published_or_final_version / Medicine / Master / Doctor of Medicine

published_or_final_version / Pharmacology and Pharmacy / Doctoral / Doctor of Philosophy

Hong Kong's aging population has, increased demand for vascular services. Currently, vascular surgery is subsumed under general surgery. The workload on both general surgery and vascular surgery is demanding and hence, not conductive to the development of vascular surgery. The volume of surgery, particularly emergency surgery provided by the Hospital Authority units varies significantly. The collaboration and differentiation of labor at present is not well defined in many centers. This may lead to unnecessary competition and duplication of resources in the long run. This project examined if there is room for improvement in the present situation and provides evidence for relevant service reconfiguration and discusses how Hong Kong can learn from some overseas examples to enhance quality of services delivered to patients. / published_or_final_version / Public Health / Master / Master of Public Health

published_or_final_version / Surgery / Master / Master of Surgery

published_or_final_version / abstract / toc / Pharmacology / Master / Master of Philosophy

published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

The arterioles of the cat sartorius muscle dilate when arterial pressure is reduced. It has been suggested that this dilation is due to a decrease in blood flow which in turn decreases oxygen delivery and increases tissue production of vasodilator substances. The latter diffuse into the vicinity of the arterioles and cause vascular relaxation. This vascular dilation acts to maintain blood flow through the tissue near the control level at a time when perfusion pressure is reduced. This phenomenon, called autoregulation of blood flow, has been observed in most organs of the body. In the following experiments, we attempted to test the hypothesis that a fall in the oxygen level of the tissue is responsible for blood flow autoregulation. We did this by studying the response of cat sartorius arterioles to arterial pressure reduction under conditions where the muscle was supplied with oxygen from the environment in addition to that normally supplied by the blood. Tissue PO₂ was altered by placing the isolated, auto-perfused cat sartorius muscle in contact with silicone fluid equilibrated with a 0% to 20% oxygen gas mixture. As oxygen tension in the bathing fluid was increased, the preponderant response was a decrease in arteriolar diameter, blood velocity and arteriolar volume flow. To illustrate, 8% of the arterioles constricted by an average of 10% and 18% when the muscle was exposed to oxygen tensions of 66 and 132 mmHg, respectively. When blood flow autoregulation was investigated, it was found that elevated oxygen tension in the bathing fluid abolished any significant arteriolar dilation or flow autoregulation in the majority of arterioles studied. In addition, the elevated oxygen environment caused complete cessation of blood flow in many of the smaller arterioles (< 15μ in diameter). The results of this study strongly suggest that the O₂ level of the tissue is an important determinant in local blood flow regulation.

No description available.

No description available.

Venous leg ulceration (VLU) affects roughly 0.6 percent of the western population, with the management of this condition in Australia alone accounting for between AUD$554 and AUD$655 million in health care expenditure every year. Apart from these financial implications, VLU is also associated with a number of adverse psychosocial effects, including depression, anxiety, social isolation, impaired mobility and reduced working capacity. Whilst compression therapy remains the primary treatment of choice for VLU, discomfort, poor compliance and potentially serious complications demand that a more convenient, safer and efficacious treatment of venous ulceration be developed. A herbal extract proposed to advance venous ulcer healing through its venotonic, anti-inflammatory, anti-oedema, anti-enzymatic and anti-exudative properties is Horsechestnut Seed Extract (HCSE). / Thesis (PhDNursing)--University of South Australia, 2005.