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1.
Lancet ; 393(10177): 1216-1224, 2019 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-30799062

RESUMO

BACKGROUND: Directly observed treatment (DOT) has been the standard of care for tuberculosis since the early 1990s, but it is inconvenient for patients and service providers. Video-observed therapy (VOT) has been conditionally recommended by WHO as an alternative to DOT. We tested whether levels of treatment observation were improved with VOT. METHODS: We did a multicentre, analyst-blinded, randomised controlled superiority trial in 22 clinics in England (UK). Eligible participants were patients aged at least 16 years with active pulmonary or non-pulmonary tuberculosis who were eligible for DOT according to local guidance. Exclusion criteria included patients who did not have access to charging a smartphone. We randomly assigned participants to either VOT (daily remote observation using a smartphone app) or DOT (observations done three to five times per week in the home, community, or clinic settings). Randomisation was done by the SealedEnvelope service using minimisation. DOT involved treatment observation by a health-care or lay worker, with any remaining daily doses self-administered. VOT was provided by a centralised service in London. Patients were trained to record and send videos of every dose ingested 7 days per week using a smartphone app. Trained treatment observers viewed these videos through a password-protected website. Patients were also encouraged to report adverse drug events on the videos. Smartphones and data plans were provided free of charge by study investigators. DOT or VOT observation records were completed by observers until treatment or study end. The primary outcome was completion of 80% or more scheduled treatment observations over the first 2 months following enrolment. Intention-to-treat (ITT) and restricted (including only patients completing at least 1 week of observation on allocated arm) analyses were done. Superiority was determined by a 15% difference in the proportion of patients with the primary outcome (60% vs 75%). This trial is registered with the International Standard Randomised Controlled Trials Number registry, number ISRCTN26184967. FINDINGS: Between Sept 1, 2014, and Oct 1, 2016, we randomly assigned 226 patients; 112 to VOT and 114 to DOT. Overall, 131 (58%) patients had a history of homelessness, imprisonment, drug use, alcohol problems or mental health problems. In the ITT analysis, 78 (70%) of 112 patients on VOT achieved ≥80% scheduled observations successfully completed during the first 2 months compared with 35 (31%) of 114 on DOT (adjusted odds ratio [OR] 5·48, 95% CI 3·10-9·68; p<0·0001). In the restricted analysis, 78 (77%) of 101 patients on VOT achieved the primary outcome compared with 35 (63%) of 56 on DOT (adjusted OR 2·52; 95% CI 1·17-5·54; p=0·017). Stomach pain, nausea, and vomiting were the most common adverse events reported (in 16 [14%] of 112 on VOT and nine [8%] of 114 on DOT). INTERPRETATION: VOT was a more effective approach to observation of tuberculosis treatment than DOT. VOT is likely to be preferable to DOT for many patients across a broad range of settings, providing a more acceptable, effective, and cheaper option for supervision of daily and multiple daily doses than DOT. FUNDING: National Institute for Health Research.


Assuntos
Terapia Diretamente Observada/normas , Smartphone/instrumentação , Tuberculose/tratamento farmacológico , Gravação em Vídeo/métodos , Adolescente , Adulto , Protocolos Clínicos , Inglaterra/epidemiologia , Feminino , Humanos , Análise de Intenção de Tratamento/métodos , Londres/epidemiologia , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Autoadministração/métodos , Autoadministração/estatística & dados numéricos , Smartphone/estatística & dados numéricos , Tuberculose/epidemiologia , Adulto Jovem
2.
Thorax ; 73(6): 557-564, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29378859

RESUMO

INTRODUCTION: Urban homeless populations in the UK have been shown to have high rates of active tuberculosis, but less is known about the prevalence of latent tuberculosis infection (LTBI). This study aimed to estimate the prevalence of LTBI among individuals using homeless hostels in London. METHODS: We performed a cross-sectional survey with outcome follow-up in homeless hostels in London. Our primary outcome was prevalence of LTBI. Recruitment for the study took place between May 2011 and June 2013. To estimate an LTBI prevalence of 10% with 95% CIs between 8% and 13%, we required 500 participants. RESULTS: 491/804 (61.1%) individuals agreed to be screened. The prevalence of LTBI was 16.5% (81/491; 95% CI 13.2 to 19.8). In UK-born individuals, a history of incarceration was associated with increased risk of LTBI (OR 3.49; 95% CI 1.10 to 11.04; P=0.018) after adjusting for age, length of time spent homeless and illicit drug use. Of the three subjects who met English treatment guidelines for LTBI at the time of the study, none engaged with services after referral for treatment. Prevalence of past hepatitis B infection was 10.4% (51/489; 95% CI 7.7 to 13.1), and 59.5% (291/489; 95% CI 55.1 to 63.9) of individuals were non-immune. Prevalence of current hepatitis C infection was 10.4% (51/489; 95% CI 7.8 to 13.1). CONCLUSIONS: This study demonstrates the high prevalence of LTBI in homeless people in London and the associated poor engagement with care. There is a large unmet need for LTBI and hepatitis C infection treatment, and hepatitis B vaccination, in this group.


Assuntos
Infecções por HIV/epidemiologia , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Pessoas Mal Alojadas , Tuberculose Latente/epidemiologia , Adulto , Estudos Transversais , Feminino , Infecções por HIV/sangue , Hepatite B/sangue , Hepatite C/sangue , Humanos , Londres/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
3.
Am J Respir Crit Care Med ; 191(12): 1422-31, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25844934

RESUMO

RATIONALE: A high proportion of influenza infections are asymptomatic. Animal and human challenge studies and observational studies suggest T cells protect against disease among those infected, but the impact of T-cell immunity at the population level is unknown. OBJECTIVES: To investigate whether naturally preexisting T-cell responses targeting highly conserved internal influenza proteins could provide cross-protective immunity against pandemic and seasonal influenza. METHODS: We quantified influenza A(H3N2) virus-specific T cells in a population cohort during seasonal and pandemic periods between 2006 and 2010. Follow-up included paired serology, symptom reporting, and polymerase chain reaction (PCR) investigation of symptomatic cases. MEASUREMENTS AND MAIN RESULTS: A total of 1,414 unvaccinated individuals had baseline T-cell measurements (1,703 participant observation sets). T-cell responses to A(H3N2) virus nucleoprotein (NP) dominated and strongly cross-reacted with A(H1N1)pdm09 NP (P < 0.001) in participants lacking antibody to A(H1N1)pdm09. Comparison of paired preseason and post-season sera (1,431 sets) showed 205 (14%) had evidence of infection based on fourfold influenza antibody titer rises. The presence of NP-specific T cells before exposure to virus correlated with less symptomatic, PCR-positive influenza A (overall adjusted odds ratio, 0.27; 95% confidence interval, 0.11-0.68; P = 0.005, during pandemic [P = 0.047] and seasonal [P = 0.049] periods). Protection was independent of baseline antibodies. Influenza-specific T-cell responses were detected in 43%, indicating a substantial population impact. CONCLUSIONS: Naturally occurring cross-protective T-cell immunity protects against symptomatic PCR-confirmed disease in those with evidence of infection and helps to explain why many infections do not cause symptoms. Vaccines stimulating T cells may provide important cross-protective immunity.


Assuntos
Vírus da Influenza A Subtipo H3N2/imunologia , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Pandemias/estatística & dados numéricos , Estações do Ano , Linfócitos T/imunologia , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Inglaterra/epidemiologia , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Adulto Jovem
4.
J Infect Dis ; 205 Suppl 2: S293-300, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22448025

RESUMO

Despite declining incidence in most high-income countries, tuberculosis shows no signs of disappearing in the near future. Although surveillance data from most Western European countries show relatively stable declines in the rate of tuberculosis over the past several decades, some have reported either an increasing rate or a decelerating pace of reduction in recent years. The burden of disease now disproportionately affects high-risk groups such as migrants, homeless persons, and prisoners. In view of the concentration of cases in urban areas and high-risk deprived groups, interventions that may not be efficient when applied to the general population may be highly cost effective when targeted at high-risk groups. In this article, we examine some controversial elements of tuberculosis prevention and control in low-burden countries and recommend issues for further research. In particular, we assess current evidence on the duration of protection by BCG vaccine, the screening of migrants and hard-to-reach groups, and the use of preventive therapy for contacts of cases of infectious multidrug-resistant tuberculosis. This analysis is presented from the perspective of low-tuberculosis-burden, high-income countries attempting to eliminate tuberculosis.


Assuntos
Tuberculose/epidemiologia , Tuberculose/prevenção & controle , Antituberculosos/uso terapêutico , Vacina BCG/imunologia , Controle de Doenças Transmissíveis/métodos , Países Desenvolvidos/economia , Países Desenvolvidos/estatística & dados numéricos , Pessoas Mal Alojadas , Humanos , Incidência , Vigilância da População , Prisioneiros , Fatores de Risco , Sensibilidade e Especificidade , Fatores Socioeconômicos , Migrantes , População Urbana
5.
Plants (Basel) ; 11(17)2022 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-36079606

RESUMO

The genus Viola (Violaceae) is among the 40-50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then-known 400 species were distributed among 14 sections and numerous unranked groups. Here, we provide an updated, comprehensive classification of the genus, based on data from phylogeny, morphology, chromosome counts, and ploidy, and based on modern principles of monophyly. The revision is presented as an annotated global checklist of accepted species of Viola, an updated multigene phylogenetic network and an ITS phylogeny with denser taxon sampling, a brief summary of the taxonomic changes from Becker's classification and their justification, a morphological binary key to the accepted subgenera, sections and subsections, and an account of each infrageneric subdivision with justifications for delimitation and rank including a description, a list of apomorphies, molecular phylogenies where possible or relevant, a distribution map, and a list of included species. We distribute the 664 species accepted by us into 2 subgenera, 31 sections, and 20 subsections. We erect one new subgenus of Viola (subg. Neoandinium, a replacement name for the illegitimate subg. Andinium), six new sections (sect. Abyssinium, sect. Himalayum, sect. Melvio, sect. Nematocaulon, sect. Spathulidium, sect. Xanthidium), and seven new subsections (subsect. Australasiaticae, subsect. Bulbosae, subsect. Clausenianae, subsect. Cleistogamae, subsect. Dispares, subsect. Formosanae, subsect. Pseudorupestres). Evolution within the genus is discussed in light of biogeography, the fossil record, morphology, and particular traits. Viola is among very few temperate and widespread genera that originated in South America. The biggest identified knowledge gaps for Viola concern the South American taxa, for which basic knowledge from phylogeny, chromosome counts, and fossil data is virtually absent. Viola has also never been subject to comprehensive anatomical study. Studies into seed anatomy and morphology are required to understand the fossil record of the genus.

6.
Emerg Infect Dis ; 17(6): 990-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21749759

RESUMO

The United Kingdom implemented a containment strategy for pandemic (H1N1) 2009 through administering antiviral agents (AVs) to patients and their close contacts. This observational household cohort study describes the effect of AVs on household transmission. We followed 285 confirmed primary cases in 259 households with 761 contacts. At 2 weeks, the confirmed secondary attack rate (SAR) was 8.1% (62/761) and significantly higher in persons <16 years of age than in those >50 years of age (18.9% vs. 1.2%, p<0.001). Early (<48 hours) treatment of primary case-patients reduced SAR (4.5% vs. 10.6%, p = 0.003). The SAR in child contacts was 33.3% (10/30) when the primary contact was a woman and 2.9% (1/34) when the primary contact was a man (p = 0.010). Of 53 confirmed secondary case-patients, 45 had not received AV prophylaxis. The effectiveness of AV prophylaxis in preventing infection was 92%.


Assuntos
Antivirais/uso terapêutico , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/tratamento farmacológico , Influenza Humana/transmissão , Pandemias , Profilaxia Pós-Exposição , Adolescente , Adulto , Idoso , Criança , Características da Família , Feminino , Humanos , Influenza Humana/epidemiologia , Influenza Humana/mortalidade , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Reino Unido/epidemiologia , Adulto Jovem
7.
FEBS Lett ; 582(18): 2753-60, 2008 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-18625233

RESUMO

Dicers are associated with double-stranded RNA-binding proteins (dsRBPs) in animals. In the plant, Arabidopsis, there are four dicer-like (DCL) proteins and five potential dsRBPs. These DCLs act redundantly and hierarchically. However, we show there is little or no redundancy or hierarchy amongst the DRBs in their DCL interactions. DCL1 operates exclusively with DRB1 to produce micro (mi)RNAs, DCL4 operates exclusively with DRB4 to produce trans-acting (ta) siRNAs and 21nt siRNAs from viral RNA. DCL2 and DCL3 produce viral siRNAs without requiring assistance from any dsRBP. DRB2, DRB3 and DRB5 appear unnecessary for mi-, tasi-, viral si-, or heterochromatinising siRNA production but act redundantly in a developmental pathway.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Interferência de RNA , RNA de Cadeia Dupla/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Proteínas de Arabidopsis/classificação , Proteínas de Arabidopsis/genética , Elementos de DNA Transponíveis , MicroRNAs/biossíntese , MicroRNAs/química , Mutação , Conformação de Ácido Nucleico , Fenótipo , Filogenia , RNA de Cadeia Dupla/classificação , RNA de Cadeia Dupla/genética , RNA de Plantas/biossíntese , RNA Interferente Pequeno/biossíntese , RNA Interferente Pequeno/química , RNA Viral/biossíntese , RNA Viral/química , Proteínas de Ligação a RNA/classificação , Proteínas de Ligação a RNA/genética , Ribonuclease III/classificação , Ribonuclease III/genética
8.
Lancet Infect Dis ; 8(1): 44-52, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18156088

RESUMO

In several countries, pregnant women are recommended seasonal influenza vaccination and identified as a priority group for vaccination in the event of a pandemic. We review the evidence for the risks of influenza and the risks and benefits of seasonal influenza vaccination in pregnancy. Data on influenza vaccine safety in pregnancy are inadequate, but the few published studies report no serious side-effects in women or their infants, including no indication of harm from vaccination in the first trimester. National policies differ widely, mainly because of the limited data available, particularly on vaccination in the first trimester. The evidence of excess morbidity during seasonal influenza supports vaccinating healthy pregnant women in the second or third trimester and those with comorbidities in any trimester. The evidence of excess mortality in two previous influenza pandemics supports vaccinating in any trimester during a pandemic.


Assuntos
Surtos de Doenças , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Complicações Infecciosas na Gravidez/prevenção & controle , Gravidez/imunologia , Feminino , Política de Saúde , Humanos , Recém-Nascido , Vacinas contra Influenza/efeitos adversos , Influenza Humana/epidemiologia , Influenza Humana/virologia , Resultado da Gravidez , Trimestres da Gravidez , Medição de Risco , Reino Unido/epidemiologia
9.
Int J Epidemiol ; 47(1): 193-201, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29025083

RESUMO

Background: Evidence of protection from childhood Bacillus Calmette-Guerin (BCG) against tuberculosis (TB) in adulthood, when most transmission occurs, is important for TB control and resource allocation. Methods: We conducted a population-based case-control study of protection by BCG given to children aged 12-13 years against tuberculosis occurring 10-29 years later. We recruited UK-born White subjects with tuberculosis and randomly sampled White community controls. Hazard ratios and 95% confidence intervals (CIs) were estimated using case-cohort Cox regression, adjusting for potential confounding factors, including socio-economic status, smoking, drug use, prison and homelessness. Vaccine effectiveness (VE = 1 - hazard ratio) was assessed at successive intervals more than 10 years following vaccination. Results: We obtained 677 cases and 1170 controls after a 65% response rate in both groups. Confounding by deprivation, education and lifestyle factors was slight 10-20 years after vaccination, and more evident after 20 years. VE 10-15 years after vaccination was 51% (95% CI 21, 69%) and 57% (CI 33, 72%) at 15-20 years. Subsequently, BCG protection appeared to wane; 20-25 years VE = 25% (CI -14%, 51%) and 25-29 years VE = 1% (CI -84%, 47%). Based on multiple imputation of missing data (in 17% subjects), VE estimated in the same intervals after vaccination were similar [56% (CI 33, 72%), 57% (CI 36, 71%), 25% (-10, 48%), 21% (-39, 55%)]. Conclusions: School-aged BCG vaccination offered moderate protection against tuberculosis for at least 20 years, which is longer than previously thought. This has implications for assessing the cost-effectiveness of BCG vaccination and when evaluating new TB vaccines.


Assuntos
Vacina BCG/uso terapêutico , Tuberculose/prevenção & controle , Adolescente , Estudos de Casos e Controles , Criança , Estudos de Coortes , Análise Custo-Benefício , Inglaterra/epidemiologia , Feminino , Humanos , Incidência , Masculino , Avaliação de Programas e Projetos de Saúde , Modelos de Riscos Proporcionais , Serviços de Saúde Escolar , Fatores de Tempo , Tuberculose/epidemiologia
10.
Lancet Infect Dis ; 18(10): 1077-1087, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30174209

RESUMO

BACKGROUND: Tackling tuberculosis requires testing and treatment of latent tuberculosis in high-risk groups. The aim of this study was to estimate the predictive values of the tuberculin skin test (TST) and two interferon-γ release assays (IGRAs) for the development of active tuberculosis in high-risk groups-ie, people in recent contact with active tuberculosis cases and from high-burden countries. METHOD: In this prospective cohort study, we recruited participants from 54 centres (eg, clinics, community settings) in London, Birmingham, and Leicester in the UK. Participants were eligible if they were aged 16 years or older and at high risk for latent tuberculosis infection (ie, recent contact with someone with active tuberculosis [contacts] or a migrant who had arrived in the UK in the past 5 years from-or who frequently travelled to-a country with a high burden of tuberculosis [migrants]). Exclusion criteria included prevalent cases of tuberculosis, and participants who were treated for latent tuberculosis after a positive test result in this study. Each participant received three tests (QuantiFERON-TB Gold-In Tube, T-SPOT.TB, and a Mantoux TST). A positive TST result was reported using three thresholds: 5 mm (TST-5), 10 mm (TST-10), and greater than 5 mm in BCG-naive or 15 mm in BCG-vaccinated (TST-15) participants. Participants were followed up from recruitment to development of tuberculosis or censoring. Incident tuberculosis cases were identified by national tuberculosis databases, telephone interview, and review of medical notes. Our primary objective was to estimate the prognostic value of IGRAs compared with TST, assessed by the ratio of incidence rate ratios and predictive values for tuberculosis development. The study was registered with ClinicalTrials.gov, NCT01162265, and is now complete. FINDINGS: Between May 4, 2010, and June 1, 2015, 10 045 people were recruited, of whom 9610 were eligible for inclusion. Of this cohort, 4861 (50·6%) were contacts and 4749 (49·4%) were migrants. Participants were followed up for a median of 2·9 years (range 21 days to 5·9 years). 97 (1·0%) of 9610 participants developed active tuberculosis (77 [1·2%] of 6380 with results for all three tests). In all tests, annual incidence of tuberculosis was very low in those who tested negatively (ranging from 1·2 per 1000 person-years, 95% CI 0·6-2·0 for TST-5 to 1·9 per 1000 person-years, 95% CI 1·3-2·7, for QuantiFERON-TB Gold In-Tube). Annual incidence in participants who tested positively were highest for T-SPOT.TB (13·2 per 1000 person-years, 95% CI 9·9-17·4), TST-15 (11·1 per 1000 person-years, 8·3-14·6), and QuantiFERON-TB Gold In-Tube (10·1 per 1000 person-years, 7·4-13·4). Positive results for these tests were significantly better predictors of progression than TST-10 and TST-5 (eg, ratio of test positivity rates in those progressing to tuberculosis compared with those not progressing T-SPOT.TB vs TST-5: 1·99, 95% CI 1·68-2·34; p<0·0001). However, TST-5 identified a higher proportion of participants who progressed to active tuberculosis (64 [83%] of 77 tested) than all other tests and TST thresholds (≤75%). INTERPRETATION: IGRA-based or BCG-stratified TST strategies appear most suited to screening for potential disease progression among high-risk groups. Further work will be needed to assess country-specific cost-effectiveness of each screening test, and in the absence of highly specific diagnostic tests, cheap non-toxic treatments need to be developed that could be given to larger groups of people at potential risk. FUNDING: National Institute for Health Research Health Technology Assessment Programme 08-68-01.


Assuntos
Testes de Liberação de Interferon-gama , Teste Tuberculínico , Tuberculose/diagnóstico , Adulto , Vacina BCG/imunologia , Feminino , Guias como Assunto , Humanos , Masculino , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Tuberculose/prevenção & controle , Reino Unido
11.
J Epidemiol Community Health ; 61(4): 302-7, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17372289

RESUMO

BACKGROUND: Tuberculosis treatment outcome monitoring was introduced in England, Wales and Northern Ireland in 2002 based on cases reported in 2001. OBJECTIVE: To estimate the proportion of treatment success and to identify predictors of non-completion for cases reported in 2001. METHOD: At 12 months after the start of treatment, outcome was assessed according to a protocol based on standardised European recommendations. RESULTS: The proportion of cases completing treatment by 12 months was 79% if calculated for cases in whom outcome information was reported, and 62% of all cases regardless of whether information on outcome was reported or not. Of the new smear-positive pulmonary cases for whom information on outcome was reported, 77% completed treatment. Non-completion of treatment was associated with male sex, age > or =65 years, recent entry into UK for those born abroad, residence outside London, pulmonary disease and drug resistance. CONCLUSIONS: Despite the resources of an industrialised country with a low incidence of tuberculosis, the World Health Organization treatment success target of 85% was not achieved. This was partly due to the number of deaths in the elderly, and partly due to missing outcome information for 21% of the cases. As in other low-incidence countries, additional outcome measures such as the proportion of those aged <65 years completing treatment would provide a more comparable indicator for assessment of treatment success. This first year of data collection has shown the importance of increasing the proportion of cases for whom outcome is ascertained, and of ensuring the validity of information provided.


Assuntos
Tuberculose/tratamento farmacológico , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/efeitos adversos , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Fatores de Risco , Distribuição por Sexo , Resultado do Tratamento , Tuberculose/epidemiologia , Tuberculose/mortalidade , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/mortalidade , Reino Unido/epidemiologia
12.
FEBS Lett ; 580(10): 2442-50, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16638569

RESUMO

Most multicellular organisms regulate developmental transitions by microRNAs, which are generated by an enzyme, Dicer. Insects and fungi have two Dicer-like genes, and many animals have only one, yet the plant, Arabidopsis, has four. Examining the poplar and rice genomes revealed that they contain five and six Dicer-like genes, respectively. Analysis of these genes suggests that plants require a basic set of four Dicer types which were present before the divergence of mono- and dicotyledonous plants ( approximately 200 million years ago), but after the divergence of plants from green algae. A fifth type of Dicer seems to have evolved in monocots.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Evolução Molecular , Oryza/genética , Populus/genética , Genes de Plantas , Especificidade da Espécie
13.
BMJ Open ; 6(5): e010608, 2016 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-27142858

RESUMO

OBJECTIVE: To review all notified cases of leprosy in England and Wales between 1953 and 2012. DESIGN: National surveillance study of all reported cases. SETTING: England and Wales. OUTCOME: Number and characteristics of reported cases. RESULTS: During this period, a total of 1449 leprosy cases were notified. The incidence fell from 356 new cases notified between 1953 and 1962 to 139 new cases between 2003 and 2012. Where data were available, leprosy was more common in men, 15-45 year olds and those from the Indian subcontinent. There was considerable undernotification in 2001-2012. CONCLUSIONS: The high level of under-reporting indicates a need for improved surveillance in the UK. Public Health England, in collaboration with the UK Panel of Leprosy opinion, has revised the UK Memorandum on Leprosy in order to provide updated guidance on diagnostic procedures, treatment, case management, contact tracing and notification.


Assuntos
Hanseníase/epidemiologia , Vigilância da População , Adolescente , Adulto , Fatores Etários , Bangladesh/etnologia , Notificação de Doenças/estatística & dados numéricos , Inglaterra/epidemiologia , Feminino , Humanos , Incidência , Índia/etnologia , Masculino , Fatores Sexuais , País de Gales/epidemiologia , Adulto Jovem
14.
Arch Dis Child ; 101(1): 91-5, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26672098

RESUMO

In 2015, the UK became the first country in the world to have a comprehensive routine meningococcal vaccine programme targeting all of the main capsular groups of N. meningitidis. 1 An infant vaccine programme against meningococcal capsular group B Neisseria meningitidis (MenB) was launched from 1st September with an aim to reduce endemic MenB disease in early childhood. On 1st August 2015, an adolescent programme against groups A, C, W and Y meningococci (MenACWY) was rolled out to halt a growing outbreak of capsular group W disease (MenW) caused by a hypervirulent clone of N. meningitidis, in addition to maintaining control against MenC disease provided by the current adolescent programme. 2.


Assuntos
Programas de Imunização , Infecções Meningocócicas/prevenção & controle , Vacinas Meningocócicas , Adolescente , Distribuição por Idade , Criança , Pré-Escolar , Inglaterra/epidemiologia , Humanos , Lactente , Recém-Nascido , Infecções Meningocócicas/epidemiologia , Reino Unido , Vacinas Conjugadas , Adulto Jovem
15.
FEBS Lett ; 579(26): 5982-7, 2005 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-16139270

RESUMO

Since the discovery of RNAi, its mechanism in plants and animals has been intensively studied, widely exploited as a research tool, and used for a number of potential commercial applications. In this article, we discuss the platforms for delivering RNAi in plants. We provide a brief background to these platforms and concentrate on discussing the more recent advances, comparing the RNAi technologies used in plants with those used in animals, and trying to predict the ways in which RNAi technologies may further develop.


Assuntos
Técnicas de Transferência de Genes , Interferência de RNA , RNA de Plantas/genética , Animais , DNA/química , Inativação Gênica , Genes de Plantas , Técnicas Genéticas , Vetores Genéticos , MicroRNAs/química , Vírus de Plantas/genética , Plasmídeos/metabolismo , RNA de Cadeia Dupla , RNA Interferente Pequeno/metabolismo , Complexo de Inativação Induzido por RNA , Transgenes
16.
Lancet Respir Med ; 2(6): 445-54, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24717637

RESUMO

BACKGROUND: Assessment of the effect of influenza on populations, including risk of infection, illness if infected, illness severity, and consultation rates, is essential to inform future control and prevention. We aimed to compare the community burden and severity of seasonal and pandemic influenza across different age groups and study years and gain insight into the extent to which traditional surveillance underestimates this burden. METHODS: Using preseason and postseason serology, weekly illness reporting, and RT-PCR identification of influenza from nasal swabs, we tracked the course of seasonal and pandemic influenza over five successive cohorts (England 2006-11; 5448 person-seasons' follow-up). We compared burden and severity of seasonal and pandemic strains. We weighted analyses to the age and regional structure of England to give nationally representative estimates. We compared symptom profiles over the first week of illness for different strains of PCR-confirmed influenza and non-influenza viruses using ordinal logistic regression with symptom severity grade as the outcome variable. FINDINGS: Based on four-fold titre rises in strain-specific serology, on average influenza infected 18% (95% CI 16-22) of unvaccinated people each winter. Of those infected there were 69 respiratory illnesses per 100 person-influenza-seasons compared with 44 per 100 in those not infected with influenza. The age-adjusted attributable rate of illness if infected was 23 illnesses per 100 person-seasons (13-34), suggesting most influenza infections are asymptomatic. 25% (18-35) of all people with serologically confirmed infections had PCR-confirmed disease. 17% (10-26) of people with PCR-confirmed influenza had medically attended illness. These figures did not differ significantly when comparing pandemic with seasonal influenza. Of PCR-confirmed cases, people infected with the 2009 pandemic strain had markedly less severe symptoms than those infected with seasonal H3N2. INTERPRETATION: Seasonal influenza and the 2009 pandemic strain were characterised by similar high rates of mainly asymptomatic infection with most symptomatic cases self-managing without medical consultation. In the community the 2009 pandemic strain caused milder symptoms than seasonal H3N2. FUNDING: Medical Research Council and the Wellcome Trust.


Assuntos
DNA Viral/análise , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/epidemiologia , Pandemias , Estações do Ano , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Inglaterra/epidemiologia , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Influenza Humana/diagnóstico , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Sistema de Registros , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto Jovem
17.
Methods Mol Biol ; 894: 17-38, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22678570

RESUMO

Given the widespread impact of RNA silencing on the Arabidopsis thaliana genome, it is indeed remarkable that this means of gene regulation went undiscovered for so long. Since the publication of landmark papers in 1998 (Fire et al., Nature 391:806-811, 1998; Waterhouse et al., Proc Natl Acad Sci U S A 95:13959-13964, 1998), intense research efforts have resulted in much progress from the speculation of Mello and colleagues that "the mechanisms underlying RNA interference probably exist for a biological purpose" (Fire et al., Nature 391:806-811, 1998). Across the eukaryotic kingdom, with the notable exception of Saccharomyces cerevisiae (Moazed, Science 326:544-550, 2009), the importance of small RNA-driven gene regulation has been recognized and implicated in central developmental processes as well as in aberrant and diseased states. Plants have by far the most complex RNA-based control of gene expression (Wang et al., Floriculture, ornamental and plant biotechnology, vol. III, 2006). Four distinct RNA silencing pathways have been recognized in plants, albeit with considerable conservation of the molecular components. These pathways are directed by various small RNA species, including microRNAs (miRNAs), trans-acting small interfering RNAs (siRNA) (ta-siRNAs), repeat-associated siRNAs (ra-siRNAs), and natural antisense transcript siRNAs (nat-siRNAs). The effective functionality of each of these pathways appear to be fundamental to the integrity of A. thaliana. Furthermore, in response to viral invasion, plants synthesize viral sRNAs as a means of defense. This process may in fact reflect the ancient origins of RNA silencing: plants may have evolved RNA silencing pathways as a defense mechanism against foreign nucleic acid species in the absence of an immune system (Wang and Metzlaff, Curr Opin Plant Biol 8:216-222, 2005). The generation of viral siRNAs is a particularly interesting illustration of RNA silencing as it provides a context to explore the potential to harness a naturally occurring system to the end goal of artificially engineering viral resistance.


Assuntos
Arabidopsis , Doenças das Plantas/virologia , Vírus de Plantas/patogenicidade , Interferência de RNA , RNA Interferente Pequeno , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/virologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Metilação de DNA , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Doenças das Plantas/genética , Vírus de Plantas/genética , RNA de Cadeia Dupla/genética , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo
18.
Methods Mol Biol ; 894: 173-89, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22678580

RESUMO

In this chapter, we detail some of the methods available to the researcher for isolating and analyzing virus-derived small RNAs (vsRNAs). These methods have been successfully used for four plant viruses: Cucumber mosaic virus (CMV), including the CMV Y-Satellite, Turnip mosaic virus (TuMV), Potato leaf roll virus (PLRV), and Tomato spotted wilt virus (TSWV) from inoculated Arabidopsis thaliana plants (Fusaro et al. EMBO Rep 7:1168-1175, 2006; Curtin et al. FEBS Lett 582:2753-2760, 2008). The protocols presented here can also be employed for the isolation of non-virus related small RNAs such as microRNAs (miRNAs) and hairpin RNA (hpRNA).


Assuntos
Arabidopsis/virologia , MicroRNAs/isolamento & purificação , Doenças das Plantas/virologia , Vírus de Plantas/genética , RNA Interferente Pequeno/isolamento & purificação , RNA Viral/isolamento & purificação , Arabidopsis/genética , Cucumovirus/genética , Luteoviridae/genética , MicroRNAs/análise , MicroRNAs/genética , RNA Interferente Pequeno/análise , RNA Interferente Pequeno/genética , RNA Viral/análise , RNA Viral/genética , Tospovirus/genética , Tymovirus/genética
19.
PLoS One ; 7(1): e30279, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22291929

RESUMO

BACKGROUND: The World Health Organization and European Centre for Disease Prevention and Control have highlighted the importance of establishing systems to monitor severe influenza. Following the H1N1 (2009) influenza pandemic, a sentinel network of 23 Trusts, the UK Severe Influenza Surveillance System (USISS), was established to monitor hospitalisations due to confirmed seasonal influenza in England. This article presents the results of the first season of operation of USISS in 2010/11. METHODOLOGY/PRINCIPAL FINDINGS: A case was defined as a person hospitalised with confirmed influenza of any type. Weekly aggregate numbers of hospitalised influenza cases, broken down by flu type and level of care, were submitted by participating Trusts. Cases in 2010/11 were compared to cases during the 2009 pandemic in hospitals with available surveillance data for both time periods (n = 19). An unexpected resurgence in seasonal A/H1N1 (2009) influenza activity in England was observed in December 2010 with reports of severe disease. Reported cases over the period of 4 October 2010 to 13 February 2011 were mostly due to influenza A/H1N1 (2009). One thousand and seventy-one cases of influenza A/H1N1 (2009) occurred over this period compared to 409 at the same Trusts over the 2009/10 pandemic period (1 April 2009 to 6 January 2010). Median age of influenza A/H1N1 (2009) cases in 2010/11 was 35 years, compared with 20 years during the pandemic (p = <0.0001). CONCLUSIONS/SIGNIFICANCE: The Health Protection Agency successfully established a sentinel surveillance system for severe influenza in 2010/11, detecting a rise in influenza cases mirroring other surveillance indicators. The data indicate an upward shift in the age-distribution of influenza A/H1N1 (2009) during the 2010/11 influenza season as compared to the 2009/10 pandemic. Systems to enable the ongoing surveillance of severe influenza will be a key component in understanding and responding to the evolving epidemiology of influenza in the post-pandemic era.


Assuntos
Hospitalização/estatística & dados numéricos , Influenza Humana/epidemiologia , Pandemias/estatística & dados numéricos , Vigilância de Evento Sentinela , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Inglaterra/epidemiologia , Humanos , Lactente , Recém-Nascido , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/terapia , Pessoa de Meia-Idade , Projetos Piloto , Índice de Gravidade de Doença , Fatores de Tempo , Adulto Jovem
20.
BMJ Open ; 2(5)2012.
Artigo em Inglês | MEDLINE | ID: mdl-22964115

RESUMO

OBJECTIVE: Assess the current BCG vaccination policies and delivery pathways for immunisation in Primary Care Trusts (PCTs) in England since the 2005 change in recommendations. DESIGN: A survey of key informants across PCTs using a standardised, structured questionnaire. SETTING: 152 PCTs in England. RESULTS: Complete questionnaires were returned from 127 (84%) PCTs. Sixteen (27%) PCTs reported universal infant vaccination and 111 (73%) had selective infant vaccination. Selective vaccination outside infancy was also reported from 94 (74%) PCTs. PCTs with selective infant policy most frequently vaccinated on postnatal wards (51/102, 50%), whereas PCTs with universal infant vaccination most frequently vaccinated in community clinics (9/13, 69%; p=0.011). To identify and flag up eligible infants in PCTs with targeted infant immunisation, those who mostly vaccinate on postnatal wards depend on midwives and maternity records, whereas those who vaccinate primarily in the community rely more often on various healthcare professionals. CONCLUSIONS: Targeted infant vaccination has been implemented in most PCTs across the UK. PCTs with selective infant vaccination provide BCG vaccine via a greater variety of healthcare professionals than those with universal infant vaccination policies. Data on vaccine coverage would help evaluate the effectiveness of delivery. Interruptions of delivery noted here emphasise the importance of not just an agreed, standardised, local pathway, but also a named person in charge.

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