Desde a descoberta dos supercondutores com alta temperatura crítica, muitos estudos têm sido realizados em tomo de suas propriedades fisicas, tentando associá-Ias à supercondutividade. Átomos de oxigênio dissolvidos intersticialmente têm um papel importante na supercondutividade destes materiais, pois são capazes de mover-se com facilidade dentro da rede além de contribuírem na criação de buracos nos planos de CUO2. As medidas de atrito interno são ferramentas sensíveis ao estudo de defeitos em sólidos, em particular a mobilidade de oxigênio intersticial. Neste trabalho, foram analisadas amostras de Bi2Sr2CaCu2O8+δ da maneira como foram recebidas, recozidas e dopadas com diferentes concentrações de oxigênio não estequiométrico. Foram efetuadas medidas de espectroscopia anelástica utilizando um pêndulo de torção invertido tipo Kê, operando com freqüência de oscilação de 11 a 30 Hz, num intervalo de temperatura compreendido entre 88 e 700 K, com taxa de aquecimento de 1 K/min e vácuo em tomo de 10-5 Torr. Foram observadas estruturas de relaxação complexas para as amostras recozidas, que são reversíveis apenas com novos tratamentos de recozimento, atribuídas a possíveis transições de fase estruturais. Para as amostras dopadas com oxigênio, foram observadas estruturas de relaxação que foram atribuídas ao movimento de átomos intersticiais de oxigênio nos planos de BiO. Foi observada também uma relação entre a intensidade dos processos de relaxação e a concentração dos intersticiais presentes nestas amostras. / Since the discovery of the high critical temperature superconductors many studies have been carried out intending to associate their physical properties to the superconductivity mechanisms. The oxygen atoms interstitially dissolved in its structure have an important role in the superconductivity of these materiaIs since they have high mobility capable to move through the net contributing to the generation of holes along the CUO2 plans. The internal friction measurements are a sensitive tool to the study of defects in solids, in particular the mobility of interstitial oxygen. In this work, it had been analyzed samples of Bi2Sr2CaCu2O8+δ in the as received condition, annealed and doped with different concentrations of not stoichiometric oxygen. The anelastic spectroscopy measurements were made using a torsional inverted pendulum of the Kê type, operating with oscillation frequency between 11 and 30 Hz, the applied temperatures are in the range between 88 and 700 K, with heating rate about 1 K/min and vacuum better than 10-5 Torr. Complex structures of relaxation had been observed for the annealed samples, they are reversible only with new annealing treatments. These structures were attributed to possible structural phase transitions. For the oxygen doped samples, the relaxation structures had been attributed to the mobility of interstitial oxygen atoms in the plans of BiO. On these measurements was also observed a relation between the intensity of the relaxation processes and the concentration ofthe interstitial oxygen in these samples.

Background Idiopathic pulmonary fibrosis (IPF) is one of a number of interstitial lung diseases (ILDs) that result in extensive and chronic pulmonary fibrosis. In IPF pathology, immunological dysfunction has been identified as a contributing factor to the ongoing fibrotic process, implicating cells and mechanisms of both the innate and humoral immune response. Due to the complex and diverse range of cells and mediators involved in IPF, the pathology is still poorly understood. Evidence of complement activation through the classical pathway in IPF lungs implies a role for IgG in the pathology. The active IgG in IPF may be autoreactive in nature, as IgG that target antigens of alveolar epithelial cells have been. Two autoantibodies in IPF, anti-periplakin IgG and anti-Hsp72 IgG, have been associated with poorer prognoses in IPF patients. The association of anti-Hsp72 IgG with IPF patient outcomes has not been validated and little work has been done to study the underlying mechanisms of autoantibodies in IPF pathogenesis. Hypothesis Anti-Hsp72 IgG is associated with poorer outcomes in IPF, and may induce alveolar macrophages to exhibit a pro-fibrotic phenotype. Aims The aims were to:  Optimise an ELISA for anti-Hsp72 IgG detection and determine any association of anti-Hsp72 IgG with IPF patient outcomes  Determine the location of anti-Hsp72 IgG producing cells and detect if Hsp72-IgG complexes are present in IPF patients’ lungs  Explore a potential underlying pro-fibrotic mechanism through which anti-Hps72 IgG modulates macrophage function. Results The presence of anti-Hsp72 IgG was determined in ILD patient and healthy control bronchoalveolar lavage fluid (BALf) and serum. A novel anti-Hsp72 IgG ELISA was developed and optimised and then compared against a commercial anti-Hsp72 IgGAM ELISA which became available during the PhD. Progression in IPF was defined by a decrease of ≥10% vital capacity (VC) over twelve months. Serum anti-Hsp72 IgG(AM) did not associate with changes in VC over 12 months. In contrast, BALf anti-Hsp72 IgG(AM) concentrations were elevated in IPF non-progressors. Patients with high BALf anti-Hsp72 IgGAM, had improved survival compared patient with low anti-Hsp72 IgGAM (adjusted HR 0.39, 95% CI 0.16-0.92; p=0.032) In contrast there was no association between anti-Hsp72 IgG and survival. Detection of anti-Hsp72 IgG subtypes in the serum and BALf of IPF patients revealed no significant difference in anti-Hsp72 IgG subtype detection levels between progressors and non-progressors. BALf anti-Hsp72 IgG1 levels were associated with a significantly lower rate of decline in VC over twelve months than patients with no detectable anti-Hsp72 IgG1. The presence of Hsp72-IgG complexes was confirmed by detection in purified IgG from IPF patient BALf. Immuno-histological detection of C4d deposition in the lungs of IPF patients coincided in areas of Hsp72 expression in alveolar epithelium. Summary These findings do not validate serum and-Hsp72 IgG as a biomarker for IPF. They support a role for anti-Hsp72 IgG in IPF, but associate with decreased rates of lung function decline and increased patient survival. Data also suggests that the decreased rate of decline may be related to specific anti-Hsp72 IgG subtype expression. The immune-histological data further suggests that anti-Hsp72 IgG may be targeting Hsp72 expressed by lung epithelium. Therefore these findings support a role for immunological dysfunction in IPF, but further work is required to determine the underlying mechanism.

Orientador: Carlos Roberto Grandini / Banca: Eduardo Carlos Bianchi / Banca: Cristina de Carvalho Ares Elisei / O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp / Resumo: Os elementos intersticiais exercem uma influência significativa nas propriedades mecânicas dos materiais e seu comportamento pode ser investigado por meio de técnicas de Espectroscopia Mecânica em baixa frequência (Pêndulo de Torção). Nestas medidas, são obtidos espectros de atrito interno, que estão associados à reorientação de elementos intersticiais presentes no material ao se aplicar uma tensão mecânica (fenômeno induzido). As amostras utilizadas neste trabalho são de aço inoxidável 316L obtido comercialmente. O material foi preparado em quatro condições: como recebido, tratado termicamente e duas dopagens com pressões diferentes de nitrogênio. Para caracterizar o material foram realizadas medidas de densidade, difração de raios X, microscopia eletrônica de varredura, espectroscopia de energia dispersiva e espectroscopia mecânica. As medidas de difração de raios X e microscopia eletrônica de varredura revelam que as amostras possuem uma estrutura CFC, típica de aços austeníticos. Os espectros de atrito interno das amostras revelam algumas estruturas de relaxação em todas as condições de tratamento, medidas em três diferentes frequências. Essas estruturas foram decompostas em seus processos de relaxação constituintes, associados à reorientação induzida por tensão de elementos intersticiais, como o carbono e nitrogênio, em torno de átomos que compõem o material. A comparação dos espectros de relaxação obtidos em cada condição mostra uma perda na intensidade das estruturas após realizar sucessivas medidas. Os resultados levam a concluir que este fenômeno está relacionado com a perda de elementos intersticiais pelas amostras após o aquecimento em vácuo. / Abstract: The intersticial elements exercise a significant influence in the mechanical properties of the materials and its behavior can be investigated by techniques of mechanical spectroscopy in low frequency (Torsion Pendulum). In these measurements, are obtained internal friction spectra, which are associated to the reorientation of interstitial elements present in the material if applied a mechanical stress (induced phenomenon). The samples used in this study are commercially 316L stainless steel. The material was prepared in four conditions: as received, heat treated and doped with two different pressures of nitrogen. To characterize the material, it was made measurements of density, x-ray diffraction, scanning electronic micrsocopy, electron dispersion spectroscopy and mechanical spectroscopy. The measurements of x-ray diffraction and scanning electronic microscopy reveal that the samples have a CFC structure, typical of austenitic steels. The internal friction spectra, measured in three different frequencies, reveal several relaxation structures in all of the conditions. Those structures were decomposed in their constituent relaxation processes, associates to the stress-induced ordering of interstitial elements, as carbon and nitrogen, around atoms that compose the material. The comparason of the relaxation spectra obtained in each condition shows a loss in the intensity of the relaxation structures after successive measurements. The results take to conclude that this phenomenon is related with the loss of interstitial elements of the samples after the heating in vacuum. / Mestre

Os aços livres de intersticiais (IF) têm sido usados em todo o mundo de um modo crescente desde a década de 70. A grande aplicação deste tipo de aço é na indústria automobilística em função de sua excelente conformabilidade, aliada à característica de não envelhecimento. Estas características facilitam a produção e permitem o desenvolvimento de novos projetos. Na década de 90, a Companhia Siderúrgica Nacional (CSN) iniciou a produção em escala de materiais macios, como os aços IF através do desgaseificador à vácuo RH. Procurando aumentar a participação no mercado automotivo, foi necessário desenvolver o processo de aparamento lateral do aço IF nas Linhas de Decapagem Contínua 3 e 4 da CSN para atender a demanda dos clientes. Neste trabalho, foram identificadas variáveis que influenciam a qualidade da borda aparada lateralmente das chapas laminadas a quente e a frio, as quais estão sendo testadas e ajustadas: (1) Material do aço IF, (2) parâmetros de aparamento lateral, (3) qualidade da navalha circular de aço ferramenta e sua lubrificação,(4) velocidade da navalha circular, (5)uso ou não do push-up-roll, um equipamento auxiliar para o aparamento da borda da chapa de aço. O principal objetivo do trabalho aqui apresentado é encontrar as condições que impeçam a formação de rebarba na borda do aço IF laminado a quente e decapado após aparado lateralmente nas Linhas de Decapagem Contínua 3 e 4 da CSN. As características da apara lateral foram avaliadas por microscopia eletrônica de varredura. Análises microestruturais, bem como ensaios de tração também foram executadas em amostras coletadas nas chapas laminadas a quente e a frio para vários parâmetros definidos de aparamento lateral. / The Interstitial Free (IF) steels have been used all over the world in an increasing way since the 70 decade\'s. The great application of this type of steel is in the automobile industry in function of your excellent formability, allied to the non aging property. These characteristics facilitate the production and allow the development of new projects. In this work, it has been identified variables that influence the quality of side trimming edge of hot and cold rolled strip, which were tested and adjusted: (1) IF steel material, (2) side trimming parameters,(3) tool steel circular knife quality and your lubrication;(4) tool steel speed, (5)use or not of pushup-roll , an auxiliary equipment to the cutting edge. The main objective of the work here presented it is to find the operation conditions that impede the burr formation in the edge of hot and pickled IF steel after side trimmed in the Continuous Pickling Lines 3 and 4 at CSN. The side trimmed characteristics were assessed by scanning electron microscopy. microstructural analyses, as well as tensile tests were also performed in samples taken from the hot and cold-rolled strip for the various adopted side trimming parameters.

A demanda da indústria automobilística por aços de boa estampabilidade, para aplicação em peças expostas motivou o desenvolvimento de várias especificações de aços livres de intersticiais (IF) na Companhia Siderúrgica Nacional. A especificação de aço \"IFTi\", pertencente ao grupo de aços para estampagem extra profunda especial (CSN EEPIF), com limite de resistência < 380 MPa está, dentre todos os graus de aço processados nas linhas de laminação a frio, entre os que apresentam a maior porcentagem de desvio por marca de rebarba e outros problemas relacionados ao corte. A geração de uma rebarba com altura excessiva está relacionada a um corte de má qualidade. Durante o processo de laminação a frio essa rebarba pode aumentar ainda mais de tamanho, se desprender, marcar os cilindros de trabalho e conseqüentemente aumentar os custos de produção por desvios e troca precoce de cilindros. Nas linhas de decapagem, a tesoura de pontas final é o equipamento responsável por separar as bobinas soldadas no início do processo e definir a característica de corte das pontas e caudas das mesmas, através de corte por guilhotinamento. Visando aumentar a qualidade, produtividade, diminuir as perdas durante o processo e atender às exigências dos clientes internos e externos, foi necessário desenvolver o processo de corte por guilhotina do aço IF nas tesouras de pontas final das Linhas de Decapagem Contínua 3 e 4 da CSN. Através da simulação de corte em laboratório, usando-se a mesma velocidade de avanço e ângulo de inclinação do equipamento de campo, avaliou-se a relação entre o ajuste de folga entre navalhas e o comportamento força x deslocamento no cisalhamento. Além disso, através da análise por microscopia eletrônica de varredura (MEV) foi possível observar o efeito dos varios ajustes de folga na superfície de fratura, identificando as regiões de corte citadas na literatura e sua relação com as características microestruturais e com as propriedades do material. Constatou-se que a tensão cisalhante durante o corte diminuía a medida em que a folga aumentava de forma linear para uma faixa de folga ajustada entre 6 e 12%t em amostras de aço IF-Ti com 1,5mm de espessura. Nas micrografias feitas em MEV, observou-se que as interfaces entre penetração e fratura ficaram irregulares em todos os casos, sendo uma região intermediária, com aspecto misto entre as regiões de penetração e fratura foi relacionado ao desencontro das frentes de trincas principalmente devido ao grande ângulo de fratura. Tanto os perfis de corte quanto as superfícies de fratura mostraram que a fração da região de corte diminuía com o aumento da folga, até certo ponto, quando a partir da mudança do comportamento da tensão cisalhante, voltava a aumentar. Pode-se verificar também, que a fração da região de deformação aumentava à medida que folgas maiores eram testadas e os valores atingidos eram muito superiores as deformações esperadas para as respectivas características do tipo de corte indicado pelas regiões de penetração e fratura. Os melhores resultados de corte foram obtidos na regulagem de folga entre 4 e 8%t, com rebarbas inferiores a 1,5%t, menores frações da região de deformação e interface corte/fratura mais regulares do que nas demais faixas de folga. / The automotive industry\'s demand for high formability steels for use in exposed body panels motivated the development of several interstitial free (IF) steels specifications at Companhia Siderurgica Nacional. The \"IF-Ti\" steel specification belongs to the special deep drawing steels group (CSN EEP-IF), with yield strength <380 MPa, and among all grades of steel processed in the cold rolling lines is the one with the highest amount of deviation by burr marks and other problems related to shearing. The generation of an excessive burr height is related to a poor cut quality. During the cold rolling process the burr can increase in size, break off, mark the work rolls and therefore increase production costs per deviation and early exchange of cylinders. In the pickling lines, the exit shear is the device responsible for separating the coils welded at the beginning of the process and to define the cutting head and tail characteristics, either through guillotine cutting. Aiming to increase quality, productivity, reduce losses during the process and meet the requirements of internal and external customers, it was necessary to develop the guillotine cutting process of the IF steel sheet extremities (head and tail) in the exit shears of Continuous Pickling Lines #3 and #4 at CSN. Through the cutting simulation in the laboratory, using the same forward speed and rake angle adopted in the field equipment, was evaluated the relationship between the adjustment of clearance between blades and the behavior shear force versus displacement. In addition, through the analysis by scanning electron microscopy (SEM) it was possible to observe the effect of several settings on the fracture surface, identifying the different regions cited in the literature and its relation to the microstructural characteristics and to the material properties. It was found that the shear stress during cutting reduced as the gap increased linearly to a range between 6 and 12%t in samples of IF-Ti steel with 1.5 mm thick. In the micrographs taken by SEM, it was observed that the interfaces between burnished and fracture were irregular in all cases, where an intermediate depth, with mixed aspect between the burnished and fracture depths was related to mismatch of crack fronts mainly due to the large fracture angle. Both cut profiles as the fracture surfaces showed that the burnished depth decreased with increasing the gap to some extent, since from the behavior change of shear stress, it started to increase. It was also possible to verify that the fraction of therollover depth increased as larger gaps were tested and the values achieved were much higher than expected for the rollover characteristics of the respective type of cut indicated by the burnished and fracture depths. The best cutting results were obtained for clearance adjustment between 4 and 8%, resulting in burrs below 1.5%t, smaller rollover depth and more regular burnished/fracture interface than in other clearance ranges tested.

A terapia fotodinâmica (TFD) tem sido utilizada no tratamento de lesões neoplásicas e não-neoplásicas. Sua base é a combinação de três elementos-chave: fotossensibilizador, oxigênio molecular e luz em comprimento de onda que excite o fotossensibilizador, levando-o a gerar espécies reativas de oxigênio que causam danos à estrutura celular. Portanto, a iluminação é um dos fatores essenciais para a indução da resposta adequada. Nos casos de lesões superficiais, a iluminação é facilmente obtida através da irradiação da superfície da mesma. Contudo, no tratamento de tumores sólidos ou invasivos, é preciso recorrer à TFD intersticial, na qual fibras ópticas são inseridas no tumor. No entanto, as diferenças no perfil de emissão de luz a partir das fibras difusoras, dependem do modo de fabricação, tamanho e propriedades, o que dificulta o estabelecimento de uma dosimetria de luz apropriada. Com este estudo, buscou-se contribuir no entendimento de como a luz, emitida por uma fibra difusora, se comporta no meio túrbido, assim como no tecido biológico. Dessa forma, buscou-se prever como a luz se propaga no meio e, assim, poder estimar a dose adequada de luz que se deve entregar ao tecido para que toda uma região seja irradiada. Para isto, foi utilizada uma fibra óptica com um difusor cilíndrico de 20 mm de comprimento emissor, acoplada a um laser de diodo em 630 nm e uma fibra óptica isotrópica de coleta, para medir a intensidade de luz emitida pelo difusor em várias posições. As medidas permitiram obter uma caracterização do perfil de emissão da fibra, sendo o ar o único meio de propagação da luz nesse caso. Posteriormente à obtenção do perfil, uma solução lipídica foi utilizada como phantom de tecido biológico. As fibras foram encapadas de modo a expor somente uma seção de 1 mm de comprimento delas. Com as fibras submersas na solução do phantom, foram realizadas medidas do campo de luz gerado por este elemento de 1 mm de comprimento do difusor. A partir da caracterização da emissão do elemento, foi possível recuperar a distribuição de luz gerada por todo o difusor utilizando composições ponderadas feitas a partir deste elemento. Estas composições apresentaram melhores resultados quando foi considerada a uma prévia caracterização da fibra na ponderação da reconstrução. A TFD foi realizada em fígado de ratos sadios para a análise de uma resposta real e, com o auxílio de ferramentas computacionais, foi possível reconstruir a necrose constituída pela irradiação da fibra toda, a partir da necrose gerada por um elemento difusor de 2 mm da fibra (obtido da mesma forma que o elemento de 1 mm), com resultados também otimizados com o uso da caracterização da fibra como base para a soma ponderada. Os resultados demonstraram que, através da caracterização do perfil de iluminação da fibra difusora e da distribuição de luz em meio túrbido, foi possível definir teoricamente um padrão de necrose semelhante ao observado no modelo animal. Portanto, a reconstituição do perfil obtida possui potencial para permitir melhorias no entendimento e na dosimetria de aplicações intersticiais de luz para TFD. / Photodynamic therapy (PDT) has been used for treatment of several tumor types, and presents best results for surface lesion. Light penetration on biological tissue is one limiting factor in PDT, interfering with the treatment of invasive or solid tumors. In those cases, a possible solution is to use interstitial PDT, in which optical fibers are inserted into the tumor. Cylindrical diffusers have been used for the application of interstitial PDT. However, differences in the diffuser light emission depend on the manufacturing process, size and optical properties of the fiber, which make it difficult to establish light dosimeter. This study aims to determine the distribution of light generated by a cylindrical diffuser in a turbid medium. A solution of lipid emulsion was used as an optical phantom. An optical fiber with a cylindrical diffuser of 2 cm in length was connected to a diode laser 630 nm, and the spatial distribution of light generated by the diffuser was measured by scanning a collector optical fiber. From the measurement of the light field generated by an element (1 mm long) of a 20 mm-long cylindrical diffuser, recovery of the distribution of light generated by the entire diffuser is expected. The results obtained so far show that it is possible to reconstruct the light field of a 20 mm-long cylindrical element diffuser by measuring the light emitted simultaneously by 20 elements of 1 mm. Then, the PDT was done in rat liver to analyze a real response and, with help of computational tools, a necrosis generated by irradiation of all fiber was reconstructed, using a necrosis produced by an element 2 mm long (likewise the element 1mm long). The results showed that knowing the illumination profile of a cylindrical diffuser and the light distribution in turbid medium, it was possible to redefine a shape of necrosis from as animal model theoretically. Therefore, the reconstruction of the profile obtained has potential to improve understanding and the light dosimeter in interstitial PDT.

Idiopathic pulmonary fibrosis (IPF) is an irreversible disease of unknown etiology that involves progressive scarring of the lung tissue, leading to respiratory failure and death.1 IPF is thought to develop from repetitive lung injury and aberrant wound healing that leads to the generation of fibrous tissue rather than restoration of normal tissue.2 It has been suggested in mice that vascular leak after lung injury contributes to the development of lung fibrosis.2,3 Gadofosveset is an intravascular enhancing, gadolinium-based contrast agent used with magnetic resonance imaging (MRI) to assess a variety of biological processes in vivo because it can reversibly bind to albumin.13-14 Gadofosveset has been used to assess endothelial permeability and function, as it diffuses through the vessel walls via leaky neovessels and damaged endothelium.15 Our research group has developed a new method to assess disease activity in IPF patients using gadofosveset-enhanced lung MRI. In unpublished work, we have demonstrated that this technique can be used to generate an albumin extravasation index (AEI), and we have found that this is significantly and diffusely increased in the lung of patients with idiopathic pulmonary fibrosis compared to healthy controls.16 The AEI is a measure of the change in signal intensity post-contrast minus pre-contrast in predefined regions of interest (ROIs) in the lung parenchyma divided by post- minus pre-contrast signal intensity in the ROI in the aorta. In this study, we compared the AEI in patients with IPF to healthy control (HC) subjects and evaluated the correlation between the AEI and high-resolution computed tomography (HRCT) and pulmonary function testing (PFT). We found that IPF subjects had increased AEI values compared with HC subjects. While not statistically significant, AEI was more strongly correlated with fibrosis (interstitial abnormalities) than ground-glass (alveolar abnormalities) on HRCT. Furthermore, there was a possible correlation between AEI and change in percent predicted forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and diffusion capacity of carbon monoxide adjusted for hemoglobin (DLCO) [Hb]. Our results demonstrate that AEI calculations from gadofosveset-enhanced lung MRI are a surrogate measure of vascular leak and can potentially serve as an alternative method for predicting the clinical course and severity of IPF through its correlation with fibrosis on HRCT and pulmonary function.

Downtown Tampa, a struggling city core, will continue to struggle as it holds no true identity to its relationship with important surrounding context, as well as within itself. Evidence in the lack of inhabitable, urban spaces with the scale and comfort to support integral human activity on a day-to-day basis has resulted in the absence of a city center within downtown. One lost opportunity for downtown is its disconnection with the University of Tampa, one that could result in an activated edge condition. As UT appears vertically congruous with downtown, it has no relationship as it is separated from it by the river. The key to blurring the edge at this instance could be aided through an inhabitable, urban space activated by the neighboring student population, as well as individuals working within downtown. The site I have chosen is the existing Curtis Hixon Park and Kiley Gardens, directly across from the University, providing a wonderful opportunity to blur the disconnect. It is also situated amidst forces from all directions, including the central business district and residential areas within downtown's nucleus, thus creating an inter[positioned] quality within the site. One issue to deal with on the site is determining the manner in which the project meets the two main edges, downtown and the Hillsborough River. One source that will become a major infl uence on the concept will be that of Peter Eisenman's text "Blurred Zones: Investigations of the Interstitial." This text will allow me to understand another contemporary architect's ideas of that of the in-between. Thus, site conditions and modern culture will intertwine in the creation of an urban landscape situated within a struggling context to serve the public as a destination within downtown Tampa.

Hypertension is a critical public health issue worldwide, and in the United States, it is the leading cause of heart disease, stroke, and kidney failure, contributing to more than 1,100 deaths per day. It is proposed that the renal medulla combats increased blood pressure by releasing a neutral lipid from the lipid droplets of medullary interstitial cells, termed medullipin, which induces diuresis- natriuresis and vasodepression. The renal medulla is enriched with fatty acid lipid ethanolamides including the endocannabinoid anandamide (AEA), palmitoylethanolamide (PEA), and oleoylethanolamide (OEA), along with their primary hydrolyzing enzyme fatty acid amide hydrolase (FAAH). Our lab is investigating the relationship of these lipid ethanolamides and their metabolites to medullipin. We have shown that intramedullary infusion of AEA stimulated diuresis-natriuresis without changing mean arterial pressure (MAP) in an acute surgical model using anesthetized normotensive C57BL/6J mice. The hypothesis that infusion of a FAAH-selective inhibitor, PF-3845, would produce similar responses as exogenous AEA was tested. Intramedullary infusion of PF-3845 stimulated diuresis-natriuresis, decreased MAP, and increased lipid ethanolamide concentrations in kidney tissue in C57BL/6J mice. Since the decrease in MAP observed with PF-3845 was not consistent with the results of exogenous AEA, this study hypothesized that increased PEA concentrations in the renal medulla observed with PF-3845 produced the decrease in MAP. Therefore, the effects of PEA administration into the renal medulla were investigated. Intramedullary infusion of PEA stimulated diuresis and natriuresis without changing MAP in normotensive C57BL/6J mice. However, intramedullary PEA administration to mice made hypertensive using L-NAME, an inhibitor of nitric oxide synthase, was assessed. Intramedullary infusion of PEA stimulated diuresis, but also decreased MAP in L-NAME-induced hypertensive mice. The mechanism of PEA-induced diuresis was evaluated for the contributions of its FAAH-mediated hydrolysis and the CB1 receptor. Intramedullary infusion of PEA stimulated diuresis in FAAH knockout mice and CB1 knockout mice. The possible source of PEA in the renal medulla was investigated using renal medullary interstitial cells cultured from mice. In cultured mouse medullary interstitial cells (MMICs), treatment with PF-3845 increased cytoplasmic lipid droplets detected by Sudan Black B (SBB) staining and increased PEA in the culture medium. Physiologic stimuli that may regulate PEA production and release from MMICs were also evaluated. Increased osmolarity increased NAPE-PLD protein levels, increased SBB stained droplets in MMICs, and increased PEA concentrations in the culture medium. Overall, it is concluded that the PEA-induced diuretic and natriuretic effect is independent of FAAH-mediated hydrolysis and the CB1 receptor, and that PEA can serve as an antihypertensive regulator in the renal medulla that may be regulated by medullary interstitial cells.

<p>Fibroblasts continuously strive to organize and compact the surrounding extracellular matrix (ECM). Recent data suggest that this cellular contractility controls interstitial fluid homeostasis in loose connective tissues (CT). The aim of this thesis was to study the effects of prostaglandins on fibroblast contractility and to investigate whether fibroblasts in the interstitial CT surrounding the human endolymphatic duct (ED) can modulate inner ear fluid pressure and endolymph resorption. </p><p>Paper I shows that prostaglandin E1 (PGE₁) and prostacyclin inhibit fibroblast-mediated collagen matrix compaction <i>in vitro</i> and lower the interstitial fluid pressure <i>in vivo</i> in rat dermis. Paper II demonstrates that the inhibition of collagen matrix compaction by PGE₁ is protein kinase A-dependent. Furthermore, PGE₁ induces a complete but reversible actin depolymerization in human dermal fibroblasts by affecting the phosphorylation state of regulatory actin-binding proteins. Paper III describes that the cells of the interstitial CT encompassing the human ED are organized in a network based on intercellular- and cell-ECM contacts. Paper IV shows that two distinct cell phenotypes populate this interstitial CT: one expressing the lymph endothelial marker podoplanin and the other a fibroblast marker. Furthermore, CT cells isolated from human ED tissues exhibited the same tissue compacting properties <i>in vitro</i> as dermal fibroblasts. </p><p>In conclusion, PGE₁ inhibits fibroblast contractility by interfering with the stability and dynamics of the actin cytoskeleton, which leads to a loss of integrin-mediated adhesion to the ECM. These mechanisms are supposedly involved in edema formation in skin during inflammation and might be involved in the formation of endolymphatic hydrops in the inner ear of patients with Ménière’s disease.</p>