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Rationale: Progressive lung function loss is recognized in chronic obstructive pulmonary disease (COPD); however, no study concurrently evaluates how accelerated lung function decline relates to mucus properties and the microbiome in COPD. Objectives: Longitudinal assessment of mucus and microbiome changes accompanying accelerated lung function decline in patients COPD. Methods: This was a prospective, longitudinal assessment of the London COPD cohort exhibiting the greatest FEV1 decline (n = 30; accelerated decline; 156 ml/yr FEV1 loss) and with no FEV1 decline (n = 28; nondecline; 49 ml/yr FEV1 gain) over time. Lung microbiomes from paired sputum (total 116 specimens) were assessed by shotgun metagenomics and corresponding mucus profiles evaluated for biochemical and biophysical properties. Measurements and Main Results: Biochemical and biophysical mucus properties are significantly altered in the accelerated decline group. Unsupervised principal component analysis showed clear separation, with mucus biochemistry associated with accelerated decline, whereas biophysical mucus characteristics contributed to interindividual variability. When mucus and microbes are considered together, an accelerated decline mucus-microbiome association emerges, characterized by increased mucin (MUC5AC [mucin 5AC] and MUC5B [mucin 5B]) concentration and the presence of Achromobacter and Klebsiella. As COPD progresses, mucus-microbiome shifts occur, initially characterized by low mucin concentration and transition from viscous to elastic dominance accompanied by the commensals Veillonella, Gemella, Rothia, and Prevotella (Global Initiative for Chronic Obstructive Lung Disease [GOLD] A and B) before transition to increased mucus viscosity, mucins, and DNA concentration together with the emergence of pathogenic microorganisms including Haemophilus, Moraxella, and Pseudomonas (GOLD E). Conclusions: Mucus-microbiome associations evolve over time with accelerated lung function decline, symptom progression, and exacerbations affording fresh therapeutic opportunities for early intervention.
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Microbiota , Moco , Enfermedad Pulmonar Obstructiva Crónica , Esputo , Humanos , Enfermedad Pulmonar Obstructiva Crónica/microbiología , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Masculino , Femenino , Anciano , Persona de Mediana Edad , Estudios Prospectivos , Esputo/microbiología , Moco/microbiología , Estudios Longitudinales , Progresión de la Enfermedad , Mucina 5B/metabolismo , Volumen Espiratorio Forzado , Mucina 5AC/metabolismo , LondresRESUMEN
RATIONALE: Respiratory syncytial virus (RSV) is a common global respiratory virus increasingly recognized as a major pathogen in frail older adults and as a cause of chronic obstructive pulmonary disease (COPD) exacerbations. There is no single test for RSV in adults with acceptable diagnostic accuracy. Trials of RSV vaccines have recently shown excellent safety and efficacy against RSV in older adults; defining the frequency of RSV-related community infections and COPD exacerbations is important for vaccine deployment decisions. OBJECTIVES: This prospective study aimed to establish the frequency of outpatient-managed RSV-related exacerbations of COPD in two well-characterized patient cohorts using a combination of diagnostic methods. METHODS: Participants were recruited at specialist clinics in London, UK and Groningen, NL from 2017 and observed for three consecutive RSV seasons, during exacerbations and at least twice yearly. RSV infections were detected by reverse transcription-polymerase chain reaction (RT-PCR) and serologic testing. MEASUREMENTS AND MAIN RESULTS: 377 patients with COPD attended 1,999 clinic visits and reported 310 exacerbations. There were 27 RSV-related exacerbations (8·7% of total); of these, seven were detected only on PCR, 16 only on serology and 4 by both methods. Increases in RSV specific N-protein antibody were as sensitive as antibody to pre-F or post-F for serodiagnosis of RSV related exacerbations. CONCLUSIONS: RSV is associated with 8.7% of outpatient managed COPD exacerbations in this study. Antibodies to RSV-N protein may have diagnostic value, potentially important in a vaccinated population. The introduction of vaccines that prevent RSV is expected to benefit patients with COPD. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
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PURPOSE OF REVIEW: Chronic obstructive pulmonary disease (COPD) is preventable disease and yet it remains the third greatest cause of death worldwide. This review focuses on recent updates in COPD research which have had an impact on our understanding of the epidemiology and pathophysiology of COPD. RECENT FINDINGS: Epidemiological studies of COPD have moved towards trying to understand the global impact of COPD particularly in low- and middle-income countries where disease prevalence continues to increase. In addition, we are beginning to uncover the impact of air pollution on COPD development with recent work showing a relationship between air pollution and COPD exacerbations. Advances in understanding early origins and early development of COPD have the potential to intervene earlier in the disease course to prevent disease progression. Although biomarkers such as peripheral blood eosinophilia have led to trials of biologic agents in COPD suggesting we may be entering an exciting new biologic era in COPD. SUMMARY: Recent advances suggest there may be a relationship between air pollution and COPD exacerbations. This requires further research to influence environmental policy. New clinical trials of biologics targeting TH2 inflammation in COPD suggest that targeted treatments with biologics may be a possibility COPD.
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Contaminación del Aire , Productos Biológicos , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Progresión de la Enfermedad , Inflamación/complicaciones , Productos Biológicos/uso terapéuticoRESUMEN
Rationale: Chronic obstructive pulmonary disease (COPD) exacerbations are a major cause of morbidity and mortality, and preventing them is a key treatment target. Long-term macrolide treatment is effective at reducing exacerbations, but there is a paucity of evidence for other antibiotic classes. Objectives: To assess whether 12-month use of doxycycline reduces the exacerbation rate in people with COPD. Methods: People with moderate to very severe COPD and an exacerbation history were recruited from three UK centers and randomized to 12 months of doxycycline 100 mg once daily or placebo. The primary study outcome was the exacerbation rate per person-year. Results: A total of 222 people were randomized. Baseline mean FEV1 was 1.35 L (SD, 0.35 L), 52.5% predicted (SD, 15.9% predicted). The median number of treated exacerbations in the year before the study was 2 (SD, 1-4). A total of 71% of patients reported two or more exacerbations, and 81% were already prescribed inhaled corticosteroids at baseline. The COPD exacerbation rate did not differ between the groups (doxycycline/placebo rate ratio [RR], 0.86; 95% confidence interval [CI], 0.67-1.10; P = 0.23). No difference was seen if only treated exacerbations or hospitalizations were considered. In preplanned subgroup analysis, doxycycline appeared to better reduce the exacerbation rate among people with severe COPD (RR, 0.36; 95% CI, 0.15-0.85; P = 0.019) and in those with an eosinophil count <300 cells/µl (RR, 0.50; 95% CI, 0.29-0.84; P = 0.01). Health status measured by St. George's Respiratory Questionnaire was 5.2 points worse in the doxycycline group at 12 months (P < 0.007). Conclusions: Doxycycline did not significantly reduce the exacerbation rate, over 12 months, in participants with COPD who exacerbated regularly, but it may have benefitted those with more severe COPD or blood eosinophil counts <300 cells/µl. Clinical trial registered with www.clinicaltrials.gov (NCT02305940).
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Doxiciclina , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Doxiciclina/uso terapéutico , Antibacterianos/uso terapéutico , Eosinófilos , Corticoesteroides/uso terapéutico , Método Doble Ciego , Progresión de la EnfermedadRESUMEN
Problematic fossils, extinct taxa of enigmatic morphology that cannot be assigned to a known major group, were once a major issue in palaeontology. A long-favoured solution to the 'problem of the problematica', particularly the 'weird wonders' of the Cambrian Burgess Shale, was to consider them representatives of extinct phyla. A combination of new evidence and modern approaches to phylogenetic analysis has now resolved the affinities of most of these forms. Perhaps the most notable exception is Tullimonstrum gregarium, popularly known as the Tully monster, a large soft-bodied organism from the late Carboniferous Mazon Creek biota (approximately 309-307 million years ago) of Illinois, USA, which was designated the official state fossil of Illinois in 1989. Its phylogenetic position has remained uncertain and it has been compared with nemerteans, polychaetes, gastropods, conodonts, and the stem arthropod Opabinia. Here we review the morphology of Tullimonstrum based on an analysis of more than 1,200 specimens. We find that the anterior proboscis ends in a buccal apparatus containing teeth, the eyes project laterally on a long rigid bar, and the elongate segmented body bears a caudal fin with dorsal and ventral lobes. We describe new evidence for a notochord, cartilaginous arcualia, gill pouches, articulations within the proboscis, and multiple tooth rows adjacent to the mouth. This combination of characters, supported by phylogenetic analysis, identifies Tullimonstrum as a vertebrate, and places it on the stem lineage to lampreys (Petromyzontida). In addition to increasing the known morphological disparity of extinct lampreys, a chordate affinity for T. gregarium resolves the nature of a soft-bodied fossil which has been debated for more than 50 years.
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Fósiles , Filogenia , Vertebrados/clasificación , Aletas de Animales/anatomía & histología , Animales , Extinción Biológica , Ojo/anatomía & histología , Tracto Gastrointestinal/anatomía & histología , Illinois , Lampreas/clasificación , Notocorda/anatomía & histología , Diente/anatomía & histología , Vertebrados/anatomía & histologíaRESUMEN
BACKGROUND: The mechanisms underlying altered susceptibility and propensity to severe Coronavirus disease 2019 (COVID-19) disease in at-risk groups such as patients with chronic obstructive pulmonary disease (COPD) are poorly understood. Inhaled corticosteroids (ICSs) are widely used in COPD, but the extent to which these therapies protect or expose patients to risk of severe COVID-19 is unknown. OBJECTIVE: The aim of this study was to evaluate the effect of ICSs following pulmonary expression of the SARS-CoV-2 viral entry receptor angiotensin-converting enzyme-2 (ACE2). METHODS: We evaluated the effect of ICS administration on pulmonary ACE2 expression in vitro in human airway epithelial cell cultures and in vivo in mouse models of ICS administration. Mice deficient in the type I IFN-α/ß receptor (Ifnar1-/-) and administration of exogenous IFN-ß were used to study the functional role of type-I interferon signaling in ACE2 expression. We compared sputum ACE2 expression in patients with COPD stratified according to use or nonuse of ICS. RESULTS: ICS administration attenuated ACE2 expression in mice, an effect that was reversed by exogenous IFN-ß administration, and Ifnar1-/- mice had reduced ACE2 expression, indicating that type I interferon contributes mechanistically to this effect. ICS administration attenuated expression of ACE2 in airway epithelial cell cultures from patients with COPD and in mice with elastase-induced COPD-like changes. Compared with ICS nonusers, patients with COPD who were taking ICSs also had reduced sputum expression of ACE2. CONCLUSION: ICS therapies in COPD reduce expression of the SARS-CoV-2 entry receptor ACE2. This effect may thus contribute to altered susceptibility to COVID-19 in patients with COPD.
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Corticoesteroides/administración & dosificación , Enzima Convertidora de Angiotensina 2/antagonistas & inhibidores , COVID-19 , Interferón Tipo I/antagonistas & inhibidores , Enfermedad Pulmonar Obstructiva Crónica/inmunología , SARS-CoV-2 , Administración por Inhalación , Anciano , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/inmunología , Animales , Bronquios/citología , Células Cultivadas , Susceptibilidad a Enfermedades , Regulación hacia Abajo/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/inmunología , Femenino , Humanos , Interferón Tipo I/inmunología , Pulmón/efectos de los fármacos , Pulmón/inmunología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/genética , Receptor de Interferón alfa y beta/genética , Serina Endopeptidasas/genéticaRESUMEN
Despite advances in the pathophysiology of chronic obstructive pulmonary disease (COPD), there is a distinct lack of biochemical markers to aid clinical management. Microvesicles (MVs) have been implicated in the pathophysiology of inflammatory diseases including COPD, but their association to COPD disease severity remains unknown. We analyzed different MV populations in plasma and bronchoalveolar lavage fluid (BALF) taken from 62 patients with mild to very severe COPD (51% male; mean age: 65.9 yr). These patients underwent comprehensive clinical evaluation (symptom scores, lung function, and exercise testing), and the capacity of MVs to be clinical markers of disease severity was assessed. We successfully identified various MV subtype populations within BALF [leukocyte, polymorphonuclear leukocyte (PMN; i.e., neutrophil), monocyte, epithelial, and platelet MVs] and plasma (leukocyte, PMN, monocyte, and endothelial MVs) and compared each MV population to disease severity. BALF neutrophil MVs were the only population to significantly correlate with the clinical evaluation scores including forced expiratory volume in 1 s, modified Medical Research Council dyspnea score, 6-min walk test, hyperinflation, and gas transfer. BALF neutrophil MVs, but not neutrophil cell numbers, also strongly correlated with BODE index. We have undertaken, for the first time, a comprehensive evaluation of MV profiles within BALF/plasma of COPD patients. We demonstrate that BALF levels of neutrophil-derived MVs are unique in correlating with a number of key functional and clinically relevant disease severity indexes. Our results show the potential of BALF neutrophil MVs for a COPD biomarker that tightly links a key pathophysiological mechanism of COPD (intra-alveolar neutrophil activation) with clinical severity/outcome.
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Líquido del Lavado Bronquioalveolar/química , Micropartículas Derivadas de Células/patología , Neutrófilos/patología , Alveolos Pulmonares/patología , Enfermedad Pulmonar Obstructiva Crónica/patología , Índice de Severidad de la Enfermedad , Anciano , Micropartículas Derivadas de Células/metabolismo , Citocinas/metabolismo , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Neutrófilos/metabolismo , Alveolos Pulmonares/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/etiología , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Pruebas de Función RespiratoriaRESUMEN
Rationale: Chronic obstructive pulmonary disease (COPD) exacerbations are prone to nonrecovery, but there are no data about the effectiveness of retreatment for these prolonged events. We examined whether further therapy with ciprofloxacin for incompletely resolved COPD exacerbations prolonged the time until the next event.Objectives: To assess whether incompletely recovered COPD exacerbations benefit from additional treatment with ciprofloxacin, at Day 14.Methods: In a multicenter, randomized double-blind placebo-controlled trial, we studied retreatment with oral ciprofloxacin 500 mg or matched placebo twice daily for 7 days in patients with Global Initiative for Chronic Obstructive Lung Disease stage II-IV COPD and persistent symptoms and/or serum C-reactive protein ≥8 mg/L initiated 14 (±3) days after an index COPD exacerbation. The primary outcome was the time to the next exacerbation within a 90-day period.Measurements and Main Results: Among 826 patients screened at four centers, 144 eligible participants with incomplete recovery were randomized to receive ciprofloxacin (n = 72) or placebo (n = 72). Within 90 days of randomization, 57% of the patients in the ciprofloxacin group and 53% in the placebo group experienced one or more exacerbations. The median time to the next exacerbation was 32.5 days (interquartile range 13-50) in the placebo arm and 34 days (interquartile range 17-62) in the ciprofloxacin arm, which was not significantly different (adjusted hazard ratio, 1.07; 95% confidence interval, 0.68-1.68; P = 0.76). No significant differences were seen in quality-of-life scores or lung function between the treatment groups.Conclusions: In patients with persistent symptoms and/or raised C-reactive protein 14 days after a COPD exacerbation, an additional course of ciprofloxacin resulted in no additional benefit compared with placebo. This suggests that nonrecovered exacerbations are not driven by ongoing bacterial infection and may potentially be targeted with antiinflammatory therapy.Clinical trial registered with www.clinicaltrials.gov (NCT02300220).
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Ciprofloxacina/uso terapéutico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Anciano , Progresión de la Enfermedad , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Retratamiento , Factores de Tiempo , Resultado del TratamientoRESUMEN
Rationale: Human rhinovirus (HRV) is a common cause of chronic obstructive pulmonary disease (COPD) exacerbations. Secondary bacterial infection is associated with more severe symptoms and delayed recovery. Alveolar macrophages clear bacteria from the lung and maintain lung homeostasis through cytokine secretion. These processes are defective in COPD. The effect of HRV on macrophage function is unknown. Objectives: To investigate the effect of HRV on phagocytosis and cytokine response to bacteria by alveolar macrophages and monocyte-derived macrophages (MDM) in COPD and healthy control subjects. Methods: Alveolar macrophages were obtained by bronchoscopy and MDM by adherence. Macrophages were exposed to HRV16 (multiplicity of infection 5), polyinosinic:polycytidylic acid (poly I:C) 30 µg/ml, IFN-ß 10 µg/ml, IFN-γ 10 µg/ml, or medium control for 24 hours. Phagocytosis of fluorescently labeled Haemophilus influenzae or Streptococcus pneumoniae was assessed by fluorimetry. CXCL8 (IL-8), IL-6, TNF-α (tumor necrosis factor-α), and IL-10 release was measured by ELISA. Measurements and Main Results: HRV significantly impaired phagocytosis of H. influenzae by 23% in MDM (n = 37; P = 0.004) and 18% in alveolar macrophages (n = 20; P < 0.0001) in COPD. HRV also significantly reduced phagocytosis of S. pneumoniae by 33% in COPD MDM (n = 20; P = 0.0192). There was no effect in healthy control subjects. Phagocytosis of H. influenzae was also impaired by poly I:C but not IFN-ß or IFN-γ in COPD MDM. HRV significantly reduced cytokine responses to H. influenzae. The IL-10 response to H. influenzae was significantly impaired by poly I:C, IFN-ß, and IFN-γ in COPD cells. Conclusions: HRV impairs phagocytosis of bacteria in COPD, which may lead to an outgrowth of bacteria. HRV also impairs cytokine responses to bacteria via the TLR3/IFN pathway, which may prevent resolution of inflammation leading to prolonged exacerbations in COPD.
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Macrófagos Alveolares/inmunología , Macrófagos Alveolares/virología , Fagocitosis/inmunología , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/microbiología , Enfermedad Pulmonar Obstructiva Crónica/virología , Rhinovirus/patogenicidad , Femenino , Humanos , Inmunidad Innata , Londres , Masculino , Persona de Mediana EdadRESUMEN
Patients with frequent exacerbations represent a chronic obstructive pulmonary disease (COPD) subgroup requiring better treatment options. The aim of this study was to determine the innate immune mechanisms that underlie susceptibility to frequent exacerbations in COPD. We measured sputum expression of immune mediators and bacterial loads in samples from patients with COPD at stable state and during virus-associated exacerbations. In vitro immune responses to rhinovirus infection in differentiated primary bronchial epithelial cells (BECs) sampled from patients with COPD were additionally evaluated. Patients were stratified as frequent exacerbators (≥2 exacerbations in the preceding year) or infrequent exacerbators (<2 exacerbations in the preceding year) with comparisons made between these groups. Frequent exacerbators had reduced sputum cell mRNA expression of the antiviral immune mediators type I and III interferons and reduced interferon-stimulated gene (ISG) expression when clinically stable and during virus-associated exacerbation. A role for epithelial cell-intrinsic innate immune dysregulation was identified: induction of interferons and ISGs during in vitro rhinovirus (RV) infection was also impaired in differentiated BECs from frequent exacerbators. Frequent exacerbators additionally had increased sputum bacterial loads at 2 wk following virus-associated exacerbation onset. These data implicate deficient airway innate immunity involving epithelial cells in the increased propensity to exacerbations observed in some patients with COPD. Therapeutic approaches to boost innate antimicrobial immunity in the lung could be a viable strategy for prevention and treatment of frequent exacerbations.
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Bronquios/inmunología , Inmunidad Innata/inmunología , Infecciones por Picornaviridae/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/inmunología , Insuficiencia Respiratoria/complicaciones , Rhinovirus/inmunología , Esputo/inmunología , Anciano , Bronquios/patología , Bronquios/virología , Progresión de la Enfermedad , Femenino , Volumen Espiratorio Forzado , Humanos , Estudios Longitudinales , Mediciones del Volumen Pulmonar , Masculino , Persona de Mediana Edad , Fenotipo , Infecciones por Picornaviridae/inmunología , Infecciones por Picornaviridae/virología , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/patología , Enfermedad Pulmonar Obstructiva Crónica/virología , Esputo/virologíaRESUMEN
Iron (Fe) is an essential micronutrient for symbiotic nitrogen fixation in legume nodules, where it is required for the activity of bacterial nitrogenase, plant leghemoglobin, respiratory oxidases, and other Fe proteins in both organisms. Fe solubility and transport within and between plant tissues is facilitated by organic chelators, such as nicotianamine and citrate. We have characterized a nodule-specific citrate transporter of the multidrug and toxic compound extrusion family, MtMATE67 of Medicago truncatula The MtMATE67 gene was induced early during nodule development and expressed primarily in the invasion zone of mature nodules. The MtMATE67 protein was localized to the plasma membrane of nodule cells and also the symbiosome membrane surrounding bacteroids in infected cells. In oocytes, MtMATE67 transported citrate out of cells in an Fe-activated manner. Loss of MtMATE67 gene function resulted in accumulation of Fe in the apoplasm of nodule cells and a substantial decrease in symbiotic nitrogen fixation and plant growth. Taken together, the results point to a primary role of MtMATE67 in citrate efflux from nodule cells in response to an Fe signal. This efflux is necessary to ensure Fe(III) solubility and mobility in the apoplasm and uptake into nodule cells. Likewise, MtMATE67-mediated citrate transport into the symbiosome space would increase the solubility and availability of Fe(III) for rhizobial bacteroids.
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Hierro/metabolismo , Medicago truncatula/fisiología , Fijación del Nitrógeno/fisiología , Proteínas de Plantas/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Citratos/metabolismo , Regulación de la Expresión Génica de las Plantas , Hierro/farmacocinética , Medicago truncatula/microbiología , Mutación , Filogenia , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Nódulos de las Raíces de las Plantas/crecimiento & desarrollo , Nódulos de las Raíces de las Plantas/metabolismo , Nódulos de las Raíces de las Plantas/microbiología , Simbiosis/fisiologíaRESUMEN
BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) have increased susceptibility to respiratory tract infection, which contributes to disease progression and mortality, but mechanisms of increased susceptibility to infection remain unclear. OBJECTIVES: The aim of this study was to determine whether glucose concentrations were increased in airway samples (nasal lavage fluid, sputum, and bronchoalveolar lavage fluid) from patients with stable COPD and to determine the effects of viral infection on sputum glucose concentrations and how airway glucose concentrations relate to bacterial infection. METHODS: We measured glucose concentrations in airway samples collected from patients with stable COPD and smokers and nonsmokers with normal lung function. Glucose concentrations were measured in patients with experimentally induced COPD exacerbations, and these results were validated in patients with naturally acquired COPD exacerbations. Relationships between sputum glucose concentrations, inflammatory markers, and bacterial load were examined. RESULTS: Sputum glucose concentrations were significantly higher in patients with stable COPD compared with those in control subjects without COPD. In both experimental virus-induced and naturally acquired COPD exacerbations, sputum and nasal lavage fluid glucose concentrations were increased over baseline values. There were significant correlations between sputum glucose concentrations and sputum inflammatory markers, viral load, and bacterial load. Airway samples with higher glucose concentrations supported more Pseudomonas aeruginosa growth in vitro. CONCLUSIONS: Airway glucose concentrations are increased in patients with stable COPD and further increased during COPD exacerbations. Increased airway glucose concentrations might contribute to bacterial infections in both patients with stable and those with exacerbated COPD. This has important implications for the development of nonantibiotic therapeutic strategies for the prevention or treatment of bacterial infection in patients with COPD.
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Glucosa/metabolismo , Infecciones por Pseudomonas/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Infecciones del Sistema Respiratorio/metabolismo , Anciano , Carga Bacteriana , Líquido del Lavado Bronquioalveolar/química , Femenino , Humanos , Masculino , Persona de Mediana Edad , Líquido del Lavado Nasal/química , Infecciones por Picornaviridae/metabolismo , Infecciones por Picornaviridae/microbiología , Infecciones por Pseudomonas/microbiología , Enfermedad Pulmonar Obstructiva Crónica/microbiología , Sistema Respiratorio/metabolismo , Sistema Respiratorio/microbiología , Infecciones del Sistema Respiratorio/microbiología , Fumar/metabolismo , Esputo/metabolismo , Carga ViralRESUMEN
Trace metals play important roles in biological function, and x-ray fluorescence microscopy (XFM) provides a way to quantitatively image their distribution within cells. The faithfulness of these measurements is dependent on proper sample preparation. Using mouse embryonic fibroblast NIH/3T3 cells as an example, we compare various approaches to the preparation of adherent mammalian cells for XFM imaging under ambient temperature. Direct side-by-side comparison shows that plunge-freezing-based cryoimmobilization provides more faithful preservation than conventional chemical fixation for most biologically important elements including P, S, Cl, K, Fe, Cu, Zn and possibly Ca in adherent mammalian cells. Although cells rinsed with fresh media had a great deal of extracellular background signal for Cl and Ca, this approach maintained cells at the best possible physiological status before rapid freezing and it does not interfere with XFM analysis of other elements. If chemical fixation has to be chosen, the combination of 3% paraformaldehyde and 1.5 % glutaraldehyde preserves S, Fe, Cu and Zn better than either fixative alone. When chemically fixed cells were subjected to a variety of dehydration processes, air drying was proved to be more suitable than other drying methods such as graded ethanol dehydration and freeze drying. This first detailed comparison for x-ray fluorescence microscopy shows how detailed quantitative conclusions can be affected by the choice of cell preparation method.
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Fibroblastos/química , Fibroblastos/citología , Microscopía Fluorescente/métodos , Espectrometría por Rayos X/métodos , Fijación del Tejido/métodos , Oligoelementos/análisis , Animales , Ratones , Células 3T3 NIHRESUMEN
The placenta is the organ that mediates transport of nutrients and waste materials between mother and fetus. Synchrotron X-ray fluorescence (SXRF) microanalysis is a tool for imaging the distribution and quantity of elements in biological tissue, which can be used to study metal transport across biological membranes. Our aims were to pilot placental biopsy specimen preparation techniques that could be integrated into an ongoing epidemiology birth cohort study without harming rates of sample acquisition. We studied the effects of fixative (formalin or glutaraldehyde) and storage duration (30 days or immediate processing) on metal distribution and abundance and investigated a thaw-fixation protocol for archived specimens stored at -80 °C. We measured fixative elemental composition with and without a placental biopsy via inductively coupled plasma mass spectrometry (ICP-MS) to quantify fixative-induced elemental changes. Formalin-fixed specimens showed hemolysis of erythrocytes. The glutaraldehyde-paraformaldehyde solution in HEPES buffer (GTA-HEPES) had superior anatomical preservation, avoided hemolysis, and minimized elemental loss, although some cross-linking of exogenous Zn was evident. Elemental loss from tissue stored in fixative for 1 month showed variable losses (≈40 % with GTA-HEPES), suggesting storage duration be controlled for. Thawing of tissue held at -80 °C in a GTA-HEPES solution provided high-quality visual images and elemental images.
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Vellosidades Coriónicas/química , Metales/análisis , Espectrometría por Rayos X/métodos , Sincrotrones , Femenino , Humanos , Masculino , Embarazo , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrometría por Rayos X/instrumentaciónRESUMEN
The micro-focusing performance for hard X-rays of a fixed-geometry elliptical Kirkpatrick-Baez (K-B) mirrors assembly fabricated, tested and finally implemented at the micro-probe beamline 8-BM of the Advanced Photon Source is reported. Testing of the K-B mirror system was performed at the optics and detector test beamline 1-BM. K-B mirrors of length 80â mm and 60â mm were fabricated by profile coating with Pt metal to produce focal lengths of 250â mm and 155â mm for 3â mrad incident angle. For the critical angle of Pt, a broad bandwidth of energies up to 20â keV applies. The classical K-B sequential mirror geometry was used, and mirrors were mounted on micro-translation stages. The beam intensity profiles were measured by differentiating the curves of intensity data measured using a wire-scanning method. A beam size of 1.3â µm (V) and 1.2â µm (H) was measured with monochromatic X-rays of 18â keV at 1-BM. After installation at 8-BM the measured focus met the design requirements. In this paper the fabrication and metrology of the K-B mirrors are reported, as well as the focusing performances of the full mirrors-plus-mount set-up at both beamlines.
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Metals are essential cofactors, utilized in many critical cellular processes. For example, zinc is important in insulin biosynthesis and may play a role in Alzheimer's disease, but much of how the zinc-mediated process remains unknown. Knowing which metal is in which protein at a given point in time would lead to new insights into how metals work in biological systems. New tools are being developed to investigate the biochemistry and cell biology of metals, with potential for biomedical applications. In this report, we consider the promise and limitations of metalloproteins detection techniques. We provide a brief overview of the techniques available and a discussion of the technical challenges to biomedical applications, with particular focus on what must be overcome for the potential of these approaches to be achieved.
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Metaloproteínas/metabolismo , Proteoma/metabolismo , Proteómica/métodos , Investigación Biomédica/tendencias , Complejos de Coordinación/metabolismo , Humanos , Proteómica/tendencias , Zinc/metabolismoRESUMEN
Dynamic fluxes of s-block metals like potassium, sodium, and calcium are of broad importance in cell signaling. In contrast, the concept of mobile transition metals triggered by cell activation remains insufficiently explored, in large part because metals like copper and iron are typically studied as static cellular nutrients and there are a lack of direct, selective methods for monitoring their distributions in living cells. To help meet this need, we now report Coppersensor-3 (CS3), a bright small-molecule fluorescent probe that offers the unique capability to image labile copper pools in living cells at endogenous, basal levels. We use this chemical tool in conjunction with synchotron-based microprobe X-ray fluorescence microscopy (XRFM) to discover that neuronal cells move significant pools of copper from their cell bodies to peripheral processes upon their activation. Moreover, further CS3 and XRFM imaging experiments show that these dynamic copper redistributions are dependent on calcium release, establishing a link between mobile copper and major cell signaling pathways. By providing a small-molecule fluorophore that is selective and sensitive enough to image labile copper pools in living cells under basal conditions, CS3 opens opportunities for discovering and elucidating functions of copper in living systems.
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Compuestos de Boro/química , Calcio/metabolismo , Cobre/análisis , Colorantes Fluorescentes/química , Neuronas/metabolismo , Sulfuros/química , Animales , Compuestos de Boro/síntesis química , Células Cultivadas , Cobre/metabolismo , Colorantes Fluorescentes/síntesis química , Células HEK293 , Humanos , Microscopía Fluorescente/métodos , Ratas , Espectrometría por Rayos X/métodos , Sulfuros/síntesis químicaRESUMEN
The chronic exposure of humans to the toxic metal cadmium (Cd), either occupational or from food and air, causes various diseases, including neurodegenerative conditions, dysfunction of vital organs, and cancer. While the toxicology of Cd and its effect on the homeostasis of biologically relevant elements is increasingly recognized, the spatial distribution of Cd and other elements in Cd toxicity-caused diseases is still poorly understood. Here, we use Caenorhabditis elegans as a non-mammalian multicellular model system to determine the distribution of Cd at the tissue and cellular resolution and its effect on the internal levels and the distribution of biologically relevant elements. Using inductively coupled plasma-mass spectrophotometry (ICP-MS), we show that exposure of worms to Cd not only led to its internal accumulation but also significantly altered the C. elegans ionome. Specifically, Cd treatment was associated with increased levels of toxic elements such as arsenic (As) and rubidium (Rb) and a decreased accumulation of essential elements such as zinc (Zn), copper (Cu), manganese (Mn), calcium (Ca), cobalt (Co) and, depending on the Cd-concentration used in the assay, iron (Fe). We regarded these changes as an ionomic signature of Cd toxicity in C. elegans. We also show that supplementing nematode growth medium with Zn but not Cu, rescues Cd toxicity and that mutant worms lacking Zn transporters CDF-1 or SUR-7, or both are more sensitive to Cd toxicity. Finally, using synchrotron X-Ray fluorescence Microscopy (XRF), we showed that Cd significantly alters the spatial distribution of mineral elements. The effect of Cd on the distribution of Fe was particularly striking: while Fe was evenly distributed in intestinal cells of worms grown without Cd, in the presence of Cd, Fe, and Cd co-localized in punctum-like structures in the intestinal cells. Together, this study advances our understanding of the effect of Cd on the accumulation and distribution of biologically relevant elements. Considering that C. elegans possesses the principal tissues and cell types as humans, our data may have important implications for future therapeutic developments aiming to alleviate Cd-related pathologies in humans.
RESUMEN
Background: Early and accurate identification of acute exacerbations of COPD may lead to earlier treatment and prevent hospital admission. Electronic diaries have been developed for symptom monitoring and accelerometers to monitor activity. However, it is unclear whether this technology is usable in the COPD population. This study aimed to assess the feasibility of an electronic diary (eDiary) for symptom reporting using the MoreCare app and activity monitoring with the Garmin Vivofit 2 in COPD. Methods: Participants were recruited from the London COPD Cohort. Participants were provided a Garmin Vivofit 2 activity monitor and an android tablet with the MoreCare app for a period of 3â months. Results: 25 COPD patients were recruited (mean±sd age 70.8±7.1â years, forced expiratory volume in 1â s (FEV1) 49.8±14.8% predicted). Age, gender, disease severity and exacerbation frequency had no impact on eDiary compliance. There was a moderate positive correlation between median daily very active minutes and FEV1 % pred (ρ=0.62, p=0.005). Daily step counts decreased during the initial 7â days of exacerbation and recovery compared to a pre-exacerbation baseline. A decision-tree model identified change in sputum colour, change in step count, severity of cold, exacerbation history and use of rescue medication as the most important predictors of acute exacerbations of COPD in this cohort. Conclusions: Symptom and activity monitoring using digital technology is feasible in COPD. Further large-scale digital health studies are needed to assess whether eDiaries can be used to identify patients at risk of exacerbation and guide early intervention.