5 resultados para Ligament croisé antérieur

em Aston University Research Archive


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Ossification of the posterior longitudinal ligament (OPLL) is a significantly critical pathology that can eventually cause serious myelopathy. Ossification commences in the vertebral posterior longitudinal ligaments, and intensifies and spreads with the progression of the disease, resulting in osseous projections and compression of the spinal cord. However, the paucity of histological studies the underlying mechanisms of calcification and ossification processes remain obscure. The pathological process could be simulated in the ossifying process of the ligament in mutant spinal hyperostotic mouse (twy/twy). The aim of this study is to observe that enlargement of the nucleus pulposus followed by herniation, disruption and regenerative proliferation of annulus fibrosus cartilaginous tissues participated in the initiation of ossification of the posterior longitudinal ligament of twy/twy mice.

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This article looks at the conditions under which a construction has an own interpretation. Interpreting the first proposal of the type constructions modalisante I think that P is considered. It is shown that these interpretations can be fully explained by parsing of the sequence I think than a subordinated, resulting in a set of undesirable consequences. The ability to handle this sequence as a construction in the theoretical that gives this constructionnelle grammar concept is envisaged to assess the relationships between form, meaning sense, compositionnalité and invariant. Cet article s'intéresse aux conditions suivant lesquelles une construction possède une interprétation qui lui est propre. L'interprétation modalisante de la première proposition des constructions du type Je crois que P est considérée. Il est montré que ces interprétations ne peuvent être pleinement expliquées par l'analyse syntaxique faisant de la séquence Je crois que une subordonnée, qui entraîne un ensemble de conséquences indésirables. La possibilité de traiter cette séquence comme une construction dans le sens théorique que donne à cette notion la Grammaire constructionnelle est envisagée, permettant d'apprécier les rapports entre forme, sens, compositionnalité et invariant.

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De nombreuses langues du monde grammaticalisent les formes lexicales itive (aller) et ventive (venir) en auxiliaires temporels. Si ce fait a été abondamment décrit dans des langues particulières, on ne dispose pas d’une étude contrastive des deux tours, ce que nous proposons d’entreprendre dans la présente communication, sur quelques langues, A partir des premiers constats suivants : - la forme itive est plus fréquemment grammaticalisée que la forme ventive : en anglais p. ex. seul go est grammaticalisé ; - si le plus souvent l’itif s’est grammaticalisé dans l’expression de l’imminence-ultériorité (le train va partir) et le ventif dans celle de la récence (le train vient de partir), ce n’est pas toujours le cas : en catalan, anar + inf. est un prétérit (el tren va marchar : ‘le train est parti’), et actualise donc le procès non comme ultérieur mais comme antérieur ; - certaines langues, comme le français, ont développé sur ces auxiliaires, outre les effets de sens temporel d’imminence-ultériorité pour l’itif et de récence pour le ventif, un effet de sens d’extraordinaire, qui peut être signifié aussi bien par l’un que par l’autre tour (il va pas / vient pas me dire) - l’imminence-ultériorité sur l’itif et la récence sur le ventif souffrent des restrictions temporelles, plus accusées pour le premier : en francais p. ex., aller, dans cet effet de sens, se conjugue aux seuls présent et imparfait (le train va / allait / * irait / *est allé partir) ; venir admet en plus le futur et le conditionnel (le train vient/ venait/viendra/ viendrait/ *est venu de partir). On se propose (i) d’expliciter les différents éléments de l’asymétrie dans la grammaticalisation des deux formes itive et ventive dans les langues retenues (anglais, catalan, espagnol, français, italien, portugais), et (ii) de formuler une hypothèse explicative de ces faits hétérogènes.

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Cervical compressive myelopathy is the most serious complication of cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL) and the most frequent cause of spinal cord dysfunction. There is little information on the exact pathophysiological mechanism responsible for the progressive loss of neural tissue in the spinal cord of such patients. In this study, we used the spinal hyperostotic mouse (twy/twy) as a suitable model of human spondylosis, and OPLL to investigate the cellular and molecular changes in the spinal cord. Mutant twy/twy mouse developed ossification of the ligamentum flavum at C2-C3 and exhibited progressive paralysis.

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Background:Cervical compressive myelopathy, e.g. due to spondylosis or ossification of the posterior longitudinal ligament is a common cause of spinal cord dysfunction. Although human pathological studies have reported neuronal loss and demyelination in the chronically compressed spinal cord, little is known about the mechanisms involved. In particular, the neuroinflammatory processes that are thought to underlie the condition are poorly understood. The present study assessed the localized prevalence of activated M1 and M2 microglia/macrophages in twy/twy mice that develop spontaneous cervical spinal cord compression, as a model of human disease.Methods:Inflammatory cells and cytokines were assessed in compressed lesions of the spinal cords in 12-, 18- and 24-weeks old twy/twy mice by immunohistochemical, immunoblot and flow cytometric analysis. Computed tomography and standard histology confirmed a progressive spinal cord compression through the spontaneously development of an impinging calcified mass.Results:The prevalence of CD11b-positive cells, in the compressed spinal cord increased over time with a concurrent decrease in neurons. The CD11b-positive cell population was initially formed of arginase-1- and CD206-positive M2 microglia/macrophages, which later shifted towards iNOS- and CD16/32-positive M1 microglia/macrophages. There was a transient increase in levels of T helper 2 (Th2) cytokines at 18 weeks, whereas levels of Th1 cytokines as well as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and macrophage antigen (Mac) -2 progressively increased.Conclusions:Spinal cord compression was associated with a temporal M2 microglia/macrophage response, which may act as a possible repair or neuroprotective mechanism. However, the persistence of the neural insult also associated with persistent expression of Th1 cytokines and increased prevalence of activated M1 microglia/macrophages, which may lead to neuronal loss and demyelination despite the presence of neurotrophic factors. This understanding of the aetiopathology of chronic spinal cord compression is of importance in the development of new treatment targets in human disease. © 2013 Hirai et al.