1,511 research outputs found

    Purinergic Signaling in the Retina: From Development to Disease

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    Retinal injuries and diseases are major causes of human disability involving vision impairment by the progressive and permanent loss of retinal neurons. During development, assembly of this tissue entails a successive and overlapping, signal-regulated engagement of complex events that include proliferation of progenitors, neurogenesis, cell death, neurochemical differentiation and synaptogenesis. During retinal damage, several of these events are re-activated with both protective and detrimental consequences. Purines and pyrimidines, along with their metabolites are emerging as important molecules regulating both retinal development and the tissue\u27s responses to damage. The present review provides an overview of the purinergic signaling in the developing and injured retina. Recent findings on the presence of vesicular and channel-mediated ATP release by retinal and retinal pigment epithelial cells, adenosine synthesis and release, expression of receptors and intracellular signaling pathways activated by purinergic signaling in retinal cells are reported. The pathways by which purinergic receptors modulate retinal cell proliferation, migration and death of retinal cells during development and injury are summarized. The contribution of nucleotides to the self-repair of the injured zebrafish retina is also discussed. © 2018 Elsevier Inc

    Impact of proximal cytoplasmic droplets on quality traits and in-vitro embryo production efficiency of cryopreserved bull spermatozoa

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    Background: Proximal cytoplasmic droplets (PCDs), a remnant of germ cell cytoplasm, are common non-specific morphological defects in bovine semen. This study evaluated the effect of higher percentages of PCDs on the quality of frozen-thawed bovine semen, embryo production and early embryo development.Methods: Three ejaculates from each of five (group 1: PCD <= 1%, control) and eight adult Bos indicus bulls (group 2: PCD >= 24%) were analysed. Semen samples were examined for: post-thaw motility, vigour of movement, concentration, sperm morphology, slow thermoresistance test (STT), membrane integrity, acrosome status, mitochondrial function using fluorescent probes association (FITC-PSA, PI and JC-1) and sperm chromatin integrity using acridine orange assay. Two bulls from group 2, with 28.5% and 48.5% PCD, respectively, and three bulls from the control group, each with 0% PCD, were selected for IVF (in vitro fertilisation).Results: Semen analyses revealed a significant correlation (P < 0.01) between increased rates of PCD and sperm quality traits. Nevertheless, no differences were observed in sperm motility and vigour either before or after the STT or in the percentage of intact acrosomes (analysed by differential interference contrast microscopy (DIC) after STT), but membrane integrity, acrosome status (evaluated with FITC-PSA staining method after thawing) and mitochondrial function were reduced, when compared with group 1 (P < 0.05). The higher incidence of PCD was positively correlated to chromatin damage, especially after three hours of incubation at 37 degrees C. IVF showed similar results for bull C2 (group 1, control) and bull P2 (group 2, group with higher PCDs).Conclusion: Higher PCD levels influenced spermatozoa quality traits. IVF and embryo development data showed that cleavage, blastocyst formation and blastocyst hatching may have been influenced by the interaction of morphology traits and individual bull effects

    NOTAS E RESENHAS

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    FOTOINTERPRETAÇÃO E QUNATIFICAÇÃO PARA AVALIAÇÃO DE TRNSFORMAÇÕES NO USO DA TERRA - Miguel C. SANCHEZ CARACTERIZAÇÃO DA MODERNIZAÇÃO DA AGRICULTURA E DO DESENVOLVIMENTO RURAL EM URBELANDIA - Miguel C. SANCHEZ EMPREGO DO SENSORIAMENTO REMOTO NOS ESTUDOS DOS EFEITOS DA EROSÃO EM PAREAS DE RESERVATÓRIO - Myrna T. VIANA RECUPERAÇÃO DE RECURSOS A PARTIR DO LIXO URBANO EM RIO CLARO - Geraldo RODRIGUE

    Quinquangulin and Rubrofusarin: A Spectroscopy Study

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    In this work, excitation and emission spectra were evaluated in order to elucidate the properties of quinguangulin and rubrofusarin in water/ethanol mixture. The study demonstrates that the maximum excitation wavelength can be significantly modulated changing the proportion of organic solvent in the water/organic solvent system. Quinquangulin presented the higher wavelength of maximum excitation in an ethanol-water mixture containing 70% of water. Probably, the organization between ethanol and water molecules in this condition favors the formation of strong polar interactions with the pi* orbitals of naphthopyrones. It is interesting to register that the additional methyl group in quinquangulin seems to develop a decisive function related to the ability to formation of hydrogen bonds, altering significantly the mechanism of solute-solvent interaction. This work, which involves both theoretical and experimental analyses, demonstrates the relevance of the studies focused on solvent mixtures as well as emphasizes the potential of quinguangulin and rubrofusarin as photosensitizers.FAPESPFundacao AraucariaFAPEMIGCNPqCAPESUniv Fed Sao Joao Del Rei, Dept Zootecnia DEZOO, Campus Dom Bosco, BR-36301160 Sao Joao Del Rei, MG, BrazilUniv Vale Paraiba, Ave Shishima Hifumi 2911, BR-12244000 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Quim, Rua Prof Arthur Riedel 275, BR-09972270 Sao Paulo, BrazilUniv Fed Uberlandia, Inst Quim, Lab Fotoquim & Ciencia Mat, Uberlandia, MG, BrazilUniv Fed Goias, Dept Quim, Campus Catalao, Catalao, Go, BrazilUniv Estadual Maringa, Dept Quim, Av Colombo 5790,Zona 07, BR-87020900 Maringa, Parana, BrazilUniv Fed Rio de Janeiro, Campus Macae,Rua Aloisio da Silva Gomes 50, BR-27930560 Rio De Janeiro, BrazilUniv Estadual Campinas, Inst Quim, BR-13083970 Sao Paulo, BrazilUniv Fed Rio Grande, Escola Quim & Alimentos, Campus Carreiros Pavilhao Quim, BR-96201900 Rio Grande, RS, BrazilUniv Fed ABC, Ctr Engn Modelagem & Ciencias Sociais Aplicadas, Ave Estados 500, BR-09210580 Sao Paulo, BrazilUniv Fed ABC, Ctr Ciencias Nat & Humanas, Ave Estados 5001, BR-09210580 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Quim, Rua Prof Arthur Riedel 275, BR-09972270 Sao Paulo, BrazilFAPESP: 06/56701-3Fundacao AraucariaFAPEMIGCNPq: 474019/2012-8CNPq: 303872/2009-8CAPESWeb of Scienc

    Identification of strain-specific B-cell epitopes in Trypanosoma cruzi using genome-scale epitope prediction and high-throughput immunoscreening with peptide arrays

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    BACKGROUND: The factors influencing variation in the clinical forms of Chagas disease have not been elucidated; however, it is likely that the genetics of both the host and the parasite are involved. Several studies have attempted to correlate the T. cruzi strains involved in infection with the clinical forms of the disease by using hemoculture and/or PCR-based genotyping of parasites from infected human tissues. However, both techniques have limitations that hamper the analysis of large numbers of samples. The goal of this work was to identify conserved and polymorphic linear B-cell epitopes of T. cruzi that could be used for serodiagnosis and serotyping of Chagas disease using ELISA. METHODOLOGY: By performing B-cell epitope prediction on proteins derived from pair of alleles of the hybrid CL Brener genome, we have identified conserved and polymorphic epitopes in the two CL Brener haplotypes. The rationale underlying this strategy is that, because CL Brener is a recent hybrid between the TcII and TcIII DTUs (discrete typing units), it is likely that polymorphic epitopes in pairs of alleles could also be polymorphic in the parental genotypes. We excluded sequences that are also present in the Leishmania major, L. infantum, L. braziliensis and T. brucei genomes to minimize the chance of cross-reactivity. A peptide array containing 150 peptides was covalently linked to a cellulose membrane, and the reactivity of the peptides was tested using sera from C57BL/6 mice chronically infected with the Colombiana (TcI) and CL Brener (TcVI) clones and Y (TcII) strain. FINDINGS AND CONCLUSIONS: A total of 36 peptides were considered reactive, and the cross-reactivity among the strains is in agreement with the evolutionary origin of the different T. cruzi DTUs. Four peptides were tested against a panel of chagasic patients using ELISA. A conserved peptide showed 95.8% sensitivity, 88.5% specificity, and 92.7% accuracy for the identification of T. cruzi in patients infected with different strains of the parasite. Therefore, this peptide, in association with other T. cruzi antigens, may improve Chagas disease serodiagnosis. Together, three polymorphic epitopes were able to discriminate between the three parasite strains used in this study and are thus potential targets for Chagas disease serotyping

    Monilethrix: the use of tricoscopy in clinical diagnosis

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    Monilethrix is a Greco-Latin term that mean “hair stick”1. It is a rare genetic disorder with autosomal dominant inheritance, characterized by degeneration of the hair matrix and formation of defective cuticle. The hairs are brittle and not exceed a few inches length. The scalp is the most affected region and the most common clinical presentation is alopecia associated with keratosis follicularis2,3. The diagnosis is clinical and the tricoscopia evidence moniliformes changes (switching between wide and narrow band)Monilethrix é termo de origem greco-latina que significa “cabelo em colar”1. Trata-se de doença genética rara, com herança autossômica dominante, caracterizada por degeneração da matriz do cabelo e forma- ção de uma cutícula defeituosa. Os cabelos são quebradiços e não excedem poucos centímetros de comprimento. O couro cabeludo é a região mais afetada e a apresentação clínica mais comum é alopecia associada à queratose folicular2,3. O diagnóstico é clínico e a tricoscopia evidencia alterações moniliformes (alternância entre bandas largas e estreitas

    Study of star-forming galaxies in SDSS up to redshift 0.4 II. Evolution from the fundamental parameters: mass, metallicity & SFR

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    To understand the formation and evolution of galaxies, it is important to have a full comprehension of the role played by the metallicity, star formation rate (SFR), morphology, and color. The interplay of these parameters at different redshifts will substantially affect the evolution of galaxies and, as a consequence, the evolution of them will provide important clues and constraints on the galaxy evolution models. In this work we focus on the evolution of the SFR, metallicity of the gas, and morphology of galaxies at low redshift in search of signs of evolution. We use the S2N2 diagnostic diagram as a tool to classify star--forming, composite, and AGN galaxies. We analyzed the evolution of the three principal BPT diagrams, estimating the SFR and specific SFR (SSFR) for our samples of galaxies, studying the luminosity and mass-metallicity relations, and analyzing the morphology of our sample of galaxies through the g-r color, concentration index, and SSFR. We found that the S2N2 is a reliable diagram to classify star--forming, composite, and AGNs galaxies. We demonstrate that the three principal BPT diagrams show an evolution toward higher values of [OIII]5007/Hb due to a metallicity decrement. We found an evolution in the mass-metallicity relation of ~ 0.2 dex for the redshift range 0.3 < z < 0.4 compared to our local one. From the analysis of the evolution of the SFR and SSFR as a function of the stellar mass and metallicity, we discovered a group of galaxies with higher SFR and SSFR at all redshift samples, whose morphology is consistent with those of late-type galaxies. Finally, the comparison of our local (0.04<z<0.1) with our higher redshift sample (0.3<z<0.4), show that the metallicity, the SFR and morphology, evolve toward lower values of metallicity, higher SFRs, and late--type morphologies for the redshift range 0.3<z<0.4Comment: 16 pages, 15 figures. Accepted for publication in A&

    The C Allele of rs5743836 Polymorphism in the Human TLR9 Promoter Links IL-6 and TLR9 Up-Regulation and Confers Increased B-Cell Proliferation

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    In humans, allelic variants in Toll-like receptors (TLRs) associate with several pathologies. However, the underlying cellular and molecular mechanisms of this association remain largely unknown. Analysis of the human TLR9 promoter revealed that the C allele of the rs5743836 polymorphism generates several regulatory sites, including an IL-6-responding element. Here, we show that, in mononuclear cells carrying the TC genotype of rs5743836, IL-6 up-regulates TLR9 expression, leading to exacerbated cellular responses to CpG, including IL-6 production and B-cell proliferation. Our study uncovers a role for the rs5743836 polymorphism in B-cell biology with implications on TLR9-mediated diseases and on the therapeutic usage of TLR9 agonists/antagonists

    Polymorphisms in folate-metabolizing genes, chromosome damage, and risk of Down syndrome in Italian women: identification of key factors using artificial neural networks

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    <p>Abstract</p> <p>Background</p> <p>Studies in mothers of Down syndrome individuals (MDS) point to a role for polymorphisms in folate metabolic genes in increasing chromosome damage and maternal risk for a Down syndrome (DS) pregnancy, suggesting complex gene-gene interactions. This study aimed to analyze a dataset of genetic and cytogenetic data in an Italian group of MDS and mothers of healthy children (control mothers) to assess the predictive capacity of artificial neural networks assembled in TWIST system in distinguish consistently these two different conditions and to identify the variables expressing the maximal amount of relevant information to the condition of being mother of a DS child.</p> <p>The dataset consisted of the following variables: the frequency of chromosome damage in peripheral lymphocytes (BNMN frequency) and the genotype for 7 common polymorphisms in folate metabolic genes (<it>MTHFR </it>677C>T and 1298A>C, <it>MTRR </it>66A>G, <it>MTR </it>2756A>G, <it>RFC1 </it>80G>A and <it>TYMS </it>28bp repeats and 1494 6bp deletion). Data were analysed using TWIST system in combination with supervised artificial neural networks, and a semantic connectivity map.</p> <p>Results</p> <p>TWIST system selected 6 variables (BNMN frequency, <it>MTHFR </it>677TT, <it>RFC1 </it>80AA, <it>TYMS </it>1494 6bp +/+, <it>TYMS </it>28bp 3R/3R and <it>MTR </it>2756AA genotypes) that were subsequently used to discriminate between MDS and control mothers with 90% accuracy. The semantic connectivity map provided important information on the complex biological connections between the studied variables and the two conditions (being MDS or control mother).</p> <p>Conclusions</p> <p>Overall, the study suggests a link between polymorphisms in folate metabolic genes and DS risk in Italian women.</p

    MOONRISE: The Main MOONS GTO Extragalactic Survey

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    The MOONS instrument possesses an exceptional combination of large multiplexing, high sensitivity, broad simultaneous spectral coverage (from optical to near-infrared bands), large patrol area and high fibre density. These properties provide the unprecedented potential of enabling, for the very first time, SDSS-like surveys around Cosmic Noon (z~1-2.5), when the star formation rate in the Universe peaked. The high-quality spectra delivered by MOONS will sample the same nebular and stellar diagnostics observed in extensive surveys of local galaxies, providing an accurate and consistent description of the evolution of various physical properties of galaxies, and hence a solid test of different scenarios of galaxy formation and transformation. Most importantly, by spectroscopically identifying hundreds of thousands of galaxies at high redshift, the MOONS surveys will be capable of determining the environments in which primeval galaxies lived and will reveal how such environments affected galaxy evolution. In this article, we specifically focus on the main Guaranteed Time Observation (GTO) MOONS extragalactic survey, MOONRISE, by providing an overview of its scientific goals and observing strategy
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