The aims of this study were: (i) to determine the association between p53, bcl-2, pRb, p21, cyclin A and p-glycoprotein immunoexpression and prognosis, and (ii) to determine the frequency of loss of heterozygosity and microsatellite instability at 11 p, 16q and mismatch repair gene loci and their association with prognosis, in nephroblastomas in South African children. There were 138 cases (111 of whom received preoperative chemotherapy) in the immunohistochemical study and, 70 cases (48 with preoperative chemotherapy) in the microsatellite study. The following monoclonal antibodies were used after heat induced epitope retrieval; p53, bcl-2, pRb, p21, cyclin A and p-glycoprotein. Six polymorphic microsatellite markers were selected from the 11p region, 5 from the 16q region and 6 from the loci of known mismatch repair genes. Automated fluorescent DNA technology was used in the analysis. The results of the immunohistochemical and microsatellite studies were correlated with patient age, gender, preoperative chemotherapy, SlOP histological classification, SlOP histological risk group, clinicopathological stage, patient outcome and survival using X2 , Fisher's exact test, Cox regression model and Kaplan-Meier estimates. The majority of patients presented with advanced disease. Anaplastic tumours and high-risk histology were associated with high disease stage. Mortality was directly related to increasing stage and histological risk group. Multivariate analysis showed that clinicopathological stage was the only factor significantly associated with survival (p<0.001) (hr=5.6, 95%CI: 2.1-14.9). High expression of p53 was more frequent in anaplastic tumours suggesting that p53 mutations are common events in this tumour type (p<0.001). Despite the strong association with tumour histology, there was no association with stage. Although p53 expression was found to be a predictor of survival in the univariate analysis this was not retained in the multivariate analysis. Tumours treated with preoperative chemotherapy showed higher bcl-2 immunoreactivity (p=0.027 but lower levels of pRb (p=0.040) and cyclin A expression (p<0.001). All anaplastic tumours showed high expression of pRb compared to the other histological types (p=0.003). Expression of xxii pRb was significantly associated with survival in the univariate analysis but not in the multivariate analysis. High cyclin A expression was associated with high risk histology (p<0.001). Cyclin A expression was found to be a significant predictor of survival in both the univariate (hr=1.7; 95%CI 1.2-2.4; p=0.002) and multivariate analyses (hr=1.7; 95%CI1.1-2.7; p=0.032). Although tumours with high risk histology were more likely to express high levels of p-glycoprotein, this did not reach significance. LOH at 11 p was seen in 64.7% of 68 informative cases. LOH at 11 p13 was more frequent than LOH at 11p15. LOH for both 11p13 and 11p15 was found in 39.7% of all tumours. MSI at 11 p was seen in 22.1 % of informative cases. The majority showed MSI for one marker only. LOH 16q was seen in 66.7% of 66 informative cases. MSI at 16q was seen in 16.7% of cases. LOH for 016S496 and 016S520 appear to be related to tumour histology and risk group. The most frequent locus for LOH was 16q21-22, which is known to harbour important genes, such as, E2F4 and E-cadherin. LOH for MMR markers was seen in 43.5% of 69 informative cases. MSI was seen in 11.6% of tumours. In the multivariate analysis there was no significant correlation between LOH at any of the loci studied and survival. There were no tumours with high frequency MSI. Low frequency MSI was of no clinicopathological significance. The following conclusions are made: (i) p53 mutations determined by high p53 expression is a frequent finding in anaplastic tumours, (ii) Bcl-2 may play a role in the chemoresistance of nephroblastomas, (iii) Rb gene alterations are not important in the development of nephroblastoma and anaplasia, (iv) Cyclin A expression is an independent predictor of survival, (v) p-glycoprotein may be responsible for the chemoresistance in a proportion of nephroblastomas, (vi) MSI is a rare occurrence in nephroblastoma and does not play a role in the development of nephroblastoma, (vii) LOH at 11 p and 16q are frequent findings in nephroblastomas, (viii) LOH for the specific 16q markers (016S496 and 016S520) may have an important prognostic role in nephroblastoma. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2008.

Thesis (PhD (Pathology. Anatomical Pathology))--University of Stellenbosch, 2006. / Patients with chronic gastro-oesophageal reflux disease are predisposed to Barrett’s metaplasia and oesophageal adenocarcinoma. The availability of molecular markers that can objectively identify patients with Barrett’s oesophagus at increased risk of carcinoma is highly desirable. A literature search was conducted to identify potentially useful biomarkers for genotype-phenotype correlation studies in South African patients with Barrett’s oesophagus. The COX-2, c-myb and c-myc genes selected for mRNA expression analysis were analysed in 26 patients with Barrett’s metaplasia (BM) without dysplasia; 14 with Barrett’s oesophagus and dysplasia (BD); 2 patients with Barrett’s adenocarcinoma (BAC); 19 with erosive oesophagitis (ERD); 25 with non-erosive oesophagitis (NERD) and 19 control individuals with a normal gastroscopy and no gastro-oesophageal reflux disease (GORD) symptoms. In the BD/BAC group, 69% (11/16) showed increased c-myb mRNA expression compared with 35% (9/26) in the BM group (p = 0.03). A statistically significant difference (p = 0.002) in c-myb expression was also observed between Barrett’s patients (20/42, 48%) and the control groups (9/63, 14%). In the BD patients, 21% (3/14) had increased c-myc mRNA expression compared with none in those with BM (p < 0.05) and BAC. No significant differences in mRNA expression levels were observed between ethnic groups for the genes analysed. In an attempt to determine whether the low expression level of c-myc in the study cohort may be related to possible gene-gene interaction, DNA samples of 199 individuals were subjected to genotyping of the functional GT-repeat polymorphism in the promoter region of the NRAMP1/SLC11A1 gene. Both these genes are involved in iron metabolism and c-myc is known to repress NRAMP1/SLC11A1. Genotype and allele frequencies were similar in all the groups studied with the 3/3 genotype being the most common. However, none of the three above-mentioned BD patients with increased c-myc mRNA expression had the 3/3 genotype. Therefore, although small in number, c-myc-NRAMP1/SLC11A1 interaction may be of adverse significance in patients with allele 2. TP53 mutation analysis was performed on 68 Barrett’s patients, and TP53 immuno-staining on oesophageal biopsy specimens of 55 subjects. Sporadic TP53 mutations were not identified in any of the patients with BM or dysplasia without BAC. Immuno-histochemistry staining of 2+ and 3+ intensity was similar in patients with metaplasia and dysplasia (58%). The low mutation frequency and relative non-specificity of TP53 immunostaining observed in Barrett’s patients seem to preclude its widespread use as a screening tool. TP53 mutation detection may however be useful for risk stratification once dysplasia has been diagnosed, as mutations G245R and D281Y were identified in two patients with BAC. Of the genes studied in the South African population, c-myb represents the most useful marker for early detection of an increased cancer risk in Barrett’s patients. In future, patients with Barrett’s oesophagus may benefit from genetic assessment to complement existing cancer surveillance and treatment strategies.

Thesis (MMedSc )--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The present study investigated in particularly the specific nature of the supporting stromal layer located between the implanted human cyst and host murine tissue, which has yet to be reported. During an initial phase of this study, the particular light microscopic properties of the existing hematoxylin and eosin (H&E) stained experimental cyst was investigated, with regards to the presence or absence of specific morphological features, namely spongiosis, exocytosis, epithelial keratinization, epithelial thickness and hyperplasia, and the vascularity and fibrosis present in the stroma of these experimental sections. Subsequent analysis reported significant spongiosis, in addition to increased exocytosis of immune cells and epithelial keratinization in a number of cysts. Additionally, increased epithelial thickness and hyperplasia was reported in only 2 / 10 experimental tissues, whereas increased vascularity was observed in the stroma following analysis of H&E and Special staining, such as Verhoeff-von Gieson and Masson trichrome results. During the second phase of the study, immunohistochemical analysis with a particularly wide array of antibodies raised against specific human and mouse antigens had been applied. This involved automated immunohistochemical staining with mouse anti-human primary antibodies, in addition to manual staining with rabbit anti-mouse primary antibodies. Subsequent visualization was achieved by means of linking to biotinylated secondary antibodies, and Streptavidin-HRP incubation for standard visualization, followed by counterstaining with Hematoxylin. Maintained positive expression of cytokeratins 5, 13, and 14 was demonstrated in both control human vaginal mucosa and experimental cysts, whereas similar findings were not reported for cytokeratin 1, given the vast keratinization which was observed. Human collagen type IV and laminin of the basement membrane reported positive expression in 9 / 10 and 6 / 10 control human vaginal mucosa tissues respectively. In comparison, negative mouse collagen type IV and laminin was reported in most experimental cysts compared to positive staining in positive control mouse tissues. Immunohistochemical staining for human elastin, fibronectin, von Willebrand factor, and fibroblasts revealed maintained positive staining in all control human vaginal mucosa and experimental cysts. However, maintained expression of CD34 (endothelial marker), CD1a (langerhans cells), and human VEGFR-3 in experimental cysts was not demonstrated, compared to positive expression in control human vaginal mucosa. Subsequent analysis of murine antigens illustrated uniformly negative staining for mouse fibronectin, langerhans cells (CD207), and fibroblasts, in addition to negative staining in positive control mouse tissue sections. Furthermore, negative staining for mouse VEGFR-2 was reported in all experimental cysts; however strong positive staining of this marker in mouse kidney tissue had been reported. The findings of this study suggested that the exact nature of the stromal layer is of both human and murine origin. Furthermore, the tissue region located beneath the human vaginal epithelium is suggested to be of human nature, whereas the second distinct region located at the periphery of experimental cyst tissues, is suggested to be murine origin; however the findings of immunohistochemical analysis could not illustrate definitively the exact nature of the intermediate stromal layer, but could in fact demonstrate a mixture of human and murine tissue. / AFRIKAANSE OPSOMMING: Die huidige studie het die spesifieke molekulêre en histologiese eienskappe van die stromale laag geleë tussen menslike sist- en muis velweefsel bestudeer, wat tans nog nie bekend is nie. Gedurende die eerste fase van hierdie studie is die besondere lig-mikroskopiese eienskappe van die bestaande hematoksilien en eosien (H&E) eksperimentele siste bestudeer, met betrekking tot die aan- of afwesigheid van spesifieke morfologiese eienskappe, naamlik spongiose, eksositose van immuunselle, epiteel keratinisasie, epiteel dikte en hiperplasie, en laastens die stromale vaskulariteit en fibrose. Gevolglike analise het daarop gedui dat beduidende spongiose, eksositose en epiteel keratinisasie gevind word in die eksperimentele siste in vergelyking met kontrole vaginal weefsel. Hierteenoor is die verdikking van die epiteel en hiperplasie in slegs 2 / 10 eksperimentele siste gevind, terwyl vermeerderde vaskulariteit aangedui is na gevolglike H&E en spesiale (soos byvoorbeeld Verhoeff-von Gieson en Masson trichrome) kleuringsresultate. Die tweede fase van die studie het die immunokleuring met verskeie mens- en muis spesifieke antiliggame behels, waarby die uitdrukking van verskeie mens antigene vergelyk is met dié van muis. As sulks is ge-automatiseerde immunohistochemie toegepas met muis primêre antiliggame, tesame met fisiese kleuring met konyn primêre antiliggame toegepas. Gevolglike visualisasie is aangedui deur middel van binding met sekondêre antiliggaam en Streptavidin- HRP, gevolg deur teenkleuring met Hematoksilien. Algehele behoud van positiewe uitdrukking van sitokeratien 5, 13, en 14 is bevind, terwyl sitokeratien 1 uitdrukking nie daarwerklik vergelykbaar is met dié van kontrole mens vaginale weefsel nie. Die uitdrukking van mens kollageen IV en laminien van die basaal membraan is verder bestudeer, en het egter positiewe kleuring in 9 / 10 en 6 / 10 van kontrole mens vaginale mukosa aangedui. In vergelykking hiermee kon die huidige bevindings egter net positiewe kleuring in 4 / 10 en 3 / 10 eksperimentele siste vir kollageen IV en laminien onderskeidelik, illustreer. Immunohistochemiese analise van menslike elastien, fibronektien, von Willebrand (vW) faktor en fibroblaste het op deurgaans positiewe uitdrukking van hierdie merkers aangedui in beide eksperimentele en kontrole menslike weefsel. In teenstelling hiermee is volgehoue uitdrukking van CD34 (endoteel merker), CD1a (Langerhans sel merker) en mens VEGFR-3 in ekperimentele siste egter nie illustreerbaar nie, in vergelykking met deurgaans positiewe uitdrukking van hierdie antigene in kontrole mens vaginale mukosa. In opvolging is deurgaans negatiewe uitdrukking van muis fibronektien, langerhans sel (CD207) en fibroblaste bevestig, terwyl negatiewe kleuring ook deurgaans in positiwe kontrole muis weefsel, bekom deur die disseksie van ‘n naakte muis, gevind is. Verder is ook negatiewe kleuring vir VEGFR-2 in alle eksperimentele siste gevind, terwyl egter sterk positiewe kleuring in muis nierweefsel as positiewe weefsel gevind is. Die resultate van die huidige studie het daarop gedui dat die stromale laag onderliggend tot mens vaginale epiteel van menslike oorsprong is, terwyl die periferale stroma onderliggend tot muis velweefsel, ongetwyfeld van muis oorsprong is. Laastens kon die spesifieke oorsprong van die tussenliggende stroma nie aangedui word nie, maar dat dit moontlik uit beide menslike- en muisweefsel bestaan.

The aims and objects of this work, as outlined in the introduction, were to a s s e s s the necropsy incidence of deaths due to heart failure in the African in Durban, to a s s e s s the necropsy incidence of the various aetiological types of heart failure with particular reference to right ventricular hypertrophy and failure, and to compare and contrast the incidence, complications, morbidity and mortality of heart disease in the Natal African with the same in other African and racial groups, both in South African and elsewhere. Many of the points emerging from this work merely confirm what has long been known, but others refute previous concepts. The all-age average necropsy incidence of deaths from heart failure in the African in Durban is of the order of 8%. This percentage does not, unfortunately, lend itself to straight comparison with most other series because of the high infant mortality shown in the present study. However, in considering deaths due to heart failure in the 10-plus age groups, the African still shows a lower mortality from heart disease in comparison with figures obtained for Indians or those reported for the Coloured and White races in South Africa. There are six major causes of heart disease in the African, which in order of frequency are, rheumatic heart disease, hypertensive heart disease, cardiomyopathy, cor pulmonale, pericarditis, and syphilitic heart disease. While little difference is apparent in the incidence of rheumatic and hypertensive heart disease, and possibly cor pulmonale, among the various races, cardiomyopathy, pericarditis and syphilitic heart disease are far more important causes of heart failure in the African by contrast with the other racial groups in South Africa. Although coronary a r t e r y disease is by comparison very uncommon in the African, cardiomyopathy, pericarditis, and syphilitic heart disease together claim as many deaths from heart failure in these people as does coronary heart disease among the Indian and White races in the Republic. Except for minor variations in the incidence of certain aetiological types, and the geographical distribution of endomyocardial fibrosis and cardiomyopathy/. . cardiomyopathy, the g e n e r a l p a t t e r n of h e a r t d i s e a s e among the Africans in Natal a p p e a r s to be s i m i l a r to that r e p o r t e d from other P r o v i n c e s in South Africa and most other c o u n t r i e s on the continent. Rheumatic h e a r t d i s e a s e is r e s p o n s i b l e for 21. 5% of all deaths from congestive h e a r t failure in the African in Durban. The immediate and the l a t e c a r d i a c complications of r h e u m a t i c fever in the Durban African a r e , on the whole, found to be no different from those r e p o r t e d in W e s t e r n communities. The findings in t h i s study t h e r e f o r e refute the view that r h e u m a t i c h e a r t d i s e a se i s infrequent in the African after the age of 40 y e a r s , and failed to support the suggestion that the d i s e a s e affects them m o r e s e v e r e l y or that death from r h e u m a t i c heart d i s e a s e o c c u r s at an e a r l i e r age in t h i s r a c e . While it is a g r e e d that s e v e r e valvular deformity in young African subjects (under 15 y e a rs of age) o c c u r s c o m p a r a t i v e l y m o r e frequently, it must be stated that this is in no way p e c u l i a r to the African, similar lesions being o b s e r v e d in Indian s u b j e c t s of c o r r e s p o n d i n g age. Hypertensive h e a r t d i s e a s e is common among the African in Durban, accounting among t h em for 18. 9% of all deaths from congestive h e a r t f a i l u r e. While both e s s e n t i a l and secondary forms of h y p e r t e n s i o n occur in the local indigenous population, the former appears to be m o r e common, with a peak incidence in the seventh decade of life. Secondary hypertension, mostly r e n a l in origin, is an i m p o r t a n t cause of h y p e r t e n s i v e congestive c a r d i ac f a i l u r e in the fourth decade. The wide v a r i a t i o n s in the type of h y p e r t e n s i on r e p o r t e d from the different regions in Africa, and the doubt e x i s t i n g as r e g a r ds the significance of focal lesions in the kidneys, point towards the need for g e n e r a l l y accepted c r i t e r i a in the diagnosis of r e n a l hypertension, p a r t i c u l a r ly with r e g a r d to chronic phylonephritis. Cardiomyopathy c l a i m s 15. 8% of all deaths from congestive heart f a i l u r e in the local African population. While many of the pathological changes o c c u r r i n g in the h e a r t in t h i s d i s e a s e were found to be s i m i l a r to those of other i n v e s t i g a t o r s , c e r t a i n f e a t u r e s , relating to c a r d i a c hypertrophy and s t r u c t u r a l a l t e r a t i o n s in the pulmonary v e s s e l s , have been e s p e c i a l ly i n v e s t i g a t e d / . . . investigated and results obtained in this series of cases show that whereas pure right ventricular hypertrophy is uncommon in cardiomyopathy biventricular hypertrophy with predominance of the right ventricle is the most frequent form of cardiac enlargement in such cases. Equal hypertrophy of the ventricles is the next common form of enlargement; left ventricular predominance is by far the least frequent, and no case of exclusive left ventricular hypertrophy was encountered. Although structural alterations in the pulmonary a r t e r i e s , indicating pulmonary a r t e r i a l hypertension, were observed in a large number of cases investigated, such changes were in no way specific to cardiomyopathy, since similar changes were observed in cor pulmonale due to emphysema and also in some cases of hypertensive congestive heart failure. Structural alterations in the small muscular pulmonary a r t e r i e s and arterioles were also identical with those found in emphysema. Whereas fresh pulmonary emboli and infarcts were frequently encountered and were often of such degree as to be the immediate cause of death, chronic pulmonary thrombo-embolism of an extent sufficient to have been the cause of right ventricular predominance was seldom found. It is suggested that the cause of the pulmonary hypertension and certain pathological changes in the heart in cardiomyopathy may lie in some form of exogenous toxin, possibly related to the practice of herbal medication among the African people, which acts as an a r t e r i a l vasoconstrictor in both the pulmonary and systemic circulations. This would suggest that the a r t e r i a l changes observed in the lungs are probably the result and not the cause of pulmonary hypertension. The incidence of cor pulmonale as a cause of congestive heart failure among the African in Durban is of the order of 12%. It has been shown that almost one quarter of all cases of right ventricular failure remains undiagnosed, as regards aetiology, at routine necropsy. The latter finding pointed towards the need for an investigation of the causes of right ventricular failure in the African. Such a study was undertaken and special methods of investigation w e r e / . . . were used as aids towards a more conclusive diagnosis. This study showed fibrosing lung disease, due particularly to the late complications of pulmonary tuberculosis, to be the most important cause in the production of chronic cor pulmonale in the African in Durban. The development of cor pulmonale in such cases depends not only on the presence of pulmonary parenchymal damage by fibrosis, but also on the associated pleural thickening, adhesions between chest cage and diaphragm, emphysema, and the curtailment of the pulmonary a r t e r i a l bed. In this series, all cases of fibrosing lung disease with cor pulmonale investigated for cardiac hypertrophy by means of separate weighing of the ventricles, showed evidence of pure right ventricular enlargement, indicating no significant chronic burden on the left ventricle of a diastolic overload through bronchial shunting. Thrombo-embolic cor pulmonale, hitherto believed to be r a r e in the African, emerges as the most important cause of acute cor pulmonale and the second most common cause of the more chronic varieties of the disease. The usual pathological type of pulmonary thrombo-embolic disease observed in this study is one in which fairly large pulmonary a r t e r i e s , as opposed to those of microscopic size, were involved and in consequence infarction was frequent. The lack of completely organised lesions, and the relatively small increase in total heart weights (majority below 400 Gms) suggest a rapid course in these cases, measured in months rather than in years. The usual source for pulmonary emboli was found to be the veins draining the lower limbs, particularly the deep calf veins. Whereas a predisposing factor for the development of venous thrombosis was found in just over half the number of cases investigated, in 44% of all cases of thrombo-embolic cor pulmonale in this study no cause was found at necropsy for the peripheral venous thrombosis. Of the predisposing causes encountered a posteriorly placed amoebic liver abscess emerges as an interesting aetiologic factor in the development of thrombo-embolic cor pulmonale because of its ability to produce hepatic vein and inferior vena caval thrombosis. Emphysema, usually in association with chronic bronchitis, was found to be the third most common cause of chronic cor pulmonale among Africans/ . . . Africans in Durban, and was encountered mainly in its mixed form (centrilobular and panlobular). Although structural alterations in the pulmonary a r t e r i es were noted in a significant number these were sometimes of insufficient degree to be the cause of pulmonary hypertension, thereby suggesting some other factor in the production of a raised pulmonary a r t e r i a l p r e s s u r e . Results of separate ventricular weighing in these cases show exclusive right ventricular hypertrophy, again indicating strain solely on the right ventricle. Bilharzial cor pulmonale, although one of the r a r e r causes of cor pulmonale in the African in this series, is suspected to be probably more frequent than hitherto believed. The lack of obvious macroscopic changes in the lungs of such cases is stressed, and while this may account for omissions in diagnosis, a sudden recent increase in the incidence of bilharzial cor pulmonale might also suggest that the disease is becoming more severe. Primary pulmonary hypertension as a cause of cor pulmonale in the African is r a r e , being suspected in only one case in this series. In keeping with the generally high incidence of infective diseases in the African, pericarditis as a complication of tuberculosis and hepatic amoebiasis, and the cardiac complications of syphilitic aortitis still occupy major positions among the causes of congestive heart failure in this population; together accounting for 12.4% of all deaths from congestive heart failure. Tuberculosis and amoebiasis are important not only in the production of p e r i c a r d i t i s , but, as mentioned, also play an important part in the development of cor pulmonale. Syphilitic heart disease, besides being a significant factor in the production of congestive heart failure, is the most important cause of a sudden cardiac death in the African. In conclusion it may be said that while little can be achieved with regard to the control of diseases for which no cause has as yet been found, the elimination of infective conditions such as tuberculosis, amoebiasis and syphilis will result in a significant drop in the incidence of death and disability from heart failure in the African in Natal. / Thesis (M.D.)-University of Natal, Durban, 1967.

Infiltrative morphological mimicry at sites of biopsy-proven nodular basal cell carcinoma has been described. The immunoprofile of scar BCCs (scar BCCs,SBCCs) has not been documented. The aim of this study was to assess the histopathological spectrum, stromal (fibronectin, laminin, actin, desmin and vimentin) response and proliferation (bcl-2, MIB1 and p53) status of SBCCs. Twenty nine BCCs occurring in scars, unrelated to previous malignancy (de novo scar BCCS, DN-SBCCs), 27 BCCs that were incompletely excised and regrew at the same site (regrowth scar BCCs, RG-SBCCs) and 25 BCCs that were completely excised with tumour free margins, but recurred at the same site (recurrent scar BCCs, R-SBCCs) were accessed from the files of the Department of Pathology and Plastic and Reconstructive Surgery of the Faculty of Medicine, University of KwaZulu Natal, and formed the basis of this study. The morphological features of DN-SBCCs was pure (3%), predominantly nodular (79%), micronodular (7%) and infiltrative (11 %). RG-SBCCs were predominantly nodular (82%), micronodular (7%) and infiltrative (11%). RSBCCs were predominantly nodular (80%), micronodular (4%) and infiltrative (16%). The majority of DN-SBCCs, RG-SBCCs and R-SBCCs showed intact basement membrane laminin staining, while two (7%) DN-SBCCs showed 1 + and 2+ loss of basement membrane laminin staining. Three (11 %) and two (8%) RG-SBCCs and R-SBCCs,respectively, showed 2+ or 3+ basement membrane laminin discontinuity. The majority of DN-SBCCs (83%), RGSBCCs (75%) and R-SBCCs (88%) were actin negative. No desmin immunopositivity was demonstrated in the epithelial or stromal components of DN-SBCCs, RG-SBCCs and R-SBCCs. All BCC groups showed high 3+ or 4+ vimentin immunopositivity. The majority (>50%) of the SBCCs showed low (2+) bcl-2 immunopositivity. There was no significant difference in p53 immunopositivity in all SBCCs. SBCCs demonstrate phenotypic and immunophenotypic heterogeneity. That DN-SBCCs with the infiltrative and micronodular patterns have not recurred implies that the histomorphology is a pseudo-aggressive pattern. A similar view could pertain to RG-SBCCs, but because the scar did not cicatrise the incompletely excised BCC implies that the histomorphology of RG-BCC may be a potentially more aggressive phenotype. The recurrence of a completely excised basal cell carcinoma may be viewed as a feature of an aggressive tumour, especially when the recurrent BCC contains micronodular and infiltrative components. However, as most R-SBCCs occurred at head and neck sites that are exposed to ultraviolet light, it is also possible that these are simply new BCCs occurring within scars in head and neck sites prone to BCCs. Furthermore, these R-SBCCs were not destructive tumours. CONCLUSION: None of the infiltrative foci of DN-SBCCs demonstrated laminin loss. Three of 5 with intra-epithelial actin immunopositivity also demonstrated low bcl-2 and high p53 staining, immunoprofiling these with an aggressive infiltrative component. Of 11 RG-SBCCs with high p53 staining, 4 had high p53 staining in the infiltrative component, but only one had a low bcl-2 composite score and low bcl-2 score in the infiltrative focus. In addition, these infiltrative foci demonstrated intraepithelial MSA positivity and a "VA" immunophenotype of the stromal cells, indicating one RG-SBCC with an established, aggressive immunophenotype. Those positive with one or more, but not all, aggressive immunostains, are hypothesised to be RG-SBCCs evolving/developing an aggressive immunophenotype. Only one R-SBCC, with a predominantly infiltrative pattern, had a "full-house" of aggressive immunostaining in the infiltrative foci: low bcl-2, high p53, 2+ laminin discontinuity and intra-epithelial and stromal MSA positivity. Of significance is that 7 with a predominant nodular pattern had a high p53 score. Of these, 5 had high bcl-2 scores. Hence, while high p53 may be a feature of aggressive growth, it is important that this staining be complemented with that of bcl-2, laminin and MSA. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Durban, 2006.

This study examines the effect of progesterone-only injectable contraceptives, and medroxyprogesterone acetate (Depo-Provera) in particular, on the cells of the uterine cervix. Cervical and vaginal smears were taken before commencement of therapy and at 3 and 6 month intervals thereafter on 79 asymptomatic women attending a family planning clinic. Results of hormonal and cellular measurements before and after therapy were compared. menstrual cycling was also studied. The effect on Methods used were hormonal maturation indices, image analysis measurements and microscopic observation of cellular . features. The latter included anisocytosis, anisokaryosis, karyomegaly , plaque formation, cytoplasmic wrinkling, nuclear grooving, hypertrophy, atrophy, cytoplasmic moulding and density, retarded maturation and nuclear protrusions. Squamous, endocervical and metaplastic cells were examined. Analysis of the results showed that progesterone-only contraceptives produce all of the above to a greater or lesser degree resulting in an increased relative nuclear area which may be confused with intraepithelial neoplasia. This is due to the production of a folate deficiency at target organ level which interferes with cell division and slows the maturation process. This effect enabled further observations to be made leading to the establishment of the origin and content of the nipple-like protrusions which occur in endocervical cells in response to hormonal activity. Physiological effects included amenorrhoea and irregular menstrual cycling. Most women showed evidence of interference with normal cycling to a varying degree. The documented cellular changes were shown to modify the expression of common inflammatory and neoplastic conditions of the uterine cervix. These included trichomoniasis, herpesvirus cervicitis, human papillomavirus infection, folate deficiency, cervical intraepithelial neoplasia and invasive carcinoma as well as multiple pathologies. The potential for diagnostic error was examined. New diagnostic criteria were formulated based on the comparison of cellular features found in the presence of the contraceptive with those found under normal conditions. It is anticipated that these criteria will facilitate the cytological diagnosis of pathological conditions of the uterine cervix in users of depo-medroxyprogesterone acetate (DMPA), leading to increased accuracy and improved and better directed patient management. / Thesis (M.Med.Sc.)-University of Natal, Durban, 1993.

The major physiological function of the carotid body is to respond to a low partial pressure of oxygen in the systemic arterial blood. The structure and functions of the adult carotid body have been extensively investigated over the past fifteen years. However, the carotid body in children has been relatively neglected with only a handful of studies being performed. To date, no study has been undertaken to investigate the effects of intrauterine hypoxia on the carotid body of foetuses. Clinically, intrauterine growth retardation has been ascribed, amongst other causes, to placental insufficiency that results in chronic hypoxia in the fetus. Intrauterine growth retardation can be divided into two types: - Type I (symmetrical) and type II (asymmetrical). In Type II intrauterine growth retardation, growth retardation does not become clinically evident until the third trimester. There is relative brain sparing with a greater deprivation in the size of abdominal organs, such as the liver and the kidneys. Previous studies have shown that there is no correlation between volume of the carotid body and hypoxia in children. However, Heath et al. made the observation that there are three variants of chief cells (progenitor, light and dark) within the carotid body and that an increase in the relative percentage of the dark subtype is an indicator of hypoxia. Using this observation, the present study set out to test two hypotheses: Firstly, whether the carotid body is functional in utero; and secondly whether there are any objective morphological changes in the carotid bodies of fetuses that have been subjected to intrauterine growth retardation. The carotid bodies from 72 fetuses with a gestational age between thirty and forty weeks were removed from the archived autopsy material, and differential cell counts were performed of the various cells present within the carotid bodies, using haematoxylin and eosin stained sections of the carotid bodies. The cases were assigned to three groups: - I) cases that had clinical and pathological evidence of intrauterine growth retardation, 2) negative controls and 3) positive controls. The three main groups were categorised as follows: -: (1) Intrauterine growth retardation (all cases with a weight for gestational age that is below the tenth centile and a brain to liver ratio of greater than four.) (2) Negative controls (all cases in whom there is a normal weight for age, a brain to liver ratio of less than three and no histological evidence of an episode of significant hypoxia before death). (3) Positive controls (all cases in whom there was clinically significant hypoxia present before death). The groups comprised of: 20 hypoxic positive controls, 15 negative controls, and 16 test cases which had suffered from intrauterine growth retardation. The remaining 21 cases were 7 dysmorphic infants, 3 congenital infection cases (congenital syphilis) and 11 cases that fitted the negative control criteria but had suffered significant hypoxia, thus excluding them from that category. The results showed that no significant difference was present in the percentage of sustentacular cells between any of the three groups. The results of the percentage of dark chief cells were as follows: l) mean percentage of dark chief cells in the intrauterine growth retardation group was 21.1 ±10.9%. 2) mean percentage of dark chief cells in the negative controls was 12.3 ±7.3%. 3) mean percentage of dark chief cells in the positive controls was 21.2 ±9.8%. A significant difference was present between the intrauterine growth retardation cases and the negative controls p=0.013, and between the positive and negative controls p=0.006. The dark chief cell count in the intrauterine growth retardation group showed no significant difference from the positive controls. No age-related difference appeared to be present in any of the groups. The conclusions reached are: a) Clinical hypoxia correlates with morphological changes in the carotid body, manifesting as an increase in the percentage of dark chief cells. b) intrauterine growth retardation cases show similar morphological changes in the carotid body to cases that have suffered from clinical hypoxia. c) therefore, by deduction intrauterine growth retardation fetuses have probably also been exposed to significant hypoxia while in utero. d) the fact that morphological changes in response to hypoxia are occurring in the carotid bodies of fetuses is an indication that the carotid body may be functional in utero. The results of the study indicate that a dark chief cell percentage of greater than 20% indicates that the fetus has been subjected to significant hypoxia, while a percentage of less than 10% indicates that it has not. A percentage of between 10 and 20% is unhelpful in determining whether hypoxia has taken place. The results of this study indicate that histological examination of the carotid bodies in neonates suspected of intrauterine growth retardation could be a useful additional means of assessment.

This study was undertaken as a result of the occurrence of a large number of deaths among the local Black population from the use of herbal medicines prepared from the rootstock of Callilepis laureola known to the Zulus as impila. The salient clinico-pathological features in these cases were hypoglycaemia, centrilobular zonal liver necrosis and acute renal tubular necrosis. The purpose of this study was to investigate fully the clinical, biochemical and pathological aspects of the toxicity produced by Callilepis laureola (impila). The first part of the investigation consisted of an assessment of all cases of death due to acute liver necrosis diagnosed by necropsy at King Edward VIII Hospital, Durban. A review of clinical and necropsy records of 21687 consecutive post-mortems performed on Black patients during a 20 year period showed that acute liver necrosis was the major contributing cause of death in 447 patients. In 263 cases the hepatic lesion was centri lobular zonal necrosis with associated acute tubular necrosis (Group A); while in 184 cases the I iver necrosis was of the massive or submassive type (Group B). A comparative assessment of these two groups as regards necropsy prevalence, age and sex distribution and the clinical, biochemical and pathological findings was undertaken. This study shows that the combination of hypoglycaemia, centri lobular zonal liver necrosis and acute renal tubular necrosis due to Callilepis laureola (impila) poisoning is a distinct clinico-pathological entity and differentiates this group from cases of acute massive and submassive liver necrosis resulting in most cases from fulminant viral hepatitis. In the search for the toxic components of the root of Callilepsis laureola several compounds were isolated. These were atractyloside, carboxyatractyloside, two thymol related oils and a carbohydrate. The thymol related oils as well as the carbohydrate were found to be non-toxic in laboratory rats. The crude methanol extract of the root of Callilepsis laureola, when injected intraperitoneally into laboratory rats, produced centrilobular zonal liver necrosis and acute renal tubular necrosis, the lesions identical to those seen in patients who had died after intake of impila prescribed by witchdoctors and other dispensers of herbal medicines. On the other hand intraperitoneal injections of the purified compound atractyloside caused acute renal tubular necrosis and hypoglycaemia in laboratory rats but failed to produce liver necrosis. Carboxyatractyloside also failed to cause liver necrosis. This indicated that there may be at least two toxins contained in the rootstock of Callilepsis laureola, one causing the liver lesion and the other (atractyloside) causing nephrotoxicity and hypoglycaemia. Repeated attempts at isolating the hepatotoxin have failed; the liver toxin or toxins being lost during the process of extraction and purification. Identification of the hepatotoxin awaits further investigation. It is possible that the liver necrosis may be caused by a metabolite or that it may be a synergistic effect of two or more compounds. / Thesis (MD)-University of Natal, 1983.