54 resultados para Sectoral horn

em Université de Lausanne, Switzerland


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In addition to functionally affected neuronal signaling pathways, altered axonal, dendritic, and synaptic morphology may contribute to hippocampal hyperexcitability in chronic mesial temporal lobe epilepsies (MTLE). The sclerotic hippocampus in Ammon's horn sclerosis (AHS)-associated MTLE, which shows segmental neuronal cell loss, axonal reorganization, and astrogliosis, would appear particularly susceptible to such changes. To characterize the cellular hippocampal pathology in MTLE, we have analyzed hilar neurons in surgical hippocampus specimens from patients with MTLE. Anatomically well-preserved hippocampal specimens from patients with AHS (n = 44) and from patients with focal temporal lesions (non-AHS; n = 20) were studied using confocal laser scanning microscopy (CFLSM) and electron microscopy (EM). Hippocampal samples from three tumor patients without chronic epilepsies and autopsy samples were used as controls. Using intracellular Lucifer Yellow injection and CFLSM, spiny pyramidal, multipolar, and mossy cells as well as non-spiny multipolar neurons have been identified as major hilar cell types in controls and lesion-associated MTLE specimens. In contrast, none of the hilar neurons from AHS specimens displayed a morphology reminiscent of mossy cells. In AHS, a major portion of the pyramidal and multipolar neurons showed extensive dendritic ramification and periodic nodular swellings of dendritic shafts. EM analysis confirmed the altered cellular morphology, with an accumulation of cytoskeletal filaments and increased numbers of mitochondria as the most prominent findings. To characterize cytoskeletal alterations in hilar neurons further, immunohistochemical reactions for neurofilament proteins (NFP), microtubule-associated proteins, and tau were performed. This analysis specifically identified large and atypical hilar neurons with an accumulation of low weight NFP. Our data demonstrate striking structural alterations in hilar neurons of patients with AHS compared with controls and non-sclerotic MTLE specimens. Such changes may develop during cellular reorganization in the epileptogenic hippocampus and are likely to contribute to the pathogenesis or maintenance of temporal lobe epilepsy.

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RESUME : La douleur neuropathique est le résultat d'une lésion ou d'un dysfonctionnement du système nerveux. Les symptômes qui suivent la douleur neuropathique sont sévères et leur traitement inefficace. Une meilleure approche thérapeutique peut être proposée en se basant sur les mécanismes pathologiques de la douleur neuropathique. Lors d'une lésion périphérique une douleur neuropathique peut se développer et affecter le territoire des nerfs lésés mais aussi les territoires adjacents des nerfs non-lésés. Une hyperexcitabilité des neurones apparaît au niveau des ganglions spinaux (DRG) et de la corne dorsale (DH) de la moelle épinière. Le but de ce travail consiste à mettre en évidence les modifications moléculaires associées aux nocicepteurs lésés et non-lésés au niveau des DRG et des laminae I et II de la corne dorsale, là où l'information nociceptive est intégrée. Pour étudier les changements moléculaires liés à la douleur neuropathique nous utilisons le modèle animal d'épargne du nerf sural (spared nerve injury model, SNI) une semaine après la lésion. Pour la sélection du tissu d'intérêt nous avons employé la technique de la microdissection au laser, afin de sélectionner une sous-population spécifique de cellules (notamment les nocicepteurs lésés ou non-lésés) mais également de prélever le tissu correspondant dans les laminae superficielles. Ce travail est couplé à l'analyse à large spectre du transcriptome par puce ADN (microarray). Par ailleurs, nous avons étudié les courants électriques et les propriétés biophysiques des canaux sodiques (Na,,ls) dans les neurones lésés et non-lésés des DRG. Aussi bien dans le système nerveux périphérique, entre les neurones lésés et non-lésés, qu'au niveau central avec les aires recevant les projections des nocicepteurs lésés ou non-lésés, l'analyse du transcriptome montre des différences de profil d'expression. En effet, nous avons constaté des changements transcriptionnels importants dans les nocicepteurs lésés (1561 gènes, > 1.5x et pairwise comparaison > 77%) ainsi que dans les laminae correspondantes (618 gènes), alors que ces modifications transcriptionelles sont mineures au niveau des nocicepteurs non-lésés (60 gènes), mais important dans leurs laminae de projection (459 gènes). Au niveau des nocicepteurs, en utilisant la classification par groupes fonctionnels (Gene Ontology), nous avons observé que plusieurs processus biologiques sont modifiés. Ainsi des fonctions telles que la traduction des signaux cellulaires, l'organisation du cytosquelette ainsi que les mécanismes de réponse au stress sont affectés. Par contre dans les neurones non-lésés seuls les processus biologiques liés au métabolisme et au développement sont modifiés. Au niveau de la corne dorsale de la moelle, nous avons observé des modifications importantes des processus immuno-inflammatoires dans l'aire affectée par les nerfs lésés et des changements associés à l'organisation et la transmission synaptique au niveau de l'aire des nerfs non-lésés. L'analyse approfondie des canaux sodiques a démontré plusieurs changements d'expression, principalement dans les neurones lésés. Les analyses fonctionnelles n'indiquent aucune différence entre les densités de courant tétrodotoxine-sensible (TTX-S) dans les neurones lésés et non-lésés même si les niveaux d'expression des ARNm des sous-unités TTX-S sont modifiés dans les neurones lésés. L'inactivation basale dépendante du voltage des canaux tétrodotoxine-insensible (TTX-R) est déplacée vers des potentiels positifs dans les cellules lésées et non-lésées. En revanche la vitesse de récupération des courants TTX-S et TTX-R après inactivation est accélérée dans les neurones lésés. Ces changements pourraient être à l'origine de l'altération de l'activité électrique des neurones sensoriels dans le contexte des douleurs neuropathiques. En résumé, ces résultats suggèrent l'existence de mécanismes différenciés affectant les neurones lésés et les neurones adjacents non-lésés lors de la mise en place la douleur neuropathique. De plus, les changements centraux au niveau de la moelle épinière qui surviennent après lésion sont probablement intégrés différemment selon la perception de signaux des neurones périphériques lésés ou non-lésés. En conclusion, ces modulations complexes et distinctes sont probablement des acteurs essentiels impliqués dans la genèse et la persistance des douleurs neuropathiques. ABSTRACT : Neuropathic pain (NP) results from damage or dysfunction of the peripheral or central nervous system. Symptoms associated with NP are severe and difficult to treat. Targeting NP mechanisms and their translation into symptoms may offer a better therapeutic approach.Hyperexcitability of the peripheral and central nervous system occurs in the dorsal root ganglia (DRG) and the dorsal horn (DH) of the spinal cord. We aimed to identify transcriptional variations in injured and in adjacent non-injured nociceptors as well as in corresponding laminae I and II of DH receiving their inputs.We investigated changes one week after the injury induced by the spared nerve injury model of NP. We employed the laser capture microdissection (LCM) for the procurement of specific cell-types (enrichment in nociceptors of injured/non-injured neurons) and laminae in combination with transcriptional analysis by microarray. In addition, we studied functionál properties and currents of sodium channels (Nav1s) in injured and neighboring non-injured DRG neurons.Microarray analysis at the periphery between injured and non-injured DRG neurons and centrally between the area of central projections from injured and non-injured neurons show significant and differential expression patterns. We reported changes in injured nociceptors (1561 genes, > 1.5 fold, >77% pairwise comparison) and in corresponding DH laminae (618 genes), while less modifications occurred in non-injured nociceptors (60 genes) and in corresponding DH laminae (459 genes). At the periphery, we observed by Gene Ontology the involvement of multiple biological processes in injured neurons such as signal transduction, cytoskeleton organization or stress responses. On contrast, functional overrepresentations in non-injured neurons were noted only in metabolic or developmentally related mechanisms. At the level of superficial laminae of the dorsal horn, we reported changes of immune and inflammatory processes in injured-related DH and changes associated with synaptic organization and transmission in DH corresponding to non-injured neurons. Further transcriptional analysis of Nav1s indicated several changes in injured neurons. Functional analyses of Nav1s have established no difference in tetrodotoxin-sensitive (TTX-S) current densities in both injured and non-injured neurons, despite changes in TTX-S Nav1s subunit mRNA levels. The tetrodotoxin-resistant (TTX-R) voltage dependence of steady state inactivation was shifted to more positive potentials in both injured and non-injured neurons, and the rate of recovery from inactivation of TTX-S and TTX-R currents was accelerated in injured neurons. These changes may lead to alterations in neuronal electrogenesis. Taken together, these findings suggest different mechanisms occurring in the injured neurons and the adjacent non-injured ones. Moreover, central changes after injury are probably driven in a different manner if they receive inputs from injured or non-injured neurons. Together, these distinct and complex modulations may contribute to NP.

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A cutaneous horn was observed close to the free margin of the inferior right eyelid in a 26-year-old-male patient. A minimal resection was primarily performed. Histopathologic study disclosed a precancerous keratosis. As the tumor had not been entirely excised, a complementary resection was performed secondarily to obtain the entire resection of the tumor.

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BACKGROUND: : Superselective ophthalmic artery chemotherapy (SOAC) has recently been proposed as an alternative to intravenous chemoreduction for advanced intraocular retinoblastoma. Preliminary results appear promising in terms of tumor control and eye conservation, but little is known regarding ocular toxicity and visual prognosis. In this study, we report on the vascular adverse effects observed in our initial cohort of 13 patients. METHODS: : The charts of 13 consecutive patients with retinoblastoma who received a total of 30 injections (up to 3 injections of a single agent per patient at 3-week interval) of melphalan (0.35 mg/kg) in the ophthalmic artery between November 2008 and June 2010 were retrospectively reviewed. RetCam fundus photography and fluorescein angiography were performed at presentation and before each injection. Vision was assessed at the latest visit. RESULTS: : Enucleation and external beam radiotherapy could be avoided in all cases but one, with a mean follow-up of 7 months. Sectoral choroidal occlusive vasculopathy leading to chorioretinal atrophy was observed temporally in 2 eyes (15%) 3 weeks to 6 weeks after the beginning of SOAC and retinal arteriolar emboli in 1 eye 2 weeks after injection. There was no stroke or other clinically significant systemic side effects except a perioperative transient spasm of the internal carotid artery in one patient. Vision ranged between 20/1600 and 20/32 depending on the status of the macula. CONCLUSION: : Superselective ophthalmic artery chemotherapy was effective in all patients with no stroke or other systemic vascular complications. Unlike intravenous chemoreduction, SOAC is associated with potentially sight-threatening adverse effects, such as severe chorioretinal atrophy secondary to subacute choroidal occlusive vasculopathy or central retinal artery embolism, not to mention the risk of ophthalmic artery obstruction, which was not observed in this series. Further analysis of the risks and benefits of SOAC will define its role within the therapeutic arsenal. Meanwhile, we suggest that SOAC should be given in one eye only and restricted to advanced cases of retinoblastoma, as an alternative to enucleation and/or external beam radiotherapy.

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The authors report a case of repetitive locking knee caused by a subluxation of the posterior horn of a normal lateral meniscus. The posterior horn was sutured to the posterior knee capsule and the athlete resumed complete sports activity 4 months after the surgery.

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BACKGROUND:: Superselective ophthalmic artery chemotherapy (SOAC) has recently been proposed as an alternative to intravenous chemoreduction for advanced intraocular retinoblastoma. Preliminary results appear promising in terms of tumor control and eye conservation, but little is known regarding ocular toxicity and visual prognosis. In this study, we report on the vascular adverse effects observed in our initial cohort of 13 patients. METHODS:: The charts of 13 consecutive patients with retinoblastoma who received a total of 30 injections (up to 3 injections of a single agent per patient at 3-week interval) of melphalan (0.35 mg/kg) in the ophthalmic artery between November 2008 and June 2010 were retrospectively reviewed. RetCam fundus photography and fluorescein angiography were performed at presentation and before each injection. Vision was assessed at the latest visit. RESULTS:: Enucleation and external beam radiotherapy could be avoided in all cases but one, with a mean follow-up of 7 months. Sectoral choroidal occlusive vasculopathy leading to chorioretinal atrophy was observed temporally in 2 eyes (15%) 3 weeks to 6 weeks after the beginning of SOAC and retinal arteriolar emboli in 1 eye 2 weeks after injection. There was no stroke or other clinically significant systemic side effects except a peroperative transient spasm of the internal carotid artery in one patient. Vision ranged between 20/1600 and 20/32 depending on the status of the macula. CONCLUSION:: Superselective ophthalmic artery chemotherapy was effective in all patients with no stroke or other systemic vascular complications. Unlike intravenous chemoreduction, SOAC is associated with potentially sight-threatening adverse effects, such as severe chorioretinal atrophy secondary to subacute choroidal occlusive vasculopathy or central retinal artery embolism, not to mention the risk of ophthalmic artery obstruction, which was not observed in this series. Further analysis of the risks and benefits of SOAC will define its role within the therapeutic arsenal. Meanwhile, we suggest that SOAC should be given in one eye only and restricted to advanced cases of retinoblastoma, as an alternative to enucleation and/or external beam radiotherapy.

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The global automobile industry is made up of very large corporations and their various subsidiaries containing different functions that create complex locational structures. The networks formed by the 19 largest automobile transnational corporations constitute an automobile "oligopoly" representing more than 90% (OICA, 2012) of the world's production. Since the mid-1990s, Central and Eastern European cities have become attractive for transnational corporations and particularly for the production functions in the automobile sector. This leads to a crucial question. Are strategic functions (such as R&D) within these networks also located in Central and Eastern Europe, or is the region still manufacturing-oriented in the automobile industry? This paper focuses on the patterns and the main factors influencing the role of some of these new central and Eastern European cities that have become integrated in the global value chain of the automobile industry. By analysing the various locations of the specialized functions within the corporations, this study aims to extend the research on global value chains (Gereffi and Korzeniewicz; 1994, Sturgeon, 2000; Krätke, 2014). The spatial patterns of the various functions and the ownerships networks of the automobile industry are constructed in order to identify the cities supporting it. In particular, the way that national metropolises bring their national territories into the globalization of the automobile industry is addressed. For example, are there some specific advantages of capital cities compared to cities that have less integration in globalization terms?

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PURPOSE: To assess the sensitivity and false positive rate (FPR) of neurological examination and somatosensory evoked potentials (SSEPs) to predict poor outcome in adult patients treated with therapeutic hypothermia after cardiopulmonary resuscitation (CPR). METHODS: MEDLINE and EMBASE were searched for cohort studies describing the association of clinical neurological examination or SSEPs after return of spontaneous circulation with neurological outcome. Poor outcome was defined as severe disability, vegetative state and death. Sensitivity and FPR were determined. RESULTS: A total of 1,153 patients from ten studies were included. The FPR of a bilaterally absent cortical N20 response of the SSEP could be calculated from nine studies including 492 patients. The SSEP had an FPR of 0.007 (confidence interval, CI, 0.001-0.047) to predict poor outcome. The Glasgow coma score (GCS) motor response was assessed in 811 patients from nine studies. A GCS motor score of 1-2 at 72 h had a high FPR of 0.21 (CI 0.08-0.43). Corneal reflex and pupillary reactivity at 72 h after the arrest were available in 429 and 566 patients, respectively. Bilaterally absent corneal reflexes had an FPR of 0.02 (CI 0.002-0.13). Bilaterally absent pupillary reflexes had an FPR of 0.004 (CI 0.001-0.03). CONCLUSIONS: At 72 h after the arrest the motor response to painful stimuli and the corneal reflexes are not a reliable tool for the early prediction of poor outcome in patients treated with hypothermia. The reliability of the pupillary response to light and the SSEP is comparable to that in patients not treated with hypothermia.

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Pediatric follicular lymphoma is a rare disease that differs genetically and clinically from its adult counterpart. With the exception of pediatric follicular lymphoma with IRF4-translocation, the genetic events associated with these lymphomas have not yet been defined. We applied array-comparative genomic hybridization and molecular inversion probe assay analyses to formalin-fixed paraffin-embedded tissues from 18 patients aged 18 years and under with IRF4 translocation negative follicular lymphoma. All evaluable cases lacked t(14;18). Only 6 of 16 evaluable cases displayed chromosomal imbalances with gains or amplifications of 6pter-p24.3 (including IRF4) and deletion and copy number neutral-loss of heterozygosity in 1p36 (including TNFRSF14) being most frequent. Sequencing of TNFRSF14 located in the minimal region of loss in 1p36.32 showed nine mutations in 7 cases from our series. Two subsets of pediatric follicular lymphoma were delineated according to the presence of molecular alterations, one with genomic aberrations associated with higher grade and/or diffuse large B-cell lymphoma component and more widespread disease, and another one lacking genetic alterations associated with more limited disease.

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BACKGROUND: Gene transfer to nociceptive neurons of the dorsal root ganglia (DRG) is a promising approach to dissect mechanisms of pain in rodents and is a potential therapeutic strategy for the treatment of persistent pain disorders such as neuropathic pain. A number of studies have demonstrated transduction of DRG neurons using herpes simplex virus, adenovirus and more recently, adeno-associated virus (AAV). Recombinant AAV are currently the gene transfer vehicles of choice for the nervous system and have several advantages over other vectors, including stable and safe gene expression. We have explored the capacity of recombinant AAV serotype 6 (rAAV2/6) to deliver genes to DRG neurons and characterized the transduction of nociceptors through five different routes of administration in mice. RESULTS: Direct injection of rAAV2/6 expressing green fluorescent protein (eGFP) into the sciatic nerve resulted in transduction of up to 30% eGFP-positive cells of L4 DRG neurons in a dose dependent manner. More than 90% of transduced cells were small and medium sized neurons (< 700 microm 2), predominantly colocalized with markers of nociceptive neurons, and had eGFP-positive central terminal fibers in the superficial lamina of the spinal cord dorsal horn. The efficiency and profile of transduction was independent of mouse genetic background. Intrathecal administration of rAAV2/6 gave the highest level of transduction (approximately 60%) and had a similar size profile and colocalization with nociceptive neurons. Intrathecal administration also transduced DRG neurons at cervical and thoracic levels and resulted in comparable levels of transduction in a mouse model for neuropathic pain. Subcutaneous and intramuscular delivery resulted in low levels of transduction in the L4 DRG. Likewise, delivery via tail vein injection resulted in relatively few eGFP-positive cells within the DRG, however, this transduction was observed at all vertebral levels and corresponded to large non-nociceptive cell types. CONCLUSION: We have found that rAAV2/6 is an efficient vector to deliver transgenes to nociceptive neurons in mice. Furthermore, the characterization of the transduction profile may facilitate gene transfer studies to dissect mechanisms behind neuropathic pain.

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(Résumé de l'ouvrage) This volume contains the papers presented at the 47th Colloquium Biblicum Lovaniense (Leuven, 1998). The general theme of the meeting was the unity of the Gospel of Luke and the Acts of the Apostles. Main papers on this topic were read by R.L. Brawley, J. Delobel, A. Denaux, J.A. Fitzmeyer, F.W. Horn, J. Kremer, A. Lindemann, O. Mainville, D. Marguerat, F. Neirynck, W. Radl, M. Rese, J. Taylor, C.M. Tuckett, and J. Verheyden. While a large majority of scholars agree that Luke intended his work to cover both the past and the continuing history of Jesus (Gospel and Acts), the essays also illustrate the complexities of this view on the unity of Luke-Acts when it comes to interpret the various aspects of Lukan theology, christology, pneumatology, and ecclesiology, the expansion of the Church in light of its Jewish origins, the genre of Luke-Acts, and the literary and stylistic means Luke used to make his work a unity. In total the volume includes some 40 papers, of which 24 are offered papers: L. Alexander, H. Baarlink, M. Bachmann, D. Bechard, T.L. Brodie, G.P. Carras, A. del Agua, C. Focant, G. Geiger, B.J. Koet, V. Koperski, D.P. Moessner, G. Oegema, J. Pichler, E. Plümacher, A. Puig i Tarrèch, U. Schmid, B. Schwank, N. Taylor, P.J. Tomson, S. Van den Eynde, S. Walton, G. Wasserberg, F. Wilk. This collection is an invaluable contribution to current discussions in Lukan study and to a nuanced understanding of the relationship between Luke's two volumes.