32 research outputs found
OASIS II
Information and communication technology for health (ICT4H) can provide solutions for health practices in low resource settings leading to improved health and health care. The presentation provides perspectives on health information systems that can be integrated into African healthcare systems. Possible designs and methods are surveyed in relation to the Open Architecture, Standards and Information Systems (OASIS) framework and with reference to examples such as the WHO electronic Recording and Reporting Portal
BioAfrica's HIV-1 Proteomics Resource: Combining protein data with bioinformatics tools
Most Internet online resources for investigating HIV biology contain either bioinformatics tools, protein information or sequence data. The objective of this study was to develop a comprehensive online proteomics resource that integrates bioinformatics with the latest information on HIV-1 protein structure, gene expression, post-transcriptional/post-translational modification, functional activity, and protein-macromolecule interactions. The BioAfrica HIV-1 Proteomics Resource is a website that contains detailed information about the HIV-1 proteome and protease cleavage sites, as well as data-mining tools that can be used to manipulate and query protein sequence data, a BLAST tool for initiating structural analyses of HIV-1 proteins, and a proteomics tools directory. The Proteome section contains extensive data on each of 19 HIV-1 proteins, including their functional properties, a sample analysis of HIV-1(HXB2), structural models and links to other online resources. The HIV-1 Protease Cleavage Sites section provides information on the position, subtype variation and genetic evolution of Gag, Gag-Pol and Nef cleavage sites. The HIV-1 Protein Data-mining Tool includes a set of 27 group M (subtypes A through K) reference sequences that can be used to assess the influence of genetic variation on immunological and functional domains of the protein. The BLAST Structure Tool identifies proteins with similar, experimentally determined topologies, and the Tools Directory provides a categorized list of websites and relevant software programs. This combined database and software repository is designed to facilitate the capture, retrieval and analysis of HIV-1 protein data, and to convert it into clinically useful information relating to the pathogenesis, transmission and therapeutic response of different HIV-1 variants. The HIV-1 Proteomics Resource is readily accessible through the BioAfrica website at
Modeling HIV-1 Drug Resistance as Episodic Directional Selection
The evolution of substitutions conferring drug resistance to HIV-1 is both episodic, occurring when patients are on antiretroviral therapy, and strongly directional, with site-specific resistant residues increasing in frequency over time. While methods exist to detect episodic diversifying selection and continuous directional selection, no evolutionary model combining these two properties has been proposed. We present two models of episodic directional selection (MEDS and EDEPS) which allow the a priori specification of lineages expected to have undergone directional selection. The models infer the sites and target residues that were likely subject to directional selection, using either codon or protein sequences. Compared to its null model of episodic diversifying selection, MEDS provides a superior fit to most sites known to be involved in drug resistance, and neither one test for episodic diversifying selection nor another for constant directional selection are able to detect as many true positives as MEDS and EDEPS while maintaining acceptable levels of false positives. This suggests that episodic directional selection is a better description of the process driving the evolution of drug resistance
Progression to AIDS in South Africa Is Associated with both Reverting and Compensatory Viral Mutations
We lack the understanding of why HIV-infected individuals in South Africa
progress to AIDS. We hypothesised that in end-stage disease there is a shifting
dynamic between T cell imposed immunity and viral immune escape, which, through
both compensatory and reverting viral mutations, results in increased viral
fitness, elevated plasma viral loads and disease progression. We explored how T
cell responses, viral adaptation and viral fitness inter-relate in South African
cohorts recruited from Bloemfontein, the Free State
(n = 278) and Durban, KwaZulu-Natal
(n = 775). Immune responses were measured by
γ-interferon ELISPOT assays. HLA-associated viral polymorphisms were
determined using phylogenetically corrected techniques, and viral replication
capacity (VRC) was measured by comparing the growth rate of gag-protease
recombinant viruses against recombinant NL4-3 viruses. We report that in
advanced disease (CD4 counts <100 cells/µl), T cell responses narrow,
with a relative decline in Gag-directed responses (p<0.0001). This is
associated with preserved selection pressure at specific viral amino acids
(e.g., the T242N polymorphism within the HLA-B*57/5801 restricted TW10
epitope), but with reversion at other sites (e.g., the T186S polymorphism within
the HLA-B*8101 restricted TL9 epitope), most notably in Gag and suggestive
of “immune relaxation”. The median VRC from patients with CD4 counts
<100 cells/µl was higher than from patients with CD4 counts ≥500
cells/µl (91.15% versus 85.19%,
p = 0.0004), potentially explaining the rise in viral load
associated with disease progression. Mutations at HIV Gag T186S and T242N
reduced VRC, however, in advanced disease only the T242N mutants demonstrated
increasing VRC, and were associated with compensatory mutations
(p = 0.013). These data provide novel insights into the
mechanisms of HIV disease progression in South Africa. Restoration of fitness
correlates with loss of viral control in late disease, with evidence for both
preserved and relaxed selection pressure across the HIV genome. Interventions
that maintain viral fitness costs could potentially slow progression
CD14+ macrophages that accumulate in the colon of African AIDS patients express pro-inflammatory cytokines and are responsive to lipopolysaccharide
BACKGROUND : Intestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play
a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of
these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and
increased microbial translocation (MT).
METHODS : Phenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS
patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory
bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections
(OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of
proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension
Array System. Statistical analyses were performed using Spearman’s correlation and Wilcoxon matched-pair tests.
Results between groups were analyzed using the Kruskal-Wallis with Dunn’s post-test and the Mann–Whitney U tests.
RESULTS : None of the study participants had evidence of enteric co-infections as assessed by stool analysis and
histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased
infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor
(TNF)-α, interleukin (IL)-1β, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C)
motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC
revealed significant co-localization of TNF-α and IL-1β with CD68+ cells. As in IBD, HIV was associated with a marked
increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide
(LPS). The frequency of CD14+ macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated
mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14+ cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS
CONCLUSIONS : Intestinal macrophages, in the absence of overt OIs, play an important role in driving persistentinflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatmentstrategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoringthe epithelial barrier and limiting MT in HIV-infected patients.This research and selected researchers (EC, TR, PM, SM and CS) were funded
in part by a grant from the Delegation of the European Union to South
Africa: “Drug Resistance Surveillance and Treatment Monitoring Network for
the Public Sector HIV Antiretroviral Treatment Programme in the Free State –
Sante 2007/147-790” and by a grant from the National Research Council of
South Africa, Unlocking the Future 61509.http://www.biomedcentral.com/bmcinfectdisam201
Final technical report : developer network and open source PDA software for health data; reporting period: 1 March 2006 - 28 February 2008
DraftThis project successfully developed an open source software application for mobile health data collection on handheld computers (personal digital assistants or PDAs), as well as simultaneously developing the OpenMRS Implementers Network. More effort and resources need to be invested in community-building activities in order to ensure that a particular project is adopted by the community, and so that open source projects are largely community-driven. Meaningful involvement with marginalized groups, including women, might be enhanced by twinning groups with project team members in an in-project mentoring relationship
HEAL: Establishing a Health Enterprise Architecture Lab in Africa
The presentation outlines a programme developed at the School of Computer Science, University of KwaZulu-Natal (UKZN) Westville Campus in South Africa, to establish a Centre of Excellence in Health Informatics. The long-term objective is a research network that works together to solve challenges in health informatics
Developing Open Architecture, Standards and Information Systems for healthcare in Africa (OASIS project)
The table of contents for this item can be shared with the requester. The requester may then choose one chapter, up to 10% of the item, as per the Fair Dealing provision of the Canadian Copyright ActThis research evaluates potential to build capacity and improve access to eHealth, while strengthening health information systems in Africa using open technologies. Partnerships have been developed between Open Architectures, Standards and Information Systems (OASIS) nodes, and the respective country Ministries of Health as well as local universities, NGOs, private and donor-funded health information system projects. Access to open source health software has been strengthened by providing training, workshops and an internship program. African capacity can be developed by means of community-driven open source projects and this should be considered when software choices are evaluated in a health setting