283 research outputs found

    Vaginal microbicides for preventing mother-to-child transmission of HIV infection - no evidence of an effect or evidence of no effect?

    Get PDF
    Background. Vaginal disinfection is a simple, potentially effective strategy for reducing mother-to-child transmission (MTCT) of HIV that can be implemented in combination with antiretroviraltherapy or even in the absence of prenatal HfV testing. We systematically reviewed currently available randomised controlled trials to estimate the benefits and risks of this intervention.Methods. We conducted an exhaustive search for published and. unpublished trials assessing the effect of vaginal microbicides on MTCT of HIV, extracted data in triplicate, assesed statistical heterogeneity between trial results, and conducted meta-analysis using Mantel-Haenszel's method.Findings. Five potentially eligible studies were iclentified, two of which met eligibility criteria. Pooling the data shows that the effect of vaginal disinfection on the risk of MTCT of HIV relative risk (RR) 0.94, 95% confidence interval (CI) 0.71 1.25) and neonatal death (RR 1.36, 95% CI 0.32- 5.79) is uncertain. The combined data (two trials with 708 participants) had less than 80% power to detect a 30% reduction in the risk of MTCT of HIV from a baseline risk of 30%, and are compatible with a widerange of effects; from a 29% reduction to a 25% increase in risk. One trial with 108 participants, showed no evidence that adverse effects increased inmothers (RR L02, 95% CI 0.87- 1.20) and found that adverse effects decreased in neonates (RR 0.45, 95% CI 0.32 - 0.64).Interpretation. At present there is insufficient and inconclusive evidence on the effect of vaginal microbicides on the risk of MTCT of HIV. This review identifies the need and provides the impetus for an adequately powered randomised controlled trial to assess the effect(s) of this inexpensive intervention

    Co-formulated abacavir-lamivudine-zidovudine for initial treatment of HIV infection and AIDS.

    Get PDF
    The primary objective of this review was to evaluate the antiviral efficacy of co-formulated abacavir-lamivudine-zidovudine for initial treatment of HIV infection. The secondary objectives were to evaluate the safety and tolerability of the triple drug combination. We identified 15 potentially eligible studies, four of which met our inclusion criteria. Our findings indicate that co-formulated abacavirlamivudine-zidovudine remains a viable option for initiating antiretroviral therapy, especially in HIV-infected patients with pre-existing hyperlipidaemia and those who do not tolerate ritonavir

    Molecular dissection of the myelin-associated glycoprotein receptor complex reveals cell type–specific mechanisms for neurite outgrowth inhibition

    Get PDF
    Neuronal Nogo66 receptor-1 (NgR1) binds the myelin inhibitors NogoA, OMgp, and myelin-associated glycoprotein (MAG) and has been proposed to function as the ligand-binding component of a receptor complex that also includes Lingo-1, p75NTR, or TROY. In this study, we use Vibrio cholerae neuraminidase (VCN) and mouse genetics to probe the molecular composition of the MAG receptor complex in postnatal retinal ganglion cells (RGCs). We find that VCN treatment is not sufficient to release MAG inhibition of RGCs; however, it does attenuate MAG inhibition of cerebellar granule neurons. Furthermore, the loss of p75NTR is not sufficient to release MAG inhibition of RGCs, but p75NTR−/− dorsal root ganglion neurons show enhanced growth on MAG compared to wild-type controls. Interestingly, TROY is not a functional substitute for p75NTR in RGCs. Finally, NgR1−/− RGCs are strongly inhibited by MAG. In the presence of VCN, however, NgR1−/− RGCs exhibit enhanced neurite growth. Collectively, our experiments reveal distinct and cell type–specific mechanisms for MAG-elicited growth inhibition

    Advances in childhood immunisation in South Africa: where to now? Programme managers’ views and evidence from systematic reviews.

    Get PDF
    Background: The Expanded Programme on Immunisation (EPI) is one of the most powerful and cost-effective public health programmes to improve child survival. We assessed challenges and enablers for the programme in South Africa, as we approach the 2015 deadline for the Millennium Development Goals. Methods: Between September 2009 and September 2010 we requested national and provincial EPI managers in South Africa to identify key challenges facing EPI, and to propose appropriate solutions. We collated their responses and searched for systematic reviews on the effectiveness of the proposed solutions; in the Health Systems Evidence, Cochrane Library, and PubMed electronic databases. We screened the search outputs, selected systematic reviews, extracted data, and assessed the quality of included reviews (using AMSTAR) and the quality of the evidence (using GRADE) in duplicate; resolving disagreements by discussion and consensus. Results: Challenges identified by EPI managers were linked to healthcare workers (insufficient knowledge of vaccines and immunisation), the public (anti-immunisation rumours and reluctance from parents), and health system (insufficient financial and human resources). Strategies proposed by managers to overcome the challenges include training, supervision, and audit and feedback; strengthening advocacy and social mobilisation; and sustainable EPI funding schemes, respectively. The findings from reliable systematic reviews indicate that interactive educational meetings, audit and feedback, and supportive supervision improve healthcare worker performance. Structured and interactive communication tools probably increase parents’ understanding of immunisation; and reminders and recall, use of community health workers, conditional cash transfers, and mass media interventions probably increase immunisation coverage. Finally, a national social health insurance scheme is a potential EPI financing mechanism; however, given the absence of high-quality evidence of effects, its implementation should be pilot-tested and the impacts and costs rigorously monitored. Conclusion: In line with the Millennium Development Goals, we have to ensure that our children’s right to health, development and survival is respected, protected and promoted. EPI is central to this vision. We found numerous promising strategies for improving EPI performance in South Africa. However, their implementation would need to be tailored to local circumstances and accompanied by high-quality monitoring and evaluation. The strength of our approach comes from having a strong framework for interventions before looking for systematic reviews. Without a framework, we would have been driven by what reviews have been done and what is easily researchable; rather than the values and preferences of key immunisation stakeholders

    Immunoproteasome Overexpression Underlies the Pathogenesis of Thyroid Oncocytes and Primary Hypothyroidism: Studies in Humans and Mice

    Get PDF
    BACKGROUND:Oncocytes of the thyroid gland (Hürthle cells) are found in tumors and autoimmune diseases. They have a unique appearance characterized by abundant granular eosinophilic cytoplasm and hyperchromatic nucleus. Their pathogenesis has remained, thus far, unknown. METHODOLOGY/PRINCIPAL FINDINGS:Using transgenic mice chronically expressing IFNgamma in thyroid gland, we showed changes in the thyroid follicular epithelium reminiscent of the human oncocyte. Transcriptome analysis comparing transgenic to wild type thyrocytes revealed increased levels of immunoproteasome subunits like LMP2 in transgenics, suggesting an important role of the immunoproteasome in oncocyte pathogenesis. Pharmacologic blockade of the proteasome, in fact, ameliorated the oncocytic phenotype. Genetic deletion of LMP2 subunit prevented the development of the oncocytic phenotype and primary hypothyroidism. LMP2 was also found expressed in oncocytes from patients with Hashimoto thyroiditis and Hürthle cell tumors. CONCLUSIONS/SIGNIFICANCE:In summary, we report that oncocytes are the result of an increased immunoproteasome expression secondary to a chronic inflammatory milieu, and suggest LMP2 as a novel therapeutic target for the treatment of oncocytic lesions and autoimmune hypothyroidism

    Early antituberculosis drug exposure in hospitalized patients with human immunodeficiency virus-associated tuberculosis

    Get PDF
    Aims: Patients hospitalized at the time of human immunodeficiency virus-associated tuberculosis (HIV-TB) diagnosis have high early mortality. We hypothesized that compared to outpatients, there would be lower anti-TB drug exposure in hospitalized HIV-TB patients, and amongst hospitalized patients exposure would be lower in patients who die or have high lactate (a sepsis marker). Methods: We performed pharmacokinetic sampling in hospitalized HIV-TB patients and outpatients. Plasma rifampicin, isoniazid and pyrazinamide concentrations were measured in samples collected predose and at 1, 2.5, 4, 6 and 8 hours on the third day of standard anti-TB therapy. Twelve-week mortality was ascertained for inpatients. Noncompartmental pharmacokinetic analysis was performed. Results: Pharmacokinetic data were collected in 59 hospitalized HIV-TB patients and 48 outpatients. Inpatient 12-week mortality was 11/59 (19%). Rifampicin, isoniazid and pyrazinamide exposure was similar between hospitalized and outpatients (maximum concentration [Cmax]: 7.4 vs 8.3 μg mL–1, P =.223; 3.6 vs 3.5 μg mL–1, P =.569; 50.1 vs 46.8 μg mL–1, P =.081; area under the concentration–time curve from 0 to 8 hours: 41.0 vs 43.8 mg h L–1, P = 0.290; 13.5 vs 12.4 mg h L–1, P =.630; 316.5 vs 292.2 mg h L–1, P =.164, respectively) and not lower in inpatients who died. Rifampicin and isoniazid Cmax were below recommended ranges in 61% and 39% of inpatients and 44% and 35% of outpatients. Rifampicin exposure was higher in patients with lactate >2.2 mmol L–1. Conclusion: Mortality in hospitalized HIV-TB patients was high. Early anti-TB drug exposure was similar to outpatients and not lower in inpatients who died. Rifampicin and isoniazid Cmax were suboptimal in 61% and 39% of inpatients and rifampicin exposure was higher in patients with high lactate. Treatment strategies need to be optimized to improve survival

    Clinical characteristics and initial management of patients with tuberculous pericarditis in the HIV era: the Investigation of the Management of Pericarditis in Africa (IMPI Africa) registry

    Get PDF
    BACKGROUND: The incidence of tuberculous pericarditis has increased in Africa as a result of the human immunodeficiency virus (HIV) epidemic. However, the effect of HIV co-infection on clinical features and prognosis in tuberculous pericarditis is not well characterised. We have used baseline data of the Investigation of the Management of Pericarditis in Africa (IMPI Africa) registry to assess the impact of HIV co-infection on clinical presentation, diagnostic evaluation, and treatment of patients with suspected tuberculous pericarditis in sub-Saharan Africa. METHODS: Consecutive adult patients in 15 hospitals in three countries in sub-Saharan Africa were recruited on commencement of treatment for tuberculous pericarditis, following informed consent. We recorded demographic, clinical, diagnostic and therapeutic information at baseline, and have used the chi-square test and analysis of variance to assess probabilities of significant differences (in these variables) between groups defined by HIV status. RESULTS: A total of 185 patients were enrolled from 01 March 2004 to 31 October 2004, 147 (79.5%) of whom had effusive, 28 (15.1%) effusive-constrictive, and 10 (5.4%) constrictive or acute dry pericarditis. Seventy-four (40%) had clinical features of HIV infection. Patients with clinical HIV disease were more likely to present with dyspnoea (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.4 to 7.4, P = 0.005) and electrocardiographic features of myopericarditis (OR 2.8, 95% CI 1.1 to 6.9, P = 0.03). In addition to electrocardiographic features of myopericarditis, a positive HIV serological status was associated with greater cardiomegaly (OR 3.89, 95% CI 1.34 to 11.32, P = 0.01) and haemodynamic instability (OR 9.68, 95% CI 2.09 to 44.80, P = 0.0008). However, stage of pericardial disease at diagnosis and use of diagnostic tests were not related to clinical HIV status. Similar results were obtained for serological HIV status. Most patients were treated on clinical grounds, with microbiological evidence of tuberculosis obtained in only 13 (7.0%) patients. Adjunctive corticosteroids were used in 109 (58.9%) patients, with patients having clinical HIV disease less likely to be put on them (OR 0.37, 95% CI 0.20 to 0.68). Seven patients were on antiretroviral drugs. CONCLUSION: Patients with suspected tuberculous pericarditis and HIV infection in Africa have greater evidence of myopericarditis, dyspnoea, and haemodynamic instability. These findings, if confirmed in other studies, may suggest more intensive management of the cardiac disease is warranted in patients with HIV-associated pericardial disease

    Genetic variation in TLR genes in Ugandan and South African populations and comparison with HapMap data

    Get PDF
    Genetic epidemiological studies of complex diseases often rely on data from the International HapMap Consortium for identification of single nucleotide polymorphisms (SNPs), particularly those that tag haplotypes. However, little is known about the relevance of the African populations used to collect HapMap data for study populations conducted elsewhere in Africa. Toll-like receptor (TLR) genes play a key role in susceptibility to various infectious diseases, including tuberculosis. We conducted full-exon sequencing in samples obtained from Uganda (n = 48) and South Africa (n = 48), in four genes in the TLR pathway: TLR2, TLR4, TLR6, and TIRAP. We identified one novel TIRAP SNP (with minor allele frequency [MAF] 3.2%) and a novel TLR6 SNP (MAF 8%) in the Ugandan population, and a TLR6 SNP that is unique to the South African population (MAF 14%). These SNPs were also not present in the 1000 Genomes data. Genotype and haplotype frequencies and linkage disequilibrium patterns in Uganda and South Africa were similar to African populations in the HapMap datasets. Multidimensional scaling analysis of polymorphisms in all four genes suggested broad overlap of all of the examined African populations. Based on these data, we propose that there is enough similarity among African populations represented in the HapMap database to justify initial SNP selection for genetic epidemiological studies in Uganda and South Africa. We also discovered three novel polymorphisms that appear to be population-specific and would only be detected by sequencing efforts

    Serial measurement of M. tuberculosis in blood from critically-ill patients with HIV-associated tuberculosis

    Get PDF
    BACKGROUND: Despite being highly prevalent in hospitalised patients with severe HIV-associated tuberculosis (TB) and sepsis, little is known about the mycobacteriology of Mycobacterium tuberculosis bloodstream infection (MTBBSI). We developed methods to serially measure bacillary load in blood and used these to characterise MTBBSI response to anti-TB therapy (ATT) and relationship with mortality. METHODS: We established a microscopy method for direct visualisation of M. tuberculosis bacilli in blood using a novel lysis-concentration protocol and the fluorescent probe, 4-N,N-dimethylaminonaphthalimide-trehalose (DMN-Tre). We tested blood using GeneXpert® MTB/RIF-Ultra (Xpert-ultra) and Myco/F lytic culture after processing blood through lysis-wash steps to remove PCR inhibitors and anti-microbial drug carry-over. HIV-positive patients predicted to have MTBBSI gave blood samples 0, 4, 24, 48 and 72 h after ATT initiation. Bacillary loads were quantified using microscopy, Xpert-ultra cycle threshold, and culture time-to-positivity. Pharmacodynamics were modelled using these measures combined on an ordinal scale, including association with 12-week mortality. FINDINGS: M. tuberculosis was detected in 27 of 28 recruited participants; 25 (89%) by blood Xpert-ultra, 22 (79%) by DMN-Tre microscopy, and 21 (75%) by Myco/F lytic blood culture. Eight (29%) participants died by 12-week follow-up. In a combined pharmacodynamic model, predicted probabilities of negative DMN-Tre microscopy, blood Xpert-ultra, or blood culture after 72 h treatment were 0·64, 0·27, and 0·94, respectively, in those who survived, compared with 0·23, 0·06, and 0·71 in those who died (posterior probability of slower clearance of MTBBSI in those that died >0·99). DMN-Tre microscopy of blood demonstrated heterogenous bacillary morphologies, including microcolonies and clumps. Bacillary cell-length varied significantly with ATT exposure (mean cell-length increase 0·13 log-µm/day; 95%CrI 0·10-0·16). INTERPRETATION: Pharmacodynamics of MTBBSI treatment can be captured using DMN-Tre microscopy, blood Xpert-ultra and culture. This could facilitate interventional trials in severe HIV-associated TB. FUNDING: Wellcome Trust, NIH Fogarty International Center, South African MRC, NIHR(UK), National Research Foundation of South Africa

    Contextualised strategies to increase childhood and adolescent vaccination coverage in South Africa : a mixed-methods study

    Get PDF
    CITATION: Wiysonge, Charles Shey et al. 2020. Contextualised strategies to increase childhood and adolescent vaccination coverage in South Africa : a mixed-methods study. BMJ Open, 10 (6):e028476, doi:10.1136/bmjopen-2018-028476.The original publication is available at: https://bmjopen.bmj.comIntroduction Despite the unparalleled success of immunisation in the control of vaccine preventable diseases, immunisation coverage in South Africa remains suboptimal. While many evidence-based interventions have successfully improved vaccination coverage in other countries, they are not necessarily appropriate to the immunisation needs, barriers and facilitators of South Africa. The aim of this research is to investigate barriers and facilitators to optimal vaccination uptake, and develop contextualised strategies and implementation plans to increase childhood and adolescent vaccination coverage in South Africa. Methods The study will employ a mixed-methods research design. It will be conducted over three iterative phases and use the Adopt, Contextualise or Adapt (ACA) model as an overarching conceptual framework. Phase 1 will identify, and develop a sampling frame of, immunisation stakeholders involved in the design, planning and implementation of childhood and human papillomavirus immunisation programmes in South Africa. Phase 2 will identify the main barriers and facilitators to, and solutions for, increasing vaccination coverage. This phase will comprise exploratory qualitative research with stakeholders and a review of existing systematic reviews on interventions for improving vaccination coverage. Using the findings from Phase 2 and the ACA model, Phase 3 will develop a set of proposed interventions and implementation action plans for improving immunisation coverage in South Africa. These plans will be discussed, revised and finalised through a series of participatory stakeholder workshops and an online questionnaire, conducted as part of Phase 3.Publisher's versio
    • …
    corecore