2,844 research outputs found

    Remapeamento sensorial: uma possível opção de terapia

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    Os receptores sensoriais humanos são morfologicamente especializados para realizar a transdução de estímulos específicos para o encéfalo. Entretanto, quando ocorre uma lesão, principalmente, na medula espinal, que pode ser de origem traumática e não traumática, provocam diversos graus de déficits sensoriais, disfunção autônoma, motora e esfincteriana, abaixo do nível da lesão. Com base nisso, uma nova modalidade terapêutica está sendo proposto pelo neurocientista Miguel Nicolelis, que tem como base a interface cérebro máquina, isto é, utilizar-se de outras vias para que as informações possam chegar no córtex cerebral e assim serem processadas conscientemente. conscientementeThe human sensory receptors are morphologically specialized to transduce specific stimuli into the brain. However, when an injury occurs, mainly in the spinal cord, which can be of traumatic or non-traumatic origin, it provokes various degrees of sensory deficits, autonomic, motor and sphincter dysfunction below the level of the injury. Based on this, a new therapeutic modality is being proposed by neuroscientist Miguel Nicolelis, which is based on the brain-machine interface, that is, using other pathways so that the information can reach the cerebral cortex and thus be consciously processed

    Borrelia burgdorferi OspA is an arthropod-specific transmission-blocking Lyme disease vaccine

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    Borrelia burgdorferi, the spirochetal agent of Lyme disease, is transmitted by Ixodes ticks. A vaccine based on B. burgdorferi outer surface protein (Osp) A protects mice from spirochete infection. Here we report on the expression of OspA on spirochetes inside engorging ticks and relate OspA expression to antispirochetal immunity. Spirochetes in the gut of unfed nymphal ticks were stained by an OspA antibody, whereas in feeding ticks, the majority of spirochetes in the gut and salivary glands did not stain with the antibody. Thus, OspA was not expressed on most spirochetes during transmission from the vector to the vertebrate host. To examine the mechanism of protection afforded by OspA antibody, mice were passively immunized with OspA antibody at different times relative to tick attachment. When OspA antibody was administered to mice before or at the time of tick attachment, spirochetal development events in the vector, such as growth and salivary gland invasion, were blocked and the mice were protected from B. burgdorferi infection. When OspA antibody was administered to mice 48 h after tick attachment, spirochetes persisted in the nymphs and the mice were not protected despite the presence of circulating antibodies in the host as well as in the tick blood meal. Thus, OspA immunity appears to be effective only during a narrow window time at the beginning of the blood meal when antibodies bind to OspA-expressing spirochetes in the tick gut and block transmission from the vector to the host

    Discurso do Sujeito Coletivo aplicado a medição da motivação dos alunos durante a execução de atividades

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    Neste estudo buscamos compreender como a motivação dos estudantes a aprendizagem pode ser afetada por envio de gatilhos motivacionais automáticos durante a execução das atividades em ambientes de Aprendizagem Baseada em Problemas (PBL). A metodologia para validação dos gatilhos foi desenvolvida em dois momentos: (i) em 2017 com a participação de 60 alunos do curso de Engenharia de Software; e (ii) em 2018 com 23 alunos do segundo ano do curso de Engenharia de Computação. Ao final de cada um desses estudos, os pontos de vista dos alunos foram agrupados por classe e expressos através da construção do Discurso do Sujeito Coletivo (DSC). Assim, este estudo contribui para a discussão e apresentação do DSC como abordagem capaz de auxiliar os professores durante a avaliação das atividades propostas em sala de aula, principalmente por possibilitar observar a opinião de um grupo como um único sujeito

    Avaliação Citogenética em Indivíduos Ocupacionalmente Expostos ao Chumbo

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    Realizou-se uma avaliação citogenética de indivíduos ocupacionalmente expostos ao chumbo. As anomalias que mais se apresentaram elevadas foram os Broken eggs e as binucleações celulares. A média das freqüências de células binucleadas no grupo exposto foi 3,5 vezes superior a do grupo-controle e a média das freqüências de Broken eggs no grupo exposto foi 16,5 vezes superior à  freqüência apresentada pelo grupo controle. Os dados demonstraram um alto grau de citotoxidade nos indivíduos do grupo exposto ao chumbo

    The Importance of Poisoning vs. Road Traffic Injuries as a Cause of Death in Rural Sri Lanka

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    Road traffic crashes are considered by the WHO to be the most important global cause of death from injury. However, this may not be true for large areas of rural Asia where road vehicles are uncommon. The issue is important, since emphasising the importance of road traffic crashes risks switching resources to urban areas, away from already underfunded rural regions. In this study, we compared the importance of road traffic crashes with other forms of injury in a poor rural region of South Asia.We collected data on all deaths from injury in the North Central Province of Sri Lanka (NCP; population 1,105,198 at 2001 census) over 18 months using coronial, hospital, and police data. We calculated the incidence of death from all forms of intentional and unintentional injury in the province. The annual incidence of death from injury in the province was high: 84.2 per 100,000 population. Half of the deaths were from self-harm (41.3/100,000). Poisoning (35.7/100,000)-in particular, pesticide self-poisoning (23.7/100,000)-was the most common cause of death, being 3.9-fold more common than road traffic crashes (9.1/100,000).In poor rural regions of South Asia, fatal self-harm and pesticide self-poisoning in particular are significantly more important than road traffic injuries as a cause of death. It is possible that the data used by the WHO to calculate global injury estimates are biased towards urban areas with better data collection but little pesticide poisoning. More studies are required to inform a debate about the importance of different forms of injury and how avoidable deaths from any cause can be prevented. In the meantime, marked improvements in the effectiveness of therapy for pesticide poisoning, safer storage, reduced pesticide use, or reductions in pesticide toxicity are required urgently to reduce the number of deaths from self-poisoning in rural Asia

    PfAlbas constitute a new eukaryotic DNA/RNA-binding protein family in malaria parasites

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    In Plasmodium falciparum, perinuclear subtelomeric chromatin conveys monoallelic expression of virulence genes. However, proteins that directly bind to chromosome ends are poorly described. Here we identify a novel DNA/RNA-binding protein family that bears homology to the archaeal protein Alba (Acetylation lowers binding affinity). We isolated three of the four PfAlba paralogs as part of a molecular complex that is associated with the P. falciparum-specific TARE6 (Telomere-Associated Repetitive Elements 6) subtelomeric region and showed in electromobility shift assays (EMSAs) that the PfAlbas bind to TARE6 repeats. In early blood stages, the PfAlba proteins were enriched at the nuclear periphery and partially co-localized with PfSir2, a TARE6-associated histone deacetylase linked to the process of antigenic variation. The nuclear location changed at the onset of parasite proliferation (trophozoite-schizont), where the PfAlba proteins were also detectable in the cytoplasm in a punctate pattern. Using single-stranded RNA (ssRNA) probes in EMSAs, we found that PfAlbas bind to ssRNA, albeit with different binding preferences. We demonstrate for the first time in eukaryotes that Alba-like proteins bind to both DNA and RNA and that their intracellular location is developmentally regulated. Discovery of the PfAlbas may provide a link between the previously described subtelomeric non-coding RNA and the regulation of antigenic variation

    Early Loss of Xist RNA Expression and Inactive X Chromosome Associated Chromatin Modification in Developing Primordial Germ Cells

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    The inactive X chromosome characteristic of female somatic lineages is reactivated during development of the female germ cell lineage. In mouse, analysis of protein products of X-linked genes and/or transgenes located on the X chromosome has indicated that reactivation occurs after primordial germ cells reach the genital ridges.We present evidence that the epigenetic reprogramming of the inactive X-chromosome is initiated earlier than was previously thought, around the time that primordial germ cells (PGCs) migrate through the hindgut. Specifically, we find that Xist RNA expression, the primary signal for establishment of chromosome silencing, is extinguished in migrating PGCs. This is accompanied by displacement of Polycomb-group repressor proteins Eed and Suz(12), and loss of the inactive X associated histone modification, methylation of histone H3 lysine 27.We conclude that X reactivation in primordial germ cells occurs progressively, initiated by extinction of Xist RNA around the time that germ cells migrate through the hindgut to the genital ridges. The events that we observe are reminiscent of X reactivation of the paternal X chromosome in inner cell mass cells of mouse pre-implantation embryos and suggest a unified model in which execution of the pluripotency program represses Xist RNA thereby triggering progressive reversal of epigenetic silencing of the X chromosome
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