262 research outputs found

    Retinal Structural Changes in Preterm Children without Retinopathy of Prematurity

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    Purpose: The aim of this study was to compare all retinal layers' thickness in full-term and preterm children without retinopathy of prematurity (ROP). Methods: Cross-sectional study including two groups of patients: group 1 children with history of preterm gestation without ROP (gestational age < 37 weeks) and group 2 healthy children with history of full-term gestation. All subjects underwent an ophthalmic examination including spectral domain-optical coherence tomography. After automatic retinal segmentation, each retinal layer thickness (eight separate layers and overall thickness) was calculated in all nine Early Treatment Diabetic Retinopathy Study areas. Demographic, systemic, gestational, and birth data were collected. Generalized additive regression models were used to analyze the data. Results: Fifty-one children (51 eyes) were recruited, 19 full-term and 32 preterm children, mean age at ophthalmic examination of 10.58 (4.21) and 14.13 (3.16), respectively. In multivariable analysis, the preterm group's retinal thickness was significantly decreased in total retina nasal outer sector, ganglion cell layer (GCL), and inner plexiform layer (IPL), specifically GCL temporal outer (p = 0.010), GCL superior outer (p = 0.009), IPL temporal outer (p = 0.022), and IPL superior outer (p = 0.004), when compared with full-term group. From the variables compared only with birth head circumference that influenced the models, a non-linear association was identified and consequently modeled with splines through a generalized additive model. Conclusion: This study suggests that preterm children without ROP have structural retinal alterations, mostly in GCL and IPL in outer areas of the macula. Therefore, it is crucial to question gestational history since these retinal changes may be found later in life leading to useless investigation.info:eu-repo/semantics/publishedVersio

    Distribution of genetic diversity reveals colonization patterns and philopatry of the loggerhead sea turtles across geographic scales.

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    Understanding the processes that underlie the current distribution of genetic diversity in endangered species is a goal of modern conservation biology. Specifically, the role of colonization and dispersal events throughout a species' evolutionary history often remains elusive. The loggerhead sea turtle (Caretta caretta) faces multiple conservation challenges due to its migratory nature and philopatric behaviour. Here, using 4207 mtDNA sequences, we analysed the colonisation patterns and distribution of genetic diversity within a major ocean basin (the Atlantic), a regional rookery (Cabo Verde Archipelago) and a local island (Island of Boa Vista, Cabo Verde). Data analysis using hypothesis-driven population genetic models suggests the colonization of the Atlantic has occurred in two distinct waves, each corresponding to a major mtDNA lineage. We propose the oldest lineage entered the basin via the isthmus of Panama and sequentially established aggregations in Brazil, Cabo Verde and in the area of USA and Mexico. The second lineage entered the Atlantic via the Cape of Good Hope, establishing colonies in the Mediterranean Sea, and from then on, re-colonized the already existing rookeries of the Atlantic. At the Cabo Verde level, we reveal an asymmetric gene flow maintaining links across island-specific nesting groups, despite significant genetic structure. This structure stems from female philopatric behaviours, which could further be detected by weak but significant differentiation amongst beaches separated by only a few kilometres on the island of Boa Vista. Exploring biogeographic processes at diverse geographic scales improves our understanding of the complex evolutionary history of highly migratory philopatric species. Unveiling the past facilitates the design of conservation programmes targeting the right management scale to maintain a species' evolutionary potential

    The innate immune sensor Toll-like receptor 2 controls the senescence-associated secretory phenotype

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    Cellular senescence is a stress response program characterized by a robust cell cycle arrest and the induction of a proinflammatory senescence-associated secretory phenotype (SASP) that is triggered through an unknown mechanism. Here, we show that, during oncogene-induced senescence (OIS), the Toll-like receptor 2 (TLR2) and its partner TLR10 are key mediators of senescence in vitro and in murine models. TLR2 promotes cell cycle arrest by regulating the tumor suppressors p53-p21 , p16 , and p15 and regulates the SASP through the induction of the acute-phase serum amyloids A1 and A2 (A-SAAs) that, in turn, function as the damage-associated molecular patterns (DAMPs) signaling through TLR2 in OIS. Last, we found evidence that the cGAS-STING cytosolic DNA sensing pathway primes TLR2 and A-SAAs expression in OIS. In summary, we report that innate immune sensing of senescence-associated DAMPs by TLR2 controls the SASP and reinforces the cell cycle arrest program in OIS

    Long-term survey of sea turtles (Caretta caretta) reveals correlations between parasite infection, feeding ecology, reproductive success and population dynamics.

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    Long-term monitoring of host-parasite interactions is important for understanding the consequences of infection on host fitness and population dynamics. In an eight-year survey of the loggerhead sea turtle (Caretta caretta) population nesting in Cabo Verde, we determined the spatiotemporal variation of Ozobranchus margoi, a sanguivorous leech best known as a vector for sea turtle fibropapilloma virus. We quantified O. margoi association with turtles' δ15N and δ13C stable isotopes to identify where infection occurs. We then measured the influence of infection on reproduction and offspring fitness. We found that parasite prevalence has increased from 10% of the population in 2010, to 33% in 2017. Stable isotope analysis of host skin samples suggests transmission occurs within the host's feeding grounds. Interestingly, we found a significant interaction between individual size and infection on the reproductive success of turtles. Specifically, small, infected females produced fewer offspring of poorer condition, while in contrast, large, infected turtles produced greater clutch sizes and larger offspring. We interpret this interaction as evidence, upon infection, for a size-dependent shift in reproductive strategy from bet hedging to terminal investment, altering population dynamics. This link between infection and reproduction underscores the importance of using long-term monitoring to quantify the impact of disease dynamics over time

    A Stochastic Step Model of Replicative Senescence Explains ROS Production Rate in Ageing Cell Populations

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    Increases in cellular Reactive Oxygen Species (ROS) concentration with age have been observed repeatedly in mammalian tissues. Concomitant increases in the proportion of replicatively senescent cells in ageing mammalian tissues have also been observed. Populations of mitotic human fibroblasts cultured in vitro, undergoing transition from proliferation competence to replicative senescence are useful models of ageing human tissues. Similar exponential increases in ROS with age have been observed in this model system. Tracking individual cells in dividing populations is difficult, and so the vast majority of observations have been cross-sectional, at the population level, rather than longitudinal observations of individual cells

    Participation, knowledge production, and evaluative research: participation by different actors in a mental health study

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    This article reflects on the interrelations between participation, knowledge production, and public policy evaluation in light of issues from our own experience with evaluative research on a municipal network of Psychosocial Care Centers (CAPS) in Brazil. The article discusses the coordination of the complex process and the potentials and limits of partnerships for conducting qualitative evaluative studies in mental health with participation by different social actors. The authors conclude that qualitative evaluative research aligned with the perspective of including different points of view representing various segments is the best approach for understanding the numerous spin-offs from the implementation of services linked to the Brazilian psychiatric reform movement, given the inherent specificities of the mental health field.No presente texto apresentamos considerações sobre pesquisa avaliativa qualitativa e participativa com base em investigação desta natureza realizada junto a uma rede municipal de Centros de Atenção Psicossocial (CAPS) ligados ao Sistema Único de Saúde (SUS). A coordenação do complexo processo, bem como as potencialidades e limites do estabelecimento de parcerias para a realização de trabalhos de investigação avaliativa qualitativa em saúde mental, com a inclusão de diferentes atores sociais, são aqui discutidas. Concluímos que a pesquisa avaliativa qualitativa aliada à perspectiva de inclusão de distintos pontos de vista dos vários segmentos envolvidos é a que melhor se adequa à compreensão dos muitos desdobramentos oriundos da implementação de serviços ligados ao movimento de reforma psiquiátrica brasileira, dado as especificidades inerentes ao campo da saúde mental.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP)Universidade Estadual de Campinas FCMUNIFESPSciEL

    Role of cellular senescence and NOX4-mediated oxidative stress in systemic sclerosis pathogenesis.

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    Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by progressive fibrosis of skin and numerous internal organs and a severe fibroproliferative vasculopathy resulting frequently in severe disability and high mortality. Although the etiology of SSc is unknown and the detailed mechanisms responsible for the fibrotic process have not been fully elucidated, one important observation from a large US population study was the demonstration of a late onset of SSc with a peak incidence between 45 and 54 years of age in African-American females and between 65 and 74 years of age in white females. Although it is not appropriate to consider SSc as a disease of aging, the possibility that senescence changes in the cellular elements involved in its pathogenesis may play a role has not been thoroughly examined. The process of cellular senescence is extremely complex, and the mechanisms, molecular events, and signaling pathways involved have not been fully elucidated; however, there is strong evidence to support the concept that oxidative stress caused by the excessive generation of reactive oxygen species may be one important mechanism involved. On the other hand, numerous studies have implicated oxidative stress in SSc pathogenesis, thus, suggesting a plausible mechanism in which excessive oxidative stress induces cellular senescence and that the molecular events associated with this complex process play an important role in the fibrotic and fibroproliferative vasculopathy characteristic of SSc. Here, recent studies examining the role of cellular senescence and of oxidative stress in SSc pathogenesis will be reviewed

    Source Evaluation and Trace Metal Contamination in Benthic Sediments from Equatorial Ecosystems Using Multivariate Statistical Techniques

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    race metals (Cd, Cr, Cu, Ni and Pb) concentrations in benthic sediments were analyzed through multi-step fractionation scheme to assess the levels and sources of contamination in estuarine, riverine and freshwater ecosystems in Niger Delta (Nigeria). The degree of contamination was assessed using the individual contamination factors (ICF) and global contamination factor (GCF). Multivariate statistical approaches including principal component analysis (PCA), cluster analysis and correlation test were employed to evaluate the interrelationships and associated sources of contamination. The spatial distribution of metal concentrations followed the pattern Pb>Cu>Cr>Cd>Ni. Ecological risk index by ICF showed significant potential mobility and bioavailability for Cu, Cu and Ni. The ICF contamination trend in the benthic sediments at all studied sites was Cu>Cr>Ni>Cd>Pb. The principal component and agglomerative clustering analyses indicate that trace metals contamination in the ecosystems was influenced by multiple pollution sources
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