A dissertation on a study presented to the Discipline of Speech Pathology and Audiology , School of Human and Community Development , Faculty of Humanities , University of the Witwatersrand , In fulfilment of the requirements for the degree M.A. Audiology , March 2017 / In health care, there appears to be greater consideration for the biopsychosocial model of disability and viewing disability in terms of functional health. Recently, the effect of impairment on the significant other’s (SO’s) quality of life (QOL) has been explored. In audiology, there appear to be very few published studies in this area, particularly related to vestibular disorders. The purpose of this study was to investigate the experiences of vestibular disorders on the SO’s QOL. A qualitative research design was employed, including 11 interviews and two focus groups. Participants were SO’s of individuals with chronic vestibular disorders, and were recruited from a private audiology practice in Gauteng through purposive sampling strategies. Data were analysed using thematic analysis. Eight primary themes emerged in the data analysis: social implications, financial implications, searching for a diagnosis, emotional effects, changes in family dynamics, support systems, comparison-oriented coping mechanisms, and referrals for psychological services. Findings suggested that SO’s experienced third-party vestibular disability; however, having the appropriate support systems, including family and friends, was pertinent. It was also indicated that the relationship with the audiologist was essential in providing better understanding of the condition and prognosis thereof, resulting in less frustration and improved adaptation to the reported changes. A key finding was the lack of referral for psychological or counselling services. These findings suggest the need to account for third-party vestibular disability in clinical, theoretical, and academic settings, and they call for the inclusion of third-party disability in policy-making. / MT 2018

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy / Background Silicosis rates in gold miners in South Africa are very high but there have been no analyses of long term trends. While much research has been conducted on occupational respiratory disease in gold, asbestos and coal miners, little is known about the respiratory health of miners of other commodities, such as diamonds and platinum, two of the most important minerals in South Africa. The ore bodies from which minerals are mined often contain other „incidental‟ minerals and compounds that may cause disease. Aims The aims of this thesis were to conduct the first ever analysis of silicosis trends in black and white gold miners over a 33-year period; to discuss the role of oscillating migration in the high rates of silicosis; and to explore the potential for workers in the diamond and platinum mining sectors to develop occupational respiratory diseases. Methods Gold, diamond and platinum mine workers were identified from the PATHAUT autopsy database at the National Institute for Occupational Health. Trends in silicosis from 1975 to 2007 were calculated separately for black and white gold miners because of differences in exposure, patterns of employment and autopsy referral patterns. The role of oscillating migration in the silicosis epidemic was explored. Diamond mine workers with asbestos-related diseases at autopsy and platinum mine workers with silicosis and/or fibrotic nodules in the lymph nodes were identified. Supplementary data from other sources were reviewed to viii exclude all those who might have been exposed to asbestos or silica, respectively, outside of the mining sector in which they worked. Asbestos lung burdens were calculated for the case series of diamond miners and mine tailings and soil samples were examined for asbestos fibres, using scanning electron microscopy. Findings The proportion of white miners with silicosis increased by 17% (from 18% to 22%) over the 33-year study period. That of black miners increased 10-fold (from 3% to 32%), primarily due to the aging workforce and increasing periods of employment. Adjusted odds ratios for silicosis increased with year of autopsy for black miners. Oscillating migration has also played a major role in the silicosis epidemic. Evidence indicates that diamond mine workers are at risk for developing asbestosrelated diseases and that platinum mine workers are at risk for developing silicosis. Conclusion The gold mines have failed to control silica dust levels adequately and prevent disease in mine workers. The sparsity of available dust measurements and poorly documented work histories are major obstacles to conducting occupational health research in South Africa; attention and legislation needs to be focused urgently on these areas. The PATHAUT database is the only occupational respiratory disease database in South Africa that can be used for disease surveillance, trend analyses and research in all mining sectors.

A research report submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Medicine in Nuclear Medicine. / Forty (40) female patients with breast masses underwent Technetium 99m Sestamibi scintigraphy in order to evaluate its usefulness in differentiating benign from malignant breast disease and to compare scintigraphy to mammography. Informed consent was obtained from each patient. Scintigraphy consisted of anterior chest and lateral and oblique breast planar images, obtained 5 minutes after intravenous injection of 20 rnecuries (740 MBq) Technetium 99m Sestamibi. Eleven (11) of the 40 patients also had Technetium 99m Methylene Diphosponate breast scintigraphy for comparison. Four nuclear medicine physicians of who three also graded the MDP images performed grading of the Sestamibi scintigraphic images. The grading method, although focussing on the absence (0) or presence (>0) of uptake of isotope, was also designed for comparison of the Sestamibi and MDP images. Statistical analysis showed good correlation between observer grading. Breast scintigraphy was compared to mammography in 27 ofthe 40 patients. Of the 26 malignant breast masses confirmed on histology, 19 were positively identified on Sestamibi scanning giving a sensitivity of 73%, 2 results were inconclusive (grading (0·1) and 5 had a grading 0, of the 8 patients with confirmed lymph node metastases, only 2 were positive on the Sestamibi scans, with 1 inconclusive result. Of the 19 benign breast masses, 9 were visible on Sestamibi scans with additional 3 inconclusive results (grading of 0-1). Statistical analysis showed no significant difference in the Sestamibi and MDP grading. In comparison to mammography, breast scintigraphy was less accurate in distinguishing benign from malignant breast masses. Mammography identified 85.7% of the malignant breast masses and 72.7% of the benign breast masses. Sestamibi scintigraphy identified 76.2% of the malignant breast masses and only 36.4% of the benign breast masses. / Andrew Chakane 2018

A Thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg for the Degree of Doctor of Philosophy / Greening is a severe disease of citrus and is a major cause of crop loss in many parts of Africa and Asia.Numerous attempts have been made by various workers to isolate the aetiological agent of the disease and although reports claiming the successful culture of the organism have appeared, the isolations were never fully confirmed. ( Abbreviation abstract ) / AC2017

Dragon (RGMb) is one of the three repulsive guidance molecule (RGM) family members RGMa, RGMb (Dragon) and RGMc (hemojuvelin). RGM family members are glycophosphatidylinositol (GPI)-anchored membrane proteins. The three RGM proteins have been identified as co-receptors that enhance BMP-Smad signaling. Previous studies showed that Dragon protein is expressed in the epithelial cells of kidney tubules including collecting ducts, distal convoluted tubules and thick ascending limbs, and that Dragon enhances BMP4 signaling in tubular epithelial cells. However, the biological roles of Dragon in the renal epithelial cells are yet to be defined. / We now showed that overexpression of Dragon inhibited E-Cadherin expression, but did not affect epithelial-to-mesenchymal transition (EMT) induced by TGF-β1 in mouse inner medullary collecting duct (IMCD3) cells. Dragon also increased cell death induced by hypoxia in association with increased cleaved PARP and cleaved Caspase-3 levels in IMCD3 cells. Dragon did not have any effect on the expression of inflammatory factors in IMCD3 cells. Previous studies suggest that the three RGM members can also function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-Cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. / Dragon expression in the kidney was upregulated by unilateral ureteral obstruction (UUO) in mice. Compared with wild-type mice, heterozygous Dragon knockout mice exhibited 45-66% reduction in Dragon mRNA expression, decreased epithelial cell apoptosis, increased tubular E-Cadherin expression, and had attenuated tubular injury after UUO. UUO-induced renal fibrosis and inflammation did not change between wild-type mice and heterozygous Dragon knockout mice. Similar results were obtained in the model of ischemia-reperfusion kidney injury. Compared with wild-type mice, heterozygous Dragon knockout mice showed decreased epithelial cell apoptosis. Ischemia-induced renal fibrosis and inflammation did not change between wild-type mice and heterozygous Dragon knockout mice. / Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial cell apoptosis both in vitro and in vivo. / Dragon (又稱排斥導向分子b) 是排斥導向分子家族中的一員。這個家族包括排斥導向分子a，排斥導向分子b (又稱Dragon) 和排斥導向分子c (又稱血幼素) 三名成員。它們都是一種磷脂酰肌醇(GPI) 錨定蛋白。研究發現，這三種排斥導向分子都可以作為輔助受體來加強骨形成蛋白信號通路。我們之前的研究發現，Dragon在集合管、遠曲小管和髓袢升支粗段的上皮細胞內都有表達，同時Dragon增強腎小管上皮細胞中骨形成蛋白(BMP)4的信號轉導。但是，Dragon在腎小管上皮細胞中的生物學功能尚不清楚。 / 我們的研究結果表明，Dragon過量表達后降低腎內髓集合管上皮細胞中上皮型鈣粘素 (E-Cadherin) 的表達，但是不影響轉化生長因子-β1誘導的上皮細胞向間充質細胞的轉化。在低氧的條件下，Dragon促進腎內髓集合管上皮細胞的死亡并同時增加活化的多聚二磷酸腺苷酸核糖聚合酶（PARP）和半胱天冬酶3 (Caspase-3) 的量。但是Dragon對腎內髓集合管上皮細胞分泌的免疫因子沒有影響。之前的研究表明，neogenin是這三個導向排斥分子的受體。同樣在我們的研究中發現，Dragon是通過neogenin受體而不是骨形成蛋白信號通路來影響腎內髓集合管上皮細胞的死亡和E-Cadherin的表達。 / 單側輸尿管結扎手術后，在受損傷的小鼠腎臟中Dragon的表達升高。與野生型的小鼠相比，雜合型Dragon敲除小鼠中Dragon信使核糖核酸的表達下降了45-66%，腎小管上皮細胞的凋亡減少，腎小管E-Cadherin的表達升高。單側輸尿管結扎手術后野生型和雜合型Dragon敲除小鼠腎臟皆存在纖維化和炎症，但是二者沒有差異。缺血再灌注的小鼠模型實驗中得到相似的結果。與野生型的小鼠相比，雜合子Dragon敲除小鼠中腎小管上皮細胞凋亡的數目減少。同樣缺血再灌注手術后野生型和雜合子Dragon敲除小鼠腎臟都也存在纖維化和炎症，但二者沒有差異。 / 體內和體外實驗结果均表明，在腎臟損傷過程中Dragon可能損害腎小管上皮的完整性并促進腎小管上皮細胞的凋亡。 / Liu, Wenjing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 192-212). / Abstracts also in Chinese. / Title from PDF title page (viewed on 03, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

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Dissertation submitted to the Faculty of Health Sciences of the University of the Witwatersrand, Johannesburg in fulfilment of the requirement for the degree of Master of Science in Medicine. Johannesburg 23 April 2015 / Knowledge of the anatomical variation in the carotid arterial system is important in understanding the pathogenesis and surgical treatment of atheroma. Thus, this study investigated the anatomical variation of the carotid arterial system and the frequency of atheroma within a South African population. The carotid arterial systems were exposed bilaterally in 77 adult cadavers using standard dissection. The level of the carotid bifurcation, position and curving of the carotid arteries and frequency of common trunks and atheroma were recorded. In addition, the lengths and diameters of the carotid arteries and branches as well as the bifurcation angle were measured. Data was analyzed using descriptive and inferential statistics. The carotid bifurcation most commonly occurred at the C3-C4 intervertebral disc. White males had longer common carotid arteries than white females. The lengths of the internal and external carotid arteries were longer in white males compared to black males. There was a higher frequency of curving of the carotid arteries in white females compared to white males. The thyro-lingual trunk was the most common trunk within the sample. The internal carotid artery was postero-lateral to the external carotid artery within most individuals. In addition, atheroma was observed at the carotid bifurcation in all individuals. The level of the carotid bifurcation, positioning, length and diameter of the carotid arteries in the South African population are similar to descriptions in anatomical texts. The differences found within the study may be attributable to the age of the sample as well as the embryological development of the carotid arteries within the South African population. These variations may influence blood flow within the carotid arteries. Thus, knowledge of these variations may aid in understanding the aetiology and the surgical treatment of atheroma.

Over the last 60 years, grass tetany has been recognised as a significant lethal condition in sheep and cattle.Outcomes from this study include documentation of the likely precursors to grass tetany, ways to recognise these precursors, and long term practices that will enable producers to minimise livestock deaths. The benefit of this research to beef producers is that the environmental circumstances thought to be associated with outbreaks of grass tetany have been identified, along with remedial action that can be taken to prevent deaths occurring.Recommendations to industry on best practice to be adopted by leading producers to minimise outbreaks of grass tetany are made.This study provides an alternate strategy for the management of grass tetany in beef cattle, to the more clinical approaches previously recommended. It is suggested that losses from this economically important metabolic disease can be minimised if management practices of beef cattle producers in eastern Australia can incorporate a more holistic approach to farm management, which takes account of the soil/plant/animal/climate inter-relationships. / Master of Science (Hons)

Bibliography: leaves 227-248.