RESUMO
Although many HIV-1-specific CD8+ T cell epitopes have been identified and used in various HIV-1 studies, most of these epitopes were derived from HIV-1 subtypes B and C. Only 17 well-defined epitopes, none of which were protective, have been identified for subtype A/E infection. The roles of HIV-1-specific T cells have been rarely analyzed for subtype A/E infection. In this study, we identified six novel HLA-B*15:02-restricted optimal HIV-1 subtype A/E epitopes and then analyzed the presentation of these epitopes by HIV-1 subtype A/E virus-infected cells and the T cell responses to these epitopes in treatment-naive HIV-1 subtype A/E-infected HLA-B*15:02+ Vietnamese individuals. Responders to the PolTY9 or PolLF10 epitope had a significantly lower plasma viral load (pVL) than nonresponders among HLA-B*15:02+ individuals, whereas no significant difference in pVL was found between responders to four other epitopes and nonresponders. The breadth of T cell responses to these two Pol epitopes correlated inversely with pVL. These findings suggest that HLA-B*15:02-restricted T cells specific for PolTY9 and PolLF10 contribute to the suppression of HIV-1 replication in HLA-B*15:02+ individuals. The HLA-B*15:02-associated mutation Pol266I reduced the recognition of PolTY9-specific T cells in vitro but did not affect HIV-1 replication by PolTY9-specific T cells in Pol266I mutant virus-infected individuals. These findings indicate that PolTY9-specific T cells suppress replication of the Pol266I mutant virus even though the T cells selected this mutant. This study demonstrates the effective role of T cells specific for these Pol epitopes to control circulating viruses in HIV-1 subtype A/E infection. IMPORTANCE It is expected that HIV-1-specific CD8+ T cells that effectively suppress HIV-1 replication will contribute to HIV-1 vaccine development and therapy to achieve an HIV cure. T cells specific for protective epitopes were identified in HIV-1 subtype B and C infections but not in subtype A/E infection, which is epidemic in Southeast Asia. In the present study, we identified six T cell epitopes derived from the subtype A/E virus and demonstrated that T cells specific for two Pol epitopes effectively suppressed HIV-1 replication in treatment-naive Vietnamese individuals infected with HIV-1 subtype A/E. One of these Pol protective epitopes was conserved among circulating viruses, and one escape mutation was accumulated in the other epitope. This mutation did not critically affect HIV-1 control by specific T cells in HIV-1 subtype A/E-infected individuals. This study identified two protective Pol epitopes and characterized them in cases of HIV-1 subtype A/E infection.
Assuntos
Linfócitos T CD8-Positivos , Epitopos de Linfócito T , Infecções por HIV , HIV-1 , Replicação Viral , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Antígenos HLA-B/imunologia , Humanos , Linfócitos T Citotóxicos/imunologia , Produtos do Gene pol do Vírus da Imunodeficiência Humana/imunologiaRESUMO
BACKGROUND: Attempts to achieve digital transformation across the health service have stimulated increasingly large-scale and more complex change programmes. These encompass a growing range of functions in multiple locations across the system and may take place over extended timeframes. This calls for new approaches to evaluate these programmes. MAIN BODY: Drawing on over a decade of conducting formative and summative evaluations of health information technologies, we here build on previous work detailing evaluation challenges and ways to tackle these. Important considerations include changing organisational, economic, political, vendor and markets necessitating tracing of evolving networks, relationships, and processes; exploring mechanisms of spread; and studying selected settings in depth to understand local tensions and priorities. CONCLUSIONS: Decision-makers need to recognise that formative evaluations, if built on solid theoretical and methodological foundations, can help to mitigate risks and help to ensure that programmes have maximum chances of success.
Assuntos
Difusão de Inovações , Informática Médica/organização & administração , Modelos Teóricos , Estudos de Avaliação como Assunto , HumanosRESUMO
Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (n = 208) to Aedes aegypti mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1-4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission.
Assuntos
Aedes/virologia , Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/transmissão , Dengue/virologia , Insetos Vetores/virologia , Animais , Sequência de Bases , Estudos de Coortes , Vírus da Dengue/classificação , Ensaio de Imunoadsorção Enzimática , Interações Hospedeiro-Patógeno , Humanos , Funções Verossimilhança , Modelos Genéticos , Dados de Sequência Molecular , Filogenia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Sorotipagem , Vietnã/epidemiologia , Viremia/epidemiologiaRESUMO
Although previous studies have reported HIV-1-specific T cell responses in HIV-1-exposed seronegative (HESN) individuals, there has been no detailed analysis of these T cells against HIV-1 infection. We investigated HIV-1-specific CD8+ T cell responses in 200 Japanese HESN men who have sex with men (MSM). T cell responses to 143 well-characterized HIV-1 epitope peptides were analyzed by intracellular cytokine staining assay consisting of 3-week cultures of PBMCs stimulated with peptides. HLA-B∗51:01-restricted Pol TI8-specific and HLA-A∗02:06-restricted Pol SV9-specific CD8+ T cells were identified in two and one individuals, respectively, whereas CD8+ T cells specific for other HLA-A∗02:06-restricted or HLA-B∗51:01 epitopes were not present in these individuals. These epitope-specific T cells recognized HIV-1-infected cells. Because these two epitopes were previously reported to be protective in HIV-1-infected individuals, these protective epitope-specific T cells might suppress HIV-1 replication in HESN-MSM individuals. The present study suggests the contribution of protective epitope-specific T cells to protection against HIV-1 infection.
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Long-term memory T cells have not been well analyzed in individuals vaccinated with a COVID-19 vaccine although analysis of these T cells is necessary to evaluate vaccine efficacy. Here, investigate HLA-A*24:02-restricted CD8+ T cells specific for SARS-CoV-2-derived spike (S) epitopes in individuals immunized with the BNT162b2 mRNA vaccine. T cells specific for the S-QI9 and S-NF9 immunodominant epitopes have higher ability to recognize epitopes than other epitope-specific T cell populations. This higher recognition of S-QI9-specific T cells is due to the high stability of the S-QI9 peptide for HLA-A*24:02, whereas that of S-NF9-specific T cells results from the high affinity of T cell receptor. T cells specific for S-QI9 and S-NF9 are detectable >30 weeks after the second vaccination, indicating that the vaccine induces long-term memory T cells specific for these epitopes. Because the S-QI9 epitope is highly conserved among SARS-CoV-2 variants, S-QI9-specific T cells may help prevent infection with SARS-CoV-2 variants.
Assuntos
COVID-19 , SARS-CoV-2 , Vacina BNT162 , Linfócitos T CD8-Positivos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Epitopos de Linfócito T , Humanos , Memória de Longo Prazo , Glicoproteína da Espícula de Coronavírus , Vacinas Sintéticas , Vacinas de mRNARESUMO
BACKGROUND: The Global Digital Exemplar (GDE) Programme is a national initiative to promote digitally enabled transformation in English provider organizations. The Programme applied benefits realization management techniques to promote and demonstrate transformative outcomes. This work was part of an independent national evaluation of the GDE Programme. AIMS: We explored how benefits realization management was approached and conceptualized in the GDE Programme. METHODS: We conducted a series of 36 longitudinal case studies of provider organizations participating in the GDE Programme, 12 of which were in depth. Data collection included a combination of 628 interviews (with implementation staff in provider organizations, national programme management staff, and suppliers), 499 documents (of national and local implementation plans and lessons learned), and 190 nonparticipant observations (of national and local programme management meetings to develop insights into the broader context of benefits realization activities, tensions arising, and how these were negotiated). Data were coded drawing on a sociotechnical framework developed in related work and thematically analyzed, initially within and then across cases, with the help of NVivo 11 software. RESULTS: Most stakeholders broadly agreed with the rationale of benefits realization in the GDE Programme to show due diligence that public money was appropriately spent, and to develop an evidence base supporting the value of digitally enabled transformation. Differing national and local reporting purposes, however, created tensions. Central requirements, for progress reporting and tracking high-level benefits, had limited perceived local value and were seen to impose an unnecessary burden on provider organizations. This was accentuated by the lack of harmonization of reporting requirements to different stakeholders (which differed in content and timing). There were tensions between the desire for early evidence of outcomes and the slow processes of infrastructural change (which created problems of attribution of benefits to causes as benefits emerged gradually and over long timeframes), and also between reporting immediately visible local changes and showing how these flowed through to high level organization wide benefits (eg, in terms of health outcomes or cost savings/return on investment). The attempt to fulfill these diverging agendas and informational needs within a single reporting tool had limited success. These difficulties were mitigated by efforts to simplify reporting requirements and to support targeted collection of key national outcome measures. Although progress was hampered by an initial lack of benefits realization expertise in provider organizations, some providers subsequently retained these skills for their own change management purposes. CONCLUSIONS: There is a need to recognize the limitations and cost of benefits realization management practices in the context of healthcare digitalization where benefits may materialize over long timeframes and in unanticipated ways. Although diverse stakeholder information needs may create tensions, prior agreement about rationales for collecting information and a targeted approach to tracking local and high-level benefits may enhance local relevance, reduce perceived reporting burdens, and improve acceptance/effectiveness. A single integrated reporting mechanism is unlikely to fulfill both national and local requirements.
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Atenção à Saúde , Instalações de Saúde , Humanos , Estudos LongitudinaisRESUMO
OBJECTIVE: To assess the number and characteristics of potentially harmful incidents occurring during placement of medical students in remote Aboriginal communities in the Northern Territory. DESIGN, PARTICIPANTS AND SETTING: A retrospective audit of medical students' files from Northern Territory General Practice Education placements in Central Australia for the period from January 2006 to December 2007. MAIN OUTCOME MEASURES: Number and type of potentially harmful incidents. RESULTS: A total of 163 placements were undertaken. Of these, 98 (60%) had adequate documentation to determine whether an incident had occurred. There were 28 cases (17%) where potentially harmful incidents were judged to have occurred. Most incidents fell under several descriptive categories, but clinical supervision, professional practice and administrative issues were most common. CONCLUSIONS: One in six students experienced a potentially harmful incident during remote area placement in 2006-2007. While acknowledging the exploratory nature of this investigation and the major educational benefits that clearly arise from these placements, our findings indicate problems with clinical supervision and administration.
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Educação de Graduação em Medicina , Relações Interpessoais , Havaiano Nativo ou Outro Ilhéu do Pacífico , Qualidade da Assistência à Saúde , Serviços de Saúde Rural/normas , População Rural , Faculdades de Medicina , Estudantes de Medicina/psicologia , Adulto , Educação a Distância , Feminino , Medicina Geral/educação , Humanos , Masculino , Northern Territory , Adulto JovemRESUMO
OBJECTIVE: The Global Digital Exemplar (GDE) Program is a national attempt to accelerate digital maturity in healthcare providers through promoting knowledge transfer across the English National Health Service (NHS). "Blueprints"-documents capturing implementation experience-were intended to facilitate this knowledge transfer. Here we explore how Blueprints have been conceptualized, produced, and used to promote interorganizational knowledge transfer across the NHS. MATERIALS AND METHODS: We undertook an independent national qualitative evaluation of the GDE Program. This involved collecting data using semistructured interviews with implementation staff and clinical leaders in provider organizations, nonparticipant observation of meetings, and key documents. We also attended a range of national meetings and conferences, interviewed national program managers, and analyzed a range of policy documents. Our analysis drew on sociotechnical principles, combining deductive and inductive methods. RESULTS: Data comprised 508 interviews, 163 observed meetings, and analysis of 325 documents. We found little evidence of Blueprints being adopted in the manner originally conceived by national program managers. However, they proved effective in different ways to those planned. As well as providing a helpful initial guide to a topic, we found that Blueprints served as a method of identifying relevant expertise that paved the way for subsequent discussions and richer knowledge transfers amongst provider organizations. The primary value of Blueprinting, therefore, seemed to be its role as a networking tool. Members of different organizations came together in developing, applying, and sustaining Blueprints through bilateral conversations-in some circumstances also fostering informal communities of practice. CONCLUSIONS: Blueprints may be effective in facilitating knowledge transfer among healthcare organizations, but need to be accompanied by other evolving methods, such as site visits and other networking activities, to iteratively transfer knowledge and experience.
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Hospitais , Medicina Estatal , Comunicação , Pessoal de Saúde , HumanosRESUMO
Fused isopropylfuran and dimethylpyran units are privileged structures present in numerous bioactive natural products exemplified, in the field of anticancer drugs, by the furanoxanthone psorospermin and the pyranoacridone acronycine. Psorospermin binds to the N-7 position of the guanine units in the presence of topoisomerase II. In contrast, acronycine derivatives such as cis-1,2-diacetoxy-1,2-dihydrobenzo[b]acronycine alkylate the 2-amino group of DNA guanine residues in the minor groove. Hybrid compounds associating the acridone or benzo[b]acridone chromophore of acronycine derivatives and the epoxyfuran alkylating unit present in psorospermin also display very potent antiproliferative activities, alkylating DNA guanine units at position N-7 in the major groove, as natural xanthones belonging to the psorospermin series.
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Acronina/farmacologia , Produtos Biológicos/farmacologia , Dano ao DNA , Xantonas/farmacologia , Acronina/química , Produtos Biológicos/química , Estrutura Molecular , Xantonas/químicaRESUMO
BACKGROUND: The terms 'cultural safety' and 'cultural competence' are used widely in indigenous and culturally and linguistically diverse health contexts. They form the basis for effective patient centred care and the professional advocacy role of the general practitioner. OBJECTIVE: This article discusses the concepts of cultural safety and cultural competence. A checklist of cultural competency practice is also provided for health practitioners. DISCUSSION: Cultural safety is the experience of the recipient of care. It is comparable to clinical safety, allowing the patient to feel safe in health care interactions and be involved in changes to health services. It has been suggested that cultural safety training may be one mechanism to reduce disparities in indigenous health status. Cultural competence is a broader term that focuses on the capacity of the health system to improve health and wellbeing by integrating culture into the delivery of health services.
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Competência Cultural , Serviços de Saúde do Indígena/organização & administração , Havaiano Nativo ou Outro Ilhéu do Pacífico , Assistência Centrada no Paciente/organização & administração , Austrália , Diversidade Cultural , HumanosRESUMO
BACKGROUND: Educating the health workforce in indigenous health has been set as a high priority by educational bodies and providers of general practice training. These groups advise the involvement of local indigenous communities in medical teaching and training. Few have asked community members what issues are important to them when teaching health professionals. OBJECTIVE: This article discusses the outcomes of focus groups and interviews of indigenous community members regarding the engagement in education activities, barriers to participation, and supports required for ongoing participation. DISCUSSION: Results reveal insights into indigenous community members' perceptions, understanding of, and participation in, cross cultural teaching. Cross cultural interactions can be both rewarding and a risk to the teaching process. This needs to be managed and facilitated appropriately and in a timely manner.