At the turn of second and third century Catechetic school in Alexandria comes with new motions. It reevaluates the system of Platon and stoical philosophy and opens new chance to the CHristian paradigm. Naturally it becomes evident in the philosophy of education. Clement´s three degrees way MYÉSIS-TELÉTÉ-EPOPTEIA can be inspired nowadays. One of the method is the using of EIKÓN and dialog.

Neuropeptide W-23 (NPW23) and neuropeptide W-30 (NPW30) are 23- and 30-amino acid peptides recently isolated from the porcine hypothalamus. Immunohistochemical studies using a rabbit polyclonal antiserum against the rat NPW23 peptide revealed a limited distribution in the rat brain. NPW23-immunoreactive (irNPW) cells were detected in the paraventricular nucleus (PVH), mainly in the parvocellular division, supraoptic nucleus (SO), accessory neurosecretory nuclei, dorsal and lateral hypothalamic areas, perifornical nucleus, arcuate nucleus, and anterior and posterior pituitary; whereas, irNPW fibers were noted in the PVH and SO, retrochiasmatic nucleus, dorsal and lateral hypothalamic areas, median eminence, amygdala, and posterior pituitary. The pattern of distribution of irNPW in the hypothalamus corroborates a possible role of NPW on prolactin release and feeding behavior reported by others.

Distribution of the novel peptide beacon in the hypothalamus of Sprague-Dawley rats was examined by immunohistochemical methods. Beacon-immunoreactive (irBC) neurons were found in the paraventricular, supraoptic, and accessory neurosecretory nuclei, and intensely labeled fibers in the median eminence and infundibulo-pituitary stalk. Scattered cells and/or fibers were noted in the suprachiasmatic nucleus, arcuate nucleus, retrochiasmatic area, lateral and medial preoptic area, as well as anterior and lateral hypothalamic area. The wide distribution of irBC in the hypothalamus of Sprague-Dawley rats suggests that the peptide may influence, in addition to a proposed role in feeding, a multitude of biological activities associated with the hypothalamic-pituitary axis.

No description available.

No description available.

Female reproductive senescence is widespread among mammalian species, but menopause is limited to species with menstrual cycles. While hormonal changes at menopause have profound impacts in the lives of women at middle age, the complex mechanisms underlying this process remain obscure. All three levels of the hypothalamic-pituitary-gonadal (HPG) axis are involved in reproductive aging, and evidence highlights a critical role for the dysregulation of gonadotropin-releasing hormone (GnRH) neurons, the hypothalamic cells that drive reproductive function. To investigate neuroendocrine mechanisms that may initiate and perpetuate reproductive decline at each step in the transition to acyclicity, I utilized an ovarian-intact middle-aged female rat model of natural reproductive senescence. These studies focused on three hypothalamic nuclei that are known to control GnRH activity: the anteroventral periventricular nucleus (AVPV), the site of positive hormone feedback onto GnRH neurons; the arcuate nucleus (ARC), the site of negative feedback; and the median eminence (ME), the site of GnRH release, with the following specific aims: 1) Characterize neuroendocrine gene and protein expression in female rats throughout the natural transition to acyclicity; 2) Determine the effects of chronic N-methyl-D-asparate receptor subunit 2b (NMDAR-NR2b) inhibition in acyclic females; and 3) Examine neuroendocrine gene expression during premature reproductive senescence after perturbation of the HPG axis. The results of these studies identified novel molecular and cellular changes with age and reproductive cycle status in the ARC and ME, two regions that are underappreciated for their roles in reproductive senescence. Surprisingly, few molecular targets were identified in the AVPV, a region that is much better-studied in this context. In the ME and ARC, I found changes in transcription factors and evidence of altered hormone feedback via changes in sex steroid hormone receptors and enzyme expression with reproductive aging. I also discovered decreased expression of genes for the excitatory neuropeptides, kisspeptin and neurokinin B, as well as decreased percentage of kisspeptin immunoreactive cells and their co-expression with estrogen receptor alpha in the ARC. And finally, in the ME, neurotrophic factor expression was changed with age, and the presence and phosphorylation state of the NR2b subunit of the NMDA receptor contributes to a greater inhibitory tone with acyclicity. Together these studies have identified novel pathways, especially in the ARC and ME, that are related to reproductive decline. Furthermore, changes in the hypothalamic neural and glial network of neurotransmitters, neuropeptides, hormone receptors and other transcription factors are likely contributing to altered responses to hormonal feedback and decreased excitatory drive for GnRH release. / text

Este estudo avaliou por meio da Ressonância Magnética a intensidade de sinal do tecido retrodiscal associando a anatomia da eminência articular, derrame articular e deslocamento do disco com e sem redução. Para isto, foram analisadas imagens por RM de 48 ATM de 24 indivíduos sintomáticos, sendo 19 (79,2%) do gênero feminino e 5 (20,8%) do gênero masculino. Considerando o posicionamento sagital, cerca de 5 (10,4%) das articulações eram normais, 23 (47,9%) das articulações eram DDCR e 20 (41,7%) eram DDSR. Para a forma da eminência articular, cerca de 15 (31,3%) das articulações foram classificadas como tendo formato de caixa, 12 (25,0%) foram classificadas como sigmoide, 10 (20,8%) como aplainada e 11 (22,9%) das articulações foram classificadas como deformada. A maioria das articulações apresentaram derrame cerca de 32 (66,7%). Das articulações com DDSR, 16 (51,6%) apresentaram derrame e as com DDCR 15 (48,4%). As articulações com DDCR apresentaram 9 (39,15) em forma de caixa, 6 (26,1%) como sigmóide, 3 (13,0%) estavam aplainada e 5 (21,7%) deformadas; as ATM com DDSR apresentaram 5 (25,5%) como caixa, 4 (20,0%) como sigmóide, 6 (30,0%) aplainadas e 5 (25,5%) deformadas. A forma da eminência articular não está relacionada ao posicionamento sagital (p=0,520). O posicionamento sagital do disco não está relacionado à presença de derrame (p=0,281). A intensidade de sinal do TR foi estatisticamente menor no posicionamento sagital DDCR, quando comparado ao posicionamento sagital DDSR (p=0,016). Houve uma tendência da intensidade do sinal do tecido retrodiscal ser maior nas articulações com derrame quando comparado às sem derrame (p=0,065). Não houve relação entre posicionamento sagital do disco e derrame. E por fim, o presente estudo não conseguiu estabelecer uma relação entre o sinal do tecido retrodiscal e eminência articular (p=0,159). / This study evaluated MR signal intensity of retrodiscal tissue associated with articular eminence morphology, joint effusion status, and disc displacement with and without reduction (DDwR and DDwoR, respectively). Forty-eight TMJ MR images of 24 symptomatic subjects (19 females and 5 males) were analyzed. For the sagittal position, 5 (10.4%) joints were normal, 23 (47.9%) showed DDwR and 20 (41.7%) DDwoR. Regarding articular eminence morphology, 15 (31.3%) joints were classified as box-shaped, 12 (25.0%) as sigmoid, 10 (20.8%) flattened and 11 (22.9%) deformed. The majority of TMJs (32 or 66.7%) showed effusion. Sixteen (51.6%) of the TMJs with DDwoR had effusion versus 15 (48.4%) of those with DDDwR. Of TMJs with DDwR, 9 (39.1%) were box-shaped, 6 (26.1%) sigmoid, 3 (13.0%) flattened and 5 (21.7%) deformed. Among joints with DDwoR, 5 (25.5%) were boxshaped, 4 (20.0%) sigmoid, 6 (30.0%) flattened and 5 (25.5%) deformed. As a conclusion, articular eminence shape was not related to sagittal position of the disk (p = 0.520). Sagittal position of the disk was not related to presence of effusion (p = 0.281). Signal intensity of retrodiscal tissue (RT) was statistically lower in the DDwR sagittal position than in DDwoR cases (p = 0.016). There was a tendency for higher RT signal intensity in joints with effusion versus those without effusion (p = 0.065). No relationship between sagittal position of the disc and effusion was observed. No relationship between signal intensity of retrodiscal tissue and shape of articular eminence was identified (p = 0.159).

O objetivo deste estudo é avaliar a correspondência anatômica entre a eminência arqueada e o canal semicircular superior na superfície da fossa craniana média. Este estudo transversal descritivo foi realizado em um hospital terciário. Setenta e cinco pacientes consecutivos (150 lados), submetidos à tomografia computadorizada de alta resolução dos ossos temporais, foram analisados por dois autores. Para cada exame, a relação anatômica entre a eminência arqueada e o canal semicircular superior foi classificada como coincidente ou não coincidente. Distâncias entre os parâmetros anatômicos de maior utilidade na cirurgia da fossa média e prevalência de deiscência do canal semicircular superior também foram estudadas. A eminência arqueada foi coincidente com o canal semicircular superior em apenas 31.3% dos casos. Não foi possível identificar a eminência arqueada em 33 exames (22.0%). Deiscência do canal semicircular superior foi encontrada em cinco casos (3.3%). Poucos milímetros separaram a cóclea do canal semicircular superior. As medidas secundárias foram caracterizadas por ampla variabilidade. A eminência arqueada não se sobrepõe sistematicamente ao canal semicircular superior e não deve ser usada rotineiramente como uma referência para a localização dessa estrutura. / The objective of this study is to evaluate the anatomical coincidence between the arcuate eminence and the superior semicircular canal at the middle cranial fossa surface. This crosssectional descriptive study was performed at a tertiary hospital. Seventy-five consecutive patients (150 sides) who underwent bilateral high-resolution temporal bone computed tomography scans were analyzed by two authors. In each scan, the anatomical relationship between the arcuate eminence and the superior semicircular canal was classified as coincident or non-coincident. Distances between the most applicable anatomical landmarks for middle cranial fossa surgery and the prevalence of superior semicircular canal dehiscence were also studied. The arcuate eminence matched the semicircular canal in only 31.3% of cases. It was impossible to identify the arcuate eminence in 33 scans (22.0%). Semicircular canal dehiscence was found in 5 cases (3.3%). A few millimeters separated the cochea from SSC; secondary measurements were characterized by broad variability. The arcuate eminence does not systematically overlie the superior semicircular canal and should not be routinely used as a reference for reaching this structure in the context of middle fossa surgery.

L'hypothalamus médiobasal contient de nombreux noyaux régulant l'homéostasie énergétique en réponse aux variations des signaux métaboliques périphériques, telles que les nutriments et les hormones, l'informant de l'état énergétique de l'individu. Parmi ces noyaux, le noyau arqué hypothalamique (NA) est considéré comme le noyau clé de la régulation de la prise alimentaire. En effet, il est capable de recevoir et d'intégrer les informations métaboliques périphériques, pour ensuite les relayer vers les autres noyaux hypothalamiques régulant la prise alimentaire. Dans ce contexte, l'accès des molécules périphériques au NA est une étape importante dans la régulation de la prise alimentaire. L'organisation des interfaces sang/cerveau à ce niveau est d'ailleurs très particulière, suggérant une régulation spécifique de l'accès des molécules périphériques vers le NA. En effet, deux types de vaisseaux sont retrouvés dans cette région cérébrale : 1- les vaisseaux de la barrière hématoencéphalique (BHE) dans le NA et 2- les vaisseaux fenêtrés dans l'éminence médiane (EM), un organe circumventriculaire (OCV) adjacent au NA. Alors que les vaisseaux de la BHE présentent des propriétés de barrière et régulent les échanges sang/NA, les vaisseaux de l'EM possèdent de nombreuses fenestrations facilitant les échanges sang/EM. Ces deux types de vaisseaux ont la particularité d'être contactés par des cellules épendymaires hautement spécialisées formant le bas du 3ème ventricule. Ces cellules, appelées " tanycytes ", expriment des protéines de jonctions serrées suggérant leur participation à la régulation des échanges sang/cerveau dans cette région cérébrale. En effet, des études menées au sein du laboratoire ont montré que les tanycytes de l'EM, contactant les vaisseaux fenêtrés, expriment des protéines de jonctions serrées (JS) organisées en ceinture continue autour de leur pôle apical. Ces JS créent ainsi un épendyme étanche qui limite les échanges EM/LCR. A l'inverse, les tanycytes du NA, contactant les vaisseaux de la BHE, expriment des protéines de JS non organisées en leur pôle apical. L'épendyme du NA est ainsi perméable et favorise les échanges LCR/NA. Le but de mon travail de thèse a donc été de comprendre, en prenant en compte tous ces éléments -c'est-à-dire la présence de vaisseaux fenêtrés, de vaisseaux de la BHE et des tanycytes -, comment est organisé l'accès des signaux métaboliques périphériques vers le NA et si cet accès pouvait être modulé afin de contrôler l'homéostasie énergétique. Nos expériences ont montré que, chez la souris mâle adulte, une glucopénie induite par le jeûne ou par le 2-desoxyglucose induisait une réorganisation structurale des vaisseaux et de l'épendyme au niveau de l'EM et du NA, modifiant ainsi les échanges sang/cerveau. En effet, chez ces souris, nous avons observé une augmentation du nombre de vaisseaux fenêtrés au niveau de l'EM et du NA, ainsi qu'une réorganisation fonctionnelle des protéines de JS au niveau du ventricule : les tanycytes du NA, contactant des vaisseaux fenêtrés à présent, réorganisent leurs protéines de jonctions serrées (JS) afin d'assurer l'homéostasie cérébrale. Ces réorganisations induisent alors un meilleur accès des molécules périphériques vers le NA. De plus, nos résultats ont montré que cette plasticité est induite par le VEGF-A, produit localement par les tanycytes. En effet, la neutralisation du VEGF-A bloque la plasticité de l'EM/NA induite par l'hypoglycémie et perturbent la réponse physiologique hyperphagique lors de la réalimentation. Enfin, nos données supplémentaires indiquent que cette plasticité de l'EM/NA est conservée dans différents modèles alimentaires et se produit également au cours de la journée, suggérant son implication dans le contrôle circadien du comportement alimentaire.

O objetivo deste estudo é avaliar a correspondência anatômica entre a eminência arqueada e o canal semicircular superior na superfície da fossa craniana média. Este estudo transversal descritivo foi realizado em um hospital terciário. Setenta e cinco pacientes consecutivos (150 lados), submetidos à tomografia computadorizada de alta resolução dos ossos temporais, foram analisados por dois autores. Para cada exame, a relação anatômica entre a eminência arqueada e o canal semicircular superior foi classificada como coincidente ou não coincidente. Distâncias entre os parâmetros anatômicos de maior utilidade na cirurgia da fossa média e prevalência de deiscência do canal semicircular superior também foram estudadas. A eminência arqueada foi coincidente com o canal semicircular superior em apenas 31.3% dos casos. Não foi possível identificar a eminência arqueada em 33 exames (22.0%). Deiscência do canal semicircular superior foi encontrada em cinco casos (3.3%). Poucos milímetros separaram a cóclea do canal semicircular superior. As medidas secundárias foram caracterizadas por ampla variabilidade. A eminência arqueada não se sobrepõe sistematicamente ao canal semicircular superior e não deve ser usada rotineiramente como uma referência para a localização dessa estrutura. / The objective of this study is to evaluate the anatomical coincidence between the arcuate eminence and the superior semicircular canal at the middle cranial fossa surface. This crosssectional descriptive study was performed at a tertiary hospital. Seventy-five consecutive patients (150 sides) who underwent bilateral high-resolution temporal bone computed tomography scans were analyzed by two authors. In each scan, the anatomical relationship between the arcuate eminence and the superior semicircular canal was classified as coincident or non-coincident. Distances between the most applicable anatomical landmarks for middle cranial fossa surgery and the prevalence of superior semicircular canal dehiscence were also studied. The arcuate eminence matched the semicircular canal in only 31.3% of cases. It was impossible to identify the arcuate eminence in 33 scans (22.0%). Semicircular canal dehiscence was found in 5 cases (3.3%). A few millimeters separated the cochea from SSC; secondary measurements were characterized by broad variability. The arcuate eminence does not systematically overlie the superior semicircular canal and should not be routinely used as a reference for reaching this structure in the context of middle fossa surgery.