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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.
11

Evaluation of botanical extracts with immune enhancing and /or anti-HIV activity in vitro

Brink, Mnandi 10 November 2011 (has links)
M.Sc. / To successfully intervene in the HIV/AIDS pandemic, knowledge of the pathogenesis of the disease and factors that stimulate or inhibit viral replication are crucial. Plants are expected to produce antiviral compounds since viruses form one of the major groups of plant pathogens. The objective in this project was to investigate the effects of 6 plant extracts on immune responses as well as evaluate their potential anti-HIV activity. Plant species tested were: Hypoxis hemerocal/idea, Elephantorrhiza elephantina, Spirulina platensis, Echinacea purpurea, Echinacea pal/ida and Cannabis sativa. Extracts were prepared via 24 hour extraction or 12 hour reflux in H20, methanol and ethanol in a 1:5 ratio. The crude extracts were analysed by TLC and HPLC and shown to consist of complex related mixtures of compounds. Using LC-MS, partial identification of methanol extracts revealed the following expected compounds: 9- octadecenoic acid (E)- in Hypoxis hemerocallidea, 4H-1-benzopyran-4-one,2-(3,4- dihydroxyphenyl)-7 -(13-D-glucopyranosyloxy)-5-hydroxy- in E/ephantorrhiza e/ephantina, ethanol,2-butoxy-,phosphate in Spirulina platensis, 2-propenoic acid,3-(3,4-dihydroxyphenyl)- in Echinacea purpurea, 2-propenoic acid,3-(3,4-dihydroxyphenyl)- in Echinacea pal/ida and ~-9- tetrahydrocannabivarin in Cannabis sativa tincture. Viability assays using tetrazolium salts (XTT) gave a qualitative picture of events allowing us to assess host cell responses and extract toxicity. Extracts exhibited intrinsic absorbances at some visible wavelengths but did not interfere at the wavelengths used in this viability assay. Having analysed cell viability it was thought prudent to report on the type of cell death induced by either HIV or the extracts, so Annexin-V (indicator of apoptosis) and PI (indicator of necrosis) detected by flow cytometry was employed. Results obtained revealed that cells were driven towards necrosis rather than apoptosis. None of the extracts showed significant in vitro toxicity in CEMss, CEMNKR. U937, Jurkat and PM1 cells or ex vivo in PBMC at a concentration range of 1000f..lg/ml-4f.!g/ml. Viability assays were also an indirect indication of HIV's effect on the cells. As for the effect of extracts on the immune system, IL-2 secretion was stimulated by most of the extracts. The effect of plant extracts on HIV activity was also investigated by looking at core protein levels (p24 was generally decreased by methanol extracts), reverse transcriptase activity (no detectable influence) and envelope glycoprotein levels (gp120 levels were only marginally reduced). It appears that Echinacea purpurea, Echinacea pal/ida and Spirulina platensis have immune enhancing abilities, while Hypoxis hemerocallidea, Elephantorrhiza e/ephantina and Cannabis sativa have dual purposes by enhancing both immunity and inhibiting HIV activity.
12

An investigation of plant extracts with HIV reverse transcriptase inhibitory activity.

Basson, Adriaan Erasmus 06 May 2008 (has links)
The acquired immunodeficiency syndrome (AIDS) in humans, which is caused by the human immunodeficiency virus type 1 (HIV-1) remains among the leading causes of death worldwide. Although HAART has reduced HIV mortality significantly, adhering to the recommended drug schemes, significant toxicities experienced by treated patients, and the high mutation rate of the virus that seem to easily circumvent the action of these drugs emphasize the need for alternative treatment strategies. Medicinal plants are a good source for the discovery of novel antimicrobial chemotherapeutic agents. Reverse transcription is the most essential step for viral replication to succeed successfully. This makes reverse transcriptase the prime target for antiviral therapy against HIV. Emphasis was placed on the discovery of plants with inhibitory activity against HIV-1 reverse transcriptase. Crude extracts from the active plant(s) was screened in vitro for their ability to suppress HIV replication in suitable cell systems. The potential of isolating and identifying the active principle(s) was also investigated. Crude extracts from different parts of Gunnera perpensa showed similar amounts of inhibition: aqueous extracts (97% „b 0.110%SD), methanol/chloroform extracts (94% „b 2.374%SD), rhizome extracts (96% „b 0.475%SD), stem extracts (94% „b 3.723%SD), leaf extracts (96% „b 1.097% SD). Crude extracts were found to be significantly (P„T0.027) non-toxic to CEM.NKR.CCR5 cells and PBMCs at 5 ƒÝg/ml. In acutely infected CEM.NKR.CCR5 cells, acutely infected PBMCs, and chronically infected PBMCs Gunnera perpensa extracts did not significantly (P>0.05) increase cell viability or reduced HIV core protein content, over 4 days. The in vitro test did therefore not reflect the findings with the reverse transcriptase assay. Activity-guided fractionations of Gunnera perpensa rhizome extract lead to the collection of a significantly active fraction. NMR studies revealed the presence of an epimeric mixture of glucose ¡§contaminants¡¨ in this active fraction. The presence of these ¡§contaminants¡¨ concealed the true structure of the active principle. Gunnera perpensa was identified as containing a potential active principle that significantly inhibits recombinant HIV reverse transcriptase. Unfortunately, in vitro experiments could not confirm this finding. The identity and structure of the active principle remains unidentified. Future studies will be concerned with in vitro antiviral studies of the pure active principle. Furthermore, preliminary tests indicated that some of the original collection of crude extracts had anti-bacterial and anti-malarial activities. These findings can be investigated in future. / Dr. D. Meyer
13

The immunomodulatory properties of AZT used in the treatment of AIDS

McKallip, Robert James 10 June 2009 (has links)
AZT (3'-azido-2’, 3’-dideoxythymidine) has been shown to prolong the survival of patients infected with human immunodeficiency virus (HIV) and decrease the severity of opportunistic infections. Such studies have prompted the use of AZT to treat symptomless individuals infected with HIV in the hope of delaying or even preventing the progression to acquired immunodeficiency syndrome (AIDS). However, before chronic use of AZT in symptomless individuals is initiated, it is important to establish whether this anti-viral drug would directly alter the phenotype and functions of the cells involved in the immune system. In the current study, we observed that AZT when administered orally for 7 -14 days into DBA/2 mice at 500 - 1000 mg/kg body weight induced a dose-dependent decrease in cellularity of the thymus. AZT caused significant alterations in the thymus resulting from a significant decrease in the number of double-positive (CD4⁺CD8​​⁺) cells and an increase in the number of double-negative (CD4⁻CD8⁻) cells. Interestingly, after the i.p. administration of interleukin-2 (IL-2) simultaneously with AZT, the total cellularity of the thymus was completely reconstituted. We also observed that AZT effectively suppressed the in vivo T cell response to conaibumin and gp120 of HIV. Furthermore, the addition of AZT to in vitro cultures caused a dose-dependent decrease in T and B cell proliferative responses to mitogens at 50μM or greater concentrations. Also, AZT inhibited the generation of cytotoxic T lymphocytes when added to the culture and this inhibition was reconstituted by the addition of exogenous IL-2. Together, our studies demonstrate that AZT modulates the phenotype and function of cells of the immune system which, in turn, could have marked repercussions on immune responses of the host toward infections and cancers. Also, our data demonstrating that AZT can suppress T cell responsiveness against HIV antigens caution against chronic use of AZT in asymptomatic HIV-infected individuals. / Master of Science
14

Pharmacokinetic herb-drug interaction study of selected traditional medicines used as complementary and alternative medicine (CAM) for HIV/AIDS

Awortwe, Charles 03 1900 (has links)
Thesis (DMed)--Stellenbosch University, 2015 / ENGLISH ABSTRACT: Introduction The increasing intake of traditional medicines among HIV/AIDS patients in sub-Saharan Africa needs urgent consideration by clinicians and other healthcare providers since the safety of such medications are unknown. The pharmacokinetic parameters - Absorption, Distribution, Metabolism and Elimination (ADME) play important role in the safety evaluation of drugs, thus implicating drug metabolizing enzymes and transporters as critical indicators for herb-drug interactions. The objective of this study was to evaluate the risk potential of seven herbal medicines commonly consumed by HIV/AIDS patients for drug interactions applying in vitro models. In this study, inhibition and induction effects of the herbal medicines on cytochrome P450s (CYPs) 1A2, 2C9, 2C19, 2D6 and 3A4 as well as P-glycoprotein (P-gp) were investigated. Methods Herbal medicines – Lessertia frutescens, Hypoxis hemerocallidea, Kalanchoe integra and Taraxacum officinale were sourced from Medico Herbs, South Africa were identified by experts from Compton Herbarium, South African National Biodiversity Institute, Cape Town. Moringa oleifera, Echinacea purpurea and Kalanchoe crenata were obtained from the repository of the National Centre for Natural Product Research (NCNPR), University of Mississippi, USA. Reversible inhibitory effect of aqueous and methanol herbal extracts were evaluated in recombinant CYPs applying the fluorescent metabolites at specified excitation/emission wavelengths; CYP1A2 (3-cyano-7-hydroxycoumarin (CHC); 405/460 nm), CYP2C9, CYP2C19 and CYP3A4 (7-hydroxy-4-(trifluoromethyl)-coumarin (HFC); 405/535 nm) and CYP2D6 (7-hydroxy-4-(aminomethyl)-coumarin (HAMC); 390/460 nm). Comparative studies in human liver microsomes (HLM) and recombinant CYPs were conducted to investigate the inhibitory effect of methanol herbal extracts and fractions on 6β testosterone hydroxylation activity. Time dependent inhibitory (TDI) effect of the herbal extracts were evaluated applying the IC50 shift fold, normalized ratio and the NADPH-, time- and concentration-dependent approaches. Influence of herbal extracts on metabolic clearance of testosterone was assessed in both HLM and human hepatocytes. The effects of each herbal extract on expression of CYP1A2, CYP3A4 and MDR1 genes were evaluated in activated human pregnane X receptor (PXR) co-transfected HepG2 cells. Finally, the inhibitory effect of herbal extracts on P-gp was assessed using the calcein-acetoxymethyl ester (calcein-AM) uptake and the digoxin radiolabelled substrates in MDCKII-MDRI cells. Results The aqueous extracts of Moringa oleifera, Kalanchoe integra, Kalanchoe crenata, Echinacea purpurea and Lessertia frutescens demonstrated high risk of in vivo inhibition on CYPs 3A4 and 1A2 with Cmax/Ki >1.0. Methanol extracts of these herbal medicines also indicated potential risk of reversible drug interaction. The methanol extracts of M. oleifera, K. crenata and L. frutescens showed strong TDI effect on CYP3A4 with IC50 shift fold >1.5 and normalised ratio <0.7. Moringa oleifera intermediately reduced intrinsic clearance of testosterone in human hepatocytes (2 ≤ AUC ratio ≤ 5) when scaled up to humans. Methanol extracts of Echinacea purpurea up-regulated the expression of CYP1A2, CYP3A4 and MDR1 genes in activated PXR. Kalanchoe crenata and Echinacea purpurea indicated strong inhibition on P-gp by reducing transport of digoxin across hMDR1-MDCKII cell monolayer from basolateral to apical with IC50 values of 18.24 ± 2.52 μg/mL and 24.47 ± 4.97 μg/mL, respectively. Conclusion The herbal medicines especially M. oleifera, K. integra and E. purpurea have the potential to cause herb-drug interaction in vivo if sufficient hepatic concentration is achieved in humans. / AFRIKAANSE OPSOMMING: Inleiding Die verhoogde inname van tradisionele medisynes onder MIV/VIGS-pasiënte in sub-Sahara-Afrika verg dringend oorweging deur klinici en ander gesondheidsorgverskaffers, aangesien die veiligheid van sodanige medikasies onbekend is. Die farmakokinetiese parameters – Absorpsie, Distribusie, Metabolisme en Eliminasie (ADME) – speel ’n belangrike rol by die veiligheidsevaluering van geneesmiddels, en impliseer gevolglik geneesmiddel-metaboliserende ensieme en vervoerders as kritiese indikators vir krui-geneesmiddel-interaksies (HDI). Die oogmerk van hierdie studie is om die risikopotensiaal van sewe kruiemedisynes wat algemeen deur MIV/VIGS-pasiënte geneem word, vir geneesmiddel-interaksies te evalueer deur in vitro-modelle te gebruik. In hierdie studie is die inhiberings- en induseringsuitwerkings van die kruiemedisynes op sitochroom P450’s (verkort na CYP’s) 1A2, 2C9, 2C19, 2D6 en 3A4, sowel as P-glikoproteïen (P-gp), ondersoek. Metodes Kruiemedisynes – Lessertia frutescens, Hypoxis hemerocallidea, Kalanchoe integra en Taraxacum officinale – is van Medico Herbs, Suid-Afrika, bekom en deur kundiges van die Compton-herbarium, by die Suid-Afrikaanse Nasionale Biodiversiteitsinstituut, Kaapstad, geïdentifiseer. Moringa oleifera, Echinacea purpurea en Kalanchoe crenata is van die bewaarplek van die Nasionale Sentrum vir Natuurlike Produknavorsing (NCNPR) aan die Universiteit van Mississippi in die VSA verkry. Die omkeerbare inhiberende uitwerking van kruie-ekstrakte in water en metanol is in rekombinante CYP’s geëvalueer deur die gebruik van die fluoresserende metaboliete op gespesifiseerde opwekkings-/emissiegolflengtes; CYP1A2 (3-siaan-7-hidroksikumarien (CHC); 405/460 nm), CYP2C9, CYP2C19 en CYP3A4 (7-hidroksi-4-(trifluoormetiel)-kumarien (HFC); 405/535 nm) en CYP2D6 (7-hidroksi-4-(aminometiel)-kumarien (HAMC); 390/460 nm). Vergelykende studies van menslikelewermikrosome (HLM) en rekombinante CYP’s is uitgevoer om die inhiberende uitwerking van metanolkruie-ekstrakte en -fraksies op 6β-testosteroonhidroksileringsaktiwiteit te ondersoek. Die tydafhanklike inhiberende uitwerking (TDI) van die kruie-ekstrakte is geëvalueer deur gebruikmaking van die IC50-verskuiwingsvou-, die genormaliseerdeverhoudings- en die NADPH-, tyd- en konsentrasieafhanklike benaderings. Die invloed van kruie-ekstrakte op metaboliese testosteroonverheldering is in beide HLM en menslike hepatosiete geëvalueer. Die uitwerkings van elke kruie-ekstrak op die uitdrukking van CYP1A2-, CYP3A4- en MDR1-gene is in geaktiveerde menslike pregnaan-X-reseptor(PXR)-, ko-getransfekteerde HepG2-selle geëvalueer. Laastens is die inhiberende uitwerking van kruie-ekstrakte op P-gp geëvalueer, met gebruikmaking van die kalsien-asetoksimetiel-ester (kalsien-AM)-opname en die digoksien- radiogemerkte substrate in MDCKII-MDRI-selle. Resultate Die ekstrakte in water van M. oleifera, K. integra, K. crenata, E. purpurea en L. frutescens het ’n hoë risiko van in vivo-inhibering op CYP’s 3A4 en 1A2 met Cmaks/Ki >1.0 getoon. Ekstrakte van hierdie kruiemedisynes in metanol het verder potensiële risiko van omkeerbare geneesmiddelinteraksie getoon. Die ekstrakte van M. oleifera, K. crenata en L. frutescens in metanol het sterk TDI-uitwerking op CYP3A4 met IC50-verskuiwingsvou >1.5 en genormaliseerde verhouding <0.7 getoon. M. oleifera het intermediêre vermindering van intrinsieke testosteroonverheldering in menslike hepatosiete (2 ≤ AUC verhouding ≤ 5) tot gevolg wanneer die skaal na mense verhoog word. Ekstrakte van E. purpurea in metanol het die uitdrukking van CYP1A2-, CYP3A4- en MDR1-gene in geaktiveerde PXR opgereguleer. K. crenata en E. purpurea het sterk inhibering van P-gp getoon deur die vervoer van digoksien deur die hMDR1-MDCKII-selmonolaag van basolateraal tot apikaal met IC50-waardes van onderskeidelik 18.24 ± 2.52 μg/mL en 24.47 ± 4.97 μg/mL te verminder. Gevolgtrekking Kruiemedisynes, veral M. oleifera, K. integra en E. purpurea, het die potensiaal om HDI in vivo te veroorsaak indien voldoende hepatiese konsentrasie by mense bereik word.
15

Mathematical modelling of HIV/AIDS transmission under treatment structured by age of infection

Ejigu, Amsalework Ayele 03 1900 (has links)
Thesis (MSc (Mathematical Sciences))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: This thesis takes into account the different levels of infectiousness of the human immunodeficiency virus (HIV) infected individuals throughout their period of infection. Infectiousness depends on the time since infection. It is high shortly after the infection occurs and then much lower for several years, and thereafter a higher plateau is reached before the acquired immunodeficiency syndrome (AIDS) phase sets in. In line with this, we formulated a mathematical model which is structured according to the age of infection. To understand the dynamics of the disease, we first discuss and analyse a simple model in which the age of infection is not considered, but progression of the HIV-AIDS transmission is taken into consideration by introducing three stages of infection. Analysis of these models tells us that the disease can be eradicated from the population only if on average one infected individual infects less than one person in his or her infectious period, otherwise the disease persists. To investigate the reduction of the number of infections caused by a single infectious individual to less than one, we introduce different treatment strategies for a model which depends on the age of infection, and we analyse it numerically. Current strategies amount to introducing treatment only at a late stage of infection when the infected individual has already lived through most of the infectious period. From our numerical results, this strategy does not result in eradication of the disease, even though it does reduce the burden for the individual. To eradicate the disease from the population, everyone would need to be HIV tested regularly and undergo immediate treatment if found positive. / AFRIKAANSE OPSOMMING: Hierdie tesis hou rekening met die verskillende aansteeklikheidsvlakke van die menslike immuniteitsgebreksvirus (MIV) deur besmette individue gedurende hulle aansteeklikheidstydperk. Die graad van aansteeklikheid hang af van die tydperk sedert infeksie. Dit is hoog kort nadat die infeksie plaasvind en daarna heelwat laer vir etlike jare, en dan volg n hoer plato voordat uiteindelik die Verworwe-Immuniteitsgebreksindroom (VIGS) fase intree. In ooreenstemming hiermee, formuleer ons n wiskundige model van MIV-VIGSoordrag met n struktureer waarin die tydperk sedert infeksie bevat is. Om die dinamika van die siekte te verstaan, bespreek en analiseer ons eers n eenvoudige model sonder inagneming van die tydperk sedert infeksie, terwyl die progressie van MIV-VIGS-oordrag egter wel in ag geneem word deur die beskouing van drie stadiums van infeksie. Analise van die modelle wys dat die siekte in die bevolking slegs uitgeroei kan word as elke besmette mens gemiddeld minder as een ander individu aansteek gedurende die tydperk waarin hy of sy self besmet is, anders sal die siekte voortduur. Vir die ondersoek oor hoe om die aantal infeksies per besmette individu tot onder die waarde van een te verlaag, beskou ons verskeie behandelingsstrategiee binne die model, wat afhang van die tydperk sedert infeksie, en ondersoek hulle numeries. Die huidige behandelingstrategiee kom neer op behandeling slegs gedurende die laat sta- dium van infeksie, wanneer die besmette individu reeds die grootste deel van die aansteeklikheidsperiode deurleef het. Ons numeriese resultate toon dat hierdie strategie nie lei tot uitroeiing van die siekte nie, alhoewel dit wel die las van die siekte vir die individu verminder. Om die siekte binne die bevolking uit te roei, sou elkeen gereeld vir MIV getoets moes word en indien positief gevind, dadelik met behandeling moes begin.
16

Counterfeiting of HIV/AIDS medicines : implications for global epidemic : recommendations for workplace programs

Norris, Gerard Benedict 04 1900 (has links)
Thesis (MPhil)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: multiple therapeutic categories of medicines have been increasingly targeted for counterfeiting. According to Van Niekerk [Van Niekerk, Anton. (2001). Moral and social complexities of AIDS in Africa. University of Stellenbosch], “it is commonplace to identify and bewail a plethora of problems in the developing world generally, and in Africa in particular. Poverty, illiteracy, famine, political instability, natural disasters, and many more misfortunes dominate the history of this part of the world over the past 50 years. It was therefore adding uncalled (undeserved?) insult to already overwhelming injury when HIV/AIDS visibly struck the world since mid-1980. In spite of all the other calamities that Africa has to deal with, it nevertheless is no exaggeration to claim that HIV/AIDS nowadays constitutes the most serious health and social crisis and challenge that has ever befallen the continent”. Similar patterns involving HIV/AIDS are now emerging on other continents. One objective of this recent research study was to explore possible relationships between the growing scourges of the worldwide counterfeiting of medicines and parallels with the expanding global HIV/AIDS pandemic - as well as to examine potential relationships and risks associated with other diseases that have been observed to have ‘special associations’ with HIV and AIDS [e.g. sexually transmitted infections (STI’s), Tuberculosis (TB) and Malaria] - and possible impact on the “World of Work”. A second and important objective was to develop Recommendations for Workplace Programs. The information gathered has also been used to propose future studies regarding HIV/AIDS and counterfeiting. In the developing world, antibiotics and anti-parasitic medicines are included among the counterfeiters’ favorite targets. Strong parallels exist between locations where counterfeiting of medicines is taking place/product being distributed/sold and where HIV/AIDS is most prevalent and/or where the epidemic is expanding progressively. Counterfeiting of medicines used for treating HIV/AIDS raises the possibility of additional future complications developing in managing other global diseases such as Malaria and Tuberculosis, not to mention exacerbating the potential for developing resistance and encouraging mutation of the HI virus itself. It is also noteworthy that certain medical devices have also been found to be counterfeit. Global demographics and with particular reference to projected growth rates of populations of the developing world are of specific relevance to this subject of anticounterfeiting and medicines used for the treatment of HIV and AIDS. Indeed, next generations of humanity appear to be at unnecessary risk of being caught up in a confluence of forces whereby the practice of the counterfeiting of medicines could result in significant complications and unforeseen consequences regarding management of the global HIV/AIDS crisis. Following the research, recommendations for workplace programs were developed. The research study concludes with a comprehensive set of references. / AFRIKAANSE OPSOMMING: Die problamatiek aangaande die vervalsing (namaak) van medisyne word nou wereldwyd ervaar en het ‘n impak op beide die geindustrialiseerde en die ontwikkelende wereld. Menige medisyne in terapeutiese kategoriee is tot op hede as vervals geidentifeseer, met die direkte resultaat dat hulle ‘n minemale of geen terapeutiese uitwerking het nie. Wat nog erger is, is dat hierdie middels uiters gevaarlik is om te gebruik en selfs lewensgevaarlik kan wees. Dit is van groot betekenis dat ook medisyne wat bestem is om persone met HIV/VIGS te behandel, as vervals aangetoon is – en soedoende tot nog toe onbekende gevolge vir pasiente, die werkomgewing en ongekende risiko’s vir wereldwye gesondheidsorg en internasionale veiligheid en sekuriteit inhou. In hierdie studie word die onderwerp in taamlike besonderhede bestudeer en daar word afgesluit met aanbevelings oor programme in die werkplek wat ontwerp is om sorg en ondersteuning te bied aan werkers met HIV/VIGS. Verdere studie word ook aanbeveel om die tergende probleme wat volg op die vervalsing van medisyne in die behandling van persone met HIV/VIGS, en die implikasies hiervan, die hoof te bide.
17

A reinforcement learning design for HIV clinical trials

Parbhoo, Sonali 30 July 2014 (has links)
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2014. / Determining e ective treatment strategies for life-threatening illnesses such as HIV is a signi cant problem in clinical research. Currently, HIV treatment involves using combinations of anti-HIV drugs to inhibit the formation of drug-resistant strains. From a clinician's perspective, this usually requires careful selection of drugs on the basis of an individual's immune responses at a particular time. As the number of drugs available for treatment increases, this task becomes di cult. In a clinical trial setting, the task is even more challenging since experience using new drugs is limited. For these reasons, this research examines whether machine learning techniques, and more speci cally batch reinforcement learning, can be used for the purposes of determining the appropriate treatment for an HIV-infected patient at a particular time. To do so, we consider using tted Q-iteration with extremely randomized trees, neural tted Q-iteration and least squares policy iteration. The use of batch reinforcement learning means that samples of patient data are captured prior to learning to avoid imposing risks on a patient. Because samples are re-used, these methods are data-e cient and particularly suited to situations where large amounts of data are unavailable. We apply each of these learning methods to both numerically generated and real data sets. Results from this research highlight the advantages and disadvantages associated with each learning technique. Real data testing has revealed that these batch reinforcement learning techniques have the ability to suggest treatments that are reasonably consistent with those prescribed by clinicians. The inclusion of additional state variables describing more about an individual's health could further improve this learning process. Ultimately, the use of such reinforcement learning methods could be coupled with a clinician's knowledge for enhanced treatment design.
18

The ‘Lazarus experience’ : people with HIV making sense of their lives in the post-treatment era

Wong, Wai-Kwan Tim, University of Western Sydney, College of Arts, School of Psychology January 2007 (has links)
The medico-scientific advances made in the treatment of HIV and AIDS, which emerged in the mid 1990s, were significant. The Highly Active Anti-Retroviral Treatments (HAART) or anti- HIV treatments have been positioned as resources that changed the way HIV is now medically and socially constructed. Although HIV remains incurable, it is now constructed as a chronic disease that is treatable, manageable and people are no longer positioned as living with a ‘death sentence’. The research on which this thesis is based explores the subjective lived experiences of people with HIV living in urban Australia in the context of this change. The effects that the treatments have had on corporeality have also changed the ways people are now living with HIV in the post-treatment era. It is an era in which treatments for HIV are taken-for-granted, but issues, doubts and concerns relating to treatment use are firmly embedded in the everyday life of people with HIV. The findings suggest that whilst AIDS-related mortality has decreased since the availability of effective treatments, the notion of ‘quality of life’, as subjectively constituted and defined, is an ongoing negotiation that is predicated on people locating meaningfulness in their everyday lives. Despite the decreased threat of failing health and death, the findings also suggest that people are continuing to be confronted by, and therefore positioned as, having to make sense of complex issues embedded in living with a disease for which there is no cure. / Doctor of Philosophy (PhD)
19

The impact of lopinavir/ritonavir (Kaletra) on blood lipids in HIV/AIDS antivirus treated naïve patients in China

He, Xi, 何溪 January 2011 (has links)
published_or_final_version / Public Health / Master / Master of Public Health
20

Financial burden for HIV/AIDS patients to access antiretroviral therapy in Asian developing countries

Wong, Mei-wan, Farah, 黃美雲 January 2013 (has links)
Background: Since the beginning of 21st century, several Asian countries started implementing their national free antiretroviral therapy (ART) programs to tackle one of the most striking public health issues in Asia – HIV/AIDS. Despite the efforts being made, the treatment coverage remains as low as 44% in 2010. Previous studies have identified financial constraint is a major barrier in accessing ART and an important reason of poor ART adherence in Asia. The purpose of this literature review is to explore the extent of financial burden experienced by people living with HIV (PLHIV) where free ART policy is implemented, and to provide valuable information for policy-making in reducing financial barriers and improve uptake of ART. Methods: Literature search was performed by entering keywords in PubMed and Medline. Articles were screened and selected for in-depth review according to the inclusion and exclusion criteria. A process on data synthesis was performed on the final eligible papers. Results: Five studies from four Asian countries describing the out-of-pocket health expenditure incurred by PLHIV during the delivery of ART were included in this review. Findings: Out of all direct medical costs, the cost of drug was most important in contributing to the total costs for patients without health insurance, while the cost of transportation was more important for patients covered by health insurance. Direct medical costs increased with advancing stage of disease. Rural patients would have spent up to 1,173% of their monthly income per capita, or more than 100% of their total household expenditure even when ART was provided free-of-charge. Patients have also highlighted free ARV drugs were sometimes not available in the health facility and they had to turn to the private market. Hence, the extent of financial burden in this review might be underestimated. Conclusion: Based on the data available, we concluded that increased accessibility of free ART should be accompanied with sustained ARV drugs supply and increased financial support for PLHIV. / published_or_final_version / Community Medicine / Master / Master of Public Health

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