123 research outputs found
Rad51-Rad52 mediated maintenance of centromeric chromatin in candida albicans
La ubicación específica de un centrómero en la mayoría de los eucariotas no depende únicamente de la secuencia de ADN. Sin embargo, los determinantes no genéticos de identidad de un centrómero no están claramente definidos. Aunque varios mecanismos, de forma individual o en conjunto, pueden especificar centrómeros epigenéticos, la mayoría de los estudios en este área se centran en un factor universal, un centromerospecific histona H3 variante CENP-A, a menudo considerado como el determinante de la identidad epigenética del centrómero. A pesar de la sincronización variable de su carga en centrómeros través de las especies, una replicación junto a una deposición en fase temprana S de CENP-A se encuentra en la mayoría de los centrómeros de levadura. Centrómeros son las regiones más tempranas de replicación cromosómica en una levadura en ciernes patógeno Candida albicans. Al aplicar un ensayo de electroforesis en gel de agarosa de dos dimensiones se identifican los orígenes de replicación (ORI7-LI y ORI7-RI) proxima a un centrómero temprano replicante (CEN7) en C. albicans. Se demuestra que las horquillas de replicación se estancan en CEN7 de una manera dependiente del cinetocoro y el estancamiento tenedor se reduce en ausencia de la recombinación homóloga (HR) proteínas Rad51 y Rad52. La supresión de ORI7-RI provoca una reducción significativa en la señal de tenedor estancado y una mayor tasa de pérdida del cromosoma alterado 7. Las proteínas de recursos humanos, Rad51 y Rad52, han demostrado que desempeñan un papel en el reinicio del tenedor. La microscopía confocal muestra cinetocoros declustered en rad51 y rad52 mutantes, que son evidencia de la disrupción cinetocoro. Los niveles de CENP-ACaCse4 en centrómeros, como se determina por los experimentos de inmunoprecipitación de la cromatina (ChIP), se reducen en ausencia de Rad51 / Rad52 que resulta en la interrupción de la estructura cinetocoro. Además, el análisis de transferencia Western revela que las moléculas de CENP-A deslocalizados en mutantes de recursos humanos se degradan de un modo similar como en otros mutantes kinetochore descritos antes. Finalmente, los ensayos de co-inmunoprecipitación indican que Rad51 y Rad52 interactuan físicamente con CENPA CaCse4 in vivo. Por lo tanto, las proteínas Rad51 y Rad52 de recursos epigenéticos humanos mantienen el funcionamiento del centrómero mediante la regulación de los niveles de CENPA CaCse4 en los sitios de parada programados en los principios centrómeros a replicar.Specification of the centromere location in most eukaryotes is not solely dependent on the DNA sequence. However, the non-genetic determinants of centromere identity are not clearly defined. While multiple mechanisms, individually or in concert, may specify centromeres epigenetically, most studies in this area are focused on a universal factor, a centromerespecific histone H3 variant CENP-A, often considered as the epigenetic determinant of centromere identity. In spite of variable timing of its loading at centromeres across species, a replication coupled early S phase deposition of CENP-A is found in most yeast centromeres. Centromeres are the earliest replicating chromosomal regions in a pathogenic budding yeast Candida albicans. Using a 2-dimensional agarose gel electrophoresis assay, we identify replication origins (ORI7-LI and ORI7-RI) proximal to an early replicating centromere (CEN7) in C. albicans. We show that the replication forks stall at CEN7 in a kinetochore dependent manner and fork stalling is reduced in the absence of the homologous recombination (HR) proteins Rad51 and Rad52. Deletion of ORI7-RI causes a significant reduction in the stalled fork signal and an increased loss rate of the altered chromosome 7. The HR proteins, Rad51 and Rad52, have been shown to play a role in fork restart. Confocal microscopy shows declustered kinetochores in rad51 and rad52 mutants, which are evidence of kinetochore disintegrity. CENP-ACaCse4 levels at centromeres, as determined by chromatin immunoprecipitation (ChIP) experiments, are reduced in absence of Rad51/Rad52 resulting in disruption of the kinetochore structure. Moreover, western blot analysis reveals that delocalized CENP-A molecules in HR mutants degrade in a similar fashion as in other kinetochore mutants described before. Finally, co-immunoprecipitation assays indicate that Rad51 and Rad52 physically interact with CENPA CaCse4 in vivo. Thus, the HR proteins Rad51 and Rad52 epigenetically maintain centromere functioning by regulating CENPA CaCse4 levels at the programmed stall sites of early replicating centromeresK. Sanyal y D. D. Dubey han recibido financiación del Government of India. Department of Biotechnology
S. Mitra fue Senior Research Fellowship financiado por Council of Scientific and Industrial Research
K Sanyal recibió ayuda de Jawaharlal Nehru Centre for Advanced Scientific Research
G. Larriba fue financiado por Junta de Extremadura, Ayuda a grupos CCV014, Fondos FEDER; y por el Ministerio de Ciencia e Innovación, SAF2010-19848peerReviewe
Effect Of Fiber Loading On The Mechanical Properties Of Bagasse Fiber–Reinforced Polypropylene Composites
Global impact of bronchiectasis and cystic fibrosis
Educational aims
To recognise the clinical and radiological presentation of the spectrum of diseases associated with bronchiectasis.;
To understand variation in the aetiology, microbiology and burden of bronchiectasis and cystic fibrosis across different global healthcare systems.; Bronchiectasis is the term used to refer to dilatation of the bronchi that is usually permanent and is associated with a clinical syndrome of cough, sputum production and recurrent respiratory infections. It can be caused by a range of inherited and acquired disorders, or may be idiopathic in nature. The most well recognised inherited disorder in Western countries is cystic fibrosis (CF), an autosomal recessive condition that leads to progressive bronchiectasis, bacterial infection and premature mortality. Both bronchiectasis due to CF and bronchiectasis due to other conditions are placing an increasing burden on healthcare systems internationally. Treatments for CF are becoming more effective leading to more adult patients with complex healthcare needs. Bronchiectasis not due to CF is becoming increasingly recognised, particularly in the elderly population. Recognition is important and can lead to identification of the underlying cause, appropriate treatment and improved quality of life. The disease is highly diverse in its presentation, requiring all respiratory physicians to have knowledge of the different “bronchiectasis syndromes”. The most common aetiologies and presenting syndromes vary depending on geography, with nontuberculous mycobacterial disease predominating in some parts of North America, post-infectious and idiopathic disease predominating in Western Europe, and post-tuberculosis bronchiectasis dominating in South Asia and Eastern Europe. Ongoing global collaborative studies will greatly advance our understanding of the international impact of bronchiectasis and CF
The European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC):experiences from a successful ERS Clinical Research Collaboration
In contrast to airway diseases like chronic obstructive pulmonary disease or asthma, and rare diseases such as cystic fibrosis, there has been little research and few clinical trials in bronchiectasis. Guidelines are primarily based on expert opinion and treatment is challenging because of the heterogeneous nature of the disease. In an effort to address decades of underinvestment in bronchiectasis research, education and clinical care, the European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC) was established in 2012 as a collaborative pan-European network to bring together bronchiectasis researchers. The European Respiratory Society officially funded EMBARC in 2013 as a Clinical Research Collaboration, providing support and infrastructure to allow the project to grow. EMBARC has now established an international bronchiectasis registry that is active in more than 30 countries both within and outside Europe. Beyond the registry, the network participates in designing and facilitating clinical trials, has set international research priorities, promotes education and has participated in producing the first international bronchiectasis guidelines. This manuscript article the development, structure and achievements of EMBARC from 2012 to 2017. EDUCATIONAL AIMS: To understand the role of Clinical Research Collaborations as the major way in which the European Respiratory Society can stimulate clinical research in different disease areasTo understand some of the key features of successful disease registriesTo review key epidemiological, clinical and translational studies of bronchiectasis contributed by the European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC) project in the past 5 yearsTo understand the key research priorities identified by EMBARC for the next 5 years
Objective sputum colour assessment and clinical outcomes in bronchiectasis: data from the European Bronchiectasis Registry (EMBARC)
Background A validated 4-point sputum colour chart can be used to objectively evaluate the levels of airway inflammation in bronchiectasis patients. In the European Bronchiectasis Registry (EMBARC), we tested whether sputum colour would be associated with disease severity and clinical outcomes. Methods We used a prospective, observational registry of adults with bronchiectasis conducted in 31 countries. Patients who did not produce spontaneous sputum were excluded from the analysis. The Murray sputum colour chart was used at baseline and at follow-up visits. Key outcomes were frequency of exacerbations, hospitalisations for severe exacerbations and mortality during up to 5-year follow-up. Results 13 484 patients were included in the analysis. More purulent sputum was associated with lower forced expiratory volume in 1 s (FEV 1), worse quality of life, greater bacterial infection and a higher bronchiectasis severity index. Sputum colour was strongly associated with the risk of future exacerbations during follow-up. Compared to patients with mucoid sputum (reference group), patients with mucopurulent sputum experienced significantly more exacerbations (incident rate ratio (IRR) 1.29, 95% CI 1.22–1.38; p<0.0001), while the rates were even higher for patients with purulent (IRR 1.55, 95% CI 1.44–1.67; p<0.0001) and severely purulent sputum (IRR 1.91, 95% CI 1.52–2.39; p<0.0001). Hospitalisations for severe exacerbations were also associated with increasing sputum colour with rate ratios, compared to patients with mucoid sputum, of 1.41 (95% CI 1.29–1.56; p<0.0001), 1.98 (95% CI 1.77–2.21; p<0.0001) and 3.05 (95% CI 2.25–4.14; p<0.0001) for mucopurulent, purulent and severely purulent sputum, respectively. Mortality was significantly increased with increasing sputum purulence, hazard ratio 1.12 (95% CI 1.01–1.24; p=0.027), for each increment in sputum purulence. Conclusion Sputum colour is a simple marker of disease severity and future risk of exacerbations, severe exacerbations and mortality in patients with bronchiectasis.</p
Objective sputum colour assessment and clinical outcomes in bronchiectasis: data from the European Bronchiectasis Registry (EMBARC)
Background A validated 4-point sputum colour chart can be used to objectively evaluate the levels of airway inflammation in bronchiectasis patients. In the European Bronchiectasis Registry (EMBARC), we tested whether sputum colour would be associated with disease severity and clinical outcomes. Methods We used a prospective, observational registry of adults with bronchiectasis conducted in 31 countries. Patients who did not produce spontaneous sputum were excluded from the analysis. The Murray sputum colour chart was used at baseline and at follow-up visits. Key outcomes were frequency of exacerbations, hospitalisations for severe exacerbations and mortality during up to 5-year follow-up. Results 13 484 patients were included in the analysis. More purulent sputum was associated with lower forced expiratory volume in 1 s (FEV 1), worse quality of life, greater bacterial infection and a higher bronchiectasis severity index. Sputum colour was strongly associated with the risk of future exacerbations during follow-up. Compared to patients with mucoid sputum (reference group), patients with mucopurulent sputum experienced significantly more exacerbations (incident rate ratio (IRR) 1.29, 95% CI 1.22–1.38; p<0.0001), while the rates were even higher for patients with purulent (IRR 1.55, 95% CI 1.44–1.67; p<0.0001) and severely purulent sputum (IRR 1.91, 95% CI 1.52–2.39; p<0.0001). Hospitalisations for severe exacerbations were also associated with increasing sputum colour with rate ratios, compared to patients with mucoid sputum, of 1.41 (95% CI 1.29–1.56; p<0.0001), 1.98 (95% CI 1.77–2.21; p<0.0001) and 3.05 (95% CI 2.25–4.14; p<0.0001) for mucopurulent, purulent and severely purulent sputum, respectively. Mortality was significantly increased with increasing sputum purulence, hazard ratio 1.12 (95% CI 1.01–1.24; p=0.027), for each increment in sputum purulence. Conclusion Sputum colour is a simple marker of disease severity and future risk of exacerbations, severe exacerbations and mortality in patients with bronchiectasis.</p
Bronchiectasis in India:results from the European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC) and Respiratory Research Network of India Registry
BACKGROUND: Bronchiectasis is a common but neglected chronic lung disease. Most epidemiological data are limited to cohorts from Europe and the USA, with few data from low-income and middle-income countries. We therefore aimed to describe the characteristics, severity of disease, microbiology, and treatment of patients with bronchiectasis in India. METHODS: The Indian bronchiectasis registry is a multicentre, prospective, observational cohort study. Adult patients ( 6518 years) with CT-confirmed bronchiectasis were enrolled from 31 centres across India. Patients with bronchiectasis due to cystic fibrosis or traction bronchiectasis associated with another respiratory disorder were excluded. Data were collected at baseline (recruitment) with follow-up visits taking place once per year. Comprehensive clinical data were collected through the European Multicentre Bronchiectasis Audit and Research Collaboration registry platform. Underlying aetiology of bronchiectasis, as well as treatment and risk factors for bronchiectasis were analysed in the Indian bronchiectasis registry. Comparisons of demographics were made with published European and US registries, and quality of care was benchmarked against the 2017 European Respiratory Society guidelines. FINDINGS: From June 1, 2015, to Sept 1, 2017, 2195 patients were enrolled. Marked differences were observed between India, Europe, and the USA. Patients in India were younger (median age 56 years [IQR 41-66] vs the European and US registries; p<0\ub70001]) and more likely to be men (1249 [56\ub79%] of 2195). Previous tuberculosis (780 [35\ub75%] of 2195) was the most frequent underlying cause of bronchiectasis and Pseudomonas aeruginosa was the most common organism in sputum culture (301 [13\ub77%]) in India. Risk factors for exacerbations included being of the male sex (adjusted incidence rate ratio 1\ub717, 95% CI 1\ub703-1\ub732; p=0\ub7015), P aeruginosa infection (1\ub729, 1\ub710-1\ub750; p=0\ub7001), a history of pulmonary tuberculosis (1\ub720, 1\ub707-1\ub734; p=0\ub7002), modified Medical Research Council Dyspnoea score (1\ub732, 1\ub725-1\ub739; p<0\ub70001), daily sputum production (1\ub716, 1\ub703-1\ub730; p=0\ub7013), and radiological severity of disease (1\ub703, 1\ub701-1\ub704; p<0\ub70001). Low adherence to guideline-recommended care was observed; only 388 patients were tested for allergic bronchopulmonary aspergillosis and 82 patients had been tested for immunoglobulins. INTERPRETATION: Patients with bronchiectasis in India have more severe disease and have distinct characteristics from those reported in other countries. This study provides a benchmark to improve quality of care for patients with bronchiectasis in India. FUNDING: EU/European Federation of Pharmaceutical Industries and Associations Innovative Medicines Initiative inhaled Antibiotics in Bronchiectasis and Cystic Fibrosis Consortium, European Respiratory Society, and the British Lung Foundation
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