993 resultados para Panzani, Gregorio, -1662
Resumo:
The blood brain barrier (BBB) and the blood cerebrospinal fluid barrier (BCSFB) form the barriers of the brain. These barriers are essential not only for the protection of the brain, but also in regulating the exchange of cells and molecules in and out of the brain. The choroid plexus (CP) epithelial cells and the arachnoid membrane form the BCSFB. The CP is structurally divided into two independent compartments: one formed by a unique and continuous line of epithelial cells that rest upon a basal lamina; and, a second consisting of a central core formed by connective and highly vascularized tissue populated by diverse cell types (fibroblasts, macrophages and dendritic cells). Here, we review how the CP transcriptome and secretome vary depending on the nature and duration of the stimuli to which the CP is exposed. Specifically, when the peripheral stimulation is acute the CP response is rapid, strong and transient, whereas if the stimulation is sustained in time the CP response persists but it is weaker. Furthermore, not all of the epithelium responds at the same time to peripheral stimulation, suggesting the existence of a synchrony system between individual CP epithelial cells.
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Sandwich geometries, mainly in the form of panels and beams, are commonly applied in various transportation industries, such as aerospace, aeronautic and automotive. Sandwich geometries represent important advantages in structural applications, namely high specific stiffness, low weight, and possibility of design optimization prior to manufacturing. The aim of this paper is to uncover the influence of the number of reinforcements (ribs), and of the thickness on the mechanical behavior of all-metal sandwich panels subjected to uncoupled bending and torsion loadings. In this study, four geometries are compared. The orientation of the reinforcements and the effect of transversal ribs are also considered in this study. It is shown that the all the relations are non-linear, despite the elastic nature of the analysis in the Finite Element software ANSYS MECHANICAL APDL.
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Neural stem cells (NSCs) and mesenchymal stem cells (MSCs) share few characteristics apart from self-renewal and multipotency. In fact, the neurogenic and osteogenic stem cell niches derive from two distinct embryonary structures; while the later originates from the mesoderm, as all the connective tissues do, the first derives from the ectoderm. Therefore, it is highly unlikely that stem cells isolated from one niche could form terminally differentiated cells from the other. Additionally, these two niches are associated to tissues/systems (e.g., bone and central nervous system) that have markedly different needs and display diverse functions within the human body. Nevertheless they do share common features. For instance, the differentiation of both NSCs and MSCs is intimately associated with the bone morphogenetic protein family. Moreover, both NSCs and MSCs secrete a panel of common growth factors, such as nerve growth factor (NGF), glial derived neurotrophic factor (GDNF), and brain derived neurotrophic factor (BDNF), among others. But it is not the features they share but the interaction between them that seem most important, and worth exploring; namely, it has already been shown that there are mutually beneficially effects when these cell types are co-cultured in vitro. In fact the use of MSCs, and their secretome, become a strong candidate to be used as a therapeutic tool for CNS applications, namely by triggering the endogenous proliferation and differentiation of neural progenitors, among other mechanisms. Quite interestingly it was recently revealed that MSCs could be found in the human brain, in the vicinity of capillaries. In the present review we highlight how MSCs and NSCs in the neurogenic niches interact. Furthermore, we propose directions on this field and explore the future therapeutic possibilities that may arise from the combination/interaction of MSCs and NSCs.
Resumo:
OBJETIVO: Verificar a associação entre perfil lipídico e medidas de obesidade corporal global e central em mulheres com idade superior a 60 anos. MÉTODOS: A amostra foi composta por 388 mulheres, com mais de 60 anos de idade (média, 69,0; desvio padrão, 5,9 anos). O perfil lipídico foi determinado por meio das dosagens de colesterol total (CT), colesterol de lipoproteína de alta densidade (HDL-colesterol), colesterol de lipoproteína de baixa densidade (LDL-colesterol) e triglicerídeos (TG). A obesidade global foi mensurada pelo índice de massa corporal (IMC) e pelas dobras cutâneas (DC), e a obesidade central foi mensurada pela circunferência da cintura (CC) e pela relação cintura-quadril (RCQ). A análise estatística foi realizada por meio da correlação parcial ajustada para a idade e ANOVA one-way (p < 0,05). RESULTADOS: Os valores médios encontrados nas variáveis de adiposidade corporal e nos componentes do perfil lipídico indicam elevado risco aterogênico. Além disso, os indicadores de obesidade tanto global como central foram diretamente associados com os níveis de TG e inversamente associados com os níveis de HDL-colesterol. CONCLUSÃO: A análise de correlação parcial e a maior variância encontrada na CC e na RCQ com os componentes do lipidograma sugerem que ambos os métodos podem auxiliar no diagnóstico precoce da aterosclerose.
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OBJETIVO: Examinar como a adiposidade global e a adiposidade abdominal, expressas pela circunferência da cintura (CC), pelo índice de massa corporal (IMC) e pelo somatório de dobras cutâneas (sigmaDC), influenciam os níveis de proteína C-reativa (PCR) em mulheres idosas. MÉTODOS: A amostra foi composta por 387 mulheres idosas, com idade superior a 60 anos (média, 68,9; desvio padrão, 5,9 anos). Foram avaliados o IMC, a CC, o sigmaDC, e os níveis de PCR. Foi utilizada a análise estatística ANOVA one-way para verificar as diferenças nas variáveis entre as categorias investigadas. Para avaliar a influência das medidas de adiposidade nos níveis de PCR foi utilizada a regressão logística. O nível de significância adotado foi de p < 0,05. RESULTADOS: A análise de variância demonstrou que o valor médio da CC foi menor na categoria normal de PCR, quando comparada aos níveis elevados de PCR. A regressão logística analisou a influência dos quartis do IMC, da CC e do sigmaDC nos níveis de PCR, em que apenas a CC foi preditora de níveis elevados de PCR, tendo o quartil extremo superior (ponto de corte de 94,0 cm) apresentado níveis quase duas vezes maiores que o quartil extremo inferior (risco estimado = 2,23; intervalo de confiança de 95% = 1,92-4,18; p = 0,012). CONCLUSÃO: Os resultados do presente estudo apontam que a adiposidade abdominal é um forte preditor de níveis elevados de PCR.
Resumo:
A mosca-das-frutas-sul-americana, Anastrepha fraterculus (Wiedemann, 1830), é uma das principais pragas da fruticultura no Brasil. Durante a alimentação, as larvas fazem galerias nos frutos, alterando o sabor e prejudicando a produção e comercialização dos mesmos. O presente trabalho teve como objetivo estudar fatores envolvidos na escolha do hospedeiro por A. fraterculus. Foram avaliadas as respostas eletroantenográficas de machos e fêmeas a extratos etanólicos de frutos verdes e maduros de pessegueiro - Prunus persica, cultivar Chimarrita (Rosaceae), pitangueira - Eugenia uniflora (Myrtaceae), guabirobeira - Campomanesia xanthocarpa (Myrtaceae) e araçazeiro - Psidium cattleianum (Myrtaceae). Foram também observadas as influências da cor (amarela, verde e vermelha) e da composição do substrato de oviposição (polpas de araçá, guabiroba, pitanga e pêssego) na fecundidade da espécie. As respostas eletroantenográficas de fêmeas foram significativamente distintas para os extratos de guabiroba verde e madura, araçá maduro e pitanga verde. Em antenas de machos, as maiores despolarizações médias foram registradas em resposta aos extratos de guabiroba verde e madura, araçá verde e maduro e pitanga verde. As respostas eletrofisiológicas geradas não diferiram estatisticamente entre os sexos, para todos os tratamentos. A cor do substrato não afetou a oviposição. As fêmeas ovipositaram mais nos substratos contendo polpa de pêssego e de guabiroba, quando comparados aos respectivos controles.
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A description of the species Lymnaea diaphana King, 1830 is presented, on the basis of material collected at its type-locality, San Gregorio, on the north coast of the Strait of Magellan, in the Chilean province of Magallanes. It may be identified by the following characters taken together: adult shell over 10 mm in length, whorls inflated, regularly convex, separated by a well-marked suture, aperture ovate occupying about half the shell length; renal organ forming an approximately right angle with the ureter; pouch of the oviduct well noticeable high on the right ventral surface and on the right side of the nidamental gland; uterus bent to the right into an approximately right angle; body of the spermatheca projected into the pulmonary cavity and adhered to the pericardium and to the roof of the pulmonary cavity; spermiduct highly sinuous, folding dorsalward between the left half of the oviduct and the left shoulder of the nidamental gland, and then winding on ventralward to reach the prostate on the middle line; prostate voluminous, convex on the left, pushed in on the right, with a deep dorsal furrow corresponding to a fold which projects into the prostatic lumen and is more developed at the fore half of the organ; apical end of the penial sheath with about six minute protuberances corresponding to inner chambers; prepuce from about as long about twice as long as the penial sheath, with some variation beyond those limits; lateral teeth of the radula basically tricuspid, with a usually simple ectocone which may show a bifid or trifid point. A diagnosis between lymnaea diaphana and three other lymnaeids which also occur in South America and were previously studied by the author - L. columella, L. viatrix and L. rupestris - is presented.
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Drugs are a rare cause of pancreatitis. Whereas some drugs are well known to induce an attack of pancreatitis, some people may be more prone to develop pancreatitis because of personal susceptibility. We describe a recurrent case of acute pancreatitis after administration of several drugs in a patient with intestinal inflammatory bowel disease that needed to be treated with subsequent antiinflammatory agents. Genetic mutation in the CFTR gene was found in the patient that led us to postulate that CFTR was a trigger for drug-induced acute pancreatitis. In conclusion, genetic analysis should be advised in case of recurrent pancreatitis in patient with intestinal inflammatory bowel disease.
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Oxytocin (OT) is thought to play an important role in human interpersonal information processing and behavior. By inference, OT should facilitate empathic responding, i.e. the ability to feel for others and to take their perspective. In two independent double-blind, placebo-controlled between-subjects studies, we assessed the effect of intranasally administered OT on affective empathy and perspective taking, whilst also examining potential sex differences (e.g., women being more empathic than men). In study 1, we provided 96 participants (48 men) with an empathy scenario and recorded self reports of empathic reactions to the scenario, while in study 2, a sample of 120 individuals (60 men) performed a computerized implicit perspective taking task. Whilst results from Study 1 showed no influence of OT on affective empathy, we found in Study 2 that OT exerted an effect on perspective taking ability in men. More specifically, men responded faster than women in the placebo group but they responded as slowly as women in the OT group. We conjecture that men in the OT group adopted a social perspective taking strategy, such as did women in both groups, but not men in the placebo group. On the basis of results across both studies, we suggest that self-report measures (such as used in Study 1) might be less sensitive to OT effects than more implicit measures of empathy such as that used in Study 2. If these assumptions are confirmed, one could infer that OT effects on empathic responses are more pronounced in men than women, and that any such effect is best studied using more implicit measures of empathy rather than explicit self-report measures.
Resumo:
Abnormalities in the topology of brain networks may be an important feature and etiological factor for psychogenic non-epileptic seizures (PNES). To explore this possibility, we applied a graph theoretical approach to functional networks based on resting state EEGs from 13 PNES patients and 13 age- and gender-matched controls. The networks were extracted from Laplacian-transformed time-series by a cross-correlation method. PNES patients showed close to normal local and global connectivity and small-world structure, estimated with clustering coefficient, modularity, global efficiency, and small-worldness (SW) metrics, respectively. Yet the number of PNES attacks per month correlated with a weakness of local connectedness and a skewed balance between local and global connectedness quantified with SW, all in EEG alpha band. In beta band, patients demonstrated above-normal resiliency, measured with assortativity coefficient, which also correlated with the frequency of PNES attacks. This interictal EEG phenotype may help improve differentiation between PNES and epilepsy. The results also suggest that local connectivity could be a target for therapeutic interventions in PNES. Selective modulation (strengthening) of local connectivity might improve the skewed balance between local and global connectivity and so prevent PNES events.