Echocardiographic features of the complications of infective endocarditis, with special reference to patients with HIV.

Thesis (M.Med.)-University of KwaZulu-Natal, 2008.Purpose: The aim was to determine the echocardiographic features of patients with infective endocarditis, and to compare the findings in HIV positive versus HIV negative patients. Methods: This was a prospective study, conducted over three years using the modified Duke criteria in diagnoses. A control group of age-matched patients with clinical and echocardiographic evidence of valvular regurgitation, who did not satisfy the criteria and who underwent surgery was used in comparison. Results: During this period 91 patients were screened for infective endocarditis. 77 satisfied the criteria for a definite diagnosis of IE. Blood cultures were positive in 46% cases. The commonest organism was S. aureus. Most patients had advanced valve disruption with heart failure and a high peri-operative mortality. The clinical features in the two groups of patients was similar. The incidence of echocardiographic complications was 50.6% in the whole group. Except for leaflet aneurysms in four HIV positive cases, complications were not more frequent in this group. Conclusion: There was a high rate of culture negative cases in this study, probably related to prior antibiotic usage; in this setting the modified Duke criteria have diagnostic limitations. There was no difference in the clinical presentation of infective endocarditis between HIV positive and HIV negative patients. Leaflet aneurysms were more common in the HIV positive patients

PDAS as workplace tools for science teachers

This paper reports on work in progress on a project investigating the use of personal digital assistants (PDAs) to help students make use of knowledge gained during the study of a Masters course in science education in their professional practice. We report on a review of the literature on mobile technologies as learning tools in workplace settings. We analyse this literature to suggest possible hypotheses for our study. We also describe the selection and design of activities for use on the PDAs, the evaluation strategy based on an activity theory augmented approach for the project and the issues arising during the project

Pasteur\u27s legacy featured at UM shows, lecture

AIMS: Left atrial (LA) volume is an important predictor of morbidity and mortality in cardiovascular disease. Left atrial strain is a feasible technique for assessing LA function. The EchoNoRMAL study recently highlighted the possibility that ethnic-based differences may exist in LA size. There is a paucity of data regarding LA parameters in an African population. We sought to establish normative values for LA volumetric and strain parameters in a black population. METHODS AND RESULTS: This cross-sectional study comprised 120 individuals between 18 and 70 years of age. Left atrial volumes were measured by biplane Simpson\u27s method, and strain parameters were measured using Philips QLAB 9 (Amsterdam, The Netherlands) speckle-tracking software. The mean age was 38.7 ± 12.8 years (50% male). Maximum LA volume indexed (LAVi), pre-atrial LAVi, and minimum LAVi were 19.7 ± 5.9, 12.2 ± 4.4, and 7.7 ± 3.2 mL/m(2), respectively. Females had a higher LAVi compared with males (20.9 ± 6.3 vs. 18.6 ± 5.3 mL/m(2), P = 0.04). Peak global longitudinal strain in the reservoir phase (ɛR) was 39.0 ± 8.3%, and the peak LA strain in the contractile phase (ɛCT) was -2.7 ± 2.5%. No gender differences were noted in ɛR. Body surface area, age, and weight were the main determinants of ɛR on multivariate linear regression analysis. CONCLUSION: The data reported in this study establish the normal reference values for phasic LA volumes and strain in a normal black population and serve as a platform for future studies

Accommodating Dynamic Oceanographic Processes and Pelagic Biodiversity in Marine Conservation Planning

Pelagic ecosystems support a significant and vital component of the ocean's productivity and biodiversity. They are also heavily exploited and, as a result, are the focus of numerous spatial planning initiatives. Over the past decade, there has been increasing enthusiasm for protected areas as a tool for pelagic conservation, however, few have been implemented. Here we demonstrate an approach to plan protected areas that address the physical and biological dynamics typical of the pelagic realm. Specifically, we provide an example of an approach to planning protected areas that integrates pelagic and benthic conservation in the southern Benguela and Agulhas Bank ecosystems off South Africa. Our aim was to represent species of importance to fisheries and species of conservation concern within protected areas. In addition to representation, we ensured that protected areas were designed to consider pelagic dynamics, characterized from time-series data on key oceanographic processes, together with data on the abundance of small pelagic fishes. We found that, to have the highest likelihood of reaching conservation targets, protected area selection should be based on time-specific data rather than data averaged across time. More generally, we argue that innovative methods are needed to conserve ephemeral and dynamic pelagic biodiversity

ST-segment elevation myocardial infarction heart of Charlotte one-year (STEMI HOC-1) study: a prospective study protocol

Abstract Background ST-segment elevation myocardial infarction (STEMI) is a clinically distinguishable yet lethal sequela of ischaemic heart disease (IHD). In sub-Saharan Africa (SSA), death due to acute STEMI is increasing. In South Africa, there is a paucity of data available on the clinical outcomes of acute STEMI within one year for individuals treated in the public healthcare sector. This study primarily seeks to determine the one-year all-cause mortality rate of acute STEMI. The study also assesses the value of serum cardiac biomarkers of myocardial damage and serum uric acid in predicting all-cause mortality in STEMI. Methods This is a single-centre observational prospective cohort of all consecutive individuals presenting with an acute STEMI to the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) in Johannesburg, South Africa. Research data will be sourced on admission through electronic medical records, blood laboratory results and coronary angiography reports, and at follow-up through periodic telephonic interviews and standardised echocardiograms. At least 355 eligible participants will be continuously followed over one year, and clinical outcomes will be measured 30 days, three months, six months and one year after the index hospitalisation. Discussion This study provides insights into the demographic, risk factors and clinical profiles of individuals with STEMI in South Africa. Its findings may improve the risk stratification, prognostication, and therapeutic management of STEMI patients in our setting. By comparing the clinical outcomes between the different coronary reperfusion strategies, our results may guide clinicians in providing better patient treatment, particularly in sub-Saharan Africa, where access to percutaneous coronary intervention may be limited. Furthermore, the study offers insights into the routine use of baseline serum uric acid as a potential low-cost prognostic biomarker of all-cause mortality in STEMI. Finally, this study’s findings may be of public health significance to local policymakers to aid in reinforcing primary prevention strategies and developing structured referral networks for timely coronary reperfusion of acute STEMI

New Biomarkers and Their Potential Role in Heart Failure Treatment Optimisation—An African Perspective

Heart failure is a clinical syndrome resulting from various cardiovascular diseases of different aetiologies and pathophysiology. These varying pathologies involve several complex mechanisms that lead to the activation of the neurohumoral system, inflammation, angiogenesis, apoptosis, fibrosis, and eventually adverse cardiac remodelling associated with a progressive decline in cardiac function. Once a diagnosis is made, the cardiac function has a gradual decline characterised by multiple hospital admissions. It is therefore imperative to identify patients at different stages of the heart failure continuum to better risk stratify and initiate optimal management strategies. Biomarkers may play a role in the diagnosis, prognostication, and monitoring response to treatment. This review discusses the epidemiology of heart failure and biomarkers commonly used in clinical practice such as natriuretic peptides and cardiac troponins. In addition, we provide a brief overview of novel biomarkers and genetic coding and non-coding biomarkers used in the management of patients with heart failure. We also discuss barriers that hinder the clinical application of novel biomarkers. Finally, we appraise the value of polygenic risk scoring, focusing on sub-Saharan Africa

Investigating mobile science learning in workplace settings

The potential of technological developments in the form of handheld mobile devices, such as personal digital assistants (PDAs) to augment and improve the experience of science for the learner has been well documented (see, e.g. Scanlon et al., 2005), as has their use to augment and improve performance in workplace settings (Waycott and Kulkulska-Hume, 2003; Waycott et al., 2003). These devices also have the potential to provide new ways for teachers and learners to engage with mixed media science learning materials. Working with the Open University’s Practice-based Professional Learning (PBPL) Centre for Excellence in Teaching and Learning (CETL), we will address these questions by investigating how science teachers studying the Masters-level course Contemporary issues in science learning use mobile technologies in their workplace settings. In particular, we hope to better understand the ways in which PDAs influence the use of OU course material in workplace contexts, and investigate how the link between knowledge about science communication, education and practice can be influenced by the use of PDAs. In this paper we will report on the first phase of the project, documenting the experiences of revising existing mixed media materials for use on PDAs, and the development and trialling of familiarisation activities and data collection techniques. We used a range of data collection methods to record student and tutor use of the PDAs, including weekly audio diaries and a web-based surveying infrastructure that can be programmed to automatically invite users to submit online questionnaires as they complete course-related activities on their PDAs. The results of the first phase will iteratively be developed to document the use of these materials in workplace settings. Our evaluation is based on the activity theory approach developed by Scanlon and Issroff (2005) and the tool appropriation model developed by Waycott et al. (2003). References Scanlon, E., Jones, A. and Waycott, J. (2005). Mobile technologies: prospects for their use in learning in informal science settings, Journal of Interactive Media in Education 21(5), pp. 1-17. Scanlon, E. and Issroff, K. (2005). Activity Theory and Higher Education: evaluating learning technologies, Journal of Computers and Learning, 21 (6), pp. 430-439. Waycott, J. and Kukulska-Hulme, A. (2003). Students’ experiences with PDAs for reading course materials, Personal and Ubiquitous Computing 7(1), pp. 30-43. Waycott, J., Scanlon, E. and Jones, A. (2003). Using PDAs as learning and workplace tools: An Activity theory perspective. In S. Anastopoulu, M. Sharples and G. Vavoula (Eds.), M-Learn 2002: European Workshop on Mobile and Contextual Learning, Birmingham, England

Effects of age on left atrial volume and strain parameters using echocardiography in a normal black population.

OBJECTIVE: Normal cut-off values for left atrial (LA) size and function may be altered by aging and ethnic differences. No age-related reference values for LA volumetric measurements or LA strain exist in Africans. We aimed to establish normal age-appropriate values of LA size and function in black Africans. Additionally, we studied the correlation between age, LA strain and volumetric parameters. METHODS: In this prospective, cross-sectional study of 120 individuals (mean age 38.7 ± 12.8 years, 50% men), subjects were classified into four age groups: 18-29, 30-39, 40-49 and 50-70 years. LA volumes were measured by biplane Simpson\u27s method, and Philips QLAB 9 (Amsterdam, The Netherlands) speckle-tracking software was used to measure LA peak strain in the reservoir (ƐR) and contractile phase (ƐCT). RESULTS: No significant differences in the maximum and minimum LAVi were noted among the four age categories (P = 0.1, P = 0.2). LA volumetric function assessment showed no difference in reservoir function between age groups (P \u3e 0.05), conduit function decreased with advancing age (r = -0.3, P \u3c 0.001) and booster function displayed a significant increase with age (LA active emptying volume index, P = 0.001). There was a significant decrease in LA ƐR (P \u3c 0.0001) in the older age groups, whereas ƐCT remained unchanged (P = 0.27). CONCLUSION: Age-related changes in LA reservoir, conduit and contractile function in black Africans are similar to those observed in other populations, as was the trend of declining ƐR with advancing age. The preservation of ƐCT with increasing age requires further analysis