Orientador: Miguel Arcanjo Areas / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T14:53:44Z (GMT). No. of bitstreams: 1 Ramos_LuizAlbertoFerreira_M.pdf: 1275435 bytes, checksum: f06c87a51cddb170d7e8f43b748231ce (MD5) Previous issue date: 2010 / Resumo: A Hipertensão Arterial Pulmonar (HAP) é uma patologia caracterizada pelo aumento da resistência dos vasos pulmonares, aumento na pressão Arterial pulmonar e hipertrofia do ventrículo direito, prejudicando as trocas gasosas alveolares e a função cardíaca. Por outro lado, a melatonina (N-Acetil-5- metoxitriptamina), o principal hormônio produzido pela glândula pineal, pode reduzir o tônus do músculo liso vascular promovendo redução da resistência periférica e, consequentemente, diminuição da pressão arterial em ratos hipertensos. O objetivo deste trabalho foi avaliar o efeito da melatonina sobre parâmetros cardiovasculares de ratos portadores de HAP induzida por monocrotalina. Ratos Wistar adultos pesando com 250g foram distribuídos em quatro grupos experimentais (n=5): CO (controle); CML (controle melatonina); MT (monocrotalina); MTML (monocrotalina+melatonina). A HAP foi induzida pela administração de dose única de monocrotalina (60 mg/kg i.p.) no primeiro dia de experimento. Melatonina (15 mg/kg i.p.) foi administrada diariamente, durante os 28 dias do período experimental. Os animais foram anestesiados (ketamina 100 mg/kg + xilazina 7 mg/kg de peso corpóreo i.m.) para a obtenção de parâmetros eletrocardiográficos e avaliação da pressão arterial e, posteriormente foram submetidos à eutanásia por aprofundamento anestésico, para o estudo da reatividade vascular e para análise histológica do coração e pulmões. Os resultados mostraram que melatonina reduziu significativamente a resposta contrátil da artéria pulmonar em relação aos ratos controles e portadores de HAP para resposta mínima da reatividade vascular à noradrenalina. A análise histológica mostrou que a melatonina aumentou significativamente a área do lúmen das artérias pré-acinares pulmonares e a área alveolar do grupo MTML, em relação ao grupo MT, o qual apresentou valores significativamente reduzidos, em relação ao grupo CO. Além disso, a melatonina proporcionou nos animais tratados com monocrotalina menor desvio do eixo elétrico para a direita em consequência, provavelmente, do menor grau de hipertrofia ventricular direita o que acarretou em redução do intervalo QT e, consequentemente, na prevenção do risco de morte súbita decorrente das alterações cardíacas desencadeadas pela hipertensão arterial pulmonar. Melatonina, também, preveniu a redução da pressão arterial média nos animais cuja oxigenação tecidual encontrava-se, provavelmente, prejudicada pelas alterações pulmonares e cardíacas induzidas pela monocrotalina. Concluindo, melatonina atenuou os efeitos deletérios da monocrotalina sobre parâmetros cardiovasculares e pulmonares neste modelo de hipertensão arterial pulmonar / Abstract: Pulmonary arterial hypertension (PAH) is a disease characterized by increased pulmonary vascular resistance, increased pulmonary arterial pressure and right ventricular hypertrophy and impairs alveolar gas exchange and cardiac function. Moreover, melatonin (N-acetyl-5-metoxytryptamine), the main hormone produced by the pineal gland can reduce the tone of vascular smooth muscle was a reduction in peripheral resistance and thus lowering blood pressure in hypertensive rats. The objective of this study was to evaluate the effect of melatonin on cardiovascular parameters of rats with monocrotaline-induced PAH. Male Wistar rats weighing 250g were divided into four experimental groups (n = 5): CO (control), CML (control melatonin), MT (monocrotaline), MTML (monocrotaline + melatonin). PAH was induced by administration of single dose of monocrotaline (60 mg / kg ip) on the first day of the experiment. Melatonin (15 mg / kg ip) was administered daily for 28 days trial period. The animals were anesthetized (Ketamine 100 mg / kg + xylazine 7 mg / kg body weight im) to obtain electrocardiographic parameters and blood pressure evaluation and later euthanized by deep anesthesia, to study the vascular reactivity and for histological analysis of the heart and lungs. The results showed that melatonin significantly reduced the contractile response of pulmonary artery and control rats with PAH for maximum response of vascular reactivity to norepinephrine. Histological analysis showed that melatonin significantly increased the lumen area of the pre-acinar pulmonary alveolar area and the group's HTML, for the TM group, which had significantly reduced compared to the CO group. Moreover, melatonin delivered in animals treated with monocrotaline minor electrical axis deviation to the right as a result, probably the lowest degree of right ventricular hypertrophy which resulted in a reduction of the QT interval and thus to prevent the risk of sudden death due of cardiac abnormalities triggered by pulmonary arterial hypertension. Melatonin also prevented the reduction in mean arterial pressure in animals in which tissue oxygenation was, probably affected by changes in pulmonary and cardiac changes induced by monocrotaline. In conclusion, melatonin attenuated the deleterious effects of monocrotaline on cardiovascular parameters in this model of pulmonary arterial hypertension / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Objetivamos neste estudo avaliar de maneira quantitativa as alterações do parênquima e da vasculatura pulmonar em exames de angiotomografia computadorizada (angioTC) de pacientes com hipertensão pulmonar (HP), utilizando programa de análise totalmente automática. Foram analisados retrospectivamente os prontuários físicos e eletrônicos e os exames de angioTC de 45 pacientes com HP, em comparação com um grupo controle. Os pacientes com HP também foram divididos de acordo com a classificação de Nice, sendo representados principalmente pelos grupos 1 (hipertensão arterial pulmonar, incluindo a idiopática) e grupo 4 (hipertensão pulmonar secundária ao tromboembolismo crônico). A análise automática mostrou que os pacientes com HP apresentaram valores menores do percentil 10 (p10) da densidade dos pulmões e valores maiores de volume vascular do lobo superior direito (LSD) e de volume vascular relativo entre lobos superiores e inferiores. Neste estudo não encontramos diferenças da análise quantitativa por TC entre os grupos de pacientes com HP. Inferimos que a diferença nos valores de p10 indique a presença das áreas hipoatenuantes de oligoemia nos pacientes com HP, enquanto as diferenças nos volumes vasculares indiquem a redistribuição da trama vascular pulmonar. A análise quantitativa da vasculatura pulmonar em imagens de angioTC pode representar uma ferramenta diagnóstica objetiva na avaliação da HP. / In this study, we aimed to quantitatively analyze the lung parenchyma and pulmonary vasculature in computadorized tomography angiography (angioCT) from patients with pulmonary hypertension (PH), using a complete automated software. We retrospectively analyzed 45 patients\'s exams and clinical records, comparing with a control group. Patients were also divided in groups, according to Nice classification, represented mainly by group 1 (pulmonary arterial hypertension, including idiopathic) and 4 (chronic thromboembolic pulmonary hypertension). In patients with PH, the automated analysis found lower values of the 10th percentile (p10) of pulmonary density and higher values of vessel volumes in the upper right lobe (RUL) and higher relative vessel volumes between the uppers and lowers lobes. In this study, we didn\'t find any difference between the groups of patients with PH in the quantitative analysis of angioCT. We infer that the p10 differences indicate presence of hypoattenuating areas of olygoemia in patients with PH and that the difference in pulmonary vessel volumes indicates pulmonary vasculature redistribution. The analysis of pulmonary vessels in angioCT images can represent an objective diagnostic tool in PH evaluation.

A hipertensão pulmonar (HP) é uma doença caracterizada por elevação da pressão da artéria pulmonar e um aumento da resistência vascular pulmonar levando à disfunção do ventrículo direito, sendo complicação importante de doenças como a doença pulmonar obstrutiva crônica (DPOC), doença pulmonar intersticial (DPI), colagenoses e vasculites. A tomografia computadoriza de alta resolução (TCAR) é um dos principais métodos de diagnóstico e acompanhamento destas doenças. Neste estudo objetivamos a analise quantitativa dos exames de TCAR do tórax em pacientes com doenças parenquimatosas difusas e hipertensão pulmonar diagnosticada por cateterismo direito. Foram analisados retrospectivamente os prontuários eletrônicos e os exames de TCAR de 29 pacientes com HP, em comparação com um grupo controle. Foram excluídos os casos de hipertensão arterial pulmonar primária e tromboembolismo crônico, cuja investigação é feita prioritariamente com exame de angiotomografia. A análise quantitativa foi realizada utilizando programa completamente automático e algumas medidas manuais também foram realizadas. O pacientes com HP, quando comparados ao controle, apresentaram redução do volume pulmonar, aumento da atenuação média do parênquima, aumento na medida do volume vascular pulmonar, aumento da densidade vascular pulmonar e na relação do volume vascular nos lobos superiores em relação aos lobos inferiores. O programa automático foi capaz de identificar as alterações da vasculatura, mesmo em se tratando de exames não contrastados e em meio a alterações arquiteturais do parênquima pulmonar. Estes achados provavelmente representam a redistribuição da trama vascular pulmonar, relacionada ao aumento da resistência vascular pulmonar. A análise quantitativa automática, realizada em exames de TCAR já utilizados na rotina clínica, pode representar nova ferramenta não invasiva capaz de identificar sinais de HP em pacientes com fator de risco, como DPOC, DPI, colagenoses, em que a HP representa complicação importante e de diagnóstico muitas vezes difícil / Pulmonary hypertension (PH) is a disease characterized by elevation in the mean pressure of the pulmonary artery and an increase in the pulmonary vascular resistance leading to right heart dysfunction, being an important complication of multiple diseases such as chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD), collagen diseases and vasculitis. The high resolution computed tomography (HRCT) is one of the main diagnostic methods and is also important in the follow up of these patients. In this study we aim the quantitative analysis of the thoracic HRCT exams in patients with diffuse parenchymal lung disease and pulmonary hypertension diagnosed by right heart catheterism. We analised retrospectively the clinical records and HRCT exams of 29 patients with PH, comparing to a control group. Were excluded from the study patients with primary pulmonary arterial hypertension (PAH) and chronic thromboembolism pulmonary hypertension (CTEPH), which investigations usually include pulmonary angiotomography. The quantitative analysis was made utilizing a completely automatic software and some manual measures were also noted. Patients with PH, when comparing to control group, presented significant pulmonary volume reduction, elevated mean parenchymal attenuation, elevated measures of the pulmonary vascular volume, increase in the pulmonary vascular density and also an elevation in the relation between vascular volume in the upper pulmonary lobes and the lower lobes. The automatic software was able to identify the vascular alterations, even in non contrast enhanced exams and amidst architectural distortions in the lung parenchyma. These findings probably represent the redistribution of the pulmonary vascular bed, related to the pulmonary vascular resistance increase. .The quantitative automatic analysis, made in HRCT exams, used in clinical practice, can represent a new non invasive tool, able to identify PH signs in risc patients, such as COPD, ILD and collagen diseases, in which PH represents an important complication with, many times, difficult diagnosis.

O tromboembolismo pulmonar causado por obstrução de ramos arteriais pulmonares por trombos originados de outras partes do corpo apresenta elevada incidência. Em 5% dos casos ocorre a cronificação do processo e manutenção ou agravamento da hipertensão pulmonar Duas hipóteses explicam a cronificação nos casos de embolia pulmonar: 1. manutenção do fator oclusivo como fundamental para o desenvolvimento da resposta vascular pulmonar caracterizada por hipertrofia da camada média; 2. hipertensão pulmonar secundária a uma arteriopatia inicial, nos pacientes que evoluíram de maneira desfavorável. Este estudo tem por objetivo avaliar sob critérios histopatológicos qualitativos e quantitativos o comportamento do leito arterial pulmonar distal (pré e intra-acinar), comparativamente em pulmões de pacientes sem tromboembolismo prévio e de pacientes portadores de tromboembolismo agudo e crônico. Para tanto, estudou-se a resposta vascular através de estudo histológico de 31 casos de embolia (aguda e crônica), comparando-os com 24 pacientes do grupo controle (Infarto agudo do miocárdio) (análise de autópsias). As lâminas de tecido pulmonar foram preparadas e coradas em hematoxilina-eosina e Miller. A análise realizada foi dividida em qualitativa (vasoconstrição e proliferação intimal concêntrica) e quantitativa (hipertrofia da camada média). Foram observadas alterações histopatológicas do leito arterial pulmonar distal nos pacientes portadores de quadro tromboembólico agudo e crônico, em relação aos pacientes sem tromboembolismo prévio. Estas alterações, entre os grupos agudo e crônico, foram: diferentes quanto aos critérios qualitativos, caracterizadas por maior vasoconstrição nos quadros tromboembólicos agudos e maior proliferação intimal concêntrica nos crônicos; semelhantes quanto aos critérios quantitativos, caracterizadas por hipertrofia da camada média. A isquemia decorrente da obstrução parece exercer um importante papel nestas alterações, o que, entretanto, necessita de comprovação futura / The pulmonary embolism, caused by pulmonary artery branches obstruction from thrombus originated on other parts of the body, has a high incidence. However, just 5% of the cases develop the cronification and pulmonary hypertension. Two hypotheses can explain the cronification of tromboembolic pulmonary events: 1. maintenance of occlusive factor with pulmonary vascular response characterized by medial hypertrophy; 2. pulmonary hypertensive response as an initial arteriopathy in patients with bad evolution. This study aims to evaluate histologic aspects of pulmonary arterial bed (quantitative and qualitative), and to compare the results from embolic cases with non embolic cases. The study evaluated 55 patients (31 with pulmonary embolic disease and 24 in the control group myocardium infarction). From the selected cases, the blades with pulmonary tissue were colored by two techniques (haematoxilin-eosin and Miller). The analysis encompassed qualitative (vasoconstriction and intimal proliferation) and quantitative (mensuration of medial thickness) observations. It has been observed histologic changes between the two groups with pulmonary embolic disease (chronic or acute), and the control group. The changes between the embolic groups were: 1. higher vasoconstriction in the acute group, 2. more intimal proliferation in the chronic group, 3. no difference in the quantitative response (medial thickness). The ischemic response to obstruction can perform an important role in these changes, but further studies are necessary. There was a similar response in chronic and acute cases

Orientador: Miguel Arcanjo Areas / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-25T17:57:02Z (GMT). No. of bitstreams: 1 Ramos_LuizAlbertoFerreira_D.pdf: 4150802 bytes, checksum: 044f485e191cccd920c14229719c65ce (MD5) Previous issue date: 2014 / Resumo: A Hipertensão Arterial Pulmonar (HAP) é uma patologia caracterizada pelo aumento da resistência dos vasos pulmonares, aumento da pressão arterial pulmonar e hipertrofia do ventrículo direito do coração, prejudicando as trocas gasosas alveolares e a função cardíaca. Por outro lado, a melatonina (N-Acetil-5-metoxitriptamina), hormônio produzido principalmente pela glândula pineal, diminui o tônus do músculo liso vascular promovendo redução da resistência periférica, assim como efeito cardioprotetor devido a sua ação antioxidante. O objetivo deste trabalho foi avaliar o provável efeito cardioprotetor da melatonina em ratos portadores de HAP. A HAP foi induzida pela administração de dose única de monocrotalina (60mg/kg ip) no primeiro dia do período experimental. Após os primeiros 15 dias, tempo necessário à instalação da HAP, melatonina (10mg/kg ip) foi administrada diariamente, durante 13 dias. Os animais foram distribuídos em quatro grupos experimentais (n=5): CO (controle); MEL (controle melatonina); MCT (monocrotalina); MCT+MEL (monocrotalina+melatonina). Ao final do período experimental de 28 dias, os animais foram anestesiados (ketamina 100mg/kg + xilazina 7mg/kg de peso i.m) para a determinação de parâmetros eletrocardiográficos e da Variabilidade da Frequência Cardíaca (VFC). Posteriormente, foram submetidos à eutanásia, por aprofundamento anestésico, obtendo-se o coração para a determinação de biomarcadores cardíacos, enzimas antioxidantes do tecido cardíaco, parâmetros hemodinâmicos e análise histológica das artérias coronárias do ventrículo direito. Os resultados do ECG mostraram que a melatonina, nos animais portadores de HAP, minimizou as alterações na frequência cardíaca, na despolarização atrial e ventricular, assim como nos parâmetros indicativos de risco de morte súbita. Além disso, melatonina reduziu a hipertrofia ventricular direita, preveniu o aumento da espessura da camada média das artérias coronárias e aumentou a atividade das enzimas antioxidantes do coração dos animais portadores de HAP, o que pode ter contribuído para a ausência dos eventos do ECG indicativos de isquemia miocárdica, como observados no grupo MCT. Quanto aos aspectos hemodinâmicos, melatonina preveniu a redução da pressão arterial média, da pressão sistólica e do índice de relaxamento ventricular melhorando, assim, a função sistólica e diastólica dos animais estudados. Em conclusão, melatonina exerceu efeito protetor contra as alterações cardíacas decorrentes da hipertensão arterial pulmonar induzida pela monocrotalina / Abstract: Pulmonary Arterial Hypertension (PAH) is a disease characterized by increased pulmonary vascular resistance, higher pulmonary artery pressure and right ventricular hypertrophy of the heart and impairs alveolar gas exchange and cardiac function. Furthermore, melatonin (N-acetyl-5-methoxytryptamine) is a hormone produced primarily by the pineal gland, which decreases the tone of vascular smooth muscle promoting a reduction in peripheral resistance, as well as cardioprotective effect due to its antioxidant action. The objective of this study was to evaluate the probable cardioprotective effect of melatonin in rats with PAH. PAH was induced by administration of a single dose of monocrotaline (60mg/kg ip) on the 1st day of the experimental period. After 15 days, the time needed to install the HAP melatonin (10mg/kg i.p.) was administered daily further 13 days. The animals were divided into four experimental groups (n = 5): CO (control); MEL (control melatonin); MCT (monocrotaline); MCT + MEL (monocrotaline + melatonin). At the end of the experimental period (28 days), the animals were anesthetized (100mg/kg ketamine + xylazine 7mg/kg weight i.m.) to determine the ECG parameters and Heart Rate Variability (HRV). The animals were subsequently euthanized by deep anesthesia, give the hearts were resected to determine the cardiac biomarkers, antioxidant enzymes in cardiac tissue, hemodynamic parameters and the histological analysis of the coronary arteries were from the right ventricle. The ECG results showed that melatonin, in PAH rats, reduced changes in heart rate, atrial and ventricular depolarization, as well as in parameters indicative of risk of sudden death. Moreover, melatonin reduced the right ventricular hypertrophy, prevented the increase in medial thickness of the coronary arteries, increasing the activity of antioxidant enzymes in the heart of PAH animals, which may have contributed to the absence of ECG events indicative of myocardial ischemia, as observed in the MCT group. Regarding hemodynamic aspects melatonin prevented the reduction in mean arterial pressure, systolic pressure and left ventricular relaxation rate, thereby improving systolic and diastolic function in the animals studied. In conclusion, melatonin exerted a protective effect against heart changes resulted from monocrotaline-induced pulmonary hypertension / Doutorado / Fisiologia / Doutor em Biologia Funcional e Molecular

Sildenafil citrate (SC) is a phosphodiesterase-5 inhibitor that is used to treat pulmonary hypertension (PH) in paediatric patients. The purpose of these studies was to develop a formulation and manufacture an orodispersible tablet (ODT) that can be easily administered to neonates and children with PH. The advantages of ODT dosage forms include ease of administration, rapid dissolution of the API, SC. Furthermore the dosage form can be taken without water which is beneficial to patients without immediate access to potable fluids. A simple, rapid, accurate, precise and selective reversed-phase HPLC method was developed and validated in accordance with International Conference on Harmonization (ICH) guidelines and was successfully used for the analysis of SC as raw material and in SC containing pharmaceutical dosage forms. Preformulation studies were performed on SC, alone and in combination with potential excipients that could be used to make tablets. Investigations into potential interactions between SC and the excipients were performed using Differential Scanning Calorimetry (DSC) and Infrared Spectroscopy (IR). DSC results revealed that SC was compatible with all potential excipients except mannitol and magnesium stearate. However these interactions were not observed with IR and therefore it was concluded that the interactions were induced by the high temperatures that DSC operates at. Particle size and shape was also established by use of Scanning Electron Microscopy (SEM) and flow properties were monitored by calculating Carr’s Index (CI) and the Hausner Ratio (HR). Direct compression was used as the method of manufacture for SC tablets as this approach is simple and the most economic production approach. The powder blends were assessed for bulk and tapped density and the CI and HR were used to determine the flowability of the blends. The quality attributes of the resultant tablets that were monitored included uniformity of weight, friability, crushing strength, tensile strength, disintegration, wetting and in vitro dispersion times. Design of Experiments is an efficient statistical approach that has become a popular tool used in the pharmaceutical industry to optimize formulation compositions, as it allows for the investigation of several input factors at the same time whilst not using the tedious and traditional “ modification of one variable at a time” approach. A Central composite experimental design was chosen as the most appropriate means to optimize the formulation as it produces more accurate results as opposed to other experimental designs approaches as input factors are investigated at five different levels. Through the use of mathematical modelling, optimum concentrations of disintegrant(s) and an appropriate blending time were established. Analysis of the data from the experimental design and mathematical modelling studies reveal that no changes in disintegrant concentration or blending time altered the disintegration time of the formulation to any significant extent. This result is most likely due to the fact that the critical disintegrant concentration has been reached and increasing the disintegrant concentration further has no effect on disintegration time. It was also established that a change in the concentration of CMS and CRP altered the wetting time of the tablet significantly. Finally it was noted that there was a linear relationship between blending time and the uniformity of content of the tablets produced in these studies. The optimized product was a white tablet with a diameter of 7.31 mm with a thickness of 2.80mm.The dosage form had no visible cracks or evidence of picking or sticking. The tablet exhibits suitable friability and tensile strength while exhibiting a disintegration time of only 8s. Therefore an orodispersible tablet containing SC intended for paediatric use has been successfully developed, manufactured and optimized through the use of preformulation studies, appropriate quality control monitoring and mathematical modelling. These formulations require further optimization in respect of addition of flavours and or additional sweetening agents.

INTRODUÇÃO: As Hemoglobinopatias podem ser divididas em Talassemias e Doença Falciforme (DF), mas do ponto de vista clínico, ambas apresentam um quadro de anemia hemolítica crônica, o que acarreta uma série de complicações, entre estas a Hipertensão Pulmonar (HP). Estima-se que cerca de 20-40% da população com DF/talassemia apresente HP, sendo que este diagnóstico está associado a uma elevada morbi-mortalidade. Poucos estudos avaliaram esta prevalência em crianças. O Objetivo deste estudo foi avaliar a prevalência desta complicação na população pediátrica, e associá-la com características clínicas e laboratoriais. MÉTODOS: Estudo de Corte Transversal, com avaliação de 45 pacientes com diagnóstico de DF ou Talassemia maior/ intermédia entre 3-18 anos, atendidos de forma consecutiva no ambulatório de Hemoglobinopatias do HCPA. Os pacientes foram submetidos a um ecocardiograma para estimativa da pressão sistólica da artéria pulmonar, sendo que foi considerado como tendo risco de HP os pacientes com velocidade de regurgitação tricúspide (VRT) ≥ 2,5m/s. Foram obtidos dados clínicos e laboratoriais para avaliação dos parâmetros hemolíticos, função hepática e renal por levantamento de prontuário e comparados os grupos. RESULTADOS: 15% (6/40) dos pacientes apresentaram VRT ≥ 2,5m/s, sugestivo de HP, sendo que destes pacientes todos tinham diagnóstico de Anemia Falciforme (AF). Considerando apenas esta população, a prevalência de HP aumenta para 20% (6/30). A população com VRT ≥ 2,5m/s apresentou média de idade mais elevada, Hb mais baixa, RDW mais alargado, reticulócitos e LDH mais elevado que o grupo com VRT < 2,5m/s. A principal intercorrência clínica nesta população foi a ocorrência de priapismo (p< 0,05). CONCLUSÕES: Os pacientes com Hemoglobinopatias estão em risco aumentado para desenvolvimento de HP desde a infância, principalmente aqueles com AF. Estes pacientes apresentam os parâmetros laboratoriais sugestivos de hemólise alterados, assim como outros sintomas associados ao quadro hemolítico como o priapismo quando comparados com pacientes com VRT normal. Desta forma sugere-se a realização de triagem com ecocardiograma nesta população de forma precoce. / INTRODUCTION: The Hemoglobinopathies can be divided in Thalassemias and Sickle Cell Disease (SCD), but clinically both present with chronic hemolytic anemia, which leads to various complications, one of them being Pulmonary Hypertension (PH). About 20-40% of patients with SCD have PH, and this diagnosis is associated with a high risk of mortality. The objective of this study was to estimate the prevalence of this complication in the pediatric population, and associate clinical and laboratory characteristics. METHODS: A cross sectional descriptive study, with the evaluation of 45 patients with diagnosis of SCD or thalassemia major/intermedia between 3-18 years, which received treatment at the Hemoglobinopathies ambulatory at HCPA. The patients were submitted to an echocardiogram to estimate the pulmonary artery systolic pressure, being considered to have PH patients with a tricuspid regurgitate jet velocity (TRV) ≥ 2.5m/s. Clinical and laboratory data were obtained to evaluate hemolytic parameters, renal and liver function and compared between groups. RESULTS: 15% (6/40) of patients had a TRV ≥ 2.5m/s, suggestive of PH, of which all had Sickle Cell Anemia (SCA). Considering this group of patients alone the prevalence would be of 20% (6/30). Patients with TRV ≥ 2.5m/s had a higher median age, lower hemoglobin count, higher RDW, reticulocyte and DHL then patients with a TRV < 2.5m/s. The major clinical feature was the occurrence of priapism (p<0,05). CONCLUSIONS: Patients with diagnosis of hemoglobinopathies are at higher risk of developing PH since early childhood, especially those with SCA. These patients showed a higher level of hemolytic parameters, as well as symptoms associated with hemolysis, like priapism, when compared with patients with a normal TRV. Therefore, it would be indicated to submit these patients to an echocardiogram routinely in their early years.

A qualidade de vida relacionada à saúde tem aparecido, com frequência, entre as metas dos estudos clínicos destinados ao desenvolvimento de novos tratamentos para a hipertensão arterial pulmonar (HAP). Embora os novos tratamentos melhorem o desempenho ao exercício na fase inicial de 12 - 16 semanas, não se sabe se existe associação entre tolerância ao exercício e qualidade de vida (QV), sobretudo em médio e longo prazo. Os objetivos do estudo foram: a) verificar, em pacientes com HAP, a existência ou não de correlação entre a QV e desempenho físico; b) verificar como as possíveis associações entre QV e desempenho ao exercício se comporta ao longo de um ano de observação sob tratamento medicamentoso específico; c) verificar se a aplicação de um protocolo de orientação de enfermagem, especificamente planejado para pacientes com HAP, poderia exercer impacto sobre a QV e o desempenho físico. Foram incluídos 34 pacientes no estudo, adolescentes ou adultos com o diagnóstico de HAP idiopática, hereditária ou associada a cardiopatias congênitas. Para o comprimento do terceiro objetivo, os pacientes foram organizados em pares, seguindo-se randomização para o tipo de seguimento a que seriam submetidos: apenas orientação médica ou orientação médica seguida de consulta de enfermagem. O acompanhamento constou de cinco visitas, a saber, no início, e aos três, seis, nove e 12 meses. Nas visitas, foram avaliados o desempenho físico, através da classe funcional e do teste de caminhada de seis minutos, e a QV mediante aplicação do questionário SF-36. A idade variou entre 14 e 58 anos (mediana de 35,5 anos). Houve dez pacientes com o diagnostico de hipertensão arterial pulmonar idiopática, dois na forma hereditária e 22 indivíduos com a forma associada a cardiopatias congênitas. Com relação à classe funcional, 25 pacientes estavam em classe II e nove em classe III. A distância caminhada inicialmente foi 177 a 564 metros (mediana 399 metros). A saturação periférica de oxigênio em repouso esteve entre 63 e 98% (mediana 94,5%), e ao final do exercício, foi de 38 a 98% (mediana de 84%). Com relação aos escores de QV iniciais (valores de zero a 100, representando respectivamente pior e melhor estado de saúde), somente duas das oito categorias analisadas através do questionário SF-36 mostraram valores medianos abaixo de 50, ambas relacionadas à saúde física. Analisando-se os 31 pacientes que completaram 12 meses de seguimento, observou-se que não houve modificação com significância estatística na classe funcional, distância caminhada aos seis minutos, na saturação periférica de oxigênio e nos escores do questionário SF-36, componentes físico e mental da QV. Analisando-se todas as 40 possíveis correlações entre a distância caminhada e as oito diferentes categorias do questionário, observou-se 12 associações significantes ao longo do seguimento (p< 0,05, relacionado ao coeficiente rS de Spearman). O limite em termos de distância caminhada abaixo do qual os pacientes passariam a expressar maior insatisfação em relação à sua QV (escores 25) situou-se entre 235 e 285 metros percorridos, com especificidade superior a 0,90. Entretanto, a baixa sensibilidade (máxima 0,42) sugeriu que diversos pacientes expressariam tal descontentamento mesmo com desempenho físico acima do intervalo mencionado. Com relação ao tipo de consulta, ainda que subjetivamente se tenha observado maior esclarecimento quanto à doença e seu tratamento em alguns pacientes acompanhados com a consulta suplementar de enfermagem, não houve diferenças estatísticas quanto à classe funcional, distância percorrida aos seis minutos ou escores de QV. Os dados observados permitiram concluir que pacientes portadores de HAP, nas subcategorias diagnósticas analisadas, uma vez colocados em tratamento específico, se mantêm estáveis, em médio prazo, sem deterioração significante de seu desempenho físico e QV. Apesar do tratamento em curso, o maior grau de insatisfação está relacionado à percepção da saúde física. Evolutivamente, a associação entre desempenho físico e QV existe em apenas 30% das oportunidades avaliadas. Pacientes caminhando, menos de 235 metros no teste de caminhada, quase certamente expressarão insatisfação marcante em relação à sua QV. Finalmente, com respeito à consulta de enfermagem, embora subjetivamente se tenha tido impressão de seu real papel, não houve impacto demonstrado objetivamente com significância estatística. Assim, desempenho físico e QV se mostram como aspectos complementar a serem avaliados em pacientes com HAP / Health-related quality of life (HRQOL) has been explored as an additional end point in clinical studies for development of new therapies in pulmonary arterial hypertension (PAH). Although treatments have been shown to improve the exercise capacity in 12-16 weeks, little is known of how patients do over the medium and long term on these therapies, in terms of HTQOL. The objectives of the present study were: 1- to observe how PAH patients do on specific therapies over 12 months of follow-up in terms of the exercise capacity and HRQOL; 2- to test for possible associations between the exercise capacity and HRQOL, and determine if such associations persist over the medium term (12 months); 3- to examine if a PAH-specific nursing approach (following conventional visits to the doctor) has a positive impact on patients exercise capacity and quality of life. Thirty-four patients were enrolled, with PAH associated with congenital heart disease (N=22) or idiopathic/hereditary PAH (N=12). Patients were seen at baseline, and three, six, nine and twelve months thereafter. The exercise capacity was assessed by performing the six-minute walk test, and the quality of life using the SF-36 questionnaire. The functional class was recorded according to the World Health Organization classification. The age range was 14 to 58 years (median 35.5 years). Patients were in functional class II (N=25) or III (N=9), and baseline six-minute walked distance was 177 to 564 meters (median 399 meters). Peripheral oxygen saturation was 63% to 98% (median 94.5%) at rest, and 38% to 98% (median 84%) at the end of the exercise. At baseline, in two of the eight domains of the SF-36 questionnaire (physical functioning and physical role), median score were lower than 50 (0-100 scale, 100 indicating best health). In 31 patients who completed the follow-up, there were no statistically significant changes in the functional class, six-minute walked distance, peripheral oxygen saturation and SF-36 scores. All these variables remained stable in the whole patient group. Of 40 possible associations between the exercise capacity and aspects of HRQOL analyzed over 12 months, only 12 were statistically significant (p<0.05, Spearmans coefficient of correlation). Using regression models, it was observed that patients walking less than 235-280 meters during the six-minute test had a severe depression in HRQOL (SF-26 scores 25). Although the specificity was adequate (> 0.90) the low sensitivity of prediction ( 0.42) indicated that many patients would be unsatisfied with their quality of life even above this range. Nursing assistance did not add a significant benefit in terms of the sixminute walked distance or the SF-36 scores in PAH patients on treatment with specific therapies. On the basis of the present data, it is possible to conclude that patients on specific PAH therapies tend to remain stable over 12 months of observation in terms of the exercise capacity and HRQOL. It is noticeable that most patients in the study had PAH associated with congenital heart disease (no patients with systemic sclerosis included). Dissatisfaction in terms of HRQOL is mainly related to the perception of physical health. Over the medium term, associations between HRQOL and the exercise capacity are present in only 30% of instances, suggesting that these are different perspectives of patients health. Anyway, patients walking less than 235 meters in six-minutes are very likely to express severely depressed HRQOL. Finally, further studies possibly using qualitative research methodology are warranted for a better understanding of the role of nursing assistance in this disorder

L’insuffisance cardiaque droite est la première cause de mortalité des patients atteints d’hypertension pulmonaire (HP). Au début de la maladie, le ventricule droit (VD) opère un remodelage permettant une adaptation à l’augmentation des résistances vasculaires pulmonaires. Au cours de cette adaptation, les caractéristiques morphologiques, fonctionnelles et myocardiques se modifient. L’analyse de ces modifications peut s’appliquer en clinique au niveau du dépistage, de l’évaluation pronostique et du suivi des patients atteints d’HP. Néanmoins, la physiopathologie du passage d’un état compensé à un état décompensé reste à élucider de même que l’identification de nouvelles cibles thérapeutiques ou l’élaboration de méthodes non-invasives d’évaluation du VD restent à développer. L’objectif de cette thèse était d’évaluer un moyen de dépistage de l’HP en échographie cardiaque et d’étudier la physiopathologie de la défaillance ventriculaire droite sur un cœur droit remodelé. Un large rappel des notions d’anatomie, d’embryologie et de physiologie nécessaires à la compréhension des paramètres d’évaluation du VD a été réalisé, puis des études originales publiées et en cours ont été présentées.Une première étude s’est intéressée au dépistage échocardiographique d’une HP chez des patients avec une pathologie pulmonaire avancée. Nous avons montré que la dilatation de l’oreillette droite, du VD et certains paramètres fonctionnels étaient liés à une HP. Lorsque la fuite tricuspidienne était quantifiable (chez 52% des patients), l’évaluation d’autres paramètres du VD n‘améliorait pas le dépistage d’une HP. La présence de paramètres du VD anormaux chez les patients dont la fuite tricuspidienne n’était pas quantifiable n’améliorait pas le dépistage ; 20% des patients sans HP présentaient une dilatation du VD. Une validation extrinsèque chez l’animal avec une obstruction vasculaire pulmonaire modérée et progressive confirmait que la dilatation du VD était un des paramètres les plus précoces quantifiable lors du développement d’une HP. Le développement d’indices non-invasifs du VD plus spécifique d’une l’HP est nécessaire.Une seconde étude, nous avons caractérisé les modifications du VD au cours d’une insuffisance cardiaque droite aigue survenant dans le cadre d’une HP dans une nouveau modèle animal. Le VD était évalué avec des paramètres de courbes pression-volume, d’échocardiographie, de cathétérisme cardiaque droit et par des biomarqueurs circulants. L’analyse anatomopathologique et protéique du VD, environ 3 heures après la restauration hémodynamique, retrouvait des lésions d’ischémie sous-endocardiques et sous-épicardiques et des stigmates d’activation d’autophagie. Nous avons retrouvé des lésions sous-endocardiques du VD similaires chez 5 patients avec une HP ayant bénéficié d’une transplantation cardiopulmonaire dans un contexte de défaillance hémodynamique. Des données préliminaires suggèrent que ces lésions sont associées aux défaillances rénales et hépatiques et à une altération de la survie après transplantation cardiopulmonaire.En conclusion, certains signes de remodelage du VD peuvent être présents chez des patients avec des pathologies pulmonaires avancés en l’absence d’HP, ce qui limite leur intérêt pour le diagnostic non-invasif d’une HP. A l’autre extrémité du spectre de sévérité d’une HP, nous avons modélisé pour la première fois une insuffisance cardiaque droite aigue dans un modèle animal d’HP. Nous avons démontré pour la première fois que des lésions ischémiques pouvaient se développer dans le VD en quelques heures malgré l’induction d’une restauration hémodynamique avec de la dobutamine. Ces données apportent un rationnel fort pour l’évaluation des lésions tissulaires du VD à l’aide de biomarqueurs circulant en pratique clinique dont les applications restent à établir. / Right heart failure is the leading cause of mortality in patients with pulmonary hypertension (PH). At early stage of PH the right ventricle (RV) remodels to adapt to the increased pulmonary vascular resistances. This adaptation is characterized by morphological, functional and myocardial changes. The evaluation of these changes may be applied for screening, prognosis evaluation and follow-up of patients with PH. However, the pathophysiology of the transition from adaptive to maladaptive phenotypes remains unclear; and identification of RV therapeutic targets and noninvasive methods for its evaluation remains to developed. The aim of this thesis was to evaluate non-invasive screening of PH with echocardiography and to study the pathophysiology of acute right heart failure in the setting of chronic PH by performing precise phenotyping of a new large animal model. A wide review of anatomic, embryologic and physiologic concepts was performed to help for the understanding of parameters of RV evaluation; then published and ongoing original studies were presented.In a first study, we investigated PH screening with echocardiography in patients with advanced lung disease. In this study, we showed that enlargement of the RV and of the right atrium, as well as function parameters of the RV were associated with PH. When the tricuspid regurgitation was available (52% of cases), RV morphology and function parameters did not improve PH diagnosis. Abnormal RV morphology and function without available tricuspid regurgitation provided moderate detection value; whereas 20% of patients without PH presented enlargement of the RV. In a large animal model with progressive increase in pulmonary artery mechanical obstruction, enlargement of the RV was the earliest RV parameter associated with PH development. This study highlights the need for more specific RV indices of PH.In a second study we investigated right ventricular changes in a new large animal model of acute right heart failure occurring on chronic PH; a situation associated with around 40% mid term mortality or transplantation. We characterized right ventricular changes during acute volume and pressure overload and after hemodynamic restauration in a large animal model of chronic thromboembolic PH. The RV was evaluated with parameters derived from pressure-volume loops, echocardiography, right heart catheterism and with circulating biomarkers. Pathological and proteins content analyzes of the RV around 3 hours after hemodynamic restauration showed acute subendocardial and subepicardial focal ischemic lesions as well as signs of autophagy activation. We found similar ischemic lesions in RV of 5 patients who underwent a heart-lung transplantation for PH in the setting of hemodynamic compromise. Preliminary data suggest that these lesions are associated with end-organ injury and poor overall survival after heart-lung transplantation in patients with PH.In conclusion, abnormal echocardiographic right heart metrics may be observed in patients with advanced lung disease without PH limiting their use for PH screening in this population. This highlight the need for more specific right heart metrics associated with PH. At the other extreme of the spectrum of PH severity, we described for the first time a large animal model of acute right heart failure in chronic PH. We reproduced and described the main morphological and functional features observed in acute right heart failure on PH and we showed for the first time that acute right ventricular ischemic lesions may develop within few hours despite hemodynamic restauration with dobutamine. These data provide a strong rational to develop specific biomarkers to evaluate tissue lesions of the right ventricle and determine their clinical implications.

L’hypertension pulmonaire (HTP) est la principale pathologie de la circulation pulmonaire. Elle secaractérise par une augmentation maintenue de la pression dans les artères intrapulmonaires (AIP) (> à 25mmHg au repos). Cette pression exerce des forces d’étirement au niveau des cellules musculaires lisses desartères intrapulmonaires (CML d’AIP). Au niveau des CML, des canaux mécanosensibles appelés des SAC(« stretch-activated channels ») permettent de transformer un stimulus mécanique d’étirement en uneréponse biologique de contraction : c’est le tonus myogénique. Le Ca2+ est un second messager cellulairequi peut être aussi bien mobilisé depuis le milieu extracellulaire que depuis les réserves calciquesintracellulaires. Une augmentation de sa concentration cytoplasmique induit la contraction des CML. Grâceà des techniques de patch-clamp, de microspectrofluorimétrie, d’immunomarquages et à une approchepharmacologique, nous avons mis en évidence les voies de signalisations calciques qui sont mises en placeà la suite d’un étirement des CML d’AIP. Les expériences ont été réalisées à la fois chez des rats normaux etsur deux modèles de rats présentant une HTP (rats hypoxique chroniques et rats monocrotalines). Lesrésultats montrent que chez les rats normaux un étirement induit un influx de Ca2+ par les SAC. Cet influxcalcique est amplifié par (1) une hyperpolarisation de la membrane plasmique via l’activation de canauxBKCa, (2) une sortie de Ca2+ par les récepteurs à la ryanodine de type 1 (RyR1) du réticulum sarcoplasmique(RS) sous-membranaire. Afin de rétablir l’homéostasie calcique, les mitochondries tamponnent le Ca2+cytosolique. Chez les rats souffrant d’HTP, l’influx de Ca2+ par les SAC et l’amplification calcique par les RyRsont plus importants. Cette amplification est due à une réorganisation des réserves calciquesintracellulaires, notamment chez les rats monocrotalines. De plus, une association fonctionnelle entre lesréserves calciques du RS et les cavéoles conduit à des réponses calciques plus importantes après unétirement chez les rats HTP. Enfin, nous avons mis en évidence la présence de canaux mécanosensiblesPiezo1 dans les AIP de rats. En conclusion, l’organisation spatiale des partenaires calciques au sein des CMLd’AIP est importante pour la signalisation cellulaire et joue un rôle majeur dans l’HTP. / Pulmonary hypertension (PH) is the main disease of the pulmonary circulation. This pathology ischaracterized by an increase of the intrapulmonary arterial (PA) pressure at rest (> 25 mmHg). This pressureexerts stretch forces on pulmonary arterial smooth muscle cells (PASMC). Stretch-activated channels (SAC)are present in PASMC and are able to transform a mechanical stimulus of stretch into a biological responseof contraction, a phenomenon called myogenic tone. Ca2+ is a second messenger that can be mobilizedfrom both the extracellular medium and intracellular Ca2+ stores. An increase of the intracellular Ca2+concentration ([Ca2+]i) leads to PASMC contraction. Using patch-clamp, microspectrofluorimetry,immunostainings and a pharmacological approach, we highlight Ca2+ signaling pathways induced by stretchin PASMC. Experiments were performed in normal rats and in two models of PH (chronically hypoxic ratsand monocrotaline rats). We showed that in normal rats a stretch induces a Ca2+ influx through SAC whichis amplified by (1) a plasma membrane hyperpolarization by BKCa channels and (2) a Ca2+ amplification bysubplasmalemnal ryanodine receptor 1 (RyR) of the sarcoplasmic reticulum (SR). Besides, mitochondria areinvolved in buffering cytoplasmic Ca2+. In PH rats, the Ca2+ influx by SAC and the Ca2+ release by RyR areenhanced due to a reorganization of intracellular Ca2+ stores. Furthermore, a functional associationbetween SR and caveolae conduce to a much greater amplification of the stretch-induced Ca2+ increase inPH rats. Finally, we showed that the mechanosensitive channel Piezo1 is expressed in PA. To conclude, thespatial organization of Ca2+ stores in PASMC is important for cell signaling and plays a casual role in PH.