29 research outputs found
A qualitative evaluation of volunteers' experiences in a phase I/II HIV vaccine trial in Tanzania
Evaluating experiences of volunteers in an HIV vaccine trial will be useful for the conduct of future trials. The purpose of this study among volunteers who participated in a phase I/II HIV vaccine trial in Dar es Salaam, Tanzania was to assess what characterized their experiences during the trial. We conducted four focus group discussions with 35 out of the 60 individuals (women and men) after the five scheduled vaccinations. An interpretive description approach was applied to data analysis. As a result of the trial interventions, both men and women gained confidence in their own abilities to have safer, less risky sexual behaviour. The participants experienced the trial as a way of accessing free [insured] medical services. Most of the men said they had gone from self-medication to professional medical consultation. Despite these benefits, the participants faced various challenges during the trial. Such challenges included mistrust of the trial shown by health care providers who were not connected to the trial and discouragement from friends, colleagues and family members who questioned the safety of the trial. However, they managed to cope with these doubts by using both personal and trial related interventions. We found that during the phase I/II HIV vaccine trial, participants had both the opportunities and the ability to cope with the doubts from the surrounding community. Follow up visits enhanced the opportunities and individuals' abilities to cope with the doubts during the trial. Understanding this discourse may be useful for the trial implementers when designing future trials.\ud
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In vitro reactivation of latent HIV-1 by cytostatic bis (thiosemicarbazonate) gold(III) complexes
BACKGROUND : A number of cytostatic agents have been investigated for the ability to reactivate latent viral
reservoirs, which is a major prerequisite for the eradication of HIV-1 infection. Two cytostatic bis(thiosemicarbazonate)
gold(III) complexes (designated 1 and 2) were tested for this potential in the U1 latency model of HIV-1 infection.
METHODS : Cell viability in the presence or absence of 1 and 2 was determined using a tetrazolium dye and evidence of
reactivation was assessed by p24 antigen capture following exposure to a latency stimulant, phorbol myristate acetate
(PMA) and or test compounds. The latency reactivation mechanism was explored by determining the effect of the
complexes on protein kinase C (PKC), histone deacetylases (HDAC) and proinflammatory cytokine production.
RESULTS : The CC50 of the complexes in U1 cells were 0.53 ± 0.12 μM for 1 and 1.0 ± 0.4 μM for 2. In the absence of PMA
and at non toxic concentrations of 0.2 and 0.5 μM, 1 and 2 significantly (p ≤ 0.02) reactivated virus in U1 cells by 2.7
and 2.3 fold respectively. In comparison, a 2.6 fold increase (p = 0.03) in viral reactivation was observed for hydroxyurea
(HU), which was used as a cytostatic and latent HIV reactivation control. Viral reactivation was absent for the complexes
during co-stimulation with PMA indicating the lack of an additive effect between the chemicals as well as an absence
of inhibition of PMA induced HIV reactivation but for HU inhibition of the stimulant’s activity was observed (p = 0.01).
Complex 1 and 2 activated PKC activity by up to 32% (p < 0.05) but no significant inhibition of HDAC was observed.
Increases in TNF-α levels suggested that the reactivation of virus by the complexes may have been due to contributions
from the latter and the activation of PKC.
CONCLUSION : The ethyl group structural difference between 1 and 2 seems to influence bioactivity with lower active
concentrations of 1, suggesting that further structural modifications should improve specificity. The cytostatic effect of 1
and 2 and now HIV reactivation from a U1 latency model is consistent with that of the cytostatic agent, HU. These
findings suggest that the complexes have a potential dual (cytostatic and reactivation) role in viral “activation/elimination”.AuTEK Biomed (Mintek and Harmony Gold),Technology Innovation Agency (TIA) and the University of Pretoria.http://www.biomedcentral.com/bmcinfectdis/hb201
Corrigendum to: “Measurement of the tt ̄ production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector” [Phys. Lett. B 761 (2016) 136–157]
This paper describes a measurement of the inclusive top quark pair production cross-section (sigma(t (t) over bar)) with a data sample of 3.2fb(-1)of proton-proton collisions at a centre-of-mass energy of root s= 13TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron-muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously sigma(t (t) over bar) and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be:sigma(t (t) over bar) = 818 +/- 8 (stat) +/- 27 (syst) +/- 19 (lumi) +/- 12 (beam) pb,where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented
Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton–proton collision data
Many of the interesting physics processes to be measured at the LHC have a signature involving one or more isolated electrons. The electron reconstruction and identification efficiencies of the ATLAS detector at the LHC have been evaluated using proton–proton collision data collected in 2011 at s√=7 TeV and corresponding to an integrated luminosity of 4.7 fb −1. Tag-and-probe methods using events with leptonic decays of W and Z bosons and J/ψ mesons are employed to benchmark these performance parameters. The combination of all measurements results in identification efficiencies determined with an accuracy at the few per mil level for electron transverse energy greater than 30 GeV
Efficacy and safety of a once-daily single-tablet regimen of tenofovir, lamivudine, and efavirenz assessed at 144 weeks among antiretroviral-naive and experienced HIV-1-infected Thai adults
OBJECTIVE: To assess the efficacy and safety of a new single-tablet regimen (STR) of tenofovir disoproxil fumarate (TDF) 300mg, lamivudine (3TC) 300mg, and efavirenz (EFV) 600mg in HIV-infected Thai patients. METHODS: This was a prospective study performed for 144 weeks among 51 treatment-naive patients and 49 experienced patients on separate tablets of TDF, 3TC, and EFV with HIV RNA<50 copies/ml. CD4, HIV RNA, liver and renal function, and lipid profiles were assessed at baseline, weeks 12, 24, and 48, and then every 24 weeks. RESULTS: The median baseline CD4 cell count was 512 cells/mul for treatment-experienced patients and 230 cells/mul for treatment-naive patients. Median baseline log10 HIV-1 RNA for treatment-naive subjects was 4.9 copies/ml. From the intention-to-treat (ITT) analysis, the proportion of subjects with HIV RNA <50 copies/ml at week 48, 96, and 144 was 95%, 94%, and 94%, respectively, for antiretroviral-experienced patients and 88%, 90%, and 80%, respectively, for antiretroviral-naive patients. One virological failure at week 12 had primary drug resistance of K70R, T69D, V75L. Three serious adverse events occurred (tension headache, infective endocarditis, and cervical dysplasia) and another three discontinued the study drug due to EFV intolerance. CONCLUSIONS: This generic STR TDF/3TC/EFV is effective and well-tolerated. These findings lend support to the use of this generic STR as first-line antiretroviral therapy in resource-limited settings
Interest in the ‘Test and Treat’ strategy for HIV prevention among men who have sex with men living in Bangkok
Background: The current HIV epidemic in Thailand is primarily driven by new cases among men who have sex with men (MSM). HPTN052 study demonstrated 96% efficacy of immediate antiretroviral therapy (ART) to reduce HIV transmission among serodiscordant heterosexual couples. As a result, universal HIV testing and immediate ART has emerged as a strategy to reduce HIV transmission in certain at-risk populations. The acceptability of this strategy, however, is unknown in MSM. Methods: From August 2011-March 2012, we conducted a cross-sectional study using self-administered questionnaires to assess attitudes towards universal HIV testing and immediate ART among MSM VCT clients in Bangkok. Participants were asked to complete the questionnaires prior to and after knowing their HIV status. The study was approved by the Institutional Review Board of the Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Results: Of 342 MSM, the median age (IQR) was 26 (22–31) years, and 34.2% had bachelor's degree or higher. Previous HIV testing was reported by 69.9%, 35.2% of which had HIV testing annually. The most common reasons for previous HIV testing included perceived risk behaviors (63.6%), annual health checkup (26.4%), and partner's request (13.8%). Prior to receiving pre-test counseling, 74.4% expressed interest to get regular HIV testing. Health benefits from testing (59.6%), free testing (36.5%), and speedy service (35.7%) were the most common persuasive reasons to come for regular HIV testing. Longevity (73.1%) and prevention of HIV transmission to others (58.4%) were reasons for interest in immediate ART (if tested positive) program while costs (37.0%) and life-long burden (36.7%) were cited as main barriers. Among MSM who tested HIV-positive (n=45, 13.2%), the interest to participate in immediate ART program was very high both before and after knowing their HIV status (86.7% vs 93.3%, p=0.371). Among HIV-negative MSM, the interest to participate in regular HIV testing program significantly increased after knowing HIV status (83.4% vs 77.0%, p<0.001). Conclusions: MSM in Bangkok showed high level of interest in the “Test and Treat” strategy for HIV prevention. Knowing one's HIV status affected the interest to access regular HIV testing program