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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.
121

Tissue Compartmentalization and Tropism of HIV-1: A Dissertation

Brese, Robin L. 10 August 2016 (has links)
Despite the development of effective antiretroviral treatments, there is still no cure for HIV-1. Major barriers to HIV-1 eradication include the diversity of intrapatient viral quasispecies and the establishment of reservoirs in tissue sanctuary sites. A better understanding of these populations is required for targeted treatments. While previous studies have examined the relationship between brain and blood or immune tissues, few have looked at and compared the properties of viruses from other tissue compartments. In this study, 75 full length HIV-1 envelopes were isolated from the frontal lobe, occipital lobe, parietal lobe, colon, lung, and lymph node of an HIV-1 infected subject. No envelopes could be amplified from the plasma or serum. Envelopes were subjected to genotypic and phenotypic characterization. Of the 75 envelopes, 53 were able to infect HeLa TZM-bl cells. The greatest proportion of non-functional envelopes was from the lung, a result of APOBEC-induced hypermutation. Lower frequencies of hypermutation were also observed in the occipital lobe and colon. Envelopes from regions of the brain were almost all macrophage tropic, while those from the body were predominantly non-macrophage tropic. All envelopes used CCR5 as a coreceptor. Phylogenetic analyses showed that sequences were compartmentalized inside the brain. These findings were also observed using PacBio next generation sequencing to examine 32,152 full length sequences. Envelopes from tissues of the body displayed greater variation in sequence length, charge, and number of potential N-linked glycosylation sites in comparison to envelopes from tissues of the brain. Increased variation was also observed in IC50s for inhibition and neutralization assays using sCD4, maraviroc, b12, PG16, 17b, and 447-52D. The increased variation observed in envelopes from tissues outside the brain suggests that different pressures may be influencing the evolution of these viruses and emphasizes the importance of further studies in these tissue sites.
122

FC Receptor-Mediated Activities of Env-Specific Monoclonal Antibodies Generated from Human Volunteers Receiving a DNA Prime-Protein Boost HIV Vaccine: A Dissertation

Costa, Matthew R. 12 October 2016 (has links)
Human immunodeficiency type 1 (HIV-1) is able to elicit broadly potent neutralizing antibodies in a very small subset of individuals only after several years’ infection and as a result, vaccines that elicit these types of antibodies have been difficult to design. The RV144 trial showed that a moderate protection is possible, which may correlate with antibody dependent cellular cytotoxicity (ADCC) activity. Previous studies in the Lu lab demonstrated that in an HIV-1 vaccine phase I trial, DP6-001, a polyvalent Env DNA prime-protein boost formulation, could elicit potent and broadly reactive, gp120-specific antibodies with positive neutralization activities along with multiple Fc mediated effector functions. I developed a protocol for the production and analysis of HIV-1 Env-specific human monoclonal antibodies (mAbs) isolated from these DP6-001 vaccinees. By utilizing a labeled gp120 bait to isolate Env specific B cells, paired heavy and light chain immunoglobulin (Ig) genes were cloned and allowed for the production of monoclonal antibodies with specificity for gp120. By using this protocol, 13 isolated mAbs from four DP6-001 vaccinees showed broad binding activities to gp120 proteins of diverse subtypes, both autologous and heterologous to vaccine immunogens, with mostly conformational epitopes and a few V3 and C5 specific mAbs. Equally cross-reactive Fc-mediated functional activities, including ADCC and antibody dependent cellular phagocytosis (ADCP), were present with both immune sera and isolated mAbs, confirming the induction of non-neutralizing functional antibodies by the DNA prime- protein boost vaccination. Elicitation of broadly reactive mAbs by vaccination in healthy human volunteers confirms the value of the polyvalent formulation in this HIV-1 vaccine design.
123

Perceptions of risk of human immunodeficiency virus infection among students in the Institute of Development Management, Gaborone, Botswana Campus

Malefho, Kegomoditswe M. January 2022 (has links)
Thesis (MPH.) -- University of Limpopo, 2022 / Background: Acquired Immunodeficiency Syndrome still remains the leading cause of death globally. Understanding students’ views about the risk of Human Immunodeficiency Virus infection by exploring and describing their perceptions may help to design effective Human Immunodeficiency Virus prevention interventions. The tertiary institution environment offers a great opportunity for Human Immunodeficiency Virus high risk behaviours, including alcohol and drug abuse, unsafe sex, multiple sexual relationships, intergenerational and transactional sex. Despite the decline in the overall incidence of Human Immunodeficiency Virus infection, still a significant proportion of the youth population are at risk of Human Immunodeficiency Virus infection. Objectives: The study was to explore and describe perception of risk of Human Immunodeficiency Virus among students at the Institute of Development Management, Gaborone, Botswana Campus. Methodology: A qualitative, exploratory, descriptive study using semi-structured interviews with purposively selected second year Public Health students was conducted. Interviews were conducted using an interview guide. It was audio recorded until data saturation was reached, where eight students participated in the study. Voice recordings were transcribed verbatim and analysed thematically. Results: The findings reveals that some participants perceive themselves to be at risk of contracting Human Immunodeficiency Virus, while others perceive themselves as being not at risk of Human Immunodeficiency Virus infection. Several risk factors associated with Human Immunodeficiency Virus infection, for example, alcohol and drug abuse, multiple concurrent sexual relationships, intergenerational and transactional sex are revealed as challenges. They also expressed their fears in relation to Human Immunodefiency Virus testing, pregnancy and disclosure of Human Immunodeficiency Virus positive status due to the stigma and discrimination. Conclusion: High risk behaviours leading to Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome prevalence are still common among young people, hence the need for government and all stakeholders to specifically address them by coming up with specific behavioural intervention programmes.
124

Formulation and evaluation of polymeric micelles for improved oral delivery of tenofovir disoproxil fumarate and zidovudine using poly-lactic-co-glycolic acid nanoparticles

Tenghe, Lovette Asobo January 2018 (has links)
Magister Pharmaceuticae - MPharm / Background: Tenofovir disoproxil fumarate (TDF) and Zidovudine (AZT) are both nucleotide and nucleoside analogue reverse transcriptase inhibitors (NtRTIs and NRTIs), respectively. They are used for the management and prevention of the Human Immunodeficiency Virus (HIV) infection. These drugs are faced with oral delivery challenges such as low intestinal permeability and extensive first pass liver metabolism for TDF and AZT, respectively. Their use may also be limited by dose-dependent adverse effects, which may result in treatment failure when patients become non-compliant and non-adherent to their prescribed antiretroviral (ARV) regimen. Non-compliance and non-adherence to ARV regimen may lead to drug resistance and a need for change in regimen, which can be very expensive, not only financially but in terms of morbidity and mortality. To solve such issues, a new drug can be formulated, or an existing drug can be modified. The development and formulation of a new drug is time consuming and expensive, especially with no available data and a high probability of failure. Modifying existing drugs is a cheaper, less time-consuming option with lower probability of failure. Such modification can be achieved via non-covalent interactions using various methods such as preparation of nano-particulates with polymeric micelles (a non-covalent interaction). Polymeric micelles offer a variety of polymers to choose from for drug modification purposes. Purpose: The aim of this study was to formulate polymeric nanoparticles of TDF and AZT using different ratios of poly-lactic-co-glycolic acid (PLGA), characterize the formulated nanoparticles (using the following analyses: particle size, zeta potential, encapsulation efficiency, hot stage microscopy, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy and scanning electron microscopy), analyze for stability during storage (2-8˚C) and determine the release rate of the active pharmaceutical ingredients in the formulated nanoparticles. Methods: Nanoparticles were prepared using a modified version of the double emulsion (water-in-oil-in-water) solvent evaporation and diffusion method. Two ratios of PLGA (50:50 and 85:15) were used to prepare four formulations (two each of TDF and AZT). Thereafter, the physicochemical and pharmaceutical properties of the formulations were assessed by characterizing the nanoparticles for particle size, zeta potential, polydispersity index, percentage yield, release profile and particle morphology, using the suggested analytical techniques. Results: For TDF-PLGA 85:15, TDF-PLGA 50:50, AZT-PLGA 85:15 and AZT-PLGA 50:50, nanoparticles of 160.4±1.7 nm,154.3±3.1 nm,127.0±2.32 nm and 153.2±4.3 nm, respectively, were recovered after washing. The polydispersity index (PDI) values were ≤0.418±0.004 after washing, indicating that the formulations were monodispersed. The zeta potential of the particles was -5.72±1 mV, -19.1 mV, -12.2±0.6 mV and -15.3±0.5 mV for TDF-PLGA 85:15, TDF-PLGA 50:50, AZT-PLGA 85:15 and AZT-PLGA 50:50 respectively after washing. The highest percentage yield was calculated to be 79.14% and the highest encapsulation efficiency obtained was 73.82% for AZT-PLGA 50:50, while the particle morphology showed spherical nanoparticles with signs of coalescence and aggregation for all formulated nanoparticles. The release profiles were biphasic; that is, an initial burst which indicated the presence of surface API followed by sustained release. Comparing the release profiles of AZT and TDF at pH 1.2 and 7.4, it was indicative that more AZT was released at pH 1.2 while more TDF was released at pH 7.4. On computing the release data further into various mathematical models, the Weibull model was found to be the best fit. The loaded nanoparticles showed an increase in stability after washing; however, they showed signs of gradual decrease in stability after 10 days of storage at 2-8°C. Conclusions: Relatively small, spherical and smooth nanoparticles were formulated. The nanoparticle release profile was indicative of sustained release; however, there was no conclusive indication that 48 hours duration was sufficient to release all encapsulated drug. Further studies with an increased API or polymer ratio in the formulation needs to be performed to determine if the encapsulation efficiency can be improved and in-vivo studies are required for a better understanding of the API release from formulations as well as its absorption in the body.
125

Knowledge levels of voluntary counselling and testing for human immunodeficiency virus amoungst taxi drivers in Kampala, Uganda

Kizito, Assisi-Franklin 28 February 2007 (has links)
Student Number : 0312394F - MPH research report - School of Public Health - Faculty of Health Sciences / Introduction: Human Immunodeficiency Virus (HIV) was first isolated from human blood in 1983 at the Pasteur Institute, Paris. Currently there is no cure for HIV and control efforts emphasize prevention. One of the components of the Global Strategy put forward to preventing HIV transmission is HIV Voluntary Counselling and Testing (VCT) (Ginwalla, Grant & Day:2002). Taxi drivers are part of the Ugandan population at special risk of acquiring this virus. It was therefore necessary to carry out a study in this group of people to assess how much they knew about HIV/VCT services. Study Objectives To establish the level of knowledge amongst the taxi drivers about the availability and accessibility of HIV VCT services in Kampala. To identify factors that influence the taxi drivers in Kampala, Uganda to access the VCT services. Methods and materials A cross-sectional descriptive study design was used to carry out the study amongst 400 taxi drivers who consented to participate and operated within and around the city of Kampala during 2004. A structured questionnaire to record variables that included, age, sex, marital status, level of education, level of knowledge of VCT, factors that enhance VCT uptake, factors that inhibit VCT uptake, history of having ever had VCT, and knowledge of spouse or sexual partner’s HIV serostatus, was used. Data was entered into EPI-INFO 6 computer program and descriptive and analytic investigation using proportion or percentages to compare the level of knowledge generated was used. Findings/Results A total of 399 taxi drivers with 52.8% of them aged between 26 – 35 years participated in the study. 68.8% lived within 6 km of the city centre. All were married and 78.8% had one spouse. 0.75% were lady drivers. 55% of the participants had attained secondary school level of education. 69% of the taxi drivers knew that HIV/AIDS was the commonest health problem in the country and 57.4% of the participants mentioned HIV testing as the only way one would ascertain their serostatus. 94.2% had heard about HIV/VCT mainly from the media and as much as 98.7% of the taxi drivers knew a place where such services could be got. 82.2% confirmed that these places were accessible and 85.9% said that the services were not expensive. However, 57.3% of the participants preferred getting these services where they were known in order to get genuine results and subsequent support. The 26% who opposed this idea sighted confidentiality as the main obstacle. Despite the knowledge level about HIV/VCT amongst the participants, 68.3% of the communal taxi drivers were willing to go for the service and only 16.1% had actually taken the test. Out of the 399 participants 59.6% felt that they could share their serostatus with their spouses. Conclusion The taxi drivers are knowledgeable about HIV/VCT services and these findings lie within the overall range of knowledge of the population in urban Uganda. The HIV/VCT services are accessible and affordable to the taxi drivers but the fear to receive the unexpected results and the consequences of having positive results hinder the taxi drivers from seeking the VCT services. The majority of taxi drivers preferred to go to HIV/VCT service points where they were known. This factor could have contributed to the small number of taxi drivers that had taken the test. Probably few suitable service points to go to had been identified by these taxi drivers. Recommendations The government and other organizations that provide care in the field of HIV should organize sensitization seminars for taxi drivers to address issues aimed at allaying their anxiety or fear to receive positive results. Also, there is a need to intensify counselling services for the taxi drivers by establishing counselling centres close to the two taxi parks in the City. HIV/VCT service centres should be integrated with other health services so that people who seek either of the services can gain from both. This will encourage more taxi drivers to come to these centres.
126

Compaixão na contratransferência: cuidado emocional a jovens HIV+(s)

Mencarelli, Vera Lúcia 26 April 2010 (has links)
O presente estudo consiste na investigação psicanalítica das configurações assumidas pelo campo contratransferencial que se estabelece no atendimento psicológico, psicanaliticamente orientado, de pacientes soropositivos para o HIV. Quatro adolescentes, soropositivos em decorrência de transmissão vertical, foram psicanaliticamente assistidos por meio de diferentes enquadres clínicos, que incluíram sessões de psicoterapia individual, oficinas psicoterapêuticas e atividades extramuros, segundo a demanda. Esse complexo acontecer clínico deu origem à elaboração de quatro narrativas transferenciais, que foram psicanaliticamente revisitadas, na busca de criação/encontro de campos contratransferenciais. O quadro geral permite afirmar que, para além de ressonâncias contratransferenciais associadas a peculiaridades relativas ao adolescer e às vicissitudes das histórias individuais, é possível detectar a vigência de um campo contratransferencial nitidamente caracterizado pela compaixão. Tal configuração suscita reflexões teórico-clínicas que apontam que tanto as questões ontológicas relativas à precariedade, limitação e finitude, como as decorrentes das condições concretas de vida, tais como o adoecimento, a experiência da dor, o severo tratamento, a orfandade e a exclusão social, devem ser profundamente levadas em conta no cuidado a esses pacientes / This study aims to show the psychoanalytical investigation of the settings assumed by the countertransference field, which is established in psychological sessions, psychoanalytically oriented, in patients infected with HIV. Four teenagers, positives for HIV by vertical transmission, were psychoanalytically assisted by different clinical setting, which included individual psychotherapy sessions, psychotherapeutic workshops and outdoors activities, according to demand. This complex clinical case originates the development of four transference narratives, which were psychoanalytically revisited, in search of the creation/gathering of countertransference fields. The overall clinical picture allows us to state that, beyond the countertransference resonances associated to peculiarities related to adolescence and to the vicissitude of individual stories, is possible to detect the presence of a countertransference field clearly characterized by compassion. This configuration suscitate theoretical-clinical reflections that point out that the ontological issues caused by precariousness, limitation and finitude, as the current real life conditions, such as illness, experience of pain, severe treatment, the orphanhood and the social exclusion, must be thoroughly considered in the care of these patients
127

Von Willlebrand Factor cleaving protease levels in patients with HIV related thrombocytopenia

Garizio, Dominique Gilda 11 February 2009 (has links)
Abstract Background: Deficiency of Von Willebrand Factor Cleaving Protease (VWFCP) has been implicated as the cause of Thrombotic Thrombocytopenic Purpura (TTP). TTP is a lifethreatening disease characterised by microangiopathic thrombosis due to accumulation of Ultralarge Von Willebrand Factor (ULVWF) multimers. The clinical features of TTP include microangiopathic haemolysis and thrombocytopenia. TTP is being seen with increased frequency in the context of HIV. However, in the context of HIV infection, cytopenias are often multifactorial in nature and levels of VWFCP in HIV-related thrombocytopenia have not specifically been assessed. This study assessed VWFCP activity in the setting of patients with HIV and thrombocytopenia in the absence of TTP, in order to determine the utility of a VWFCP assay in the diagnosis of HIV-related TTP. Acquired VWFCP deficiency is generally assumed to be due to the presence of autoantibody inhibitors to the enzyme, but limited data are available regarding VWFCP activity in HIV positive TTP patients. There is also currently no assay available for measuring VWFCP activity in our laboratory. Aim of Study: To establish a practical assay for VWFCP activity for routine use in our laboratory. The rapid collagen binding assay, based on the ELISA method of Rick, et al., 2002, was chosen. This was initially used to measure VWFCP activity in patients with HIV with and without thrombocytopenia (of any cause except TTP), in order to ascertain whether assessment of VWFCP activity is likely to be of value in facilitating early diagnosis of HIV related TTP. The ELISA assay was performed to establish cut-off values for VWFCP in HIV negative controls and two HIV positive groups (HIV thrombocytopenia / low platelets and HIV normal platelets). Depending on the outcome of this, the assay could then be performed to assess VWFCP activity in HIV positive patients with TTP. Methods: The rapid collagen binding assay for VWFCP activity was established and optimised for routine use in our laboratory. The cut-off values for percentage Residual Collagen Binding Activity (RCBA) in both HIV negative and HIV positive groups were identified. The assay could then be used to assess VWFCP activity in 20 HIV positive patients with TTP at the time of presentation. In patients with reduced VWFCP activity, patient plasma was mixed with normal pool plasma in a 50:50 mix, to assess for the presence of inhibitors. Correlation of VWFCP activity, inhibitors and other laboratory and clinical parameters were performed. Results: The cut-off values for percentage RCBA in both HIV negative (<37.12%) and HIV positive (<51.51%) patients were established. The % RCBA for the HIV negative control group was statistically significantly different from the HIV positive group with normal platelets (p=0.0001) and from the HIV positive group with low platelets (p=0.0006). The cut-off value in the two HIV positive patient groups was higher than for HIV negative control patients, indicating mildly reduced VWFCP enzyme activity in HIV positive patients (regardless of the platelet count), in the absence of TTP. However, no significant difference in the cut-off value was noted between HIV positive patients with low platelet counts versus HIV positive patients with normal platelet counts (p=0.7783). The assay could therefore be used in HIV positive patients with TTP. VWFCP activity was assessed in twenty HIV positive patients with TTP. Two groups of HIV positive patients with TTP were identified based on VWFCP activity. Six patients (30%) had normal (one borderline) VWFCP activity (RCBA <51.51%), while the remaining 14 patients had severely reduced VWFCP levels (RCBA >90%). Of the patients with reduced VWFCP activity, only 5 patients had a detectable inhibitor, while an inhibitor was not detected in the remaining 8 patients. Conclusion: The rapid collagen binding ELISA assay is a cost effective semi-quantitative assay for the assessment of VWFCP activity. VWFCP activity in HIV positive patients appears to be slightly lower, however is not related to the platelet count. This suggests a slight baseline deficiency of VWFCP in the setting of HIV. The baseline VWFCP cut-off value in HIV allowed assessment of HIV positive patients with TTP. The results suggest heterogeneity of VWFCP activity in HIV-related TTP. A negative result (normal VWFCP activity) does not exclude TTP in patients with HIV-related TTP and other pathogenic factors may therefore be involved.
128

Barriers influencing the use of prevention of mother-to-child transmission of Human Immunodeficiency Virus follow-up services at Mankweng Clinics

Ramoshaba, Refilwe January 2017 (has links)
Thesis (M. A. (Sociology)) --University of Limpopo, 2017. / Refer to document
129

Dental Hygienists' Beliefs, Norms, Attitudes, and Intentions Toward Treating HIV/AIDS Patients

Clark-Alexander, Barbara 28 March 2008 (has links)
There is a great demand and need for oral health care during the course of HIV disease (HIV Costs and Services Utilization Study; Marcus et. al., 2005). HIV+ patients identified three key barriers to obtaining oral health treatment: 1) beliefs and attitudes of dental health care providers (DHCPs) may have lead to their unwillingness to treat HIV/AIDS patients; 2) the existence of racial and ethnic disparities in health care in the United States, and 3) how DHCPs perceive their risk of contracting HIV. The fear and stigma associated with treating patients with HIV further compromises their access to care and their health status. Oral health conditions associated with HIV disease are frequently more severe than those of the general population, making access to both dental and medical care imperative. Plus, Florida has some of the highest numbers of HIV/AIDS patients in the nation. This study was descriptive, cross-sectional and used quantitative methods to explore the dental hygienists' behavioral and normative beliefs, attitudes, and intentions toward treating patients with HIV/AIDS. A three-phase pilot study was conducted to assess the validity and reliability of the survey instrument. An email delivery method was used to implement the survey, and a 22% response rate was achieved (n=219). The majority of respondents were female (96%), white (89%), married (77%), currently working (86%), and had treated HIV/AIDS patients in private practice (80%). Bivariate analysis showed that dental hygienists' intentions toward treating HIV/AIDS patients were significantly associated with five independent variables, and binary logistic regression confirmed the significance of two of these associations. Overall, study participants indicated that they were willing to, and had positive attitudes toward, clinically treating HIV/AIDS patients; they were confident in their ability to treat them, and their normative beliefs did not hinder their intention to do so, and they did not worry about acquiring HIV in the workplace. Three recommendations were made: increase access to oral health care for HIV/AIDS patients within community settings by removing barriers to care, incorporate cultural/sensitivity training in all dental/dental hygiene school curriculums, and mandate Florida HIV/AIDS continuing education requirements every biennium for dentists and dental hygienists.
130

Peripheral neuropathy and quality of life of adults living with HIV/AIDS in Rulindo District in Rwanda.

Juvenal, Biraguma. January 2008 (has links)
<p>Peripheral neuropathy (PN) is a common neurological complication occurring in the asymptomatic and symptomatic stages of human immune deficiency virus (HIV) infection. The pain and other symptoms caused by PN can impair functional ability and limit physical activity that could affect quality of life (QoL). Additionally, studies done on quality of life of people living with HIV/AIDS have shown that, HIV-related neurological syndromes, including PN, significantly reduce QoL. The aim of this study was to determine the prevalence of peripheral neuropathy amongst and the quality of life of adults living with HIV/AIDS attending the out-patient clinic at Rutongo Hospital in Rulindo District in Rwanda.</p>

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