95 research outputs found

    Genetic variability of hepatitis C virus before and after combined therapy of interferon plus ribavirin

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    We present an analysis of the selective forces acting on two hepatitis C virus genome regions previously postulated to be involved in the viral response to combined antiviral therapy. One includes the three hypervariable regions in the envelope E2 glycoprotein, and the other encompasses the PKR binding domain and the V3 domain in the NS5A region. We used a cohort of 22 non-responder patients to combined therapy (interferon alpha-2a plus ribavirin) for which samples were obtained before initiation of therapy and after 6 or/and 12 months of treatment. A range of 25-100 clones per patient, genome region and time sample were sequenced. These were used to detect general patterns of adaptation, to identify particular adaptation mechanisms and to analyze the patterns of evolutionary change in both genome regions. These analyses failed to detect a common adaptive mechanism for the lack of response to antiviral treatment in these patients. On the contrary, a wide range of situations were observed, from patients showing no positively selected sites to others with many, and with completely different topologies in the reconstructed phylogenetic trees. Altogether, these results suggest that viral strategies to evade selection pressure from the immune system and antiviral therapies do not result from a single mechanism and they are likely based on a range of different alternatives, in which several different changes, or their combination, along the HCV genome confer viruses the ability to overcome strong selective [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]

    H5N1 Influenza Vaccine Formulated with AS03A Induces Strong Cross-Reactive and Polyfunctional CD4 T-Cell Responses

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    Objective Adjuvantation of an H5N1 split-virion influenza vaccine with AS03(A) substantially reduces the antigen dose required to produce a putatively protective humoral response and promotes cross-clade neutralizing responses. We determined the effect of adjuvantation on antibody persistence and B- and T-cell-mediated immune responses. Methods Two vaccinations with a split-virion A/Vietnam/1194/2004 (H5N1, clade 1) vaccine containing 3.75-30 mu g hemagglutinin and formulated with or without adjuvant were administered to groups of 50 volunteers aged 18-60 years. Results Adjuvantation of the vaccine led to better persistence of neutralizing and hemagglutination-inhibiting antibodies and higher frequencies of antigen-specific memory B cells. Cross-reactive and polyfunctional H5N1-specific CD4 T cells were detected at baseline and were amplified by vaccination. Expansion of CD4 T cells was enhanced by adjuvantation. Conclusion Formulation of the H5N1 vaccine with AS03(A) enhances antibody persistence and induces stronger T- and B-cell responses. The cross-clade T-cell immunity indicates that the adjuvanted vaccine primes individuals to respond to either infection and/or subsequent vaccination with strains drifted from the primary vaccine strain

    Humoral and Cell-Mediated Immunity to Pandemic H1N1 Influenza in a Canadian Cohort One Year Post-Pandemic: Implications for Vaccination

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    We evaluated a cohort of Canadian donors for T cell and antibody responses against influenza A/California/7/2009 (pH1N1) at 8-10 months after the 2nd pandemic wave by flow cytometry and microneutralization assays. Memory CD8 T cell responses to pH1N1 were detectable in 58% (61/105) of donors. These responses were largely due to cross-reactive CD8 T cell epitopes as, for those donors tested, similar recall responses were obtained to A/California 2009 and A/PR8 1934 H1N1 Hviruses. Longitudinal analysis of a single infected individual showed only a small and transient increase in neutralizing antibody levels, but a robust CD8 T cell response that rose rapidly post symptom onset, peaking at 3 weeks, followed by a gradual decline to the baseline levels seen in a seroprevalence cohort post-pandemic. The magnitude of the influenza-specific CD8 T cell memory response at one year post-pandemic was similar in cases and controls as well as in vaccinated and unvaccinated donors, suggesting that any T cell boosting from infection was transient. Pandemic H1-specific antibodies were only detectable in approximately half of vaccinated donors. However, those who were vaccinated within a few months following infection had the highest persisting antibody titers, suggesting that vaccination shortly after influenza infection can boost or sustain antibody levels. For the most part the circulating influenza-specific T cell and serum antibody levels in the population at one year post-pandemic were not different between cases and controls, suggesting that natural infection does not lead to higher long term T cell and antibody responses in donors with pre-existing immunity to influenza. However, based on the responses of one longitudinal donor, it is possible for a small population of pre-existing cross-reactive memory CD8 T cells to expand rapidly following infection and this response may aid in viral clearance and contribute to a lessening of disease severity

    Pegylated Interferon and Ribavirin Dosing Strategies to Enhance Sustained Virologic Response

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    Hepatitis C virus (HCV) affects about 170 million people worldwide and is the most common chronic blood borne infection in the United States. Since the advent of blood screening protocols in the early 1990s, injection drug use has become the leading cause of infection. Hepatitis C can have both hepatic and nonhepatic manifestations of infection. Hepatic manifestations include hepatic fibrosis, cirrhosis, liver cancer, and liver failure. The standard treatment for chronic HCV is combination therapy with pegylated interferon-α and ribavirin. Although pegylated interferon and ribavirin has been used against HCV for close to a decade, advances in therapy have centered on doses and treatment durations. There has been increasing interest in applying on-treatment response or viral kinetics to predict antiviral response rates and shape therapeutic intervention. Protease inhibitors are a promising adjuvant to combination therapy, but their efficacy and safety are still under investigation

    Collaborating in the context of co-location: a grounded theory study

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    BACKGROUND: Most individuals with mental health concerns seek care from their primary care provider, who may lack comfort, knowledge, and time to provide care. Interprofessional collaboration between providers improves access to primary mental health services and increases primary care providers’ comfort offering these services. Building and sustaining interprofessional relationships is foundational to collaborative practice in primary care settings. However, little is known about the relationship building process within these collaborative relationships. The purpose of this grounded theory study was to gain a theoretical understanding of the interprofessional collaborative relationship-building process to guide health care providers and leaders as they integrate mental health services into primary care settings. METHODS: Forty primary and mental health care providers completed a demographic questionnaire and participated in either an individual or group interview. Interviews were audio-recorded and transcribed verbatim. Transcripts were reviewed several times and then individually coded. Codes were reviewed and similar codes were collapsed to form categories using using constant comparison. All codes and categories were discussed amongst the researchers and the final categories and core category was agreed upon using constant comparison and consensus. RESULTS: A four-stage developmental interprofessional collaborative relationship-building model explained the emergent core category of Collaboration in the Context of Co-location. The four stages included 1) Looking for Help, 2) Initiating Co-location, 3) Fitting-in, and 4) Growing Reciprocity. A patient-focus and communication strategies were essential processes throughout the interprofessional collaborative relationship-building process. CONCLUSIONS: Building interprofessional collaborative relationships amongst health care providers are essential to delivering mental health services in primary care settings. This developmental model describes the process of how these relationships are co-created and supported by the health care region. Furthermore, the model emphasizes that all providers must develop and sustain a patient-focus and communication strategies that are flexible. Applying this model, health care providers can guide the creation and sustainability of primary care interprofessional collaborative relationships. Moreover, this model may guide health care leaders and policy makers as they initiate interprofessional collaborative practice in other health care settings

    On the Role of Faith in Sustainability Management: A Conceptual Model and Research Agenda

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    International audienceThe objective of this article is to develop a faith development perspective on corporate sustainability. A firm’s management of sustainability is arguably determined by the way decision-makers relate to the other and the natural environment, and this relationship is fundamentally shaped by faith. This study advances theoretical understanding of the approach managers take on sustainability issues by explaining how four distinct phases of faith development—improvidence, obedience, irreverence and providence—determine a manager’s disposition towards sustainability. Combining insights from intentional and relational faith development theories, the analysis reveals that a manager’s faith disposition can be measured according to four interrelated process criteria: (1) connectivity as a measure of a manager’s actual engagement and activities aimed at relating to sustainability; (2) inclusivity as a measure of who and what is included or excluded in a manager’s moral consideration; (3) emotional affinity as a measure of a manager’s sensitivity and affection towards the well-being of others and ecological welfare; and (4) reciprocity as a measure of the degree to which a manager is rewarded for responding to the needs and concerns of ‘Others’, mainly in the form of a positive emotional (and relational) stimulus. The conceptual model consolidates earlier scholarly works on the psychological drivers of sustainability management by illuminating our search for a process of faith development that connects with an increasingly complex understanding of the role of business in society

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

    Distributed Machine Learning

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