In May 1996 the AIDS Council of NSW launched Talk Test Test Trust ???Together (TTTT), an HIV prevention campaign aimed at decreasing risk of infection within gay men???s relationships. The rationale behind TTTT was ???negotiated safety???: that it was safe not to use condoms for anal sex in primary relationships if specific steps were followed. TTTT generated contestation within AIDS Councils in Australia and New Zealand, but also amongst researchers, policy makers and gay communities. Arguments about TTTT and negotiated safety appeared logical and reasonable and did not fall neatly along an Australia/New Zealand divide. This study used a qualitative approach to interview key HIV educators in New South Wales who were involved in the development of TTTT and New Zealand educators who did not promote negotiated safety. This thesis argues that in order to understand the contestation around negotiated safety and TTTT it is necessary to understand the broader social and historical factors that shape HIV prevention contexts and practice. These include factors arising from the epidemic itself (which, to some extent, were responsible for the difference between Australia and New Zealand) such as the increasing complexity of gay men???s risk reduction strategies, the rise of a positive voice, and impact of treatments and factors associated with and the broader context such as the rise and continuing history of a gay political and social movement and associated identity and community formation, and later, fragmentation, changing concepts of love, intimacy and relationships and of risk and the uncertainty, anxiety and fear from living in a complex individualised detraditionalised world. This approach will show that a focus on a dynamic epidemic, and the broader social and historical context can shed light on arguments made about negotiated safety and TTTT. Further, applying Bourdieu???s formulation of the complex interaction of habitus, fields and practice (1977) makes sense not only of the arguments made about negotiated safety and TTTT, but of educator practice and of HIV prevention, of the broader HIV and AIDS sector, and of how societies continue to learn to live with and adapt to the epidemic.

The spectrum of drugs used in HIV-infected patients has dramatically changed since triple antiretroviral combinations were introduced, albeit at the expense of some severe adverse events, in 1996. Long term complications of antiretroviral drug exposure, such as HIV lipodystrophy, as well as organ-specific disease of heart and bone are, therefore, a critical issue when designing antiretroviral regimens. Because it is difficult to predict the occurrence of lipodystrophy, and because there is no therapeutic agents able to combat lipodystrophy once established, avoidance of thymidine nucleoside analogues remains the most useful strategy to prevent and treat lipoatrophy; although this approach can worsen dyslipidaemia. Metabolic syndrome can and should be assessed as it predicts type 2 diabetes as well as cardiovascular events in HIV-infected individuals. Ongoing HIV replication is a risk factor for serious non-AIDS events including cardiovascular disease, as well as for AIDS. Therefore, HIV RNA suppression is imperative in all patients requiring antiretroviral therapy. Finally, HIV-infected adults on antiretroviral therapy, particularly in those receiving a boosted protease inhibitor, have a high prevalence of low bone mineral density. The estimation of fracture risk with the WHO FRAXTM tool deserves further validation in HIV-infected adults.

This thesis assesses factors associated with a number of short and long-term outcomes in HIV-infected patients receiving antiretroviral treatment in Asia. Analyses in this thesis were based on two cohorts of HIV-infected patients; The Treat Asia HIV Observational Database (TAHOD), a multi-centre prospective observational cohort from countries in Asia-Pacific region, and the HIV Netherlands Australia Thailand (HIV-NAT) collaboration cohort, a cohort of patients treated with antiretroviral treatments at HIV-NAT in Bangkok, Thailand. We examined factors associated with time to immunological failure endpoints, such as CD4≤ 200 cells/??L, CD4≤ 100 cells/ ??L, and CD4 return to baseline, and with the virological failure endpoint, detectable viral load defined as a value greater than 500 copies/mL. Multivariate Cox proportional hazard models were used. Results showed that CD4 count at baseline and changes in CD4 strongly predicted immunological failure. For virological failure, detectable viral load at baseline was the strongest predictor. As a step to developing simplified monitoring strategies, in which patients with a low risk of failure could have their monitoring CD4 count and viral load tests deferred, we developed predictive models for each immunological and virological failure endpoint. Models were developed on the HIV-NAT cohort, and validated on the independent TAHOD cohort. For predictive models, the complementary log-log transformation for each endpoint was fitted appropriate to the interval censored nature of the data. To assess goodness-of-fit, cut-offs were defined for the predicted risks that separated patients from low risk to high risk. Overall, the observed versus expected failures from HIV-NAT data agreed quite well across all endpoints, probably reflecting that the HIV-NAT database was the data we built the models upon. Not only did these models fit the HIV-NAT database well, they also discriminated patients from low to high risk groups. When we validated models with TAHOD data, the observed and expected failures agreed well only in the model for CD4 count return to baseline. For most of the endpoints, the predictive models overestimated the number of failures, with predicted values larger than observed. However, the proportions of failures were lowest in the low risk group and highest in the high risk group, indicating that our models did discriminate between patients at high and low risk, and that the predictive models might still be of use for the purpose of simplified monitoring strategies. With CD4 count and viral load monitoring tests now comprising a large component of the cost of HIV treatment in resource limited settings, we developed and assessed a simplified monitoring strategy that aimed to reduce the numbers of monitoring tests performed. The predictive models developed earlier were used to calculate the probabilities of failure in TAHOD patients. We assumed that patients would have their CD4 and viral load assessments annually, at baseline and at one year, predicted risk of failure at ensuing clinical visits, week 12, 24 and 36. For patients at low predicted risk of failure at ensuing clinical visits, we assessed the effect of deferring monitoring tests, both in terms of blood tests avoided, and in terms of delaying detection of failure in some patients. A number of levels for the predicted risk of failure that lead to deferral of testing were evaluated. The results suggested that predicted probabilities of failure of 10% - 20% gave the best results across all failure endpoints. These cut-offs could save a median of 598 (51.6%) (range 37 (2.6%)_-1,218 (81.9%) ) blood tests over the first year of treatment, but would fail to detect 29 (18%) (range 10 (7.4%) - 128 (39.3%) ) failures. The median time from failure to detection in those patients who did fail and had deferred monitoring tests was 28 weeks. Rates of antiretroviral treatment change in TAHOD were examined. We identified patterns and factors associated with the rate of treatment change. Median time to the first treatment change was 3.2 years. Factors predicting rate of treatment change in TAHOD were treatment combination, being on second or third combination, number of drugs available in each site and being an injecting drug user. The overall rate of treatment change in TAHOD was 29 per 1OO-person-year. Around 30% of patients stopped their treatment due to adverse events. These rates of treatment change are lower than have been seen in patients in western countries. This may be due to patients in developing countries having access to fewer antiretroviral drugs than patients in developed countries.

This thesis assesses factors associated with a number of short and long-term outcomes in HIV-infected patients receiving antiretroviral treatment in Asia. Analyses in this thesis were based on two cohorts of HIV-infected patients; The Treat Asia HIV Observational Database (TAHOD), a multi-centre prospective observational cohort from countries in Asia-Pacific region, and the HIV Netherlands Australia Thailand (HIV-NAT) collaboration cohort, a cohort of patients treated with antiretroviral treatments at HIV-NAT in Bangkok, Thailand. We examined factors associated with time to immunological failure endpoints, such as CD4≤ 200 cells/??L, CD4≤ 100 cells/ ??L, and CD4 return to baseline, and with the virological failure endpoint, detectable viral load defined as a value greater than 500 copies/mL. Multivariate Cox proportional hazard models were used. Results showed that CD4 count at baseline and changes in CD4 strongly predicted immunological failure. For virological failure, detectable viral load at baseline was the strongest predictor. As a step to developing simplified monitoring strategies, in which patients with a low risk of failure could have their monitoring CD4 count and viral load tests deferred, we developed predictive models for each immunological and virological failure endpoint. Models were developed on the HIV-NAT cohort, and validated on the independent TAHOD cohort. For predictive models, the complementary log-log transformation for each endpoint was fitted appropriate to the interval censored nature of the data. To assess goodness-of-fit, cut-offs were defined for the predicted risks that separated patients from low risk to high risk. Overall, the observed versus expected failures from HIV-NAT data agreed quite well across all endpoints, probably reflecting that the HIV-NAT database was the data we built the models upon. Not only did these models fit the HIV-NAT database well, they also discriminated patients from low to high risk groups. When we validated models with TAHOD data, the observed and expected failures agreed well only in the model for CD4 count return to baseline. For most of the endpoints, the predictive models overestimated the number of failures, with predicted values larger than observed. However, the proportions of failures were lowest in the low risk group and highest in the high risk group, indicating that our models did discriminate between patients at high and low risk, and that the predictive models might still be of use for the purpose of simplified monitoring strategies. With CD4 count and viral load monitoring tests now comprising a large component of the cost of HIV treatment in resource limited settings, we developed and assessed a simplified monitoring strategy that aimed to reduce the numbers of monitoring tests performed. The predictive models developed earlier were used to calculate the probabilities of failure in TAHOD patients. We assumed that patients would have their CD4 and viral load assessments annually, at baseline and at one year, predicted risk of failure at ensuing clinical visits, week 12, 24 and 36. For patients at low predicted risk of failure at ensuing clinical visits, we assessed the effect of deferring monitoring tests, both in terms of blood tests avoided, and in terms of delaying detection of failure in some patients. A number of levels for the predicted risk of failure that lead to deferral of testing were evaluated. The results suggested that predicted probabilities of failure of 10% - 20% gave the best results across all failure endpoints. These cut-offs could save a median of 598 (51.6%) (range 37 (2.6%)_-1,218 (81.9%) ) blood tests over the first year of treatment, but would fail to detect 29 (18%) (range 10 (7.4%) - 128 (39.3%) ) failures. The median time from failure to detection in those patients who did fail and had deferred monitoring tests was 28 weeks. Rates of antiretroviral treatment change in TAHOD were examined. We identified patterns and factors associated with the rate of treatment change. Median time to the first treatment change was 3.2 years. Factors predicting rate of treatment change in TAHOD were treatment combination, being on second or third combination, number of drugs available in each site and being an injecting drug user. The overall rate of treatment change in TAHOD was 29 per 1OO-person-year. Around 30% of patients stopped their treatment due to adverse events. These rates of treatment change are lower than have been seen in patients in western countries. This may be due to patients in developing countries having access to fewer antiretroviral drugs than patients in developed countries.

HIV infection and disease is a multistage process that involves a variety of cell types as the virus spreads through the body. Initially, dendritic cells (DCs) present at the mucosal site of infection bind and internalise HIV for degradation and presentation to T cells. As the DCs migrate to lymph nodes and mature, part of the internalised virions remains infective inside endosomal compartments. During formation of the immunological synapse between CD4 T cells and DCs, infective virions from dendritic cells are transferred to CD4 T cells leading to a strong infection of those cells allowing rapid virus dissemination throughout the body and establishment of the typical HIV infection. Various membrane receptors are involved in this process. Initial HIV binding to DCs is mediated by C-type lectin receptors such as the mannose receptor or DC-SIGN (DC specific intracellular adhesion molecule 3 grabbing non integrin) which is followed by virus internalisation and lysis albeit virus induced changes in endocytic routing prevents a proportion from degradation. Productive infection of DCs has also been observed allowing trans infection of CD4 T cells through a different mechanism. HIV infection of CD4 T cells, DCs and other cells is a multistep process initiated by binding of HIV envelope gp120 to the CD4 receptor, a 55 kDa transmembrane glycoprotein. Subsequent conformational changes in gp120 allow binding to a chemokine receptor, either CCR5 or CXCR4, followed by membrane fusion and infection. The aim of this thesis was to investigate protein associations with the HIV receptors DC-SIGN and CD4 in order to elucidate the mechanism of complex formation, virus entry and/or defining target sites for antiretroviral drugs. This thesis used a proteomic approach for studying the receptors with mass spectrometry-based protein identification as its core technology. A range of different approaches were developed and compared for identification of protein interactions and characterisation of the identified protein associations. An affinity purification of the CD4 receptor complex from lymphoid cells was used as the basis for detecting novel CD4-binding proteins. For this approach a strategy based on mass spectrometry identification of CD4 associating proteins using affinity chromatography and affinity-tag mediated purification of tryptic peptides was developed. This method proved successful for the identification of CD4 interacting proteins such as the strongly associated kinase p56lck, however a limited number of non-specifically bound proteins were also identified along the receptor complex. Using one-dimensional SDS-polyacrylamide gel electrophoresis followed by in-gel digests and mass spectrometry analysis, a large number of non-specifically binding proteins were identified along the CD4/lck complex. Evaluation of different lysis buffers in several independent experiments demonstrated that there was a large and inconsistent array of proteins that were obviously non-specifically bound to the receptor. No further specific binding partners were detected. These data suggested that protein interactions of CD4 on this cell type are of weak and/or transient nature. It also demonstrated a need for careful interpretation of proteomic data in the light of the propensity of non-specific binding under these conditions. To overcome dissociation of weak protein interactions, a method was developed using chemical cross-linking to preserve weak protein interactions on lymphoid cells. Affinity purification was used to purify CD4 along with cross-linked associated proteins and mass spectrometry analysis identified an interaction with the transferrin receptor CD71 and the tyrosine phosphatase CD45. The CD45-CD4 interaction is well known. The CD4-CD71 interaction was demonstrated to be a result from colocalization of the two molecules during formation of endocytic vesicles. Flow cytometry-based fluorescence resonance energy transfer (FRET) measurements were applied to confirm colocalization. A similar interaction was suspected for CD4 and DC-SIGN on the plasma membrane of DCs as cis infection of DCs has been demonstrated i.e. initial binding to DC-SIGN then to CD4/CCR5 on the same cell. Therefore, protein associations of DC-SIGN were investigated using the developed techniques. Using cross-linking, DC-SIGN was shown to assemble in large complexes on the surface of immature monocyte-derived DCs. Mass spectrometry analysis of the purified complexes identified them as homo-oligomers of DC-SIGN. The absence of CD4 suggested that the fraction interacting with CD4 at any one time must be small. The complexes of DC-SIGN were further characterised to be tetramers and successfully co-immunoprecipitated with HIV gp120 and mannan. DC-SIGN monomers were not evident demonstrating that the assembly of DC-SIGN into tetramers is required for high affinity binding of its natural and viral ligands. Thus potential antiviral agents aimed at blocking the early stage of HIV binding to DCs must simulate tetramers in order to neutralise the virus efficiently. Overall the thesis provides new information on protein interactions of CD4 and DC-SIGN, a careful investigation of "proteomics" techniques for identifying the proteins in affinity-purified samples and demonstrates the need for multifaceted analytical approaches to probe complex cellular systems.

Thesis (MScMed)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (PhD)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.

Thesis (M.S.) -- Central Connecticut State University, 2007. / Thesis advisor: Cynthia Pope. "... in partial fulfillment of the requirements for the degree of Master of Science in Geography." Includes bibliographical references (leaves 67-74). Also available via the World Wide Web.

Thesis (Ph.D.)--Tufts University, 2005. / Adviser: Davidson Hamer. Submitted to the School of Nutrition Science and Policy. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;