875 research outputs found

    Telomere Length and Its Relation to Human Health

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    Telomeres are complex nucleotide sequences that cap the end of chromosomes from degradation, unwanted recombination‐fusion, inappropriate activation of DNA damage response and play a critical role in cell division and chromosome stability. There is growing evidence that telomere stability can be affected by occupational and environmental exposure, as some of these factors have been correlated with increase in inflammation, oxidative stress, DNA damage, chromosome aberration, and epigenetic alterations. Both extremely short and long telomeres have been associated with neurodegenerative, cardiovascular diseases (CVD) and cancer risk. Occupational and environmental exposure to several synthetic and natural chemicals has been found to be associated with changes in telomere length, although the molecular mechanism is not fully understood. Telomeric DNA is relatively less capable of repair, resulting in accelerated shortening during the cell cycle and replicative senescence. It is recognized that diet plays an important role in telomere maintenance. Prevention of exposure to environmental and occupational hazards as well as psychological stressors can reduce the risk of telomere instability. This review provides a broad evaluation of the associated mechanism between human health and environmental and occupational exposure with telomere length, including recent findings and future perspectives

    Hypoxia Augments Outgrowth Endothelial Cell (OEC) Sprouting and Directed Migration in Response to Sphingosine-1-Phosphate (S1P)

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    Therapeutic angiogenesis provides a promising approach to treat ischemic cardiovascular diseases through the delivery of proangiogenic cells and/or molecules. Outgrowth endothelial cells (OECs) are vascular progenitor cells that are especially suited for therapeutic strategies given their ease of noninvasive isolation from umbilical cord or adult peripheral blood and their potent ability to enhance tissue neovascularization. These cells are recruited to sites of vascular injury or tissue ischemia and directly incorporate within native vascular endothelium to participate in neovessel formation. A better understanding of how OEC activity may be boosted under hypoxia with external stimulation by proangiogenic molecules remains a challenge to improving their therapeutic potential. While vascular endothelial growth factor (VEGF) is widely established as a critical factor for initiating angiogenesis, sphingosine-1-phosphate (S1P), a bioactive lysophospholipid, has recently gained great enthusiasm as a potential mediator in neovascularization strategies. This study tests the hypothesis that hypoxia and the presence of VEGF impact the angiogenic response of OECs to S1P stimulation in vitro. We found that hypoxia altered the dynamically regulated S1P receptor 1 (S1PR1) expression on OECs in the presence of S1P (1.0 mu M) and/or VEGF (1.3 nM). the combined stimuli of S1P and VEGF together promoted OEC angiogenic activity as assessed by proliferation, wound healing, 3D sprouting, and directed migration under both normoxia and hypoxia. Hypoxia substantially augmented the response to S1P alone, resulting in similar to 6.5-fold and similar to 25-fold increases in sprouting and directed migration, respectively. Overall, this report highlights the importance of establishing hypoxic conditions in vitro when studying ischemia-related angiogenic strategies employing vascular progenitor cells.University of California, DavisAmerican Heart Association (AHA)Univ Calif Davis, Dept Biomed Engn, Davis, CA 95616 USAUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilUniv Calif Davis, Dept Neurobiol Physiol & Behav, Davis, CA 95616 USAUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilAmerican Heart Association (AHA): 15PRE22930044Web of Scienc

    Semantic Relation Classification: Task Formalisation and Refinement

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    The identification of semantic relations between terms within texts is a fundamental task in Natural Language Processing which can support applications requiring a lightweight semantic interpretation model. Currently, semantic relation classification concentrates on relations which are evaluated over open-domain data. This work provides a critique on the set of abstract relations used for semantic relation classification with regard to their ability to express relationships between terms which are found in a domain-specific corpora. Based on this analysis, this work proposes an alternative semantic relation model based on reusing and extending the set of abstract relations present in the DOLCE ontology. The resulting set of relations is well grounded, allows to capture a wide range of relations and could thus be used as a foundation for automatic classification of semantic relations

    Knowledge and attitude of parents or caretakers regarding transmissibility os caries disease

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    Dental caries is a transmissible infectious disease in which mutans streptococci are generally considered to be the main etiological agents. Although the transmissibility of dental caries is relatively well established in the literature, little is known whether information regarding this issue is correctly provided to the population. The present study aimed at evaluating, by means of a questionnaire, the knowledge and usual attitude of 640 parents and caretakers regarding the transmissibility of caries disease. Most interviewed adults did not know the concept of dental caries being an infectious and transmissible disease, and reported the habit of blowing and tasting food, sharing utensils and kissing the children on their mouth. 372 (58.1%) adults reported that their children had already been seen by a dentist, 264 (41.3%) answered that their children had never gone to a dentist, and 4 (0.6%) did not know. When the adults were asked whether their children had already had dental caries, 107 (16.7%) answered yes, 489 (76.4%) answered no, and 44 (6.9%) did not know. Taken together, these data reinforce the need to provide the population with some important information regarding the transmission of dental caries in order to facilitate a more comprehensive approach towards the prevention of the disease

    ALTERAÇÕES MORFOLÓGICAS DE LEUCÓCITOS E TROMBÓCITOS SANGUÍNEOS EM Piaractus mesopotamicus DURANTE A SEPSE

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    Sepsis is defined as organ dysfunction with high mortality. During this process, the hematological system plays a critical role. Thus, the work aimed to analyze the morphological changes in the leukogram and thrombogram by the indirect method in the course of sepsis in Piaractus mesopotamicus. For this, 98 pacus were used, divided into two groups, one received 0.5 ml of sterile 0.65% sodium chloride solution (control) and the other received the same volume containing the bacterial inoculum (1.8 x 108 CFU/ml – challenge). To assess such changes in the evolution of sepsis, blood samples were collected from fish 1, 3, 6 and 9 hours after inoculation and in the control group (n = 10). One aliquot of the blood was used for blood culture and another for determining the number of leukocytes and thrombotics by the indirect method and the evaluation of morphological changes in blood extensions. Aeromonosis was confirmed by positive blood culture in all samples from the challenged groups. The leukogram analysis showed a significant increase (p <0.05) of leukocytes in the later times, 9 and 6 HPI in relation to the control group. Differential analysis showed leukopenia (p <0.05; 3 HPI) and consumption of thrombocytes. It was found that with the increase of the infection the septicemic pacus develops a picture of granulocytosis and monocytosis (p <0.05). It was concluded that inoculation with A. hydrophila induced sepsis with positive blood culture with leukocytosis in the challenged pacus and caused an intense change in the leukocyte and thrombotic morphology.KEYWORDS: Hemoculture, Leukogram, Morphology, Aeromonas hydrophila, Teleosts.La sepsis se define como disfunción orgánica con alta mortalidad. Durante este proceso, el sistema hematológico juega un papel crítico. Por lo tanto, el trabajo tuvo como objetivo analizar los cambios morfológicos en el leucograma y el trombograma por el método indirecto en el curso de la sepsis en Piaractus mesopotamicus. Para esto, se utilizaron 98 pacus, divididos en dos grupos, uno recibió 0,5 ml de solución estéril de cloruro de sodio al 0,65% (control) y el otro recibió el mismo volumen que contenía el inóculo bacteriano (1,8 x 108 UFC / ml - desafío). Para evaluar dichos cambios en la evolución de la sepsis, se recogieron muestras de sangre de peces 1, 3, 6 y 9 horas después de la inoculación y en el grupo de control (n = 10). Una parte alícuota de la sangre se usó para el hemocultivo y otra para determinar el número de leucocitos y trombóticos mediante el método indirecto y la evaluación de los cambios morfológicos en las extensiones de sangre. La aeromonosis se confirmó por hemocultivo positivo en todas las muestras de los grupos desafiados. El análisis de leucogramas mostró un aumento significativo (p <0.05) de leucocitos en los últimos tiempos, 9 y 6 HPI en relación con el grupo de control. El análisis diferencial mostró leucopenia (p <0.05; 3 HPI) y consumo de trombocitos. Se encontró que con el aumento de la infección, el pacus septicémico desarrolla una imagen de granulocitosis y monocitosis (p <0.05). Se concluyó que la inoculación con A. hydrophila indujo sepsis con hemocultivo positivo con leucocitosis en pacus desafiado y causa un cambio intenso en los leucocitos y la morfología trombóticaPALABRAS CLAVES Hemocultivo, Leucograma, Morfología, Aeromonas hydrophila, Teleósteos.A sepse é definida como disfunção orgânica com alta mortalidade. Durante esse processo o sistema hematológico desempenha um papel crítico. Assim, o trabalho objetivou analisar as alterações morfológicas no leucograma e no trombograma pelo método indireto no curso da sepse em Piaractus mesopotamicus. Para tanto, foram utilizados 98 pacus, divididos em dois grupos, um deles recebeu 0,5 ml de solução de cloreto de sódio esterilizada a 0,65% (controle) e outro recebeu o mesmo volume contendo o inoculo bacteriano (18 x 108 CFU/ml – desafio). Para avaliar tais alterações na evolução da sepse foram realizadas coletas de sangue dos peixes 1, 3, 6 e 9 horas após inoculação e no grupo controle (n=10). Uma alíquota do sangue foi destina a hemocultura e outra na determinação do número de leucócitos e de trombóticos pelo método indireto e a avaliação das alterações morfológicas nas extensões sanguíneas. A aeromonose foi confirmada pela hemocultura positiva em todas as amostras dos grupos desafiados. A análise do leucograma demonstrou aumento significativa (p<0,05) dos leucócitos nos tempos mais tardios, 9 e 6 HPI em relação ao grupo controle. Da análise diferencial observou-se leucopenia (p<0,05; 3 HPI) e consumo dos trombócitos. Verificou-se que com o aumento da infecção os pacus septicêmicos desenvolvem um quadro de granulocitose e monocitose (p<0,05). Concluiu-se que a inoculação com A. hydrophila induziu a sepse com hemocultura positiva com leucocitose nos pacus desafiados e causa intensa alteração na morfologia dos leucócitos e trombóticos.PALAVRAS-CHAVE: Hemocultura, Leucograma, Morfologia, Aeromonas hydrophila, Teleósteos
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