Objetivos: Avaliar a evolução e as complicações dos doentes que sobreviveram a ferimentos cardíacos, atendidos no Pronto-Socorro Municipal 28 de Agosto e Hospital Pronto-Socorro Dr. João Lúcio Pereira Machado, em Manaus, no período de janeiro de 1998 a junho de 2006. Métodos: Foi realizada uma busca de prontuários dos doentes atendidos nos dois prontossocorros, nos quais durante a toracotomia exploradora evidenciou-se o ferimento cardíaco. Os sobreviventes que retornaram ao ambulatório foram avaliados prospectivamente por meio de eletrocardiograma e ecocardiograma, para averiguar a morfologia e a funcionalidade do coração. Foi preenchido um protocolo com registro dos dados dos doentes, tais como: idade, sexo, mecanismo de trauma, complicações intra e pós-operatórias, dentre outras variáveis. Resultados: A população de referência totalizou 100 doentes, dos quais 95% eram homens, 69% entre 20 e 30 anos; 81% das lesões foram por arma branca, sendo que em 78% delas, a entrada se encontrava no precórdio; 41% das lesões acometeram o ventrículo direito (VD) e 38% acometeram o ventrículo esquerdo (VE); em 48% dos casos foi realizada toracotomia ântero-lateral esquerda. A sobrevivência foi de 72%. A população de estudo foi composta por 25 doentes que retornaram ao ambulatório e foram avaliados prospectivamente por meio de eletrocardiograma e ecocardiograma. Das 33 alterações no ecocardiograma (ECO), sete doentes (28%) tinham insuficiência mitral, enquanto nove (36%) não tinham alterações. Das 45 alterações no eletrocardiograma (ECG), oito doentes (32%) tinham taquicardia sinusal, enquanto seis (24%) não tinham alterações. Não houve efeito do tempo no resultado do ECO (p=0,5323) ou do ECG (p=0,6596). Das alterações detectadas no ECO, três (21,4%) foram devidas a lesões grau IV (em VD) e 11 (78,7%) devidas a lesões grau V (em VE) (p=0,048). Das 12 alterações detectadas no ECG, três (25%) relacionaram-se a lesões grau IV e nove (75%) relacionaram-se a lesões grau V (p=0,226). Conclusões: Aproximadamente um terço dos sobreviventes a lesões cardíacas não apresentaram alterações ao eletrocardiograma e ecocardiograma. Ventrículo esquerdo e grau de lesão V da OIS-AAST estiveram relacionados a um maior número de alterações ao eletrocardiograma e ecocardiograma. Taquicardia sinusal e insuficiência mitral foram alterações encontradas em um de cada três doentes que sobreviveram a um ferimento cardíaco. / Objectives: To evaluate the evolution and the complications of the patients that survived cardiac wounds, attended at the Pronto-Socorro Municipal 28 de Agosto and Hospital Pronto-Socorro Dr. João Lúcio Pereira Machado, in Manaus, during the period of January 1998 until June 2006. Methods: A medical records evaluation was made among the patients attended at the two emergency hospitals in which a cardiac wound was found during a exploring thoracotomy. The survivors that returned to the ambulatory were evaluated prospectively through electrocardiogram and echocardiogram, so it was possible to analyze the morphology and the function of the heart. A protocol was filled out with a registry of patients data, such as: age, sex, trauma mechanism, intra-operative and post-operative complications, and other variables. Results: The total reference population in this study was 100 patients, in which 95% were male, the majority (69%) had ages until 30; 81% of the lesions were caused by stab wounds; 78% of the orifice of entry were located at the precordium; 41% of the lesions wounded the right ventricle and 38% wounded the left ventricle; In 48% of the cases a left antero-lateral thoracotomy was executed. The survival rate was 72%. The studied population was of 25 patients that returned to the ambulatory and were prospectively evaluated with electrocardiogram and echocardiogram. Among the 33 echocardiogram alterations (ECO), seven patients (28%) had mitral insufficiency, while nine (36%) didn\'t have any alterations. Among the 45 electrocardiogram alterations (ECG), eight patients (32%) had sinusal tachicardia, while six (24%) had no alterations. Time made no difference in the results of the ECO (p=0,5323) or of the ECG (p=0,6596). Of the 14 detected ECO complications, three (21,4%) were due to IV degree lesions in the right ventricle and eleven (78,7%) were due to V degree lesions (in the left ventricle) (p=0,048). From the 12 left ventricle lesions that complicated (ECG), 9 were V degree. From the 12 alterations detected at the ECG, three (25%) were due to IV degree lesions and nine (75%) were due to V degree lesions (p=0,226). Conclusions: Approximately one third of the cardiac wound survivors did not have alterations in the electrocardiogram and echocardiogram. Left ventricle and V degree lesions from the OIS-AAST were related to a larger number of alterations in the electrocardiogram and echocardiogram. Sinusal Tachicardia and mitral insuficiency were alterations found in one third of the patients that survived a cardiac wound.

Made available in DSpace on 2016-06-02T20:18:12Z (GMT). No. of bitstreams: 1 2946.pdf: 2432239 bytes, checksum: 38088e144c053efcf31c8e90a089b74f (MD5) Previous issue date: 2010-04-07 / Universidade Federal de Sao Carlos / Patients with chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) present significant exertional dyspnea. The peripheral muscle dysfunction appears to be the greatest impact on the inability to perform physical exercise. Additionally, there is respiratory muscle weakness caused by a limited supply of O2 and alteration of mechanical ventilation. In this context, in order to better understand the manifestations of these disorders and to establish management strategies, we have proposed the development of three studies. The first study was entitled Deep breathing heart rate variability is associated with respiratory muscle weakness in patients with chronic obstructive pulmonary disease . The purpose of the present investigation was to evaluate the influence of respiratory muscle strength on autonomic control of heart rate variability (HRV) in these patients. Ten COPD patients (69±9 years; forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) 59±12% and FEV1 41±11% predicted) and nine age-matched healthy male volunteers (64±5 years) participated in this study. The maximal inspiratory pressure was obtained in the sitting position. Then, electrocardiography signal was obtained in three conditions: 1) lying position for 15 min; 2) lying position during the respiratory sinusal arrhythmia maneuver (RSA-M) for 4 min; and 3) sitting position for 15 min. Data was analyzed by the time (RMSSD and SDNN indexes) and the frequency domains, in total power, low frequency (LF), high frequency (HF) absolute (ab) and normalized (nu) units and LF/HF ratio. Regarding the RSA-M indexes, the expiratory/inspiratory ratio (E/I) and the inspiratory/expiratory difference (&#916;IE) were calculated. The patients with COPD demonstrated significantly impaired cardiac autonomic modulation at rest and during RSA-M when compared with healthy subjects (ratio E/I: 1.1±0.06 vs. 1.2±0.1 e &#916;IE: 7.0±3.5 vs 12.7±4.2, respectively). Moreover, significant and positive correlations between maximal inspiratory pressure (MIP) and the inspiratory-expiratory difference (&#916;IE) (r = 0.60, p<0.01) were found. In conclusion, patients with COPD presented impaired sympathetic-vagal balance at rest and during RSA-M. In addition, cardiac autonomic control of heart rate was associated with inspiratory muscle weakness in chronic obstructive pulmonary disease. Based on this evidence, future research applications of respiratory muscle training may bring to light a potentially valuable target for rehabilitation. The second study was entitled to Deep breathing heart rate variability xviii is able to reflect the respiratory muscle weakness in chronic heart failure . The purpose of the present investigation was to evaluate the influence of respiratory muscle strength on autonomic control in these patients. Ten CHF (62 ± 7 years left ventricle eject fraction of 40 ± 5% and NYHA class I-III) and nine matched-age healthy volunteers (64±5 years) participated in this study. Heart rate variability (HRV) was obtained at rest and during RSA-M by electrocardiograph (as previously described). CHF patients demonstrated impaired cardiac autonomic modulation at rest and during RSA-M when compared with healthy subjects (p<0.05). Moreover, significant and positive correlations between MIP and IE-differences (r: 0.79), E/I ratio (r: 0.83), RMSSD (r: 0.77), SDNN (r: 0.77), LFab (r: 0.77), HFab (r: 0.70) were found during RSA-M. At rest, significant correlations were also found. Patients with CHF presented impaired sympathetic-vagal balance at rest. In addition, cardiac autonomic control of heart rate was associated with inspiratory muscle weakness in CHF. Based on this evidence, recommendations for future research applications of respiratory muscle training can bring to light a potentially valuable target for rehabilitation. Finally, the third study: "Behavior of heart rate on determination of anaerobic threshold in healthy men: comparison with cardiopulmonary exercise testing and near-infrared spectroscopy" aimed to identify the anaerobic threshold (AT) obtained from the V-slope method , visual method on oxihemoglobin (O2Hb) and deoxihemoglobin (HHb) and compare the method with heteroscedastic (HS) applied to VCO2, HR and HHb data. Secondly, to assess the degree of agreement between the methods for determination of AT. Fourteen healthy men were subjected to incremental cardiopulmonary test (CPT) in the electromagnetic cycle-ergometer until physical exhaustion. At the same time they obtained the following biological signals: (i) ventilatory and metabolic variables - a breath to breath - measured by the Cardio2 System (Medical Graphics Corporation, St. Paul, MO, USAI), (ii) spectroscopy, quasiinfrared rays - NIRS (NIRO 300 - Hamamatsu Photonics, Japan), and (iii) heart rate through cardiofrequencymeter (Polar S810i). We observed temporal equivalence and similar values of power (W), absolute O2 consumption (mL/min) and relative O2 consumption (mL/kg/min) and HR (bpm) on determination of AT by the methods performed. In addition, by the Bland-Altman plot, HR (bpm) confirmed the good agreement between the methods with biases between -1.3 and 3.5. In conclusion: (i) all methods were sensitive in identifying the AT1, including the HS applied to FC, and (ii) the methods showed a good correlation in the identification of AT1. Thus the xix results support the FC, a methodology that is simple and economically feasible, seems to be a valid parameter in determining the AT of the individuals in our study. Therefore it remains to be clarified if these results can be replicated in patients with chronic cardiopulmonary disorders, contributing in safe, individualized and adequate prescribing physical exercise in rehabilitation programs. / Pacientes com insuficiência cardíaca crônica (ICC) e doença pulmonar obstrutiva crônica (DPOC) apresentam significativa dispnéia exercional. A disfunção muscular periférica parece ser a causa de maior impacto na incapacidade de realização de exercício físico. Adicionalmente, pode coexistir a fraqueza muscular respiratória provocada pela limitada oferta de O2 e a alteração da mecânica ventilatória. Neste contexto, com intenção de compreender melhor as manifestações dessas disfunções e estabelecer estratégias de manejo, foi proposto o desenvolvimento de três estudos. O primeiro intitulado por Deep breathing heart rate variability is associated with respiratory muscle weakness in patients with chronic obstructive pulmonary disease teve como objetivo, avaliar a influência da fraqueza muscular inspiratória sobre a o controle autonômico da frequência cardíaca (FC) de homens com DPOC. Foram estudados 10 pacientes (69±9 anos; FEV1/FVC 59±12% and FEV1 41±11% do predito) e 9 homens saudáveis (64±5 anos). Na posição sentada, foi medida a pressão inspiratória máxima (PIMax) dos voluntários. Na sequência, em repouso, o sinal eletrocardiográfico foi obtido em três situações: 1) 15 min na posição supina; 2) quatro min durante a manobra de acentuação da arritmia sinusal respiratória (MASR) na posição supina; e 3) 15 min na posição sentada. Os dados foram analisados no domínio do tempo (índices RMSSD e SDNN) e da freqüência, pela densidade espectral total (DET), bandas de baixa (BF) e alta freqüências (AF) - absolutas (ab) e normalizadas (un), e a razão BF/AF. Durante M-ASR foram calculadas a razão expiração/inspiração (E/I) e a diferença inspiração/expiração (&#916;IE). Os pacientes com DPOC apresentaram valores significativamente menores da variabilidade da frequência cardíaca (VFC) quando comparados ao grupo controle em repouso e durante a M-ASR (razão E/I: 1,1±0,06 vs. 1,2±0,1 e &#916;IE: 7,0±3,5 vs 12,7±4,2, respectivamente). Adicionalmente, foi observado correlação positiva entre PIMax e &#916;IE (r = 0.60, p<0.01). Em conclusão: (i) pacientes com DPOC apresentam prejuízos da modulação autonômica da FC em repouso e durante a M-ASR; e (ii) a fraqueza muscular inspiratória parece influenciar no desbalanço simpato-vagal desses pacientes. Em similaridade, no segundo estudo, intitulado com Deep breathing heart rate variability is able to reflect the respiratory muscle weakness in chronic heart failure o objetivo foi avaliar a influência da PIMax no controle autonômico da FC de pacientes com ICC. Foram estudados 10 pacientes com ICC xv (62±7 anos Fração de Ejeção do ventrículo esquerdo de 40 ± 5% e classificação IIII da NYHA). Seguindo a metodologia descrita no estudo anterior, os resultados mostraram que os pacientes com ICC também apresentaram menores valores da VFC em repouso e durante a M-ASR e correlações positivas e significativas entre PIMax e diferença expiração-inspiração (r: 0,79), razão expiração/inspiração (r: 0,83), RMSSD (r: 0,77), SDNN (r: 0,77), BF (r: 0,77), AF (r: 0,70). Em conclusão: (i) pacientes com ICC apresentam prejuízos da modulação autonômica da FC em repouso e durante a M-ASR; e (ii) a fraqueza muscular inspiratória parece influenciar no desbalanço simpato-vagal desses pacientes. Por fim, o terceiro estudo: Comportamento da frequência cardíaca na determinação do limiar de anaerobiose em homens saudáveis: análise comparativa com o teste cardiopulmonar e a espectroscopia por raios quasi-infravermelhos objetivou identificar do limiar de anaerobiose (LA) obtido pelo método padrão-ouro, método visual pelo comportamento da oxihemoglobina (O2Hb) e deoxihemoglobina (HHb) e comparar com o método heteroscedástico (HS) aplicado aos dados de VCO2, HHb e da FC. Secundariamente, avaliar o grau de concordância entre os métodos de determinação do limiar de LA. Quatorze homens saudáveis foram submetidos ao teste cardiopulmonar (TCP) incremental em cicloergômetro de frenagem eletromagnética até a exaustão física. Concomitantemente foram obtidos os seguintes sinais biológicos: (i) variáveis ventilatórias e metabólicas respiração a respiração - medida pelo sistema CardiO2 System (Medical Graphics Corporation, St. Paul, MO, USAi); (ii) espectroscopia por raios quasi-infravermelhos - NIRS (NIRO 300 Hamamatsu Photonics, Japan); e (iii) frequência cardíaca por meio do cardiofreqüencímetro (Polar S810i). Foram observadas equivalências temporais e das variáveis potência (W), consumo de O2 absoluto (mL/min) e relativo (mL/kg/min) e FC (bpm) na determinação do LA pelos métodos empregados. Em adição, pela análise de Bland-Altman, a FC (bpm) confirmou a boa concordância entre os médotos com viéses entre -1,3 e 3,5. Em conclusão: (i) todos os métodos mostraram-se sensíveis na identificação do LA1, inclusive o HS aplicado a FC; e (ii) os médotos apresentaram boa correlação na identificação do LA1. Assim os resultados suportam que a FC, uma metodologia mais simples e economicamente viável, parece ser um parâmetro válido na determinação do LA dos indivíduos do nosso estudo. Agora, basta saber se estes resultados podem ser replicados em pacientes com disfunções cardiorrespiratórias crônicas, contribuíndo na prescrição xvi segura, individualizada e adequada de exercício físico em programas de reabilitação.

Les contractions rythmiques résultent de l’activité stimulatrice du nœud sinusal dans le cœur et des cellules interstitielles de Cajal (CICs) dans les intestins. Nous avons découvert un nouveau syndrome résultant d’une combinaison de la maladie du nœud sinusal (MNS) et de la pseudo-obstruction intestinale chronique (POIC). Ce syndrome, que nous avons nommé Chronic Atrial and Intestinal Dysrhythmia (CAID), résulte d’une mutation récessive du gène SGO1 (K23E). Cependant, les rôles connus de SGO1 n'expliquent pas l'apparition postnatale du syndrome ni la pathologie spécifique, suggérant que des rôles non canoniques de SGO1 conduisent aux manifestations cliniques observées. Cette hypothèse est supportée par la comparaison de CAID avec les autres cohésinopathies qui présentent principalement des phénotypes développementaux sans ou avec des défauts légers du cycle cellulaire. Ce projet visait à une découverte non biaisée des mécanismes non canoniques expliquant le syndrome CAID en utilisant le dogme de la biologie moléculaire (ADN→ARNm→protéine) comme ligne directrice. Pour ce faire, nous avons effectué des criblages multi-omiques sur des fibroblastes de peau de patients CAID et de contrôles sains. Les résultats des criblages ont été validés par électrophysiologie, étude des voies de signalisation pertinentes, immunohistochimie, pyroséquençage des rétrotransposons LINE-1 et quantification des marques d’histones. Nos études multi-omiques ont confirmé des changements dans la régulation du cycle cellulaire, mais aussi dans la conduction cardiaque et la fonction des muscles lisses. Plus spécifiquement, plusieurs canaux potassiques étaient sous-régulés. L’électrophysiologie a confirmé une diminution du courant potassique rectifiant entrant (IK1). L'immunohistochimie des coupes intestinales de patients CAID a confirmé l’augmentation de l’expression de SGO1 et BUB1, un régulateur de la voie de signalisation TGF-β. De plus, la voie canonique de TGF-β est augmentée et est découplée de la voie non canonique. Au niveau épigénétique, une signature unique d’hyperméthylation et de fermeture de la chromatine a été observée. Ce qui est soutenu par l’augmentation de la méthylation de H3K9me3 et de H3K27me3. En conclusion, le syndrome CAID est associé à plusieurs changements ayant possiblement un effet cumulatif plutôt que d’une seule voie de signalisation dérégulée. Nos résultats désignent la perturbation du courant IK1, la dérégulation de la signalisation TGF-β, l’hyperméthylation de l’ADN et la compaction de la chromatine comme éléments conducteurs potentiels des manifestations cliniques observées. La voie TGF-β et les changements épigénétiques peuvent être ciblées par des médicaments existants, constituant ainsi des cibles thérapeutiques prometteuses pour le traitement du syndrome CAID. / Rhythmic contractions are driven by the pacemaker activity of the cardiac sinus node and the intestinal interstitial cells of Cajal (ICC). We have discovered a new syndrome resulting from a combination of sick sinus syndrome (SSS) and chronic intestinal pseudo-obstruction (CIPO). This syndrome, which we have named Chronic Atrial and Intestinal Dysrhythmia (CAID), results from a recessive mutation in the SGO1 gene (K23E). However, the known roles of SGO1 do not explain the postnatal onset of the syndrome nor the specific pathology, suggesting that non-canonical roles of SGO1 lead to the clinical manifestations observed. This hypothesis is supported by the comparison of CAID with other cohesinopathies which mainly exhibit developmental phenotypes without or with mild cell cycle defects. This project aimed towards an unbiased discovery of noncanonical mechanisms explaining CAID using the molecular biology dogma (DNA→mRNA→protein) as a guideline. We performed multi-omic screens on skin fibroblasts from CAID patients and healthy controls. Screening results were validated by electrophysiology, study of relevant signaling pathways, immunohistochemistry, LINE-1 retrotransposon pyrosequencing, and histone marks quantification. Our multiomics analyses confirmed changes in cell cycle regulation, but also in cardiac conduction and smooth muscle function. More specifically, several potassium channels were downregulated. Electrophysiology studies confirmed a decrease in the inward rectifier potassium current (IK1). Immunohistochemistry in CAID patient’s intestinal sections confirmed overexpression of SGO1 and BUB1, a regulator of TGF-β signaling pathway. Additionally, the canonical TGF-β signaling was increased and decoupled from noncanonical signaling. At the epigenetic level, CAID patient fibroblasts have a unique signature of hypermethylation and chromatin closure. This is supported by the increased methylation of H3K9me3 and H3K27me3. In conclusion, CAID syndrome is associated with several changes that, may have a cumulative effect rather than a single deregulated signaling pathway. Our results reveal the disturbance of the IK1 current, the deregulation of TGF-β signaling, DNA hypermethylation and chromatin accessibility changes as potential conductors of intestinal and cardiac manifestations of CAID syndrome. In particular, the TGF-β pathway and epigenetic changes, may be targeted by existing drugs, thus constituting promising therapeutic targets for the treatment of CAID syndrome.

Le noeud sinusal (NS) est le centre de l‟automatisme cardiaque. Grâce à son activité électrique spontanée, il dicte la fréquence cardiaque (FC) en réponse aux demandes physiologiques. A ce jour, le NS demeure un sujet de recherche important puisque les mécanismes moléculaires responsables de sa régulation sont encore méconnus. Par exemple, les processus menant à la bradycardie sinusale et à la maladie du sinus (MS) chez les personnes âgées sont mécompris et présentement l‟implantation d‟un stimulateur cardiaque demeure le seul traitement disponible. Ainsi, l‟objectif de cette thèse était de déterminer les changements moléculaires et cellulaires se produisant au niveau du NS en réponse à divers stimuli physiologiques et pathologiques afin d'établir leurs rôles potentiels dans la régulation de la FC et le développement de la MS. Dans les deux premiers chapitres, la grossesse est présentée comme modèle physiologique. En effet, la réponse adaptative aux demandes croissantes de la mère et du foetus engendre des changements physiologiques considérables au niveau du myocarde, dont une augmentation de la FC essentielle pour la perfusion adéquate des organes. Toutefois, cette augmentation peut aussi favoriser le développement d‟arythmies. Dans le troisième chapitre, l‟inflammation, un facteur présent lors du vieillissement et dans plusieurs pathologies où la MS se manifeste, a fait l‟objet d‟une étude dans le but de déterminer son rôle dans le développement de la MS. Les résultats obtenus dans cette thèse démontrent que la grossesse induit une hausse de la FC chez la souris gestante similaire à celle retrouvée chez la femme enceinte. Cette accélération était due à un remodelage électrique du NS. Plus spécifiquement, la fréquence des potentiels d‟action ainsi que la densité et l‟expression des courants pacemaker (If) et calcique de type L (ICaL) étaient augmentées. De plus, une accélération des transitoires calciques spontanés et de la vitesse de relâche calcique du réticulum sarcoplasmique a été observée. La régulation de l‟automaticité par un stimulus pathologique, l‟interleukine-1β, est abordée par la suite. L‟interleukine-1β, une cytokine ayant un rôle majeur comme médiateur inflammatoire, se retrouve en concentrations élevées dans plusieurs maladies associées avec la ii MS. Nos résultats démontrent que l‟interleukine-1β engendre une diminution de l‟automaticité associée à une réduction de If et ICaL dans les cardiomyocytes humains de type nodal dérivés de cellules souches induites pluripotentes (hiPSC-CM). En parallèle, le phénotype électrophysiologique et moléculaire des hiPSC-CM a été caractérisé démontrant leur homologie avec les cellules du NS humain adulte, les validant comme modèle in vitro de cellules nodales humaines. En conclusion, les études présentées dans cette thèse démontrent que le NS est plus qu‟un simple tissu régulé par l‟innervation autonome. En effet, son automaticité est dynamique et peut être influencée par des facteurs physiologiques ou pathologiques. Nos résultats contribuent ainsi à une meilleure compréhension des mécanismes sous-jacents à l‟automaticité. Ces avancées sont importantes non seulement pour la santé des femmes, mais aussi pour les individus souffrant de la MS. À terme, nous espérons que ces résultats contribueront au développement de stratégies thérapeutiques pour traiter des complications liées aux troubles d‟automaticité cardiaque. / The sinoatrial node (SAN) is the dominant cardiac pacemaker. With its spontaneous automaticity, it dictates rhythm and controls heart rate in response to varying physiological demands. Despite its modest size, the SAN is a very heterogeneous and complex structure that remains the topic of research efforts due, in part, to uncertainties in the mechanisms that regulate pacemaking in various conditions. For instance, the processes that lead to severe sinus bradycardia and SAN dysfunction (SND) in the elderly are unknown and to date, the implantation of electronic pacemaker remains the only SND treatment. Accordingly, the overall objective of this thesis was to explore and highlight the molecular and cellular changes that occur within the SAN in both physiological and pathological states, while determining how they contribute to regulation of heart rate and potentially SND. In the first two chapters, we present pregnancy as a physiological model considering it is a period during which substantial adaptive changes to the myocardium and increases in heart rate occur. Paradoxically, the rapid rate, which is essential for adequate organ perfusion of both mother and foetus, may also increase vulnerability to certain arrhythmias. In the third chapter, inflammation, a central process in pathology and common factor to several diseases and even ageing, was evaluated as potential underlying circumstance contributing to the development of sinus bradycardia and SND. Combinations of in vivo, ex vivo, biochemical, molecular and cellular approaches were used in order to generate an integrated understanding of the models we examined. Our data shows that in pregnant mice, an increase in heart rate similar to that of pregnant women occurs and was due to an electrical remodelling of the SAN. Specifically, an increase in action potential frequency of isolated individual SAN cells was observed. This was attributed to increased expression and density of pacemaker (If) and L-type Ca2+ currents (ICaL) along with a rapid spontaneous Ca2+ transient rate and faster intracellular sarcoplasmic reticulum Ca2+ release. We then demonstrate that the pro-inflammatory cytokine interleukin-1β which is a major inflammatory mediator that is upregulated in several diseases associated with SND, iv dramatically slows automaticity by reducing If and ICaL density in nodal-like cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CM). Importantly, in that study, hiPSC-CMs were also physiologically and molecularly characterized revealing their high resemblance to adult human SAN and a potential use as a novel in vitro model to study pacemaking in humans. In conclusion, the results of this thesis demonstrate that the SAN is not a simple, neurally controlled tissue, but a rather dynamic pacemaker that undergoes extensive intrinsic remodelling during states of health and disease. The results contribute to understanding physiological mechanisms of pacemaking and how they are altered by disease and may be relevant for both women‟s health and the individuals affected by SND. Ultimately, we hope these findings will be helpful in the development of therapeutic strategies to treat pacemaking-related complications.

Foram poucos os estudos realizados para avaliar a capacidade da cavidade dos seios frontais para a diferenciação sexual. No entanto, a predição do sexo dos indivíduos é o passo mais importante para o desenvolvimento de um perfil biológico confiável durante a análise de restos esqueléticos. O advento da tomografia computadorizada por feixe cônico trouxe uma série de vantagens à clínica odontológica, e a quantidade de pacientes que realizam exames tomográficos para fins de diagnóstico tem aumentado cada vez mais permitindo com que estes dados sejam úteis para propósitos de identificação forense. Neste estudo, o objetivo foi propor uma nova metodologia para avaliar a capacidade de imagens em 3D da cavidade sinusal frontal, provenientes de tomografia computadorizada por feixe cônico, em determinar dimorfismo sexual entre os indivíduos. A amostra da pesquisa foi composta por 130 exames (65 do sexo masculino e 65 do sexo feminino) que foram segmentados e reconstruídos tridimensionalmente. O volume 3D foi exportado em formato Tiff nas normas frontal, lateral e basal. E as seguintes variáveis foram mensuradas em um segundo programa: área, perímetro, retângulo delimitador, elipse delimitadora, circularidade, razão de aspecto, arredondamento do objeto, solidez e diâmetro de Feret. O estudo foi capaz de demonstrar a existência de dimorfismo sexual com uma acurácia do modelo final de regressão logística igual a 80,0%. A norma basal foi a que garantiu maior poder de explicação na equação final. A metodologia foi validada e os resultados mostraram alto grau de confiabilidade. / There were few studies to assess the ability of the cavity of the frontal sinuses for sexual differentiation. However, the prediction of the sex of the individuals is the most important step in the development of a reliable biological profile during analysis of skeletal remains. The advent of cone beam computed tomography brought a number of advantages to the dental clinic, and the number of patients undergoing CT scans for diagnostic purposes has increased increasingly allowing that these data are useful for forensic identification purposes. The study aimed to propose a new methodology to assess the 3D images capacity of the frontal sinus cavity, from computed tomography cone beam, to attribute sexual dimorphism between individuals. The survey sample consisted of 130 exams (65 male and 65 female) who were reconstructed three-dimensionally. The 3D volume was exported in Tiff format in the frontal, side and basal views. In addition, the following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity and Feret\'s diameter. The study was able to demonstrate the existence of sexual dimorphism with an accuracy of the final logistic regression model equal to 80.0%. The basal view assured greater explanatory power in the final equation. The methodology has been validated and the results showed a high degree of reliability.

Made available in DSpace on 2016-06-02T20:19:03Z (GMT). No. of bitstreams: 1 1052.pdf: 1426257 bytes, checksum: 302057355291e83990486aed5f396a65 (MD5) Previous issue date: 2004-12-22 / Universidade Federal de Minas Gerais / The purpose of the present study was to evaluate the effects of the aging and the regular physical activity on the autonomic control of heart rate (HR) at rest and during deep breath test (DBT) in healthy men. Nine young sedentary (mean = 22.67 ±2.45 years), sixteen young active (mean = 22.38 ±2.13 years), eight sedentary older (mean = 63.5 ±2.39 years) and eight older active (mean = 61 ±1.6 years) men were studied. Electrocardiogram was continuously recorded during 15 minutes (rest), 4 minutes (DBT, with breath rate at 5 to 6 cycles/minute) and 1 minute (recovery) in supine position. The HR (bpm) and the R-R intervals (RRi) (ms) were analyzed by time (RMSSD index) and frequency domain methods. The power spectral components were expressed as absolute (a) and normalized units (nu) at low (LF) and high (HF), and as the LF/HF. The HR and the RRi were analyzed by the respiratory sinus arrhythmia (RSA) indices: expiration/inspiration ratio (E/I) and inspiration-expiration difference (&#8710;IE). The HR was lower in the activity groups than to the matched-age sedentary groups. The older sedentary group had lower heart rate variability (HRV), E/I and &#8710;IE than young ones. The older active group showed higher RMSSD and HF component than matched-age sedentary group (45.04 and 28.78 ms, 58,167 and 12,218 ms2/Hz, P<0.05; respectively). No differences were found between young and older active groups for RMSSD (61.71 and 45.04 ms, respectively) and HRV (TP:130,816 and 125,710, LFa:33,295 and 32,611, HFa:84,346 and 58,167, ms2/Hz, respectively) and DBT indices (E/I: 1.40 and 1.35, &#8710;IE: 23 and 18, respectively). The results show that aging associates with inactivity reduces the HRV. However, the regular physical activity increases the HRV, independent of age, suggesting attenuation the effects of the aging in the autonomic control of the heart rate. / O presente estudo teve como objetivo avaliar os efeitos da idade e da atividade física regular sobre o controle autonômico da freqüência cardíaca (FC) durante o repouso e durante a manobra para acentuar a arritmia sinusal respiratória (MASR) em homens saudáveis. Participaram do presente estudo, 9 jovens sedentários (média= 22,67 ±2,45 anos), 16 jovens ativos (média= 22,38 ±2,13 anos), 8 idosos sedentários (média= 63,5 ±2,39 anos) e 8 idosos ativos (média= 61 ±1,6 anos). O traçado eletrocardiográfico foi registrado durante 15 minutos (repouso com respiração espontânea), 4 minutos (MASR, com freqüência respiratória mantida entre 5 a 6 ciclos/minuto) e 1 minuto de recuperação. A freqüência cardíaca (FC), em bpm, e os intervalos RR (iR-R), em ms, foram analisados pelo domínio do tempo (índice RMSSD) e pelo domínio da freqüência. Os componentes da potência espectral foram expressos em valores absolutos (a) e em unidades normalizadas (un) para a densidade total de potência (DTP), as bandas de baixa freqüência (BF), alta freqüência (AF) e razão BF/AF. A FC obtida durante a manobra MASR foi analisada a partir dos índices: razão expiração/inspiração dos iR-R (E/I) e de sua variação durante a inspiração-expiração (&#8710;IE). Os grupos ativos apresentaram valores inferiores de FC de repouso em comparação aos controles sedentários de mesma idade. O grupo idoso sedentário apresentou menor variabilidade da variabilidade da freqüência cardíaca (VFC), E/I e &#8710;IE que o grupo jovem sedentário. O grupo idoso ativo mostrou valores superiores de RMSSD e da banda de HF em relação ao grupo sedentário idoso (45,04 e 28,78 ms, 58.167 e 12.218 ms2/Hz, p<0,05; respectivamente). Diferenças estatísticas não foram encontradas entre o grupo jovem ativo e idoso ativo para o RMSSD (61,71 e 45,04 ms, respectivamente) e para a VFC (DTP: 130.816 e 125.710, LFa: 33.295 e 32.611, HFa: 84.346 e 58.167, ms2/Hz, respectivamente) e para os índices da ASR (E/I: 1,40 e 1,35, &#8710;IE: 23 e 18, respectivamente). Para os grupos sedentários foi observado correlação negativa entre os índices DTP, AFa, E/I e &#8710;IE e a idade (p<0,05), sendo que o mesmo não pode ser observado nos grupos ativos. Os resultados sugerem que o envelhecimento associado ao sedentarismo provoca reduções na VFC, representadas pela diminuição da atividade vagal sobre o coração, determinada tanto pela análise no domínio da freqüência como pelos índices da arritmia sinusal respiratória. Entretanto, a atividade física regular aumenta a VFC, independentemente da idade, e atenua as alterações, decorrentes do processo de envelhecimento, no controle autonômico da freqüência cardíaca.

Foram poucos os estudos realizados para avaliar a capacidade da cavidade dos seios frontais para a diferenciação sexual. No entanto, a predição do sexo dos indivíduos é o passo mais importante para o desenvolvimento de um perfil biológico confiável durante a análise de restos esqueléticos. O advento da tomografia computadorizada por feixe cônico trouxe uma série de vantagens à clínica odontológica, e a quantidade de pacientes que realizam exames tomográficos para fins de diagnóstico tem aumentado cada vez mais permitindo com que estes dados sejam úteis para propósitos de identificação forense. Neste estudo, o objetivo foi propor uma nova metodologia para avaliar a capacidade de imagens em 3D da cavidade sinusal frontal, provenientes de tomografia computadorizada por feixe cônico, em determinar dimorfismo sexual entre os indivíduos. A amostra da pesquisa foi composta por 130 exames (65 do sexo masculino e 65 do sexo feminino) que foram segmentados e reconstruídos tridimensionalmente. O volume 3D foi exportado em formato Tiff nas normas frontal, lateral e basal. E as seguintes variáveis foram mensuradas em um segundo programa: área, perímetro, retângulo delimitador, elipse delimitadora, circularidade, razão de aspecto, arredondamento do objeto, solidez e diâmetro de Feret. O estudo foi capaz de demonstrar a existência de dimorfismo sexual com uma acurácia do modelo final de regressão logística igual a 80,0%. A norma basal foi a que garantiu maior poder de explicação na equação final. A metodologia foi validada e os resultados mostraram alto grau de confiabilidade. / There were few studies to assess the ability of the cavity of the frontal sinuses for sexual differentiation. However, the prediction of the sex of the individuals is the most important step in the development of a reliable biological profile during analysis of skeletal remains. The advent of cone beam computed tomography brought a number of advantages to the dental clinic, and the number of patients undergoing CT scans for diagnostic purposes has increased increasingly allowing that these data are useful for forensic identification purposes. The study aimed to propose a new methodology to assess the 3D images capacity of the frontal sinus cavity, from computed tomography cone beam, to attribute sexual dimorphism between individuals. The survey sample consisted of 130 exams (65 male and 65 female) who were reconstructed three-dimensionally. The 3D volume was exported in Tiff format in the frontal, side and basal views. In addition, the following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity and Feret\'s diameter. The study was able to demonstrate the existence of sexual dimorphism with an accuracy of the final logistic regression model equal to 80.0%. The basal view assured greater explanatory power in the final equation. The methodology has been validated and the results showed a high degree of reliability.

Les méthanogènes sont des Archaea anaérobies stricts, connus pour être les seuls êtres vivants capables de produire du méthane comme sous-produit de leur métabolisme. Notre revue de littérature a montré qu’outre les espèces environnementales, l’ordre des Methanomassiliicoccales ne comptait à ce jour qu’une seule espèce Methanomassiliicoccus luminyensis isolée et cultivée dans notre laboratoire. Aucours de notre thèse, nous avons développé une nouvelle méthode permettant la culture et l’isolement des méthanogènes en absence de source externe de dihydrogène (H2) d’une part et d’autre part une méthode de génotypage Multispacer Sequence Typing (MST) basée sur le séquençage d’espaces intergéniques pour typer Methanobrevibacter smithii et M. oralis. Par la suite, nous avons mis en évidence la présence de méthanogènes en situation pathologique chez l’homme. Nous avons détecté et isolé pour la première fois au sein de flores anaérobies, M. oralis à partir d’échantillons d’abcès cérébraux, et de sinusite d’une part, et d’autre part M. smithii à partir d’un échantillon de patient souffrant d’abcès para-vertébral. Enfin, dans la cinquième partie de notre thèse, nous avons testé in vitro la sensibilité de cinq méthanogènes associés aux flores humaines à la lovastatine qui est une pro-drogue utilisée pour abaisser la concentration de cholestérol chez l’homme dans le cadre de certaines pathologies. Les cinq méthanogènes se sont avérées sensibles à une concentration minimale inhibitrice de 1µg/mL, après activation par hydrolyse de la lovastatine par des bactéries anaérobies du microbiote digestif, via une l’inhibition de la croissance et de la production du méthane. / Methanogens are strict anaerobic Archaea, known to the only being able to producing methane gas as a byproduct. Methanogens which are not detected in clinical microbiology laboratories were present in oral, digestive, vaginal and cutaneous microbiota of human. Only five species on the thirteen known in human have been cultivated before the beginning of our thesis. In our thesis, we initially reviewed the state of knowledge about methanogens in human microbiota, particularly the new order Methanomassiliicoccales of methylotrophic methanogens, the as member of human microbiota. In the second part of this work, we performing new method for methanogens culture and isolation without any dihydrogen atmosphere, by co-cultured in tubes methanogens with Bacteroides thetaiotaomicron, which produces hydrogen. We also developed Multispacer Sequence Typing (MST), a genotyping method based on intergenic spacers sequencing, to genotype M. oralis and Methanobrevibacter. Smithii. We demonstrated that methanogens could be part of polymicrobial infection in the case of brain and sinusal abscesses, and also in skeletal muscle abscess, by isolating for the first time M. oralis and M. smithii in these pathologies, using culture-based and molecular-based approaches, and suggested that methanogens could be considered as human opportunistic or emerging pathogens. Finally, we tested the in vitro susceptibility of lovastatin which is a prodrug used as a powerful serum cholesterol-lowering drug in some human diseases and showed that it’s inhibits growth and methane production in human-associated methanogens without affecting intestinal bacteria.

Introduction : La gestion d'une urgence vitale requiert la réalisation de gestes techniques et une communication entre les soignants en condition de stress. La simulation permet cet enseignement en sécurité.Objectif : Analyser l'association entre stress et performance et l'effet de la simulation répétée. Méthodes : Deux groupes expérimental et contrôle de 6 équipes pluri-professionnelles de SAMU (n = 48), avaient respectivement 9 (1/6 semaines) et 3 (1/6 mois) simulations, avec 3 scénarios communs : initial, intermédiaire à 6 mois, final à 1 an. Le stress a été évalué par la fréquence cardiaque et sa variabilité, le cortisol salivaire et des paramètres psychologiques (échelles de : stress aigu STAI et SOM ; stress post-traumatique IES-R et PCLS) ; la performance technique par les scores de pose de voie intra-osseuse (VIO), de performance globale (TAPAS) ; la performance non-technique par les scores BAT du leader, CTS de l'équipe.Résultats : Le stress augmentait durant la simulation (p < 0,02) et baissait lors du débriefing (p < 0,01) quelle que soit la fréquence de répétition, sans stress post-traumatique. Les performances étaient corrélées entre elles (p < 0,001) avec un lien étroit entre les scores BAT (leader) et CTS (équipe) (R² = 0,93). Stress et performance n'étaient pas corrélés. La performance était supérieure dans le groupe expérimental dès le scénario intermédiaire pour les scores techniques (TAPAS : p = 0,02, VIO : p = 0,03) et pour tous les scores lors du scénario final (TAPAS et IO : p = 0,01, CTS : p = 0,03, BAT : p = 0,02).Conclusion : La répétition de séances de simulation toutes les 6 semaines apportait un bénéfice majeur. La performance d'équipe était liée à celle du leader. / Introduction: The management of a life-threatening event by caregivers requires technical and non-technical skills under stress conditions. Simulation-based education allows this training in a safe environment. Objective: To analyze the association between stress and performance and the effect of repeated simulation.Methods: Two experimental and control groups of 6 MDTs of EMS (n=48) had respectively 9 (1session/6 weeks) and 3 (1session/6 months) simulations with 3 common sessions: initial, intermediate after 6 months, and final session after 1 year. Stress was assessed by heart rate and variability, salivary cortisol and psychological parameters (acute stress: STAI and SOM, and PTSD: IES-R and PCLS). The technical performance was evaluated by Intra-Osseous Access Performance Assessment Scale (IO), overall performance (TAPAS); non-technical performance by BAT score for leader and CTS score for teamwork.Results: Stress increased during simulation (p<0.02) and decreased during debriefing (p<0.01) regardless of the frequency of repetition. There was no PTSD. The performances were correlated between each other (p<0.001) with a strong link between the non-technical performance of leader and team (R²=0.93). Stress and performance were not correlated. The performance was higher in the experimental group during the intermediate scenario for technical scores (TAPAS: p=0.02, IO: p=0.03) and for all scores during the final scenario (TAPAS and IO: p=0.01 CTS: p=0.03, BAT : p=0.02).Conclusion: The benefit was greater when performing simulations every six weeks in terms of technical and non-technical performance. The team performance was linked to the leader performance.

Los receptores &#946;-adrenérgicos (&#946;AR) y de serotonina (5-HT4) median sus efectos en tejidos cardiacos a través de la ruta receptor-Gs-AC-AMPc. Las fosfodiesterasas (PDE) son una amplia familia de enzimas cuya función es la degradación del AMPc. Se desconocía que isoenzimas de PDEs son responsables de la hidrólisis de AMPc en las diferentes regiones cardiacas. El objetivo de esta tesis doctoral es investigar que isoenzimas de PDEs tienen actividad en el miocardio humano, porcino y de roedores. Se han realizado estudios cronotrópicos, inotrópicos, lusitrópicos, bioquímicos y electrofisiológicos. Los principales resultados son: Las PDEs se comportan de manera distinta en las diferentes regiones cardiacas y compartimentos celulares; y La frecuencia basal de nódulo sinusal está controlada por PDEs pero en ninguna especie estudiada las PDEs controlan la taquicardia causada por los &#946;ARs y los receptores 5-HT4. La extrapolación de la función de las PDEs al humano debe h acerse con cautela. / Myocardial &#946;-adrenoceptors (&#946;AR) and serotonin receptors (5-HT4) mediate their signals through the receptor-Gs-AC-cAMP pathway. Phosphodiesterases (PDEs) are a large enzyme family that degrade cAMP. It was unknown which PDE isoenzymes are responsible for the hydrolysis of the cAMP in different cardiac regions. The aim of this doctoral thesis is to investigate which isoenzymes have a role in human, porcine and rodent myocardium. We performed chronotropic, inotropic, lusitropic, biochemical and electrophysiological studies. The key results are: PDEs have different roles in different cardiac regions and cellular compartments; and the basal beating rate of the sinoatrial node is controlled by PDE3 and/or PDE4, but these PDEs do not limit the tachycardia mediated through the stimulation of &#946;1AR, &#946;2AR and 5-HT4. Given the diverse roles of PDE3 and PDE4 and their dependence on species, extrapolation to humans should be done cautiously because these animal models usually do not reflect the human myocardium.