Hypertensive left ventricular hypertrophy (LVH) increases the risk for the development of heart failure with systolic chamber dysfunction. However, the exact mechanisms and hence best therapeutic approach to prevent this transition process is uncertain. One potential mechanism is through excessive β-adrenergic receptor (-AR) activation, but the risks of β-AR blocker therapy may outweigh the benefits. Since activation of -AR augments function of the renin-angiotensin-aldosterone system, I therefore explored whether mineralocorticoid receptor (MR) blockade prevents the transition from hypertensive LVH to systolic chamber decompensation produced by excessive β-AR activation, and the mechanisms thereof. The role of hypertensive LVH as a predisposing factor to systolic chamber decompensation post-myocardial infarction (MI) is controversial. In the present thesis I therefore also evaluated this question. The effect of spironolactone (SPIRO, 80 mg.kg-1.day-1), an MR blocker, on LV chamber remodelling and function was evaluated in spontaneously hypertensive rats (SHR) in whom decompensation was induced by administering a low dose of the -AR agonist, isoproterenol (ISO) for 4.5 months. ISO administration resulted in an increased urinary aldosterone excretion and LV cavity dimensions, a right shift in LV diastolic pressure-volume relations, and a decreased LV relative wall thickness without further enhancing an increased myocardial norepinephrine (NE) release in SHR. ISO reduced LV systolic chamber function (decreased LV endocardial fractional shortening and the slope of the LV systolic pressure- volume relationship) without modifying intrinsic myocardial systolic function (as assessed from LV midwall fractional shortening and the slope of systolic stress-strain relationship). SPIRO abolished ISO-induced chamber dilatation, wall thinning and systolic dysfunction, but failed to modify blood pressure, volume preloads, intrinsic myocardial systolic function, or myocardial NE release. These results suggest that MR activation, through load-independent effects, may be critical in mediating the transition from compensated hypertensive LVH to dilatation and LV systolic chamber dysfunction. In SHR, ISO increased myocardial matrix metalloproteinase (MMP)-2 activity (zymography) after only 4-5 days of administration, a change that was associated with MMP-2, but not TIMP expression. The increased MMP-2 activity persisted until 4.5 months of the study and these changes were prevented by SPIRO. At 4.5 months, ISO resulted in increased non-cross-linked, but not cross-linked myocardial collagen concentrations in SHR, an effect that was abolished by SPIRO. Although at 4.5 months ISO administration was not associated with an increased cardiomyocyte apoptosis (TUNEL), an early (4-5 days) ISO-induced apoptotic effect was noted, which was prevented by SPIRO. Neither ISO nor SPIRO influenced cardiomyocyte length (image analysis and flow cytometry) in SHR. Thus MR blockade may prevent the adverse effects of β-AR activation in hypertensive LVH through alterations in the cardiac interstitium and cardiomyocyte apoptosis. Six-to-seven months after ligation of the left anterior descending coronary artery, LV myocardial systolic function as assessed from % shortening of the non-infarcted lateral wall segmental length determined over a range of filling pressures (ultrasonic transducers placed in the lateral wall in anaesthetized, open-chest, ventilated rats) and % thickening of the posterior wall (echocardiography) was reduced in infarcted SHR (SHR-MI) (p<0.05), but not in normotensive Wistar Kyoto (WKY-MI) animals as compared to corresponding controls (SHR-Sham, WKY-Sham). This change in regional myocardial function in SHR-MI, but not in WKY- MI, occurred despite a similar degree of LV dilatation in SHR-MI and WKY-MI rats and a lack of difference in LV relative wall thinning, LV wall stress, apoptosis (TUNEL) or necrosis (pathological score) between SHR-MI and WKY-MI rats. Although the change in regional myocardial function in the SHR-MI group was not associated with a greater reduction in resting global LV chamber systolic function (endocardial fractional shortening-FSend and end-systolic elastance [LV Ees] determined in the absence of an adrenergic stimulus), in the presence of an ISO challenge a reduction in LV Ees in SHR-MI compared to WKY-MI and SHR and WKY-Sham rats was noted (p<0.04). These data suggest that with chronic MI, the hypertensive heart is susceptible to development of viable tissue myocardial dysfunction, a change which cannot be attributed to excessive chamber dilatation, apoptosis or necrosis, but which in-turn, contributes toward a reduced cardiac adrenergic-inotropic reserve. The present thesis therefore suggests that MR blockade may prevent the transition from hypertensive LVH to systolic chamber decompensation, and that pre-existing hypertensive LVH increases the susceptibility to a depressed LV regional myocardial systolic function in the non-infarcted LV myocardium subsequent to MI, an effect that translates into a reduced inotropic reserve.

Hepatitis B virus (HBV) is a major global public health burden, with over 350 million people chronically infected. This results in approximately 600,000 liver cancer-related deaths annually. Chronic HBV infections are normally managed with long-term anti-HBV therapeutics, such as reverse transcription inhibitors, which target post-transcriptional viral processes without affecting the cccDNA. Treatment failure however is largely as a result of the stability of this episomal viral DNA. The cccDNA minichromosome serves as a reservoir of HBV DNA and is capable of re-establishing viral replication following withdrawal of treatment. Designer nucleases, like transcription activator-like effector nucleases (TALENs), have recently been used to create double stranded breaks (DSBs) at target-specific endogenous DNA loci. These nucleases are designed as pairs, which upon dimerisation cleave double-stranded DNA. Subsequent activation of the cellular non-homologous end-joining (NHEJ) pathway often results in targeted mutagenesis at the DSB site. As TALENs may be designed to bind to any DNA sequence, they are commonly used as genetic engineering agents. Inactivation of HBV cccDNA, using these engineered TALENs, presents a unique approach to disabling viral replication permanently. To investigate this, a panel of TALENs targeting the core (C), surface (S) and two different polymerase (P1 and P2) regions of HBV cccDNA were generated using a Golden gate modular assembly approach. TALENs were initially tested in two liver-derived cell lines. Firstly as transient co-transfections in Huh7 cells using a HBV replication competent plasmid, followed by long term investigations in HepG2.2.15 cells which model HBV replication in vitro. Inactivation of HBV was determined by measuring markers of viral replication, whilst TALEN-mediated targeted disruption was verified by T7 endonuclease 1 (T7E1) or CELI endonuclease assays and sequencing. In vitro, the S TALEN inhibited HBsAg secretion by 80% in Huh7 cells and 60% in HepG2.2.15 cells. Furthermore, S TALEN-mediated targeted disruption occurred in 35-47% of cccDNA copies, whilst the C TALEN resulted in 11% targeted disruption of cccDNA in without inhibition of HBsAg expression. The P2 TALEN showed no anti-HBV efficacy, however the P1 TALEN inhibited HBsAg expression by up to 60% without any evidence of site-directed cleavage. As this TALEN binding site spans the HBV Enhancer I sequence, knock-down of HBsAg expression is most likely to occur as a result of transient transcriptional repression. To confirm whether permanent repression of HBV transcription could be achieved, a KRAB-based transcription activator-like repressor (rTALE) targeting the HBV pre-S2 promoter was generated. Using an in vitro reporter gene assay, the pre-S2 rTALE inhibited luciferase expression by up to 90%. However this was only achieved using high molar concentrations of the repressor, suggesting multiple rTALEs may improve HBV transcriptional repression. As the S and C TALENs displayed significant anti-HBV efficiency in vitro, they were tested in a murine hydrodynamic injection model of HBV replication. In vivo, the S TALEN inhibited HBsAg secretion by 95% and induced disruption in 77–87% of HBV DNA targets. In addition the C TALEN inhibited HBcAg expression and induced disruption in 78-93% of HBV DNA targets. Additionally, serological analysis showed a reduction in circulating virions and no apparent liver toxicity, as determined by real-time PCR (qPCR) and aspartate transaminase (AST)/ alanine aminotransferase (ALT) liver function tests respectively. Deep sequencing at the S and C TALEN binding sites showed targeted mutagenesis of HBV DNA in samples extracted from murine hepatocytes transfected with TALENs, however wild-type sequences were exclusively detected in mice that had not been treated with anti-HBV TALENs. Furthermore, frameshift deletions were predominantly detected indicating major disruptions in the HBV surface and core sequences. These results indicate that TALENs designed to disable and silence HBV cccDNA are effective both in vitro and in vivo and as such provide a promising therapeutic approach to treat this serious infection.

Anopheles funestus is a major vector of malaria in the southern African region. Insecticide resistance to pyrethroid and carbamate insecticides has been recorded in populations of this species in South Africa and Mozambique. This study aimed to determine the relationship between pyrethroid resistance and gene expression of two closely related genes, CYP6P9 and CYP6P13, by age and sex in a resistant strain An. funestus from southern Africa, FUMOZ-R. The insecticide susceptibility assays showed that percentage survival in both FUMOZ-R sexes significantly decreased as age increased. The mRNA expressions of CYP6P9 and CYP6P13 were higher in FUMOZ-R relative to the insecticide susceptible strain (FANG). The expression of permethrin resistance varies with age in An. funestus FUMOZ-R. The results indicate that other genes may also be involved in insecticide resistance. In addition to this, the expression profile of other metabolic genes involved in insecticide resistance was also investigated. A microarray based approach was used to identify genes differentially expressed in FUMOZ-R and FANG. As the full set of detoxification genes in An. funestus are unknown, this study investigated the utility of the An. gambiae detox chip to screen for differentially expressed detoxification genes in An. funestus. After optimization of the hybridisation conditions, over 90% of the probes showed a positive signal. Only three genes were significantly (P<0.001) differentially expressed in the females, CYP6P9, COI and CYP6M7. The same genes were also significantly differentially expressed in the adult males, together with an additional 21 transcripts. The third part of this study investigated the gene expression in the first instar, fourth instar and 3-day old adults in FUMOZ-R using the An. gambiae detox chip. The variation in metabolic enzyme gene transcription at the different developmental stages in An. funestus are not known. The identification of differentially transcribed genes at the different life stages provides some insight into the role and function of these genes. A large number of cytochrome P450s (monooxygenases), esterases, glutathione S-transferases (GSTs) and other additional genes were differentially expressed in all life stages. This study provided vital information regarding genes potentially involved in pyrethroid resistant and is the first to provide metabolic or detoxifying transcription gene information in An. funestus.

Introduction The association between tuberculosis (TB) and malnutrition is well known. Malnutrition also weakens the immune system increasing the chance of latent TB progressing to active disease. Nutritional interventions can help improve overall quality of life and can reduce susceptibility to opportunistic infections including all forms of Oral Candidiasis (OC) which includes: (1) pseudomembranous candidiasis (oral thrush), (2) atrophic (erythematous) candidiasis, (3) hyperplastic candidiasis, and (4) angular cheilitis. This secondary data analysis of a longitudinal follow-up study evaluates the impact of a fortified supplementary food on OC among adult TB patients over a three month period. Results At baseline, an overall prevalence of 33% of OC (27 out of 83) was found in 83 adult TB patients; (pseudo-membranous 46% (16 out of 35), erythematous 26% (9 out 35), angular chelitis 20% (7 out 35) and hyperplastic 8% (3 out of 35). Thirty five different types of OC were found in 27 of the subjects some of whom manifested with more than one type of OC. Almost 89% of these TB patients had low levels of malnutrition (8% for selenium, 55% for iron, 62% for Vit-A, 42% for albumin, 47% for Vit-D and 34% for zinc). Their p values related to OC were (p=0.64 for selenium, p=0.74 for iron, p=0.19 for Vit-A, p=1 for albumin, p=1 for Vit-D and p=0.09 for zinc) showing no statistically significant difference for malnutrition in each different type of micronutrient related to OC at baseline. However, there was a statistically significant difference in HIV status (p=0.01) related to OC among factors such as sex (p=0.34), employment status (p=0.74), ARV status (p=0.46) and wellbeing (p=0.18) at baseline. OC was statistically significant at both 2nd and 3rd visits using univariate analysis p=0.04 (95%CI 0.22 to 0.97) and p=0.00 (95%CI 0.06 to 0.43) and also multivariate analysis p=0.01(95%CI 0.17 to 0.85) and p=0.00 (95%CI 0.04 to 0.34) with reference to the 1st visit (the prevalence of OC was significantly decreased in both 2nd and 3rd visits). For different types of clinical OC, pseudomembranous candidiasis was the only type of OC that showed statistically significant difference at the 3rd visit in both univariate analysis (p= 0.01, 95%CI 0.01 to 0.46) and multivariate analysis (p= 0.00, 95%CI 0.01 to 0.38) with reference to 1st visit. Discussion and Conclusions This study found no significant association between overall micronutrient level and the presence of OC at baseline. However, micronutrient interventions to the 83 adult TB patients receiving treatment at Johannesburg city clinics located in Alexandra showed a decrease in prevalence of different types of OC in both 2nd and 3rd visits. This analysis showed encouraging results which indicated a beneficial effect of e’Pap in adult TB patients.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Public Health Johannesburg, May 2015 / Worldwide, an estimated 800 women die each day from preventable causes related to pregnancy and childbirth, the majority in low-and middle-income countries (WHO, 2014:1). The Safe Motherhood Initiative (SMI) aims to achieve safe pregnancies and childbirth, but maternal mortality remains a significant problem in Botswana. Aim and Objectives: The aim of this study was to analyse the implementation process of the SMI policy in Botswana, with specific reference to the training component. The specific objectives of the study were to: describe the context of policy implementation; analyse the content of the SMI policy guidelines; describe the process of implementation of the 2005 SMI policy guidelines; describe the key policy actors, their roles and their influence on the implementation of the policy; and describe the factors influencing the implementation of the SMI policy in Botswana. Methods: The study used a contemporary health policy analysis framework. During 2008, key informants were selected purposively in the southern health region of Botswana. Following informed consent, 12 in-depth interviews were conducted with key informants to obtain their views and perceptions of the content, context, process and the actors of the SMI policy implementation process. The data were analysed using thematic content analysis. Results: The study found that there was high level government commitment, with the SMI driven by the Ministry of Health. Key successes of the SMI policy included: the integration of the Prevention of Mother-to-Child Transmission (PMTCT) of HIV component into the SMI policy, the integration of SMI into the midwifery curriculum and the development, standardisation and distribution of reference manuals or protocols. However, legislative and health system barriers, as well as unsustainable funding, insufficient consultation with and support by stakeholders, and inadequate coordination of the policy process hindered the successful implementation of the SMI policy. Conclusion: The findings draw attention to the value of stakeholder involvement in policy formulation and implementation; the importance of addressing policy implementation barriers and resource availability; and the need for effective coordination and communication.

A Dissertation submitted to the Department of Physiology, University of Witwatersrand, Johannesburg in fulfilment of the requirements for the degree of Master of science in Medicine. / The management and prevention of ankle sprains had been a topic of controversy in the sport medical literature to date, with various rehabilitative and preventative protocols having been suggested. In part one of this study, a relatively new rehabilitative device, the Cybex II Dynamometer,was used to determine whether the rehabilitation period of ankle sprain injuries could be reduced in recently injured patients. In part two, the Cybex II Dynamometer was used in conjunction with other training techniques in a preventative trial of first league volleyball players, to see whether the incidence of ankle sprains (which is particularly high in this population group) could be reduced. Although the experimental group was discharged almost 35 percent sooner than the control group in part one, the difference was not found to be statistically significant. In part two the preventative measures resulted in a notable difference in the incidence of injuries (32 percent in the control group compared to 11 percent in the experimental, group). Differences were just not statistically significant (p=O.059). / Andrew Chakane 2018

Objective: To investigate the association between functional foods and dental caries experience in Quebec children. Methodology: A cross-sectional analysis of the baseline wave of the QUALITY cohort was conducted and included a total of 195 children aged 8-10 years. Dietary information was collected by the use of 24--hour recalls. The adequate and inadequate intakes of specific nutrients were assessed in order to create a functional foods index. Dental caries experience was measured by DMF-S index and further categorized into presence and absence of caries. Data were collected on socio-demographic, oral health behaviour and anthropometric measures (height and weight). Data analysis involved logistic regression. Results: Girls eating functional foods were 89% less likely to have 1 decayed or filled tooth. [OR= 0.11 95% CI= (0.01-0.92)]. Conclusion: Functional foods had a protective effect against dental caries, specifically among girls in this sample of children.

Errata sheet has been pasted onto the front end-paper. / Bibliography: leaves 208-217. / x, 217 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Outlines a systematic synthesis and testing of continual sterilization design. Principal aim is to evaluate and develop mathematical models for sterilization, undertake experimental studies for determining thermal inactivation effects on continuous processing of a liquid containing contaminant bacteria and compare the data obtained with those predicted by a selected model. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 2001?

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 5 uppsatser.

Diss. Stockholm : Karol. inst.