Thesis (DMed (Medicine. Internal Medicine))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Progressive Myoclonic Epilepsies (PME) are characterized by progressive neurological impairment with myoclonus, seizures and dementia. In contradistinction, Familial Adult Myoclonic Epilepsy (FAME) is characterized by a benign course with rare seizures and cortical tremor. Both conditions have neurophysiological features suggestive of a cortical origin for their myoclonus. This dissertation reports on a novel form of PME. Many of those who were affected had no or minimal progression of their illness, low seizure frequency and were cognitively intact, suggestive of non-progressive disorders linked to the FAME loci. The majority of patients had features of cortical myoclonus, with generalized spike and wave discharges on electroencephalography, enlarged evoked potentials, enhanced C reflexes, and evidence of cortical excitability with magnetic stimulation. However, there was evidence of cerebellar dysfunction both pathologically and on imaging. With regard to similar conditions, dentatorubral pallidoluysian atrophy and Unverricht-Lundborg syndrome were excluded by linkage analysis. Similarly, linkage was not present for either the FAME 1 or FAME 2 loci. This syndrome is both clinically and genetically novel, and has a nosology which is difficult to characterize, in which the condition appears to lie on the spectrum between FAME and PME. The dissociation between the pathological and radiological findings which suggest subcortical dysfunction, and the neurophysiological findings of cortical myoclonus is striking. Review of the literature associated with the neurophysiology of related conditions associated with PME and FAME suggests that: 1. The assumption that generalized forms of myoclonic disorders represent multifocal forms of focal cortical discharges is an oversimplification. 2. The dissociation between initial and later components of the evoked potential is less robust than is generally supposed, and that subcortical inputs may affect later components of the evoked potential. 3. In a high proportion of cases the latency from cortical spike discharge to myoclonic jerk obtained with jerk locked averaging is incompatible with a cortical origin for the spike discharge. 4. The proposal that myoclonus is a form of long latency reflex and that myoclonus represents a reflex arising from subclinical sensory input, is unproven. / AFRIKAANSE OPSOMMING: Progressiewe Miokloniese Epilepsie (PME) word gekenmerk deur progressiewe neurologiese agteruitgang met mioklonus, konvulsies en demensie. Daarenteen word Familiële Volwasse Miokloniese Epilepsie (FAME) gekenmerk deur 'n benigne verloop met ongereelde konvulsies en kortikale tremor. Beide entiteite het neurofisiologiese kenmerke suggestief van 'n kortikale oorsprong vir die mioklonus. Hierdie manuskrip beskryf 'n nuwe vorm van PME. Baie van die aangetaste persone toon geen of min agteruitgang van die siekte oor tyd nie, met 'n lae frekwensie van konvulsies en is kognitief intak, wat suggestief is van 'n nie-progressiewe siekte gekoppel aan die FAME loci. Die oorgrote meerderheid van pasiente het kenmerke van kortikale mioklonus gehad, met algemene spits en boog ontladings op elektroensefalografie, hoë amplitude ontlokte potensiale, versterkte C-reflekse, en tekens van kortikale eksiteerbaarheid met magnetiese stimulasie. Met neurobeelding en patologie was daar egter bewyse van serebellêre disfunksie. Soortgelyke toestande, naamlik dentatorubro-pallidoluysiese atrofie en Unverricht-Lundborg sindroom is uitgeskakel deur middel van koppelingsanalise. Koppeling met die FAME1 of FAME2 loci kon ook nie aangetoon word nie. Die sindroom is beide klinies sowel as geneties nuut en het 'n nosologie wat moeilik gekaraktiseer kan word. Dit wil voorkom of die siekte op 'n spektrum lê tussen FAME en PME. Die dissosiasie tussen die patologiese en radiologiese bevindinge, wat suggestief is van subkortikale disfunksie, en die neurofisiologiese bevindinge van kortikale mioklonus is opmerklik. ’n Oorsig van die literatuur in verband met die neurofisiologie van toestande geassosieer met PME en FAME suggesteer die volgende: 1. Die aanname dat algemene vorme van miokloniese toestande multifokale vorme van fokale kortikale ontladings verteenwoordig, is ’n oorvereenvoudiging. 2. Die dissosiasie tussen inisiële en latere komponente van die ontlokte potensiaal is minder robuust as wat algemeen aanvaar word, en subkortikale invoer mag latere komponente van die ontlokte potensiaal beïnvloed. 3. In ’n groot proporsie van gevalle is die latensie van kortikale spits ontlading tot miokloniese ruk, verkry deur “jerk locked averaging”, nie verenigbaar met met ’n kortikale oorsprong vir die spits ontlading nie. 4. Geen bewyse bestaan vir die teorie dat mioklonus ’n vorm van ’n lang latensie refleks is en dat mioklonus ’n refleks is wat ontstaan uit subkliniese sensoriese invoer nie.

Thesis (DMed (Medicine. Internal Medicine))-University of Stellenbosch, 2005. / Mycobacterium tuberculosis (M. tuberculosis) accounts for more adult deaths than any other infectious agents. The present study included 162 patients with tuberculous pericarditis; 50% of the tuberculous pericarditis patients studied were human immunodeficiency virus (HIV) positive, compared to only 4.2% of patients who presented with non-tuberculous pericardial effusions. A steady year-to-year rise in HIV prevalence was observed in this 6-year study. Although the prognosis of pericardial tuberculosis (TB) is excellent with appropriate medical treatment, untreated pericardial TB has a mortality of 80-85%. It is thus important to diagnose tuberculous pericarditis efficiently. Traditionally, the diagnosis of pericardial TB is established by positive mycobacterial culture and/or histological evidence of necrotising granulomatous inflammation of the pericardium. Our study confirmed the insensitivity of pericardial fluid culture and pericardial biopsy in the diagnosis of pericardial TB, and at the time of clinical decision-making, results were usually not available. To overcome these difficulties, we explored various alternative strategies and this resulted in two diagnostic tools, namely a diagnostic rule and a diagnostic algorithm or classification tree. By means of classification and regression tree analysis, we allocated a weighted diagnostic index to each of five independently predictive features (fever, night sweats, weight loss, serum globulin >40 g/L and peripheral blood leukocyte count <10x109/L). A total diagnostic index of 6 or more corresponded to 82-86% sensitivity and 76-87% specificity for a diagnosis of tuberculous pericarditis. When possible, pericardial fluid should be aspirated to determine adenosine deaminase (ADA) levels and pericardial differential leukocyte counts. Fluid should also be sent for Gram stain and culture. The proposed diagnostic classification tree utilises the independently predictive attributes of pericardial adenosine deaminase levels, pericardial fluid lymphocyte/neutrophil ratios, peripheral leukocyte counts and the HIV status. Applying this prediction model to our entire data set of 233 patients resulted in 96% sensitivity and 97% specificity for the correct diagnosis of tuberculous pericarditis. Generally, patients were critically ill at the time of enrolment; 90% of tuberculous pericarditis presented with echocardiographic features of cardiac tamponade. Echoguided percutaneous pericardiocentesis with an indwelling catheter and intermittent daily aspiration was highly effective and safe. It is likely that the combination of this drainage technique and the early initiation of anti-tuberculous chemotherapy contributed to the almost complete absence of constriction in the patients studied, and our data do not support the routine use of adjunctive corticosteroids in patients with tuberculous pericarditis. Tuberculous exudates result from a Th1 mediated immune response characterised by lymphocyte dominance, significantly elevated levels of gamma-interferon (IFN-γ) and undetectable levels of interleukin-4 (IL-4). IFN-γ levels were not influenced by HIV status in spite of the severely diminished pericardial CD4+ lymphocyte counts observed in this study. It is thus likely that in HIV positive patients IFN-γ production is partly maintained by activated CD8+ T cells, which were significantly elevated in HIV positive patients compared to HIV negative tuberculous pericarditis patients. This finding underlines the importance of IFN-γ in the human immune response against M. tuberculosis. We also demonstrated that the presence of ADA in pericardial fluids reflects the activity of the cellular immune response. Both IFN-γ and ADA can be utilised as sensitive and specific diagnostic tools for pericardial TB.

Thesis (PhD (Medicine. Internal Medicine))--Stellenbosch University, 2008. / Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in Western countries, extending from steatosis (FLD) to steatohepatitis (NASH). Differentiation between NASH and nonprogressive NAFLD is difficult on clinical grounds therefore a need exists to identify reliable biomarkers of disease progression. The aims of the study were 1) to describe the disease profile of NAFLD/NASH in South African patients of the Western Cape, 2) to investigate the metabolic derangements associated with this condition, including insulin resistance, lipid abnormalities and liver fibrogenesis, and 3) to assess the possible involvement of candidate genes in relation to the disease phenotype in the patient cohort. A total of 233 patients (73% female) were enrolled in this study, consisting of 69% Cape Coloured, 25% Caucasian, 5% Black and 1% Asian individuals. All subjects were obese or overweight based on the assessment of body mass index (BMI). Screening for NAFLD identified 182 patients (87%) with ultrasonographical evidence of fatty infiltration and/or hepatomegaly. Liver biopsies were performed on patients with persistently abnormal liver functions and/or hepatomegaly. NAFLD was confirmed histologically in 111 patients of whom 36% had NASH and 17% advanced liver fibrosis. None of the Black patients had advanced fibrosis.

Thesis (PhD (Med))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The increase in the prescription and use of glucocorticoids (GCs) to treat various diseases and resulting decrease in bone density and development of osteoporosis is of growing concern. Glucocorticoid-induced osteoporosis (GCIO) is a relatively under-researched disease with the mechanism by which GCs affect bone metabolism not yet fully delineated. This holds especially true for the early events in bone development. The negative effects of GCs are predominantly seen in osteoblasts, the cells responsible for bone formation, in that GCs diminish both the numbers and function of osteoblastic cells. Osteoblast precursor cell proliferation is crucial to ensure the existence of a healthy pool of osteoblastic cells needed to form new bone after bone resorption by osteoclasts. Previously, it was shown that GCs reduce the proliferation of immortalised osteoblastic cell lines. In addition, early immortalised preosteoblasts were more sensitive to GCs than their mature counterparts. However, these cells have corrupted cell cycles; therefore, primitive primary mesenchymal stromal cells (MSCs) were used in this study to examine the effect of GCs on the mitogen-induced proliferation of early osteoblast precursor cells (naïve MSCs and preosteoblasts) using the synthetic GC, dexamethasone (Dex). Mitogenic conditions established for naïve rat mesenchymal stromal cells (rMSCs) indicated that mild (5% FBS) stimulation is sufficient to induce proliferation, whereas a higher FBS concentration (20% FBS) was mitogenic in primary preosteoblasts. It was also found that pharmacological doses of Dex drastically decreased the mitogen-induced proliferation of both naïve rat MSCs (rMSCs) and preosteoblasts. Mitogen-activated protein kinase (MAPK) signalling pathways, such as ERK1/2, govern cell proliferation. GCs have been shown to decrease the activity of ERK1/2, which is associated with decreased proliferation in osteoblastic cells. In the present study, western blot analysis showed that Dex reduced the proliferation-associated shoulder of the ERK1/2 activity profile in both naïve rMSCs and preosteoblasts. Moreover, the ERK1/2 signalling pathway was shown to be essential for mitogen-stimulated growth of naïve rMSCs and preosteoblasts as the MEK1/2 inhibitor, U0126, inhibited mitogen-induced proliferation. Using western blot analysis, it was shown that, after mitogen administration, ERK1/2 activity exhibited a typical proliferation profile, which was blocked by U0126. Protein tyrosine phosphatases (PTPs) dephosphorylate and inactivate ERK1/2. Utilising sodium vanadate, an inhibitor of PTPs, in vitro phosphatase assays revealed that PTP activity was the predominant phosphatase activity present in naïve rMSCs and preosteoblast lysates after concomitant mitogen and Dex stimulation. The mRNA of the dual specificity phosphatase, MKP-1, was rapidly (within 30 minutes) upregulated after mitogen and Dex administration in both naïve rMSCs and preosteoblasts. However, the protein expression pattern of MKP-1 did not correspond to the mRNA induction, suggesting that the MKP-1 protein could be subjected to rapid degradation. These findings suggest that MKP-1 could possibly be involved in the GC regulation of mitogen-induced proliferation of early osteoblast precursor cells, but closer investigation is needed to fully elucidate this role. In addition, the involvement of other PTPs should not be excluded and warrants further investigation. During the course of the present study, it was found that strong mitogenic stimulation with 20% FBS led to oncogene-induced senescence (OIS). Flow cytometry analysis revealed the presence of two populations in naïve rMSCs preparations and DNA content analysis was consistent with that of cells undergoing OIS. These results indicated that the more primitive osteoblast precursor cells (naïve rMSCs) are more responsive to mitogens than their mature counterparts (preosteoblasts). In addition, it was found that the magnitude of ERK1/2 activation was increased in naïve rMSC after strong mitogenic stimulation, indicating that naïve rMSCs are still highly sensitive to stimulation with strong mitogens. In summary, these findings show that Dex decreased the proliferation of naïve rMSCs and preosteoblasts concomitantly with a decrease in ERK1/2 activity. In addition, Dex upregulated MKP-1 mRNA, but the same effect was not seen on the MKP-1 protein levels. Therefore, this suggests that PTP/s other than MKP-1 could be responsible for the inactivation of ERK1/2 by Dex, leading to decreased proliferation in naïve rMSCs and preosteoblasts. Further identification of PTPs that regulate osteoblast precursor cell numbers and function could lead to the elucidation of the mechanism through which GCs act to negatively influence bone density. This will improve our insights into the pathogenesis of GCIO and aid in the identification of therapeutic targets which can be exploited to develop new agents to treat osteoporosis. / AFRIKAANSE OPSOMMING: Die toename in voorskrifte en gebruik van glukokortikoïede (GKs) om verskillende siektes te behandel en die gevolglike afname in been digtheid, is kommerwekkend. Glukokortikoïed geïnduseerde osteoporosis (GKIO) is 'n relatief min genavorste siekte waarvan die meganisme waardeur GKs been-metabolisme affekteer nog nie ten volle ontrafel is nie. Dit is veral waar ten opsigte van die vroeë stadia in beenontwikkeling. Die negatiewe uitwerking van GK's word oorwegend in osteoblaste, die selle wat verantwoordelik is vir beenformasie, waargeneem, waar GKs beide die getalle en funksie van osteoblaste verminder. Osteoblast voorloper-sel proliferasie is belangrik vir die handhawing van 'n gesonde poel osteoblastiese selle wat benodig word om nuwe been te vorm na beenresorpsie deur osteoklaste. Daar is gevind dat GKs proliferasie van verewigde preosteoblastiese sellyne verminder en dat jong verewigde preosteoblaste meer sensitief is vir GKs as hul meer volwasse ekwivalent. Die selle se selsiklusse is egter gekorrupteer en daarom was primitiewe primêre rot mesenkiem stromaselle (rMSCs) in hierde studie gebruik om die effek van GKs op mitogeen-geïnduseerde proliferasie van vroeë osteoblasvoorloperselle (naïwe MSC en preosteoblaste) deur die sintetiese GK, deksametasoon (Dex), te bestudeer. Mitogeniese kondisies vir naïwe rMSCs het getoon dat matige (5% FBS) stimulasie voldoende is om proliferasie te induseer, terwyl 'n hoë FBS konsentrasie (20% FBS) mitogenies was in primêre preosteoblaste. Daar is ook gevind dat farmokolgiese dosisse Dex die mitogeen-geïnduseerde proliferasie van beide naïwe rMSCs en preosteoblaste verminder. Die mitogeen-geïnduseerde protein kinase (MAPK) pad beheer selproliferasie. Die ekstrasellulêre gereguleerde kinase pad (ERK1/2) is voorheen as die hoofpad wat MBA 15.4 and MG 63 proliferasie beheer geïdentifiseer. Daar is gewys dat GKs die aktiwiteit van ERK1/2 verlaag en proliferasie van die selle verminder. In die huidige studie het western blot analise gewys dat Dex die proliferasie geassosieerde skoueraktiwiteit van die ERK1/2 aktiwiteitsprofiel in beide naïwe rMSCs en preosteoblaste verminder. Die noodsaaklike rol van ERK1/2 pad in mitogeen-gestimuleerde groei van die selle is bevestig deur die MEK1/2 inhibitor, U0126, wat die mitogeen-geïnduseerde proliferasie geïnhibeer het. Western blot analise het gewys dat die ERK1/2 aktiwiteit na mitogeen toediening 'n tipiese proliferasie profile toon wat deur U0126 geblokkeer word. Protein tirosien fosfatases (PTPs) defosforileer and inaktiveer ERK1/2. In vitro fosfatase bepalings met natrium vanadaat, 'n inhibitor van PTPs, het bevestig dat PTP die predominante fosfatase akitiwiteit is in naïwe rMSCs en preosteoblaste lisate is na gelyktydige mitogeen en Dex stimulasie. Die mRNA van die dubbele spesifisiteits fosfatase, MKP-1, is vinnig (binne 30 minute) opgereguleer is na mitogeen en Dex toediening in beide naïwe rMSCs en preosteoblaste. Die proteinekspressie van MKP-1 het egter nie met die mRNA ekspressie ooreengestem nie, wat suggereer dat die MKP-1protein blootgestel is aan vinnige degradasie. Hierdie bevindings stel voor dat MKP-1 moontlik 'n rol speel in die GC-regulering van mitogeen-geïnduseerde proliferasie van vroeë osteoblast voorloperselle maar verdere ondersoek is nodig om die rol ten volle te verklaar. Die betrokkenheid van ander PTPs moet egter nie uitgesluit word nie en regverdig verdere studie. Die huidige studie het bevind dat sterk mitogeniese-stimulasie met 20% FBS tot onkogene- geïnduseerde selgroeistilte (senescence) (OIS) lei. Vloeisitometriese analise het die teenwoordigheid van twee afsonderlike populasies getoon in die naïwe rMSCs preparate en die DNA inhoud was verenigbaar met die van selle wat OIS ondergaan. Die bevindinge stel voor dat die meer primatiewe osteoblast voorloperselle (naïwe rMSCs) is meer vatbaar vir mitogene-stimulasie as hul volwasse ekwivalente (preosteoblaste). Ook is gevind dat die mate van ERK1/2 aktivering hoër was in naïwe rMSCs, selfs na sterk mitogeniese stimulasie wat daarop dui dat naïwe rMSCs steeds hoogs sensitifief is vir stimulasie met sterk mitogene. In opsomming, dui die bevindinge dat Dex die proliferasie van naïwe rMSCs en preosteoblaste onderdruk wat met 'n verlaging van ERK1/2 aktiwiteit gepaard gaan. Verder, het Dex, MKP-1 mRNA opgereguleer maar die effek is nie op die proteinvlak waargeneem nie. Dit suggereer dat PTP/s anders as MKP-1 verantwoordelik kan wees vir die Dex inaktivering van ERK1/2 wat die proliferasie van naïwe rMSCs en preosteoblaste onderdruk.

Thesis (PhD)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Although transthoracic ultrasonography is a well established modality, it is still underutilised by chest physicians. The aim of this research project was to investigate the feasibility, diagnostic yield and safety of ultrasound(US)-assisted transthoracic biopsies performed by clinicians in various settings relevant to daily practice of respiratory medicine. We conducted four clinical trials which are summarised below: 1. In a prospective study on the feasibility of US-assisted transthoracic fine needle aspiration (TTFNA) of drowned lung secondary to a proximal mass lesion, a novel indication for US-assisted TTFNA was described. TTFNA passes >20mm from the visceral pleura had a sensitivity of 74.2% and were also more likely to contain malignant cells than more superficial passes. The surprisingly high yield and the fact that no serious complications were observed validated this approach, which may be an alternative to bronchoscopy. 2. In the largest single-centre study on US-assisted TTFNA with rapid on-site evaluation (ROSE) and cutting needle biopsy (CNB) in the setting of superior vena cava (SVC) syndrome ever reported, we were able to accurately diagnose 96% of all patients who presented with an associated mass lesion that abutted or infiltrated the chest wall. No pneumothoraces or major haemorrhage was caused. We also validated the single-session approach, and were able to conclude that US-assisted TTFNA (with ROSE) is the initial investigation of choice in suspected bronchogenic carcinoma, whereas both TTFNA and CNB need to be performed in all other cases. 3. We continued to validate the novel single-session sequential approach in a study on anterosuperior mediastinal masses. US-assisted TTFNA with ROSE was performed on 45 consecutive patients, immediately followed by CNB where a provisional diagnosis of epithelial carcinoma or probable tuberculosis (TB) could not be established. An accurate cytological diagnosis was made in 73.3%, and was more likely to be diagnostic in epithelial carcinoma and TB than all other pathology (p<0.001). CNB yielded a diagnosis in 88.2%. Overall 93.3% of patients were diagnosed by the single-session approach. No pneumothorax or major haemorrhage was observed. 4. In a prospective study, we compared US-assisted Abrams and Tru-Cut needle biopsies with regard to their yield for pleural TB. Pleural biopsy specimens obtained with Abrams needles contained pleural tissue in 91.0% of cases and were diagnostic in 81.8%, whereas Tru-Cut needle biopsy specimens only contained pleural tissue in 78.7% (p=0.015) and were diagnostic in 65.2% (p=0.022). In conclusion, we investigated the feasibility of US-assisted biopsies performed by respiratory physicians in various settings, and consistently found acceptable to very high diagnostic yields with minimal complications. Furthermore, we were able to validate a novel indication for US-assisted TTFNA (US-assisted TTFNA of drowned lung), validate the use of a single-session sequential approach (USassisted TTFNA with ROSE followed by CNB where indicated) in at least two clinical settings (SVC syndrome and anterosuperior mediastinal masses) and we were able to show that US-assisted Abrams needle biopsy is superior to Tru-Cut needles biopsy when histological confirmation of TB pleuritis is required. / AFRIKAANSE OPSOMMING: Alhoewel transtorakale ultrasonografie ‘n gevestigde modaliteit is, word dit onderbenut deur pulmonoloë. Die doel van hierdie navorsingsprojek was om die praktiese uitvoerbaarheid, diagnostiese opbrengs en veiligheid van sonargerigte transtorakale biopsies uitgevoer deur klinici in verskeie situasies relevant tot die alledaagse praktyk te ontleed. Ons het vier kliniese proewe uitgevoer wat hieronder opgesom word: 1. In ‘n prospektiewe studie oor die praktiese uitvoerbaarheid van sonargerigte transtorakale fyn naald aspirasie (TTFNA) van areas van obstruktiewe pneumonitis sekondêr tot proksimale massa letsels, is ‘n nuwe indikasie vir sonargerigte TTFNA beskryf. TTFNA aspirasies wat >20mm van die visserale pleura geneem is, het ‘n sensitiwiteit van 74.2% gehad en was meer geneig om maligne selle op te lewer as meer oppervlakkige aspirasies. Die verbasende hoë diagnostiese sensitiwiteit en afwesigheid van ernstige komplikasies het die praktiese waarde van hierdie benadering bevestig. 2. In die grootste studie nog oor sonargerigte TTFNA met spoedige in-teater evalusies (SITE) en sny-naald biopsie (SNB) in die teenwoordigheid van superior vena cava (SVC) sindroom, kon ons 96% van pasiënte wat presenteer het met ‘n geassosieerde massa letsel wat die borskaswand betrek, akkuraat diagnoseer. Geen pneumotoraks of major bloeding is waargeneem nie. Ons kon ook die praktiese uitvoerbaarheid van ‘n enkelsessie benadering bevestig en kon tot die gevolgtrekking kom dat sonargerigte TTFNA (met SITE) die aanvanklike ondersoek van keuse is waar bronguskarsinoom vermoed word, maar dat beide TTFNA en SNB noodsaaklik is in ander gevalle. 3. Ons het voortgegaan om die waarde van die nuwe enkel-sessie benadering te bevestig in ‘n studie oor antero-superior mediastinale massas. Sonargerigte TTFNA met SITE is uitgevoer op 45 pasiënte en in gevalle waar ‘n voorlopige diagnose van epiteliale karsinoom of waarskynlike tuberkulose (TB) nie bevestig kon word nie, is dit onmiddelik gevolg deur SNB. ‘n Akkurate sitologiese diagnose is gemaak in 73.3% van gevalle en meer algemeen in epiteliale karsinoom en TB as ander patologie (p<001). SNB was diagnosties in 88.2%. In 93.3% kon ‘n diagnose verkry word met die enkel-sessie benadering. Geen pneumotoraks of major bloeding is waargeneem nie. 4. In ‘n prospektiewe studie is sonargerigte Abrams naald en Tru-Cut naald biopsies se opbrengs vir pleurale TB met mekaar vergelyk. Pleurale biopsie monsters wat met ‘n Abrams naalde geneem is, het pleurale weefsel in 91.0% gevalle getoon en was diagnosties in 81.8%, vergeleke met Tru-Cut naalde wat slegs in 87.7% pleurale weefsel opgelewer het (p=0.015) en wat net in in 65.2% diagnosties was (p=0.022). Opsommend het ons die praktiese uitvoerbaarheid van sonargerigte biopsies uitgevoer deur pulmonoloë in veskeie kliniese situasies nagevors, en het deurlopend aanvaarbare tot hoë diagnostiese opbrengste gevind met minimale komplikasies. Verder kon ons ‘n nuwe indikasie vir sonargerigte TTFNA beskryf en evalueer (sonargerigte TTFNA van obstruktiewe pneumonitis); ‘n enkel-sessie sekwensiële benadering se waarde bevestig (sonargerigte TTFNA met SITE, gevolg deur SNB waar aangedui) in ten minste twee kliniese situasies (SVC sindroom en anterosuperior mediastinale massas); en was dit moontlik om te bewys dat UK-geleide Abrams naald biopsies superior tot Tru-cut naald biopsies is in die histologiese bevestiging van TB pleuritis.

Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: BACKGROUND Lymphomas arise in cells of the immune system. They vary widely in cytomorphology, immunophenotype and clinical course as well as response to treatment - all of which are factors that determine prognosis. The substantial geographical differences that exist for Hodgkin and other lymphoproliferative disorders have been previously reported from the Lymphoma Reclassification Project. OBJECTIVE This investigation was in two parts. In the first we tested the hypothesis that, using comparable treatment regimens, outcome from a private academic centre in the Western Cape region of South Africa would be similar to that from the first world. To this end a series of 512 individuals were analysed. In the second tissue samples from these patients where the most common subtype is diffuse large B-cell lymphoma (n=93) randomly receiving either standard combination chemotherapy in the form of the CHOP regimen or the identical program with rituximab which is an anti-CD20 monoclonal antibody were further investigated in cooperation with the University of Nebraska Medical Centre using an immunohistochemistry based method, also known as tissue microarray. PATIENTS AND METHODS In the first cohort consecutive and comprehensive records of patients diagnosed with lymphoma aged 14 years and older seen between October 1998 in July 2006, were scrutinized. After exclusion for a variety of reasons 398 cases suitable for further definitive study remained. In the second group tissue samples from a total of 149 biopsy proven de novo diffuse large Bcell variants could be further evaluated. After additional refinement a total of 93 remained that met all the entry criteria for the study in which 48 received chemotherapy alone and the remaining 45 chemo-immunotherapy. Demographic features were well matched. The initial stratification of these 93 cases, based on phenotyping with immunohistochemistry employing a tissue microarray method, yielded two populations depending on the criteria used. Each of these primary subdivisions was further evaluated for expression of BCL2 and LMO2 both of which are recognised to predict response. Finally, for each variable, clinical characteristics and survival outcome were compared between chemotherapy as a single modality or the same regimen combined with rituximab. STATISTICAL ANALYSIS Overall and event-free survival were calculated as the years from diagnosis to death, loss to follow-up, first progression or relapse respectively. The Kaplan Meier method was used to estimate distribution and the log rank test to compare survival between groups. Patient characteristics for each cohort specified were tested with Chi-squared or Fisher's exact test for small samples. RESULTS In the first part of this study all 398 cases were retrospectively analysed and showed a similar treatment outcome with regards to overall and event-free survival at 36 months when compared to first world reference centers. Adverse factors identified were similar to published experience comprising constitutional symptoms, prior treatment with chemotherapy, intermediate or high-risk scores as defined by the International Prognostic Index, histologic grading and certain anatomical sites of primary tumour. In contrast gender, staging by Rye or Rai classification, retroviral infection and prior treatment with radiotherapy were without effect. In the second part tissue samples from 93 de novo DLBCL, subtyped using an investigational immunohistochemical based Tissue Micro Array (TMA) were contrasted to the approximately corresponding categories as defined either by Hans and associates using a three marker panel into germinal or non-germinal centre subtypes or by Choi and colleagues with two additional antibodies into germinal centre or activated B-cells. Not surprisingly when compared to DNA-based gene expression profiling, as a reference point, concordance was different being 86 as opposed to 93% for the respective algorithms. The rationale for this exercise was to determine relative cost-effectiveness in an affordable but accurate technology that may be applicable to under resourced areas of the globe. Additionally the prognostic marker expression for BCL2 and LMO2 was investigated with regards to treatment outcome. Using the investigational tissue microarray approach the addition of rituximab to standard chemotherapy group did not show any significant improvement on 5 years overall (63% vs 59%, p 0.68) or event-free survival (42% vs 39%, p 0.94). Similarly no differences were evident in subtype analysis. Interestingly however, when segregated on the Choi criteria, cytotoxic drugs alone showed a non-significant trend in improved survival (74% vs 55%, p 0.32) as well as event-free survival (44% vs 40%, p 0.42) for the germinal centre as opposed to the activated B-cell subtype. Nevertheless not even a small difference could be demonstrated in the presence of rituximab. According to Choi, both regimens (chemotherapy with or without the addition of rituximab) revealed similar results to the Hans algorithm on 5 years OS as well as 3 year EFS when comparing GCB versus non-GCB subgroups. BCL2 and LMO2 marker expression of the respective immunohistochemical (IHC) subtype, despite small sample size, revealed the following. Analysis by Choi criteria on survival for BCL2, no matter for which subsets (GCB or ABC) or treatment modality (chemotherapy with or without the addition of rituximab) showed no difference in 5 years OS or EFS. However, in contrast, a significant difference for better EFS (p=0.0015) in the BCL2 positive group of the ABC subgroups subtypes treated with rituximab containing chemotherapy. These results must be interpreted with care due to the very low sample size and the follow up time of only 9 months. For LMO2 similar results on survival outcome were seen thus showing no difference in 5 years OS or EFS – regardless of subtype or treatment modality. Also here, this was contrasted by better EFS (p=0.039) in the LMO2 positive group of ABC subtypes when treated with the rituximab containing regimen. Again the reservation about small numbers and the 14 months observation period apply. DISCUSSION AND CONCLUSION Most of the studies examining the proportions of subtypes in large series of DLBCL patients have been predominantly carried out on Western populations. While 50% of patients in North America or Europe express GCB phenotypes, this is only 31% in their Asian counterparts. Thus far, no study has been published on lymphoma subtypes in South African populations using a Tissue Micro Array (TMA) method. Despite certain limitations of this study, due to a variety of reasons such as loss of analysable data, variability of representation of the South African population as a whole or low sample size leading to a potential source of error, these results confirm that lymphoproliferative disorders are heterogeneous. Neverless this group can be treated successfully if exact staging, classification and risk assessment defines the holistic management plan – no matter if in a developed or under resourced setting. With the introduction of sophisticated methods such as gene expression profiling (GEP), diffuse large B-cell lymphoma (DLBCL) can be classified into the prognostically favourable germinal center B-cell–like (GCB) and the more aggressive activated B-cell–like (ABC) subtypes. Against the background of resource restriction we therefore used an immunohistochemical (IHC) stain method to analyse formalin-fixed, paraffin-embedded tissue samples. Here the algorithm by Choi et al., originally described by Hans et al., showing a high concordance rate, was comparable to the GEP classification. The use of the IHC based TMA methodology was shown to be a simple, cost effective and a robust alternative to GEP which is currently regarded as the gold standard for the classification in lymphomas. It provides a useful prognostic tool in stratifying DLBCL or other entities in future, even when frozen tissue samples are not available for GEP analysis. With the current budgetary limitations in public hospitals chemotherapy protocols for lymphoproliferative disorders exclude agents such as rituximab. Local therapeutic drug committees consider the approximately 15% overall survival benefit seen at 5 years for DLBCL when rituximab is added to combination chemotherapy as too marginal for justifying the arising additional expenses. Accordingly, demonstration that a specific molecular subtype accounts for superior outcome when using these regimens is needed and would provide convincing evidence for the use of this monoclonal antibody in a resource constrained setting. / AFRIKAANSE OPSOMMING: AGTERGROND Limfome ontstaan vanuit selle van die immuunsisteem. Hulle toon ‘n groot verskil met betrekking tot sitomorfologie, immunofenotipe, kliniese verloop, asook respons op behandeling – almal faktore wat prognose bepaal. Die Limfoom Herklassifikasieprojek het getoon dat daar substansiële geografiese verskille bestaan vir Hodgkin se limfoom en ander limfoproliferatiewe toestande. Huidige navorsing oor hierdie maligniteite skep die indruk dat hulle skaars is in Afrika, met die inligting wat wel beskikbaar is hoofsaaklik gebaseer op gevallestudies deur klinici en patoloë. DOEL Hierdie studie bestaan uit twee dele. In die eerste toets ons die hipotese dat die uitkomste vir die behandeling van limfoom in ‘n privaat akademiese instansie geleë in die Wes-Kaap, Suid- Afrika, dieselfde is as wat in die res van die wêreld gesien word indien soortgelyke behandeling toedgedien word.`n Reeks van 512 pasiënte is in die analise gebruik. Vir die tweede hipotese het`n kohort van die mees algemene subtipe, naamlik diffuse groot B-sellimfoom (DLBCL) (n = 93), lukraak òf die standaardkombinasie-chemoterapie in die vorm van CHOP òf `n identiese program met rituximab, `n anti-CD20 monoklonale teenliggaam, gekry. Die teenliggaam is in samewerking met die Universiteit van Nebraska se Mediese Sentrum getoets met behulp van `n immunohistochemies-gebaseerde metode, ook bekend as weefsel mikro-skikking (tissue microarray or TMA). PASIËNTE EN METODE Vir die eerste kohort is die opeenvolgende en volledige rekords van pasiënte wat ouer as 14 was en tussen Oktober 1998 en Julie 2006 in `n privaat-gebaseerde akademiese instansie gediagnoseer is, noukeurig ondersoek. Na sekere uitsluitingskriteria toegepas is, was daar 398 gevalle wat geskik was vir verdere analise. In die tweede deel van die navorsing kon 149 pasiënte wat nuut met diffuse groot B-sel-limfoom (DLBCL) gediagnoseer is, verder geëvalueer word. Drie-en-neëntig van hierdie 149 pasiënte het aan die kriteria vir insluiting voldoen; 48 het slegs die standaard chemoterapie (CHOP) ontvang en die oorblywende 45 het chemo-immunoterapie (chemoterapie plus rituximab (R-CHOP) ontvang. Die demografiese eienskappe van beide groepe het goed vergelyk. Vanweë die kriteria wat gebruik is, het die aanvanklike stratifikasie van 93 gevalle, wat deur middel van die TMA-metode op fenotipering met immunohistochemie gebaseer was, twee populasies gelewer. Hierdie primêre subdivisies is verder geëvalueer vir uitdrukking van BCL2 en LMO2, beide erkende voorspellers van respons. Laastens is kliniese eienskappe en oorlewingsuitkoms ná behandeling met chemoterapie as `n enkel modaliteit of dieselfde chemoterapie met rituximab, vir elke veranderlike met mekaar vergelyk. STATISTIESE ANALISE Algehele en insident-vrye oorlewing is bereken as die jare vanaf diagnose tot sterfte, verdwyning van pasiënte tydens opvolg, eerste progressie of terugval van die toestand. Die Kaplan Meier-metode is gebruik om distribusie te bepaal en die log rank-toets om oorlewing tussen die groepe te vergelyk. Pasiëntkenmerke vir elke gespesifiseerde kohort is met die Chikwadraattoets of Fisher se eksakte toets in die geval van kleiner groepe getoets. RESULTATE In die eerste gedeelte van die studie is al 398 gevalle terugwerkend geanaliseer en daar is gevind dat die behandelingsuitkoms met betrekking tot totale oorlewing en insident-vrye oorlewing teen 36 maande vergelykbaar was met uitkomste in eerstewêreldsentrums. Nadelige faktore met betrekking tot oorlewing was soortgelyk aan reeds gepubliseerde data en het die volgende ingesluit: gestelsimptome, voorafgaande behandeling met chemoterapie, intermediêre of hoë-risiko tellings soos deur die Internasionale Prognostiese Indeks bepaal, histologiese gradering en sekere anatomiese setels van primêre tumor. In teenstelling met internasionale ondervinding het geslag, steiering volgens Rye- of Rai-klassifikasie, retrovirale status en vorige behandeling met radioterapie geen invloed gehad nie. In die tweede gedeelte is weefsel van 93 nuut-gediagnoseerde DLBCL-pasiënte wat deur middel van die TMA-metode subtipeer is, vergelyk met naastenby ooreenstemmende kategorieë soos deur Hans et al. met `n drie-merkerpaneel in kiem- en nie-kiemsentrumsubtipes, of deur Choi et al. met twee bykomende teenliggame in kiemsentrum of geaktiveerde B-selle gedefinieer. Met die DNA-gebaseerde geen-uitdrukkingsprofiel as `n verwysingspunt, was die ooreenstemming tussen die onderskeie algoritmes na verwagting verskillend, met 86% teenoor 93%. Die onderliggende rasionaal was om die relatiewe lonendheid te bepaal van `n bekostigbare maar akkurate tegnologie, wat moontlik in gebiede met onvoldoende hulpbronne toegepas kon word Verder is die prognostiese merkeruitdrukking vir BCL2 en LMO2 ook met die oog op die uitkomste van behandeling ondersoek. In vergelyking met standaard chemoterapie, het die gebruik van die TMA-tegniek met toevoeging van rituximab geen noemenswaardige verbetering in die algehele 5-jaar oorlewing (63% vs 59%, p = 0.68) óf insident-vrye oorlewing (42% vs 39%, p = 0.94) getoon nie. Insgelyks was daar geen duidelike verskille in subtipe-analise nie. Dit is egter interessant dat, met die toepassing van die Choi-kriteria, sitotoksiese middels op hul eie, in teenstelling met die geaktiveerde B-sel-subtipe, nie ‘n statisties belangrike neiging tot beter oorlewing (74% vs 55%, p = 0.32) of insident-vrye oorlewing (44% vs 40%, p = 0.42) vir die kiemsentrumsubtipe (GCB) getoon het nie. Dit was selfs nie eers moontlik om ‘n klein verskil in die teenwoordigheid van rituximab te demonstreer nie. Volgens Choi, het chemoterapie (met óf sonder die toevoeging van rituximab) by vergelyking van kiemsentrumsubtipes met nie-kiemsentrumsubtipes soortgelyke resultate gelewer as die Hans algoritme na 5-jaar oorlewing, sowel as 3-jaar insident-vrye oorlewing. Ten spyte van ’n klein steekproef het verdere subtipe-analise van BCL2- en LMO2- merkeruitdrukking van die onderskeie immunohistochemiese (IHC) subtipes die volgende aan die lig gebring: Analise met gebruik van die Choi-kriteria vir subtipe-analise vir BCL2- uitdrukking het, ongeag die subtipe (GCB of ABC) en die behandelingsmodaliteit (chemoterapie met of sonder toevoeging van rituximab), geen verskil getoon in 5-jaar oorlewing en insident-vrye oorlewing nie. Daar was egter `n noemenswaardige verskil ten opsigte van beter insident-vrye oorlewing (p = 0.0015) in die BCL2-positiewe groep van die ABC-subtipes wat met rituximab-bevattende chemoterapie behandel is. Hierdie resultate moet egter met sorg geïnterpreteer word weens die klein steekproef en kort opvolgperiode van slegs nege maande. Soortgelyke resultate met betrekking tot die uitkoms vir oorlewing is vir LMO2 gelewer, naamlik geen verskil ten opsigte van 5-jaar oorlewing of insident-vrye oorlewing ongeag die subtipe of behandelingsmodaliteit. Hier ook was daar egter beter insident-vrye oorlewing (p = 0.039) in die LMO2-positiewe groep van die ABC-subtipe wanneer rituximab-bevattende chemoterapie toegedien is. Weereens moet die resultate met sorg interpreteer word weens die klein steekproef en die kort opvolgperiode van 14 maande. BESPREKING EN GEVOLGTREKKING Die meeste studies wat reeds die verhoudings van subtipes in groot getalle DLBCL-pasiënte ondersoek het, is onder westerse populasies uitgevoer en daar bestaan onsekerheid oor of dieselfde verhoudings in Afrika van toepassing is. Terwyl 50% van alle DLBCL-pasiënte in Noord-Amerika of Europa die GCB-fenotipe uitdruk, kom dit in slegs 31% van hierdie pasiënte in Asië tot uitdrukking. Geen studie is tot dusver met behulp van die TMA-metode onder limfoomsubtipes in populasies in Afrika onderneem nie, veral nie onder pasiënte met verswakte immuunstelsels nie. Ten spyte van sekere beperkings van hierdie studie, waarvoor daar verskeie redes is, soos die verlies van analiseerbare data, die wisselende verteenwoordiging van die Suid-Afrikaanse bevolking as ‘n geheel en die klein steekproef, wat vergissing in die hand kan werk, bevestig die resultate dat limfoproliferatiewe toestande heterogeen is. Desnieteenstaande kan hierdie groep met sukses behandel word indien ‘n holistiese bestuurplan presies volgens stadiums, klassifikasie en risiko-assessering uitgevoer word – ongeag of dit in `n ontwikkelde gebied of een met min hulpbronne plaasvind. Met die beskikbaarheid van ingewikkelde metodes soos geen-ekspressie profielskepping (GEP), kan DLBCL in prognosties-voordelige kiemsentrum B-sel-agtige (GCB) en die meer aggressiewe geaktiveerde B-sel-subtipes geklassifiseer word. Teen die agtergrond van beperkte hulpbronne, is immunohistochemiese (IHC) kleuringsmetodes gebruik om - weefselmonsters wat in formalien gefikseer en in paraffien ingebed was, te analiseer. Hier was die algoritme wat oorspronklik deur Hans et al. beskryf is en deur Choi et al. verder ontwikkel is, en hoë ooreenstemming toon, vergelykbaar met die GEP-klassifikasie. Die gebruik van die IHC-gebaseerde metodologie is as ‘n eenvoudige, effektief lonende en kragtige alternatief tot GEP, wat tans as die goudstandaard vir klassifikasie van limfoom beskou word, bewys. Dit verskaf ‘n nuttige prognose-hulpmiddel vir die stratifisering van DLBCL of ander entiteite in die toekoms, selfs wanneer gevriesde weefselmonsters nie vir GEP-analise beskikbaar is nie. Onder die huidige begrotingsbeperkings in staatshospitale is middels soos rituximab by die protokolle vir die behandeling van limfoproliferatiewe toestande uitgesluit. Plaaslike terapeutiese middel-komitees beskou die nagenoeg 15% algehele oorlewingsvoordeel teen vyf jaar, wat vir DLBCL moontlik is met die toevoeging van rituximab by kombinasiechemoterapie, as te randstandig om die bykomende onkoste te regverdig. Daarvolgens is dit noodsaaklik om te demonstreer dat `n spesifieke molekulêre subtipe tot ’n beter uitkoms lei wanneer hierdie metode gebruik word en dat dit oortuigende bewyse sal lewer vir die gebruik van hierdie monoklonale teenliggaam in `n omgewing met beperkte hulpbronne.

Thesis (DMed)--Stellenbosch University, 2008. / The comparative study presented in this dissertation specifically aimed to assess fracture risk in black (Xhosa) and white South African women by evaluating known determinants of bone strength as well as the propensity to falls. We thus compared the prevalence of clinical (historic) risk factors for osteoporosis, measured and compared vertebral and femoral bone mineral density (BMD) employing dual energy X-ray absorptiometry (DEXA), ultrasound variables using the Sahara sonometer, serum parathyroid hormone (PTH) and 25-OH Vitamin D, mineral homeostasis and modern biochemical markers of bone turnover, bone geometry and the propensity to falls. Finally, we determined the prevalence of vertebral fractures in these black and white South African females. 1. Significant ethnic differences were noted in the presence and frequency of historical clinical and lifestyle risk factors for osteoporosis. Blacks were heavier and shorter, they consumed less calcium, were more inactive, preferred depot-medroxyprogesterone acetate as contraceptive agent and were of higher parity. Whites smoked more, preferred oral oestrogen containing contraceptive tablets and were more likely to have a positive family history of osteoporosis. Hormone therapy was used almost exclusively by postmenopausal whites. Inter-ethnic differences in weight, physical activity and high parity was most marked in the older subjects. 2. We found that peak spinal BMD was lower, but peak femoral BMD similar or higher (depending on the specific proximal femoral site measured) in black South-African females compared with whites. The lower peak spinal BMD was mainly attributed to lower BMD’s in the subgroup of black females with normal to low body weight, indicating that obesity either protected black females against a low spinal BMD or enhanced optimal attainment of bone mineral. An apparent slower rate of decline in both spinal- and femoral BMD with ageing was noted in the black females compared with whites in this cross-sectional study – an observation which will require confirmation in longitudinal, follow-up studies. This resulted in similar spinal BMD values in postmenopausal blacks and whites, but significantly higher femoral BMD measurements in blacks. The volumetric calculation of bone mineral apparent density (BMAD) at the lumbar spine and femoral neck yielded similar results to that of BMD. Spinal BMAD was similar in blacks and whites and femoral neck BMAD was consistently higher in all the menopausal subgroups studied. Weight significantly correlated with peak- and postmenopausal BMD at all sites in the black and white female cohorts. Greater and better maintained body weight may be partially responsible for slower rates of bone loss observed in black postmenopausal females. Most of the observed ethnic difference in BMD was, in fact, explained by differences in body weight between the two cohorts and not by ethnicity per se. 3. A low body weight and advanced age was identified as by far the most informative individual clinical risk factors for osteopenia in our black and white females, whereas physical inactivity was also identified as an important individual risk factor in blacks only. Risk assessment tools, developed and validated in Asian and European populations, demonstrated poor sensitivity for identification of South African women at increased risk of osteopenia. The osteoporosis risk assessment instrument (ORAI) showed the best results, with sensitivities to identify osteopenic whites at most skeletal sites approaching 80% (78% - 81%). The risk assessment tool scores appear to be inappropriate for our larger sized study cohort, especially our black subjects, thus resulting in incorrect risk stratification and poor test sensitivity. General discriminant analysis identified certain risk factor subsets for combined prediction of osteopenia in blacks and whites. These risk factor subsets were more sensitive to identify osteopenia in blacks at all skeletal sites, compared with the risk assessment tools described in the literature. 4. Higher ultrasonographically measured broadband ultrasound attenuation (BUA) and speed of sound (SOS) values were documented in our elderly blacks compared with whites, even after correction for differences in DEXA determined BMD at the spine and proximal femoral sites. BUA and SOS showed no decline with ageing in blacks, in contrast to an apparent significant deterioration in both parameters in ageing whites. If these quantitative ultrasound (QUS) parameters do measure qualitative properties of bone in our black population, independent of BMD as has been suggested in previous work in Caucasian populations, the higher values documented in elderly blacks imply better preservation of bone quality in ageing blacks compared with whites. The correlation between QUS calcaneal BMD and DEXA measured BMD at the hip and spine was modest at best. QUS calcaneal BMD was therefore unable to predict DEXA measured BMD at clinically important fracture sites in our study population. 5. Bone turnover, as assessed biochemically, was similar in the total pre- and postmenopausal black and white cohorts, but bone turnover rates appeared to differ with ageing between the two racial groups. A lower bone turnover rate was noted in blacks at the time of the menopausal transition and is consistent with the finding of a lower percentage bone loss at femoral sites at this time in blacks compared with whites. Bone turnover only increased in ageing postmenopausal blacks, and this could be ascribed, at least in part, to the observed negative calcium balance and the more pronounced secondary hyperparathyroidism noted in blacks. Deleterious effects of secondary hyperparathyroidism on bone mineral density at the proximal femoral sites were demonstrated in our postmenopausal blacks and contest the idea of an absolute skeletal resistance to the action of PTH in blacks. The increase in bone turnover and the presence of secondary hyperparathyroidism due to a negative calcium balance may thus potentially aggravate bone loss in ageing blacks, especially at proximal femoral sites. 6. Shorter, adult black women have a significantly shorter hip axis length (HAL) than whites. This geometric feature has been documented to protect against hip fracture. The approximately one standard deviation (SD) difference in HAL between our blacks and whites may therefore significantly contribute to the lower hip fracture rate previously reported in South African black females compared with whites. Average vertebral size was, however, smaller in black females and fail to explain the apparent lower vertebral fracture risk previously reported in this population. Racial differences in vertebral dimensions (height, width) and/or other qualitative bone properties as suggested by our QUS data may, however, account for different vertebral fracture rates in white and black women – that is, if such a difference in fact exists. 7. The number of women with a history of falls was similar in our black and white cohorts, and in both ethnic groups the risk of falling increased with age. There is a suggestion that the nature of falls in our black and white postmenopausal females may differ, but this will have to be confirmed in a larger study. Fallers in our postmenopausal study population were more likely to have osteoporosis than non-fallers. Postmenopausal blacks in our study demonstrated poorer outcomes regarding neuromuscular function, Vitamin D status and visual contrast testing and were shown to be more inactive with ageing compared with whites. An increased fall tendency amongst the black females could not however be documented in this small study. Quadriceps weakness and slower reaction time indicated an increased fall risk amongst whites, but were unable to distinguish black female fallers from non-fallers. 8. Vertebral fractures occurred in a similar percentage of postmenopausal blacks (11.5%) and whites (8.1%) in our study. Proximal femoral BMD best identified black and white vertebral fracture cases in this study. Quite a number of other risk factors i.e. physical inactivity, alcohol-intake, poorer physical performance test results and a longer HAL were more frequent in the white fracture cases and could therefore serve as markers of increased fracture risk, although not necessarily implicated in the pathophysiology of OP or falls. However, in blacks, only femoral BMD served as risk factor. Similar risk factors for blacks and whites cannot therefore be assumed and is deserving of further study. White fracture cases did not fall more despite lower 25-OH-Vitamin D, poorer physical performance and lower activity levels than non-fracture cases. Calcaneal ultrasonography and biochemical parameters of bone turnover were similar in fracture and non-fracture cases in both ethnic groups. Our study data on vertebral fractures in this cohort of urbanized blacks thus cautions against the belief that blacks are not at risk of sustaining vertebral compression fractures and emphasize the need for further studies to better define fracture prevalence in the different ethnic populations of South Africa. 9. In our study, hormone therapy in postmenopausal white women improved bone strength parameters and reduced fall risk. In hormone treated whites compared with non-hormone users, a higher BMD at the spine and proximal femur as determined by DEXA were documented and all QUS measurements were also significantly higher. The biochemically determined bone turnover rate, as reflected by serum osteocalcin levels, was lower in hormone users. Fall frequency was lower in the older hormone treated women (≥ 60yrs) and greater quadriceps strength and reduced lateral sway was noted. Only one patient amongst the hormone users (2%) had radiological evidence of vertebral fractures compared with four patients (6%) amongst the never-users. As hormone therapy was used almost exclusively by whites in this study population, the impact of hormone therapy on postmenopausal black study subjects could not be assessed.

Thesis (DMed (Medicine. Internal Medicine))--University of Stellenbosch, 2007. / Background Although great progress has been made in defining genes conferring the majority of genetic risk in Long QT Syndrome (LQTS) patients, there remains a substantial challenge to explain the widely observed variability in disease expression and phenotype severity, even among family members, sharing the same mutation. Identifying clinical and genetic variables capable of influencing/predicting the clinical phenotype of LQTS patients would allow a more accurate risk stratification, important for determining prognosis, selecting patients for the most appropriate therapy, and counseling asymptomatic mutation carriers (MCs). To address these questions an Italian LQT2 family and a South African Founder LQT1 population have been used. Methods and Results Italian LQT2 family. The proband, a 44-yr-old white woman, presented with ventricular fibrillation and cardiac arrest. Intermittent QT prolongation was subsequently observed and LQT2 was diagnosed following the identification of a missense KCNH2 mutation (A1116V). The proband also carried the common KCNH2 polymorphism K897T on the non-mutant allele. Relatives who carried A1116V without K897T were asymptomatic but some exhibited transient mild QTc prolongation suggesting latent disease. Expression studies in Chinese Hamster Ovary (CHO) cells, demonstrated that the presence of KCNH2-K897T is predicted to exaggerate the IKr reduction caused by the A1116V mutation. These data explain why symptomatic LQTS occurred only in the proband carrying both alleles. South African LQT1 population. The study population involved 320 subjects, 166 MCs and 154 non mutation carriers (NMCs). Off ß-blocker therapy, MCs had a wide range of QTc values (406-676 ms) and a QTc>500 ms was associated with increased risk for cardiac events (OR=4.22; 95%CI 1.12-15.80; p=0.033). We also found that MCs with a heart rate <73 bpm were at significantly lower risk (OR=0.23; 95%CI 0.06-0.86; p=0.035). In a subgroup of patients Baroreflex Sensitivity (BRS) was determined both in presence and absence of ß-blocker therapy. BRS, analyzed in subjects in the 2nd and 3rd age quartiles (age 26-47) to avoid the influence of age, was lower among asymptomatic than symptomatic MCs (11.8±3.5 vs 20.1±10.9 ms/mmHg, p<0.05). A BRS in the lower tertile carried a lower risk of cardiac events (OR 0.13, 95%CI 0.02-0.96; p<0.05). This study also unexpectedly determined that KCNQ1-A341V was associated with greater risk than that reported for large databases of LQT1 patients: A341V MCs were more symptomatic by age 40 (79% vs 30%) and became symptomatic earlier (7±4 vs 13±9 years), both p<0.001. Accordingly, functional studies of KCNQ1-A341V in CHO cells with KCNE1, identified a dominant negative effect of the mutation on wild-type channels. Conclusion Our findings indicate that risk stratification for LQTS patients must be more individually tailored and may have to take into account the specific mutation and probably additional clinical and genetic variables capable of influencing/predicting the clinical phenotype of LQTS patients. As a matter of fact, we have provided evidence that a common KCNH2 polymorphism may modify the clinical expression of a latent LQT2 mutation and the availability of an extended kindred with a common mutation allowed us to highlight that KCNQ1-A341V is associated with an unusually severe clinical phenotype and to identify two autonomic markers, HR and BRS, as novel risk factors.

Thesis (PhD (Medicine. Internal medicine))--University of Stellenbosch, 2007. / 1.1. Background Tumors arising from the lung, pleura, or chest wall are a frequent problem in clinical pulmonary medicine. Most lesions are either infectious, neoplastic or granulomatous in nature, but a variety of other differential diagnoses must be considered. An accurate diagnosis is important because the available treatments differ substantially, and because any delay will impair the prognosis in potentially curable patients with lung carcinoma. The investigations involve the disciplines of radiology, pulmonology, surgery, microbiology, and anatomical pathology and consume a respectable amount of resources. The aim of the work covered in this thesis was to optimize the available diagnostic methods for the routine use in a health care setting with limited resources. 1.2. Methods The general idea of this work was to identify conventional sampling methods that could be developed further to become more useful for the diagnosis of chest tumors in a low resource health care setting. The key method was research performed: a) to revise and expand the indication for a sampling method, b) to technically improve the sampling process, and c) to optimize sample transport, preparation and analysis in collaboration with the analytical laboratory. 1.3. Results A list of invasive diagnostic procedures, imaging methods and analytical processes were developed, evaluated and integrated into clinical practice. A) transbronchial needle aspiration, B) transthoracic cutting needle biopsy, C) transthoracic fine needle aspiration, D) transthoracic ultrasound, and E) rapid on-site evaluation of needle aspirates by a cytopathologist. Five studies pertaining to this thesis were published in international peerreviewed journals: â ¢ Safety and yield of ultrasound-assisted transthoracic biopsy performed by pulmonologists (Respiration 2004;71:519-22) This paper established that ultrasound-assisted transthoracic biopsy performed by pulmonologists is feasible, safe, practical, low-cost and has a high yield. â ¢ Utility of rapid on-site evaluation of transbronchial needle aspirates (Respiration 2005;72:182-8) This paper demonstrated the economical advantages of on-site evaluation of transbronchial specimens in a low-resource setting. â ¢ Transbronchial needle aspirates: comparison of two preparation methods (Chest 2005;127:2015-8) This paper demonstrated that preparing smears on-site has a far better yield than pooling samples into a vial. This means that the yield is improved over the current standard at no additional cost. â ¢ Transbronchial needle aspirates: how many passes per target site? (European Respiratory Journal 2007;29:112-6) This paper investigated the most economical and effective approach to serial sampling with transbronchial needle aspiration during flexible bronchoscopy. â ¢ Ultrasound assisted transthoracic biopsy: fine needle aspiration or cutting needle biopsy? (European Respiratory Journal 2007;29:357-62) This paper compared two common methods of sampling and demonstrates that the less expensive method is sufficient in the majority of cases. 1.4. Conclusion This work has impacted on current practice in multiple ways. Conventional methods have been optimized by improving technical factors and with the integration of interdisciplinary collaboration. The initiated research is ongoing with the aim to achieve continued technical and economical improvements in the diagnosis of chest tumors.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Title The Effect of Highly Active Antiretroviral Therapy on Human Papilloma Virus Infection and Cervical Cytological Abnormalities in Women Living With HIV Background Human Papillomavirus (HPV) infection causes cervical cancer. The prevalence of HPV-related dysplastic lesions is significantly higher in patients co-infected with the HI virus and thought to be linked to possible more persistent HPV infection. There is, however, conflicting evidence as to whether treatment of Human Immunodeficiency Virus (HIV) infection with antiretroviral agents may influence cervical HPV infection and the behaviour of Squamous Intraepithelial Lesions (SIL). Aims To examine the effect of the initiation of combination antiretroviral therapy (cART) on: 1) the persistence of cervical Low-grade SIL (LSIL); 2) The progression of cervical LSIL to High-Grade SIL (HSIL); 3) The effectiveness of excision treatment of HSIL 4) HPV genotypes detected, in HIVinfected and uninfected women at the Infectious Diseases Clinic and the Colposcopy Clinic, Tygerberg Teaching Hospital, Cape Town, South Africa. Design and Methods We conducted a retrospective cohort analysis of 1720 women with LSIL of the survival of progression-free-time or time-to-clearance. Time to progression or persistence was compared according to HIV status, antiretroviral treatment and CD4 count. In another retrospective cohort analysis, we investigated the effectiveness of excision treatment in 1848 women who underwent LLETZ or CKC biopsy was used. Logistic regression and survival analysis were used to compare excision treatment failure and recurrence-free time between groups according to HIV status, antiretroviral therapy and CD4 count. To investigate the effect of antiretroviral therapy on the cervical HPV infection, 300 HIV-infected women were prospectively enrolled and followed at 6-monthly interval. Cytological testing and cervical HPV sampling were done at each visit. Biopsy of suspicious lesions and excision treatment were done at colposcopy clinic according to standard a protocol. The Roche Linear array HPV genotyping test was used for HPV detection. Generalized Estimating Equation (GEE) multivariate analysis was applied to investigate the effect of cART on the detection of HPV infection, while adjusting for time-dependent covariates such as CD4 count, sexual activity and excision treatment. The effect on each HPV type was then also compared to the effect on HPV16. Results Overall, we found that there was no difference between the progression of LSIL to HSIL by HIV status. However, among HIV-infected patients, those who started ART before first LSIL had a significantly lower risk for progression (HR 0.66, 95% CI 0.54-0.81). CD4 count did not have an impact on the risk for progression. We also found lower persistence of SIL in the HIV uninfected group (HR 0.69, 95% CI 0.57-0.85) and that cART was independently associated with decreased persistence of LSIL. On the other hand, a higher CD4 count at the time of first LSIL was not associated with lower persistence of the lesion. HIV infected women with HSIL experienced much higher excision treatment failure than uninfected women (53.8% vs. 26.9%, p<0.001). Factors that improved outcome were higher CD4 count and complete excision. cART reduced the risk of detection of any HPV type by 47% (OR 0.53, 95% 0.49-0.58, p<001). When adjusted for covariates, time of exposure to cART and CD4 had a stronger effect. Every month of cART exposure reduced the risk detection of any HPV type with 7%. The effect was also significant on HPV16 alone (OR 0.93, 95% CI 0.90-0.95). All non-oncogenic subtypes were influenced similarly or more strongly than HPV16, as well as oncogenic HPV52. Only one oncogenic subtype HPV subtype, HPV39, was influenced marginally less (ratio of OR 0.95, CI 0.90-0.99, p=0.04). There was an increased risk for any HPV detection at CD4 count<200 (OR 1.63, 95% CI:1.50-1.77), but when adjusted, the time of cART exposure again remained the strongest predictor of risk (OR 0.94, 95% CI:0.93-0.95). Conclusion cART impact the outcome of cervical HPV infection by increasing clearance, decreasing progression of LSIL and recurrence after excision treatment. This effect is time dependent and also associated with CD4 count. Specifically, HPV16 detection risk is also reduced by cART, and all HPV types are influenced at least as much as HPV16, except possibly HPV39. It seems that increased cervical HIVproviral load is associated with HPV detection risk, and both are lowered by cART time. / AFRIKAANSE OPSOMMING: Titel Die Effek van Kombinasie Antiretrovirale Terapie op Menslike Papilloomvirusinfeksie en Servikale Sitologiese Abnormaliteite in Menslike Immuniteitsgebrekvirus-geïnfekteerde Vroue Agtergrond Menslike Papilloomvirusinfeksie (MPV) veroorsaak servikale kanker. Die prevalensie van MPVverwante displastiese letsels is betekenisvol hoër in pasiënte wie ook met Menslike Immuniteitsgebrekvirus (MIV) geïnfekteer is en dit word gereken dat dit te wyte is aan meer persisterende MPV infeksie. Daar is egter teenstrydige bewyse oor of die behandeling van MIV infeksie met antiretrovirale (ART) middels die infeksie met MPV en die gedrag van Plaveisel Intraepiletiële letsels (PIL) kan beïnvloed. Doelwitte Om die effek van die inisiasie van kombinasie ART op: 1) die persistering van Laegraadse PIL (LPIL); 2) die progressie van servikale LPIL na hoëgraadse PIL (HPIL) 3) die sukses van eksisiebehandeling van HPIL; 4) MPV genotypies waarneembaar, in MIV-geïnfekteerde vroue by die Infeksiesiektekliniek en die Kolposkopiekliniek,Tygerberghospitaal, Kaapstad, Suid-Afrika, te ondersoek. Studie-ontwerp en Metodes `n Retrospektiewe kohort-analise op 1720 vroue met LPIL van die oorlewing van progressive-vrye tyd en tyd tot opklaring van PIL is gedoen. Tyd tot progressie of opklaring is vergelyk na aanleiding van die pasiënt se MIV status, behandeling met antiretrovirale terapie en CD4-telling. In nog `n retrospektiewe kohort-analise is die effektiwiteit van eksisiebehandeling in 1848 vroue wie LLETZ or Kouemeskonus eksisie ondergaan het, ondersoek. Logistiese regressie en oorlewingsanalise is toegepas om die voorkoms van onsuksesvolle uitkoms en tyd sonder herhaling van letsels tussen groepe te vergelyk na aanleiding van MIV status, ART en CD4-telling. Om die effek van antiretroviral therapie op servikale MPV infeksie te ondersoek, is 300 MIVgeïnfekteerde vroue opgeneem in `n prospektiewe studie en sesmaandeliks opgevolg. Sitologiese en MPV servikale smere is met elke besoek geneem. Biopsies van verdagte letsels en eksisiebehandeling is by die Kolposkopiekliniek gedoen volgens die standaardpraktyk. Die Roche Linear Array HPV Genotyping toets is gebruik vir MPV deteksie. Algemeen-beraamde vergelyking (GEE) meerveranderlike analise is toegepas om die effek van die anti-MIV terapie op die teenwoordigheid van MPV op die serviks te ondersoek. Die aangepaste effek is ook getoets deur die CD4-telling, die seksuele aktiwiteits- en eksisiebehandelingstatus by elke besoek in ag te neem. Die effek op elke MPV genotipe is laastens dan ook vergelyk met die effek op ‘n spesifieke basislyn genotype; in hierdie geval was MPV16 gekies. Resultate Daar was geen statisties beduidende verskil tussen die progressie van LPIL na HPIL na aanleding van HIV status nie, maar pasiënte wie met ART begin het voordat hulle vir die eerste keer met LPIL gediagnoseer was, het ‘n laer risiko gehad vir progressie (HR 0.66, 95% VI 0.54-0.81). Daar is ook gevind dat dit onafhanklik van die CD4 telling was. Die persistering van PIL was laer in die MIV negatiewe groep (HR 0.69, 95% VI 0.57-0.85), maar ook hier was antiretrovirale behandeling geassosieer met verminderde persistering. Weer eens was daar nie ‘n verband met die CD4 telling nie. MIV-geinfekteerde vroue met HPILwas baie meer geneig tot gefaalde eksisiebehandeling (53.8% teenoor 26.9%, p<0.001). Verbeterde uitkoms was geassosieer met ‘n hoër CD4-telling en ‘n eksisie wat as volledig beskryf was. ART wat reeds voor die eksisiebehandeling begin was, het nie die risiko vir onsuskesvolle uitkoms statisties beduidend verminder nie, maar het egter die risiko vir herhaling van letsels na die eksisie sterk verlaag. ART het die kans dat enige MPV tipe waargeneem sou word, met 47% verlaag (OR 0.53, 95% VI 0.49-0.58, p<001). Wanneer aangepas vir ander faktore, was die tyd wat verloop het sedert ART begin was, sowel as vir die CD4 telling, sterker. Vir elke maand sedert ART begin was, het die kans dat enige MPV tipe waargeneem word, met 7% verminder. `n Soortgelyke effek is op HPV16 alleen gevind (OR 0.93, 95%, VI 0.90-0.95). Die effek was net so sterk of sterker op alle subtipes. Slegs een onkogeniese subtipe, MPV39, was gering minder beïnvloed (ratio van OR 0.95, VI 0.90-0.99, p=0.04). Die kans vir waarneming van enige MPV subtype is hoër wanneer die CD4 telling laer as 200 selle/ɥl is (OR 1.63, 95% VI: 1.50-1.77), maar wanneer aangepas, was die tyd van ART weer eens die sterkste voorspeller van MPV infeksie (OR 0.94, 95% VI:0.93-0.95). Gevolgtrekkings ART verbeter die uitkoms van servikale infeksie met MPV deur progressie en persistering van LPIL en herhaling van PIL na eksisie te verminder. Die effek is tydsafhanklik en word ook deur die CD4 telling beïnvloed. Die kanse dat MPV16 spesifiek waargeneem word, word ook deur ART verminder, en all MPV tipes ondervind dieselfde of groter verlaging van waarnemingsrisiko as MPV16, behalwe miskien MPV39. Ons kon aandui dat verhoogde teenwoordigheid van servikale MIV verband hou met die risiko vir die waarneming van MPV infeksie, en beide word verminer deur die tyd waarmee die pasiënt met ARV terapie behandel is.