RESUMEN
The interactions between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and human host factors enable the virus to propagate infections that lead to Coronavirus Disease 2019 (COVID-19). The spike protein is the largest structural component of the virus and mediates interactions essential for infection, including with the primary angiotensin-converting enzyme 2 (ACE2) receptor. We performed two independent cell-based systematic screens to determine whether there are additional proteins by which the spike protein of SARS-CoV-2 can interact with human cells. We discovered that in addition to ACE2, expression of LRRC15 also causes spike protein binding. This interaction is distinct from other known spike attachment mechanisms such as heparan sulfates or lectin receptors. Measurements of orthologous coronavirus spike proteins implied the interaction was functionally restricted to SARS-CoV-2 by accessibility. We localized the interaction to the C-terminus of the S1 domain and showed that LRRC15 shares recognition of the ACE2 receptor binding domain. From analyzing proteomics and single-cell transcriptomics, we identify LRRC15 expression as being common in human lung vasculature cells and fibroblasts. Levels of LRRC15 were greatly elevated by inflammatory signals in the lungs of COVID-19 patients. Although infection assays demonstrated that LRRC15 alone is not sufficient to permit viral entry, we present evidence that it can modulate infection of human cells. This unexpected interaction merits further investigation to determine how SARS-CoV-2 exploits host LRRC15 and whether it could account for any of the distinctive features of COVID-19.
Asunto(s)
COVID-19 , Humanos , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo , Enzima Convertidora de Angiotensina 2/metabolismo , Unión Proteica , Proteínas de la Membrana/metabolismoRESUMEN
BACKGROUND: Methods for evaluating efficacy of core malaria interventions in experimental and operational settings are well established but gaps exist for spatial repellents (SR). The objective of this study was to compare three different techniques: (1) collection of blood-fed mosquitoes (feeding), (2) human landing catch (HLC), and (3) CDC light trap (CDC-LT) collections for measuring the indoor protective efficacy (PE) of the volatile pyrethroid SR product Mosquito Shield™ METHODS: The PE of Mosquito Shield™ against a wild population of pyrethroid-resistant Anopheles arabiensis mosquitoes was determined via feeding, HLC, or CDC-LT using four simultaneous 3 by 3 Latin squares (LS) run using 12 experimental huts in Tanzania. On any given night each technique was assigned to two huts with control and two huts with treatment. The LS were run twice over 18 nights to give a sample size of 72 replicates for each technique. Data were analysed by negative binomial regression. RESULTS: The PE of Mosquito Shield™ measured as feeding inhibition was 84% (95% confidence interval (CI) 58-94% [Incidence Rate Ratio (IRR) 0.16 (0.06-0.42), p < 0.001]; landing inhibition 77% [64-86%, (IRR 0.23 (0.14-0.36) p < 0.001]; and reduction in numbers collected by CDC-LT 30% (0-56%) [IRR 0.70 (0.44-1.0) p = 0.160]. Analysis of the agreement of the PE measured by each technique relative to HLC indicated no statistical difference in PE measured by feeding inhibition and landing inhibition [IRR 0.73 (0.25-2.12) p = 0.568], but a significant difference in PE measured by CDC-LT and landing inhibition [IRR 3.13 (1.57-6.26) p = 0.001]. CONCLUSION: HLC gave a similar estimate of PE of Mosquito Shield™ against An. arabiensis mosquitoes when compared to measuring blood-feeding directly, while CDC-LT underestimated PE relative to the other techniques. The results of this study indicate that CDC-LT could not effectively estimate PE of the indoor spatial repellent in this setting. It is critical to first evaluate the use of CDC-LT (and other tools) in local settings prior to their use in entomological studies when evaluating the impact of indoor SR to ensure that they reflect the true PE of the intervention.
Asunto(s)
Anopheles , Repelentes de Insectos , Malaria , Animales , Estados Unidos , Humanos , Anopheles/fisiología , Tanzanía , Repelentes de Insectos/farmacología , Malaria/prevención & control , Centers for Disease Control and Prevention, U.S. , Control de Mosquitos/métodos , Mosquitos VectoresRESUMEN
BACKGROUND: Spatial repellents that create airborne concentrations of an active ingredient (AI) within a space offer a scalable solution to further reduce transmission of malaria, by disrupting mosquito behaviours in ways that ultimately lead to reduced human-vector contact. Passive emanator spatial repellents can protect multiple people within the treated space and can last for multiple weeks without the need for daily user touchpoints, making them less intrusive interventions. They may be particularly advantageous in certain use cases where implementation of core tools may be constrained, such as in humanitarian emergencies and among mobile at-risk populations. The purpose of this study was to assess the efficacy of Mosquito Shield™ deployed in experimental huts against wild, free-flying, pyrethroid-resistant Anopheles arabiensis mosquitoes in Tanzania over 1 month. METHODS: The efficacy of Mosquito Shield™ transfluthrin spatial repellent in reducing mosquito lands and blood-feeding was evaluated using 24 huts: sixteen huts were allocated to Human Landing Catch (HLC) collections and eight huts to estimating blood-feeding. In both experiments, half of the huts received no intervention (control) while the remaining received the intervention randomly allocated to huts and remained fixed for the study duration. Outcomes measured were mosquito landings, blood-fed, resting and dead mosquitoes. Data were analysed by multilevel mixed effects regression with appropriate dispersion and link function accounting for volunteer, hut and day. RESULTS: Landing inhibition was estimated to be 70% (57-78%) [IRR 0.30 (95% CI 0.22-0.43); p < 0.0001] and blood-feeding inhibition was estimated to be 69% (56-79%) [IRR 0.31 (95% CI 0.21-0.44; p < 0.0001] There was no difference in the protective efficacy estimates of landing and blood-feeding inhibition [IRR 0.98 (95% CI 0.53-1.82; p = 0.958]. CONCLUSIONS: This study demonstrated that Mosquito Shield™ was efficacious against a wild pyrethroid-resistant strain of An. arabiensis mosquitoes in Tanzania for up to 1 month and could be used as a complementary or stand-alone tool where gaps in protection offered by core malaria vector control tools exist. HLC is a suitable technique for estimating bite reductions conferred by spatial repellents especially where direct blood-feeding measurements are not practical or are ethically limited.
Asunto(s)
Anopheles , Repelentes de Insectos , Malaria , Animales , Humanos , Tanzanía , Malaria/prevención & control , Mosquitos Vectores , Repelentes de Insectos/farmacologíaRESUMEN
In this article, we derive and compare methods to derive P-values and sets of confidence intervals with strong control of the family-wise error rates and coverage for estimates of treatment effects in cluster randomized trials with multiple outcomes. There are few methods for P-value corrections and deriving confidence intervals, limiting their application in this setting. We discuss the methods of Bonferroni, Holm, and Romano and Wolf and adapt them to cluster randomized trial inference using permutation-based methods with different test statistics. We develop a novel search procedure for confidence set limits using permutation tests to produce a set of confidence intervals under each method of correction. We conduct a simulation-based study to compare family-wise error rates, coverage of confidence sets, and the efficiency of each procedure in comparison to no correction using both model-based standard errors and permutation tests. We show that the Romano-Wolf type procedure has nominal error rates and coverage under non-independent correlation structures and is more efficient than the other methods in a simulation-based study. We also compare results from the analysis of a real-world trial.
Asunto(s)
Intervalos de Confianza , Ensayos Clínicos Controlados Aleatorios como Asunto , Simulación por Computador , Análisis por ConglomeradosRESUMEN
OBJECTIVE: We systematically reviewed all studies published between 2000 and June 2021 that estimated under 5 diarrhoea rates in low- and middle-income countries and extracted data on diarrhoea rates, measurement methods and reactivity. METHODS: We summarised data from studies that performed direct comparisons of methods, and indirectly compared studies which utilised only one method using meta-regression to determine the association between methods and estimated diarrhoea rates. RESULTS: In total, 288 studies met our inclusion criteria: 4 direct comparisons and 284 studies utilising only one measurement method. Meta-regression across all studies showed that diarrhoea rates were sensitive to method of measurement. We estimated that passive surveillance methods were associated with a 97% lower estimated rate than active surveillance (IRR = 0.03, 95% CI [0.02, 0.06]). Among active surveillance studies, a doubling of recall period was associated with a 48% lower rate (IRR = 0.52 [0.46, 0.60]), while decreased questioning frequency was associated with a higher estimated rate: at the extreme, one time questioning yielded an over 4× higher rate than daily questioning (IRR = 4.22 [2.73, 6.52]). CONCLUSIONS: Estimated diarrhoea rates are sensitive to their measurement methods. There is a need for a standardisation of diarrhoea measurement methods, and for the use of other outcomes in the measurement of population-level gastrointestinal health.
Asunto(s)
Países en Desarrollo , Diarrea , Diarrea/epidemiología , HumanosRESUMEN
RATIONALE: Preclinical testing of cardiotoxicity and efficacy of novel heart failure therapies faces a major limitation: the lack of an in situ culture system that emulates the complexity of human heart tissue and maintains viability and functionality for a prolonged time. OBJECTIVE: To develop a reliable, easily reproducible, medium-throughput method to culture pig and human heart slices under physiological conditions for a prolonged period of time. METHODS AND RESULTS: Here, we describe a novel, medium-throughput biomimetic culture system that maintains viability and functionality of human and pig heart slices (300 µm thickness) for 6 days in culture. We optimized the medium and culture conditions with continuous electrical stimulation at 1.2 Hz and oxygenation of the medium. Functional viability of these slices over 6 days was confirmed by assessing their calcium homeostasis, twitch force generation, and response to ß-adrenergic stimulation. Temporal transcriptome analysis using RNAseq at day 2, 6, and 10 in culture confirmed overall maintenance of normal gene expression for up to 6 days, while over 500 transcripts were differentially regulated after 10 days. Electron microscopy demonstrated intact mitochondria and Z-disc ultra-structures after 6 days in culture under our optimized conditions. This biomimetic culture system was successful in keeping human heart slices completely viable and functionally and structurally intact for 6 days in culture. We also used this system to demonstrate the effects of a novel gene therapy approach in human heart slices. Furthermore, this culture system enabled the assessment of contraction and relaxation kinetics on isolated single myofibrils from heart slices after culture. CONCLUSIONS: We have developed and optimized a reliable medium-throughput culture system for pig and human heart slices as a platform for testing the efficacy of novel heart failure therapeutics and reliable testing of cardiotoxicity in a 3-dimensional heart model.
Asunto(s)
Biomimética/métodos , Ventrículos Cardíacos/ultraestructura , Función Ventricular/fisiología , Adulto , Animales , Femenino , Corazón/fisiología , Ventrículos Cardíacos/citología , Humanos , Masculino , Metabolómica/métodos , Persona de Mediana Edad , Miocardio/citología , Miocardio/ultraestructura , Técnicas de Cultivo de Órganos/métodos , Porcinos , Transcriptoma/fisiologíaRESUMEN
In this article, we review and evaluate a number of methods used in the design and analysis of small three-arm parallel cluster randomized trials. We conduct a simulation-based study to evaluate restricted randomization methods including covariate-constrained randomization and a novel method for matched-group cluster randomization. We also evaluate the appropriate modelling of the data and small sample inferential methods for a variety of treatment effects relevant to three-arm trials. Our results indicate that small-sample corrections are required for high (0.05) but not low (0.001) values of the intraclass correlation coefficient and their performance can depend on trial design, number of clusters, and the nature of the hypothesis being tested. The Satterthwaite correction generally performed best at an ICC of 0.05 with a nominal type I error rate for single-period trials, and in trials with repeated measures type I error rates were between 0.04 and 0.06. Restricted randomization methods produce little benefit in trials with repeated measures but in trials with single post-intervention design can provide relatively large gains in power when compared to the most unbalanced possible allocations. Matched-group randomization improves power but is not as effective as covariate-constrained randomization. For model-based analysis, adjusting for fewer covariates than were used in a restricted randomization process under any design can produce non-nominal type I error rates and reductions in power. Where comparisons to two-arm cluster trials are possible, the performance of the methods is qualitatively very similar.
Asunto(s)
Proyectos de Investigación , Análisis por Conglomerados , Simulación por Computador , Humanos , Distribución Aleatoria , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
BACKGROUND: People affected by leprosy are at increased risk of ulcers from peripheral nerve damage. This in turn can lead to visible impairments, stigmatisation and economic marginalisation. Health care providers suggest that patients should be empowered to self-manage their condition to improve outcomes and reduce reliance on services. Self-care involves carrying out personal care tasks with the aim of preventing disabilities or preventing further deterioration. Self-help, on the other hand, addresses the wider psychological, social and economic implications of leprosy and incorporates, for example, skills training and microfinance schemes. The aim of this study, known as SHERPA (Self-Help Evaluation for lepRosy and other conditions in NePAl) is to evaluate a service intervention called Integrated Mobilization of People for Active Community Transformation (IMPACT) designed to encourage both self-care and self-help in marginalised people including those affected by leprosy. METHODS: A mixed-method evaluation study in Province 5, Nepal comprising two parts. First, a prospective, cluster-based, non-randomised controlled study to evaluate the effectiveness of self-help groups on ulcer metrics (people affected by leprosy only) and on four generic outcome measures (all participants) - generic health status, wellbeing, social integration and household economic performance. Second, a qualitative study to examine the implementation and fidelity of the intervention. IMPACT: This research will provide information on the effectiveness of combined self-help and self-care groups, on quality of life, social integration and economic wellbeing for people living with leprosy, disability or who are socially and economically marginalised in low- and middle- income countries.
Asunto(s)
Lepra , Calidad de Vida , Análisis por Conglomerados , Estudios de Cohortes , Humanos , Lepra/terapia , Nepal , Estudios Prospectivos , AutoeficaciaRESUMEN
BACKGROUND: Improving the quality of primary healthcare provision is a key goal in low-and middle-income countries (LMICs). However, to develop effective quality improvement interventions, we first need to be able to accurately measure the quality of care. The methods most commonly used to measure the technical quality of care all have some key limitations in LMICs settings. Video-observation is appealing but has not yet been used in this context. We examine preliminary feasibility and acceptability of video-observation for assessing physician quality in a hospital outpatients' department in Nigeria. We also develop measurement procedures and examine measurement characteristics. METHODS: Cross-sectional study at a large tertiary care hospital in Ibadan, Nigeria. Consecutive physician-patient consultations with adults and children under five seeking outpatient care were video-recorded. We also conducted brief interviews with participating physicians to gain feedback on our approach. Video-recordings were double-coded by two medically trained researchers, independent of the study team and each other, using an explicit checklist of key processes of care that we developed, from which we derived a process quality score. We also elicited a global quality rating from reviewers. RESULTS: We analysed 142 physician-patient consultations. The median process score given by both coders was 100 %. The modal overall rating category was 'above standard' (or 4 on a scale of 1-5). Coders agreed on which rating to assign only 44 % of the time (weighted Cohen's kappa = 0.26). We found in three-level hierarchical modelling that the majority of variance in process scores was explained by coder disagreement. A very high correlation of 0.90 was found between the global quality rating and process quality score across all encounters. Participating physicians liked our approach, despite initial reservations about being observed. CONCLUSIONS: Video-observation is feasible and acceptable in this setting, and the quality of consultations was high. However, we found that rater agreement is low but comparable to other modalities that involve expert clinician judgements about quality of care including in-person direct observation and case note review. We suggest ways to improve scoring consistency including careful rater selection and improved design of the measurement procedure for the process score.
Asunto(s)
Médicos , Habilidades Sociales , Adulto , Niño , Estudios Transversales , Humanos , Nigeria , Servicio Ambulatorio en HospitalRESUMEN
BACKGROUND: Text messaging systems are used to collect data on symptom prevalence. Using a text messaging system, we evaluated the effects of question load, question frequency, and financial incentive on response rates and reported infant diarrhoea rates in an infant diarrhoea survey. METHODS: We performed a factorial cross-over randomised controlled trial of an SMS surveying system for infant diarrhoea surveillance with treatments: financial incentive (yes/no), question load (1-question/3-question), and questioning frequency (daily/fortnightly). Participants progressed through all treatment combinations over eight two-week rounds. Data were analysed using multivariable logistic regressions to determine the impacts of the treatments on the response rates and reported diarrhoea rates. Attitudes were explored through qualitative interviews. RESULTS: For the 141 participants, the mean response rate was 47%. In terms of percentage point differences (ppd), daily questioning was associated with a lower response rate than fortnightly (- 1·2[95%CI:-4·9,2·5]); high (3-question) question loads were associated with a lower response rate than low (1-question) question loads (- 7·0[95%CI:- 10·8,-3·1]); and financial incentivisation was associated with a higher response rate than no financial incentivisation (6·4[95%CI:2·6,10·2]). The mean two-week diarrhoea rate was 36·4%. Daily questioning was associated with a higher reported diarrhoea rate than fortnightly (29·9[95%CI:22·8,36·9]); with little evidence for impact by incentivisation or question load. CONCLUSIONS: Close to half of all participants responded to the SMS survey. Daily questioning evoked a statistically higher rate of reported diarrhoea, while financial incentivisation and low (1-question) question loads evoked higher response rates than no incentive and high (3-question) question loads respectively. TRIAL REGISTRATION: The protocol was prospectively registered on ISRCTN on the 20th of March 2019 under number ISRCTN11410773 .
Asunto(s)
Envío de Mensajes de Texto , Estudios Cruzados , Diarrea/diagnóstico , Diarrea/epidemiología , Humanos , Lactante , Encuestas y CuestionariosRESUMEN
The optimal antithrombotic therapy for patients undergoing TAVI with concomitant indication for oral anticoagulation remains unclear. In this high-risk population group, there is a paucity of data with regards to the use of DOACs. In the present study we compared long-term clinical outcomes of TAVI patients requiring anticoagulation, treated with warfarin versus DOACs. Consecutive patients, who underwent TAVI with indication for oral anticoagulation from the multicenter ATLAS registry were studied and divided in two groups depending on the chosen anticoagulation regimen, warfarin vs. DOACs. 30-day survival, as well as estimated 1 and 2-year all-cause mortality were compared between groups. The secondary endpoint included in-hospital major or life-threatening bleeding. The study group included 217 patients (102 treated with warfarin; 115 treated with DOACs). Kaplan-Meier estimated survival was found to be statistically similar in the warfarin and DOAC groups (90.6% vs. 93.7% for 1-year and 84.5% vs. 88.5%, for 2-year survival, respectively, Plog-rank = 0.984). Adjusted hazard ratio for all cause mortality was similar between the two groups (HRwarfarin vs. DOAC = 1.15; 95% CI 0.33 to 4.04, p = 0.829). Propensity matching revealed similar results. At 30-days, all-cause mortality was found to be comparable between the two groups. With regards to BARC defined bleeding complications, major and life-threatening complications did not differ between the two anticoagulation groups (6% vs. 8% for warfarin and DOACs respectively, p = 0.857). DOACs seem to demonstrate a similar safety and efficacy profile compared to warfarin in TAVI patients with a concomitant indication for oral anticoagulation.
Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Inhibidores del Factor Xa , Hemorragia , Efectos Adversos a Largo Plazo , Complicaciones Posoperatorias , Trombosis , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Warfarina , Anciano de 80 o más Años , Anticoagulantes/administración & dosificación , Anticoagulantes/efectos adversos , Coagulación Sanguínea/efectos de los fármacos , Inhibidores del Factor Xa/administración & dosificación , Inhibidores del Factor Xa/efectos adversos , Femenino , Hemorragia/inducido químicamente , Hemorragia/diagnóstico , Hemorragia/prevención & control , Humanos , Efectos Adversos a Largo Plazo/diagnóstico , Efectos Adversos a Largo Plazo/etiología , Efectos Adversos a Largo Plazo/mortalidad , Masculino , Selección de Paciente , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/prevención & control , Pronóstico , Sistema de Registros/estadística & datos numéricos , Análisis de Supervivencia , Trombosis/sangre , Trombosis/etiología , Trombosis/mortalidad , Trombosis/prevención & control , Reemplazo de la Válvula Aórtica Transcatéter/métodos , Warfarina/administración & dosificación , Warfarina/efectos adversosRESUMEN
BACKGROUND: By 2015, Malawi had not achieved Millennium Development Goal 4, reducing maternal mortality by about 35% from 675 to 439 deaths per 100,000 livebirths. Hypothesised reasons included low uptake of antenatal care (ANC), intrapartum care, and postnatal care. Involving community health workers (CHWs) in identification of pregnant women and linking them to perinatal services is a key strategy to reinforce uptake of perinatal care in Neno, Malawi. We evaluated changes in uptake after deployment of CHWs between March 2014 and June 2016. METHODS: A CHW intervention was implemented in Neno District, Malawi in a designated catchment area of about 3100 women of childbearing age. The pre-intervention period was March 2014 to February 2015, and the post-intervention period was March 2015 to June 2016. A 5-day maternal health training package was delivered to 211 paid and supervised CHWs. CHWs were deployed to identify pregnant women and escort them to perinatal care visits. A synthetic control method, in which a "counterfactual site" was created from six available control facilities in Neno District, was used to evaluate the intervention. Outcomes of interest included uptake of first-time ANC, ANC within the first trimester, four or more ANC visits, intrapartum care, and postnatal care follow-up. RESULTS: Women enrolled in ANC increased by 18% (95% Credible Interval (CrI): 8, 29%) from an average of 83 to 98 per month, the proportion of pregnant women starting ANC in the first trimester increased by 200% (95% CrI: 162, 234%) from 10 to 29% per month, the proportion of women completing four or more ANC visits increased by 37% (95% CrI: 31, 43%) from 28 to 39%, and monthly utilisation of intrapartum care increased by 20% (95% CrI: 13, 28%) from 85 to 102 women per month. There was little evidence that the CHW intervention changed utilisation of postnatal care (- 37, 95% CrI: - 224, 170%). CONCLUSIONS: In a rural district in Malawi, uptake of ANC and intrapartum care increased considerably following an intervention using CHWs to identify pregnant women and link them to care.
Asunto(s)
Agentes Comunitarios de Salud/organización & administración , Aceptación de la Atención de Salud/estadística & datos numéricos , Atención Perinatal/estadística & datos numéricos , Mujeres Embarazadas , Evaluación de Programas y Proyectos de Salud , Adulto , Femenino , Humanos , Recién Nacido , Malaui , Masculino , Servicios de Salud Materna/estadística & datos numéricos , Persona de Mediana Edad , Atención Perinatal/organización & administración , Embarazo , Población RuralRESUMEN
In a recent issue of Journal of Medical Ethics (JME), we discussed the ethical review of evaluations of interventions that would occur whether or not the evaluation was taking place. We concluded that standard research ethics frameworks including the Ottawa Statement, which requires justification for all aspects of an intervention and its roll-out, were a poor guide in this area. We proposed that a consideration of researcher responsibility, based on the consequences of the research taking place, would be a more appropriate way delineate the scope of research ethics review. Weijer and Taljaard present a counterargument to our proposal, which we address in this reply. They claim that a focus on researcher responsibility will weaken the protection of research participants and link it to 'unethical research' and a 'government experimenting on its own people'. However, the moral responsibility of researchers is defined in terms of the consequences of the research on human welfare and harm, not in opposition to it. Weijer and Taljaard argue that researchers must justify what they are studying whether or not they have any control over it and that governments must justify their programmes, including by demonstrating equipoise, to a research ethics committee if they implement them in a randomised way. We strongly disagree that this is a defensible way to define the scope of research ethics review and argue that this provides no further protections to research participants beyond what we propose, but places a potential barrier to learning from government programmes.
Asunto(s)
Comités de Ética en Investigación , Ética en Investigación , Revisión Ética , Gobierno , Humanos , Estándares de ReferenciaRESUMEN
Public health and service delivery programmes, interventions and policies (collectively, 'programmes') are typically developed and implemented for the primary purpose of effecting change rather than generating knowledge. Nonetheless, evaluations of these programmes may produce valuable learning that helps determine effectiveness and costs as well as informing design and implementation of future programmes. Such studies might be termed 'opportunistic evaluations', since they are responsive to emergent opportunities rather than being studies of interventions that are initiated or designed by researchers. However, current ethical guidance and registration procedures make little allowance for scenarios where researchers have played no role in the development or implementation of a programme, but nevertheless plan to conduct a prospective evaluation. We explore the limitations of the guidance and procedures with respect to opportunistic evaluations, providing a number of examples. We propose that one key missing distinction in current guidance is moral responsibility: researchers can only be held accountable for those aspects of a study over which they have control. We argue that requiring researchers to justify an intervention, programme or policy that would occur regardless of their involvement prevents or hinders research in the public interest without providing any further protections to research participants. We recommend that trial consent and ethics procedures allow for a clear separation of responsibilities for the intervention and the evaluation.
Asunto(s)
Investigación sobre Servicios de Salud/ética , Obligaciones Morales , Investigación en Sistemas de Salud Pública/ética , Salud Pública/ética , Investigadores/ética , Comités de Ética en Investigación , Ética en Investigación , Humanos , Evaluación de Programas y Proyectos de Salud , Proyectos de InvestigaciónRESUMEN
Myocardial slices, also known as "cardiac tissue slices" or "organotypic heart slices," are ultrathin (100-400 µm) slices of living adult ventricular myocardium prepared using a high-precision vibratome. They are a model of intermediate complexity as they retain the native multicellularity, architecture, and physiology of the heart, while their thinness ensures adequate oxygen and metabolic substrate diffusion in vitro. Myocardial slices can be produced from a variety of animal models and human biopsies, thus providing a representative human in vitro platform for translational cardiovascular research. In this review, we compare myocardial slices to other in vitro models and highlight some of the unique advantages provided by this platform. Additionally, we discuss the work performed in our laboratory to optimize myocardial slice preparation methodology, which resulted in highly viable myocardial slices from both large and small mammalian hearts with only 2-3% cardiomyocyte damage and preserved structure and function. Applications of myocardial slices span both basic and translational cardiovascular science. Our laboratory has utilized myocardial slices for the investigation of cardiac multicellularity, visualizing 3D collagen distribution and micro/macrovascular networks using tissue clearing protocols and investigating the effects of novel conductive biomaterials on cardiac physiology. Myocardial slices have been widely used for pharmacological testing. Finally, the current challenges and future directions for the technology are discussed.
Asunto(s)
Técnicas In Vitro , Microtomía , Miocardio , Miocitos Cardíacos , Investigación Biomédica Traslacional/métodos , Animales , Comunicación Celular , Supervivencia Celular , Humanos , Miocardio/metabolismo , Miocardio/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Supervivencia TisularRESUMEN
In the first paper in this Series we assessed theoretical and empirical evidence and concluded that the health of people living in slums is a function not only of poverty but of intimately shared physical and social environments. In this paper we extend the theory of so-called neighbourhood effects. Slums offer high returns on investment because beneficial effects are shared across many people in densely populated neighbourhoods. Neighbourhood effects also help explain how and why the benefits of interventions vary between slum and non-slum spaces and between slums. We build on this spatial concept of slums to argue that, in all low-income and-middle-income countries, census tracts should henceforth be designated slum or non-slum both to inform local policy and as the basis for research surveys that build on censuses. We argue that slum health should be promoted as a topic of enquiry alongside poverty and health.
Asunto(s)
Política de Salud , Áreas de Pobreza , Características de la Residencia , Humanos , Factores SocioeconómicosRESUMEN
Massive slums have become major features of cities in many low-income and middle-income countries. Here, in the first in a Series of two papers, we discuss why slums are unhealthy places with especially high risks of infection and injury. We show that children are especially vulnerable, and that the combination of malnutrition and recurrent diarrhoea leads to stunted growth and longer-term effects on cognitive development. We find that the scientific literature on slum health is underdeveloped in comparison to urban health, and poverty and health. This shortcoming is important because health is affected by factors arising from the shared physical and social environment, which have effects beyond those of poverty alone. In the second paper we will consider what can be done to improve health and make recommendations for the development of slum health as a field of study.
Asunto(s)
Disparidades en el Estado de Salud , Áreas de Pobreza , Humanos , Factores SocioeconómicosRESUMEN
The chloroplast houses photosynthesis in all green plants, and is therefore of fundamental importance to the viability and productivity of plants, ecosystems, and agriculture. Chloroplasts are, however, extremely vulnerable to environmental stress, on account of the inherent volatility of oxygenic photosynthesis. To counteract this sensitivity, sophisticated systems of chloroplast stress acclimation have evolved, and many of these involve broad proteome changes. Here, we provide an overview of the interlocking and mutually dependent mechanisms of abiotic stress-induced chloroplast proteome remodelling. Topics that are covered in this context include: nucleus to chloroplast signalling mechanisms, with a particular emphasis on the nuclear control of the chloroplast genome; chloroplast to nucleus signalling; and the roles of chloroplast pre-protein import regulation and chloroplast proteases.
Asunto(s)
Cloroplastos/fisiología , Fenómenos Fisiológicos de las Plantas , Proteoma/fisiología , Estrés Fisiológico/fisiología , Proteínas de Plantas/fisiologíaRESUMEN
BACKGROUND: It is unknown whether statin use among people living with HIV results in a reduction in all-cause mortality. We aimed to evaluate the effect of statin use on all-cause mortality among people living with HIV. METHODS: We conducted comprehensive literature searches of Medline, Embase, CINAHL, the Cochrane Library, and cross-references up to April 2018. We included randomised, quasi-randomised trials and prospective cohort studies that examined the association between statin use and cardio-protective and mortality outcomes among people living with HIV. Two reviewers independently abstracted the data. Hazard ratios (HRs) were pooled using empirical Bayesian random-effect meta-analysis. A number of sensitivity analyses were conducted. RESULTS: We included seven studies with a total of 35,708 participants. The percentage of participants on statins across the studies ranged from 8 to 35%. Where reported, the percentage of participants with hypertension ranged from 14 to 35% and 7 to 10% had been diagnosed with diabetes mellitus. Statin use was associated with a 33% reduction in all-cause mortality (pooled HR = 0.67, 95% Credible Interval 0.39 to 0.96). The probability that statin use conferred a moderate mortality benefit (i.e. decreased risk of mortality of at least 25%, HR ≤ 0.75) was 71.5%. Down-weighting and excluding the lower quality studies resulted in a more conservative estimate of the pooled HR. CONCLUSION: Statin use appears to confer moderate mortality benefits in people living with HIV.