2,290 research outputs found

    Arrested B Lymphopoiesis and Persistence of Activated B Cells in Adult Interleukin 7

    Get PDF
    This deposit is composed by a publication in which the IGC' authors have had the role of collaboration (it's a collaboration publication). This type of deposit in ARCA is in restrictedAccess (it can't be in open access to the public), and could only be accessed by two ways: either by requesting a legal copy to the author (the email contact present in this deposit) or by visiting the following link: https://f1000.com/prime/1003667Interleukin 7 is a crucial factor for the development of murine T and B lymphocytes. We now report that, in the absence of interleukin 7, B lymphocyte production takes place exclusively during fetal and perinatal life, ceasing after 7 wk of age. In peripheral organs, however, the pool of B lymphocytes is stable throughout adult life and consists only of cells that belong to the B1 and marginal zone (MZ) compartments. This is accompanied by a 50-fold increase in the frequency of immunoglobulin (Ig)M- and IgG-secreting cells, and the concentration of serum immunoglobulins is increased three- to fivefold. Both the MZ phenotype and the increase in serum IgM are T cell independent. These findings reveal a previously undescribed pathway of B lymphopoiesis that is active in early life and is interleukin 7 independent. This pathway generates B1 cells and a normal sized MZ B lymphocyte compartment

    Arrested B Lymphopoiesis and Persistence of Activated B Cells in Adult Interleukin 7−/− Mice

    Get PDF
    Interleukin 7 is a crucial factor for the development of murine T and B lymphocytes. We now report that, in the absence of interleukin 7, B lymphocyte production takes place exclusively during fetal and perinatal life, ceasing after 7 wk of age. In peripheral organs, however, the pool of B lymphocytes is stable throughout adult life and consists only of cells that belong to the B1 and marginal zone (MZ) compartments. This is accompanied by a 50-fold increase in the frequency of immunoglobulin (Ig)M- and IgG-secreting cells, and the concentration of serum immunoglobulins is increased three- to fivefold. Both the MZ phenotype and the increase in serum IgM are T cell independent. These findings reveal a previously undescribed pathway of B lymphopoiesis that is active in early life and is interleukin 7 independent. This pathway generates B1 cells and a normal sized MZ B lymphocyte compartment

    Morphologic analysis of developmental phases and gill ontogenesis in neotropical species Poecilia vivipara (Cyprinodontiformes: Poeciliidae) exposed to different salinities

    Get PDF
    The present study evaluated and characterized the different phases of development and the cell types present in the gill epithelium of embryos, larvae, and fingerlings of guppy (Poecilia vivipara Bloch & Schneider, 1801) specimens exposed to water with salinity ranging from 0 to 20 . The development of P. vivipara was classified into eight phases. The yolk was intensely eosinophilic, with glycidic and lipidic components between phases 1 to 7. After the development of their branchial epithelium, the presence of pavement cells, mitochondria-rich cells, and mucous cells (MCs) was observed. The understanding of ontogenesis indicates the sequence of cellular origin. Only type IV MCs located in the gill rays was detected from phase 3 through phase 7. Other types of MCs were observed only when the fingerlings were exposed to salinity changes and showed to be lectin-reactive, thus indicating that P. vivipara modulates the cellular behavior when submitted to salinity changes. Exposure to variable saline concentrations did not interfere in the initial development of guppies. The presence of a yolk sac until the fingerling phase characterized this species as ovoviviparous.55456

    Effect of Ischemic Preconditioning on the Recovery of Cardiac Autonomic Control From Repeated Sprint Exercise

    Get PDF
    Repeated sprint exercise (RSE) acutely impairs post-exercise heart rate (HR) recovery (HRR) and time-domain heart rate variability (i. e., RMSSD), likely in part, due to lactic acidosis-induced reduction of cardiac vagal reactivation. In contrast, ischemic preconditioning (IPC) mediates cardiac vagal activation and augments energy metabolism efficiency during prolonged ischemia followed by reperfusion. Therefore, we investigated whether IPC could improve recovery of cardiac autonomic control from RSE partially via improved energy metabolism responses to RSE. Fifteen men team-sport practitioners (mean ± SD: 25 ± 5 years) were randomly exposed to IPC in the legs (3 × 5 min at 220 mmHg) or control (CT; 3 × 5 min at 20 mmHg) 48 h, 24 h, and 35 min before performing 3 sets of 6 shuttle running sprints (15 + 15 m with 180° change of direction and 20 s of active recovery). Sets 1 and 2 were followed by 180 s and set 3 by 360 s of inactive recovery. Short-term HRR was analyzed after all sets via linear regression of HR decay within the first 30 s of recovery (T30) and delta from peak HR to 60 s of recovery (HRR60s). Long-term HRR was analyzed throughout recovery from set 3 via first-order exponential regression of HR decay. Moreover, RMSSD was calculated using 30-s data segments throughout recovery from set 3. Energy metabolism responses were inferred via peak pulmonary oxygen uptake (V˙O2peak), peak carbon dioxide output (V˙O2peak), peak respiratory exchange ratio (RERpeak), first-order exponential regression of V˙O2 decay within 360 s of recovery and blood lactate concentration ([Lac-]). IPC did not change T30, but increased HRR60s after all sets (condition main effect: P = 0.03; partial eta square (η2p) = 0.27, i.e., large effect size). IPC did not change long-term HRR and RMSSD throughout recovery, nor did IPC change any energy metabolism parameter. In conclusion, IPC accelerated to some extent the short-term recovery, but did not change the long-term recovery of cardiac autonomic control from RSE, and such accelerator effect was not accompanied by any IPC effect on surrogates of energy metabolism responses to RSE

    Using Grasses Morphogenetic Variables for Natural Grassland Grazing Management

    Get PDF
    In a perspective of ecologically sustainable agriculture, culturally accepted and economically feasible, natural pastures fits as one of the best options for Southern Brazil region. This study assessed the feasibility of rearing beef heifers from 12 to 18 months of age in natural pasture during its growing season (173 days). We evaluated two rest intervals in a natural pasture managed under rotational grazing. Intervals were defined based on the average thermal sum (degree-days) that fits to leaf expansion duration (average of two leaves) of native species of two grasses functional groups, according to Cruz et al. (2010). Only grasses were included in these groups considering their contribution above 65% of forage mass and also their ranking on two functional traits, specific leaf area and leaf dry matter content as reported by the above authors. One group was called resources’ capture functional group, favoring prostrate species with fast biomass accumulation (e.g. Axonopus affinis, Paspalum notatum) and the other resources’ conservation group, favoring tufted species efficient in conserving soil nutrients with higger standing biomass but lower accumulation rate (e.g. Aristida laevis, Saccharum angustifolium). The trial aims to incorporate a functional approach into management schedules for increasing grazing efficiency of natural grasslands production without losses in its biodiversity

    Methods of Ryegrass Establishment (\u3cem\u3eLolium multiflorum\u3c/em\u3e Lam.) Affecting Optimal Sward Height to Maximize the Intake Rate

    Get PDF
    In integrated systems it is common to use the no-tillage method. The adoption of this method improves the system\u27s sustainability (Laurent et al. 2011). It is necessary to understand the effects of the integrated systems on sward structure and its consequences in the grazing process and in animal production. The intake rate of grazing animals is primarily responsible for the animal performance (Coleman 2006), which short-termdepends mainly on sward structure (Laca and Demment 2006). The sward height has great influence on the animal decision on where to take the next bite (Mcgilloway et al. 1999). The hypothesis of this work was: is there an optimum sward height for ryegrass (Lolium multiflorum Lam.) to maximize the intake rate by grazing animals and does this height vary depending on the existence of the base layer of straw canopy

    Does early specialization provide an advantage in physical fitness development in youth basketball?

    Get PDF
    The present study examined the influence of the specialization onset on the magnitude and patterns of changes in basketball-specific physical fitness within a competitive season and developmental fitness trends between 11 and 17 years in young basketball players. Repeated measures of 181 young basketball players (female, n = 40; male, n = 141) were examined. Anthropometry, age, estimated maturity status, and basketball-specific physical fitness (assessed with the countermovement jump, line drill, and yo-yo intermittent recovery level-1 and fitness score) were considered. Players were grouped by the onset of specialization as related to biological maturation milestones (pre-puberty, mid-puberty, and late-puberty specialization). The within-season and developmental changes in physical fitness were fitted using multilevel modeling in a fully Bayesian framework. The fitness outcomes were similar between-player and within-player changes when grouped by specialization across a season. Fitness improvements across a season were apparent for female players, while male players maintained their performance levels. There was no variation in the patterns of physical fitness development between 11 and 17 years associated with the onset of specialization. Conditional on our data and models, the assumption that early sport specialization provides a physical fitness advantage for future athletic success does not hold

    A combined approach for comparative exoproteome analysis of Corynebacterium pseudotuberculosis

    Get PDF
    Background: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and goats. Results: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome. Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of most of the remaining proteins. Conclusions: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far
    • 

    corecore