O objetivo desse estudo foi avaliar o comprometimento de pequenas vias aéreas na Fibrose Pulmonar Idiopática (FPI) analisando curvas Pressão- Volume (PV) do sistema respiratório. Coletamos curvas PV de doze pacientes antes da biopsia pulmonar, que confirmou FPI em sete pacientes e Pneumonite de Hipersensibilidade em cinco. Todas as curvas foram ajustadas com modelo sigmóide, V = a + b / (1 + e -(P-c/d)), e exponencial V = A - B . e -k.P (aplicado apenas à parte superior). O modelo exponencial, apesar do bom ajuste à parte superior, não representou a parte inicial da curva, gerando parâmetros sem significado. O modelo sigmóide ajustou bem toda a curva e gerou parâmetros com significado fisiológico, que sugerem a presença de colapso de pequenas vias aéreas na FPI. / The objective of this study was to evaluate small airways compromise in Idiopathic Pulmonary Fibrosis (IPF) using pressure-volume (PV) curves of the respiratory system. We collected PV curves from twelve patients before lung biopsy, which confirmed IPF in seven patients and Hipersensitivity Pneumonia in five. All curves were fitted with a sigmoid model, V = a + b / (1 + e -(P-c/d)), and an exponential model, V = A - B . e -k.P (applied only to the superior part of the curve). The exponential model, despite having a good fit to the superior part of the curve, did not represent the initial part, and yielded parameters with no physiological meaning. The sigmoid model had a good fit to the entire curve and yielded parameters with physiological meaning, suggesting the presence of small airways collapse in IPF.

The relationship between the endocannabinoid system in the renal medulla and the long-term regulation of blood pressure is not well understood. To investigate the possible role of the endocannabinoid system in renomedullary interstitial cells, mouse medullary interstitial cells (MMICs) were obtained, cultured and characterized for their responses to treatment with a selective inhibitor of fatty acid amide hydrolase (FAAH), PF-3845. Treatment of MMICs with PF-3845 increased cytoplasmic lipid granules detected by Sudan Black B staining and multilamellar bodies identified by transmission electron microscopy. HPLC analyses of lipid extracts of MMIC culture medium revealed a 205nm-absorbing peak that showed responsiveness to PF-3845 treatment. The biologic activities of the PF-3845-induced product (PIP) isolated by HPLC were investigated in anesthetized, normotensive surgically-instrumented mice. Intramedullary and intravenous infusion of PIP at low dose rates (0.5-1 AU/10 min) stimulated diuresis and natriuresis, whereas at higher doses, these parameters returned toward baseline but mean arterial pressure (MAP) was lowered. Whereas intravenous bolus doses of PIP stimulated diuresis, GFR and medullary blood flow (MBF) and reduced or had no effect on MAP, an intraperitoneal bolus injection of PIP reduced MAP, increased MBF, and had no effect on urinary parameters. Genetic or pharmacological ablation of the cannabinoid type 1 receptors in mice completely abolished the diuretic and vasodepressor properties of intramedullary infused PIP, suggesting that the PF-3845-induced product requires the presence of CB1 receptors in order to elicit its renal effects. In a radioactive competition binding assay, using Chinese hamster ovary cells expressing CB1 receptors, PIP successfully displaced the CB1 selective inverse agonist [3H] SR141716A, revealing that the lipid extract was able to compete for binding to CB1 receptors. Finally, we investigated the tubular location of diuretic activity that the PF-3845-induced lipid fraction exhibits. In a renal function in vivo experiment, we pre-treated anesthetized mice with an intramedullary infusion of one of four well-known diuretics. This procedure was followed by an intramedullary infusion of PIP (1AU). Only inhibition of the proximal tubule sodium reabsorption diminished the diuretic activity of the PF-3845-induced product, suggesting that the lipid fraction requires a physiologically intact proximal tubular reabsorption mechanism for it to produce diuresis. These data support a model whereby PF-3845 treatment of MMICs results in increased secretion of a neutral lipid which acts directly to promote diuresis and natriuresis and indirectly through metabolites to produce vasodepression. Efforts to identify the structure of the PF-3845-induced lipid and its relationship to the previously proposed renomedullary antihypertensive lipids are ongoing.

<p>The kidney is the major organ responsible for the regulation of the composition and volume of the body fluids, which is essential for homeostasis. The glycosaminoglycan hyaluronan (HA), with extreme water-binding capacity, is present in the interstitium of the kidney with a heterogenous distribution. The importance of HA in renal water-handling is unknown and was the focus of the present investigation.</p><p>Acute water-loading in rats caused the amount of papillary HA to increase and during water deprivation, the amount was reduced. Gerbils, with extreme urine concentrating capacity, have less HA in the renal papilla in normal conditions and responded diametrically different to water-loading (reduction in HA). Renomedullary interstitial cells (RMICs), which are probably the main producers of HA in the renal medulla, were cultured at different media osmolalities to mimic the milieu of the medulla during variations in the water balance. The amount of HA found in the media was decreased at high osmolalities and increased at low osmolalities, thereby strengthening the <i>in vivo</i> results. CD44, an HA-receptor involved in the uptake and degradation of HA, was expressed on RMICs in an osmolality dependent manner. During high media osmolality, the CD44 expression increased and at lower osmolalities, the opposite occurred, probably due to the need for uptake and degradation of HA.</p><p>Renal ischemia-reperfusion injury causes a cortical accumulation of HA, up-regulation of CD44, and a depression of functional parameters. The time periods of ischemia correlated with the accumulation of HA which, in turn, was inversely correlated to GFR. Hyaluronidase injections in this setting failed to reduce HA levels and significantly improve renal function.</p><p>In conclusion, the results from the present study suggest an important role for HA and RMICs in renal water-handling and that the intrarenal distribution of HA is altered after ischemia-reperfusion injury, which correlates with renal dysfunction.</p>

The kidney is the major organ responsible for the regulation of the composition and volume of the body fluids, which is essential for homeostasis. The glycosaminoglycan hyaluronan (HA), with extreme water-binding capacity, is present in the interstitium of the kidney with a heterogenous distribution. The importance of HA in renal water-handling is unknown and was the focus of the present investigation. Acute water-loading in rats caused the amount of papillary HA to increase and during water deprivation, the amount was reduced. Gerbils, with extreme urine concentrating capacity, have less HA in the renal papilla in normal conditions and responded diametrically different to water-loading (reduction in HA). Renomedullary interstitial cells (RMICs), which are probably the main producers of HA in the renal medulla, were cultured at different media osmolalities to mimic the milieu of the medulla during variations in the water balance. The amount of HA found in the media was decreased at high osmolalities and increased at low osmolalities, thereby strengthening the in vivo results. CD44, an HA-receptor involved in the uptake and degradation of HA, was expressed on RMICs in an osmolality dependent manner. During high media osmolality, the CD44 expression increased and at lower osmolalities, the opposite occurred, probably due to the need for uptake and degradation of HA. Renal ischemia-reperfusion injury causes a cortical accumulation of HA, up-regulation of CD44, and a depression of functional parameters. The time periods of ischemia correlated with the accumulation of HA which, in turn, was inversely correlated to GFR. Hyaluronidase injections in this setting failed to reduce HA levels and significantly improve renal function. In conclusion, the results from the present study suggest an important role for HA and RMICs in renal water-handling and that the intrarenal distribution of HA is altered after ischemia-reperfusion injury, which correlates with renal dysfunction.

This thesis introduces <em>Interstitial Urbanity</em> as a strategy for addressing issues of urbanity and place within New York's peripheral developments. Driven primarily by market forces, these developer led office and condominium complexes are currently being constructed along the post-industrial shorelines of New York's outer boroughs. Interstitial urbanity proposes an urban centre: a fragment of place within a non-place settlement. The theory is manifested in the design of an interstice that sits within the Queens West development on the Long Island City waterfront. Taking the form of a multi-layered public space, the interstice is comprised of a waterfront market square flanked by a commuter train terminal and an arts centre housed in a turn of the century power plant.

This thesis introduces <em>Interstitial Urbanity</em> as a strategy for addressing issues of urbanity and place within New York's peripheral developments. Driven primarily by market forces, these developer led office and condominium complexes are currently being constructed along the post-industrial shorelines of New York's outer boroughs. Interstitial urbanity proposes an urban centre: a fragment of place within a non-place settlement. The theory is manifested in the design of an interstice that sits within the Queens West development on the Long Island City waterfront. Taking the form of a multi-layered public space, the interstice is comprised of a waterfront market square flanked by a commuter train terminal and an arts centre housed in a turn of the century power plant.

<p>Cardiac arrhythmias triggered by both reentrant and focal sources are closely correlated with regions of tissue characterized by significant structural heterogeneity. Experimental and modeling studies of electrical activity in the heart have shown that local microscopic heterogeneities which average out at the macroscale in healthy tissue play a much more important role in diseased and aging cardiac tissue which have low levels of coupling and abnormal or reduced membrane excitability. However, it is still largely unknown how various combinations of microheterogeneity in the intracellular and interstitial spaces affect wavefront propagation in these critical regimes. </p> <p>This thesis uses biophysically realistic 1-D and 2-D computer models to investigate how heterogeneity in the interstitial and intracellular spaces influence both the initiation of ectopic beats and the escape of multiple ectopic beats from a poorly coupled region of tissue into surrounding well-coupled tissue. An approximate discrete monodomain model that incorporates local heterogeneity in both the interstitial and intracellular spaces was developed to represent the tissue domain. </p> <p>The results showed that increasing the effective interstitial resistivity in poorly coupled fibers alters the distribution of electrical load at the microscale and causes propagation to become more like that observed in continuous fibers. In poorly coupled domains, this nearly continuous state is modulated by cell length and is characterized by decreased gap junction delay, sustained conduction velocity, increased sodium current, reduced maximum upstroke velocity, and increased safety factor. In inhomogeneous fibers with adjacent well-coupled and poorly coupled regions, locally increasing the effective interstitial resistivity in the poorly coupled region reduces the size of the focal source needed to generate an ectopic beat, reduces dispersion of repolarization, and delays the onset of conduction block that is caused by source-load mismatch at the boundary between well-coupled and poorly-coupled regions. In 2-D tissue models, local increases in effective interstitial resistivity as well as microstructural variations in cell arrangement at the boundary between poorly coupled and well-coupled regions of tissue modulate the distribution of maximum sodium current which facilitates the unidirectional escape of focal beats. Variations in the distribution of sodium current as a function of cell length and width lead to directional differences in the response to increased effective interstitial resistivity. Propagation in critical regimes such as the ectopic substrate is very sensitive to source-load interactions and local increases in maximum sodium current caused by microheterogeneity in both intracellular and interstitial structure.</p> / Dissertation

Calcific aortic valve disease (CAVD) occurs through multiple mutually non-exclusive mechanisms that are mediated by valvular interstitial cells (VICs). VICs undergo pathological differentiation during the progression of valve calcification; however the factors that regulate cellular differentiation are not well defined. Most commonly recognized are biochemical factors that induce pathological differentiation, but little is known regarding the biochemical factors that may suppress this process. Further, the contribution of matrix mechanics in valve pathology has been overlooked, despite increasing evidence of close relationships between changes in tissue mechanics, disease progression and the regulation of cellular response. In this thesis, the effect of matrix stiffness on the differentiation of and calcification by VICs in response to pro-calcific and anti-calcific biochemical factors was investigated. Matrix stiffness modulated the response of VICs to pro-calcific factors, leading to two distinct calcification processes. VICs cultured on the more compliant matrices underwent calcification via osteoblast differentiation, whereas those cultured on the stiffer matrices were prone to myofibroblast differentiation. The transition of fibroblastic VICs to myofibroblasts increased cellular contractility, which led to contraction-mediated, apoptosis-dependent calcification. In addition, C-type natriuretic peptide (CNP), a putative protective molecule against CAVD, was identified. CNP supressed myofibroblast and osteoblast differentiation of VICs, and thereby inhibited calcification in vitro. Matrix stiffness modulated the expression of CNP-regulated transcripts, with only a small number of CNP-regulated transcripts not being sensitive to matrix mechanics. These data demonstrate the combined effects of mechanical and biochemical cues in defining VIC phenotype and responses, with implications for the interpretation of in vitro models of VIC calcification and possibly disease devleopment. The findings from this thesis emphasize the necessity to consider both biochemical and mechanical factors in order to improve fundamental understanding of VIC biology.

Innerhalb dieser Arbeit werden die Wechselwirkungen von interstitiellem Eisen mit Defekten, wie Versetzungen und Ausscheidungen, untersucht. Dazu wurde zunächst das Löslichkeitsverhalten von Eisen im p-dotierten mc-Silizium im Temperaturbereich von 550°C bis 800°C gemessen. An Versetzungsstrukturen konnte in einigen Bereichen eine deutlich erhöhte Konzentration an gelöstem Eisen im as cut Zustand und nach dem Tempern der Probe festgestellt werden. Diese wurde mit der Struktur der Versetzungsanordnung erklärt. An vorhandenen Ausscheidungen im Silizium konnte eine Abnahme der gelösten Eisenkonzentration beobachtet werden. Die Dichte und Morphologie der Ausscheidungen haben dabei einen großen Einfluss. Der Eintrag des Eisens in das Silizium aus Tiegeln mit unterschiedlicher Reinheit während der Kristallisation wurde untersucht. Dabei zeigte sich ein deutlicher Einfluss der Tiegelreinheit auf die Konzentration am Rand des Blockes, jedoch nur einen geringen Einfluss auf die Eisenkonzentration im Blockinneren.

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2016-09-13T14:03:50Z No. of bitstreams: 1 TeseLBC.pdf: 929867 bytes, checksum: 868173c840a211d49ac2c4dfe22cfda2 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-13T19:40:23Z (GMT) No. of bitstreams: 1 TeseLBC.pdf: 929867 bytes, checksum: 868173c840a211d49ac2c4dfe22cfda2 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-13T19:40:36Z (GMT) No. of bitstreams: 1 TeseLBC.pdf: 929867 bytes, checksum: 868173c840a211d49ac2c4dfe22cfda2 (MD5) / Made available in DSpace on 2016-09-13T19:40:47Z (GMT). No. of bitstreams: 1 TeseLBC.pdf: 929867 bytes, checksum: 868173c840a211d49ac2c4dfe22cfda2 (MD5) Previous issue date: 2015-10-24 / Não recebi financiamento / The thesis presented here aims to point to studies by sociologist Alberto Guerreiro Ramos about relationships (or hierarchies) race in the decades 1940- 50, demonstrating aspects (themes, methods, categories of analysis) developed in postcolonial studies. I follow an initial hypothesis that the writings of Guerreiro Ramos constitute black thought. So I will try to show how models that inspired the author - especially phenomenology and existentialism - were mobilized in the preparation of statements of very authentic and original way. However, the context in which he produced his study of race relations was the affirmation of a way of thinking which Guerreiro Ramos little or scarcely converged. He was taking notes and incorporating that knowledge came from the blackness of the African diaspora, the process of African decolonization and other foreign references as well as debates on Brazilian development. Keep that to the extent that these mergers happened he found it difficult to read a perspective that he himself does not seem to be fully aware, namely that he operated a locus of enunciation interstitial, constituting what Hall called decentered subject. / A tese que se apresenta aqui tem por objetivo retomar os estudos do sociólogo Alberto Guerreiro Ramos sobre relações (ou hierarquias) raciais entre as décadas de 1940-50, demonstrando como ali se encontram aspectos (temas, métodos, categorias de análise) desenvolvidos nos chamados pós-coloniais. Seguirei uma hipótese inicial de que os escritos de Guerreiro Ramos constituiriam o que se poderia chamar de pensamento negro. Assim, tratarei de apresentar como modelos que inspiraram o autor – sobretudo a fenomenologia e o existencialismo – foram mobilizados na elaboração de enunciados de modo autêntico e próprio. Entretanto, o contexto nacional em que ele produzia seus estudos sobre relações raciais era de afirmação de um modo de pensar ao qual Guerreiro Ramos pouco ou raramente convergia. Ele foi tomando nota e incorporando saberes que vieram da negritude, da diáspora africana, dos processos de descolonização africana e outras referências estrangeiras, bem como dos debates sobre o desenvolvimento brasileiro. Sustento que na medida em que essas incorporações aconteciam ele encontrava dificuldades de ser lido numa perspectiva que ele mesmo parece não ter plena consciência, a saber, a de que ele operava num lócus de enunciação intersticial, constituindose naquilo que Hall denominou sujeito descentrado.