Sudden cardiac death athletes: a systematic review

Previous events evidence that sudden cardiac death (SCD) in athletes is still a reality and it keeps challenging cardiologists. Considering the importance of SCD in athletes and the requisite for an update of this matter, we endeavored to describe SCD in athletes. The Medline (via PubMed) and SciELO databases were searched using the subject keywords "sudden death, athletes and mortality". The incidence of SCD is expected at one case for each 200,000 young athletes per year. Overall it is resulted of complex dealings of factors such as arrhythmogenic substrate, regulator and triggers factors. In great part of deaths caused by heart disease in athletes younger than 35 years old investigations evidence cardiac congenital abnormalities. Athletes above 35 years old possibly die due to impairments of coronary heart disease, frequently caused by atherosclerosis. Myocardial ischemia and myocardial infarction are responsible for the most cases of SCD above this age (80%). Pre-participatory athletes' evaluation helps to recognize situations that may put the athlete's life in risk including cardiovascular diseases. In summary, cardiologic examinations of athletes' pre-competition routine is an important way to minimize the risk of SCD

Prebiotic potential of a maize-based soluble fibre and impact of dose on the human gut microbiota

Dietary management of the human gut microbiota towards a more beneficial composition is one approach that may improve host health. To date, a large number of human intervention studies have demonstrated that dietary consumption of certain food products can result in significant changes in the composition of the gut microbiota i.e. the prebiotic concept. Thus the prebiotic effect is now established as a dietary approach to increase beneficial gut bacteria and it has been associated with modulation of health biomarkers and modulation of the immune system. Promitor™ Soluble Corn Fibre (SCF) is a well-known maize-derived source of dietary fibre with potential selective fermentation properties. Our aim was to determine the optimum prebiotic dose of tolerance, desired changes to microbiota and fermentation of SCF in healthy adult subjects. A double-blind, randomised, parallel study was completed where volunteers (n = 8/treatment group) consumed 8, 14 or 21 g from SCF (6, 12 and 18 g/fibre delivered respectively) over 14-d. Over the range of doses studied, SCF was well tolerated Numbers of bifidobacteria were significantly higher for the 6 g/fibre/day compared to 12g and 18g/fibre delivered/day (mean 9.25 and 9.73 Log10 cells/g fresh faeces in the pre-treatment and treatment periods respectively). Such a numerical change of 0.5 Log10 bifidobacteria/g fresh faeces is consistent with those changes observed for inulin-type fructans, which are recognised prebiotics. A possible prebiotic effect of SCF was therefore demonstrated by its stimulation of bifidobacteria numbers in the overall gut microbiota during a short-term intervention

Identification of Novel Mt-Guab2 Inhibitor Series Active against M. tuberculosis

Tuberculosis (TB) remains a leading cause of mortality worldwide. With the emergence of multidrug resistant TB, extensively drug resistant TB and HIV-associated TB it is imperative that new drug targets be identified. The potential of Mycobacterium tuberculosis inosine monophosphate dehydrogenase (IMPDH) as a novel drug target was explored in the present study. IMPDH exclusively catalyzes the conversion of inosine monophosphate (IMP) to xanthosine monophosphate (XMP) in the presence of the cofactor nicotinamide adenine dinucleotide (NAD+). Although the enzyme is a dehydrogenase, the enzyme does not catalyze the reverse reaction i.e. the conversion of XMP to IMP. Unlike other bacteria, M. tuberculosis harbors three IMPDH-like genes, designated as Mt-guaB1, Mt-guaB2 and Mt-guaB3 respectively. Of the three putative IMPDH's, we previously confirmed that Mt-GuaB2 was the only functional ortholog by characterizing the enzyme kinetically. Using an in silico approach based on designed scaffolds, a series of novel classes of inhibitors was identified. The inhibitors possess good activity against M. tuberculosis with MIC values in the range of 0.4 to 11.4 µg mL−1. Among the identified ligands, two inhibitors have nanomolar Kis against the Mt-GuaB2 enzyme

Local deformation in a hydrogel induced by an external magnetic field

The aim of this study is to prove the feasibility of a system able to apply local mechanical loading on cells seeded in a hydrogel for tissue engineering applications. This experimental study is based on a previously developed artificial cartilage model with different concentrations of poly(vinyl alcohol) (PVA) that simulates the cartilage extracellular matrix (ECM). Poly(l-lactic acid) (PLLA) microspheres with dispersed magnetic nanoparticles (MNPs) were produced with an emulsion method. These microspheres were embedded in aqueous PVA solutions with varying concentration to resemble increased viscosity of growing tissue during regeneration. The ability to induce a local deformation in the ECM was assessed by applying a steady or an oscillatory magnetic field gradient to different PVA solutions containing the magnetic microparticles, similarly as in ferrogels. PLLA microparticle motion was recorded, and the images were analyzed. Besides, PVA gels and PLLA microparticles were introduced into the pores of a polycaprolactone scaffold, and the microparticle distribution and the mechanical properties of the construct were evaluated. The results of this experimental model show that the dispersion of PLLA microparticles containing MNPs, together with cells in a supporting gel, will allow applying local mechanical stimuli to cells during tissue regeneration. This local stimulation can have a positive effect on the differentiation of seeded cells and improve tissue regeneration.The authors gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness through the MAT2013-46467-C4-1-R project, including the Feder funds. CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. 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The p75 neurotrophin receptor is expressed by adult mouse dentate progenitor cells and regulates neuronal and non-neuronal cell genesis

<p>Abstract</p> <p>Background</p> <p>The ability to regulate neurogenesis in the adult dentate gyrus will require further identification and characterization of the receptors regulating this process. <it>In vitro </it>and <it>in vivo </it>studies have demonstrated that neurotrophins and the p75 neurotrophin receptor (p75^NTR) can promote neurogenesis; therefore we tested the hypothesis that p75^NTRis expressed by adult dentate gyrus progenitor cells and is required for their proliferation and differentiation.</p> <p>Results</p> <p>In a first series of studies focusing on proliferation, mice received a single BrdU injection and were sacrificed 2, 10 and 48 hours later. Proliferating, BrdU-positive cells were found to express p75^NTR. In a second series of studies, BrdU was administered by six daily injections and mice were sacrificed 1 day later. Dentate gyrus sections demonstrated a large proportion of BrdU/p75^NTRco-expressing cells expressing either the NeuN neuronal or GFAP glial marker, indicating that p75^NTRexpression persists at least until early stages of maturation. In p75^NTR(-/-) mice, there was a 59% decrease in the number of BrdU-positive cells, with decreases in the number of BrdU cells co-labeled with NeuN, GFAP or neither marker of 35%, 60% and 64%, respectively.</p> <p>Conclusions</p> <p>These findings demonstrate that p75^NTRis expressed by adult dentate progenitor cells and point to p75^NTRas an important receptor promoting the proliferation and/or early maturation of not only neural, but also glial and other cell types.</p

Conversion of t11t13 CLA into c9t11 CLA in Caco-2 Cells and Inhibition by Sterculic Oil

Background : Conjugated linoleic acids (CLA), and principally c9t11 CLA, are suspected to have numerous preventive properties regarding non-infectious pathologies such as inflammatory diseases, atherosclerosis and several types of cancer. C9t11 CLA is produced in the rumen during biohydrogenation of linoleic acid, but can also be synthesized in mammalian tissues from trans-vaccenic acid (C18:1 t11) through the action of delta-9 desaturase (D9D). For several years, it is also known that c9t11 CLA can be synthesized from conjugated linolenic acids (CLnA), i.e. c9t11c13 CLnA and c9t11t13 CLnA. This study aimed at investigating to which extent and by which route c9t11 CLA can be produced from another isomer of CLA, the t11t13 CLA that is structurally very similar to c9t11t13 CLnA, in Caco-2 cells

Maternal Infection with Trypanosoma cruzi and Congenital Chagas Disease Induce a Trend to a Type 1 Polarization of Infant Immune Responses to Vaccines

Vaccines are of crucial importance to prevent morbidity and mortality due to infectious diseases in childhood. A modulation of the fetal/neonatal immune system (considered immature) toward Th1 or Th2 dominance could modify responses to vaccines administered in early life. T. cruzi is the agent of Chagas' disease, in Latin America currently infecting about 2 million women at fertile ages who are susceptible to transmitting the parasite to their fetus. In previous studies we showed that T. cruzi-infected mothers can induce a pro-inflammatory environment in their uninfected neonates (M+B−), whereas congenitally infected newborns (M+B+) are able to develop a pro-Th1 parasite-specific T cell response. In the present study, we analysed the cellular and/or antibody responses to Bacillus Calmette Guerin (BCG), hepatitis B birus (HBV), diphtheria and tetanus vaccines in 6- to 7-month-old infants living in Bolivia. M+B− infants produced more IFN-γ in response to BCG, whereas M+B+ infants developed a stronger IFN-γ response to hepatitis B, diphtheria and tetanus vaccines and enhanced antibody production to HBs antigen. These results show that both maternal infection with T. cruzi and congenital Chagas disease do not interfere with responses to BCG, hepatitis B, diphtheria and tetanus vaccines in the neonatal period and that T. cruzi infection in early life tends to favour type 1 immune responses to vaccinal antigens

Predicting Spatial Patterns of Plant Recruitment Using Animal-Displacement Kernels

For plants dispersed by frugivores, spatial patterns of recruitment are primarily influenced by the spatial arrangement and characteristics of parent plants, the digestive characteristics, feeding behaviour and movement patterns of animal dispersers, and the structure of the habitat matrix. We used an individual-based, spatially-explicit framework to characterize seed dispersal and seedling fate in an endangered, insular plant-disperser system: the endemic shrub Daphne rodriguezii and its exclusive disperser, the endemic lizard Podarcis lilfordi. Plant recruitment kernels were chiefly determined by the disperser's patterns of space utilization (i.e. the lizard's displacement kernels), the position of the various plant individuals in relation to them, and habitat structure (vegetation cover vs. bare soil). In contrast to our expectations, seed gut-passage rate and its effects on germination, and lizard speed-of-movement, habitat choice and activity rhythm were of minor importance. Predicted plant recruitment kernels were strongly anisotropic and fine-grained, preventing their description using one-dimensional, frequency-distance curves. We found a general trade-off between recruitment probability and dispersal distance; however, optimal recruitment sites were not necessarily associated to sites of maximal adult-plant density. Conservation efforts aimed at enhancing the regeneration of endangered plant-disperser systems may gain in efficacy by manipulating the spatial distribution of dispersers (e.g. through the creation of refuges and feeding sites) to create areas favourable to plant recruitment

Zfp488 promotes oligodendrocyte differentiation of neural progenitor cells in adult mice after demyelination

Basic helix-loop-helix transcription factors Olig1 and Olig2 critically regulate oligodendrocyte development. Initially identified as a downstream effector of Olig1, an oligodendrocyte-specific zinc finger transcription repressor, Zfp488, cooperates with Olig2 function. Although Zfp488 is required for oligodendrocyte precursor formation and differentiation during embryonic development, its role in oligodendrogenesis of adult neural progenitor cells is not known. In this study, we tested whether Zfp488 could promote an oligodendrogenic fate in adult subventricular zone (SVZ) neural stem/progenitor cells (NSPCs). Using a cuprizone-induced demyelination model in mice, we examined the effect of retrovirus-mediated Zfp488 overexpression in SVZ NSPCs. Our results showed that Zfp488 efficiently promoted the differentiation of the SVZ NSPCs into mature oligodendrocytes in vivo. After cuprizone-induced demyelination injury, Zfp488-transduced mice also showed significant restoration of motor function to levels comparable to control mice. Together, these findings identify a previously unreported role for Zfp488 in adult oligodendrogenesis and functional remyelination after injury