122 resultados para architectural recovery
Resumo:
The purposes of this study were to prospectively determine changes in rotator cuff strength before and after surgical shoulder stabilization by Bristow-Latarjet procedure and to better estimate time needed for rotator cuff strength recovery. 20 patients with recurrent anterior posttraumatic shoulder dislocation underwent internal (IR) and external (ER) rotator isokinetic evaluation before and 3, 6 and 21 months after Bristow-Latarjet surgery. In a seated position with 45° of shoulder abduction in the scapular plane, both shoulders were evaluated concentrically with a Con-Trex® isokinetic dynamometer at 180°∙s - 1, 120°∙s - 1 and 60°∙s - 1. 3 months post-surgery, IR and ER strength of the operated shoulder were significantly lower than before surgery ( - 28±20% for IR, - 17±17% for ER) (P<0.05). At 6 and 21 months post-surgery, IR and ER strength were comparable to strength before surgery; strength recovery is seen at 6 months post-surgery with long-term maintenance at 21 months. Given the weakness 3 months post-surgery, return to sports (including overhead and contact sports) should be discussed, and 6 months post-surgery may be a better point for an athlete to resume practicing sports. Isokinetic rotator cuff strength evaluation appears to be relevant in helping to determine the need of continuing strength rehabilitation. Pre-surgical evaluation contributes to the relevance of later comparisons.
Resumo:
In order to explore the magnitude and duration of the long-term residual effect of physical exercise, a mixed meal (55% CHO, 27% fat and 18% protein) was given to 10 young male volunteers on two occasions: after a 4-h resting period, and on the next day, 30 min after completion of a 3-h exercise at 50% VO2max. Energy expenditure and substrate utilization were determined by indirect calorimetry for 17 h after meal ingestion. The fuel mix oxidized after the meal was characterized by a greater contribution of lipid oxidation to total energy expenditure when the meal was ingested during the post-exercise period as compared with the meal ingested without previous exercise. During the night following the exercise, the stimulation of energy expenditure observed during the early recovery period gradually faded out. However, resting energy expenditure measured the next morning was significantly higher (+4.7%) than that measured without previous exercise. It is concluded that intense exercise stimulates both energy expenditure and lipid oxidation for a prolonged period.
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The aim of the study was to assess the clinical performance of the model combining areal bone mineral density (aBMD) at spine and microarchitecural texture (TBS) for the detection of the osteoporotic fracture. The Eastern European Study is a multicenter study (Serbia, Bulgaria, Romania and Ukraine) evaluating the role of TBS in routine clinical practice as a complement to aBMD. All scans were acquired on Hologic Discovery and GE Prodigy densitometers in a routine clinical manner. The additional clinical values of aBMD and TBS were analyzed using a two steps classification tree approach (aBMD followed by TBS tertiles) for all type of osteoporotic fracture (All-OP Fx). Sensitivity, specificity and accuracy of fracture detection as well as the Net Reclassification Index (NRI) were calculated. This study involves 1031 women subjects aged 45 and older recruited in east European countries. Clinical centers were cross-calibrated in terms of BMD and TBS. As expected, areal BMD (aBMD) at spine and TBS were only moderately correlated (r (2) = 0.19). Prevalence rate for All-OP Fx was 26 %. Subjects with fracture have significant lower TBS and aBMD than subjects without fracture (p < 0.01). TBS remains associated with the fracture even after adjustment for age and aBMD with an OR of 1.27 [1.07-1.51]. When using aBMD T-score of -2.5 and the lowest TBS tertile thresholds, both BMD and TBS were similar in terms of sensitivity (35 vs. 39 %), specificity (78 vs. 80 %) and accuracy (64 vs. 66 %). aBMD and TBS combination, induced a significant improvement in sensitivity (+28 %) and accuracy (+17 %) compared to aBMD alone whereas a moderate improvement was observed in terms of specificity (+9 %). The overall combination gain was 36 % as expressed using the NRI. aBMD and TBS combination decrease significantly the number of subjects needed to diagnose from 7 for aBMD alone to 2. In a multi-centre Eastern European cohort, we have shown that the use of TBS in addition to the aBMD permit to reclassified correctly more than one-third of the overall subjects. Furthermore, the number of subjects needed to diagnose fell to 2 subjects. Economical studies have to be performed to evaluate the gain induced by the use of TBS for the healthcare system.
Resumo:
Version abregée L'ischémie cérébrale est la troisième cause de mort dans les pays développés, et la maladie responsable des plus sérieux handicaps neurologiques. La compréhension des bases moléculaires et anatomiques de la récupération fonctionnelle après l'ischémie cérébrale est donc extrêmement importante et représente un domaine d'intérêt crucial pour la recherche fondamentale et clinique. Durant les deux dernières décennies, les chercheurs ont tenté de combattre les effets nocifs de l'ischémie cérébrale à l'aide de substances exogènes qui, bien que testées avec succès dans le domaine expérimental, ont montré un effet contradictoire dans l'application clinique. Une approche différente mais complémentaire est de stimuler des mécanismes intrinsèques de neuroprotection en utilisant le «modèle de préconditionnement» : une brève insulte protège contre des épisodes d'ischémie plus sévères à travers la stimulation de voies de signalisation endogènes qui augmentent la résistance à l'ischémie. Cette approche peut offrir des éléments importants pour clarifier les mécanismes endogènes de neuroprotection et fournir de nouvelles stratégies pour rendre les neurones et la glie plus résistants à l'attaque ischémique cérébrale. Dans un premier temps, nous avons donc étudié les mécanismes de neuroprotection intrinsèques stimulés par la thrombine, un neuroprotecteur «préconditionnant» dont on a montré, à l'aide de modèles expérimentaux in vitro et in vivo, qu'il réduit la mort neuronale. En appliquant une technique de microchirurgie pour induire une ischémie cérébrale transitoire chez la souris, nous avons montré que la thrombine peut stimuler les voies de signalisation intracellulaire médiées par MAPK et JNK par une approche moléculaire et l'analyse in vivo d'un inhibiteur spécifique de JNK (L JNK) .Nous avons également étudié l'impact de la thrombine sur la récupération fonctionnelle après une attaque et avons pu démontrer que ces mécanismes moléculaires peuvent améliorer la récupération motrice. La deuxième partie de cette étude des mécanismes de récupération après ischémie cérébrale est basée sur l'investigation des bases anatomiques de la plasticité des connections cérébrales, soit dans le modèle animal d'ischémie transitoire, soit chez l'homme. Selon des résultats précédemment publiés par divers groupes ,nous savons que des mécanismes de plasticité aboutissant à des degrés divers de récupération fonctionnelle sont mis enjeu après une lésion ischémique. Le résultat de cette réorganisation est une nouvelle architecture fonctionnelle et structurelle, qui varie individuellement selon l'anatomie de la lésion, l'âge du sujet et la chronicité de la lésion. Le succès de toute intervention thérapeutique dépendra donc de son interaction avec la nouvelle architecture anatomique. Pour cette raison, nous avons appliqué deux techniques de diffusion en résonance magnétique qui permettent de détecter les changements de microstructure cérébrale et de connexions anatomiques suite à une attaque : IRM par tenseur de diffusion (DT-IR1V) et IRM par spectre de diffusion (DSIRM). Grâce à la DT-IRM hautement sophistiquée, nous avons pu effectuer une étude de follow-up à long terme chez des souris ayant subi une ischémie cérébrale transitoire, qui a mis en évidence que les changements microstructurels dans l'infarctus ainsi que la modification des voies anatomiques sont corrélés à la récupération fonctionnelle. De plus, nous avons observé une réorganisation axonale dans des aires où l'on détecte une augmentation d'expression d'une protéine de plasticité exprimée dans le cône de croissance des axones (GAP-43). En appliquant la même technique, nous avons également effectué deux études, rétrospective et prospective, qui ont montré comment des paramètres obtenus avec DT-IRM peuvent monitorer la rapidité de récupération et mettre en évidence un changement structurel dans les voies impliquées dans les manifestations cliniques. Dans la dernière partie de ce travail, nous avons décrit la manière dont la DS-IRM peut être appliquée dans le domaine expérimental et clinique pour étudier la plasticité cérébrale après ischémie. Abstract Ischemic stroke is the third leading cause of death in developed countries and the disease responsible for the most serious long-term neurological disability. Understanding molecular and anatomical basis of stroke recovery is, therefore, extremely important and represents a major field of interest for basic and clinical research. Over the past 2 decades, much attention has focused on counteracting noxious effect of the ischemic insult with exogenous substances (oxygen radical scavengers, AMPA and NMDA receptor antagonists, MMP inhibitors etc) which were successfully tested in the experimental field -but which turned out to have controversial effects in clinical trials. A different but complementary approach to address ischemia pathophysiology and treatment options is to stimulate and investigate intrinsic mechanisms of neuroprotection using the "preconditioning effect": applying a brief insult protects against subsequent prolonged and detrimental ischemic episodes, by up-regulating powerful endogenous pathways that increase resistance to injury. We believe that this approach might offer an important insight into the molecular mechanisms responsible for endogenous neuroprotection. In addition, results from preconditioning model experiment may provide new strategies for making brain cells "naturally" more resistant to ischemic injury and accelerate their rate of functional recovery. In the first part of this work, we investigated down-stream mechanisms of neuroprotection induced by thrombin, a well known neuroprotectant which has been demonstrated to reduce stroke-induced cell death in vitro and in vivo experimental models. Using microsurgery to induce transient brain ischemia in mice, we showed that thrombin can stimulate both MAPK and JNK intracellular pathways through a molecular biology approach and an in vivo analysis of a specific kinase inhibitor (L JNK1). We also studied thrombin's impact on functional recovery demonstrating that these molecular mechanisms could enhance post-stroke motor outcome. The second part of this study is based on investigating the anatomical basis underlying connectivity remodeling, leading to functional improvement after stroke. To do this, we used both a mouse model of experimental ischemia and human subjects with stroke. It is known from previous data published in literature, that the brain adapts to damage in a way that attempts to preserve motor function. The result of this reorganization is a new functional and structural architecture, which will vary from patient to patient depending on the anatomy of the damage, the biological age of the patient and the chronicity of the lesion. The success of any given therapeutic intervention will depend on how well it interacts with this new architecture. For this reason, we applied diffusion magnetic resonance techniques able to detect micro-structural and connectivity changes following an ischemic lesion: diffusion tensor MRI (DT-MRI) and diffusion spectrum MRI (DS-MRI). Using DT-MRI, we performed along-term follow up study of stroke mice which showed how diffusion changes in the stroke region and fiber tract remodeling is correlating with stroke recovery. In addition, axonal reorganization is shown in areas of increased plasticity related protein expression (GAP 43, growth axonal cone related protein). Applying the same technique, we then performed a retrospective and a prospective study in humans demonstrating how specific DTI parameters could help to monitor the speed of recovery and show longitudinal changes in damaged tracts involved in clinical symptoms. Finally, in the last part of this study we showed how DS-MRI could be applied both to experimental and human stroke and which perspectives it can open to further investigate post stroke plasticity.
Resumo:
La présente thèse s'inscrit dans la continuité de la publication des fouilles menées de 1986 à 2002 sur le site de la villa gallo-romaine d'Orbe-Boscéaz/VD par l'Institut d'archéologie et des sciences de l'antiquité de l'Université de Lausanne (URBA I, à paraître dans les Cahiers d'archéologie romande). Elle constitue l'analyse approfondie du corpus des peintures murales fragmentaires -succinctement présentées dans URBA I - appartenant à la pars urbana qui succéda, entre 161 et 180 apr. J.-C, à un édifice plus petit du Ier s. de notre ère -dont les peintures sont publiées dans l'ouvrage sus-mentionné. N'ayant subi que de très rares modifications, cette pars urbana de caractère palatial forme un "ensemble clos" autorisant une analyse globale de la conception architecturale et décorative voulue par le bâtisseur ou son commanditaire. Le corpus pictural, composé d'un matériel assez ingrat remplissant quelque 600 cagettes de stockage, offre de ce fait l'intérêt d'une grande homogénéité chronologique et reflète la cohérence et l'unité de la décoration peinte d'origine. Le travail de discrimination et de remontage des ensembles a permet d'individualiser au moins 220 décors et revêtements muraux; l'ensemble des hypothèses de restitution des peintures donne ainsi une image minimale de l'environnement pictural de la pars urbana. Ce corpus pictural n'est toutefois que l'une des composantes du programme décoratif, aussi l'analyse de ses caractéristiques est-elle confrontée à celle des autres composantes ornementales (architecture, placages de marbres et surtout le remarquable ensemble des mosaïques qui fait la célébrité du site). La conjugaison des divers éléments et leur répartition au sein d'un plan bien connu et très symétrique orientent sur les choix décoratifs majeurs, et permettent sinon de reconstituer, tout au moins d'approcher la conception du programme architectural et décoratif voulu par le commanditaire ou son architecte; ce programme, comme fréquemment, reflète le statut du commanditaire, le met évidemment en scène et tient un discours sur la villa, adressé tant aux habitants qu'aux visiteurs. On trouvera dans le travail six chapitres formant l'essentiel de l'exploitation du corpus pictural urbigène. Le premier chapitre est introductif, et présente dans ses grandes lignes la pars urbana de Boscéaz comme cadre de référence. Il est suivi par un état des lieux des peintures murales retrouvées sur le site, abordant leur répartition, leur état de conservation et la méthodologie adoptée pour leur traitement comme leur étude (chapitre 2). Le chapitre 3 constitue l'étude technique des enduits peints. Il réunit toutes les observations que l'on peut faire sur les techniques de réalisation des peinture murales, de la préparation et la pose des mortiers de support aux tours de main des peintres pour le rendu d'un motif. Ce chapitre s'inscrit dans la perspective, appliquée à Boscéaz, d'études marquantes comme celles sur les techniques de préparation des parois (Allag /Barbet 1972, Barbet 1995) sur l'identification des pigments (PACT 17, 1985, Béarat 1997, Colloque de Fribourg 1997) et sur l'analyse des mortiers (Coutelas 2003). Suit le catalogue des peintures, basé sur une sélection de 3414 plaques remontées et fragments (chapitre 4) : il propose une description rigoureuse et systématique des motifs, ainsi que leur analyse stylistique qui apporte les éléments comparatifs permettant la compréhension du matériel, et justifiant son interprétation, voire sa restitution. Les décors y sont présentés par local de découverte; un paragraphe introductif réunit les données de fouille et des informations sur le local ou le prélèvement des enduits, et donne le nombre et la détermination des décors retrouvés. Chacun d'eux fait l'objet d'une notice regroupant: une détermination par le mortier de support (le tectorium); les observations techniques diverses; la description, la restitution le cas échéant, et l'analyse stylistique. Cette dernière privilégie les comparaisons locales, en Suisse d'abord puis dans les pays limitrophes de façon à mettre en évidence les liens plausibles entre certains sites et les éventuels indices d'une production régionale. La documentation graphique qui accompagne chaque décor dans le volume d'illustrations est constituée avant tout des planches photographiques des fragments à l'échelle 1:3, accompagnés le cas échéant de dessins au trait justifiant la lecture des motifs. Ceux-ci permettent la reconstitution idéale
Resumo:
A new Early Triassic marine fauna is described from the Central Oman Mountains. The fauna is Griesbachian in age, on the basis of abundant conodonts and ammonoids, and was deposited in an oxygenated seamount setting off the Arabian platform margin. It is the first Griesbachian assemblage from a well-oxygenated marine setting and thus provides a test for the hypothesis that widespread anoxia prevented rapid recovery. The earliest Griesbachian (parvus zone) contains a low-diversity benthic fauna dominated by the bivalves Promyalina and Claraia. A similar level of recovery characterizes the immediate postextinction interval worldwide. However, the middle upper Griesbachian sedimentary rocks (isarcica and catinata zones) contain an incredibly diverse benthic fauna of bivalves, gastropods, articulate brachiopods, a new undescribed crinoid, echinoids, and ostracods. This fauna is more diverse and ecologically complex than the typical middle to late Griesbachian faunas described from oxygen-restricted settings worldwide. The level of postextinction recovery observed in the Oman fauna is not recorded elsewhere until the Spathian. These data support the hypothesis that the apparent delay in recovery after the end-Permian extinction event was due to widespread and prolonged benthic oxygen restriction: in the absence of anoxia, marine recovery is much faster.
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The remarkable plasticity of their architecture allows plants to adjust growth to the environment and to overcome adverse conditions. Two examples of environmental stresses that drastically affect shoot development are imminent shade and high temperature. Plants in crowded environments and plants in elevated ambient temperature display very similar phenotypic adaptations of elongated hypocotyls in seedlings and elevated and elongated leaves at later developmental stages. The comparable growth responses to shade and high temperature are partly regulated through shared signaling pathways, of which the phytohormone auxin and the phytochrome interacting factors (PIFs) are important components. During both shade- and temperature-induced elongation growth auxin biosynthesis and signaling are upregulated in a PIF-dependent manner. In this review we will discuss recent progress in our understanding of how auxin mediates architectural adaptations to shade and high temperature.
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Laparoscopy is one of the cornerstones in the surgical revolution and transformed outcome and recovery for various surgical procedures. Even if these changes were widely accepted for basic interventions, like appendectomies and cholecystectomies, laparoscopy still remains challenged for more advanced operations in many aspects. Despite these discussion, there is an overwhelming acceptance in the surgical community that laparoscopy did transform the recovery for several abdominal procedures. The importance of improved peri-operative patient management and its influence on outcome started to become a focus of attention 20 years ago and is now increasingly spreading, as shown by the incoming volume of data on this topic. The enhanced recovery after surgery (ERAS) concept incorporates simple measures of general management, and requires multidisciplinary collaboration from hospital staff as well as the patient and the relatives. Several studies have demonstrated a significant decrease in postoperative complication rate, length of hospital stay and reduced overall cost. The key elements of success are fluid restriction, a functioning epidural and preoperative carbohydrate intake. With the expansion of laparoscopic techniques, ERAS increasingly incorporates laparoscopic patients, especially in colorectal surgery. However, the precise impact of laparoscopy on ERAS is still not clearly defined. Increasing evidence suggests that laparoscopy itself is an additional ERAS item that should be considered as routine where feasible in order to obtain the best surgical outcomes.
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The term water stress refers to the effects of low water availability on microbial growth and physiology. Water availability has been proposed as a major constraint for the use of microorganisms in contaminated sites with the purpose of bioremediation. Sphingomonas wittichii RW1 is a bacterium capable of degrading the xenobiotic compounds dibenzofuran and dibenzo-p-dioxin, and has potential to be used for targeted bioremediation. The aim of the current work was to identify genes implicated in water stress in RW1 by means of transposon mutagenesis and mutant growth experiments. Conditions of low water potential were mimicked by adding NaCl to the growth media. Three different mutant selection or separation method were tested which, however recovered different mutants. Recovered transposon mutants with poorer growth under salt-induced water stress carried insertions in genes involved in proline and glutamate biosynthesis, and further in a gene putatively involved in aromatic compound catabolism. Transposon mutants growing poorer on medium with lowered water potential also included ones that had insertions in genes involved in more general functions such as transcriptional regulation, elongation factor, cell division protein, RNA polymerase β or an aconitase.
Resumo:
The Munc13 gene family encodes molecules located at the synaptic active zone that regulate the reliability of synapses to encode information over a wide range of frequencies in response to action potentials. In the CNS, proteins of the Munc13 family are critical in regulating neurotransmitter release and synaptic plasticity. Although Munc13-1 is essential for synaptic transmission, it is paradoxical that Munc13-2 and Munc13-3 are functionally dispensable at some synapses, although their loss in other synapses leads to increases in frequency-dependent facilitation. We addressed this issue at the calyx of Held synapse, a giant glutamatergic synapse that we found to express all these Munc13 isoforms. We studied their roles in the regulation of synaptic transmission and their impact on the reliability of information transfer. Through detailed electrophysiological analyses of Munc13-2, Munc13-3, and Munc13-2-3 knock-out and wild-type mice, we report that the combined loss of Munc13-2 and Munc13-3 led to an increase in the rate of calcium-dependent recovery and a change in kinetics of release of the readily releasable pool. Furthermore, viral-mediated overexpression of a dominant-negative form of Munc13-1 at the calyx demonstrated that these effects are Munc13-1 dependent. Quantitative immunohistochemistry using Munc13-fluorescent protein knock-in mice revealed that Munc13-1 is the most highly expressed Munc13 isoform at the calyx and the only one highly colocalized with Bassoon at the active zone. Based on these data, we conclude that Munc13-2 and Munc13-3 isoforms limit the ability of Munc13-1 to regulate calcium-dependent replenishment of readily releasable pool and slow pool to fast pool conversion in central synapses.