INTRODUÇÃO: A autorregulação cerebral representa um dos mecanismos fisiopatológicos incertos na hemorragia intracerebral espontânea, cujo comprometimento pode influenciar no resultado prognóstico e terapêutico. O objetivo deste trabalho é avaliar a autorregulação cerebral dinâmica em modelo suíno de hemorragia intracerebral espontânea através do índice de reatividade pressórica cerebrovascular e determinar a eficácia das intervenções clínicas e cirúrgicas. MÉTODOS: Foram estudados 21 suínos híbridos machos com idade de 3 meses. O modelo experimental simulou o efeito expansivo de uma hemorragia intracerebral espontânea de grande volume quando comparado ao cérebro humano. Foram avaliados volumes de expansão diferentes, distribuídos em três grupos com sete suínos cada. O protocolo anestésico incluiu uma monitoração hemodinâmica invasiva associada a preservação da autorregulação cerebral. Os experimentos foram submetidos a monitoração neurológica multimodal e divididos em 5 fases. O índice de reatividade pressórica cerebrovascular estimou a autorregulacão cerebral durante todas as fases, sendo as três primeiras sem intervenções terapêuticas e as duas últimas para avaliar a eficácia das intervenções salina hipertônica e cirurgia. RESULTADOS: Os grupos avaliados foram homogêneos e sem diferença estatística quanto ao comprometimento da autorregulação cerebral comparando os diferentes volumes e tempos de compressão durante as duas primeiras horas da expansão do volume intracraniano. O comprometimento do índice de reatividade pressórica cerebrovascular ocorreu em alguns experimentos influenciando nas fases de tratamento subsequentes, salina hipertônica e cirurgia. CONCLUSÕES: Volumes expansivos elevados podem comprometer a autorregulação cerebral dinâmica e apresentar desfecho terapêutico desfavorável. A intervenção clínica e cirúrgica tem benefício nos experimentos com preservação do índice de reatividade pressórica cerebrovascular / INTRODUCTION: Cerebral autoregulation represents one of the uncertain pathophysiological mechanisms in spontaneous intracerebral hemorrhage, whose impairment may influence prognostic and therapeutic outcome. The aim of this study was to evaluate the dynamic cerebral autoregulation in the swine model of spontaneous intracerebral hemorrhage through the cerebrovascular reactivity index and to determine the efficacy of clinical and surgical interventions. METHODS: Twenty-one male hybrid pigs aged 3 months were studied. The experimental model simulated the expansive effect of a large intracerebral hemorrhage when compared to the human brain. Different volumes were evaluated, distributed in three groups with seven pigs each. Each experiment was divided in five phases. The anesthetic protocol included invasive hemodynamic monitoring associated with the preservation of cerebral autoregulation. Multimodallity monitoring was realised in all experiments. The cerebrovascular reactivity index estimated the cerebral autoregulation during all phases. The first three phases were without therapeutic interventions, and the last two phases were with therapeutic intervention of hypertonic saline solution and neurosurgery respectively. RESULTS: The evaluated groups were homogeneous and without statistical difference regarding the impairment of the cerebral autoregulation comparing different volumes and compression times during the first two hours of the intracranial volume expansion. CONCLUSIONS: Elevated expansive volumes may compromise dynamic cerebral autoregulation and have unfavorable therapeutic outcome. Clinical and surgical intervention had benefit in the experiments with preservation of cerebrovascular reactivity index

Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2018-02-27T12:45:52Z No. of bitstreams: 1 ADRIANA BATISTA DE SOUZA KOIDE.pdf: 2381385 bytes, checksum: 72f9eb08c1959a9f627afb877d36b4fd (MD5) / Made available in DSpace on 2018-02-27T12:45:52Z (GMT). No. of bitstreams: 1 ADRIANA BATISTA DE SOUZA KOIDE.pdf: 2381385 bytes, checksum: 72f9eb08c1959a9f627afb877d36b4fd (MD5) Previous issue date: 2016-12-15 / Pontif?cia Universidade Cat?lica de Campinas ? PUC Campinas / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Children's literature and education are instances that complete the development of small child. Through children's literature it?s possible to promote learning that child will carry on for life. Considering this background, a descriptive research with a qualitative approach is presented from the theoretical perspectives of Piaget, Bandura and Feuerstein. The overall aim is to understand how to use children's literature in order to promote self-regulation strategies with children from two to six years without losing its enjoyment space. Research instruments were organized to meet the following specific aims: i) to plan, develop and evaluate a continued training for teachers involved, during 2015 with the theme children's literature, self-regulation and learning mediation; ii) to understand the selection criterion of children's books by educators and which pedagogical practices members of the continued formation considered the most appropriate to promote self-regulation and fruition from the children's literature; iii) to socialize with team the most relevant practices and experiences indicated by participants; iv) to analyze what was reported by teachers on children's literature as fruition and as a means for develop self-regulation skills in children from two to six years; v) to verify if it?s there is harmony between children's literature as a formative art and as pedagogical use in unison on early childhood education. Twelve teachers who worked in multigrade classes from kindergarten serving 354 children aged 2 to 6 years were study participants. The instruments used were field diary records of continued formation, researcher and participating teachers, observations of practices and interviews. For the understanding of the empirical material were used the content analysis. The results obteined show that the small child can self-regulate thoughts, feelings and actions by means of children's literature since it is inserted in a learning process mediated by a teacher who develop activities guided to fruition, for reflection and critical thinking. This analyzis indicates that mediated dialogue after the planned intervention for harmony between pleasure and learning was the most assertive activity to promote self-regulation with children of all investigated groups. In this sense, we emphasize that teacher education was ssential for the developement of research, preponderating the fact that it would not be possible to exercise the teaching profession with fullness in the context studied if there was no initial or continuous training knowledge. The conclusion is that the incentive for new researches and teacher training on the chosen subject is urgently needed, so that you can advance studies to invest in the capacity of small children and in the training of teachers for childhood, a barely explored field in academia. / Literatura infantil e educa??o s?o inst?ncias que se completam na forma??o da crian?a pequena. Por meio da literatura infantil ? poss?vel promover aprendizagens que a crian?a levar? consigo para toda a vida. Nesse contexto, trazemos uma pesquisa descritiva, com abordagem qualitativa, a partir das perspectivas te?ricas de Piaget, Bandura e Feuerstein. O objetivo geral do estudo consiste em compreender como utilizar a literatura infantil para promover estrat?gias da autorregula??o com crian?as de dois a seis anos, sem que a mesma perca seu espa?o de frui??o. Os instrumentos de pesquisa foram organizados para atender aos seguintes objetivos espec?ficos: i) planejar, desenvolver e avaliar uma forma??o continuada para os educadores envolvidos, no decorrer do ano de 2015, tendo como tem?tica a literatura infantil, a autorregula??o e a media??o do professor; ii) compreender crit?rios de escolha dos livros infantis pelos educadores e quais pr?ticas pedag?gicas os integrantes da forma??o continuada consideram como as mais adequadas para promover a autorregula??o e a frui??o; iii) socializar entre a equipe as pr?ticas e experi?ncias mais relevantes, indicadas pelos participantes; iv) analisar o que relatam as professoras sobre a literatura infantil como frui??o e como meio para desenvolver as compet?ncias da autorregula??o em crian?as de dois a seis anos no contexto observado e v) verificar se ? poss?vel a harmonia entre a literatura infantil como arte formativa e como meio pedag?gico na Educa??o Infantil. Participaram do estudo 12 professoras que atuavam em classes multisseriadas da Educa??o Infantil, atendendo 354 crian?as de 2 a 6 anos. Os instrumentos utilizados foram registros do di?rio de campo da forma??o continuada, da pesquisadora e das professoras participantes, observa??es de pr?ticas e entrevistas. Para a compreens?o do material emp?rico utilizou-se a an?lise de conte?do. Os resultados obtidos demonstram que a crian?a pequena consegue, por meio da literatura infantil, autorregular pensamentos, sentimentos e a??es, desde que inserida em uma aprendizagem mediada por um professor que tenha os conhecimentos necess?rios para desenvolver atividades abertas para a frui??o, para a reflex?o e para o pensamento cr?tico. Nossas an?lises indicam que o di?logo mediado, depois da interven??o planejada para a harmonia entre deleite e aprendizagem, foi a pr?tica pedag?gica mais assertiva para promover a autorregula??o, com crian?as de todas as turmas investigadas. Nesse sentido, salientamos que a forma??o docente foi essencial para o desenvolvimento da pesquisa, preponderando o fato de que n?o seria poss?vel o exerc?cio da profiss?o docente com plenitude no contexto estudado se n?o houvesse para isso um conhecimento formativo inicial ou continuado. Conclu?mos que o incentivo em novas pesquisas e em forma??es docentes sobre a tem?tica escolhida se fazem urgentemente necess?rios, para que seja poss?vel avan?ar em estudos que invistam na capacidade das crian?as pequenas e na forma??o de professores para a inf?ncia, campos ainda pouco explorados no meio acad?mico.

The thesis on topic "Development of Metacognitive Thinking of Pupils by RWCT Practices" asks a research question: "How does RWCT develop the metacognitive thinking of pupils at elementary school and what are the outputs?" The aim is to find out the possibilities and the limits of the pupils' metacognition using the RWCT (Reading and Writing for Critical Thinking). In the theoretical part, this thesis deals with the definition of metacognition, relation among metacognition and autoregulation, metacognition and self-reflection, metacognition and teaching, and last but not least the RWCT procedures in terms of the objectives of the program itself and the objectives of the RVP ZV (Framework Educational Program for Basic Education). The possibilities of using the RWCT procedures in connection with the development of metacognitive thinking of pupils at elementary school level were examined using the action research that took place in a fifth grade, where RWCT procedures are being regularly used. During searching answer on the research question is used analysation and description on basis of participated observation, pupils' products, written reflection and pupils' self-reflection. Furthermore with non-structural interview. From action research results that RWCT practices initiate discussion between...

This research aimed to investigate the democratic aspects of procedural negotiation clause recently inserted into the Brazilian legal system by Article 190 of Law n. 13,105, of March 16, 2015 (New Code of Civil Procedure). The rule allows, in certain situations, that the parties negotiate on procedural rules, before or during the process in which demands law allows autocomposição. The rule, in effect, by giving autorregramento of powers between the parties in the development process, eases some publicists aspects of the Brazilian legal system. It is observed, therefore a paradigmatic breakthrough that is inclined to empower parts. Without forgetting its controversial aspects, we intend to analyze the institute as a democratic instrument under the cooperative process. From this perspective, the work is divided into three chapters. In the first chapter, we analyze the methodological stages of civil procedure in order to rescue some marginalized traditions throughout modernity to then rethink a new grammar for contemporary jurisdiction. In the second chapter, we point out a correlation between the normative model of deliberative-procedural democracy (Habermas) and the cooperative process and traced the main assumptions of a democratic legal proceedings. Were their assumptions that served to analyze aspects of the general principle of negotiating share in the third chapter of the work. / A presente pesquisa pretendeu investigar os aspectos democráticos da cláusula geral de negociação processual recentemente inserida no ordenamento jurídico brasileiro pelo artigo 190 da Lei n. 13.105, de 16 de março de 2015 (Novo Código de Processo Civil). A regra permite, em determinadas situações, que as partes negociem sobre regras processuais, antes ou durante o processo, em demandas cujo direito admita autocomposição. A norma, com efeito, ao conferir poderes de autorregramento às partes no desenvolvimento do processo, flexibiliza alguns aspectos publicistas do ordenamento processual brasileiro. Percebe-se, deste modo, um movimento de ruptura paradigmática que se inclina a empoderar as partes. Sem olvidar os seus aspectos controvertidos, pretende-se analisar o instituto enquanto um instrumento democrático no âmbito do processo cooperativo. Nessa perspectiva, o trabalho divide-se em três capítulos. No primeiro capítulo, analisamos as fases metodológicas do processo civil no intuito de resgatar algumas tradições marginalizadas ao longo da modernidade para, em seguida, repensar uma nova gramática para a jurisdição contemporânea. No segundo capítulo, apontamos uma correlação entre o modelo normativo de democracia deliberativo-procedimental (Habermas) e o processo cooperativo e traçamos os principais pressupostos de um processo jurisdicional democrático. Foram essas as premissas que serviram para analisar os aspectos da cláusula geral de negocia ação no terceiro capítulo do trabalho.

INTRODUÇÃO: A autorregulação cerebral representa um dos mecanismos fisiopatológicos incertos na hemorragia intracerebral espontânea, cujo comprometimento pode influenciar no resultado prognóstico e terapêutico. O objetivo deste trabalho é avaliar a autorregulação cerebral dinâmica em modelo suíno de hemorragia intracerebral espontânea através do índice de reatividade pressórica cerebrovascular e determinar a eficácia das intervenções clínicas e cirúrgicas. MÉTODOS: Foram estudados 21 suínos híbridos machos com idade de 3 meses. O modelo experimental simulou o efeito expansivo de uma hemorragia intracerebral espontânea de grande volume quando comparado ao cérebro humano. Foram avaliados volumes de expansão diferentes, distribuídos em três grupos com sete suínos cada. O protocolo anestésico incluiu uma monitoração hemodinâmica invasiva associada a preservação da autorregulação cerebral. Os experimentos foram submetidos a monitoração neurológica multimodal e divididos em 5 fases. O índice de reatividade pressórica cerebrovascular estimou a autorregulacão cerebral durante todas as fases, sendo as três primeiras sem intervenções terapêuticas e as duas últimas para avaliar a eficácia das intervenções salina hipertônica e cirurgia. RESULTADOS: Os grupos avaliados foram homogêneos e sem diferença estatística quanto ao comprometimento da autorregulação cerebral comparando os diferentes volumes e tempos de compressão durante as duas primeiras horas da expansão do volume intracraniano. O comprometimento do índice de reatividade pressórica cerebrovascular ocorreu em alguns experimentos influenciando nas fases de tratamento subsequentes, salina hipertônica e cirurgia. CONCLUSÕES: Volumes expansivos elevados podem comprometer a autorregulação cerebral dinâmica e apresentar desfecho terapêutico desfavorável. A intervenção clínica e cirúrgica tem benefício nos experimentos com preservação do índice de reatividade pressórica cerebrovascular / INTRODUCTION: Cerebral autoregulation represents one of the uncertain pathophysiological mechanisms in spontaneous intracerebral hemorrhage, whose impairment may influence prognostic and therapeutic outcome. The aim of this study was to evaluate the dynamic cerebral autoregulation in the swine model of spontaneous intracerebral hemorrhage through the cerebrovascular reactivity index and to determine the efficacy of clinical and surgical interventions. METHODS: Twenty-one male hybrid pigs aged 3 months were studied. The experimental model simulated the expansive effect of a large intracerebral hemorrhage when compared to the human brain. Different volumes were evaluated, distributed in three groups with seven pigs each. Each experiment was divided in five phases. The anesthetic protocol included invasive hemodynamic monitoring associated with the preservation of cerebral autoregulation. Multimodallity monitoring was realised in all experiments. The cerebrovascular reactivity index estimated the cerebral autoregulation during all phases. The first three phases were without therapeutic interventions, and the last two phases were with therapeutic intervention of hypertonic saline solution and neurosurgery respectively. RESULTS: The evaluated groups were homogeneous and without statistical difference regarding the impairment of the cerebral autoregulation comparing different volumes and compression times during the first two hours of the intracranial volume expansion. CONCLUSIONS: Elevated expansive volumes may compromise dynamic cerebral autoregulation and have unfavorable therapeutic outcome. Clinical and surgical intervention had benefit in the experiments with preservation of cerebrovascular reactivity index

This graduation thesis, entitled "Results of libel in press in the relation to the relevant moral rights especially in the area of private law in the Czech Republic" examines press interference into relevant moral rights. The first chapter describes the historical foundations of personal rights protection, as well as their international and European connections. The second chapter discusses the power of media, and the means used for its maintenance and strengthening. In the third chapter, an outline of motivations for publication of news press, which balance between righteousness and libel. In the fourth chapter, an assessment of the clash between freedom of speech and protection of privacy, which are categories guaranteed in the Charter of Rights and Freedoms. The content of the fifth chapter is fundamental because it provides a thorough analysis of the law which governs personal rights, with a focus on the civil code, press law and procedural rules. The sixth chapter brings sight of rules established by autoregulation. It deals with self- censorship, the journalist's code of ethics, self-controlling authorities and so on. In the seventh chapter, the author examines the motivation behind submitting an accusation for the breach of personal rights. The motivation can be a real and legitimate defence...

TDP-43 est une protéine de liaison aux acides nucléiques qui joue un rôle essentiel dans le métabolisme de l'ARN. À l'état physiologique, un contrôle strict des niveaux d’expression de cette protéine est critique pour la fonction et la survie cellulaire. Une boucle d'autorégulation négative est à la base de ce contrôle du taux intracellulaire de TDP-43. Laquelle a été identifiée comme le constituant principal des inclusions observées chez une majorité des patients atteints de Sclérose Latérale Amyotrophique (SLA) ou de Dégénérescence Lobaire Fronto-Temporale (DLFT). A ce jour, plus de 50 mutations faux-sensdu gène TARDBP/TDP-43 ont été décrites chez des patients DLFT/SLA, démontrant le rôle clé de TDP-43 dans ces pathologies neurodégénératives. Notons cependant que les conséquences fonctionnelles de ces mutations ne sont pas complètement déterminées. Plusieurs études suggèrent qu’une élévation des niveaux d’accumulation de TDP-43 pourraitparticiper aux mécanismes physiopathologiques. La modulation du cycle de production de TDP-43 pourrait donc constituer une nouvelle stratégie thérapeutique. Ce travail de recherche avait donc pour principal objectif d’identifier des modulateurs génétiques de la production de TDP-43 en utilisant un nouveau modèle de drosophile transgénique mimant les principales étapes d’autorégulation de TDP-43. Nous avons ainsi pu montrer que la modulation des niveaux d’expression de la protéine TCERG1 et de plusieurs facteurs d'épissage, parmi lesquels SRSF1, SRSF3 et SF3B1, influe sur les niveaux de production deTDP-43. Nous avons également montré que la présence des mutations DLFT/SLA n’altère pas la capacité de la protéine à s’autoréguler. / TDP-43 is a DNA/RNA binding protein that plays an important role in RNA metabolism. In the physiological state, strict control of its expression levels is critical for cell function and survival. TDP-43 expression is tightly regulated through an autoregulatory negative feedback loop. This protein has been identified as the principal component of the inclusions observed in a majority of patients with Amyotrophic Lateral Sclerosis (ALS) or FrontoTemporal Lobar Degeneration (FTLD). To date, more than 50 missense mutations of the TARDBP / TDP-43 gene have been described in FTLD / ALS patients, demonstrating the key role of TDP-43 in these neurodegenerative pathologies. However, the functional consequences of TDP-43 mutations are not completely determined. Several studies suggest that high accumulation levels of TDP-43 may participate in pathophysiological mechanisms. The modulation of the production cycle of TDP-43 may therefore provide a new therapeutic strategy. The main goal of this research project was to identify genetic modulators of TDP-43 production by using a novel transgenic Drosophila model mimicking main steps of TDP-43 the autoregulatory mechanism. We identified several splicing factors, including SF2, Rbp1 and Sf3b1, as genetic modulators of TDP-43 production. We have also shown that modulation of TCERG1 expression levels affect TDP-43 production levels in flies. Finally, we found that FTLD/ALSlinked TDP-43 mutations do not alter TDP-43’s ability to self-regulate its expression and consequently of the homeostasis of TDP-43 protein levels.

Chronic kidney disease (CKD) is defined as glomerular filtration rate (GFR) less than 60 mL/min/1.73 m2 for 3 months and is characterized by progressive loss of renal function. The second leading cause of CKD is hypertension. More than half of CKD patients also suffer from hypertension. Arteries and arterioles adjust to the fluctuations in the systematic blood pressure through a mechanism called autoregulation. In the kidneys, autoregulation protects the delicate glomeruli capillaries from high blood pressure and occurs through myogenic constriction (MC). MC refers to contraction of arterioles in response to an increase in the blood pressure. Chronically hypertensive individuals and animal models have an enhanced MC, leading to minimal renal injury despite their elevated blood pressure. Experimental and clinical evidence point to a role for the MC in the pathogenesis of the CKD, however, the mechanism through which preglomerular arterial MC contributes to CKD has not been fully elucidated. This thesis showed that augmented MC in chronically hypertensive animal models was due to increased thromboxane A2 prostaglandin that was not released from the endothelium (Chapter 2). Nevertheless, inhibiting MC while also reducing the blood pressure prevented salt-induced renal injury even though the blood pressure was still not normalized compared to the normotensive controls (Chapter 3). The resulting improvement in renal structure and function could be attributed to the reduction in the blood pressure, albumin, and uromodulin (UMOD) excretion (Chapter 3). UMOD is a kidney-specific glycoprotein that, based on a genome-wide association study have the strongest association to CKD (Chapter 3). Comparing two CKD hypertensive animal models further revealed that CKD progression was independent of the blood pressure and strongly associated with UMOD excretion levels (Chapter 4). Collectively, the data discussed in this thesis demonstrates potential therapeutic targets in CKD hypertensive animal models. / Dissertation / Doctor of Philosophy (PhD)

Il est généralement accepté que les lits vasculaires oculaires auraient la faculté d’autoréguler leur apport sanguin afin de contrebalancer les variations de pression de perfusion oculaire (PPO). Plusieurs études ont tenté d’évaluer ce mécanisme en mesurant les effets d’une variation de la PPO - induite par un exercice ou par une augmentation de la pression intra-oculaire (PIO) à l’aide d’une suction sclérale - sur le débit sanguin oculaire (DSO). Or, les méthodes de mesure du DSO utilisées jusqu'à maintenant présentent de nombreux désavantages et limites, ce qui rend difficile leur usage clinique. De récents développements dans le domaine des investigations non-invasives des paramètres sanguins oculaires proposent un modèle capable de mesurer en temps réel la concentration en oxygène, un autre paramètre important du métabolisme rétinien. Dans le cadre de la présente étude, ce nouveau modèle est utilisé afin de mesurer les effets d’un effort physique dynamique sur la concentration d’oxygène dans les capillaires de la tête du nerf optique (COTNO) de sujets jeunes et en santé. Six jeunes hommes non fumeurs ont participé à l’étude. L’effort physique dynamique consistait en une séance de bicyclette stationnaire de 15 minutes menant à une augmentation du pouls à 160 battements par minute. La COTNO était mesurée avant et immédiatement après la séance d’exercice. La pression artérielle (PA) et la PIO étaient mesurées ponctuellement alors que le pouls et la saturation sanguine en oxygène (SpO2) au niveau digital étaient mesurés tout au long de l’expérience. L’effort physique a entrainé une réduction de la PIO chez tous les sujets, une réduction de la COTNO chez tous les sujets sauf un tandis que la SpO2 demeura constante chez tous les sujets. Une corrélation quadratique entre les variations de la PIO et de la COTNO a pu être notée. Ces résultats suggèrent une corrélation directe entre les variations de la COTNO et celles de la PPO et de la PA. Les résultats de la présente étude suggèrent que les variations de la COTNO chez un sujet en santé suite à un effort physique dynamique pourraient représenter sa capacité à compenser un tel effort. De plus, les changements métaboliques sanguins induits par l’effort physique dynamique pourraient représenter une cause commune aux variations de la PIO et de la COTNO. / It is generally accepted that ocular vascular beds have the ability to autoregulate their blood flow to counter balance the variations in the ocular perfusion pressure (OPP). Many studies have tried to evaluate this mechanism by quantifying the effects of a variation in OPP on the ocular blood flow (OBF). This was induced by either exercise or scleral suction which increases intra-ocular pressure (IOP). However, the methods used for these measurements have many disadvantages and limitations, which deters their clinical use. Recent developments in the field of non-invasive investigation of ocular blood parameters propose a model for the measurement, in real-time, of oxygen concentration in the blood streams, another important parameter of the retinal metabolism. In the present study, this new model is used to evaluate the effects of dynamic physical efforts on the blood oxygenation in the optic nerve head capillary structures (BOONH) in young healthy subjects. Six non-smoking young men participated in the study. 15-minute sessions of stationary bicycle leading to a heart rate of 160bpm were performed as dynamic physical effort. The BOONH was measured before and immediately after the exercise. The blood pressure (BP) and the IOP were measured periodically while the heart rate and the oxygen saturation in blood (SpO2) were measured in a finger throughout the exercise. The physical effort led to a reduction of the IOP in all subjects, a decrease in the BOONH in all but one subjects and a constant SpO2 in all subjects. A quadratic correlation was observed between the variations in IOP and in BOONH. These results suggest a direct correlation between the variations in BOONH and those of the OPP and the BP. The results of the present study suggest that the variations in BOONH in a healthy subject following a physical dynamic effort could indicate his/her capacity to compensate for such an effort. Moreover, the metabolic changes in the blood due to physical dynamic efforts could be a common cause of the variations in IOP and BOONH.

Il est généralement accepté que les lits vasculaires oculaires auraient la faculté d’autoréguler leur apport sanguin afin de contrebalancer les variations de pression de perfusion oculaire (PPO). Plusieurs études ont tenté d’évaluer ce mécanisme en mesurant les effets d’une variation de la PPO - induite par un exercice ou par une augmentation de la pression intra-oculaire (PIO) à l’aide d’une suction sclérale - sur le débit sanguin oculaire (DSO). Or, les méthodes de mesure du DSO utilisées jusqu'à maintenant présentent de nombreux désavantages et limites, ce qui rend difficile leur usage clinique. De récents développements dans le domaine des investigations non-invasives des paramètres sanguins oculaires proposent un modèle capable de mesurer en temps réel la concentration en oxygène, un autre paramètre important du métabolisme rétinien. Dans le cadre de la présente étude, ce nouveau modèle est utilisé afin de mesurer les effets d’un effort physique dynamique sur la concentration d’oxygène dans les capillaires de la tête du nerf optique (COTNO) de sujets jeunes et en santé. Six jeunes hommes non fumeurs ont participé à l’étude. L’effort physique dynamique consistait en une séance de bicyclette stationnaire de 15 minutes menant à une augmentation du pouls à 160 battements par minute. La COTNO était mesurée avant et immédiatement après la séance d’exercice. La pression artérielle (PA) et la PIO étaient mesurées ponctuellement alors que le pouls et la saturation sanguine en oxygène (SpO2) au niveau digital étaient mesurés tout au long de l’expérience. L’effort physique a entrainé une réduction de la PIO chez tous les sujets, une réduction de la COTNO chez tous les sujets sauf un tandis que la SpO2 demeura constante chez tous les sujets. Une corrélation quadratique entre les variations de la PIO et de la COTNO a pu être notée. Ces résultats suggèrent une corrélation directe entre les variations de la COTNO et celles de la PPO et de la PA. Les résultats de la présente étude suggèrent que les variations de la COTNO chez un sujet en santé suite à un effort physique dynamique pourraient représenter sa capacité à compenser un tel effort. De plus, les changements métaboliques sanguins induits par l’effort physique dynamique pourraient représenter une cause commune aux variations de la PIO et de la COTNO. / It is generally accepted that ocular vascular beds have the ability to autoregulate their blood flow to counter balance the variations in the ocular perfusion pressure (OPP). Many studies have tried to evaluate this mechanism by quantifying the effects of a variation in OPP on the ocular blood flow (OBF). This was induced by either exercise or scleral suction which increases intra-ocular pressure (IOP). However, the methods used for these measurements have many disadvantages and limitations, which deters their clinical use. Recent developments in the field of non-invasive investigation of ocular blood parameters propose a model for the measurement, in real-time, of oxygen concentration in the blood streams, another important parameter of the retinal metabolism. In the present study, this new model is used to evaluate the effects of dynamic physical efforts on the blood oxygenation in the optic nerve head capillary structures (BOONH) in young healthy subjects. Six non-smoking young men participated in the study. 15-minute sessions of stationary bicycle leading to a heart rate of 160bpm were performed as dynamic physical effort. The BOONH was measured before and immediately after the exercise. The blood pressure (BP) and the IOP were measured periodically while the heart rate and the oxygen saturation in blood (SpO2) were measured in a finger throughout the exercise. The physical effort led to a reduction of the IOP in all subjects, a decrease in the BOONH in all but one subjects and a constant SpO2 in all subjects. A quadratic correlation was observed between the variations in IOP and in BOONH. These results suggest a direct correlation between the variations in BOONH and those of the OPP and the BP. The results of the present study suggest that the variations in BOONH in a healthy subject following a physical dynamic effort could indicate his/her capacity to compensate for such an effort. Moreover, the metabolic changes in the blood due to physical dynamic efforts could be a common cause of the variations in IOP and BOONH.