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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
741

An evaluation of the effectiveness of a clinic-based HIV/AIDS counselling course on trainee functioning at work sites

Arendse, Carmen January 2002 (has links)
Magister Psychologiae - MPsych / The Western Cape AIDS Training,Information and Counselling Centre (ATICC) primarily focuses on the development and provision of information and different types of training programmes on HIV/AID/STIs. The Director of the Health Service of the Cape Metropolitan Council was invited by ATICC to select seven health educators and nurses who were involved in health education and counselling in their local clinics to complete a six-month training course. The objective of this study was to evaluate the effectiveness of the ATICC training course on the counselling practice of trainees at their clinics. / South Africa
742

African traditional medicine-antiretroviral interactions : effects of Sutherlandia frutescens on the pharmacokinetics of Atazanavir

Müller, Adrienne Carmel 28 March 2011 (has links)
In response to the urgent call for investigations into antiretroviral (ARV)-African traditional medicine (ATM) interactions, this research was undertaken to ascertain whether chronic administration of the ATM, Sutherlandia frutescens (SF) may alter the bioavailability of the protease inhibitor (PI), atazanavir (ATV), which may impact on the safety or efficacy of the ARV. Prior to investigating a potential interaction between ATV and SF in vitro and in vivo, a high performance liquid chromatography method with ultraviolet detection (HPLC-UV) was developed and validated for the bioanalysis of ATV in human plasma and liver microsomes. An improved and efficient analytical method with minimal use of solvents and short run time was achieved in comparison to methods published in the literature. In addition, the method was selective, linear, accurate and precise for quantitative analysis of ATV in these studies. Molecular docking studies were conducted to compare the binding modes and affinities of ATV and two major SF constituents, Sutherlandioside B and Sutherlandin C, with the efflux transporter, P-glycoprotein (P-gp) and the CYP450 isoenzyme, CYP3A4 to determine the potential for these phytochemicals to competitively inhibit the binding of ATV to these two proteins, which are mediators of absorption and metabolism. These studies revealed that modulation of P-gp transport of ATV by Sutherlandioside B and Sutherlandin C was not likely to occur via competitive inhibition. The results further indicated that weak competitive inhibition of CYP3A4 may possibly occur in the presence of either of these two SF constituents. The Caco-2 cell line was used as an in vitro model of human intestinal absorption. Accumulation studies in these cells were conducted to ascertain whether extracts and constituents of SF have the ability to alter the absorption of ATV. The results showed that the aqueous extract of SF significantly reduced ATV accumulation, suggesting decreased ATV absorption, whilst a triterpenoid glycoside fraction isolated from SF exhibited an opposing effect. Analogous responses were elicited by the aqueous extract and a triterpenoid glycoside fraction in similar accumulation studies in P-gp overexpressing Madin–Darby Canine Kidney Strain II cells (MDCKII-MDR1), which signified that the effects of this extract and component on ATV transport in the Caco-2 cells were P-gp-mediated. The quantitative analysis of ATV in human liver microsomes after co-incubation with extracts and components of SF was conducted to determine the effects of SF on the metabolism of ATV. The aqueous and methanolic extracts of SF inhibited ATV metabolism, whilst the triterpenoid glycoside fraction had a converse effect. Analogous effects by the extracts were demonstrated in experiments conducted in CYP3A4-transfected microsomes, suggesting that the inhibition of ATV metabolism in the liver microsomes by these SF extracts was CYP3A4-mediated. A combination of Sutherlandiosides C and D also inhibited CYP3A4-mediated ATV metabolism, which was in contrast to the response elicited by the triterpenoid fraction in the liver microsomes, where other unidentified compounds, shown to be present therein, may have contributed to the activation of ATV metabolism. The in vitro studies revealed the potential for SF to alter the bioavailability of ATV, therefore a clinical study in which the effect of a multiple dose regimen of SF on the pharmacokinetics (PK) of a single dose of ATV was conducted in healthy male volunteers. The statistical analysis showed that the 90 % confidence intervals around the geometric mean ratios (ATV + SF/ATV alone) for both Cmax and AUC0-24 hours, fell well below the lower limit of the "no-effect" boundary of 0.8 – 1.25, implying that the bioavailability of ATV was significantly reduced in this cohort of subjects. It may thus be concluded that if the reduction in bioavailability observed in this clinical study is found to be clinically relevant, co-administration of SF commercial dosage forms and ATV in HIV/AIDS patients may potentially result in subtherapeutic ATV levels, which may in turn contribute to ATV resistance and/or treatment failure. This research has therefore highlighted the potential risk for toxicity or lack of efficacy of ARV regimens which may result when ATMs and PIs are used concurrently and that patients and health care practitioners alike should be aware of these perils.
743

Structural analysis of effects of mutations on HIV-1 subtype C protease active site

Mathu, Alexander Muchugia Nganga January 2012 (has links)
HIV/AIDS is a global pandemic that poses a great threat especially in Sub-Saharan Africa where the highest population of those infected with the virus is found. It has far reaching medical, socio-economic and scientific implications. The HIV-1 protease enzyme is a prime therapeutic target that has been exploited in an effort to reduce morbidity and mortality. However problems arise from drug toxicity and drug-resistant mutations of the protease which is a motivation for research for new, safer and effective therapies. Evidence exists to show that there are significant genomic differences in Subtype B and C that have a negative effect on the intrinsic binding of inhibitors. It is imperative to look at all perspectives from epidemiological, molecular to the pharmacological ones so as to achieve rational design of therapeutic agents. This study involved the use of in silico structural analysis of the effects of mutations in the active site. The data was provided by the National Institute of Communicable Diseases consisting of HIV-1 Subtype C protease sequences of 29 infants exhibiting drug-resistance to ritonavir and lopinavir. The major active site mutations causing drug resistance identified in this study were M46I, I54V and V82A using the Stanford HIV database tool. Homology modeling without extra restraints produced models with improved quality in comparison to those with restraints. MetaMQAPII results differed when models were visualized as dimers giving erroneous modeled regions in comparison to monomers. A broader study with a larger dataset of HIV-1 subtype C protease sequences is required to increase statistical confidence and in order to identify the pattern of drug resistant mutations. Homology modeling without extra restraints is preferred for calculating homology models for the HIV-1 subtype C. Further investigations needs to be done to ascertain the accuracy of validation results for dimers from MetaMQAPII as it is designed for evaluation of monomers.
744

An in-silico investigation of Morita-Baylis-Hillman accessible heterocyclic analogues for applications as novel HIV-1 C protease inhibitors

Sigauke, Lester Takunda January 2015 (has links)
Cheminformatic approaches have been employed to optimize the bis-coumarin scaffold identified by Onywera et al. (2012) as a potential hit against the protease HIV-1 protein. The Open Babel library of commands was used to access functions that were incorporated into a markov chain recursive program that generated 17750 analogues of the bis-coumarin scaffold. The Morita-Baylis-Hillman accessible heterocycles were used to introduce structural diversity within the virtual library. In silico high through-put virtual screening using AutoDock Vina was used to rapidly screen the virtual library ligand set against 61 protease models built by Onywera et al. (2012). CheS-Mapper computed a principle component analysis of the compounds based on 13 selected chemical descriptors. The compounds were plotted against the principle component analysis within a 3 dimensional chemical space in order to inspect the diversity of the virtual library. The physicochemical properties and binding affinities were used to identify the top 3 performing ligands. ACPYPE was used to inspect the constitutional properties and eliminated virtual compounds that possessed open valences. Chromene based ligand 805 and ligand 6610 were selected as the lead candidates from the high-throughput virtual screening procedure we employed. Molecular dynamic simulations of the lead candidates performed for 5 ns allowed the stability of the ligand protein complexes with protease model 305152. The free energy of binding of the leads with protease model 305152 was computed over the first 50 ps of simulation using the molecular mechanics Poisson-Boltzmann method. Analysis structural features and energy profiles from molecular dynamic simulations of the protein–ligand complexes indicated that although ligand 805 had a weaker binding affinity in terms of docking, it outperformed ligand 6610 in terms of complex stability and free energy of binding. Medicinal chemistry approaches will be used to optimize the lead candidates before their analogues will be synthesized and assayed for in vivo protease activity.
745

Structural studies on yeast eIF5A using biomolecular NMR and molecular dynamics

Sigauke, Lester Takunda January 2015 (has links)
Eukaryotic initiation factor 5A, eIF5A, is a ubiquitous eukaryotic protein that has been shown to influence the translation initiation of a specific subset of mRNAs. It is the only protein known to undergo hypusination in a two-step post translational modification process involving deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH) enzymes. Hypusination has been shown to influence translation of HIV-1 and HTLV-1 nuclear export signals, while the involvement of active hypusinated eIF5A in induction of IRES mediated processes that initiate pro-apoptotic process have inspired studies into the manipulation of eIF5A in anti-cancer and anti-diabetic therapies. eIF5A oligomerisation in eukaryotic systems has been shown to be influenced by hypusination and the mechanism of dimerisation is RNA dependent. Nuclear magnetic resonance spectroscopy approaches were proposed to solve the structure of the hypusinated eIF5A in solution in order to understand the influence of hypusination on the monomeric arrangement which enhances dimerisation and activates the protein. Cleavage of the 18 kDa protein monomer by introduction of thrombin cleavage site within the flexible domain was thought to give rise to 10 kDa fragments accessible to a 600 MHz NMR spectrometer. Heteronuclear single quantum correlation experiments of the mutated isotopically labelled protein expressed in E. coli showed that the eIF5A protein with a thrombin cleavage insert, eIF5AThr (eIF5A subscript Thr), was unfolded. In silico investigations of the behaviour of eIF5A and eIF5AThr (eIF5A subscript Thr) models in solution using molecular dynamics showed that the mutated model had different solution dynamics to the native model. Chemical shift predictors were used to extract atomic resolution data of solution dynamics and the introduction of rigidity in the flexible loop region of eIF5A affected solution behaviour consistent with lack of in vivo function of eIF5AThr (eIF5A subscript Thr) in yeast. Residual dipolar coupling and T₁ relaxation times were calculated in anticipation of the extraction of experimental data from RDC and relaxation dispersion experiments based on HSQC measurable restraints.
746

An investigation into the management of HIV/AIDS programmes at the workplace in a highly volatile environment: a case study of selected organisations in Harare, Zimbabwe

Nyemba, Taurai Booth William January 2008 (has links)
The HIV/AIDS pandemic has had a devastating effect in the world, as it is now rated as the world’s greatest killer since its appearance in the mid 1980s. A UNICEF Report (2005) states that sub Saharan Africa is the hardest hit with countries like Botswana, Zimbabwe, South Africa, Namibia and Mozambique having an average of one in every five adults being infected. Sub Saharan Africa has less than 3 percent of the world’s population but it has an estimated 65 percent of the world’s population living with HIV/AIDS as it has 26 million of the 40 million infected people worldwide. In May 2003 the Government of Zimbabwe declared HIV/AIDS a national emergency a move that seems to have yielded results as the HIV prevalence rate has come down from 26.1 percent to 18.6 percent in 2005 and further to 15.6 percent in 2007. The Ministry of Health and Child Welfare (2004) states that if the prevalence had continued at 26.1 percent, about two thirds of today’s 15- year-olds would die from this disease. The deterioration of the political, social and economic situation since 1999 and the withdrawal of donor development support due to policy differences require concerted efforts from all parties concerned, now, rather than later. More commitment must be shown by private and public sector organisations to active participation in the establishing of effective workplace programmes, to assist employees, for the pandemic has placed a heavy strain on the health delivery system, as AIDS patients occupy between 50 percent to 70 percent of all hospital beds. Furthermore, the pandemic is killing the youth at the prime of their working careers so the pandemic, while being a health problem also has a negative macro-economic impact which may lead to a developmental crisis. A study was conducted of six organisations, using two questionnaires, one for management and one for non-management level employees. The study investigates whether the organisations had HIV/AIDS programmes and whether such programmes were effective. The findings were that all six organisations had HIV/AIDS programmes in place. However, some of the programmes were not effective because the employees did not know of their existence. Furthermore, it was found that management initiated awareness programmes and made condoms available but the employees were not changing their risky behaviour.
747

Assessment of knowledge, attitudes and utilisation of HIV post-exposure prophylaxis among adults, Roma, Lesotho

Lebona, Maselobe Anna 11 1900 (has links)
As the Human Immunodeficiency Virus (HIV) prevalence rises, uninfected Basotho face an increased risk of exposure. This necessitates strengthening of strategies that prevent exposure, and where exposure has occurred, measures that prevent infection. One such measure is Human Immunodeficiency Virus (HIV) Post-Exposure Prophylaxis (PEP). Awareness and knowledge of HIV PEP is therefore of paramount importance. The purpose of this study was to assess knowledge, attitudes and utilisation of HIV PEP among adults in Roma, Lesotho. A quantitative cross-sectional study was conducted among 96 adult outpatients at St Joseph’s Hospital. Data were collected by means of structured questionnaire and analysed using SPSS version 23.0. Results were presented using charts and tables. Awareness of HIV PEP among the respondents was found to be very low and for most respondents’ knowledge of HIV PEP was either non-existent or very poor. Utilisation was also found to be very low. Attitudes towards HIV PEP were, however, found to be favourable. More studies should be conducted throughout the country to further explore Basotho’s knowledge, attitude and use of HIV PEP. / Health Studies / M.A. (Nursing Science)
748

Exploiting the use of induced pluripotent stem cell derived immune cells for immunotherapy

Sachamitr, Supatra January 2015 (has links)
Immunotherapy traditionally made use of biological agents such as cytokines and monoclonal antibodies. Such first generation therapies lack antigen specificity and fail to induce immunological memory, suggesting that cell therapies may provide the next generation of treatments that are more discerning in their mode of action. Nevertheless, difficulties in obtaining sufficient immunologically-relevant cell types from patients has limited their success. Given that induced pluripotent stem cells (iPSC) may be generated from patients, we have investigated the feasibility of deriving two cell types whose availability is restricted in vivo: regulatory T cells (T<sub>regs</sub>) and CD141<sup>+</sup> cross-presenting dendritic cells (DCs). We describe the optimization of protocols for differentiation and purification of CD141<sup>+</sup> DCs, focussing on their utility as a therapeutic vaccine for HIV-1. We investigate their phenotype, chemotactic capacity, phagocytic ability and propensity to harbour infectious virus. We also assess their immunostimulatory capacity and ability to cross-present exogenous antigen to MHC class I-restricted T cells. Our findings led us to speculate that iPSC-derived DCs (iPDCs) possess fetal phenotype, which is characterised by excessive secretion of IL-10 and failure to secrete IL-12, under all but the most stringent conditions. We hypothesised that constitutive secretion of IL-10 may be responsible for maintaining the fetal phenotype, a hypothesis we tested by developing an appropriate mouse model. iPSCs were derived from WT and IL-10<sup>-/-</sup> mice and were shown to differentiate into iPDCs which recapitulate the fetal phenotype observed among human cells. However, loss of the endogenous Il-10 gene failed to restore full immunogenicity and IL-12 secretion. Finally, we developed protocols for differentiation of FoxP3+ T<sub>regs</sub> from iPSCs, a feat that has not previously been achieved. These findings pave the way for the differentiation of T<sub>regs</sub> from iPSCs reprogrammed from antigen-specific pathogenic T cells, thereby creating a source of T<sub>regs</sub> with matched specificity for therapeutic intervention.
749

Influence of the home environment on prevention of mother to child transmission (PMTCT) of HIV/AIDS

Sewnunan, Asha 28 March 2014 (has links)
This study aimed at exploring the influence of the home environment of women that were on the prevention of mother-to-child transmission (PMTCT) programme for HIV/AIDS. A qualitative descriptive study was conducted to explore the home environment for the psycho-social support that was available for women on the PMTCT programme and the influence this had on compliance to the programme. Data collection was done using a semi-structured interview guide, with a sample size of 14 participants (n=14). The data was then coded and grouped into categories and major themes. The findings revealed that the common barriers that prevented full disclosure of an HIV positive status included stigma and discrimination, fear of social isolation and financial dependence. A major constraint that affected the women’s full utilisation of the PMTCT preventative strategies and their adherence to treatment was the poor acceptance of people living with HIV in the family and community / Health Studies / M.A. (Health Studies)
750

An evaluation of fetal growth in human immunodeficiency virus infected women at Khayelitsha and Gugulethu midwifery obstetric units in the Western Cape

Isaacs, Ferial January 2006 (has links)
Thesis (MTech (Radiography))--Cape Peninsula University of Technology, 2006 / A prospective cohort study was done on Human Immunodeficiency Virus (HIV) infected and uninfected women attending Khayelitsha Midwifery Obstetric Unit (MOU) and Gugulethu MOU from June 2003 to December 2004, primarily to establish whether there is an association between HIV infection and Intra-uterine growth restriction (lUGR). B-Mode real time ultrasound imaging was used to monitor fetal growth from ±22 weeks to 36 weeks gestational age. Birth weight, gestational age at delivery, gender, placental weight, and maternal complications were also included. Maternal factors considered included age, weight parity, singleton versus multiple pregnancy, previous IUGR or preterm delivery, previous fetal abnormality, social habits viz. cigarette smoking, alcohol and drug use, and vascular disease viz. Diabetes, hypertension, renal disease, cardiac disease and collagen disease. A secondary objective was to establish whether the CD4 T-lymphocyte count possibly modulated the presence of IUGR. All HIV infected women were given antiretroviral therapy according to the standard Protocol of the Provincial Government of Western Cape (2002). The research questions were: • Does maternal HIV infection increase the risk of intrauterine growth restriction and associated preterm delivery? • Does the immune status of (CD4 T-lymphocyte count) of HIV infected pregnant women modulate fetal growth? The primary objective of this study was to establish whether there is an association between HIV infection and IUGR, and hence that HIV infection leads to an adverse perinatal outcome. Ultrasound was used as a diagnostic tool to establish normal or abnormal fetal growth patterns. Anecdotal reports from health workers in the obstetric field suggested that IUGR and preterm delivery may be associated with low birth weight infants in HIV infected pregnant women. However, preterm delivery is associated with various other factors including low socio-economic status (poor nutrition), cigarette smoking, drug and alcohol abuse, previous history of preterm delivery, over distention of the uterus (hydramnios, multiple gestation), premature rupture of membranes, cervical incompetence, vaginal infections (bacterial vaginosis) and maternal disease e.g. hypertension, heart disease (Lizzi, 1993: Symmonds, 1992; Odendaal et aI, 2002). HIV is now thought to be an added factor. Afier doing a systematic review and meta-analysis of 31 studies, Brocklehurst and French (1998) reported that there is an association (although not strong) between HIV infection and adverse perinatal outcome in developed countries; but in developing countries, there is an increased risk of infant death. By excluding or controlling for confounding variables that could affect fetal growth, this study aimed to determine whether there is a significant association between HIV and fetal growth by comparing fetal growth in HIV infected and uninfected women from midsecond trimester to the time of delivery. A secondary objective was to establish whether there is an association between the immune status (CD4 T-lymphocyte count) of the mother and IUGR. The immune status of the mother is probably one of the most important factors affecting the fetus and perinatal outcome. As the mother's viral load increases, her immune system is increasingly compromised, resulting in the occurrence of HIV-related diseases, and a concurrent increase in fetal complications. In this study a CD4 T-lymphocyte count was used to assess the level of immunodeficiency of all the HIV infected participants. Ideally the test should have been done each time the participant was scanned so that the CD4 T-lymphoc)1e count could be monitored simultaneously with the fetal growth parameters, however due to financial constraints and ethical considerations, one test was done on each HIV infected women. This study was based at two MOU's where different antiretroviral therapy (ARVT) regimens were used. The one MOU offered Zidovudine (ZDV) to mothers from 34 weeks gestation to the onset of labour, and the other MOU offered Nevirapine (NVP) as a single dose to the mother at the onset of labour and to the neonate within 72 hours of birth (Provincial Government Western Cape, 2002). This presented an opportunity to compare two groups of HIV infected women on different regimes. The intention was to establish whether ZDV had an adverse effect on fetal growth and resulted in low birth weight. However, 6 months after the study started a revised Prevention of Mother to Child Transmission (PMTCT) Protocol was implemented where women at both MOU's received the same ARVT i.e. ZDV and NVP. This objective was therefore abandoned due to a change in the PMTCT Protocol in the Western Cape. The study was based at two Midwife Obstetric Units (MOU) in the Western Cape where the prevalence of HIV in pregnant women is relatively high i.e. 20 - 24 % (Mother-to-child transmission Monitoring Team, 2001), viz. Gugulethu MOU and Khayelitsha MOU. A prospective cohort study was done with the intention of recruiting a sample of 400 pregnant women, 200 HIV infected and 200 uninfected. The actual sample size was 415. The study group was 194 HIV infected women and the control group was 221 uninfected women. Confounding variables such as cigarette smoking, alcohol and drug abuse. multiple gestation. grand multipara pregnancy, history of IUGR or preterm delivery. fetal abnormality detected at the time of the first scan in the current pregnancy, and maternal vascular disease - were excluded. Confounding variables such as maternal age, maternal weight and gestational age were controlled. Ultrasound imaging was used as a diagnostic tool to establish normal and abnormal fetal growth patterns. A B-mode real time ultrasound unit was used to confirm the gestation age and rule out any obvious fetal abnormalities at 20-24 weeks gestation. Fetal growth scans were done at 28 weeks, 32 weeks and 36 weeks gestation to compare fetal growth patterns in the study and control groups. Fetal biometry used to monitor fetal growth included biparietal diameter (BPD), head circumference (HC), femur length (FL), abdominal circumference (AC) and estimated fetal weight (EFW). Amniotic fluid index (AFI), placental thickness & placental grading were also included. The following variables were analyzed post delivery: • Gestation age at delivery: Normal term delivery is considered to be at 37 - 42 weeks and premature delivery is considered to be less than 37 weeks gestation. The HIV infected and uninfected groups were compared to assess if there \vas a significant difference in the number of preterm deliveries. • Birth weight: The HIV infected and uninfected groups were compared to assess if there was a significant difference in the number of infants with low birth weight. • Perinatal complications: The HIV infected and uninfected groups were compared to assess if there was a significant difference in the number of perinatal complications and to assess if there was an association between the immune status (CD4 T-lymphocyte count) of HIV infected women and perinatal complications. Appropriate ethical principles in medical research were applied. The participant's autonomy, rights and best interests were always considered a priority. Informed consent was obtained from all the participants. Strict confidentiality was adhered to regarding any data collected throughout the study. The Research Ethics Committees at Cape Peninsula University of Technology and University of Cape Town granted ethics approval for the study. Statistical analysis was performed using the statistical package SPSS 12.0.

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