Background: Cardiovascular disease continues to remain a leading cause of morbidity and mortality in both developing and developed worlds. The sirtuin and urocortin systems are novel hormone systems in humans with an emerging role in cardiovascular physiology and pathophysiology. Through a series of studies, this thesis examines the cardiovascular effects of SRT2104 (a novel small molecule SIRT1 activator) in otherwise healthy cigarette smokers and in patients with type 2 diabetes mellitus, and of urocortins 2 and 3 in healthy volunteers and in patients with heart failure. Methods: Twenty-four otherwise healthy cigarette smokers and 15 subjects with stable type 2 diabetes participated in a randomised, double blind, placebo controlled, crossover trial and received 28 days of oral SRT2104 (2.0 g/day) or matched placebo. Plasma SRT2104 concentrations, serum lipid profile, plasma fibrinolytic factors, markers of platelet and monocyte activation and pulse wave analysis and velocity were measured at baseline and the end of each treatment period together with an assessment of forearm blood flow during intra-arterial bradykinin, acetylcholine and sodium nitroprusside infusions. The pharmacodynamic profile of urocortins 2 and 3 were assessed in 18 healthy male volunteers recruited into a series of randomised, double blind, placebo controlled, crossover studies. Bilateral forearm venous occlusion plethysmography was performed during incremental intra-arterial infusions of urocortin 2 (3.6-120 pmol/min), urocortin 3 (1.2-36 nmol/min) and substance P (2-8 pmol/min) in the presence or absence of inhibitors of cyclooxygenase (aspirin), cytochrome P450 metabolites of arachidonic acid (fluconazole) and nitric oxide synthase (L-NG-monomethyl-arginine (L-NMMA)). Finally, 12 patients with stable heart failure (New York Heart Association (NYHA) II-IV) and 10 age- and sex-matched healthy volunteers were recruited to attend once each. Bilateral forearm arterial blood flow was measured using forearm venous occlusion plethysmography during incremental intra-arterial infusions of urocortin 2 (3.6-36 pmol/min), urocortin 3 (360-3600 pmol/min) and substance P (2-8 pmol/min). Results: SRT2104 was safe and well tolerated in otherwise healthy cigarette smokers and subjects with type 2 diabetes mellitus. There were no significant differences in fibrinolytic or blood flow parameters between placebo and SRT2014. Treatment with SRT2104 was associated with a significant reduction in augmentation pressure (P=0.0273) and a trend towards improvement in the augmentation index (AIx) and corrected augmentation index (0.10 > P > 0.05 for both) without significant changes in pulse wave velocity (PWV) and time to wave reflection (Tr) (P > 0.05). Administration of SRT2104 had a favourable effect on lipid profile in otherwise healthy cigarette smokers in comparison to placebo. Urocortins 2 and 3 evoked arterial vasodilatation (P < 0.0001) without tachyphylaxis but with a slow onset and offset of action. Inhibition of nitric oxide synthase with L-NMMA reduced vasodilatation to substance P and urocortin 2 (P≤0.001 for both) but had little effect on urocortin 3 (P > 0.05). Neither aspirin nor fluconazole affected vasodilatation induced by any of the infusions (P > 0.05 for all). In the presence of all three inhibitors, urocortin 2- and urocortin 3-induced vasodilatation were attenuated (P < 0.001 for all) to a greater extent than with L-NMMA alone (P≤0.005). The vasodilatory effects of urocortins 2 and 3 were preserved in patients with heart failure. Conclusion: Activation of SIRT1 through SRT2104 improved lipid profile but did not produce demonstrable differences in vascular or platelet function with some effect on measures of arterial stiffness. Urocortins 2 and 3 appear to be potent arterial vasodilators whose vasomotor responses remained preserved in patients with heart failure and were at least partly mediated via the endothelium. Both hormone systems hold potential in their role in cardiovascular disease in man but require further studies to help translate findings of this thesis to clinical practice.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 125-128. / by Barry Leonard Wyshogrod. / M.S.

by Ling Chao Dong. / Publication date from spine. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves [102]-107). / ABSTRACT --- p.iii / ACKNOWLEDGEMENTS --- p.v / LIST OF ABBREVIATIONS --- p.vi / Chapter CHAPTER 1 --- Introduction / Chapter 1.1 --- Physiological measurement by EBI technique --- p.1 -1 / Chapter 1.2 --- Application of the EBI technique in the human thorax --- p.1 -2 / Chapter 1.3 --- Development in EIR measurement-An overview --- p.1 -4 / Chapter 1.4 --- Project objective --- p.1-7 / Chapter 1.5 --- Problems to be solved for EBI data acquisition system --- p.1-8 / Chapter 1.6 --- Main contribution of this project --- p.1 -8 / Chapter 1.7 --- Thesis outline --- p.1-9 / Chapter CHAPTER 2 --- Principles of The EBI Technique for Cardiopulmonary System / Chapter 2.1 --- The data acquisition system (DAS) --- p.2-1 / Chapter 2.1.1 --- Impedance measurement --- p.2-1 / Chapter 2.1.2 --- Data extraction and collection --- p.2-3 / Chapter 2.2 --- Constant current source --- p.2-3 / Chapter 2.3 --- Single-source multi-channel EBI controller --- p.2-5 / Chapter 2.4 --- Computer interface --- p.2-6 / Chapter 2.5 --- Tissue impedance and impedance change --- p.2-7 / Chapter 2.5.1 --- Impedance of living tissue --- p.2-7 / Chapter 2.5.2 --- Origins of impedance change --- p.2-8 / Chapter 2.6 --- Cardiovascular physiology in human body --- p.2-10 / Chapter 2.6.1 --- Structure and function of the circulatory system --- p.2-10 / Chapter 2.6.2 --- Principles of hemodynamics in pulmonary circulation --- p.2-12 / Chapter 2.7 --- Clinical application of the EIR waveform --- p.2-15 / Chapter 2.7.1 --- Physiological basis --- p.2-15 / Chapter 2.7.2 --- Clinical application --- p.2-16 / Chapter CHAPTER 3 --- The Composition of EIR Signal / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.1.1 --- The impedance change in the transthoracic section --- p.3-1 / Chapter 3.1.2 --- Origins of impedance change in pulmonary circulation --- p.3-2 / Chapter 3.2 --- Examination of contribution of impedance sources via electrolytic tank model --- p.3-3 / Chapter 3.2.1 --- Electrolytic tank set-up --- p.3-3 / Chapter 3.2.2 --- Electrolytic tank procedure --- p.3-4 / Chapter 3.2.3 --- Experimental results and discussion --- p.3-5 / Chapter 3.3 --- The interference behaviour via computer simulation --- p.3-8 / Chapter 3.3.1 --- 2D numerical model --- p.3-9 / Chapter 3.3.2 --- Computer simulation --- p.3-10 / Chapter 3.3.3 --- Results and discussion --- p.3-11 / Chapter 3.4 --- The variation of EIR waveform with electrode size --- p.3-12 / Chapter 3.4.1 --- An electronic model --- p.3-12 / Chapter 3.4.2 --- A simulated source of impedance change in pulmonary circuit --- p.3-16 / Chapter 3.4.3 --- Variation of EIR waveform via computer simulation --- p.3-18 / Chapter 3.4.4 --- Computer simulation results and discussion --- p.3-20 / Chapter 3.5 --- Discussions --- p.3-20 / Chapter 3.6 --- Conclusion --- p.3-21 / Chapter CHAPTER 4 --- A Guard Electrode System to Improve the EIR Measurement / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- Normal electrode system --- p.4-2 / Chapter 4.2.1 --- Normal electrode configuration --- p.4-2 / Chapter 4.2.2 --- Current-guarding technique for the constant-voltage system --- p.4-2 / Chapter 4.3 --- Electric field guarding --- p.4-3 / Chapter 4.4 --- Methods of study --- p.4-4 / Chapter 4.5 --- Results --- p.4-5 / Chapter 4.4.1 --- The change of electric field distribution with guarding --- p.4-5 / Chapter 4.4.2 --- Result from electrolytic tank simulation --- p.4-5 / Chapter 4.4.3 --- Variation of EIR waveform with/without guarding in human thorax --- p.4-6 / Chapter 4.5 --- Discussions and conclusion --- p.4-6 / Chapter CHAPTER 5 --- Human Measurements / Chapter 5.1 --- Introduction --- p.5-1 / Chapter 5.2 --- Variation of EIR waveform from normal human body --- p.5-2 / Chapter 5.2.1 --- Methods --- p.5_2 / Chapter 5.2.2 --- The variation of EIR waveform with electrode position and size --- p.5-3 / Chapter 5.3 --- Clinical observation --- p.5-4 / Chapter 5.3.1 --- What is PTMV --- p.5-4 / Chapter 5.3.2 --- Observing EIR waveform during the PTMV operation --- p.5-5 / Chapter 5.3.3 --- Results and discussion --- p.5-5 / Chapter 5.4 --- EIR for use in PTMV operation --- p.5-7 / Chapter 5.4.1 --- Conventional diagnostic and monitoring methods for PTMV --- p.5-7 / Chapter 5.4.2 --- The characteristic of EIR waveform with mitral stenosis --- p.5-7 / Chapter 5.4.3 --- Use of EIR as an assessing/monitoring tool for PTMV operation --- p.5-8 / Chapter 5.4.4 --- Methodology in this study --- p.5-8 / Chapter 5.4.5 --- Result and discussion --- p.5-9 / Chapter 5.5 --- Conclusion --- p.5-10 / Chapter CHAPTER 6 --- Recapitulation and Topic for Future Investigation / Chapter 6.1 --- Recapitulation --- p.6-1 / Chapter 6.2 --- Topics for future investigation --- p.6-3 / Chapter 6.2.1 --- Improvement to the DAS --- p.6-3 / Chapter 6.2.1 --- Data analysis for PTMV --- p.6-3 / REFERENCES --- p.R-1 / APPENDICES / Chapter A. --- Circuit diagram of electrical bio-impedance source simulator --- p.A-l / Chapter B. --- Circuit diagram of the electrical bio-impedance detector --- p.A-2 / Chapter C. --- Circuit diagram of multi-channel controller for multi-EBI detection --- p.A-3 / Chapter D. --- List of publications --- p.A-4

Submitted by Natalia Vieira (natalia.vieira@famerp.br) on 2016-05-30T22:07:06Z No. of bitstreams: 1 gildocavalherijunior_dissert.pdf: 207579 bytes, checksum: 1c1253f01337aa19bb5bb3919cfdebbc (MD5) / Made available in DSpace on 2016-05-30T22:07:06Z (GMT). No. of bitstreams: 1 gildocavalherijunior_dissert.pdf: 207579 bytes, checksum: 1c1253f01337aa19bb5bb3919cfdebbc (MD5) Previous issue date: 2007-05-22 / Introduction: Hemodynamic abnormalities and range of ankle motion reduction have been described in chronic venous disorders. Objective: The aim of this study was to correlate venous hemodynamics measured by air-plethysmography and range of ankle motion assessed by goniometry with clinical classes of “CEAP classification” based on clinical manifestation (C), etiologic factors (E), anatomic distribution of disease (A), and underlying pathophysiologic findings (P). Method: One hundred and forty-two white women were recruited and matched by age: group I = C0 e C1 (n= 24); group II = C2 (n= 30); group III = C3 (n= 27); group IV = C4 (n= 23); group V = C5 (n= 20); group VI = C6 (n= 18). Differences between groups were compared through analysis of variance (ANOVA), Bonferroni, Kruskal-Wallis and Dun tests, p-value = 5%. Results: The range of ankle motion was significantly reduced after C5. Venous filling index was significantly reduced after C2, ejection fraction and residual volume fraction after C4. Conclusion: The clinical severity of venous disease correlates with range of ankle motion reduction and hemodynamic deterioration measured by air-plethysmography. / Introdução: Na doença venosa crônica, têm sido descritas alterações hemodinâmicas e da mobilidade talocrural. Objetivo: Correlacionar os parâmetros hemodinâmicos venosos avaliados por pletismografia a ar e dados goniométricos de amplitude de movimento do tornozelo com o quadro clínico da doença venosa, utilizando-se a classificação Clínica, Etiológica, Anatômica e Fisiopatológica (CEAP). Método: Foram avaliadas 142 mulheres da raça branca, 284 membros inferiores que foram distribuídos em 6 grupos, de acordo com as classes clínicas da classificação CEAP: grupo I = C0 e C1 (n= 24); grupo II = C2 (n= 30); grupo III = C3 (n= 27); grupo IV = C4 (n= 23); grupo V = C5 (n= 20); grupo VI = C6 (n= 18). Foram realizados os exames de goniometria da articulação do tornozelo e de pletismografia a ar. Na análise estatística, utilizou-se a Análise de Variância, teste de Bonferroni, Kruskal-Wallis e de Dunn, considerando erro alfa de 5%. Resultados: Houve diferença significante da amplitude de movimento do tornozelo a partir do grupo C5 e do índice de enchimento venoso a partir de C2, da fração de ejeção e da fração de volume residual a partir de C4. Conclusão: A evolução do quadro clínico da doença venosa se correlaciona com uma redução da mobilidade do tornozelo e com alterações hemodinâmicas medidas pela plestimografia a ar.

The purpose of this research is the estimation for the trend of diastolic pressure of surgical patients utilizing non-invasive photo-plethysmography (PPG) signal. There are two major ways to measure blood pressure during medical treatment : invasive and non-invasive methods. Both them have advantages and disadvantages. For invasive method, it is used for surgical operations. Although it can response the true situation of arterial blood pressure, the damage and uncomfortable are the most disadvantages for itself. And for non-invasive method, it is convenient to use but the measurement results have lower accuracy. In this research, we try to estimate the continuous trend of diastolic pressure utilizing PPG signal. And calculate the accuracy of the results.

Mechanical ventilation saves lives, but it is an intervention fraught with the potential for serious complications. Prevention of these complications has become the focus of research and critical care in the last twenty years. This thesis presents the first use, or the application under new conditions, of three technologies that could contribute to optimization of mechanical ventilation. Optoelectronic plethysmography was used in Papers I and II for continuous assessment of changes in chest wall volume, configuration, and motion in the perioperative period. A forced oscillation technique (FOT) was used in Paper III to evaluate a novel positive end-expiratory pressure (PEEP) optimization strategy. Finally, in Paper IV, FOT in conjunction with an optical sensor based on a self-mixing laser interferometer (LIR) was used to study the oscillatory mechanics of the respiratory system and to measure the chest wall displacement. In Paper I, propofol anesthesia decreased end-expiratory chest wall volume (VeeCW) during induction, with a more pronounced effect on the abdominal compartment than on the rib cage. The main novel findings were an increased relative contribution of the rib cage to ventilation after induction of anesthesia, and the fact that the rib cage initiates post-apneic ventilation. In Paper II, a combination of recruitment maneuvers, PEEP, and reduced fraction of inspired oxygen, was found to preserve lung volume during and after anesthesia. Furthermore, the decrease in VeeCW during emergence from anesthesia, associated with activation of the expiratory muscles, suggested that active expiration may contribute to decreased functional residual capacity, during emergence from anesthesia. In the lavage model of lung injury studied in Paper III, a PEEP optimization strategy based on maximizing oscillatory reactance measured by FOT resulted in improved lung mechanics, increased oxygenation, and reduced histopathologic evidence of ventilator-induced lung injury. Paper IV showed that it is possible to apply both FOT and LIR simultaneously in various conditions ranging from awake quiet breathing to general anesthesia with controlled mechanical ventilation. In the case of LIR, an impedance map representing different regions of the chest wall showed reproducible changes during the different stages that suggested a high sensitivity of the LIR-based measurements.

Thesis (M.S.)--West Virginia University, 2003 / Title from document title page. Document formatted into pages; contains viii, 96 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 72-74).

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 109-117).

The measurement of total body volume (V) (excluding lung volume) together with total body mass (m) is required in order to determine body density (d = m/V). From this, and using certain simplifying assumptions, it is possible to derive body composition in terms of fat mass (FM) and fat free mass (FFM) for the two-compartment model. The standard method for determining body volume (and hence body composition) is the densitometric (underwater weighing) technique based on Archimedes' principle. Three variables, notably residual lung volume (RV), total body mass (m) and submerged body mass are measured. RV is normally determined using a gas dilution technique while total body mass is simply measured using an accurate weighing scale. The submerged body mass is measured while the subject is totally submerged in a tank of water. This method, although relatively accurate, requires substantial apparatus and is time consuming. An alternative method, based on a polytropic thermodynamic process, is described for body volume measurement and thereby for body composition assessment. Previous use of this method by Taylor, et al. (1985) and Gundlach and Visscher (1986) were successful, but complex in terms of operating system. The described system comprises of a Perspex, sealed chamber. A cycling piston communicates with the chamber and imposes a minute sinusoidal pressure variation which is then measured. With a subject situated inside the chamber an increased pressure variation, caused by the decreased chamber volume, is then measured and processed to yield the displaced, or body volume. Subject comfort, above all, is greatly enhanced, in comparison to the underwater weighing method. A substantial advantage of the method appears to be that RV need no longer be measured. Variables such as a rise of temperature and humidity caused by the subject, as well as pressure variations due to respiration, were expected and found. These were analyzed both theoretically and experimentally and where necessary the data were modified to account for these variables using a personal computer. Calibration and preliminary validation of the instrument has been carried out using underwater weighing, bioimpedance and skinfold analyses and the error of measurement assessed. It appears that the described plethysmographic method is capable of measuring body volume and thus compares favourably to the underwater weighing method. Even though other groups have succeeded in employing similar principles, a substantially simpler mechanism has been used here.

This study investigates how body position affects the relative contribution of the rib cage to speech breathing and voice quality. The frequently used upright and supine body positions are expanded with the addition of an inverted position as a condition. Five participants performed two speech production tasks across the three body positional conditions. The estimation of the relative contribution of the rib cage to speech breathing was obtained through respiratory inductance plethysmography (RIP). Phonation type was estimated through the usage of the α-ratio, obtained with a neck-surface accelerometer. The results between the participants suggest a pattern regarding levels of the relative contribution of the rib cage in relation to phonation type, which offers opportunities for further investigation in future research. / Den här studien undersöker hur kroppsposition påverkar det relativa bidraget av bröstkorgen för talandning och röstkvalité. Den frekventa användningen av upprät och supin kroppsposition utvidgas med en inverterad position som villkor. Fem forskningspersoner genomförde två talproduktionsuppgifter genom de tre kroppspositionsvillkoren. Uppskattningen av det relativa bidraget av bröstkorgen för talandning var erhållen genom respiratory inductance plethysmography (RIP). Fonationstyp var uppskattad genom användningen av α-ratio, erhållen med en ytligt hals-placerad accelerometer. Resultaten mellan deltagarna föreslår ett mönster för nivåer av det relativa bidraget av bröstkorgen relaterat till fonationstyp, som ger möjligheter för vidare undersökning i framtida forskning.