212 research outputs found

    Immunovirological outcomes and resistance patterns at 4 years of antiretroviral therapy use in HIV-infected patients in Cambodia

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    Objectives  To report immunovirological outcomes and resistance patterns in adults treated with triple combination antiretroviral therapy (cART) for 4 years in an HIV programme of Phnom Penh, Cambodia. Methods  It is a longitudinal study and cross-sectional evaluation of adults receiving cART for 4 years. CD4 cell counts and HIV-1 RNA were quantified, and resistance patterns were determined. Drug-related toxicity was assessed by clinicians and through laboratory testing. Results  After 4 years of cART start, the cumulative probability of retention in care was 0.80 and survival among patients not lost to follow-up was 0.85. A total of 349 patients (98% of eligible) participated in the cross-sectional evaluation. Ninety per cent were receiving first-line therapy, 29% stavudine- and 58% zidovudine-containing regimens (compared with 94% and 3% at cART initiation). Ninety-three per cent of patients were clinically asymptomatic, and severe lipodystrophy and dyslipidemia were diagnosed in 7.2% and 4.0%, respectively. Good treatment adherence was reported by 83% of patients. Median CD4 T-cell count was 410 cells/μl [IQR 290-511], and 90% of patients had >200 cells/μl. Only 15 (4%) patients had detectable HIV viral load (eight had <200 CD4 cells/μl), five had thymidine analogue mutations, and nine were resistant to two drug classes. In an intention-to-treat analysis, 26.1% (95% CI 22.0-30.5) of patients had failed first-line therapy. Conclusions  In this Cambodian cohort of adults who started cART at an advanced stage of HIV disease, we observed good clinical and immunovirological outcomes and self-reported treatment adherence at 4 years of therapy

    Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes: parasite risk factors that affect treatment outcomes for P. falciparum malaria after artemether-lumefantrine and artesunate-amodiaquine.

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    Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clearly defined. Individual patient data from 31 clinical trials were harmonized and pooled by using standardized methods from the WorldWide Antimalarial Resistance Network. Data for more than 7,000 patients were analyzed to assess relationships between parasite polymorphisms in pfcrt and pfmdr1 and clinically relevant outcomes after treatment with AL or ASAQ. Presence of the pfmdr1 gene N86 (adjusted hazards ratio = 4.74, 95% confidence interval = 2.29 - 9.78, P < 0.001) and increased pfmdr1 copy number (adjusted hazards ratio = 6.52, 95% confidence interval = 2.36-17.97, P < 0.001 : were significant independent risk factors for recrudescence in patients treated with AL. AL and ASAQ exerted opposing selective effects on single-nucleotide polymorphisms in pfcrt and pfmdr1. Monitoring selection and responding to emerging signs of drug resistance are critical tools for preserving efficacy of artemisinin combination therapies; determination of the prevalence of at least pfcrt K76T and pfmdr1 N86Y should now be routine

    "We give them threatening advice…": expectations of adherence to antiretroviral therapy and their consequences among adolescents living with HIV in rural Malawi.

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    INTRODUCTION: Many adolescents living with HIV in sub-Saharan Africa struggle to achieve optimal adherence to antiretroviral therapy (ART), but few studies have investigated how their treatment-taking decisions are influenced by their social interactions with providers, caregivers and community leaders. This study aims to explore the narratives that define expectations of adherence to ART among adolescents living with HIV in a rural Malawian setting. METHODS: Overall, 45 in-depth interviews were conducted in 2016 with adolescents living with HIV, caregivers, health workers and community leaders, and four group sessions using participatory tools were undertaken with adolescents. Interviews and group sessions were audio-recorded, transcribed and translated into English. Data were coded inductively and analysed thematically. RESULTS: Adolescents were given strict behavioural codes around optimal treatment adherence, which were often enforced through encouragement, persuasian and threats. In HIV clinics, some staff supported adolescents with broader concerns relating to living with HIV, but other measures to address sub-optimal adherence in HIV clinics were perceived by patients as punitive, including pill-counts and increased frequency of clinic visits. Community leaders felt responsible for young peoples' health, sometimes attempting to influence their treatment-taking by threatening to withdraw services, or to publically "out" those deemed to be non-adherent. At home, discussions with adolescents about HIV were often limited to dose reminders, and some caretakers resorted to physical punishment to ensure adherence. While some adolescents complied with strictly-enforced adherence rules, others demonstrated resistance by hiding missed doses, secretly throwing away drugs, or openly refusing to take them. CONCLUSIONS: The potential of young people to adhere to their ART may be undermined by restrictive messages and punitive approaches to enforce and control their engagement with treatment at home, in the clinic and in the wider community. Interventions should focus on creating safe spaces for adolescents to speak frankly about the adherence challenges that they face and support for caregivers including home-based interventions

    A Murine Model of High Dietary Histamine Intake: Impact on Histamine Contents and Release in Neural and Extraneural Tissues

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    Background: Histamine intolerance, a disorder due to impaired degradation of dietary histamine, is frequently associated with headaches, but the underlying pathophysiology is largely unknown; the sensitization of meningeal afferents appears likely. We approached this issue by examining histamine concentrations in different tissues and meningeal histamine release in a new mouse model of high-histamine diets. Methods: C57BL/6 mice of both sexes were fed with diets containing 3 or 9 g/kg histamine and compared to control groups. After 10–30 days, the histamine concentration was determined in plasma, samples of homogenized ileum, trigeminal ganglia, spinal medulla, and cerebellum using an ELISA. The histamine release from mast cells in the dura mater stimulated with compound 48/80 was also examined. Results: Animals supplied with high dietary histamine showed normal behavior and no signs of suffering. Compared with the controls, the histamine concentration was significantly higher in plasma and ileum of mice fed with 3 g/kg, highest in animals fed with 9 g/kg histamine. In addition, this group of animals showed also higher histamine concentrations in the trigeminal ganglion. The histamine release from the dura mater in mice supplied with 3 g/kg histamine was not significantly different to control animals, but the relative increase in stimulated release was lower in male animals of the high histamine group. Conclusions: High dietary histamine increases histamine levels in blood plasma and the gut, whereas the histamine content of neural tissues is not significantly influenced. The lowered stimulated release in animals subjected to high dietary histamine may indicate compensatory mechanisms.The present work was supported by DR Healthcare, a business Unit of AB Biotek Human Nutrition and Health from Associated British Foods (ABF), the Alexander von Humboldt Foundation (Research Group Linkage Program between the Institutes of Physiology of the FAU Erlangen-Nürnberg and the University of Szeged), and the Albert Szent-Györgyi Research Grant of the Albert Szent-Györgyi Medical School, University of Szeged.DR Healthcare, a business Unit of AB Biotek Human Nutrition and Health from Associated British Foods (ABF)the Alexander von Humboldt Foundationthe Albert Szent-Györgyi Research Grant of the Albert Szent-Györgyi Medical School, University of Szege

    Glycerol Trinitrate Acts Downstream of Calcitonin Gene-Related Peptide in Trigeminal Nociception—Evidence from Rodent Experiments with Anti-CGRP Antibody Fremanezumab

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    Calcitonin gene-related peptide (CGRP) and nitric oxide (NO) have been recognized as important mediators in migraine but their mechanisms of action and interaction have not been fully elucidated. Monoclonal anti-CGRP antibodies like fremanezumab are successful preventives of frequent migraine and can be used to study CGRP actions in preclinical experiments. Fremanezumab (30 mg/kg) or an isotype control monoclonal antibody was subcutaneously injected to Wistar rats of both sexes. One to several days later, glyceroltrinitrate (GTN, 5 mg/kg) mimicking nitric oxide (NO) was intraperitoneally injected, either once or for three consecutive days. The trigeminal ganglia were removed to determine the concentration of CGRP using an enzyme-linked immunosorbent assay (ELISA). In one series of experiments, the animals were trained to reach an attractive sugar solution, the access to which could be limited by mechanical or thermal barriers. Using a semi-automated registration system, the frequency of approaches to the source, the residence time at the source, and the consumed solution were registered. The results were compared with previous data of rats not treated with GTN. The CGRP concentration in the trigeminal ganglia was generally higher in male rats and tended to be increased in animals treated once with GTN, whereas the CGRP concentration decreased after repetitive GTN treatment. No significant difference in CGRP concentration was observed between animals having received fremanezumab or the control antibody. Animals treated with GTN generally spent less time at the source and consumed less sugar solution. Without barriers, there was no significant difference between animals having received fremanezumab or the control antibody. Under mechanical barrier conditions, all behavioral parameters tended to be reduced but animals that had received fremanezumab tended to be more active, partly compensating for the depressive effect of GTN. In conclusion, GTN treatment seems to increase the production of CGRP in the trigeminal ganglion independently of the antibodies applied, but repetitive GTN administration may deplete CGRP stores. GTN treatment generally tends to suppress the animals’ activity and increase facial sensitivity, which is partly compensated by fremanezumab through reduced CGRP signaling. If CGRP and NO signaling share the same pathway in sensitizing trigeminal afferents, GTN and NO may act downstream of CGRP to increase facial sensitivity.Hungarian National Research, Development and InnovationAlexander von Humboldt Foundation (Research Group Linkage Program between the Institutes of Physiology of the FAU Erlangen-Nürnberg and the University of Szeged

    Viral suppression and HIV-1 drug resistance 1 year after pragmatic transitioning to dolutegravir first-line therapy in Malawi: a prospective cohort study.

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    BACKGROUND Many countries are now replacing non-nucleoside reverse transcriptase inhibitor (NNRTI)-based first-line antiretroviral therapy (ART) with a regimen containing tenofovir disoproxil fumarate, lamivudine, and dolutegravir (TLD). Recognising laboratory limitations, Malawi opted to transition those on NNRTI-based first-line ART to TLD without viral load testing. We aimed to assess viral load and HIV drug resistance during 1 year following transition to TLD without previous viral load testing. METHODS In this prospective cohort study, we monitored 1892 adults transitioning from NNRTI-based first-line ART to the TLD regimen in the Médecins Sans Frontières-supported decentralised HIV programme in Chiradzulu District, Malawi. Eligible adults were enrolled between Jan 17 and May 11, 2019, at Ndunde and Milepa health centres, and between March 8 and May 11, 2019, at the Boma clinic. Viral load at the start of the TLD regimen was assessed retrospectively and measured at month 3, 6, and 12, and additionally at month 18 for those ever viraemic (viral load ≥50 copies per mL). Dolutegravir minimal plasma concentrations (Cmin) were determined for individuals with viraemia. Drug-resistance testing was done at the start of TLD regimen and at viral failure (viral load ≥50 copies per mL, followed by viral load ≥500 copies per mL; resistance defined as Stanford score ≥15). FINDINGS Of 1892 participants who transitioned to the TLD regimen, 101 (5·3%) were viraemic at TLD start. 89 of 101 had drug-resistance testing with 31 participants (34·8%) with Lys65Arg mutation, 48 (53·9%) with Met184Val/Ile, and 42 (40·4%) with lamivudine and tenofovir disoproxil fumerate dual resistance. At month 12 (in the per-protocol population), 1725 (97·9% [95% CI 97·1-98·5]) of 1762 had viral loads of less than 50 copies per mL, including 83 (88·3% [80·0-94·0]) of 94 of those who were viraemic at baseline. At month 18, 35 (97·2% [85·5-99·9]) of 36 who were viraemic at TLD start with lamivudine and tenofovir disoproxil fumarate resistance and 27 (81·8% [64·5-93·0]) of 33 of those viraemic at baseline without resistance had viral load suppression. 14 of 1838 with at least two viral load tests upon transitioning had viral failure (all with at least one dolutegravir Cmin value <640 ng/mL; active threshold), suggesting suboptimal adherence. High baseline viral load was associated with viral failure (adjusted odds ratio [aOR] 14·1 [2·3-87·4] for 1000 to <10 000 copies per mL; aOR 64·4 [19·3-215·4] for ≥10 000 copies per mL). Two people with viral failure had dolutegravir resistance at 6 months (Arg263Lys or Gly118Arg mutation), both were viraemic with lamivudine and tenofovir disoproxil fumarate resistance at baseline. INTERPRETATION High viral load suppression 1 year after introduction of the TLD regimen supports the unconditional transition strategy in Malawi. However, high pre-transition viral load, ongoing adherence challenges, and possibly existing nucleoside reverse transcriptase inhibitor resistance can lead to rapid development of dolutegravir resistance in a few individuals. This finding highlights the importance of viral load monitoring and dolutegravir-resistance surveillance after mass transitioning to the TLD regimen. FUNDING Médecins Sans Frontières. TRANSLATIONS For the French and Portuguese translations of the abstract see Supplementary Materials section

    'I saw it as a second chance': A qualitative exploration of experiences of treatment failure and regimen change among people living with HIV on second- and third-line antiretroviral therapy in Kenya, Malawi and Mozambique.

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    Increasing numbers of people living with HIV (PLHIV) in sub-Saharan Africa are experiencing failure of first-line antiretroviral therapy and transitioning onto second-line regimens. However, there is a dearth of research on their treatment experiences. We conducted in-depth interviews with 43 PLHIV on second- or third-line antiretroviral therapy and 15 HIV health workers in Kenya, Malawi and Mozambique to explore patients' and health workers' perspectives on these transitions. Interviews were audio-recorded, transcribed and translated into English. Data were coded inductively and analysed thematically. In all settings, experiences of treatment failure and associated episodes of ill-health disrupted daily social and economic activities, and recalled earlier fears of dying from HIV. Transitioning onto more effective regimens often represented a second (or third) chance to (re-)engage with HIV care, with patients prioritising their health over other aspects of their lives. However, many patients struggled to maintain these transformations, particularly when faced with persistent social challenges to pill-taking, alongside the burden of more complex regimens and an inability to mobilise sufficient resources to accommodate change. Efforts to identify treatment failure and support regimen change must account for these patients' unique illness and treatment histories, and interventions should incorporate tailored counselling and social and economic support

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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