Thesis (MTech (Medical Technology))--Cape Technikon, 1992. / The steady state in a tumour rapidly changes with its growth and the subsequent deteriorating blood and nutrient supply. This adaptation in the steady state of the tumour is shown in the increased lactate dehydrogenase and acid phosphatase activity in the tumour during it's growth. These alterations in the tumour metabolism places an increased burden on the body to supply nutrient and to discard the waste products of the tumour. This is demonstrated at the macroscopic level by the decreasing body weight and food intake when the tumour burden increases, and also at the metabolic levels by the responses of certain glycolytic and Cori cycle enzymes. Furthermore three distinct stages were observed in the Cori cycle response to the influence of the tumour namely, a silent or preclinical stage, a hypermetabolic stage and a hypometabolic stage. Although the decreasing body weight cannot be directly linked to the process of gluconeogenesis, the onset of anorexia appeared to coincide with the end of the hypermetabolic stage and the beginning of the hypometabolic stage in gluconeogenesis. This clearly shows that the body's steady state is adversely affected by the presence of the tumour and that the conditions at the metabolic level seem to cause the anorexia. Furthermore, it is well known that the success of cancer therapies depends entirely on the effectiveness of the modality to kill the tumour cell and on the ability' of the host to absorb the damage caused by the modality without being destroyed in the process itself. The second part of this study demonstrates the radioprotective effects of ATP at all levels. It is clear from this work that ATP had a bigger influence in protecting the normal tissue than it had on the tumour tissue. This was demonstrated by the response of acid phosphatase (AP) and glucose-ó-phosphate dehydrogenase (G-6-PDH) in the tumour and testis. Furthermore, it would seem that ATP has a multifactorial interaction with the cell, two possible mechanisms of protection are indicated by these results. The first of these interactions is through the receptors of the cell to stimulate enhanced glycolysis, for higher energy production and thus repair. The second possibility is the interaction of ATP with the receptor of the cell to inhibit the production of free radicals and thus damage, as demonstrated by the response of G-6-PDH and AP.

Pharyngoesophageal (PE) tumours are tumours involving simultaneously the hypopharynx and the cervical oesophagus. The challenge in its surgical management lies in its deep-seated location behind the manubrium bone in the cervicothoracic region, in close proximity to great vessels in the lower neck and superior mediastinum. Classically curative surgery is in the form of total pharyngo-laryngo-oesophagectomy (PLO) and gastric pull-up (GPU) via a three-phase one-stage operation. However PLO and GPU is a major undertaking associated with high operative morbidity and reported in-hospital mortality rates of up to 10%. With a comprehensive preoperative work-up we demonstrated accurate tumour diagnosis and staging, with a 100% negative predictive rate. Together with vigilant postoperative surveillance and compliant follow-up, incidence of synchronous and metachronous tumours were low at 11.9% and 1.7% respectively. Manubrial resection (MR) provided access to PE tumours in the cervicothoracic region enabling resection under direct vision with adequate resection margins - pharyngo-laryngo-cervico-oesophagectomy (PLCO). The trachea was resected and re-sited as a mediastinal tracheostoma in case of posterior tracheal wall invasion. Paratracheal and paraoesophageal lymph node dissection was performed in case of nodal metastasis. MR provided ample space for reconstruction of the resultant defect. Furthermore, it enabled access to vessels in the superior mediastinum to support microvascular tissue transfer. Intra-thoracic volume changes on maximal inspiration and expiration measured using computed tomography scan did not show significant difference pre- and post- MR. With attention to operative details, MR proved to be safe with minimal functional disturbance. Free jejunal (FJ) flap was the preferred reconstructive modality as it offered the lowest pharyngocutaneous fistula and anastomotic stricture rates, and donor site morbidities. All patients resumed unrestricted oral diet postoperation. Videofluoroscopic swallowing studies (VFSS) and high resolution manometry (HRM) demonstrated significantly prolonged transit times for all bolus consistencies compared with normal subjects due to asynchronous contractions between the FJ and the oesophageal remnant, presence of retrograde propulsion and residue accumulation within the FJ. However, patients reported significant improvement in swallowing outcomes and associated quality of life (QOL) compared with preoperation (65.3% vs. 42.7%, p=0.02). Majority of patients were able to speak conveniently with a modality of their choice. MR, PLCO and FJ flap showed significantly lower operative morbidities (58.3% vs. 85.7%, p=0.05), shorter hospital stay (42.5 vs. 50.7 days, p=0.37), and lower in-hospital mortality (8.3% vs. 9.5%, p=0.52) compared with PLO and GPU. None required intensive care unit postoperation. In resecting less, oncological outcomes and survival were not inferior to PLO and GPU. FJ patients were able to resume oral diet sooner than GPU with a higher functional oral intake scale (FOIS) at 6 months (100.0% vs. 92.8%). Shorter transit times for all bolus consistencies were demonstrated in VFSS and HRM of GPU patients due to the lack of contractions within the gastric tube. Swallowing, speech and associated QOL outcomes were comparable between the 2 groups. In conclusion, MR, PLCO and FJ flap should be adopted in the surgical management of patients with isolated PE tumours. / published_or_final_version / Surgery / Master / Master of Surgery

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 110-120). Available also in a digital version from Dissertation Abstracts.

published_or_final_version / Medicine / Master / Master of Medical Sciences

Thesis (M.Med.Sc.)--University of Western Australia, 2006.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (p. 172-190).

Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 1997. / Vita. Includes bibliographical references (leaves 78-87).

Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Computing Science. Title from pdf file main screen (viewed on June 13, 2010). Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2006. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2009 Apr 14