan dat die toediening van lae dosisse van dobutamien nie toe ’n verhoging in aftakking lei nie. Inteendeel, die voordelige effekte van die verhoging in kardiale omset op veneuse saturasie het veroorsaak dat daar ’n verhoging in arteriële saturasie is in die studie deur Mathru en sy kollegas soortgelyke meganismes is waarskynlik ook van toepassing in die studie wat gedoen is deur Nomoto en Kawamura. Dus, dwars deur die literatuur, is daar geen huidiglike bewys dat die toediening van dobutamien tot en met dosisse van 7μg.kg-1.min-1 aftakking verhoog of arteriële oksigenasie versleg in mense onderworpe aan eenlongnarkose in die laterale decubitus posisie. Dit is duidelik dat die vasodilatoriese effekte van dobutamien wat moontlik ’n verhoging in aftakking fraksie teweeg kan bring, nie die enigste faktore is om te oorweeg wanneer die middel se invloed op arteriële oksigenasie bestudeer word nie. Dit is ook van kliniese belang om die invloed van inotrope middels op veneuse suurstof inhoud te oorweeg. Dit is moontlik dat ’n aftakking verhoog kan word deur die toediening van ’n inotroop. Nietemin, mag die negatiewe effek wat die toediening van ’n inotroop sal inhou op arteriële oksigenasie deur middel van sy verhoging in aftakking, negeer word indien veneuse oksigenasie voordelig beïnvloed is. Verder, indien die verhoging in veneuse oksigenasie wat teweeggebring word deur die toediening van inotrope baie betekenisvol is, mag die gevolg hiervan wees dat arteriële oksigenasie voordelig beïnvloed word soos die geval in die huidige studie was. Die huidige benadering waar die kwaliteit van die bloed wat deur die aftakking vloei die arteriële oksigenasie beïnvloed, skuif die klem van voorkoming en behandeling van hipoksemie tydens eenlongnarkose van die long na die toereikendheid van die sirkulasie. Met ander woorde, die klem is geskuif van wat gebeur in die nie-geventileerde long (hipoksie pulmonale vasokonstriksie) tot primêr die toereikendheid van suurstof flux tydens eenlongnarkose. Ekstrinsieke en intrinsieke PEEP tydens eenlongnarkose Die invloed van PEEP op hemodinamika en oksigenasie tydens eenlongnarkose in die huidige studie mag as volg opgesom word. Toe PEEP5 tydens eenlongnarkose toegedien is: 1. Nie regter ventrikulêre funksie, hemodinamika, suurstof flux nog arteriële oksigenasie is beïnvloed deur die toediening van PEEP5 in vergelyking met die stap wanneer geen eksterne PEEP toegedien is nie. 2. Betekenisvolle hoeveelhede intrinsieke PEEP is teenwoordig tydens eenlongnarkose in die kontrole groep.Die hoeveelheid intrinsieke PEEP wat teenwoordig was, is swak maar betekenisvol verwant aan die graad obstruktiewe lugwegsiekte wat teenwoordig was gemeet deur pre-operatiewe longfunksie toetse. 3. Die waarskynlikste rede hoekom PEEP5 nie ’n verskil gemaak het aan oksigenasie of hemodinamika nie is die teenwoordigheid van soortgelyke hoeveelhede intrinsieke PEEP tydens eenlongnarkose. Hierdie bevinding bevestig Myle’s se beweringe dat lae vlakke intrinsieke PEEP voordelige effekte op oksigenasie tydens eenlongnarkose mag hê. PEEP10 toediening aan die onderlong tydens eenlongnarkose in die huidige studie het tot ’n vermindering in slagvolume gelei. Hierdie vermindering is primêr veroorsaak deur ’n vermindering in voorlading en nie die gevolg van ’n verhoging in pulmonale vaskulêre weerstand nie. Die gevolgtrekking is gemaak omdat regerventrikulere enddiastoliese volume verlaag het maar pulmonale vaskulêre weerstand het nie verhoog tot vlakke wat bekend is om regter ventrikulêre funksie te belemmer nie. Die vermindering in die verhouding tussen suurstof lewering en suurstof verbruik wat geïnduseer is deur PEEP10 het (voorspelbaar) gemeng veneuse suurstof spanning verminder en kon potensieël gelei het tot belemmering in arteriële oksigenasie. Indien minder voordelige sirkulatoriese toestande geheers het tydens die huidige studie, sou groter (oorbodige) hoeveelhede PEEP slegter kardiorespiratoriese gevolge tot gevolg gehad het. Ter opsomming, optimalisering van die volume van die onderlong tydens eenlongnarkose speel ’n belangrike rol in die bepaling van arteriële oksigenasie. Nietemin, die terapeutiese indeks vir PEEP is nou en die narkotiseur het die behoefte om te weet wanneer die volume van die onderlong optimaal is. In die opsig, is ’n betekenisvolle probleem tydens eenlongnarkose dat meting van funksionele residuele kapasiteit nie huidiglik maklik is nie

This study examined the effects of lung expansion and changes in temperature on fluid movement by the lungs in the initial period after birth. In addition, experiments with amiloride support the belief that fluid reabsorption acts via a sodium transport mechanism. Lungs from fetal guinea pigs (56-67 days of gestation) were supported in vitro for three hours, and lung liquid production rates were measured using a dye dilution technique. The average production rate in the first hour of untreated preparations was 1.30 ±0.22 ml/kg body weight per hour, and this did not change significantly during the remainder of the experiment (n=30). This rate is comparable to secretion rates previously reported from chronically catheterized sheep. In 36 further preparations, the lungs were transferred from 37°C to fresh Krebs-Hanseleit saline at one of the following temperatures, for one hour (an ABA design): (a) 29°C; (b) 32°C; (c) 34°C; (d) 35°C; (e) 36°C; (f) 39°C. In all cases, the temperature change resulted in an immediate and significant fall in secretion. All lungs showed a tendency towards recovery when returned to starting conditions, except those subjected to a temperature increase. Reductions of 2-3°C, those normally seen in the delivery room, had the greatest effect and caused not only a decrease in secretion, but promoted fluid reabsorption. Amiloride at 10⁻⁶M had no effect on control preparations, but completely blocked the reabsorption stimulated by a temperature drop of 2°C. Expansion of the lungs, which occurs naturally as a newborn attempts to take its first breaths, was also examined. Thirty fetal lungs were expanded by one of the following amounts: (a) 18%; (b) 31%; (c) 43%; (d) 50%; (e) 72%. All expansions resulted in a significant fall in secretion rate, with the effect being proportional to the degree of expansion. Amiloride at 10⁻⁶M again blocked the strong reabsorption occurring with 70% expansion. Further studies investigated the possibility that expansion causes reabsorption via the local release of a substance occurring in the lungs. When one set of lungs was expanded in the presence of a second, unexpanded set, both showed a significant decrease in secretion, suggesting that the expanded lung had released some factor which affected the otherwise untreated lung. However, studies with α- and β- adrenergic blockers showed that it is unlikely the expanded lung was liberating either adrenaline or nor-adrenaline. The results of this study show that two changes which are likely to occur in the period immediately after birth, namely a 2-3°C decrease in core temperature, and lung expansion, may be important in promoting the vital reabsorption of fluid. They suggest that expansion may release substances locally in the lungs which stimulate this reabsorption, and that the fluid is removed from the potential air spaces via sodium transport mechanisms.
Science, Faculty of
Zoology, Department of
Graduate

This study was designed to examine the hypothesis that the amount of amniotic fluid present during gestation is critical to normal lung growth and maturation. On day 16 of gestation the amniotic sacs of the right or left uterine horns of timed pregnant Sprague-Dawley rats were punctured with a 20 gauge needle. The fetuses of the opposite horn served as controls. On day 21 of gestation (one day prior to natural delivery) the fetuses were delivered by Cesarean section. An unbalanced, mixed model analysis of variance was performed on the data collected from each fetus. Probability values of less than 0.05 between control and experimental animals were considered significant. Amniotic sac puncture resulted in a significant loss of amniotic fluid as indicated by reduced amniotic fluid volume on day 21. Experimental body weight was significantly reduced indicating fetal growth retardation. Lung growth was also retarded as indicated by significantly reduced lung weight to body weight ratios and lung volume to body weight ratios following amniotic sac puncture. There was a reduction in the amount of fluid present within the experimental lungs. There appeared to be no significant effect on the structural units of the lung as indicated by no significant difference between control and experimental fetal lungs in terms of cell number, cell size, total protein to body weight ratio, maturation of type II cells, volume fraction of saccular air, saccular wall, conducting air and nonparenchyma, airspace size, saccular surface area to body weight ratio and surface to volume ratio. Thus, loss of amniotic fluid significantly affected lung growth, more than it affected overall body growth, without having an effect on lung maturation.
Medicine, Faculty of
Pathology and Laboratory Medicine, Department of
Graduate

The effect of lateral electron disequilibrium on patient dose has been investigated. This has been achieved by dosimetry in lung and air cavity phantoms at megavoltage x-ray energies. The scatter function photon beam models for tissue inhomogeneity, such as the ETAR correction algorithm, currently implemented in commercial treatment planning systems do not predict the dose distribution accurately in many situations where lateral electron equilibrium does not exist. The lung phantom is made up of solid water slabs and lung analogue slabs. Using a thimble ionization chamber, a Markus ionization chamber and TLDs the problems of central axis dose reduction and penumbral flaring in lung for x-rays have been investigated. It is found that the ETAR correction predicts the dose at mid lung with varying degrees of accuracy depending on the field size. It was found that internal body cavities, depending on their size, experience underdose or overdose in the distal surfaces of the cavities when compared with the results predicted by an ETAR correction algorithm. Therefore, this energy is not recommended for use in situations where cavities arise
Master of Science (Hons)

Thesis (Ph. D.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains ix, 132 p. : ill. (some col.) Vita. Includes abstract. Includes bibliographical references.

Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Joseph M. Le Doux; Committee Member: Andrés J. Garcia; Committee Member: Cheng Zhu; Committee Member: Nael McCarty; Committee Member: Richard Compans. Part of the SMARTech Electronic Thesis and Dissertation Collection.

The clinical pilot study enrolled 26 infants and measured IL-8, TNF-α and inflammatory cells in bronchoalveolar lavage samples. The results demonstrated that it may be possible to predict a group of babies at extremely high risk for developing chronic lung disease by early measurement of IL-8 in tracheal secretions. To further investigate the role of the genital mycoplasmas, Ureaplasma urealyticum and Mycoplasma hominis, a randomised study using an effective antibiotic, erythromycin, was carried out. A low grade untreated infection could persistently stimulate an in vivo inflammatory response, but we also wished to investigate the reported anti-inflammatory properties of erythromycin. The infection rate in the study was lower than expected (12% compared to 30% in a pilot study) and did not correlate with outcome. There was also no correlation between outcome and treatment and the inflammatory response, as measured by IL-8, did not correlate with outcome as it had in our pilot study. As part of a randomised trial of a natural and synthetic surfactant taking place on our unit, bronchoalveolar lavage samples both pre and post surfactant were analysed for cytokines and cells. Our results showed that Curosurf produced a significantly lower inflammatory response compared to Exosurf 24 hours after administration but there was no correlation between surfactant type and development of chronic lung disease. The cell population present in the lung effluent has been an area of controversy. Standard cytospin smears of bronchoalveolar lavage samples were compared using a differential stain and an immunocytochemical stain which relies on monoclonal antibodies to identify specific cell surface markers. Our results confirm that the differential stain identifies neutrophils but it significantly under-estimates cells of the monocyte/macrophage lineage. Laboratory investigations were carried out to further elucidate and quantify the response of A549 human lung epithelial cells to Ureaplasma urealyticum, and other genital isolates, a Gram-positive (Staphylococcus albus) and a Gram-negative (Eschericia coli). The cells were stimulated in the presence of TNF-α and high oxygen concentrations, and with used in the clinical management of these infants, including surfactants, antibodies and steroids.

The effect of lateral electron disequilibrium on patient dose has been investigated. This has been achieved by dosimetry in lung and air cavity phantoms at megavoltage x-ray energies. The scatter function photon beam models for tissue inhomogeneity, such as the ETAR correction algorithm, currently implemented in commercial treatment planning systems do not predict the dose distribution accurately in many situations where lateral electron equilibrium does not exist. The lung phantom is made up of solid water slabs and lung analogue slabs. Using a thimble ionization chamber, a Markus ionization chamber and TLDs the problems of central axis dose reduction and penumbral flaring in lung for x-rays have been investigated. It is found that the ETAR correction predicts the dose at mid lung with varying degrees of accuracy depending on the field size. It was found that internal body cavities, depending on their size, experience underdose or overdose in the distal surfaces of the cavities when compared with the results predicted by an ETAR correction algorithm. Therefore, this energy is not recommended for use in situations where cavities arise

This study examined the relationship between lung capacity, speech volume and duration of utterances. 8 adult subjects, 4 males and 4 females (24-36 yrs), participated. By breathing into a digital spirometer, lung capacities such as Vital Capacity (VC) and Inspirational Capacity (IC) were estimated. Respiratory movements were measured using Respiratory Inductance Plethysmography (RIP), and these respiratory movements were calibrated in litres using the spirometer. The proportion of lung capacity used for speech was estimated from the calibrated RIP signals during reading of a nonsense text without punctuation marks. This proportion was defined as the median volume of exhaled air per utterance (SV) (in litres) during text reading, divided by the speaker’s VC (SV/VC). Utterance durations (UD) and Respiratory Rates (RR) were estimated from acoustic recordings of the text readings as well as the RIP signals, displayed in Praat. This allowed investigating the relationships between lung capacity, respiratory rate, utterance durations as well as the proportion of lung capacity used for speech. Put differently, the question was whether people with larger lungs speak in longer utterances and inhale less frequently, as well as whether people with smaller lungs use a relatively larger proportion of their lung capacity for speaking. Additionally, where SV initiated (SVIN) and terminated (SVTER) within VC was calculated based on the RIP signals. There were no significant relationships between VC and UD or RR. In addition, there was no significant relationship between SV/VC and VC. SVIN ranged from 43%-71% and SVTER ranged from 17%-55%. The results indicate no relationship between VC and UD or RR nor that people with a smaller VC use more of it for speech. The range of SV within VC suggest that people maintain a fairly relaxed state with regards to muscle pressure.

Thesis (Ph. D.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains xvi, 250 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Chemoattractant agents play a crucial role in the initiation of immune responses, by regulating the traffic and function of leucocyte populations. Their receptors are therefore considered as potential targets for the development of new therapies in the fields of cancer and inflammatory diseases. ChemR23, a previously orphan receptor discovered in the laboratory, is structurally related to receptors for chemoattractant agents. It is expressed on immature myeloid and plasmacytoid dendritic cells (mDCs and pDCs respectively), as well as on adipocytes, macrophages, NK and endothelial cells. Chemerin, the endogenous ligand of ChemR23, is abundant in various human samples originating from inflammatory diseases, including pleural effusions. Chemerin is secreted as an inactive precursor, prochemerin, and is activated by the removal of six or seven amino-acids from its carboxy-terminus by serine proteases, such as as cathepsin G and elastase. Chemerin acts as a chemoattractant agent of low nanomolar potency for macrophages, immature mDCs and pDCs. It is however more active on pDCs, in line with the higher expression of ChemR23 on these cells. pDCs possess important immunoregulatory properties in lung diseases, and their ability to secrete large amounts of type I interferon (IFN) upon viral infection makes them crucial players in anti-viral immunity.

According to these elements, and to the role of neutrophils in the physiopathology of many inflammatory lung diseases and in the generation of active chemerin, we began in 2007 to study the role of chemerin and its receptor ChemR23 in inflammatory lung diseases. We first characterized the mouse chemerin/ChemR23 system, and described that this system was very similar to the human one, in terms of distribution, pharmacology and functional properties. We then used wild type mice (WT) and mice invalidated for the receptor (ChemR23-/-) in various models of inflammatory lung diseases, including asthma, lung fibrosis, viral pneumonia, and acute lung injury.

Whereas the asthma and lung fibrosis models did not allow to demonstrate a significant role of the chemerin/ChemR23 system (possibly as a result of the lack of production of active chemerin in these models), infection by either the Pneumonia Virus of Mice (PVM), the mouse counterpart of human RSV, or by a murinized H1N1 influenza strain resulted in a significantly higher mortality rate in ChemR23-/- mice as compared to their WT counterparts. Using the PVM-induced pneumonia model, we observed that the excessive mortality of knock-out mice is caused by an inadequate and excessive innate immune response characterized by a massive recruitment of neutrophils to the lungs, associated with a delayed viral clearance and lower type I IFN synthesis. This latter observation suggested an impairment of pDC recruitment, according to the important contribution of pDCs to the production of type I IFNs in viral diseases, and the role of chemerin in the recruitment of these cells. We indeed confirmed a lower recruitment of pDCs in the lung of infected ChemR23-/- mice, as compared to WT mice. However, experiments of adoptive transfert and depletion of pDCs failed to proof a link between impaired pDC recruitment and the excessive morbidity and mortality observed in ChemR23-invalidated mice.

In parallel, we studied the role of the chemerin/ChemR23 system in the control of innate immune responses, by using a model of acute lung injury caused by the intra-tracheal instillation of bacterial lipopolysaccharide (LPS). In this model, administration of recombinant chemerin together with LPS in WT mice resulted in a significant (about 50%) reduction of neutrophil recruitment to both lung parenchyma and airways. Assessment of pro-inflammatory cytokines and chemokines in broncho-alveolar lavage fluids confirmed this anti-inflammatory effect of chemerin, which was ChemR23-dependent, as the inflammatory response of ChemR23-/- mice was unaffected by chemerin. In our hands, chemerin does not modulate macrophage functions, in contrast to data recently published by other groups, attributing anti-inflammatory effects of chemerin or chemerin-derived peptide to the modulation of macrophage activation and phagocytosis. Other hypotheses that could take our observations into account are presently investigated, including an immunomodulatory role of chemerin on lung epithelial or endothelial cells, and/or the ChemR23-dependent recruitment of subtypes of macrophages or other myeloid cells endowed with immunosuppressive properties.

In conclusion, our studies characterized the mouse chemerin/ChemR23 system and highlighted the role of this system in the physiopathology of some inflammatory lung diseases. Our results suggest that the chemerin/ChemR23 system might be considered as a potential therapeutic target for the development of future anti-infectious and anti-inflammatory therapies, particularly for viral pneumonia, which represent a major public health problem, as well as for acute respiratory distress syndrome (ARDS) following severe acute lung injuries.

Les agents chimioattractants jouent un rôle fondamental dans l’initiation des réponses immunes en régulant le trafic et la fonction des populations leucocytaires. Leurs récepteurs constituent dès lors des cibles d’intérêt pour le développement de traitements contre les maladies inflammatoires et le cancer. Le laboratoire d’accueil a identifié le récepteur ChemR23, exprimé à la surface des cellules dendritiques myéloïdes (mDCs) et plasmacytoïdes (pDCs) immatures, des macrophages, des cellules NK, des adipocytes, et des cellules endothéliales. Le ligand endogène du récepteur ChemR23, la chémérine, est présent en abondance dans divers échantillons pathologiques d’origine inflammatoire. La chémérine est produite sous la forme d'un précurseur inactif, la prochémérine, qui nécessite pour devenir active le clivage protéolytique de six ou sept acides aminés à son extrémité carboxy-terminale. La chémérine induit le chimiotactisme des macrophages et des DCs immatures, et en particulier des pDCs immatures en accord avec l’expression plus importante de ChemR23 par les pDCs. Les pDCs jouent un rôle immunorégulateur important en pathologie pulmonaire, en particulier dans la physiopathologie des pneumonies virales, par leur capacité à produire d’importantes quantités d’interféron (IFN) de type I.

Compte tenu de ces éléments et du rôle des polynucléaires neutrophiles dans de nombreuses pathologies pulmonaires, ainsi que dans la génération de chémérine active à partir de son précurseur, nous avons débuté en octobre 2007, l’étude du rôle de la chémérine et de son récepteur ChemR23 dans le contrôle des pathologies pulmonaires inflammatoires. Nous avons tout d’abord caractérisé le système chémérine/ChemR23 chez la souris et avons montré que ce système présentait des caractéristiques similaires à celles décrites chez l’homme, en termes de distribution, de pharmacologie et de propriétés fonctionnelles.

Ensuite, nous avons comparé des souris sauvages et invalidées pour le récepteur ChemR23 (ChemR23-/-) dans divers modèles de pathologies pulmonaires. Les modèles d’asthme et de fibrose pulmonaire induite par instillation de bléomycine ou de silice n’ont pas permis de mettre en évidence un rôle important du couple chémérine/ChemR23, peut-être en raison de l’absence de génération de forme active de chémérine dans ces modèles. En revanche, l’administration de deux agents viraux différents, le PVM (Pneumonia Virus of Mice), l’équivalent murin du RSV humain, et un virus de l’influenza H1N1 murinisé, a résulté en un taux de mortalité 40% plus élevé pour les souris ChemR23-/- par rapport à leurs homologues sauvages. En utilisant le modèle de pneumonie induite par le PVM, nous avons montré que cette différence de mortalité est causée par une réponse immune inappropriée et excessive, associée à une réduction de l’élimination du virus, ainsi qu’à un déficit de synthèse d’IFN de type I. Les pDCs, dans un contexte d’infection virale, sont capables de synthétiser d’importantes quantités d’IFN de type I, et nous avons mis en évidence un déficit relatif de recrutement en pDCs chez les souris ChemR23-/- infectées. Néanmoins, les expériences de transfert adoptif et de déplétion de pDCs n’ont pas permis de lier ce défaut de recrutement à l’excès de morbidité et de mortalité observé chez les souris ChemR23-/- infectées.

En parallèle, le rôle de ce couple ligand-récepteur dans le contrôle des réponses immunitaires innées a été étudié dans un modèle de pneumopathie aiguë induite par instillation intra-trachéale de lipopolysaccharide (LPS). Dans ce modèle, l’administration simultanée de chémérine recombinante avec le LPS entraîne chez les souris sauvages une diminution significative (environ 50%) du nombre de polynucléaires neutrophiles recrutés dans les voies aériennes et dans le parenchyme pulmonaire, ainsi qu’une importante diminution de synthèse de cytokines pro-inflammatoires. Cet effet anti-inflammatoire de la chémérine est dépendant de ChemR23, et ne semble pas être secondaire à un effet de la chémérine sur l’activation des macrophages, contrairement à certaines données publiées récemment par d’autres groupes. D’autres hypothèses permettraient cependant de prendre en compte ces observations, notamment un effet de la chémérine sur les cellules épithéliales et/ou endothéliales pulmonaires, ainsi que sur le recrutement de sous-populations de macrophages ou d’autres cellules myéloïdes possédant des propriétés immunosuppressives. Des expériences complémentaires ont été initiées afin de tester ces hypothèses.

En conclusion, après avoir caractérisé le système chémérine/ChemR23 chez la souris, nos études ont permis de mettre en évidence le rôle de ce couple ligand/récepteur dans la physiopathologie de certaines pneumopathies inflammatoires, ouvrant ainsi de nouvelles perspectives thérapeutiques, en particulier pour le traitement des pneumopathies virales, qui constituent un problème de santé publique majeur, ainsi que des syndromes de détresse respiratoire aiguë (ARDS).
Doctorat en Sciences médicales
info:eu-repo/semantics/nonPublished

Where is the Person in Symptom Cluster Research? The Experience of Symptom Clusters in Patients with Advanced Lung Cancer This thesis describes a three-year qualitative study which aimed to explore the experience of symptom clusters in patients with advanced lung cancer. The study employed a patient-focused approach utilising Interpretative Phenomenological Analysis (IPA) (Smith et al. 2009a). This methodology (IPA), informed by a contextual constructionist stance, was selected to explore the experience of symptom clusters, for its focus on the lived experience, the context and meanings which surround such experiences and its idiographic approach. Ten patients (a sample size which is the upper limit of the number of participants advocated for studies employing IPA (Smith et al. 2009b;Reid et al. 2005;Smith and Osborn 2004)) with advanced lung cancer took part in the study and data were collected using unstructured, in-depth interviews at two time points: on recruitment and three to five weeks later. Data were analysed using Interpretative Phenomenological Analysis, within the framework advocated by Smith and Osborn (2003). The study generated interesting and significant findings. The experience of symptom clusters in patients with advanced lung cancer was characterised by two super-ordinate themes: ‘The lived experience of symptom clusters and the role of context and meaning’ and ‘Symptom clusters and loss of sense of self’. The super-ordinate theme of ‘The lived experience of symptom clusters and the role of context and meaning’ in the first instance, illustrates that the participants in this study were experiencing symptom clusters and providing detail on the components, nature and patterning of the symptom clusters reported, particularly the way that one or two salient symptoms were commonly highlighted from all the other symptoms experienced. This super-ordinate theme also demonstrates the core role that context and meaning play in the lived experience of symptom clusters, with many of the participants in this study framing their experiences of symptom clusters within a fear of death, stigma and loss of sense of self. The second super-ordinate theme informing this thesis is ‘Symptom clusters and loss of sense of self’. This super-ordinate theme illustrates the impact of symptom clusters on the participants’ lives, and how this, in turn, impacted on their sense of self in a number of different ways. For some, their sense of self was compromised by the concurrent symptoms that they were experiencing, as they prevented them from undertaking roles and activities that they were accustomed to in the past. This super-ordinate theme also highlights the role of the body relative to the self, and describes how the participants’ sense of self was transiently lost during periods when they experienced symptom clusters of high severity. The findings presented also demonstrate the knock-on effect of loss of sense of self experienced, with the participants feeling like they were a burden due to their incapacitation, and at times hiding the multiple symptoms that they were experiencing, in a bid to protect their loved ones from their illness. In light of the loss of sense of self experienced, this super-ordinate theme also demonstrates how the participants employed various strategies in a bid to try and maintain a coherent and valued sense of self. The findings presented illustrate how the use of IPA facilitated the collection of data that provided an in-depth understanding of the complexity of the experience of symptom clusters in patients with advanced lung cancer, adding a unique contribution to this body of knowledge. The results of this study highlight the limitations of definitions that currently underpin the study of symptom clusters in patients with cancer and the current empirical base to date, particularly the way that they do not acknowledge the core role that context and meaning play in the lived experience of this phenomenon. This lack of recognition of these core elements of the patient experience of symptom clusters poses the risk of this body of research producing data that have limited relevance to the patient and therefore clinical practice. It is therefore proposed that the study of symptom clusters in patients with cancer needs to move away from the reductionist approach which currently dominates and to broaden its scope, to one that acknowledges the complexity of the experience of symptom clusters, the core role that context and meaning play in such experiences, and contributions that patient experience can make in advancing this important and emerging body of research.

Thesis (PhD (Medicine. Internal medicine))--University of Stellenbosch, 2007.
1.1. Background Tumors arising from the lung, pleura, or chest wall are a frequent problem in clinical pulmonary medicine. Most lesions are either infectious, neoplastic or granulomatous in nature, but a variety of other differential diagnoses must be considered. An accurate diagnosis is important because the available treatments differ substantially, and because any delay will impair the prognosis in potentially curable patients with lung carcinoma. The investigations involve the disciplines of radiology, pulmonology, surgery, microbiology, and anatomical pathology and consume a respectable amount of resources. The aim of the work covered in this thesis was to optimize the available diagnostic methods for the routine use in a health care setting with limited resources. 1.2. Methods The general idea of this work was to identify conventional sampling methods that could be developed further to become more useful for the diagnosis of chest tumors in a low resource health care setting. The key method was research performed: a) to revise and expand the indication for a sampling method, b) to technically improve the sampling process, and c) to optimize sample transport, preparation and analysis in collaboration with the analytical laboratory. 1.3. Results A list of invasive diagnostic procedures, imaging methods and analytical processes were developed, evaluated and integrated into clinical practice. A) transbronchial needle aspiration, B) transthoracic cutting needle biopsy, C) transthoracic fine needle aspiration, D) transthoracic ultrasound, and E) rapid on-site evaluation of needle aspirates by a cytopathologist. Five studies pertaining to this thesis were published in international peerreviewed journals: â ¢ Safety and yield of ultrasound-assisted transthoracic biopsy performed by pulmonologists (Respiration 2004;71:519-22) This paper established that ultrasound-assisted transthoracic biopsy performed by pulmonologists is feasible, safe, practical, low-cost and has a high yield. â ¢ Utility of rapid on-site evaluation of transbronchial needle aspirates (Respiration 2005;72:182-8) This paper demonstrated the economical advantages of on-site evaluation of transbronchial specimens in a low-resource setting. â ¢ Transbronchial needle aspirates: comparison of two preparation methods (Chest 2005;127:2015-8) This paper demonstrated that preparing smears on-site has a far better yield than pooling samples into a vial. This means that the yield is improved over the current standard at no additional cost. â ¢ Transbronchial needle aspirates: how many passes per target site? (European Respiratory Journal 2007;29:112-6) This paper investigated the most economical and effective approach to serial sampling with transbronchial needle aspiration during flexible bronchoscopy. â ¢ Ultrasound assisted transthoracic biopsy: fine needle aspiration or cutting needle biopsy? (European Respiratory Journal 2007;29:357-62) This paper compared two common methods of sampling and demonstrates that the less expensive method is sufficient in the majority of cases. 1.4. Conclusion This work has impacted on current practice in multiple ways. Conventional methods have been optimized by improving technical factors and with the integration of interdisciplinary collaboration. The initiated research is ongoing with the aim to achieve continued technical and economical improvements in the diagnosis of chest tumors.

Bibliography: leaves 168-184. The work in this study encompasses oxygen free radical related inflammation in the peripheral lung and in lung cells. Animal and human studies have been used. Methods include cell culture with function studies, protein chemistry, animal and human physiology, and cell and lung structure through histopathology, and various forms of electron microscopy. The work resulting from this thesis has formed an important basis for understanding acute and chronic lung injury.

[Truncated abstract] Urinary desmosines have been proposed as a biomarker for inflammatory lung damage. Desmosine, a breakdown product of elastin, is an effective marker of the degradation of elastin and has been studied in many disease scenarios where there is acute and chronic lung inflammation. Lung matrix degradation has been proven in vitro and in vivo with many experiments showing that the excess proteases degrades lung matrix. The secretion of proteases by neutrophils is an innate response of the body to the invasion by micro organisms and when secreted in excess, the protective anti-protease mechanism is swamped. Chronic inflammation and persistent infection eventually leads to bronchiectasis and respiratory failure. Urinary desmosine has been shown to be elevated in respiratory conditions with acute and chronic inflammation . . . Urinary desmosine levels in a large cohort of healthy children have been established using this method and predictive Z-score formulae have been developed to use in children with lung disease. Exploration of these scores in children with CF have shown that the levels of urinary desmosine appear to be sensitive to the clinical setting, where high urinary desmosine levels were present during exacerbation and significantly reduced when treated for infection with antibiotic therapy and physiotherapy. The study of young children under the age of seven was undertaken to determine if the urinary desmosine levels could indicate when lung damage was occurring and to determine what mechanisms might be involved. Since there appeared to be no apparent relationship between elevated desmosines and proteases in the lung in young children with CF, further studies are required to define the mechanisms behind increased elastin metabolism in those children.

The goal of conformal radiation techniques is to improve local tumour control through dose escalation to target volumes while at the same time sparing surrounding healthy tissue. Respiratory motion is known to be the largest intra-fractional organ motion and the most significant source of uncertainty in treatment planning for chest lesions. A method to account for the effects of respiratory motion is to use four-dimensional radiotherapy. While analytical models are useful, it is essential that the motion problem in radiotherapy is addressed by both modeling as well as experimentally studies so that different obstacles can be overcome before clinical implementation of a motion compensation method. Validation of techniques aimed at measuring and minimizing the effects of respiratory motion require a realistic dynamic deformable phantom for use as a gold standard. In this work we present the design, construction, performance and deformable image registration of a novel breathing, tissue equivalent phantom with a deformable lung that can reproducibly emulate 3D non-isotropic lung deformations according to any real lung-like breathing pattern. The phantom consists of a Lucite cylinder filled with water containing a latex balloon stuffed with dampened natural sponges. The balloon is attached to a piston that mimics the human diaphragm. Nylon wires and Lucite beads, emulating vascular and bronchial bifurcations, were glued at various locations, uniformly throughout the sponges. The phantom is capable of simulating programmed irregular breathing patterns with varying periods and amplitudes. A deformable, tissue equivalent tumour, suitable for holding radiochromic film for dose measurements was embedded in the sponge. Experiments for 3D motion assessment, motion reproducibility as well as deformable image registration and validation are presented using the deformable phantom.

In the first part of this master’s thesis an overview about lungs (anatomy, physiology and respiratory mechanics) is given. Next sections are focused on description of the mechanical lung simulator and the mobile circulatory module. The use, construction, function, observed parameters and control scheme of the mobile circulatory module is described. Control unit which is divided into separate modules is introduced including description of power supply and communication. In following chapters a description of DCNM (Direct Control and Notification Module) is given.

Les Malformations Adénomatoïdes Kystiques du Poumon (MAKP) sont les malformations pulmonaires congénitales les plus fréquentes. Leur diagnostic est anatomopathologique. Elles sont classées en type I si elles comportent de larges kystes (>2cm), en type II si elles contiennent de multiples kystes plus petits (<1cm). Les MAKP de type III ont un aspect plus solide et contiennent des structures immatures ressemblant au poumon en développement. En général asymptomatiques, les MAKP peuvent se compliquer in utero d'hydramnios ou d'anasarque, à la naissance de détresse respiratoire, et plus tardivement d'infections ou de pneumothorax. Leur potentielle dégénérescence maligne reste débattue. L'origine des MAKP est inconnue. Les avancées récentes suggèrent une anomalie transitoire et focale du développement pulmonaire, qui pourrait être secondaire à une obstruction des voies aériennes. Le rôle du Fibroblast Growth Factor 10 (FGF10), facteur indispensable à la formation des ramifications pulmonaires, est supporté par différents modèles animaux. La surexpression localisée du FGF10 pourrait induire des dilatations kystiques des voies aériennes.L'objectif de ce travail était de déterminer les anomalies moléculaires à l'origine des MAKP.Dans une approche molécule candidate, nous avons comparé par immunohistochimie l'expression du FGF10, de son récepteur le FGFR2b, et d'un de ses inhibiteurs, Sonic Hedgehog (SHH), entre MAKP et tissus témoins. Nous avons également comparé l'expression de l'ARNm du FGF10 dans des cultures de fibroblastes isolés à partir de MAKP et de tissus témoins. Nous avons enfin élaboré un modèle de ligature trachéale in-utéro de lapins fœtaux, afin de modéliser les MAKP et d'étudier in-vivo en fin de gestation (J29/31) les conséquences morphologiques et moléculaires d'une obstruction trachéale précoce (J23/31). Dans une approche sans à-priori, nous avons microdissequé des MAKP et des tissus témoins, afin de séparer les compartiments épithélial et mésenchymateux et de comparer les transcriptomes issus de ces 2 compartiments entre MAKP et tissus sains. Nous avons également recherché l'existence d'anomalies génétiques in-situ, en comparant par CGH array le génome du tissu pathologique à celui obtenu à partir du sang périphérique provenant du même patient.Aucune différence d'expression du FGF10, du FGFR2b et de SHH n'était observée en immunohistochimie, entre MAKP et témoins. L'expression ARNm du FGF10 était cependant plus élevée dans les fibroblastes de MAKP que dans les fibroblastes de tissus témoins. Nous n'avons pas observé de dilatation des voies aériennes de conduction chez les fœtus ligaturés, mais une augmentation du nombre des alvéoles pulmonaires. La voie de signalisation FGF10 n'était pas surexprimée à J29 dans le poumon des fœtus ligaturés. Les premiers résultats de l'analyse CGH array ne montrent pas de différence entre le génome provenant de la lésion et le génome provenant du sang périphérique. L'analyse transcriptomique est en cours.Le FGF10 n'est pas surexprimée de façon permanente dans les MAKP, mais il est possible que sa surexpression soit transitoire, et que notre analyse ait été trop tardive. L'occlusion trachéale précoce n'affecte pas les voies aériennes de conduction, notre modèle animal n'est pas un modèle de MAKP. Un modèle fondé sur une occlusion bronchique précoce, sur des explants de poumon fœtal serait probablement plus adapté à l'étude des MAKP. L'absence d'anomalie génétique confirme l'hypothèse d'une anomalie localisée et transitoire du développement pulmonaire à l'origine des MAKP
Les Malformations Adénomatoïdes Kystiques du Poumon (MAKP) sont les malformations pulmonaires congénitales les plus fréquentes. Leur diagnostic est anatomopathologique. Elles sont classées en type I si elles comportent de larges kystes (>2cm), en type II si elles contiennent de multiples kystes plus petits (<1cm). Les MAKP de type III ont un aspect plus solide et contiennent des structures immatures ressemblant au poumon en développement. En général asymptomatiques, les MAKP peuvent se compliquer in utero d'hydramnios ou d'anasarque, à la naissance de détresse respiratoire, et plus tardivement d'infections ou de pneumothorax. Leur potentielle dégénérescence maligne reste débattue. L'origine des MAKP est inconnue. Les avancées récentes suggèrent une anomalie transitoire et focale du développement pulmonaire, qui pourrait être secondaire à une obstruction des voies aériennes. Le rôle du Fibroblast Growth Factor 10 (FGF10), facteur indispensable à la formation des ramifications pulmonaires, est supporté par différents modèles animaux. La surexpression localisée du FGF10 pourrait induire des dilatations kystiques des voies aériennes.L'objectif de ce travail était de déterminer les anomalies moléculaires à l'origine des MAKP.Dans une approche molécule candidate, nous avons comparé par immunohistochimie l'expression du FGF10, de son récepteur le FGFR2b, et d'un de ses inhibiteurs, Sonic Hedgehog (SHH), entre MAKP et tissus témoins. Nous avons également comparé l'expression de l'ARNm du FGF10 dans des cultures de fibroblastes isolés à partir de MAKP et de tissus témoins. Nous avons enfin élaboré un modèle de ligature trachéale in-utéro de lapins fœtaux, afin de modéliser les MAKP et d'étudier in-vivo en fin de gestation (J29/31) les conséquences morphologiques et moléculaires d'une obstruction trachéale précoce (J23/31). Dans une approche sans à-priori, nous avons microdissequé des MAKP et des tissus témoins, afin de séparer les compartiments épithélial et mésenchymateux et de comparer les transcriptomes issus de ces 2 compartiments entre MAKP et tissus sains. Nous avons également recherché l'existence d'anomalies génétiques in-situ, en comparant par CGH array le génome du tissu pathologique à celui obtenu à partir du sang périphérique provenant du même patient.Aucune différence d'expression du FGF10, du FGFR2b et de SHH n'était observée en immunohistochimie, entre MAKP et témoins. L'expression ARNm du FGF10 était cependant plus élevée dans les fibroblastes de MAKP que dans les fibroblastes de tissus témoins. Nous n'avons pas observé de dilatation des voies aériennes de conduction chez les fœtus ligaturés, mais une augmentation du nombre des alvéoles pulmonaires. La voie de signalisation FGF10 n'était pas surexprimée à J29 dans le poumon des fœtus ligaturés. Les premiers résultats de l'analyse CGH array ne montrent pas de différence entre le génome provenant de la lésion et le génome provenant du sang périphérique. L'analyse transcriptomique est en cours.Il semble donc que la voie du FGF10 ne soit pas surexprimée dans les MAKP, mais il est possible que la surexpression de ce facteur soit transitoire, et que notre analyse ait été trop tardive. L'occlusion trachéale précoce n'affecte pas les voies aériennes de conduction, notre modèle animal n'est pas un modèle de MAKP. Un modèle fondé sur une occlusion bronchique précoce, sur des explants de poumon fœtal serait probablement plus adapté à l'étude des MAKP. L'absence d'anomalie génétique confirme l'hypothèse d'une anomalie localisée et transitoire du développement pulmonaire à l'origine des MAKP

Na construção do discurso ainda incipiente de Timor Leste, Ruy Cinatti e Luis Cardoso são autores fundamentais. Ambos constroem discursos sobre Timor, calcados na necessidade de se pensar as questões identitárias. Com seu caráter multifacetado, Cinatti apresenta uma visão bastante ampla dos timorenses e de seu território, através de sua obra poética e também dos seus inúmeros estudos científicos sobre o local e seus habitantes. Cinatti é, sem dúvida, um dos poucos poetas que articulam ciência e poesia, inaugurando uma nova visão de Timor. É fundamental perceber também como houve, para ele, uma evolução na imagem do timorense, ou seja, como ele deixa de ser um simples elemento exótico, numa paisagem por si só já exótica, e passa a figurar como elemento de destaque. Durante os diversos períodos em que esteve no território timorense, Ruy Cinatti escreveu diversos estudos científicos, além das poesias. A análise de alguns desses documentos complementa a leitura da obra poética do autor. As inúmeras fotos tiradas por ele, bem como os registros em filme, também são elementos fundamentais para a compreensão global do discurso cinattiano acerca de Timor. Ruy Cinatti, assim como o conjunto da sua obra, influenciou o romancista timorense Luís Cardoso, que lança mão da memória para narrar acontecimentos pessoais, sempre ligados a fatos históricos do Timor. Utiliza-se constantemente da memória não-oficial para recuperar a história que não foi registrada. Sua narrativa tem fortes características da literatura oral, com pinceladas de realismo fantástico. O presente trabalho procura traçar um paralelo entre esses dois autores, mostrando como cada um constrói a sua própria imagem de Timor, e perceber como Timor se vai desenhando na narrativa desses dois autores.
In the construction of the still incipient discourse on East Timor, Ruy Cinatti and Luis Cardoso are fundamentally important authors. Both build discourses about Timor based on the need to think about questions of identity. With his multifarious character, Cinatti presents a broad overview of the Timorese and their territory, through his poetic work and also through his countless scientific studies about the place and its inhabitants. Cinatti is, beyond doubt, one of the few poets to articulate science and poetry, introducing a new vision of Timor. It is also crucial to perceive how there was, in his case, an evolution in the image of the East Timorese, or, in other words, how he ceases to be a simple exotic element, in a landscape in itself exotic, and then appears as an outstanding element. During the several periods he spent in the territory of East Timor, Ruy Cinatti wrote many scientific studies, in addition to poetry. The analysis of some of these documents complements the reading of the authors poetry. The countless photos he took, as well as records on film, are also crucial elements in an overall understanding of Cinattis discourse about Timor. Ruy Cinatti, as well as all of his work, influenced the Timorese novelist Luís Cardoso, who makes use of memory to narrate personal events, always linked to historical facts about Timor. He constantly uses the unofficial memory to retrieve the history that was not recorded. His narrative has strong features of oral literature, with touches of fantastic realism. The present work searches to draw a parallel between these two authors, showing how each builds his own image of Timor, and to understand how Timor is pictured in the narrative of these two authors.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This essay has got the goal to study the modernization of the urban environment from the interventions done by public power. This kind of interventions are the changes made on architecture and infrastructure -water channeling, sewer systems, electric power, streets and avenues (construction)-. The chosen place for this research is Sao Luís Northeastern Brazil, Maranhão State capital city- from 1889 to 1970. Sao Luis had a late insertion in the capitals market. It was when Brazil was still a Portuguese cologne, not so modern like another countries. It was necessary to exert despotism in Lusitanian lands for an economic structuring finally to appear and the city s scenery could be changed. This growth led to the first modernization of the urban environmental movement. The building of some sobrados two-floor houses- and sidewalks was given then. In the second half of XIX century the economic prosperity led to decadence and a pessimist feeling. At the same time the republican regime is established in the country. This situation provoked the need to forget all those issues related to monarchy. In this way and following the positivist patrons, modernization appeared as a way of transformation. Not only Republic caused this feeling. Changes were given fast in the West. New habitus sprang up and spread quickly. In opposition to some theoreticians thought, modernization did not die out through the years. It was gaining new shapes and necessities. As a matter of fact, modernization appears nowadays in political speeches and practices as the most important way to development. In a first moment, we divided the modernization process of Maranhão capital in three stages but then, having carried our survey out we realized that this did not longer was didactic. Nevertheless, it became more real and necessary. Sao Luís modernization process has got three stages of transformation. The first stage starts in 1889 when laws begin to be more focused in urban environment, organization and beauty and finishes in the late 20 s. The second stage starts in the 30 s and finishes in the late 40 s, when the state begins to interfere with the whole nation. The state then, starts a urban-industrial project. Finally, in the 60 s and 70 s great infrastructure construction works are done in Maranhão capital city, i.e. the bridge on the Anil River, the dam on the Bacanga River and Itaqui Port. These construction works define a style. To conclude, this modernization is established as a public policy or a group of public policies. It is necessary interventions to carry out these policies, which may be structural and / or related to social control.
O presente trabalho tem como objeto de estudo a modernização do espaço urbano, a partir das intervenções realizadas pelo poder público. Compreende-se por intervenções as mudanças na arquitetura e na infraestrutura (canalização de água, sistemas de esgoto, energia elétrica, construção de ruas e avenidas). O espaço pleiteado para realização da investigação é São Luís cidade do Nordeste brasileiro, capital do estado do Maranhão , no tempo transcorrido de 1889 a 1970. São Luís teve uma inserção tardia no mercado de capitais quando o Brasil ainda era colônia de Portugal, comparada com outras localidades do extenso território. Foi preciso o estabelecimento do despotismo em terras lusas para que aqui houvesse uma estruturação econômica, capaz de transformar a cenografia da cidade. O crescimento viabilizou o primeiro movimento de modernização do espaço citadino, com a construção de grandes sobrados, calçamento de ruas etc. Na segunda metade do século XIX, a prosperidade econômica deu lugar à decadência e a um pessimismo que se apoderou do imaginário coletivo. Concomitante a essas mudanças aconteceu à instalação do regime republicano no país e com ele a necessidade de enterrar tudo que lembrasse a monarquia. Dessa maneira, a modernização, nos moldes positivistas, aparece como caminho de mudança. Não só a República trouxe tal sentimento. No Ocidente as transformações aconteciam em velocidades completamente diferentes das habituais, novos habitus foram emergindo e se espalhando rapidamente. Ao contrário, do que foi pensado por alguns teóricos, a modernização não se exauriu com o tempo, apenas foi ganhando novas formas, novas necessidades, significando que discursos políticos e práticas continuam a ter nela o caminho pleno para o desenvolvimento. Dividimos o processo de modernização da capital maranhense em três momentos. O primeiro período inicia-se em 1889 (quando a legislação passa a problematizar enfaticamente o espaço urbano no sentido de dotá-lo de beleza e organização) e encerra no final dos anos 20. O segundo momento inicia-se na década de 30 e vai até o final dos anos 40, quando o Estado passa a interferir mais decisivamente na totalidade da nação, adotando um projeto urbano-industrial. E por último, focamos nossa investigação na década de 60 e 70, momento em que a capital maranhense recebe obras de grande infraestrutura que redefinem sobremaneira o seu espaço, a citar a construção da ponte sobre o Rio Anil, a barragem do Bacanga e o porto do Itaqui.

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The objective of this dissertation is to understand the intellectual output of Luis Palacin the light of political and intellectual history. Related to the theme of power and ideology, and as a source of research works: Four times Ideology and Subversion and Corruption. The reflection of these works will enable to realize that Louis Palacin as a historicist sought to use other methodologies during your writing to characterize the relations of power in society Goias. The following work provides an understanding of power relations in society Goias, light, thought of Louis Palacin, Spanish historian, who came to Goiania to undertake a project of evangelization but also a serious research project on the history Goiás His works have characteristic of the new political history, breaking with the traditional historiographical thought. Palacin can be considered one of the pioneers in research on power and ideology in Goiás.
O objetivo desta dissertação é compreender a produção intelectual de Luís Palacin à luz da história política e intelectual. Relacionado com a temática de poder e ideologia, tendo como fonte de pesquisa as obras: Quatro tempos de Ideologia e Subversão e Corrupção. A reflexão destas obras possibilitará perceber que Luís Palacin como um historicista procurou utilizar outras metodologias durante a sua escrita para caracterizar as relações de poder na sociedade goiana. O seguinte trabalho proporcionara uma compreensão sobre as relações de poder na sociedade goiana, luz, do pensamento de Luís Palacin, historiador espanhol, que veio para Goiânia realizar um projeto de evangelização, mas também um projeto de pesquisas serias sobre a História Goiás. Suas obras apresentam característica da nova história política, rompendo com o pensamento historiográfico tradicional. Palacin pode ser considerado um dos pioneiros em pesquisa sobre o poder e ideologia em Goiás.

The purpose of this study was to improve student classroom performance through the use of a detailed chemistry webpage. Students utilized a monthly assignment calendar with links to all classroom materials. Links to additional chemistry resources for review and reinforcement were also available to assist both present as well as absent students in their learning. Results indicate that the treatment increased assessment scores and improved student learning behaviors.

Rese- och turistindustrin är en av världens mest expansiva näringar. Även upplevelseindustrin

är på stark tillväxt. Det kan tyckas att nöjesparken Gröna Lund borde gynnas av detta, men

under de senaste sju åren har antalet besökare till Gröna Lund minskat. Med tanke på den

kraftiga ökningen i turistindustrin vore det lönsamt för Gröna Lund att göra en medveten satsning

på att locka fler turister att besöka nöjesparken.

Det första steget för Gröna Lund, om de vill locka dit fler inresande turister, är att se över sitt

sätt att nå ut till turisterna. En viktig del i detta arbete är att få insikt i hur de inresande turisterna

söker information om sevärdheter, det vill säga hur deras process för informationssökning

fungerar, och därefter arbeta för att anpassa Gröna Lunds marknadsföring utifrån detta.

Syftet med denna uppsats är att undersöka inresande Stockholmsturisters process för informationssökning.

Utifrån denna har vi sedan givit förslag på hur Gröna Lund bör anpassa sin

marknadsföring för att överensstämma med denna sökprocess och därmed nå ut till fler inresande

Stockholmsturister.

Vi har satt samman en modell över turisternas process för informationssökning utifrån modeller

skapade av Blackwell, Miniard och Engel samt Gursoy och McCleary. Vi har dessutom

intervjuat inresande turister på Stockholm Tourist Centre samt turistbyråchefen Stefan Pettersson.

För att få information om Gröna Lunds marknadsföring i dag har vi även intervjuat

Andreas Bergén, marknadsutvecklare på Gröna Lund.

Vår utredning visar att Gröna Lund bör anpassa sin hemsida samt den reklam de gör på turistbyrån

för att bättre överensstämma med turisternas process för informationssökning. För att

uppnå detta föreslår vi bland annat att Gröna Lund bör översätta mer information till andra

språk, hyra en monter på turistbyrån och köpa annonsplats på en hemsida riktad till Stockholmsturister.

Om Gröna Lunds informationskällor når ut till flera turister kan även word-of-mouth

öka som en följd av detta.

Le dieu Sol, personnification de l’astre du jour, est documenté à Rome et en Italie bien avant l’avènement de l’empire. Dieu longtemps secondaire, ce n’est que durant l’Antiquité tardive qu’il gagne en importance, mais jamais au point de supplanter Jupiter et de devenir la divinité suprême. Cette étude a pour but d’offrir une approche renouvelée de l’interprétation de son image, en mettant en valeur la constance de son iconographie, l’uniformité des messages qui lui sont associés, son importance croissante dans l’idéologie politique impériale, et ensuite de les expliquer et de les réintégrer dans une perspective plus globale du IIe au IVe siècle. Cette présente thèse a ainsi pour but d’étudier les représentations du dieu Sol, à la fois personne divine et personnification de l’astre diurne, puis d’en déduire la nature du pouvoir cosmique du dieu, notamment par l’étude des documents dans lesquels il est mis en relation directe ou indirecte avec d’autres divinités, et de mettre en relief la spécificité de l’utilisation de l’image du dieu Sol dans un contexte impérial
The Sun deity was documented in Rome and in Italy well before the advent of the Empire. Considered secondary for a long time, this god’s importance grows only during the late Antiquity.This study aims at offering a renewed approach of its image by emphasizing the constancy of its iconography, the uniformity of the messages associated to it, and its increasing importance in the imperial political ideology which we are to explain and place in a more global perspective from the 2nd to the 4th century.Within this thesis we will study the representations of the Sun deity, as a god and as the personification of the sun. From the analysis of its documented relationship to other divinities we will establish its cosmic power and the particular use of its image in an imperial context

Este trabalho propõe uma aproximação entre a Geografia e a Literatura. De cunho marcadamente interdisciplinar, tem a paisagem como elemento de convergência dessas duas disciplinas. Sob o aspecto geográfico, estudou-se a paisagem urbana de São Paulo e suas transformações em meados do século XX. Notadamente, ressaltaram-se as mudanças da cidade de alvenaria para a cidade de concreto, levando-se em consideração a cidade industrial nascente, e suas influências na morfologia das novas paisagens. Para tanto, foi analisada a obra do escritor e jornalista Luís Martins, assíduo produtor cultural desse período, comprometido com seu tempo e com seu mundo. O gênero crônica, privilegiado neste trabalho, é uma literatura, sobretudo, eficiente na cristalização dos fenômenos que cercam o cotidiano urbano, e uma escrita adequada a captar e a retransmitir percepções paisagísticas genuínas e espontâneas. Para enfrentar a maleabilidade e as polissemias envolvidas nos conceitos que cercam tais paisagens, foi utilizada a análise do discurso. Pelo viés semiótico, as paisagens na obra de Luís Martins foram entendidas como um discurso da paisagem que são fenômenos portadores de intenções, crenças e afetos. São também representações sociais do espaço urbano, paisagens literárias que circularam abundantemente durante décadas pela imprensa paulista, através de inúmeros textos e milhares de pessoas.
This work proposes an approach between Geography and Literature. Basically interdisciplinary, the work presents the landscape as a converging element of these two disciplines. Under the geographical aspect, studies on the urban landscape of São Paulo and its transformations during the twentieth century have been conducted. Special attention has been given to the changes from the city of masonry to the city of concrete, taking into consideration the emerging industrial city and its influences on the new landscapes. For that reason, an analysis has been made of the work of writer and journalist Luís Martins, a regular cultural producer of this period, a man committed to his time and world. The style chronicle, highlighted in this work, is an efficient kind of literature as to the crystallization of the phenomena which surround the urban daily life, and an appropriate form of writing to capture and convey genuine and spontaneous landscape perceptions. In order to face the malleability and polysemy involved in the concepts that surround such landscapes we have used discourse analysis. So, with the use of semiotics, the landscapes in Luís Martins work have been understood as a landscape discourse. They are phenomena which bear intentions, beliefs, and affections. They are also social representations of the urban space; literary landscapes which were abundantly spread for decades by the press in São Paulo, through a number of texts and thousands of people.