Thesis (DTech (Biomedical Technology)) -- Cape Technikon, 2002 / Research into the role of homocyst(e)ine in cellular functions was stimulated by homocystinuria, a severe autosomal recessive disorder caused by, in the classic case, deficiency of cystathionine β-synthase. Patients with homocystinuria have plasma homocyst(e)ine levels ten times that of reference values. This study was initiated with the presentation and investigation of a local family with clinical symptoms typical of that found in patients with homocystinuria. The free plasma homocystine level detected in the index case was 12 times higher and the plasma methionine level was a 1000 times higher than the respective normal reference ranges. The most common cause of homocystinuria worldwide is a defect in the cystathionine β-synthase enzyme. Methodology was developed to measure cystathionine β-synthase activity in fibroblast cultures obtained from skin biopsies from the extended family. A radioactive method followed by separation of the amino acids on an amino acid analyzer was used. Both the symptomatic siblings had cystathionine β-synthase enzyme activities <1% of the reference value, which was similar to activities found in known homozygotes for cystathionine β-synthase deficiency. Cystathionine β-synthase enzyme activity in the asymptomatic mother was in the lower half of the reference range while the father had cystathionine β-synthase enzyme activity well below the reference range at less than 10% of activity found in healthy individuals. On the basis of clinical symptoms and above parameters, homocystinuria due to cystathionine β-synthase deficiency was onfirmed.

Masters of Technology: Radiography in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology 2015 / Introduction: Diabetes mellitus is a chronic disease with a significant impact on personal lifestyle and wellbeing. It is associated with a high prevalence of myocardial disease, the early detection of which is important for prevention of disease progression. Although echocardiography is recognised as a leading cardiovascular imaging modality, there has been limited work on its role in the early detection of diabetes-related myocardial dysfunction. The aim of this study was therefore to evaluate the role of echocardiography in the early detection of diabetes-related myocardial disease, in a population with a high prevalence of type 2 diabetes mellitus. Methodology: A single sonographer, blinded to individual biochemical markers conducted detailed echocardiographic examinations on 407 participants from a Cape Town community with a high prevalence of diabetes mellitus. Participants were subsequently stratified by biochemical status, as normoglyceamia or hyperglycaemia. The echocardiographic features of the two groups were compared using the Pearson chi-squared and Mann-Whitney U tests. Findings: Hyperglycaemia was associated with left atrium (LA) enlargement (p ˂ 0.0014), aortic enlargement (p ˂ 0.0067) and inter-ventricular septal (IVS) thickening (p ˂ 0.0001). Conclusion: The findings suggest that echocardiography can be a useful screening tool for myocardial dysfunction in Type 2 diabetes mellitus.

Until recently, the major portion of the study of the electrical activity of the heart has been done with the aid of electrocardiograms and vectorcardiograms. However, such information as the variation of the magnitude and angle of the heart vector with time is not directly discernible from either of these recordings. A polarcardiograph was developed by W.K.R. Park to present the plane projection of the heart vector in magnitude and angle as a continuous function of time. The polarcardiograph proved to be useful but it was not sufficiently stable. An electronic device which would be stable and at the same-time present the heart vector in three dimensions, magnitude, frontal angle and polar angle as continuous functions of time, would be useful in electrocardiographic research. The design of such a computer, the "spherical polarcardiograph", is described in this thesis. The spherical polarcardiograph, which must compute the spherical polar coordinates of points from their respective Cartesian coordinates, has been developed using analog multipliers, subtracters and adders as well as a two-phase sinusoidal voltage source and a device for generating a voltage proportional to the phase difference of two sinusoidal signals. With the exception of the third coordinate computation and the gated feedback circuitry, the system is similar to that used by Park. Automatic balancing of the circuit occurs for a short interval during the rest period of the heart. The spherical polarcardiograph has not been constructed in final form but tests on the individual units indicate that the instrument will be well within the accuracy required for normal electrocardiographic purposes. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Studies carried out in a number of countries have revealed statistically significant negative correlations between death rates from cardiovascular disease (CVD) or ischaemic heart disease (IHD), and the hardness of local water supplies, a phenomenon which is known as the "water story". These findings have not, however, been universal and it was decided that a study carried out in South Africa with its high CVD and IHD death rates, might yield meaningful results to contradict or support existing findings. In 1983 a pilot study was thus initiated using a spatial model and a more detailed study began in 1984. This study ultimately involved the correlation of standardized mortality ratios (SMRs) for CVD and IHD with total water hardness and with a number of contributory and associated water quality factors. The study supported the hypothesised "water story", showing the existence of negative correlations between standardized mortality ratios (SMRs) for both CVD and IHD, and the hardness of potable water, whether measured as total hardness or as its two major contributory cations, calcium and magnesium. The level of statistical significance at which this correlation occurred, however, varied with differences in methodological approach. A "population-unweighted" methodology, which was applied to enable comparison with a number of previously published studies, pointed to potassium (a known hypertension normalisor) in permanently hard water as being an important factor. Problems inherent to each methodological approach have been discussed as has the need for improved data. In this regard, the need for a National water quality data bank has been emphasised.

published_or_final_version / Nursing Studies / Master / Master of Nursing

The purpose of this dissertation series was to describe sedentary behavior and its associations with cardiovascular disease (CVD) biomarkers and outcomes, and to explore the potential that reducing sedentary behavior may be a secondary prevention target for Acute Coronary Syndrome (ACS) survivors. As such, the following series of research studies evaluate the mechanisms, patterns, and correlates of sedentary behavior in relation to CVD risk and examine whether sedentary behavior might be a risk factor for CVD outcomes among ACS survivors. In Chapter II, a cross-sectional study of young, healthy adults examined a set of biomarkers representing several aspects of endothelial cell health to elucidate the relationship between free-living, habitual sedentary time and endothelial dysfunction. Results showed that there were no differences in measures of endothelial cell injury, endothelial cell reparative capacity, or upper extremity endothelium-dependent vasodilatation in participants with high compared with low volumes of device-measured sedentary behavior in a sample of young, healthy adults. These findings suggest that physiological mechanisms other than endothelial dysfunction may need to be explored as a potential link between habitual prolonged sedentary time and CVD in young adults. Chapter III employed group-based trajectory modeling to identify distinct patterns of sedentary behavior, as measured by accelerometry, in ACS survivors over the 28 consecutive days following hospital discharge, and, secondly, to explore potential correlates of these patterns. Results demonstrated that ACS patients as a group engaged in high volumes of accelerometer-measured sedentary time. Three patterns of sedentary behavior over the first month post-discharge were identified; these involved either gradual or rapid reductions in sedentary behavior. Several measures of disease severity and physical health (e.g., GRACE CVD risk score, physical health-related quality of life), and partner status (i.e., married or partnered or without partner), were associated with the worst patterns of sedentary behavior (i.e., high volume of sedentary time with only a slight decline over time). These findings provide insight on the different patterns of sedentary behavior that emerge as patients resume their daily life over the first month post hospital discharge. Chapter IV, building upon the study presented in Chapter III, examined whether accelerometer-measured sedentary behavior of ACS survivors over the first month post hospital discharge was associated with 1-year health outcomes. The purpose of this study was to understand whether sedentary behavior in the early post hospital discharge period may be an important risk factor in ACS survivors, that might be targeted in secondary prevention strategies. Results demonstrated that the average sedentary behavior over the first month post hospital discharge was not significantly associated with increased risk of 1-year recurrent major adverse cardiovascular events or hospitalizations. These findings do not support sedentary behavior in the early post hospital discharge period as a prognostic risk factor that should be modified in ACS survivors as part of secondary heart disease prevention strategy. However, studies with larger sample sizes, and that evaluate sedentary behavior patterns beyond the first month are needed. Collectively, these studies show that high volumes of sedentary behavior are prevalent in ACS survivors over the first month immediately following hospital discharge. Future work is needed to further study the underlying mechanisms through which sedentary behavior may confer CVD risk and to determine whether sedentary behavior is an important modifiable risk factor in ACS survivors.

Thesis (M.Sc. (Chemical Pathology) --University of Limpopo, 2013 / Cardiovascular diseases (CVDs) are among one of the well documented conditions and pose a significant health burden in the world as they areconsidered to be of adult onset. However, recent studies have shown that in developed countries CVD risk factors are becoming prevalent in young people which isof great concern. Therefore, the aim of this study was to determine if CVD risk factors are present in young subjects aged 15-20 years of age residing in a rural area of a developing country. Methods: Subjects aged between 15-20 years who participated in the “Gene - Environment interaction project” were included in this sub-study. Total cholesterol, triglycerides, HDL-cholesterol, LDLcholesterol, insulin, glucose, creatinine, Lp(a), apoB, apoA-1 and hs-CRPwere determined. Blood pressure, physical activity (number of steps/day), weight, height, waist circumference and hip circumference were obtained from the database. Subjects with CRP levels above 10mg/L and creatinine levels above 130 mmol/L were excluded. Results: The present study showed an overall high prevalence of some CVD risk factors. There was high prevalence of insulin resistance (23.0% in females and 34.7% in males), and high hs-CRP (18.4% in females, 12.9% in males). The prevalence of low HDL-C levels was high (55.2% in females and 16.8 % in males), however, the prevalence of abnormal levels of other lipids such as total cholesterol/HDL-cholesterol ratio was low in both males and females. The prevalence of an increased apoB/apoA ratio was significantly higher in females 26.4% compared to males 7.9%. The prevalence of overweight (12.6%) and obesity (9.2%) was higher in females than in males (overweight 1%, obesity 0 %). The prevalence of hypertension was comparable between the two genders (5.7% in females and 10.9 % in males). Conclusion: The results showed a relatively high prevalence of non-traditional risk factors for cardiovascular diseases in adolescents residing in a rural area, Limpopo Province, while the prevalence of traditional risk factors such as total cholesterol and triglycerides was low.

The purpose of this research study was to examine the nature and scope of nutrition counseling and/or education available to cardiac patients and the role of the Registered Dietitian (RD) in Cardiac Rehab Phase II Programs. One hundred and fifty programs were surveyed in regards to their program and the programs elements in regards to nutrition topics. To our knowledge, this is the first study to systematically examine the nature and scope of nutrition counseling and/or education and the role of the Registered Dietitian in Cardiac Rehab Phase II Programs.The results indicated that almost 75% of the programs surveyed offered nutrition counseling and/or education, regardless of the region examined. Also the majority of the programs were identified to have a Registered Dietitian on staff, but less than half reported a Registered Dietitian employment as full-time. There were also significant differences in regards to nutrition education topics among the regions. The results also uncovered a discrepancy between the perceived importance of having a Registered Dietitian on staff and their role as the primary provider of nutrition counseling and/or education. / Department of Family and Consumer Sciences

The purpose of the present study was to test the theoretical relationship of the concepts of informational support and threat appraisal with a sample of surgical cardiac patients twenty-four hours after discharge from the hospital. These discharged patients were adjusting to the transition of hospital to home environment while still recovering from a life threatening illness. They may need varying informational supports to reduce their threat perception of the magnitude of the illness. A convenience sample of thirty-six surgical cardiac patients was assigned to three groups. The groups received the standard discharge preparation as stated by the hospitals' policy and procedure manual. The experimental group received a supportive and informational telephone call approximately twenty-four hours after discharge. The second group was the placebo group, these participants were given a telephone call at the end of the twenty-four hours to remind them to return the questionnaire. The third group was the control group, received no telephone call and were instructed to complete the questionnaire at the specified time. All groups were instructed at the time of initial contact to complete the questionnaire at approximately the end of the first twenty-four hours after discharge. The placebo group and control group were then pooled for data analysis due to the low return rate of the two groups. The two groups were compared with a t-test. The demographic data compared age and educational level to the perceived level of threat. Reliability of the tool was determined using a Cronbach's Alpha. / School of Nursing

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