586 research outputs found

    HIV self-testing intervention experiences and kit usability: results from a qualitative study among men who have sex with men in the SELPHI (Self-Testing Public Health Intervention) randomized controlled trial in England and Wales.

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    OBJECTIVES: SELPHI (HIV Self-Testing Public Health Intervention) is the largest randomized controlled trial (RCT) of HIV self-testing (HIVST) in a high-income setting to date, and has recruited 10 000 men who have sex with men (cis- and transgender) and transgender women who have sex with men. This qualitative substudy aimed to explore how those utilizing self-tests experience HIVST and the implications for further intervention development and scale-up. This is the first qualitative study in Europe investigating experiences of HIVST among intervention users, and the first globally examining the experience of using blood-based HIVST. METHODS: Thirty-seven cisgender MSM SELPHI participants from across England and Wales were purposively recruited to the substudy, in which semi-structured interviews were used to explore testing history, HIVST experiences and intervention preferences. Interviews were audio-recorded, transcribed and analysed through a framework analysis. RESULTS: Men accessed the intervention because HIVST reduced barriers related to convenience, stigma and privacy concerns. Emotional responses had direct links to acceptability. Supportive intervention components increased engagement with testing and addressed supportive concerns. HIVST facilitated more frequent testing, with the potential to reduce sexually transmitted infection (STI) screening frequency. Substudy participants with an HIV-positive result (n = 2) linked to care promptly and reported very high acceptability. Minor adverse outcomes (n = 2; relationship discord and fainting) did not reduce acceptability. Ease of use difficulties were with the lancet and the test processing stage. CONCLUSIONS: Intervention components shaped acceptability, particularly in relation to overcoming a perceived lack of support. The intervention was broadly acceptable and usable; participants expressed an unexpected degree of enthusiasm for HIVST, including those with HIV-positive results and individuals with minor adverse outcomes

    Discovery of Quinazolines That Activate SOS1-Mediated Nucleotide Exchange on RAS.

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    Proteins in the RAS family are important regulators of cellular signaling and, when mutated, can drive cancer pathogenesis. Despite considerable effort over the last 30 years, RAS proteins have proven to be recalcitrant therapeutic targets. One approach for modulating RAS signaling is to target proteins that interact with RAS, such as the guanine nucleotide exchange factor (GEF) son of sevenless homologue 1 (SOS1). Here, we report hit-to-lead studies on quinazoline-containing compounds that bind to SOS1 and activate nucleotide exchange on RAS. Using structure-based design, we refined the substituents attached to the quinazoline nucleus and built in additional interactions not present in the initial HTS hit. Optimized compounds activate nucleotide exchange at single-digit micromolar concentrations in vitro. In HeLa cells, these quinazolines increase the levels of RAS-GTP and cause signaling changes in the mitogen-activated protein kinase/extracellular regulated kinase (MAPK/ERK) pathway

    Role of mitochondrial raft-like microdomains in the regulation of cell apoptosis

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    Lipid rafts are envisaged as lateral assemblies of specific lipids and proteins that dissociate and associate rapidly and form functional clusters in cell membranes. These structural platforms are not confined to the plasma membrane; indeed lipid microdomains are similarly formed at subcellular organelles, which include endoplasmic reticulum, Golgi and mitochondria, named raft-like microdomains. In addition, some components of raft-like microdomains are present within ER-mitochondria associated membranes. This review is focused on the role of mitochondrial raft-like microdomains in the regulation of cell apoptosis, since these microdomains may represent preferential sites where key reactions take place, regulating mitochondria hyperpolarization, fission-associated changes, megapore formation and release of apoptogenic factors. These structural platforms appear to modulate cytoplasmic pathways switching cell fate towards cell survival or death. Main insights on this issue derive from some pathological conditions in which alterations of microdomains structure or function can lead to severe alterations of cell activity and life span. In the light of the role played by raft-like microdomains to integrate apoptotic signals and in regulating mitochondrial dynamics, it is conceivable that these membrane structures may play a role in the mitochondrial alterations observed in some of the most common human neurodegenerative diseases, such as Amyotrophic lateral sclerosis, Huntington's chorea and prion-related diseases. These findings introduce an additional task for identifying new molecular target(s) of pharmacological agents in these pathologies

    Understanding the impact of antibiotic therapies on the respiratory tract resistome: A novel pooled-template metagenomic sequencing strategy

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    Determining the effects of antimicrobial therapies on airway microbiology at a population-level is essential. Such analysis allows, for example, surveillance of antibiotic-induced changes in pathogen prevalence, the emergence and spread of antibiotic resistance, and the transmission of multi-resistant organisms. However, current analytical strategies for understanding these processes are limited. Culture- and PCR-based assays for specific microbes require the a priori selection of targets, while antibiotic sensitivity testing typically provides no insight into either the molecular basis of resistance, or the carriage of resistance determinants by the wider commensal microbiota. Shotgun metagenomic sequencing provides an alternative approach that allows the microbial composition of clinical samples to be described in detail, including the prevalence of resistance genes and virulence traits. While highly informative, the application of metagenomics to large patient cohorts can be prohibitively expensive. Using sputum samples from a randomised placebo-controlled trial of erythromycin in adults with bronchiectasis, we describe a novel, cost-effective strategy for screening patient cohorts for changes in resistance gene prevalence. By combining metagenomic screening of pooled DNA extracts with validatory quantitative PCR-based analysis of candidate markers in individual samples, we identify population-level changes in the relative abundance of specific macrolide resistance genes. This approach has the potential to provide an important adjunct to current analytical strategies, particularly within the context of antimicrobial clinical trials

    Obstructed Labor and Caesarean Delivery: The Cost and Benefit of Surgical Intervention

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    Background: Although advances in the reduction of maternal mortality have been made, up to 273,000 women will die this year from obstetric etiologies. Obstructed labor (OL), most commonly treated with Caesarean delivery, has been identified as a major contributor to global maternal morbidity and mortality. We used economic and epidemiological modeling to estimate the cost per disability-adjusted life-year (DALY) averted and benefit-cost ratio of treating OL with Caesarean delivery for 49 countries identified as providing an insufficient number of Caesarean deliveries to meet demand. Methods and Findings Using publicly available data and explicit economic assumptions, we estimated that the cost per DALY (3,0,0) averted for providing Caesarean delivery for OL ranged widely, from 251perDALYavertedinMadagascarto251 per DALY averted in Madagascar to 3,462 in Oman. The median cost per DALY averted was $304. Benefit-cost ratios also varied, from 0.6 in Zimbabwe to 69.9 in Gabon. The median benefit-cost ratio calculated was 6.0. The main limitation of this study is an assumption that lack of surgical capacity is the main factor responsible for DALYs from OL. Conclusions: Using the World Health Organization's cost-effectiveness standards, investing in Caesarean delivery can be considered “highly cost-effective” for 48 of the 49 countries included in this study. Furthermore, in 46 of the 49 included countries, the benefit-cost ratio was greater than 1.0, implying that investment in Caesarean delivery is a viable economic proposition. While Caesarean delivery alone is not sufficient for combating OL, it is necessary, cost-effective by WHO standards, and ultimately economically favorable in the vast majority of countries included in this study

    Using systems science to understand the determinants of inequities in healthy eating

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    Introduction: Systems thinking has emerged in recent years as a promising approach to understanding and acting on the prevention and amelioration of non-communicable disease. However, the evidence on inequities in non-communicable diseases and their risks factors, particularly diet, has not been examined from a systems perspective. We report on an approach to developing a system oriented policy actor perspective on the multiple causes of inequities in healthy eating. Methods: Collaborative conceptual modelling workshops were held in 2015 with an expert group of representatives from government, non-government health organisations and academia in Australia. The expert group built a systems model using a system dynamics theoretical perspective. The model developed from individual mind maps to pair blended maps, before being finalised as a causal loop diagram. Results: The work of the expert stakeholders generated a comprehensive causal loop diagram of the determinants of inequity in healthy eating (the HE2Diagram). This complex dynamic system has seven sub-systems: (1) food supply and environment; (2) transport; (3) housing and the built environment; (4) employment; (5) social protection; (6) health literacy; and (7) food preferences. Discussion: The HE2causal loop diagram illustrates the complexity of determinants of inequities in healthy eating. This approach, both the process of construction and the final visualisation, can provide the basis for planning the prevention and amelioration of inequities in healthy eating that engages with multiple levels of causes and existing policies and programs

    Role of complement and antibodies in controlling infection with pathogenic simian immunodeficiency virus (SIV) in macaques vaccinated with replication-deficient viral vectors

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    <p>Abstract</p> <p>Background</p> <p>We investigated the interplay between complement and antibodies upon priming with single-cycle replicating viral vectors (SCIV) encoding SIV antigens combined with Adeno5-SIV or SCIV pseudotyped with murine leukemia virus envelope boosting strategies. The vaccine was applied via spray-immunization to the tonsils of rhesus macaques and compared with systemic regimens.</p> <p>Results</p> <p>Independent of the application regimen or route, viral loads were significantly reduced after challenge with SIVmac239 (p < 0.03) compared to controls. Considerable amounts of neutralizing antibodies were induced in systemic immunized monkeys. Most of the sera harvested during peak viremia exhibited a trend with an inverse correlation between complement C3-deposition on viral particles and plasma viral load within the different vaccination groups. In contrast, the amount of the observed complement-mediated lysis did not correlate with the reduction of SIV titres.</p> <p>Conclusion</p> <p>The heterologous prime-boost strategy with replication-deficient viral vectors administered exclusively via the tonsils did not induce any neutralizing antibodies before challenge. However, after challenge, comparable SIV-specific humoral immune responses were observed in all vaccinated animals. Immunization with single cycle immunodeficiency viruses mounts humoral immune responses comparable to live-attenuated immunodeficiency virus vaccines.</p

    Bioinformatics Analysis of Macrophages Exposed to Porphyromonas gingivalis: Implications in Acute vs. Chronic Infections

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    BACKGROUND. Periodontitis is the most common human infection affecting tooth-supporting structures. It was shown to play a role in aggravating atherosclerosis. To deepen our understanding of the pathogenesis of this disease, we exposed human macrophages to an oral bacteria, Porphyromonas gingivalis (P. gingivalis), either as live bacteria or its LPS or fimbria. Microarray data from treated macrophages or control cells were analyzed to define molecular signatures. Changes in genes identified in relevant pathways were validated by RT-PCR. METHODOLOGY/PRINCIPAL FINDINGS. We focused our analysis on three important groups of genes. Group PG (genes differentially expressed by live bacteria only); Group LFG (genes differentially expressed in response to exposure to LPS and/or FimA); Group CG (core gene set jointly activated by all 3 stimulants). A total of 842 macrophage genes were differentially expressed in at least one of the three conditions compared to naïve cells. Using pathway analysis, we found that group CG activates the initial phagocytosis process and induces genes relevant to immune response, whereas group PG can de-activate the phagocytosis process associated with phagosome-lysosome fusion. LFG mostly affected RIG-I-like receptor signaling pathway. CONCLUSION/SIGNIFICANCE. In light of the fact that acute infections involve live bacteria while chronic infections involve a combination of live bacteria and their byproducts, group PG could represent acute P. gingivalis infection while group LFG could represent chronic P. gingivalis infection. Group CG may be associated with core immune pathways, triggered irrespective of the specific stimulants and indispensable to mount an appropriate immune response. Implications in acute vs. chronic infection are discussed.National Institutes of Health (R01 DE014079, DE15989, HL7680

    Deficit of social cognition in subjects with surgically treated frontal lobe lesions and in subjects affected by schizophrenia

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    The ability of humans to predict and explain other people’s behaviour by attributing independent mental states such as desires and beliefs to them, is considered to be due to our ability to construct a “Theory of Mind”. Recently, several neuroimaging studies have implicated the medial frontal lobes as playing a critical role in a dedicated “mentalizing” or “Theory of Mind” network in the human brain. In this study we compare the performance of patients with right and left medial prefrontal lobe lesions in theory of mind and in social cognition tasks, with the performance of people with schizophrenia. We report a similar social cognitive profile between patients with prefrontal lobe lesions and schizophrenic subjects in terms of understanding of false beliefs, in understanding social situations and in using tactical strategies. These findings are relevant for the functional anatomy of “Theory of Mind”
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