494 research outputs found

    Deep-sequencing of viral genomes from a large and diverse cohort of treatment-naive HIV-infected persons shows associations between intrahost genetic diversity and viral load.

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    BACKGROUND Infection with human immunodeficiency virus type 1 (HIV) typically results from transmission of a small and genetically uniform viral population. Following transmission, the virus population becomes more diverse because of recombination and acquired mutations through genetic drift and selection. Viral intrahost genetic diversity remains a major obstacle to the cure the HIV; however, the association between intrahost diversity and disease progression markers has not been investigated in large and diverse cohorts for which the majority of the genome has been deep-sequenced. Viral load (VL) is a key progression marker and understanding of its relationship to viral intrahost genetic diversity could help design future strategies for HIV monitoring and treatment. METHODS We analysed deep-sequenced viral genomes from 2,650 treatment-naive HIV-infected persons to measure the intrahost genetic diversity of 2,447 genomic codon positions as calculated by Shannon entropy. We tested for associations between VL and amino acid (AA) entropy accounting for sex, age, race, duration of infection, and HIV population structure. RESULTS We confirmed that the intrahost genetic diversity is highest in the env gene. Furthermore, we showed that mean Shannon entropy is significantly associated with VL, especially in infections of >24 months duration. We identified 16 significant associations between VL (p-value<2.0x10-5) and Shannon entropy at AA positions which in our association analysis explained 13% of the variance in VL. Finally, equivalent analysis based on variation in HIV consensus sequences explained only 2% of VL variance. CONCLUSIONS Our results elucidate that viral intrahost genetic diversity is associated with VL and could be used as a better disease progression marker than HIV consensus sequence variants, especially in infections of longer duration. We emphasize that viral intrahost diversity should be considered when studying viral genomes and infection outcomes. TRIAL REGISTRATION Samples included in this study were derived from participants who consented in the clinical trial, START (NCT00867048) (23), run by the International Network for Strategic Initiatives in Global HIV Trials (INSIGHT). All the participant sites are listed here: http://www.insight-trials.org/start/my_phpscript/participating.php?by=site

    Comparison of five specific assays for determination of dabigatran plasma concentrations in patients enrolled in the START-Laboratory Register

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    Introduction: Several specific assays are commercially available to determine dabigatran anticoagulant activity. Aims of this multicenter and multiplatform study were to compare five methods for dabigatran measurement and investigate their performances in the low concentration range. Methods: Dabigatran levels were analyzed in 295 plasma samples from patients enrolled in the START-Laboratory Register by the following methods using dedicated calibrators and controls: STA-ECA II (Diagnostica Stago), standard and low range Hemoclot Thrombin Inhibitors (Hyphen BioMed), Direct Thrombin Inhibitor Assay (Instrumentation Laboratory), Direct Thrombin Inhibitor Assay (Siemens), Technoclot DTI (Technoclone). Results: Methods showed variable agreement with the Hemoclot Thrombin Inhibitors assay used as reference test, with modest under- or overestimations (Bland-Altman bias from −17.3 to 4.0 ng/mL). Limits of detection and quantification varied depending on the assay (4-52 and 7-82 ng/mL, respectively). Between-run precision and accuracy were good for all methods for both quality control levels. Assay's repeatability assessed at very low dabigatran concentrations (from 10 to 60 ng/mL) was also acceptable, variability generally increased at lower drug levels. Conclusion: The five dabigatran-specific assays evaluated in this study provided reliable assessment of dabigatran plasma levels, although showing different performances. © 2018 The Authors. International Journal of Laboratory Hematology Published by John Wiley & Sons Lt

    Derivation of a Protein Risk Score for Cardiovascular Disease Among a Multiracial and Multiethnic HIV+ Cohort

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    Background Cardiovascular disease risk prediction models underestimate CVD risk in people living with HIV (PLWH). Our goal is to derive a risk score based on protein biomarkers that could be used to predict CVD in PLWH. Methods and Results In a matched case-control study, we analyzed normalized protein expression data for participants enrolled in 1 of 4 trials conducted by INSIGHT (International Network for Strategic Initiatives in Global HIV Trials). We used dimension reduction, variable selection and resampling methods, and multivariable conditional logistic regression models to determine candidate protein biomarkers and to generate a protein score for predicting CVD in PLWH. We internally validated our findings using bootstrap. A protein score that was derived from 8 proteins (including HGF [hepatocyte growth factor] and interleukin-6) was found to be associated with an increased risk of CVD after adjustment for CVD and HIV factors (odds ratio: 2.17 [95% CI: 1.58-2.99]). The protein score improved CVD prediction when compared with predicting CVD risk using the individual proteins that comprised the protein score. Individuals with a protein score above the median score were 3.10 (95% CI, 1.83-5.41) times more likely to develop CVD than those with a protein score below the median score. Conclusions A panel of blood biomarkers may help identify PLWH at a high risk for developing CVD. If validated, such a score could be used in conjunction with established factors to identify CVD at-risk individuals who might benefit from aggressive risk reduction, ultimately shedding light on CVD pathogenesis in PLWH

    Experimental evidence for 56Ni-core breaking from the low-spin structure of the N=Z nucleus 58Cu

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    Low-spin states in the odd-odd N=Z nucleus 58Cu were investigated with the 58Ni(p,n gamma)58Cu fusion evaporation reaction at the FN-tandem accelerator in Cologne. Seventeen low spin states below 3.6 MeV and 17 new transitions were observed. Ten multipole mixing ratios and 17 gamma-branching ratios were determined for the first time. New detailed spectroscopic information on the 2+,2 state, the Isobaric Analogue State (IAS) of the 2+,1,T=1 state of 58Ni, makes 58Cu the heaviest odd-odd N=Z nucleus with known B(E2;2+,T=1 --> 0+,T=1) value. The 4^+ state at 2.751 MeV, observed here for the first time, is identified as the IAS of the 4+,1,T=1 state in 58Ni. The new data are compared to full pf-shell model calculations with the novel GXPF1 residual interaction and to calculations within a pf5/2 configurational space with a residual surface delta interaction. The role of the 56Ni core excitations for the low-spin structure in 58Cu is discussed.Comment: 15 pages, 7 figures, submitted to Phys. Rev.

    An exploratory cluster randomised controlled trial of knowledge translation strategies to support evidence-informed decision-making in local governments (The KT4LG study)

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    Background: Childhood overweight and obesity is the most prevalent and, arguably, politically complex child health problem internationally. Governments, communities and industry have important roles to play, and are increasingly expected to deliver an evidence-informed system-wide prevention program. However, efforts are impeded by a lack of organisational access to and use of research evidence. This study aims to identify feasible, acceptable and ideally, effective knowledge translation (KT) strategies to increase evidence-informed decision making in local governments, within the context of childhood obesity prevention as a national policy priority.Methods/Design: This paper describes the methods for KT4LG, a cluster randomised controlled trial which is exploratory in nature, given the limited evidence base and methodological advances. KT4LG aims to examine a program of KT strategies to increase the use of research evidence in informing public health decisions in local governments. KT4LG will also assess the feasibility and acceptability of the intervention. The intervention program comprises a facilitated program of evidence awareness, access to tailored research evidence, critical appraisal skills development, networking and evidence summaries and will be compared to provision of evidence summaries alone in the control program. 28 local governments were randomised to intervention or control, using computer generated numbers, stratified by budget tertile (high, medium or low). Questionnaires will be used to measure impact, costs, and outcomes, and key informant interviews will be used to examine processes, feasibility, and experiences. Policy tracer studies will be included to examine impact of intervention on policies within relevant government policy documents.Discussion: Knowledge translation intervention studies with a focus on public health and prevention are very few in number. Thus, this study will provide essential data on the experience of program implementation and evaluation of a system-integrated intervention program employed within the local government public health context. Standardised programs of system, organisational and individual KT strategies have not been described or rigorously evaluated. As such, the findings will make a significant contribution to understanding whether a facilitated program of KT strategies hold promise for facilitating evidence-informed public health decision making within complex multisectoral government organisations.<br /

    Creating a public space and dialogue on sexuality and rights: a case study from Bangladesh

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    This article describes and analyses a research based engagement by a university school of public health in Bangladesh aimed at raising public debate on sexuality and rights and making issues such as discrimination more visible to policy makers and other key stakeholders in a challenging context. The impetus for this work came from participation in an international research programme with a particular interest in bridging international and local understandings of sexual and reproductive rights. The research team worked to create a platform to broaden discussions on sexuality and rights by building on a number of research activities on rural and urban men’s and women’s sexual health concerns, and on changing concepts of sexuality and understandings of sexual rights among specific population groups in Dhaka city, including sexual minorities. Linked to this on-going process of improving the evidence base, there has been a series of learning and capacity building activities over the last four years consisting of training workshops, meetings, conferences and dialogues. These brought together different configurations of stakeholders – members of sexual minorities, academics, service providers, advocacy organisations, media and policy makers. This process contributed to developing more effective advocacy strategies through challenging representations of sexuality and rights in the public domain. Gradually, these efforts brought visibility to hidden or stigmatised sexuality and rights issues through interim outcomes that have created important steps towards changing attitudes and policies. These included creating safe spaces for sexual minorities to meet and strategise, development of learning materials for university students and engagement with legal rights groups on sexual rights. Through this process, it was found to be possible to create a public space and dialogue on sexuality and rights in a conservative and challenging environment like Bangladesh by bringing together a diverse group of stakeholders to successfully challenge representations of sexuality in the public arena. A further challenge for BRAC University has been to assess its role as a teaching and research organisation, and find a balance between the two roles of research and activism in doing work on sexuality issues in a very sensitive political context

    Tofacitinib versus methotrexate in rheumatoid arthritis

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    Background : Methotrexate is the most frequently used first-line antirheumatic drug. We report the findings of a phase 3 study of monotherapy with tofacitinib, an oral Janus kinase inhibitor, as compared with methotrexate monotherapy in patients with rheumatoid arthritis who had not previously received methotrexate or therapeutic doses of methotrexate. Methods : We randomly assigned 958 patients to receive 5 mg or 10 mg of tofacitinib twice daily or methotrexate at a dose that was incrementally increased to 20 mg per week over 8 weeks; 956 patients received a study drug. The coprimary end points at month 6 were the mean change from baseline in the van der Heijde modified total Sharp score (which ranges from 0 to 448, with higher scores indicating greater structural joint damage) and the proportion of patients with an American College of Rheumatology (ACR) 70 response (>= 70% reduction in the number of both tender and swollen joints and >= 70% improvement in three of five other criteria: the patient's assessment of pain, level of disability, C-reactive protein level or erythrocyte sedimentation rate, global assessment of disease by the patient, and global assessment of disease by the physician). Results : Mean changes in the modified total Sharp score from baseline to month 6 were significantly smaller in the tofacitinib groups than in the methotrexate group, but changes were modest in all three groups (0.2 points in the 5-mg tofacitinib group and <0.1 point in the 10-mg tofacitinib group, as compared with 0.8 points in the methotrexate group [ P<0.001 for both comparisons]). Among the patients receiving tofacitinib, 25.5% in the 5-mg group and 37.7% in the 10-mg group had an ACR 70 response at month 6, as compared with 12.0% of patients in the methotrexate group (P<0.001 for both comparisons). Herpes zoster developed in 31 of 770 patients who received tofacitinib (4.0%) and in 2 of 186 patients who received methotrexate (1.1%). Confirmed cases of cancer (including three cases of lymphoma) developed in 5 patients who received tofacitinib and in 1 patient who received methotrexate. Tofacitinib was associated with increases in creatinine levels and in low-density and high-density lipoprotein cholesterol levels. Conclusions : In patients who had not previously received methotrexate or therapeutic doses of methotrexate, tofacitinib monotherapy was superior to methotrexate in reducing signs and symptoms of rheumatoid arthritis and inhibiting the progression of structural joint damage. The benefits of tofacitinib need to be considered in the context of the risks of adverse events

    Human immunotypes impose selection on viral genotypes through viral epitope specificity

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    BACKGROUND: Understanding the genetic interplay between human hosts and infectious pathogens is crucial for how we interpret virulence factors. Here, we tested for associations between HIV and host genetics, and interactive genetic effects on viral load (VL) in HIV+ ART-naive clinical trial participants. METHODS: HIV genomes were sequenced and the encoded amino acid (AA) variants were associated with VL, human single nucleotide polymorphisms (SNPs) and imputed HLA alleles, using generalized linear models with Bonferroni correction. RESULTS: Human (388,501 SNPs) and HIV (3,010 variants) genetic data was available for 2,122 persons. Four HIV variants were associated with VL (p-values<1.66×10 -5). Twelve HIV variants were associated with a range of 1-512 human SNPs (p-value<4.28×10 -11). We found 46 associations between HLA alleles and HIV variants (p-values<1.29×10 -7). We found HIV variants and immunotypes when analyzed separately, were associated with lower VL, whereas the opposite was true when analyzed in concert. Epitope binding prediction showed HLA alleles to be weaker binders of associated HIV AA variants relative to alternative variants on the same position. CONCLUSIONS: Our results show the importance of immunotype specificity on viral antigenic determinants, and the identified genetic interplay puts emphasis that viral and human genetics should be studied in the context of each other

    Early Antiretroviral Therapy at High CD4 Counts Does Not Improve Arterial Elasticity: A Substudy of the Strategic Timing of AntiRetroviral Treatment (START) Trial

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    BACKGROUND: Both human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) may increase cardiovascular disease (CVD) risk. Vascular function assessments can be used to study CVD pathogenesis. We compared the effect of immediate versus deferred ART initiation at CD4 counts >500 cells/mm(3) on small arterial elasticity (SAE) and large artery elasticity (LAE). METHODS: Radial artery blood pressure waveforms were recorded noninvasively. Small arterial elasticity and LAE were derived from analysis of the diastolic pulse waveform. Randomized treatment groups were compared with linear models at each visit and longitudinal mixed models. RESULTS: Study visits involved 332 participants in 8 countries: mean (standard deviation [SD]) age 35 (10), 70% male, 66% nonwhite, 30% smokers, and median CD4 count 625 cells/mm(3) and 10-year Framingham risk score for CVD 1.7%. Mean (SD) SAE and LAE values at baseline were 7.3 (2.9) mL/mmHg × 100 and 16.6 (4.1) mL/mmHg × 10, respectively. Median time on ART was 47 and 12 months in the immediate and deferred ART groups, respectively. The treatment groups did not demonstrate significant within-person changes in SAE or LAE during the follow-up period, and there was no difference in mean change from baseline between treatment groups. The lack of significant differences persisted after adjustment, when restricted to early or late changes, after censoring participants in deferred group who started ART, and among subgroups defined by CVD and HIV risk factors. CONCLUSIONS: Among a diverse global population of HIV-positive persons with high CD4 counts, these randomized data suggest that ART treatment does not have a substantial influence on vascular function among younger HIV-positive individuals with preserved immunity
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