Proefschrift--Utrecht. / "Stellingen": [2] p. inserted. Summary in Dutch. Bibliography: p. 115-120.

Thesis (Ph.D.)--University of California, San Francisco, 2004. / Includes bibliographical references. Also available online.

Thesis (M.S.)--Florida State University, 2006. / Advisor: B. Bryant Chase, Florida State University, College of Arts and Sciences, Dept. of Biological Sciences. Title and description from dissertation home page (viewed June 7, 2006). Document formatted into pages; contains viii, 57 pages. Includes bibliographical references.

The treatment of asthma still relies on primary therapy with bronchodilators; in particular β adrenergic receptor (bAR) agonists with a diverse range of short acting and long acting βARs available. An increase in the number of cardiovascular events with the use of bronchodilators have recently been reported including hypertrophy, heart failure, myocardial ischaemia and infarction. Several subtypes of βAR receptors exist including the β1 Adrenergic Receptor (β1AR) and β2 Adrenergic Receptor (β2AR), both located in the heart. The effects of selective β2AR agonists were investigated in the Langendorff model of myocardial ischaemia reperfusion injury, isolated perfused rat hearts underwent 35 minutes of ischaemia and 120 minutes of reperfusion. The selective β2AR long acting β agonists Formoterol and Salmeterol had no significant effect on infarct to risk ratio or time taken to depolarisation and hypercontracture in isolated cardiomyocytes. The non-selective β1AR agonist Isoproterenol has been show to induce myocardial ischaemia and infarction in rat hearts previously, here we demonstrated Isoproterenol (0.5μM) significantly decreased time taken to depolarisation and hypercontracture in isolated cardiomyocytes. The short acting β2AR agonist Salbutamol (0.01μ-1μM) significantly increased infarct to risk ratio in the Langendorff in addition to significantly decreasing time to hypercontracture in cardiomyocytes in the oxidative stress model highlighting a potential role of the mitochondrial permeability transition pore (mPTP). Activation of phosphorylated Akt and phosphorylated Erk1/2 via the PI3K/Akt signalling pathway and p44/p42 MAPK pathway were investigated by western blot analysis. Salbutamol significantly elevated expression of p-Akt in rat hearts exposed to reperfusion for 20 and 120 minutes whilst reducing expression of p-Erk. Recorded elevated cleaved caspase 3 expression in Salbutamol treated hearts can be associated as a marker of increased in cardiomyocyte cell death. The β1AR antagonist CGP 20712 was administered in the presence of Salbutamol with minimal reduction in infarct size in rat hearts recorded and no significant change in time taken to hypercontracture in isolated cardiomyocytes suggesting that Salbutamol mediated toxicity is via β2AR activation. Confirmation of this was verified with the β2AR antagonist ICI 118, 551. Significant decrease in infarct size was recorded in addition to a significant increase in time to hypercontracture in the oxidative stress model. Further to this, caspase 3 expression was significantly reduced in addition with p-Akt expression. With a potential role of the mitochondria and the mPTP contributing to Salbutamol induced myocardial injury, the Cyclophilin D inhibitor Cyclosporin A was administered in hearts and cardiomyocytes in the presence of Salbutamol. Infarct size was significantly reduced whilst time taken to hypercontracture significantly increased, suggesting that CsA treatment inhibits Salbutamol mediated injury via Cyclophilin D inhibition of the mPTP. To conclude, our results demonstrated that Salbutamol caused cardiotoxicity at tissue, cellular and protein level in conditions of ischaemia reperfusion injury. Further to this, inhibition of Cyclophilin D by CsA, or the use of the β2AR antagonist ICI 118, 551 inhibits Salbutamol induced toxicity.

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The management of the asymptomatic patients with severe aortic stenosis (AS) is challenging; clinicians have to balance the risks of early surgery against the risk that irreversible myocardial damage may occur with a conservative management strategy. It has become increasingly apparent that prognosis in asymptomatic AS depends not only on the degree of valvular stenosis, but also on the myocardial response to pressure overload and understanding the mechanisms of myocardial decompensation may help to guide management in the future. The degree of myocardial fibrosis, microvascular dysfunction, hypertrophy and left ventricular (LV) geometry may all play important roles. However, current guidelines for management of asymptomatic AS limit assessment of the myocardium to the measurement of ejection fraction with echocardiography. More advanced techniques may provide greater information that could be clinically useful. This thesis seeks to further our understanding of the mechanisms of the myocardial response to AS, using Cardiac Magnetic Resonance (CMR) in patients with moderate and severe AS. Myocardial perfusion in AS is examined in chapter 3. The results show that CMR first pass perfusion can be carried out safely and is well tolerated by AS patients. Microvascular dysfunction in these patients was associated with age, exercise time and markers of diastolic dysfunction. Myocardial strain is examined in chapter 4, utilizing a new software tool to look at strain throughout the left ventricle, and also to explore the relationship between strain and myocardial fibrosis. The results show that there are significant variations in circumferential strain measurements, depending on slice position in the LV, and also that there was no relationship found between strain and the degree of LV fibrosis. In chapter 5, the potential of CMR T1 mapping to identify fibrosis is examined using a new shortened non-contrast sequence (ShMOLLI - Shortened Modified Look-Locker Inversion) developed in our unit. CMR T1 values were validated against histological quantification of myocardial fibrosis in a large group of moderate and asymptomatic AS. A good correlation was found between ShMOLLI derived T1 values, with T1 values increasing with the severity of AS. The clinical value of measuring myocardial perfusion and LV global strain is examined in chapter 6 by linking these to prognosis. Measurement of circumferential strain could predict prognosis in asymptomatic AS, but myocardial perfusion showed poor ability to predict events. In conclusion, this thesis offers further insights into the changes that occur in the myocardium of patients with asymptomatic moderate and severe AS, using established and new CMR techniques. The clinical value of measuring these CMR parameters to aid risk stratification is shown, and the future potential for monitoring new therapies in these patients is discussed in the final chapter.

Orientador: Carlos Alberto Vicentini / Banca: Luis Alberto Domingo Francia Farje / Banca: Maria Terezinha Siqueira Bombonato / Resumo: O Arapaima gigas é uma espécie nativa da bacia amazônica que apresenta transição no modo de respiração. Em estágios iniciais do desenvolvimento, esta espécie possui respiração exclusivamente aquática, alterando para respiração aérea com aproximadamente 9 dias após eclosão dos ovos. Essa transição está associada a modificações morfológicas nas brânquias que se tornam cada vez menos eficientes para realizar trocas gasosas, tornando esta espécie progressivamente mais dependente do oxigênio atmosférico. Entretanto, não se sabe se esta característica pode afetar a morfologia cardíaca. Em relação ao coração de teleósteos, o ventrículo é uma câmara que exibe grande variabilidade morfológica entre as espécies e pode apresentar características específicas em espécies adaptadas a condições ambientais extremas. Diante do exposto, o objetivo do presente estudo foi descrever a morfologia cardíaca em A. gigas com ênfase na mioarquitetura ventricular e a distribuição de vasos coronários durante etapas de seu desenvolvimento relacionadas a dependência da respiração aérea. Assim, foram utilizados espécimes distribuídos em três grupos de acordo com o peso dos animais e dependência da respiração aérea (grupo 1 - baixa dependência; grupo 2 - transição; grupo 3 - alta dependência). Os corações foram coletados e submetidos a análise anatômica, ultraestrutural e histológica. O ventrículo de A. gigas apresentou alterações anatômicas entre os grupos, exibindo inicialmente aspecto sacular com miocárdi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Arapaima gigas is a native species of the Amazon basin that presents a transition in the breathing mode. In early stages of development, this species has exclusively water breathing, changing to air breathing with approximately 9 days after egg hatching. This transition is associated with morphological changes in the gills that become less and less efficient to perform gas exchange, making this species progressively more dependent on atmospheric oxygen. However, it is not known whether this feature can affect cardiac morphology. In relation to the teleosts heart, the ventricle is a chamber that exhibits great morphological variability among the species and may present specific characteristics in species adapted to extreme environmental conditions. Thus, the objective of the present study was to describe the cardiac morphology in A. gigas with emphasis on ventricular myoarchitecture and distribution of coronary vessels in stages of its development related to the dependence of air breathing. To perform the study, were used A. gigas specimens distributed in three groups according to the weight of the animals and dependence on air breathing (group 1 - low dependence; group 2 - transition; group 3 - high dependence). The hearts were collected and submitted to anatomical, ultrastructural and histological analyzes. The A. gigas ventricle presented anatomical changes among the groups, initially showing a saccular shape with fully trabeculated myocardium (group 1) and later a defi... (Complete abstract click electronic access below) / Mestre

by Tsui Kwok-wing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 188-216). / ACKNOWLEDGEMENTS --- p.ii / ABSTRACT --- p.iii / TABLE OF CONTENTS --- p.v / ABBREVIATIONS --- p.ix / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- General introduction --- p.1 / Chapter 1.2 --- Human genome project --- p.5 / Chapter 1.3 --- Organization of human genome --- p.7 / Chapter 1.4 --- Adult human heart cDNA library --- p.9 / Chapter 1.5 --- Gene expression in adult human heart --- p.10 / Chapter 1.6 --- Polymerase chain reaction --- p.12 / Chapter 1.7 --- Purification of PCR products --- p.15 / Chapter 1.8 --- Automated DNA sequencing --- p.17 / Chapter 1.9 --- Sequence analysis by electronic mail server --- p.21 / Chapter 1.10 --- Effects of agar and agarose on Vent´ёØ and Taq DNA polymerases --- p.23 / Chapter 1.11 --- Transcription factors and zinc finger proteins --- p.25 / Chapter 1.12 --- LIM domain --- p.28 / Chapter 1.13 --- Cysteine-rich intestinal protein --- p.30 / Chapter CHAPTER 2 --- MATERIALS AND METHODS / Chapter 2.1 --- Plating out the adult human heart cDNA library --- p.32 / Chapter 2.2 --- Amplification by polymerase chain reaction --- p.33 / Chapter 2.3 --- Purification of the PCR products by Millipore filters --- p.35 / Chapter 2.4 --- Elimination of the purification of the PCR products before sequencing --- p.36 / Chapter 2.5 --- Cycle sequencing --- p.37 / Chapter 2.6 --- Unicycle sequencing --- p.38 / Chapter 2.7 --- Sequencing by T7 polymerase --- p.39 / Chapter 2.8 --- Gel electrophoresis in the automated A.L.F. sequencer --- p.41 / Chapter 2.9 --- Sequence analysis by commercially available softwares --- p.42 / Chapter 2.10 --- Sequence analysis through electronic mail server --- p.44 / Chapter 2.11 --- Database for storing the result of each clone --- p.46 / Chapter 2.12 --- Effects of agar and agarose on Vent´ёØ and Taq DNA polymerase --- p.47 / Chapter 2.13 --- Mini-preparation of plasmid DNA --- p.50 / Chapter 2.14 --- Large scale preparation of plasmid DNA --- p.51 / Chapter 2.15 --- Cloning the human cysteine rich heart protein (hCRHP) into the pAED4 vector --- p.53 / Chapter 2.16 --- Expression of hCRHP in E coli --- p.56 / Chapter 2.17 --- Northern hybridization --- p.58 / Chapter 2.18 --- Partial protein sequencing of hCRHP --- p.59 / Chapter CHAPTER 3 --- RESULTS / Chapter 3.1 --- The sequencing results of adult human heart cDNA clones --- p.60 / Chapter 3.2 --- Accuracy of sequencing results --- p.63 / Chapter 3.3 --- Catalogues of genes expressed in the adult human heart --- p.65 / Chapter 3.4 --- Effects of agar and agarose on Vent´ёØ and Taq DNA polymerases --- p.94 / Chapter 3.5 --- Elimination of the purification of the PCR products before sequencing --- p.102 / Chapter 3.6 --- Sequence analysis of hCRHP --- p.104 / Chapter 3.7 --- Northern hybridization of hCRHP --- p.109 / Chapter 3.8 --- Expression of hCRHP in E. coli --- p.112 / Chapter CHAPTER 4 --- DISCUSSION / Chapter 4.1 --- Random sequencing of adult human heart cDNA clones --- p.118 / Chapter 4.2 --- Catalogues of genes expressed in the adult human heart --- p.130 / Chapter 4.3 --- Gene expression in the adult human heart --- p.137 / Chapter 4.4 --- Importance of nonhuman matches --- p.170 / Chapter 4.5 --- Effects of agar and agarose on Vent´ёØ and Taq DNA polymerases --- p.177 / Chapter 4.6 --- Elimination of the purification of the PCR products before sequencing --- p.180 / Chapter 4.7 --- The possible role of CRIP and hCRHP --- p.184 / Chapter 4.8 --- Future prospect --- p.186 / REFERENCE --- p.188