171 research outputs found

    Supervivencia de una pequeña población trasladada de Procolobus kirkii en la isla de Pemba

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    A survey to evaluate the distribution of Procolobus kirkii on Pemba island (Tanzania) was conducted, 20 years after they had been translocated from Zanzibar in the Ngezi forest park. A team of both expert and trained observers, guided by the authors, censused 68.3 linear km of forest, corresponding to an estimated area of 3.5 km2 (63.6%) of the protected Ngezi forested area of 5.5 km2. Nineteen groups of Cercopithecus aethiops were observed, with a total of 166 animals and an estimated density of 47.43 individuals per km2, and only one troop of Procolobus kirkii. Supplemented by interviewing the local people we obtained an estimate of 15–30 P. kirkii, including a small troop outside the protected area. This small population survived but did not increase, possibly due to adverse relations with humans.Se realizó un estudio para evaluar la distribución de Procolobus kirkii en la isla de Pemba (Tanzania), veinte años después de que fuera trasladada desde Zanzíbar al Parque Ngezi. Un equipo de observadores expertos y entrenados, guiados por los autores, efectuó un censo a lo largo de 68,3 km lineales de bosque, correspondiente a un área estimada de 3,5 km2 (63,6%) del área protegida del bosque de Ngezi de 5,5 km2. Se observaron 19 grupos de Cercopithecus aethiops, con un total de 166 animales y una densidad estimada de 47,43 individuos/km2, y sólo un grupo de Procolobus kirkii. Complementando los datos con entrevistas a la población local se obtuvo una estimación de 15–30 ejemplares de P. kirkii, incluyendo un pequeño grupo localizado fuera del área protegida. Este pequeño grupo sobrevivía pero no se incrementaba en número, posiblemente debido a las relaciones adversas con los humanos

    Survival of a small translocated Procolobus kirkii population on Pemba Island

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    A survey to evaluate the distribution of Procolobus kirkii on Pemba island (Tanzania) was conducted, 20 years after they had been translocated from Zanzibar in the Ngezi forest park. A team of both expert and trained observers, guided by the authors, censused 68.3 linear km of forest, corresponding to an estimated area of 3.5 km2 (63.6%) of the protected Ngezi forested area of 5.5 km2. Nineteen groups of Cercopithecus aethiops were observed, with a total of 166 animals and an estimated density of 47.43 individuals per km2, and only one troop of Procolobus kirkii. Supplemented by interviewing the local people we obtained an estimate of 15-30 P. kirkii, including a small troop outside the protected area. This small population survived but did not increase, possibly due to adverse relations with humans

    Evolution of airway inflammation in preschoolers with asthma : results of a two-year longitudinal study

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    Fractional exhaled nitric oxide (FeNO) is a non-invasive marker for eosinophilic airway inflammation and has been used for monitoring asthma. Here, we assess the characteristics of FeNO from preschool to school age, in parallel with asthma activity. A total of 167 asthmatic children and 66 healthy, age-matched controls were included in the 2-year prospective PreDicta study evaluating wheeze/asthma persistence in preschool-aged children. Information on asthma/rhinitis activity, infections and atopy was recorded at baseline. Follow-up visits were performed at 6-month intervals, as well as upon exacerbation/cold and 4-6 weeks later in the asthmatic group. We obtained 539 FeNO measurements from asthmatics and 42 from controls. At baseline, FeNO values did not differ between the two groups (median: 3.0 ppb vs. 2.0 ppb, respectively). FeNO values at 6, 12, 18 and 24 months (4.0, CI: 0.0-8.6; 6.0, CI: 2.8-12.0; 8.0, CI: 4.0-14.0; 8.5, CI: 4.4-14.5 ppb, respectively) increased with age (correlation p <= 0.001) and atopy (p = 0.03). FeNO was non-significantly increased from baseline to the symptomatic visit, while it decreased after convalescence (p = 0.007). Markers of disease activity, such as wheezing episodes and days with asthma were associated with increased FeNO values during the study (p < 0.05 for all). Age, atopy and disease activity were found to be important FeNO determinants in preschool children. Longitudinal and individualized FeNO assessment may be valuable in monitoring asthmatic children with recurrent wheezing or mild asthma

    Clinical correlates of rhinovirus infection in preschool asthma

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    Background Investigation of preschool asthma is important since not all children outgrow their illness during this age. Data are scarce on the role of rhinovirus (RV) infections in this patient group. Objectives To investigate the role of RV infections in preschool asthma: (i) susceptibility factors, (ii) clinical course, and (iii) medium-term outcome. Methods A total of 130 asthmatic children aged 4-6 years from the multinational PreDicta cohort were prospectively followed for a 12-month period. Allergy tests and a standard health questionnaire were carried out at study entry. Respiratory virus presence in nasopharyngeal washes was studied at illness visits and at 3 scheduled visits. Results At study entry, mean age of the children was 5.3 years. Of 571 visits, 54% were positive for any virus and 39% for RV. Patient characteristics were only assessed with RV infection due to low number of other viruses. The use of supplementary vitamin D was inversely associated with RV infection (P < .05). RV infection was associated with more severe course of acute illness in terms of more severe nighttime coughing, more sleep disturbances, and more days with runny nose (allP < .05). RV infection was also associated with more severe disease course during the 12-month follow-up in terms of more nights with awakenings and more days of exercise-related symptoms (bothP < .05). Conclusions Vitamin D supplementation may have an anti-rhinovirus effect. Both short- and medium-term outcomes suggest RV infection to be an important clinical marker of instable preschool asthma

    Respiratory eukaryotic virome expansion and bacteriophage deficiency characterize childhood asthma

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    Asthma development and exacerbation is linked to respiratory virus infections. There is limited information regarding the presence of viruses during non-exacerbation/infection periods. We investigated the nasopharyngeal/nasal virome during a period of asymptomatic state, in a subset of 21 healthy and 35 asthmatic preschool children from the Predicta cohort. Using metagenomics, we described the virome ecology and the cross-species interactions within the microbiome. The virome was dominated by eukaryotic viruses, while prokaryotic viruses (bacteriophages) were independently observed with low abundance. Rhinovirus B species consistently dominated the virome in asthma. Anelloviridae were the most abundant and rich family in both health and asthma. However, their richness and alpha diversity were increased in asthma, along with the co-occurrence of different Anellovirus genera. Bacteriophages were richer and more diverse in healthy individuals. Unsupervised clustering identified three virome profiles that were correlated to asthma severity and control and were independent of treatment, suggesting a link between the respiratory virome and asthma. Finally, we observed different cross-species ecological associations in the healthy versus the asthmatic virus-bacterial interactome, and an expanded interactome of eukaryotic viruses in asthma. Upper respiratory virome "dysbiosis" appears to be a novel feature of pre-school asthma during asymptomatic/non-infectious states and merits further investigation

    PU.1 controls fibroblast polarization and tissue fibrosis

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    Fibroblasts are polymorphic cells with pleiotropic roles in organ morphogenesis, tissue homeostasis and immune responses. In fibrotic diseases, fibroblasts synthesize abundant amounts of extracellular matrix, which induces scarring and organ failure. By contrast, a hallmark feature of fibroblasts in arthritis is degradation of the extracellular matrix because of the release of metalloproteinases and degrading enzymes, and subsequent tissue destruction. The mechanisms that drive these functionally opposing pro-fibrotic and pro-inflammatory phenotypes of fibroblasts remain unknown. Here we identify the transcription factor PU.1 as an essential regulator of the pro-fibrotic gene expression program. The interplay between transcriptional and post-transcriptional mechanisms that normally control the expression of PU.1 expression is perturbed in various fibrotic diseases, resulting in the upregulation of PU.1, induction of fibrosis-associated gene sets and a phenotypic switch in extracellular matrix-producing pro-fibrotic fibroblasts. By contrast, pharmacological and genetic inactivation of PU.1 disrupts the fibrotic network and enables reprogramming of fibrotic fibroblasts into resting fibroblasts, leading to regression of fibrosis in several organs

    Svep1 stabilizes developmental vascular anastomosis in reduced flow conditions

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    We report the discovery that flow and Svep1 are modulator of vessel anastomosis during developmental angiogenesis in zebrafish embryos. We show that loss of Svep1 and blood flow reduction both contribute to defective anastomosis of intersegmental vessels. We show that this defect in primary angiogenic sprouts is associated with an expansion of Apelin-positive tip cells and with reduced formation and lumenisation of the dorsal longitudinal anastomotic vessel. Mechanistically, our results suggest that flow and Svep1 act synergistically to modulate vascular network formation in the zebrafish trunk

    Effects of intranasal TNFα on granulocyte recruitment and activity in healthy subjects and patients with allergic rhinitis

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    <p>Abstract</p> <p>Background</p> <p>TNFα may contribute to the pathophysiology of airway inflammation. For example, we have recently shown that nasal administration of TNFα produces late phase co-appearance of granulocyte and plasma exudation markers on the mucosal surface. The objective of the present study was to examine indices of granulocyte presence and activity in response to intranasal TNFα challenge.</p> <p>Methods</p> <p>Healthy subjects and patients with allergic rhinitis (examined out of season) were subjected to nasal challenge with TNFα (10 μg) in a sham-controlled and crossover design. Nasal lavages were carried out prior to and 24 hours post challenge. Nasal biopsies were obtained post challenge. Nasal lavage fluid levels of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) were analyzed as indices of neutrophil and eosinophil activity. Moreover, IL-8 and α<sub>2</sub>-macroglobulin were analyzed as markers of pro-inflammatory cytokine production and plasma exudation. Nasal biopsy numbers of neutrophils and eosinophils were monitored.</p> <p>Results</p> <p>Nasal lavage fluid levels of MPO recorded 24 hours post TNFα challenge were increased in healthy subjects (p = 0.0081) and in patients with allergic rhinitis (p = 0.0081) (<it>c.f</it>. sham challenge). Similarly, α<sub>2</sub>-macroglobulin was increased in healthy subjects (p = 0.014) and in patients with allergic rhinitis (p = 0.0034). Lavage fluid levels of ECP and IL-8 were not affected by TNFα challenge. TNFα increased the numbers of subepithelial neutrophils (p = 0.0021), but not the numbers of eosinophils.</p> <p>Conclusion</p> <p>TNFα produces a nasal inflammatory response in humans that is characterised by late phase (i.e., 24 hours post challenge) neutrophil activity and plasma exudation.</p

    Svep1 stabilises developmental vascular anastomosis in reduced flow conditions

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    Molecular mechanisms controlling the formation, stabilization and maintenance of blood vessel connections remain poorly defined. Here we identify blood flow and the large extracellular protein Svep1 as co-modulators of vessel anastomosis during developmental angiogenesis in zebrafish embryos. Both loss of Svep1 and blood flow reduction contribute to defective anastomosis of intersegmental vessels. The reduced formation and lumenisation of the dorsal longitudinal anastomotic vessel (DLAV) is associated with a compensatory increase in Vegfa/Vegfr pERK signalling, concomittant expansion of apelin-positive tip cells, but reduced expression of klf2. Experimentally, further increasing Vegfa/Vegfr signalling can rescue the DLAV formation and lumenisation defects, while its inhibition dramatically exacerbates the loss of connectivity. Mechanistically, our results suggest that flow and Svep1 co-regulate the stabilization of vascular connections, in part by modulating the Vegfa/Vegfr signalling pathway
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