Factors which may account for the high frequency of macrovascular disease in diabetics are age, sex, cigarette smoking, hypertension, obesity, lack of exercise, diet, hyperglycaemia, hyperinsulinaeroia, hypercholesterolaemia, hypertriglyceridaemia, low HDL-cholesterol concentration, elevated free fatty acid concentration and enhanced platelet aggregation. Twenty seven (13 men and 14 women) non-insulin-dependent diabetics and thirty eight age, height and weight matched healthy subjects (10 men and 28 women) were studied. None of the subjects were smokers, or hypertensive. No subject had any clinical evidence of peripheral arterial disease, coronary heart disease or cerebrovascular disease. All had apparently normal peripheral pulses and normal ankle/arm blood pressure indices. Methods for determining arterial compliance in the segment between the left subclavian artery and each common femoral artery, and proximal resistance at the common femoral artery and posterior tibial artery, have been reviewed and developed. An appropriate food intake methodology for deriving food indices from food records was developed. Biochemical determinants have been made of glucose tolerance, glycosylated haemoglobin, serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, plasma free fatty acid and insulin. A significant decrease in the arterial compliance, and a significant increase in the arterial proximal resistance at the common femoral artery and posterior tibial artery in non-insulin-dependent diabetics, compared with their healthy controls, have been found. Significant negative correlation between arterial compliance and proximal resistance and, a significant positive correlation between the arterial proximal resistance of common femoral artery and posterior tibial artery were found. Differences between control (healthy subjects) and non-insulin-dependent diabetic groups indicate that preclinical peripheral arterial disease can be recognised even in mild diabetics by non-invasive measurement of arterial compliance or proximal resistance. There were significant and negative correlations between arterial compliance and each of blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid and plasma insulin concentration. There were significant and positive correlations between arterial proximal resistance of common femoral artery and posterior tibial artery and each of blood glucose, glycosylated haemoglobin and plasma free fatty acid concentration. Multivariate analysis to examine each of the biochemical factors Including blood glucose, blood glycosylated haemoglobin (HbAlC), plasma free fatty acid, plasma Insulin and lipids, showed that the factor which most influenced the arterial compliance and the proximal resistance of posterior tibial artery was the glucose level in the fasting state or the glucose response after a glucose load. In addition, the factors which most influenced proximal resistance of the common femoral artery were free fatty acid -level in the fasting state or glucose response after a glucose load. The factors which most influenced arterial compliance were glucose level in men, and the insulin level in the fasting state or the plasma free fatty acid response after a glucose load in women. These findings indicate that blood glucose, plasma free fatty acid and plasma insulin are risk factors for changes in arterial wall characteristic at a stage when no clinical evidence of macrovascular disease is apparent. Arterial compliance was decreased and the proximal resistance of posterior tibial artery was increased in those with a low intake of protective foods compared with those with a high intake whether healthy subjects or non-insulin-dependent diabetics. Arterial compliance was decreased in non-fish eaters compared with the fish eaters whether healthy subjects or non-insulin-dependent diabetics. Proximal resistance of the posterior tibia! artery in non-fish eaters was increased compared with fish eaters in healthy subjects. Overall, food variety, a protective food score consumption and fish consumption emerge as importance determinants of arterial wall characteristics at a stage when no clinical evidence of macrovascular disease is apparent.

Aims and Objectives: To investigate the experience of implant complications and opinions on complications among dentists in private practices in Ontario. Methods: In 2010, a web-based anonymous survey was distributed to 2034 Ontario dentists with valid e-mail addresses. Results: 527 dentists replied to the survey, of which 469 utilized implants. Most complications were preventable. The most important cause of complications was “poor planning”. The most severe complication was “permanent paraesthesia”. Fewer than 5% of patients experienced a complication in 2009. There was little agreement among general dentists, oral surgeons, periodontists, and prosthodontists on the causes of complications, some agreement on preventive strategies to avoid complications, and significant agreement on severity of complications and their preventability. Conclusions: A significant proportion of dentists in Ontario had encountered an implant treatment complication in 2009. Since most complications are preventable, efforts at decreasing their prevalence and severity should be pursued.

Aims and Objectives: To investigate the experience of implant complications and opinions on complications among dentists in private practices in Ontario. Methods: In 2010, a web-based anonymous survey was distributed to 2034 Ontario dentists with valid e-mail addresses. Results: 527 dentists replied to the survey, of which 469 utilized implants. Most complications were preventable. The most important cause of complications was “poor planning”. The most severe complication was “permanent paraesthesia”. Fewer than 5% of patients experienced a complication in 2009. There was little agreement among general dentists, oral surgeons, periodontists, and prosthodontists on the causes of complications, some agreement on preventive strategies to avoid complications, and significant agreement on severity of complications and their preventability. Conclusions: A significant proportion of dentists in Ontario had encountered an implant treatment complication in 2009. Since most complications are preventable, efforts at decreasing their prevalence and severity should be pursued.

published_or_final_version / Pharmacology and Pharmacy / Master / Master of Philosophy

published_or_final_version / Medicine / Master / Master of Medical Sciences

Introduction Total hip arthroplasty is one of the most effective interventions to treat patients with end-stage hip arthritis. Although the outcomes of total hip arthroplasty have already been widely studied and most of the published results are positive, the dominant outcomes measures are focused on implant survivorship, patient mortality and complication rates. Quality of life assessment is regarded as a gold standard for outcomes measurement nowadays and was more frequently adopted in researches. However, in most of the study assessing the quality of life of patients undergoing total hip arthroplasty ignored the importance of quality of sexual life. Moreover, none of them are studying the Chinese population. In order to assess the quality of life of patients holistically, a study that focused on the quality of sexual life among Chinese population undergoing total hip arthroplasty is recommended. The aim of the present study is to investigate the changes in quality of sexual life in young Chinese patients undergoing primary total hip arthroplasty. Methodology The present study is a descriptive survey adopted a retrospective design and was conducted either as a phone interview or interview in person. 118 Patients who have undergone total hip arthroplasty at the Queen Mary Hospital are recruited from March 2012 to June 2012. Questionnaires assessing the pre-operation and post-operation sexual life and quality are administered. 118 subjects participated in the study finally. Results 118 subjects participated in the present study. 35 of them reported to have no sexual life due to reasons other than the condition of their hip and were analyzed separately. 83 of the subjects were included in the analysis of changes in sexual life. Preoperatively 50.6% of subjects reported having severe to extreme sexual difficulty. 64 (78.0%) and 16 (19.5%) subjects reported the cause of sexual difficulty to be joint pain and joint stiffness respectively. 61 (73.5%) subjects believed the condition of their hip caused some degree of distress in the relationship with their partner preoperatively. 83.2% of subjects rated their level of sexual difficulty from minimal to mild after having total hip arthroplasty. 23 (28%) and 47 (57.3%) of subjects reported their post-operation sexual life experience to be better and much better respectively. It is shown that greater joint pain (p<0.001) and stiffness (p=0.003) and lower Harris hip score (p=0.001) are significantly correlate with greater pre-total hip arthroplasty sexual difficulty, while only the range of motion of hip remained to be negatively correlated with sexual difficulty post-operatively (p=0.022). Subjects with ankylosing spondylitis are having significantly greater sexual difficulty than participants with other diagnosis post-operatively (p<0.001). None of the subjects have discussed post-total hip arthroplasty sexual life issue with the health care professional. 24 (28.9%) subjects reported their need of more sexual life related information and the most wanted information is safe position for sexual intercourse (75%). Conclusion Total hip arthroplasty can significantly improve the quality of sexual life experience of Chinese patients. Further studies are necessary to be done in order to obtain more relevant information and modify the current patient routine assessment and education. / published_or_final_version / Orthopaedics and Traumatology / Master / Master of Medical Sciences

Immobility is one of the factors associated with the accumulation of respiratory secretion in mechanically ventilated patients. Placing patients in a semi-recumbent position between 30° and 45° and frequent manual turning in every two hours are the standard ventilator nursing care practice adopted worldwide. However, the prevalence of pulmonary complications remains high. The use of continuous lateral rotation therapy (CLRT) to improve drainage of secretion within the lung and the lower airways was proposed and has been investigated in numerous studies. The purposes of this dissertation are (1) to perform a comprehensive systematic review for a critical appraisal of the current evidence on the use of CLRT to prevent pulmonary complications in mechanically ventilated patients, (2) to develop an evidence-based guideline and to assess the implementation potential, and (3) to develop an implementation and evaluation plan for translating the guideline to an adult intensive care unit (ICU) of a teaching hospital in Hong Kong. In order to identify studies that compared CLRT with the standard care, four electronic databases, including CINAHL Plus, Medline, British Nursing Index and PubMed, were searched. 94 studies were identified and eight of them met the inclusion criteria. These studies included one randomized controlled trial (RCT), two non-randomized controlled clinical trials, one pretest-posttest clinical trial and four retrospective cohort studies. The quality of these reviewed studies was assessed by using the appraisal instruments of the Scottish Intercollegiate Guidelines Network. Four of the reviewed studies were graded as high quality. No major adverse patient outcome was reported. Instead, beneficial patient outcomes that reached statistical significance were consistently reported in the CLRT group. There were reductions in ventilator-associated pneumonia (VAP), atelectasis, duration of mechanical ventilation and length of stay. However, its effect on health care cost and mortality was inconclusive. The implementation potential, in terms of the transferability, feasibility, and the cost-benefit ratio, was considered as high in the target setting. Based on the synthesized finding, a CLRT guideline is developed and is proposed to translate into practice. The implementation plan includes a communication plan with stakeholders and a pilot test. The guideline will be revised after the trial run of the proposed innovation for one and a half months. A full-scale controlled trial using a quasi-experimental design will be conducted. The primary outcome is to evaluate whether there is a reduction in the prevalence of VAP after the use of CLRT. According to previous studies, the use of CLRT can lead to a 49% reduction in VAP. The proposed innovation will be considered as clinical effective when similar observation is obtained. / published_or_final_version / Nursing Studies / Master / Master of Nursing

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by disease flares and damage accrual. The increased longevity allows SLE patients to accrue damage which has retarded their survival improvement since the 1980s. In the first study of this thesis, meta-analyses of observational studies revealed that renal and neuropsychiatric damage has been adversely affecting the survival of lupus patients in the past fifty years. While confirmatory studies are required, targeting at renal and neuropsychiatric involvement early might hopefully further improve the survival of SLE patients. As the survival of SLE patients improves, their psychosocial well-being becomes increasingly important. In the second study, anxiety symptoms were found to be significantly more frequent in lupus patients than those with other common inflammatory rheumatic conditions. Additionally, damage accrual and cumulative glucocorticoids accurately predicted anxiety in SLE patients. Related to neuropsychiatric damage, event-related functional brain imaging in the third study showed that new-onset SLE patients had poorer strategic planning skill that required compensatory cortical recruitment for executing comparable cognitive function as in healthy subjects. Even after sufficient control of SLE, they remained to demonstrate inferior strategic planning skill which necessitated compensatory recruitment of cortical areas to boost their executive function. These findings illustrated that cognitive dysfunction persists even after adequate control of SLE. Early recognition of the prognostically challenging renal, cardiovascular and musculoskeletal damage and their predictors is imperative. The fourth study revealed that failure to achieve complete renal remission 12 months after renal presentation predicted renal damage, irrespective of age and the choice of immunosuppressants. As to whether mycophenolate (MMF) or cyclophosphamide (CYC) is better; by meta-analysis, the fifth study concluded that MMF offers similar efficacy as CYC in inducing renal remission and preventing renal damage. As for the cardiovascular system, endothelial dysfunction exerts its impact very early during atherogenesis. As shown in the sixth study, SLE patients na?ve for cardiovascular disease had significantly poorer endothelial function than demographically and anthropometrically matched healthy controls. Higher serum high-sensitivity C-reactive protein level independently predicted poorer endothelial function in SLE patients. Osteoporotic fracture is a major lupus musculoskeletal damage which occurred in 9% of SLE patients as found in the seventh study. Increasing age and duration of corticosteroid use independently predicted osteoporotic fracture. While hormonal replacement therapy appeared fracture protective, its unfavorable long-term consequences limit its indication for fracture prevention. Mitigating fracture risk before fractures occur is the current management strategy. The eighth study found that the significantly higher FRAX? 10-year risk of major osteoporotic and hip fractures amongst SLE patients na?ve for clinical fracture compared with their demographically and anthropometrically matched healthy counterparts was driven by chronic glucocorticoid use and premature menopause. Modifiable factors including low hip bone mineral density (BMD), cumulative glucocorticoids and higher serum anti-dsDNA level independently predicted higher fracture risks. Finally, the relationship between lumbar bone loss and endothelial dysfunction was hitherto identified. Although potential drivers of this relationship remain to be identified, our findings serve to alert physicians to early atherosclerosis in lupus patients particularly in those with low lumbar BMD. / published_or_final_version / Medicine / Master / Doctor of Medicine

Background: Blood safety is important to blood transfusion. As men who have sex with men (MSM) are considered to have a higher risk of sexually transmitted infections (STIs) compared to the general population, blood donations from MSM may lead to a higher risk of transfusion-transmitted infections (TTIs). For this reason, many countries have established lifelong deferral policies for MSM blood donors since 1980s. Research have been conducted to evaluate the risks and benefits of relaxing MSM deferral policies from lifelong to a finite period, and countries such as the United Kingdom have implemented such relaxation in recent years. Nevertheless, there remains a lack of risk-benefit analyses on this topic in many countries, especially the developing ones. This review can help such countries to reconsider their MSM deferral policies. Objective: The objectives of this review are (i) to review the current deferral policies of blood donation from MSM implemented in major countries and (ii) to review the major determining factors in the risk-benefit analyses of these countries. Method: PubMed, Google Scholar, and China Journal Net were used for literature search. Only literatures with abstract and/or available full text in English or Chinese were included. The PICOS approach was used for study selection, and 37 articles were finally selected. Surveys, cohort studies, cross-sectional studies reviews, and national reports were included in this systematic review. Result: Countries with permanent/indefinite MSM deferral policy include the United States, Canada, France, Mexico, Germany, Norway, Sweden and China (including Hong Kong). Countries with a finite deferral period include New Zealand (5 years), the United Kingdom (12 months), Australia (12 months), Brazil (12 months), Argentina (12 months), Japan (6 months) and South Africa (6 months). Countries without specific deferral criteria for MSM include Spain, Italy, Poland and Russia. The recent relaxation of deferral policies was based on scientific evidence provided by risk-benefit analyses that evaluated the residual risk of TTIs associated with alternative deferral policies. Major determining factors of risk-benefit analyses include the following: 1. epidemiological characteristics that determine the proportion of MSM among HIV-infected patients; 2. screening technologies that have shortened the window period and improved the early detection of STIs; and 3. non-compliance after relaxation, which determines the increasing risk of TTIs. Conclusion: Majority of countries that have recently relaxed their deferral policies for MSM blood donor reduced the deferral period to 12 or 6 months. Most of the risk-benefit analyses found that relaxation of deferral policies for MSM blood donors would lead to a relatively small increase in the risk of TTIs. Policies aimed at lowering the non-compliance may be an effective way to reduce the residual risk of TTIs from MSM blood donors who are within the window period. / published_or_final_version / Public Health / Master / Master of Public Health

Although surgical and transcatheter interventions have significantly improved survival of patients with coarctation of the aorta (CoA) and interrupted aortic arch (IAA), long-term complications including left ventricular (LV) abnormalities and systemic arterial dysfunction remain issues of concern despite successful repair. While new indices of myocardial deformation that reflect diastolic and systolic function in terms of strain, strain rate, and torsion as detected by speckle tracking echocardiography have shown promise in the assessment of LV, left atrial (LA), and right ventricular (RV) mechanics, the understanding of ventricular myocardial deformation after repair of CoA is limited. In this thesis, studies were undertaken to test the hypotheses that LV, LA, and RV myocardial deformation is altered and related to structural and functional arterial alterations in adolescents and young adults late after successful intervention of CoA and IAA, and to explore the LV contractile reserve noninvasively by examining the force-frequency relationship (FFR) in these patients. The LV, LA, and RV mechanics were evaluated with tissue Doppler and speckle tracking echocardiography, while carotid arterial structure and function were determined by radiofrequency-based echocardiographic imaging and oscillometry techniques. Supine bicycle stress exercise testing was used to evaluate the FFR by tracking the changes in LV contractility with increase in heart rate. Patients after CoA and IAA repair had significantly greater carotid arterial stiffness and intima-media thickness when compared with controls. Furthermore, mitral annular systolic and diastolic velocities, LV longitudinal and radial strain and early diastolic strain rates, peak torsion and untwisting velocity, and LA peak positive and total strain, and LA strain rates at ventricular systole, early diastole, and atrial contraction were significantly lower in patients than controls. Increased arterial stiffness and intima-media thickness was associated with worse LV myocardial deformation, while LA total strain and LA strain rate at ventricular early diastole were associated with diastolic annular velocities and strain rates. Multivariate analysis further revealed arterial stiffness as an independent determinant of LA total strain. With regard to dynamic assessment of LV contractile reserve, at submaximal exercise, the systemic blood pressures were significantly greater in patients than controls, while mitral annular systolic and early diastolic velocities remained significantly reduced. The increase in LV myocardial isovolumic acceleration, a relative load independent index of contractility, with increase in heart rate during exercise stress was significantly reduced in patients compared with controls. Flattening of FFR in patients reflected impaired LV contractile reserve, which was found to be associated negatively with increment in systemic blood pressure during exercise. For RV mechanics, patients with CoA repaired exhibited significantly lower tricuspid annular systolic and early diastolic velocities, global RV systolic longitudinal strain, and strain rate during systole, early and late diastole, compared to controls. Impairment of RV deformation was further related to increased LV mass and RV thickness. In conclusion, these findings suggest arterial dysfunction, impaired LV, RV, and LA mechanics, and reduced LV contractile reserve, in patients late after CoA and IAA repair even in the absence of residual aortic narrowing and implicate abnormal arterial-LV-LA and LV-RV interactions. / published_or_final_version / Paediatrics and Adolescent Medicine / Master / Master of Philosophy