• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 194
  • 25
  • 14
  • 12
  • 11
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 345
  • 345
  • 345
  • 240
  • 107
  • 98
  • 94
  • 71
  • 63
  • 62
  • 59
  • 53
  • 50
  • 45
  • 41
  • 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.
311

Self-efficacy and beliefs about medications: implications for antiretroviral therapy adherence

Adefolalu, Adegoke Olusegun 27 September 2013 (has links)
The earlier optimism generated by the efficacy of antiretroviral drugs in human immuno-deficiency virus (HIV) patients has been dissipated in the face of the enormous chal-lenge of maintaining a nearly perfect adherence indefinitely. This study set to determine the influence of HIV adherence self-efficacy and beliefs about medicines on antiretrovi-ral therapy adherence, with the aim of developing a framework for enhancing antiretrovi-ral therapy (ART) adherence through focused intervention on modifiable factors from study variables that are strongly associated with ART adherence. A descriptive correlational design was used to assess the predictive relationships of HIV adherence Self-Efficacy, Beliefs about Medicines and ART adherence among 232 HIV-infected patients in a large public health facility in Pretoria. Participants' medication be-liefs were assessed using the Beliefs about Medicines Questionnaire, HIV adherence self-efficacy was assessed with HIV adherence self-efficacy scale (HIV-ASES) and ART adherence was assessed using the AIDS Clinical Trial Group questionnaire. Pearson correlation analysis was used to assess bivariate associations among the variables, and multiple regression analysis was used to examine the relationships among the inde-pendent variables and ART adherence. Mean adherence for the 232 participants was 95% (SD=13.2). Correlation analysis re-vealed positive bivariate associations between perceived general harm and overuse of medications, and ART adherence (p<0.05); between specific necessity and concerns about ARVs, and perceived general harm and overuse of medications (p<0.05); be-tween HIV adherence self efficacy and ART non-adherence (p<0.05). Multiple regres-sion analysis showed significance for perceived general harm and overuse of medica-tions on ART adherence (F(1;231)=11,583;p<0,001) with perceived general harmful ef-fects and overuse of medications explaining 4.8% of the variance. There was signifi-cance for HIV adherence self-efficacy on ART non-adherence (F(1;41)=4.440; p<0.041), with HIV-ASES explaining 9,8% of the variance. Based on the results, a framework for enhancing ART adherence was developed. Activities in the framework consist of baseline screening for adherence facilitators and barriers using the beliefs about medicine questionnaire and HIV ASES, this is followed by focused interventions on identified barriers of ART adherence / Health Studies / D.Litt. et Phil. (Health Studies)
312

Évaluation du besoin et de la pertinence de l'implantation d'un service d'injection supervisée en Montérégie

Milot, David-Martin 09 1900 (has links)
This research project aimed to conduct a strategic analysis of the implementation of a supervised injecting facility (SIF) in Montérégie. Using a mixed design, we first completed a portrait of the injection drug user (IDU) population. We then explored the perceptions of IDU and stakeholders with regard to the relevance of implementing a SIF in the region. Although some similarities were found with the IDU populations of Montreal and the province of Quebec, this population in Montérégie is characterized by a lower frequency of injections in public, less homeless people and lower rates of HIV and HCV infections. Despite these differences, the IDU population in Montérégie was found to have important physical and psychosocial needs. Although the relevance of a SIF in Montérégie is undeniable, improvements regarding the accessibility, continuity and appreciation of the actual services dedicated to IDU remain a priority. / Ce projet de recherche visait à réaliser une analyse stratégique de l’implantation d’un service d’injection supervisée (SIS) en Montérégie. Utilisant un devis mixte, son premier volet consistait à tracer un portrait de la population usagère de drogues par injection (UDI) montérégienne, alors que le second explorait les perceptions des UDI et des acteurs stratégiques œuvrant auprès d’eux quant à l’implantation d’un SIS dans la région. Bien que similaire aux populations UDI montréalaise et du Québec, celle de la Montérégie s’en distingue par le fait qu’elle s’injecte moins souvent dans des lieux publics, qu’elle soit sans domicile fixe à moindre proportion et par ses taux inférieurs d’infection au VIH et au VHC. Elle présente toutefois des besoins physiques et psychosociaux importants. Bien qu’un SIS soit jugé pertinent en Montérégie, une amélioration de l’accessibilité, de la continuité et de l’appréciation de l’offre de services actuelle dédiés aux UDI est considérée comme prioritaire.
313

Influence de l'initiation de la traduction sur le changement programmé du cadre de lecture en -1 responsable de la synthèse des enzymes du virus de l’immunodéficience humaine de type 1

Charbonneau, Johanie 05 1900 (has links)
Le virus de l’immunodéficience humaine de type 1 (VIH-1) est responsable du syndrome de l’immunodéficience acquise (SIDA). Il faut identifier de nouvelles cibles pour le développement d’agents anti-VIH-1, car ce virus développe une résistance aux agents présentement utilisés. Notre but est d’approfondir la caractérisation de l’étape du changement de cadre de lecture ribosomique en -1 (déphasage -1) nécessaire à la production du précurseur des enzymes du VIH-1. Ce déphasage est programmé et effectué par une minorité de ribosomes lorsqu’ils traduisent la séquence dite glissante à un endroit spécifique de l’ARN messager (ARNm) pleine-longueur du VIH-1. L’efficacité de déphasage est contrôlée par le signal stimulateur de déphasage (SSF), une tige-boucle irrégulière située en aval de la séquence glissante. La structure du SSF est déroulée lors du passage d’un ribosome, mais elle peut se reformer ensuite. Nous avons montré que des variations de l’initiation de la traduction affectent l’efficacité de déphasage. Nous avons utilisé, dans des cellules Jurkat-T et HEK 293T, un rapporteur bicistronique où les gènes codant pour les luciférases de la Renilla (Rluc) et de la luciole (Fluc) sont séparés par la région de déphasage du VIH-1. La Rluc est produite par tous les ribosomes traduisant l’ARNm rapporteur alors que la Fluc est produite uniquement par les ribosomes effectuant un déphasage. L’initiation de ce rapporteur est coiffe-dépendante, comme pour la majorité des ARNm cellulaires. Nous avons examiné l’effet de trois inhibiteurs de l’initiation et montré que leur présence augmente l’efficacité de déphasage. Nous avons ensuite étudié l’effet de la tige-boucle TAR, qui est présente à l’extrémité 5’ de tous les ARNm du VIH-1. TAR empêche la liaison de la petite sous-unité du ribosome (40S) à l’ARNm et module aussi l’activité de la protéine kinase dépendante de l’ARN double-brin (PKR). L’activation de PKR inhibe l’initiation en phosphorylant le facteur d’initiation eucaryote 2 (eIF2) alors que l’inhibition de PKR a l’effet inverse. Nous avons étudié l’effet de TAR sur la traduction et le déphasage via son effet sur PKR en utilisant TAR en trans ou en cis, mais à une certaine distance de l’extrémité 5’ afin d’éviter l’interférence avec la liaison de la 40S. Nous avons observé qu’une faible concentration de TAR, qui active PKR, augmente l’efficacité de déphasage alors qu’une concentration élevée de TAR, qui inhibe PKR, diminue cette efficacité. Nous avons proposé un modèle où des variations de l’initiation affectent l’efficacité de déphasage en modifiant la distance entre les ribosomes parcourant l’ARNm et, donc, la probabilité qu’ils rencontrent un SSF structuré. Par la suite, nous avons déterminé l’effet de la région 5’ non traduite (UTR) de l’ARNm pleine-longueur du VIH-1 sur l’efficacité de déphasage. Cette 5’UTR contient plusieurs régions structurées, dont TAR à l’extrémité 5’, qui peut interférer avec l’initiation. Cet ARNm a une coiffe permettant une initiation coiffe-dépendante ainsi qu’un site d’entrée interne des ribosomes (IRES), permettant une initiation IRES-dépendante. Nous avons introduit cette 5’UTR, complète ou en partie, comme 5’UTR de notre ARNm rapporteur bicistronique. Nos résultats démontrent que cette 5’UTR complète inhibe l’initiation coiffe dépendante et augmente l’efficacité de déphasage et que ces effets sont dus à la présence de TAR suivie de la tige-boucle Poly(A). Nous avons aussi construit un rapporteur tricistronique où les ribosomes exprimant les luciférases utilisent obligatoirement l’IRES. Nous avons observé que cette initiation par l’IRES est faible et que l’efficacité de déphasage correspondante est également faible. Nous avons formulé une hypothèse pour expliquer cette situation. Nous avons également observé que lorsque les deux modes d’initiation sont disponibles, l’initiation coiffe dépendante est prédominante. Finalement, nous avons étudié l’effet de la protéine virale Tat sur l’initiation de la traduction et sur l’efficacité de déphasage. Nous avons montré qu’elle augmente l’initiation de la traduction et que son effet est plus prononcé lorsque TAR est située à l’extrémité 5’ des ARNm. Nous proposons un modèle expliquant les effets de Tat sur l’initiation de la traduction par l’inhibition de PKR ainsi que par des changements de l’expression de protéines cellulaires déroulant TAR. Ces résultats permettent de mieux comprendre les mécanismes régissant le déphasage du VIH-1, ce qui est essentiel pour le développement d’agents anti-déphasage. / The human immunodeficiency virus type 1 (HIV-1) is responsible for the acquired immune deficiency syndrome (AIDS). HIV-1 develops a resistance towards the inhibitors used to treat infected patients. It is thus important to identify new targets for the development of novel antiretroviral agents. The aim of our work was to better characterize the programmed -1 ribosomal frameshift which generates the precursor of HIV-1 enzymes. The frameshift occurs at a specific sequence of HIV-1 full-length messenger RNA (mRNA), the slippery sequence, and is performed by a minority of the ribosomes translating this mRNA. The frameshift efficiency is controlled by the frameshift stimulatory signal (FSS), an irregular stem-loop located downstream of the slippery sequence. FSS structure is unfolded by every ribosome translating this region and can refold afterwards. We showed that HIV-1 frameshift efficiency is affected by changes in the rate of translation initiation. We transfected Jurkat-T and HEK 293T cells with a bicistronic reporter that contains the frameshift region of HIV-1 between the Renilla luciferase (Rluc) and the firefly luciferase (Fluc) genes. Rluc is produced by all ribosomes translating this reporter whereas only ribosomes that make a –1 frameshift produce Fluc. The translation of the reporter is initiated via a cap-dependant mode, like the majority of cellular mRNAs. We first determined the effect of three inhibitors of translation initiation. We showed that their presence increases the frameshift efficiency. We next determined the impact of the TAR stem loop, which is located at the 5’end of every HIV-1 mRNA. TAR is known to impair the binding of the small subunit of the ribosome (40S) to the mRNA. TAR also modulates the activity of the double-stranded RNA-dependent protein kinase (PKR). When PKR is activated, it phosphorylates the eukaryotic initiation factor 2 (eIF2), inhibiting translation initiation. The inhibition of PKR has the opposite effect. We studied the effect of TAR on PKR by positioning TAR at a distance of the 5’ end where it cannot interfere with the binding of the 40S. Our results showed that a small amount of TAR, which activates PKR, increases the frameshift efficiency whereas a large amount of TAR, which inhibits PKR, decreases it. A model is presented where the variations of translation initiation modulate HIV-1 frameshift efficiency by altering the distance between the elongating ribosomes. This influences the probability that these ribosomes encounter or not a folded FSS. We next observed the effect of the 5’ untranslated region (UTR) of HIV-1 full length mRNA on its frameshift efficiency. This 5’UTR contains several structured parts, including TAR at the 5’end, which can inhibit translation initiation. This mRNA has a cap and an internal ribosome entry site (IRES) and could then use a cap dependent and an IRES-dependent mode of translation initiation. We replaced the 5’UTR of our bicistronic reporter mRNA by the complete 5’UTR of HIV-1 full-length mRNA or a part of it. Our results showed that the presence of the complete 5’UTR inhibits cap-dependent initiation of translation and increases the frameshift efficiency. Those effects are mostly due to the presence of TAR followed by a Poly(A) stem-loop. We also constructed a tricistronic reporter where the ribosomes translating the luciferases have to use an IRES-dependent initiation mode. The rate of this initiation was low and the frameshift efficiency obtained was also low. We proposed a hypothesis accounting for this situation. We also observed that when both initiation modes are available, the cap-dependent mode seems to be highly favored. Finally, we studied the impact of the Tat viral protein on translation initiation and frameshift efficiency. We showed that the presence of Tat increases translation initiation and decreases the frameshift efficiency. Those effects are more important when TAR is present at the 5’end of mRNA. We propose a model explaining the effects of Tat on translation initiation by the inhibition of PKR and by changes in the expression of cellular proteins that are able to unfold TAR. Our results allow us to better understand the mechanisms controlling HIV-1 frameshift, which will help in the development of drugs targeting the HIV-1 frameshift.
314

Étude de la migration des populations de lymphocytes B du sang de patients infectés par le virus d’immunodéficience humaine (VIH)

Gauvin, Julie 11 1900 (has links)
La dérégulation du compartiment de cellules B est une conséquence importante de l’infection par le virus de l’immunodéficience humaine (VIH-1). On observe notamment une diminution des nombres de lymphocytes B sanguins ainsi qu’une variation des fréquences relatives des différentes populations de lymphocytes B chez les individus infectés par rapport aux contrôles sains. Notre laboratoire a précédemment démontré l’implication des cellules dendritiques dans la dérégulation des lymphocytes B via la roduction excessive de BLyS/BAFF, un stimulateur des cellules B. De plus, lors l’études menées chez la souris transgénique présentant une maladie semblable au SIDA, et chez la souris BLyS/BAFF transgénique, l’infection au VIH-1 fut associée à une expansion de la zone marginale (MZ) de la rate. De façon intéressante, nous observons chez les contrôleurs élites une diminution de la population B ‘mature’ de la MZ. Il s’agit du seul changement important chez les contrôleurs élites et reflète possiblement un recrutement de ces cellules vers la périphérie ainsi qu’une implication dans des mécanismes de contrôle de l’infection. Pour tenter d’expliquer et de mieux comprendre ces variations dans les fréquences des populations B, nous avons analysé les axes chimiotactiques CXCL13-CXCR5, CXCL12-CXCR4/CXCR7, CCL20-CCR6 et CCL25-CCR9. L’étude longitudinale de cohortes de patients avec différents types de progression clinique ou de contrôle de l’infection démontre une modulation des niveaux plasmatiques de la majorité des chimiokines analysées chez les progresseurs rapides et classiques. Au contraire, les contrôleurs élites conservent des niveaux normaux de chimiokines, démontrant leur capacité à maintenir l’homéostasie. La migration des populations de cellules B semble être modulée selon la progression ou le contrôle de l’infection. Les contrôleurs élites présentent une diminution de la population B ‘mature’ de la MZ et une augmentation de la fréquence d’expression du récepteur CXCR7 associé à la MZ chez la souris, suggérant un rôle important des cellules de la MZ dans le contrôle de l’infection au VIH-1. De façon générale, les résultats dans cette étude viennent enrichir nos connaissances du compartiment de cellules B dans le contexte de l’infection au VIH-1 et pourront contribuer à élaborer des stratégies préventives et thérapeutiques contre ce virus. / Deregulation of the B-cell compartment is an important consequence of human immunodeficiency virus (HIV-1) infection. We observe a decrease in blood B lymphocyte numbers accompanied by variations in the relative frequency of B cell populations in infected individuals when compared to healthy controls. Our lab has previously exposed the implication of dendritic cells in B-cell deregulation via excessive production of B lymphocyte stimulator (BLyS/BAFF). Additionally, the study of BLYS/BAFF-transgenic mice as well as mice exhibiting an AIDS-like disease revealed an expansion of the marginal zone (MZ) of the spleen. Interestingly, we found reduced relative frequencies of mature MZ-like B cells in the blood of elite controllers while rapid and classic HIV progressors had increased ‘precursor’ MZ-like cells. This variation in elite controllers is the only one observed for all population analyzed and could be the reflection of active recruitment of these cells to the periphery to help control infection. To try and understand these variations in B-cell frequencies we have analyzed the Btropic chemotaxis axes CXCL13-CXCR5, CXCL12-CXCR4/CXCR7, CCL20-CCR6 and CCL24-CCR9. The longitudinal study of patients with varying degrees of disease progression and control shows a modulation of the levels of most chemokines in the blood of rapid and classic progessors. Meanwhile, elite controllers maintain normal levels of these chemokines, demonstrating their ability to preserve homeostasis. Our results suggest that the type of disease progression impacts B-cell migration, resulting in modified B-cell population frequencies. The decrease in mature MZ-like B-cells and the increased frequency of cells expressing CXCR7, a receptor associated to the MZ in mice, in elite controllers suggest an important role for the MZ in controlling HIV-1 infection. Overall, our results provide more information about the B-cell compartment in the context of HIV-1 infection and can contribute to the elaboration of preventive and therapeutic strategies for HIV-1.
315

Pain management in people living with HIV in home based care

Moremi, Lillian Serah 09 1900 (has links)
The purpose of this study was to determine how pain in PLHIV on community home based care programme was managed using the Roy adaptation model (RAM) as the theoretical framework. This study used a descriptive mixed method research design which allowed for the research topic to be investigated and described in terms of both narrative qualitative accounts and descriptive statistics. A sequential exploratory approach was adopted in which qualitative data collection was conducted in the initial phase followed by quantitative data collection. Ten qualitative interviews, guided by the components of the RAM were conducted in the initial phase and a structured interview schedule (questionnaire) partially based on the result of the qualitative phase and (which was also structured in accordance with the RAM) was administered to 120 respondents who met the inclusion criteria of being on CHBC. Convenience sampling was used to select study participants and respondents in both phases of the study. Peripheral neuropathy was the most common pain syndrome experienced by patients. More females suffered numbness/tingling sensation of toes, followed by chest pains than their male counterparts. Pain experienced was moderate to severe which was not treated effectively. The study findings could assist health care providers, policy makers and researchers to invest into improving pain management for PLHIV, strengthen education of patients and their primary caregivers on the causes of pain and modalities to employ for pain relief and implement palliative care guidelines for PLHIV. / Health Studies / D. Litt. et Phil. (Health Studies)
316

Influence de l'initiation de la traduction sur le changement programmé du cadre de lecture en -1 responsable de la synthèse des enzymes du virus de l’immunodéficience humaine de type 1

Charbonneau, Johanie 05 1900 (has links)
Le virus de l’immunodéficience humaine de type 1 (VIH-1) est responsable du syndrome de l’immunodéficience acquise (SIDA). Il faut identifier de nouvelles cibles pour le développement d’agents anti-VIH-1, car ce virus développe une résistance aux agents présentement utilisés. Notre but est d’approfondir la caractérisation de l’étape du changement de cadre de lecture ribosomique en -1 (déphasage -1) nécessaire à la production du précurseur des enzymes du VIH-1. Ce déphasage est programmé et effectué par une minorité de ribosomes lorsqu’ils traduisent la séquence dite glissante à un endroit spécifique de l’ARN messager (ARNm) pleine-longueur du VIH-1. L’efficacité de déphasage est contrôlée par le signal stimulateur de déphasage (SSF), une tige-boucle irrégulière située en aval de la séquence glissante. La structure du SSF est déroulée lors du passage d’un ribosome, mais elle peut se reformer ensuite. Nous avons montré que des variations de l’initiation de la traduction affectent l’efficacité de déphasage. Nous avons utilisé, dans des cellules Jurkat-T et HEK 293T, un rapporteur bicistronique où les gènes codant pour les luciférases de la Renilla (Rluc) et de la luciole (Fluc) sont séparés par la région de déphasage du VIH-1. La Rluc est produite par tous les ribosomes traduisant l’ARNm rapporteur alors que la Fluc est produite uniquement par les ribosomes effectuant un déphasage. L’initiation de ce rapporteur est coiffe-dépendante, comme pour la majorité des ARNm cellulaires. Nous avons examiné l’effet de trois inhibiteurs de l’initiation et montré que leur présence augmente l’efficacité de déphasage. Nous avons ensuite étudié l’effet de la tige-boucle TAR, qui est présente à l’extrémité 5’ de tous les ARNm du VIH-1. TAR empêche la liaison de la petite sous-unité du ribosome (40S) à l’ARNm et module aussi l’activité de la protéine kinase dépendante de l’ARN double-brin (PKR). L’activation de PKR inhibe l’initiation en phosphorylant le facteur d’initiation eucaryote 2 (eIF2) alors que l’inhibition de PKR a l’effet inverse. Nous avons étudié l’effet de TAR sur la traduction et le déphasage via son effet sur PKR en utilisant TAR en trans ou en cis, mais à une certaine distance de l’extrémité 5’ afin d’éviter l’interférence avec la liaison de la 40S. Nous avons observé qu’une faible concentration de TAR, qui active PKR, augmente l’efficacité de déphasage alors qu’une concentration élevée de TAR, qui inhibe PKR, diminue cette efficacité. Nous avons proposé un modèle où des variations de l’initiation affectent l’efficacité de déphasage en modifiant la distance entre les ribosomes parcourant l’ARNm et, donc, la probabilité qu’ils rencontrent un SSF structuré. Par la suite, nous avons déterminé l’effet de la région 5’ non traduite (UTR) de l’ARNm pleine-longueur du VIH-1 sur l’efficacité de déphasage. Cette 5’UTR contient plusieurs régions structurées, dont TAR à l’extrémité 5’, qui peut interférer avec l’initiation. Cet ARNm a une coiffe permettant une initiation coiffe-dépendante ainsi qu’un site d’entrée interne des ribosomes (IRES), permettant une initiation IRES-dépendante. Nous avons introduit cette 5’UTR, complète ou en partie, comme 5’UTR de notre ARNm rapporteur bicistronique. Nos résultats démontrent que cette 5’UTR complète inhibe l’initiation coiffe dépendante et augmente l’efficacité de déphasage et que ces effets sont dus à la présence de TAR suivie de la tige-boucle Poly(A). Nous avons aussi construit un rapporteur tricistronique où les ribosomes exprimant les luciférases utilisent obligatoirement l’IRES. Nous avons observé que cette initiation par l’IRES est faible et que l’efficacité de déphasage correspondante est également faible. Nous avons formulé une hypothèse pour expliquer cette situation. Nous avons également observé que lorsque les deux modes d’initiation sont disponibles, l’initiation coiffe dépendante est prédominante. Finalement, nous avons étudié l’effet de la protéine virale Tat sur l’initiation de la traduction et sur l’efficacité de déphasage. Nous avons montré qu’elle augmente l’initiation de la traduction et que son effet est plus prononcé lorsque TAR est située à l’extrémité 5’ des ARNm. Nous proposons un modèle expliquant les effets de Tat sur l’initiation de la traduction par l’inhibition de PKR ainsi que par des changements de l’expression de protéines cellulaires déroulant TAR. Ces résultats permettent de mieux comprendre les mécanismes régissant le déphasage du VIH-1, ce qui est essentiel pour le développement d’agents anti-déphasage. / The human immunodeficiency virus type 1 (HIV-1) is responsible for the acquired immune deficiency syndrome (AIDS). HIV-1 develops a resistance towards the inhibitors used to treat infected patients. It is thus important to identify new targets for the development of novel antiretroviral agents. The aim of our work was to better characterize the programmed -1 ribosomal frameshift which generates the precursor of HIV-1 enzymes. The frameshift occurs at a specific sequence of HIV-1 full-length messenger RNA (mRNA), the slippery sequence, and is performed by a minority of the ribosomes translating this mRNA. The frameshift efficiency is controlled by the frameshift stimulatory signal (FSS), an irregular stem-loop located downstream of the slippery sequence. FSS structure is unfolded by every ribosome translating this region and can refold afterwards. We showed that HIV-1 frameshift efficiency is affected by changes in the rate of translation initiation. We transfected Jurkat-T and HEK 293T cells with a bicistronic reporter that contains the frameshift region of HIV-1 between the Renilla luciferase (Rluc) and the firefly luciferase (Fluc) genes. Rluc is produced by all ribosomes translating this reporter whereas only ribosomes that make a –1 frameshift produce Fluc. The translation of the reporter is initiated via a cap-dependant mode, like the majority of cellular mRNAs. We first determined the effect of three inhibitors of translation initiation. We showed that their presence increases the frameshift efficiency. We next determined the impact of the TAR stem loop, which is located at the 5’end of every HIV-1 mRNA. TAR is known to impair the binding of the small subunit of the ribosome (40S) to the mRNA. TAR also modulates the activity of the double-stranded RNA-dependent protein kinase (PKR). When PKR is activated, it phosphorylates the eukaryotic initiation factor 2 (eIF2), inhibiting translation initiation. The inhibition of PKR has the opposite effect. We studied the effect of TAR on PKR by positioning TAR at a distance of the 5’ end where it cannot interfere with the binding of the 40S. Our results showed that a small amount of TAR, which activates PKR, increases the frameshift efficiency whereas a large amount of TAR, which inhibits PKR, decreases it. A model is presented where the variations of translation initiation modulate HIV-1 frameshift efficiency by altering the distance between the elongating ribosomes. This influences the probability that these ribosomes encounter or not a folded FSS. We next observed the effect of the 5’ untranslated region (UTR) of HIV-1 full length mRNA on its frameshift efficiency. This 5’UTR contains several structured parts, including TAR at the 5’end, which can inhibit translation initiation. This mRNA has a cap and an internal ribosome entry site (IRES) and could then use a cap dependent and an IRES-dependent mode of translation initiation. We replaced the 5’UTR of our bicistronic reporter mRNA by the complete 5’UTR of HIV-1 full-length mRNA or a part of it. Our results showed that the presence of the complete 5’UTR inhibits cap-dependent initiation of translation and increases the frameshift efficiency. Those effects are mostly due to the presence of TAR followed by a Poly(A) stem-loop. We also constructed a tricistronic reporter where the ribosomes translating the luciferases have to use an IRES-dependent initiation mode. The rate of this initiation was low and the frameshift efficiency obtained was also low. We proposed a hypothesis accounting for this situation. We also observed that when both initiation modes are available, the cap-dependent mode seems to be highly favored. Finally, we studied the impact of the Tat viral protein on translation initiation and frameshift efficiency. We showed that the presence of Tat increases translation initiation and decreases the frameshift efficiency. Those effects are more important when TAR is present at the 5’end of mRNA. We propose a model explaining the effects of Tat on translation initiation by the inhibition of PKR and by changes in the expression of cellular proteins that are able to unfold TAR. Our results allow us to better understand the mechanisms controlling HIV-1 frameshift, which will help in the development of drugs targeting the HIV-1 frameshift.
317

Perceptions of human immunodeficiency virus positive pregnant mothers regarding the prevention of mother-to-child transmission, option B+ Programme in a public health unit in Manzini

Mbatha, Trusty Lomcebo 11 1900 (has links)
Text in English / The purpose of the study was to explore and describe the perceptions of the HIV positive pregnant mothers regarding the PMTCT Option B+ programme in order to identify and describe gaps; and also help the Swaziland government address these gaps. The study was conducted in one of the public health units in the Manzini Region of Swaziland. The qualitative, exploratory and descriptive research design was used and data collection was done using individual interviews and field notes. Permission was also requested from the participants in order to record the interviews. Population of the study were all cases of HIV positive pregnant mothers enrolled on PMTCT Option B+ programme, and were aged between 18 and 40 years. Number of participants sampled was 20 and only 17 participants were interviewed. Themes of the study were: perceptions of being enrolled on the PMTCT Option B+ programme, understanding about PMTCT Option B+ programme and information needed with regard to PMTCT Option B+ programme, perceptions with the care received from the nurses and their assistance on PMTCT Option B+ programme, effectiveness of the PMTCT Option B+ programme and challenges of taking ARVs. The findings revealed that Option B+ programme was perceived as preventing HIV from mother-to-child. It boosts the mother’s immune system, prevents opportunistic infections and prolongs life. Knowledge and understanding of the programme was displayed by the participants even though challenges such as discrimination and no support by families and partners were mentioned. Improvement of the programme on how to prevent the spread of HIV to babies and strategies to assist participants on how to disclose were recommended. This was found to be having a huge effect on treatment adherence. / Health Studies / M.A. (Health Studies)
318

The effect of a provincial communcation strategy to address HIV, AIDS, STIs and TB (HAST) in the Limpopo Province

Rapakwana, Ngwako Johannah 02 1900 (has links)
The lack of a contextualised, relevant communication strategy focusing specifically on HAST diseases in the Limpopo Province was the impetus for this research. The purpose of this study was, therefore, to explore the knowledge, perceptions and utilisation of health facilities for HAST in order to develop an acceptable and effective communication strategy for the Province to address the high rate of HAST diseases. The study followed a qualitative approach guided by the major tenets of the Health Belief Model, namely, to determine modifying factors, individual beliefs and cues for action. An in-depth literature review was followed by focus group interviews with the community members and personal interviews with District and Provincial Deputy Directors. Based on these findings, a communication strategy was drafted and piloted for three months in one of the districts in Limpopo. Further refinement of the communication strategy followed after member-checking and further interviews with directors HAST. The final strategy specifically focused on risk groups with each of the diseases in terms of their beliefs and perceptions. It further resulted in guidelines for health providers in terms of the content and implementation of effective communication strategies within the context of educational, cultural, social and economic factors relevant to Limpopo / Health Studies / D. Litt. et Phil. (Health Studies)
319

The effects of an electronic medical record on patient management in selected Human Immunodefiency Virus clinics in Johannesburg

Mashamaite, Sello Sophonia 11 1900 (has links)
The purpose of the study was to describe the effects of an EMR on patient management in selected HIV clinics in Johannesburg. A quantitative, descriptive, cross-sectional study was undertaken in four HIV clinics in Johannesburg. The subjects (N=44) were the healthcare workers selected by stratified random sampling. Consent was requested from each subject and from the clinics in Johannesburg. Data was collected using structured questionnaires. Median age of subjects was 36, 82% were female. 86% had tertiary qualifications. 55% were clinicians. 52% had 2-3 years work experience. 80% had computer experience, 86% had over one year EMR experience. 90% used the EMR daily, 93% preferred EMR to paper. 93% had EMR training, 17% used EMR to capture clinical data. 87% perceived EMR to have more benefits; most felt doctor-patient relationship was not interfered with. 89% were satisfied with the EMR’s overall performance. The effects of EMR benefit HIV patient management. / Health Studies / MA (Public Health)
320

Self-efficacy and beliefs about medications: implications for antiretroviral therapy adherence

Adefolalu, Adegoke Olusegun 27 September 2013 (has links)
The earlier optimism generated by the efficacy of antiretroviral drugs in human immuno-deficiency virus (HIV) patients has been dissipated in the face of the enormous chal-lenge of maintaining a nearly perfect adherence indefinitely. This study set to determine the influence of HIV adherence self-efficacy and beliefs about medicines on antiretrovi-ral therapy adherence, with the aim of developing a framework for enhancing antiretrovi-ral therapy (ART) adherence through focused intervention on modifiable factors from study variables that are strongly associated with ART adherence. A descriptive correlational design was used to assess the predictive relationships of HIV adherence Self-Efficacy, Beliefs about Medicines and ART adherence among 232 HIV-infected patients in a large public health facility in Pretoria. Participants' medication be-liefs were assessed using the Beliefs about Medicines Questionnaire, HIV adherence self-efficacy was assessed with HIV adherence self-efficacy scale (HIV-ASES) and ART adherence was assessed using the AIDS Clinical Trial Group questionnaire. Pearson correlation analysis was used to assess bivariate associations among the variables, and multiple regression analysis was used to examine the relationships among the inde-pendent variables and ART adherence. Mean adherence for the 232 participants was 95% (SD=13.2). Correlation analysis re-vealed positive bivariate associations between perceived general harm and overuse of medications, and ART adherence (p<0.05); between specific necessity and concerns about ARVs, and perceived general harm and overuse of medications (p<0.05); be-tween HIV adherence self efficacy and ART non-adherence (p<0.05). Multiple regres-sion analysis showed significance for perceived general harm and overuse of medica-tions on ART adherence (F(1;231)=11,583;p<0,001) with perceived general harmful ef-fects and overuse of medications explaining 4.8% of the variance. There was signifi-cance for HIV adherence self-efficacy on ART non-adherence (F(1;41)=4.440; p<0.041), with HIV-ASES explaining 9,8% of the variance. Based on the results, a framework for enhancing ART adherence was developed. Activities in the framework consist of baseline screening for adherence facilitators and barriers using the beliefs about medicine questionnaire and HIV ASES, this is followed by focused interventions on identified barriers of ART adherence / Health Studies / D.Litt. et Phil. (Health Studies)

Page generated in 0.2888 seconds