Bastante recorrente na área de Finanças Corporativas, o estudo da estrutura de capital das empresas continua despertando o interesse de muitos pesquisadores. No entanto, a maioria das existentes trata da escolha da empresa no que diz respeito ao uso de capital próprio ou de terceiros para financiar suas atividades. Entendendo que esta decisão envolve também a opção sobre que tipo de recurso de terceiro utilizar, o presente estudo analisa a composição do endividamento da empresa em relação à fonte de financiamento: se recursos privados (i.e. dívida bancária) ou públicos (i.e. títulos de dívida). Para tanto, foram estimados modelos estatísticos tendo como variáveis as informações financeiras de empresas brasileiras com ações listadas na Bolsa de Valores de São Paulo (BOVESPA) e na Sociedade Operadora do Mercado de Ativos (SOMA) e não atuantes no setor de Finanças e Seguros. Os testes foram realizados para duas amostras distintas: uma com o total de empresas e outra apenas com as empresas que efetivamente acessaram o mercado público de dívida corporativa. Foram utilizados dados em painel e três métodos de estimação: pooled, efeitos aleatórios e efeitos fixos. Os resultados apontaram que as empresas, em geral, consideram questões relativas às suas oportunidade de crescimento futuro, disponibilidade de ativos tangíveis, nível de alavancagem e lucratividade são as variáveis relevantes para a tomada de decisão sobre que tipo de dívida utilizar. Mas a partir do momento que passam a ter acesso ao mercado público, o custo da dívida passa a ser importante, assim como o total de ativos imobilizados e nível de endividamento. Tem-se ainda que optam pela dívida privada aquelas empresas com maior potencial de crescimento e mais ativos tangíveis, além de menor lucratividade e menor endividamento. No caso das empresas com dívida pública em seu balanço, quanto menor o custo da dívida privada, maior será sua importância para as mesmas. / A subject extensively studied in the Corporate Finance theme, the capital structure researches continue to motivate annalists around the world. On the other hand, the majority of the existent papers discuss the company?s choice between own capital and third parties resources used to finance its operations. As we understand that such decision also involves the option about which third parties resources to use, the present paper analysis the company?s indebtedness composition related to the financing source: private (i.e. bank debt) or public (i.e. debt bound). For this purpose, it was estimated statistics models using as variables the financial information of the listed companies at São Paulo?s Stock Exchange (BOVESPA) and at Sociedade Operadora do Mercado de Ativos (SOMA) and that not act in the Financial Sector. The tests were done for two samples: one with all the companies and the other only with the companies that effectively used public debt. The data were disposal in panel and three models were estimated: pooled, random effects and fixed effects. The results pointed out that, in general, the companies consider the variables related to future growth opportunities, tangible assets available, indebtedness level and profitability as the major relevant to choice the type of debt related to the financing source. But when the companies access the public debt market, the debt cost becomes important, as the total tangible assets and the indebtedness level. The results also show that the private debt is preferred by the companies with bigger growth opportunities and larger volume of tangible asset, and with lower profitability and indebtedness level. For the companies with public debt on their balance sheet, the lower the private debt cost, the higher its importance to them.

Introdução: O saco endolinfático tem sido apontado como o alvo das reações imuno-alérgicas da orelha interna. A prevalência de alergia em pacientes com Doença de Ménière foi estabelecida em torno de 41,6% para inalantes e 26,6% para alimentos, por Derebery em 2000, dados aumentados em relação à prevalência de alergia na população em geral, que, no Brasil, varia de 9% a 30% para inalantes e de 1% a 3% para alimentos. Objetivos: Avaliar a prevalência de reações de hipersensibilidade tipo I a inalantes e alimentos na população do setor de Otoneurologia do Hospital das Clínicas da Faculdade de Medicina de São Paulo e descrever os sintomas vestibulares dos pacientes. Casuística e método: Setenta e cinco pacientes com distúrbios do equilíbrio de origem periférica foram submetidos a questionário de caracterização clínica de sintomas cócleo-vestibulares e teste cutâneo (prick test) para 13 inalantes e 5 alimentos. Resultados: Vinte e cinco (33,3%) pacientes apresentaram prick test positivo a pelo menos um alérgeno inalante e 6 (8%) a pelo menos um alérgeno alimentar. Quatro pacientes apresentaram prick test positivo na ausência de sintomas alérgicos. Prevaleceu a queixa de tontura de caráter rotatório em proporções semelhantes entre os pacientes com prick test positivo e negativo. Conclusão: A prevalência de reações de hipersensibilidade tipo I a inalantes e a alimentos na população avaliada foi maior do que na população em geral. Os sintomas vestibulares não diferiram entre os pacientes da amostra, com prick test positivo ou negativo. No entanto, deve-se obter maior número de amostra para que os dados sejam confiáveis. / Introduction: The endolymphatic sac has been pointed out as the target of immuno-allergic reactions in the inner ear. The prevalence of allergy in patients with Ménières disease was established as approximately 41,6% for inhalants and 26,6% for food by Derebery in 2000, an increase in the data in relation to that of the prevalence of allergy in the general population, which in Brazil varies from 9% to 30% for inhalants and from 1% to 3% for food. Objectives: To evaluate the prevalence of reactions to type I hypersensitivity to inhalants and food in the population of the Otoneurological Section of the Clinics Hospital of the University of São Paulo Medicine School and to describe the vestibular symptoms of the patients. Method: Seventy-five patients with peripheral equilibrium disturbances who had answered a questionnaire of clinical characterization regarding cochlear-vestibular symptoms and undergone prick test for 13 inhalants and 5 types of food. Results: Twenty-five (33,3%) of the patients were positive for the prick test and for at least one allergen inhalant and 6 (8%) for at least one food allergen. Four patients were positive for the prick test in the absence of allergy symptoms. There was a prevalence of the complaint of rotatory dizziness in similar proportions among the patients with positive and negative prick test. Conclusion: The presence of type I hypersensitivity reactions to inhalants and food in the population evaluated was greater than in the general population. The vestibular symptoms did not differ among the patients in the sample, neither with positive or negative prick test results. However, a sample of greater number should be obtained for a higher confidence level of data results.

The purpose of this study was to examine differences between school configuration and students' academic and behavioral outcomes. The participants were eighth grade students in K-8 schools who were matched with eighth grade students in 6-8 middle schools on factors including percentage of students receiving free or reduced lunch, percentage of students receiving services for special education and English language learners, average years of teacher experience, and percentage of boys and girls in each school. Eighth grade student's standardized math and reading achievement data were collected at the school level for a 3-year period. Additionally, school-level data on suspensions and expulsions over the same 3-year period were also collected. The data were analyzed using arc-sine transformation, means, standard deviation, and a repeated-measure analysis of variance. No statistical interactions were observed between time and school type for any of the research questions. However, main effects favoring K-8 schools were found for (a) Math Test, (b) Reading Test, (c) In-school Suspensions, (d) Out-of-school Suspensions, and (e) Expulsions. These findings are interpreted with a lens towards assisting school districts as to which school configuration they should consider as it relates to the district's values and long-range goals. / 10000-01-01

Thesis advisor: Julia Elisenda Grigsby / Thesis advisor: David Treumann / In 2010, Seidel and Smith used their localization framework for Floer homologies to prove a Smith-type rank inequality for the symplectic Khovanov homology of 2-periodic links in the 3-sphere. Hendricks later used similar geometric techniques to prove analogous rank inequalities for the knot Floer homology of 2-periodic links. We use combinatorial and space-level techniques to prove analogous Smith-type inequalities for various flavors of Khovanov homology for periodic links in the 3-sphere of any prime periodicity. First, we prove a graded rank inequality for the annular Khovanov homology of 2-periodic links by showing grading obstructions to longer differentials in a localization spectral sequence. We remark that the same method can be extended to p-periodic links. Second, in joint work with Matthew Stoffregen, we construct a Z/p-equivariant stable homotopy type for odd and even, annular and non-annular Khovanov homologies, using Lawson, Lipshitz, and Sarkar's Burnside functor construction of a Khovanov stable homotopy type. Then, we identify the fixed-point sets and apply a version of the classical Smith inequality to obtain spectral sequences and rank inequalities relating the Khovanov homology of a periodic link with the annular Khovanov homology of the quotient link. As a corollary, we recover a rank inequality for Khovanov homology conjectured by Seidel and Smith's work on localization and symplectic Khovanov homology. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Mathematics.

Un entier est dit y-friable si tous ses facteurs premiers n'excèdent pas y. Les valeurs friables de formes binaires interviennent de manière essentielle dans l'algorithme de factorisation du crible algébrique (NFS). Dans cette thèse, nous obtenons des formules asymptotiques pour le nombre de représentations des entiers friables par différentes familles de polynômes. Nous considérons dans la première partie les formes binaires qui se décomposent comme produit d'une forme linéaire et d'une forme quadratique. Nous combinons pour cela le principe d'inclusion-exclusion à des idées issues de travaux sur la distribution multiplicative de certaines suites d'entiers représentés par des formes quadratiques développés par Fouvry et Iwaniec, puis Balog, Blomer, Dartyge et Tenenbaum. Dans un second temps, nous nous concentrons sur les valeurs friables de formes cubiques irréductibles. En adaptant les travaux de Heath-Brown et Moroz sur les nombres premiers représentés par de tels polynômes, nous obtenons des formules asymptotiques valides dans un vaste domaine de friabilité. Notre méthode permet également d'évaluer des moyennes sur les valeurs d'une forme cubique pour d'autres fonctions arithmétiques comprenant en particulier les fonctions de Möbius et de Liouville. Dans le dernier chapitre, nous étudions les corrélations de l'indicatrice des friables avec les nilsuites. En employant la méthode nilpotente de Green et Tao, nous en déduisons une formule pour le nombre de valeurs friables d'un produit de formes affines deux à deux affinement indépendantes / An integer is called y-friable if its largest prime factor does not exceed y. Friable values of binary forms play a central role in the integer factoring algorithm NFS (Number Field Sieve). In this thesis, we obtain some asymptotic formulas for the number of representations of friable integers by various classes of polynomials. In the first part, we focus on binary forms which split as a product of a linear form and a quadratic form. To achieve this, we combine the inclusion-exclusion principle with ideas based on works of Fouvry and Iwaniec and Balog, Blomer, Dartyge and Tenenbaum related to the distribution of some sequences of integers represented by quadratic forms. We then take a closer look at friable values of irreducible cubic forms. Extending some previous works of Heath-Brown and Moroz concerning primes represented by such polynomials, we provide some asymptotic formulas which hold in a large range of friability. With this method, we also evaluate some means over the values of an irreducible cubic form for other multiplicative functions including the Möbius function and the Liouville function. In the last chapter, we investigate the correlations between nilsequences and the characteristic function of friable integers. By using the nilpotent method of Green and Tao, our work provides a formula for the number of friable integers represented by a product of affine forms such that any two forms are affinely independent

Peptídeos sinais determinam o crescimento, desenvolvimento e defesa das plantas. RALF (Rapid Alkalinization Factor) é um peptídeo de sinalização ubíquo no reino vegetal e que está envolvido com a expansão celular. Os peptídeos RALF em arabidopsis estão organizados em uma família multigênica de 37 membros, alguns com expressão tecido-específica, outros expressos em toda a planta. Os mecanismos envolvidos na expansão celular são regulados por vários hormônios, entre os quais as citocininas. A relação existente entre os peptídeos RALF e os demais hormônios é pouco conhecida e um melhor entendimento dessa relação poderá auxiliar na modulação dos processos de crescimento e desenvolvimento vegetal por engenharia genética. O objetivo desse trabalho foi estudar a relação entre o peptídeo AtRALF e as citocininas, principalmente no que diz respeito aos efeitos de ambos no crescimento e desenvolvimento das raízes. Para isso, selecionou-se as isoformas AtRALF1, AtRALF19 e AtRALF34 que apresentam diferentes padrões de expressão. Os resultados sugerem que AtRALF19 e AtRALF34, ambas expressas em toda a planta, contribuem mais com a transdução de sinal da citocinina do que a isoforma AtRALF1, com padrão de expressão específico de raízes. Os peptídeos AtRALF19 e 34 reprimem parcialmente a expressão dos genes reguladores de resposta, ARRs tipo-A, que são reguladores negativos da via de sinalização de citocinina. / Peptides signals influence the growth, development and plant defense. RALF (Rapid Alkalinization Factor) is a ubiquitous signaling peptide in the plant kingdom and is involved in cell expansion. The RALF peptides in arabidopsis are organized in a multigene family of 37 members, some with tissue-specific expression, others expressed throughout the plant. The mechanisms involved in cellular growth are regulated by various hormones, including cytokinins. The relationship between RALF peptides and other hormones is poorly understood and a better understanding of this relationship assists in modulating the processes of plant growth and development. The aim of this work was to study the relationship of AtRALF peptide with cytokinins, especially with regard to the effects of both in the growth and development of roots. For this, we selected the AtRALF1, AtRALF19 and AtRALF34 isoforms that have different expression patterns. The results suggest that AtRALF19 and AtRALF34, both expressed throughout the plant, contribute more to cytokinin signal transduction than isoform AtRALF1, with specific expression pattern in roots. The AtRALF19 and 34 repressed the expression of type-A Arabidopsis Response Regulators (ARRs), whose products act as negative regulators of cytokinin signaling.

Glioblastoma multiforme (GBM) is the most common malignant primary brain tumour in adults. The employment of current standard of care management strategy, that is combining maximum but safe surgical resection, and concomitant chemoradiotherapy, only achieves very modest survival benefits. Antiangiogenesis is a widely studied therapeutic strategy, which restricts the tumour growth by cutting off blood supplement. Although several antiangiogenic agents are now under clinicaland preclinical trials, bevacizumab is still the only one that has been proven to be effective in the treatment of recurrent GBM. However, the clinical use of bevacizumab has encountered the emergence of drug resistance. Its therapeutic benefit is considered limited because of its single pathway targeting. Many researchers believe that the use of broad spectrum angiogenesis inhibitors may leadto better clinical outcomes by overcoming the shortcomings of bevacizumab. / Vastatin, the globular non-collagenous 1 (NC1) domain of collagen VIIIα1, was initially proved to inhibit the proliferation and migration of bovine aortic endothelial cells. Although vastatin is similar in origin to other collagen-derived antiangiogenic factors (CDAFs), its antiangiogenic capability in treatment of cancers has not been studied systematically. Our team members previously found that vastatin wasa safe and effective antiangiogenic therapeutic and a potential biomarker for liver cancer. In this thesis, I tried to explore the therapeutic potential of vastatin in treatment of GBM. / Using a recombinant adeno-associated virus mediated gene therapy, the antiangiogenic potential of vastatin was first confirmed in vitro that it inhibited proliferation, migration and tube formation of murine microvascular endothelial cells (MECs). These effects were further confirmed using another gene vector (H1) which was subsequently employed for the in vivo studies. H1 is a nanopolymer gene vector has high affinity with the folate receptors on tumour cells. Transfection ofH1/vastatin reduced MEC proliferation in a U87/MEC co-culture system, suggesting a paracrine inhibition. Mechanism studies showed that vastatin caused a wide range of changes in the global gene transcription level in MECs, indicating a broad spectrum of action. / Following the establishment of an orthotopic murine GBM model, the H1/DNA polyplexes were injected directly to the tumour area. Treatment induced a significant increase in intracranial mRNA level of the therapeutic gene. Both vastatin and endostatin, a positive control, prolonged the survivals of GBM bearing mice. Immunostaning showed that vastatin decreased microvessel density in the outer layer of the tumour, while decreased cell density and caused abnormal vessel structures inthe centre. No synergistic effect was observed when GBM was treated with the combination of H1/vastatin and temozolomide (TMZ) in this model. / Finally, the therapeutic effect of vastatin on a TMZ resistant model was studied. GBM cells with acquired TMZ resistance (ATR) were established by chronic exposure of U87 cells to TMZ. Animals grafted with the U87-ATR cells were proved to be tolerant of TMZ treatment. H1/vastatin injection significantly prolonged the survival in this model. More interestingly, H1/vastatin also resensitized these animals to TMZ treatment. Stem cell related drug resistance was supposed to be disturbed in this process. / In conclusion, the present study has demonstrated for the first time that vastatin, a broad spectrum endogenous angiogenesis inhibitor, is of therapeutic benefit in a murine orthotopic GBM model. Vastatin’s capability to reverse TMZ resistance highlights an important area for further research. / 胶质母细胞瘤(GBM)是成人最常见的恶性原发性脑肿瘤。目前的治疗手段包括了手术切除和放化疗，但是效果仍不能让人满意。与传统的化疗药不同，抗血管生成药物能通过抑制肿瘤内新血管的形成，切断血流供给，达到限制肿瘤生长的目标。贝伐单抗（Bevacizumab)是目前唯一获得批准用于临床GBM治疗的抗血管生成药物。然而Bevacizumab在临床应用中必须面对耐药性产生的问题， 而且因为Bevacizumab只单一性地阻断血管内皮生长因子相关的通路，所以它的治疗效果也受到了一定程度的限制，让肿瘤可以选择替代性的通路来获得新生血管。因此一些研究人员认为，改用多靶点或者广谱的抗血管生成药物，治疗效果应该会更好。 / Vastatin是VIII型胶原蛋白α1链上的球状非胶原裂解片断。人体内这一类的片段多被证明了具有抗血管生成的功能，它们统称为“源自胶原蛋白的抗血管生成因子”。Vastatin具有抑制牛主动脉内皮细胞增殖和迁移的作用，然而它在抗肿瘤血管生成方面的作用却没有被系统地研究过。我们之前的实验曾经发现Vastatin对肝癌模型中的血管生成具有明显的抑制效果，而本论文将对Vastatin是否同样具有治疗GBM的作用展开研究。 / 在体外，我们首先证明了重组腺相关病毒（rAAV）介导的Vastatin基因治疗能有效抑制MEC的增殖和迁移，并阻止其形成管状结构。我们同时也测试了另一种基因载体H1，以方便后续动物实验的开展。H1是一种纳米聚合物，对肿瘤细胞表面高表达的叶酸受体有高亲和力。H1 介导的Vastatin 基因治疗对肿瘤细胞和MEC都没有直接的作用，但在两种细胞的共培养体系中，Vastatin可以通过旁分泌的方式来抑制MEC的增殖。对机制的研究发现，Vastatin使MEC内基因转录的水平发生了大范围多通路的改变，说明了它的作用具有一定的广谱性。 / 实验进一步研究了Vastatin在小鼠原位GBM 模型中的作用。将H1/DNA 复合物直接注入瘤区可以明显提高颅内相应基因的转录水平。Vastatin和作为阳性对照的Endostatin都能有效地延长GBM小鼠的生存期。免疫组织化学的结果显示Vastatin 能降低肿瘤内部的微血管密度，并诱导组织坏死。这与之前报道过的Endostatin的作用相似。在同一模型上，我们还测试了Vastatin和Temozolomide(TMZ)结合给药的效果，但并没有了现明显的协同作用。 / 实验最后研究了Vastatin在TMZ耐药模型中的治疗效果。通过将U87细胞长期浸泡中含有TMZ的培养基中，我们成功地筛选出了具有TMZ耐药性的GBM细胞。用这些细胞建立的小鼠GBM模型对TMZ的作用不敏感。实验表明，H1/Vastatin基因疗法不仅能够明显延长模型小鼠的生存期，还可以逆转耐药性，使TMZ重新发挥作用。我们推测干细胞相关的耐药性的产生和维持可能在这个过程中受到了影响。 / 上述研究第一次阐明了Vastatin对GBM的治疗效果。Vastatin具有广谱的抗血管特性，能够通过作用于MEC抑制肿瘤内部新血管的生成。Vastatin不仅本身具有治疗作用，还能逆转动物模型对化疗药物的耐受性，因些具有很高的研究价值。相信对Vastatin更一步的探索不但可以拓宽我们对抗血管生成药物的理解，也可能意味着一个新的研究领域的出现。 / Li, Yi. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 102-110). / Abstracts also in Chinese. / Title from PDF title page (viewed on 05, January, 2017). / Li, Yi. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

by Mui Kin Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 97-113). / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter CHAPTER 2: --- LITERATURE REVIEW --- p.5 / Chapter 2.1 --- ION TRANSPORT SYSTEMS IN HUMAN ERYTHROCYTES --- p.6 / Chapter 2.1.1 --- "Sodium Pump (Na+,K+-ATPase)" --- p.6 / Chapter 2.1.2 --- Passive Sodium Transport Systems --- p.9 / Chapter 2.1.2.1 --- Sodium-potassium-chloride cotransport system --- p.9 / Chapter 2.1.2.2 --- Sodium-lithium Countertransport --- p.13 / Chapter 2.1.3 --- Ouabain- and Frusemide-Resistant Passive Effluxes --- p.17 / Chapter 2.2 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN ESSENTIAL HYPERTENSION --- p.17 / Chapter 2.2.1 --- "Sodium Pump (Na+, K+-ATPase) in Essential Hypertension" --- p.18 / Chapter 2.2.2 --- Sodium-Potassium-Chloride Cotransport in Essential Hypertension --- p.20 / Chapter 2.2.3 --- Sodium-Lithium Countertransport in Essential Hypertension --- p.23 / Chapter 2.2.4 --- Passive Ion Fluxes in Essential Hypertension --- p.26 / Chapter 2.2.5 --- Intracellular Sodium Concentration in Essential Hypertension --- p.26 / Chapter 2.3 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN DIABETES MELLITUS --- p.27 / Chapter CHAPTER 3: --- MATERIALS & METHODS --- p.29 / Chapter 3.1 --- MATERIALS --- p.30 / Chapter 3.1.1 --- Choline Wash Solution (CWS) --- p.30 / Chapter 3.1.2 --- Lithium Loading Solution --- p.31 / Chapter 3.1.3 --- Choline Wash Solution with Ouabain (CWS-O) --- p.31 / Chapter 3.1.4 --- Sodium Containing Medium (SCM) --- p.31 / Chapter 3.1.5 --- Sodium Free Medium (SFM) --- p.31 / Chapter 3.1.6 --- Sodium Free Medium with Bumetanide (SFM-B) --- p.32 / Chapter 3.1.7 --- Preservation Solution --- p.32 / Chapter 3.2 --- STUDY POPULATION --- p.32 / Chapter 3.2.1 --- Control Subjects --- p.35 / Chapter 3.2.2 --- Patients with Essential Hypertension --- p.35 / Chapter 3.2.3 --- Diabetic Patients --- p.35 / Chapter 3.3 --- DETERMINATION OF ERYTHROCYTE INTRACELLULAR SODIUM AND POTASSIUM CONCENTRATIONS (Naic/Kic --- p.36 / Chapter 3.3.1 --- Preparation of Erythrocytes --- p.36 / Chapter 3.3.2 --- Preparation of Haemolysates --- p.38 / Chapter 3.3.3 --- Determination of Sodium and Potassium Concentrations in Haemolysates --- p.38 / Chapter 3.3.4 --- Determination of Haemoglobin Concentration in Haemolysates --- p.38 / Chapter 3.3.5 --- Evaluation of Erythrocyte Intracellular Sodium and Potassium Concentrations --- p.39 / Chapter 3.4 --- DETERMINATION OF ERYTHROCYTE PASSIVE POTASSIUM EFFLUX --- p.39 / Chapter 3.4.1 --- Determination of Potassium Concentrations in Supernatant --- p.40 / Chapter 3.4.2 --- Evaluation of Passive Potassium Efflux --- p.40 / Chapter 3.5 --- DETERMINATION OF ERYTHROCYTE SODIUM-LITHIUM COUNTERTRANSPORT (SLC) AND LITHIUM-POTASSIUM COTRANSPORT (LPC) --- p.41 / Chapter 3.5.1 --- Lithium Loading --- p.42 / Chapter 3.5.2 --- Determination of Haematocrit --- p.42 / Chapter 3.5.3 --- Preparation of Haemolysates --- p.42 / Chapter 3.5.4 --- Determination of the Lithium Concentration in Haemolysates --- p.43 / Chapter 3.5.5 --- Determination of Lithium Efflux --- p.43 / Chapter 3.5.6 --- Evaluation of Lithium Efflux Rate --- p.43 / Chapter 3.5.7 --- Evaluation of Intracellular Lithium Concentration --- p.44 / Chapter 3.6 --- VALIDATION OF METHODOLOGY FOR DETERMINATION OF ERYTHROCYTE SODIUM TRANSPORT SYSTEMS --- p.45 / Chapter 3.6.1 --- Effect of Time Course of Lithium Efflux --- p.45 / Chapter 3.6.2 --- Intracellular Potassium Concentration and Its Effect on Ouabain- and Frusemide-Resistant Passive Potassium Efflux --- p.45 / Chapter 3.7 --- PRESERVATION OF ERYTHROCYTES FOR DETERMINATION OF SODIUM TRANSPORT SYSTEMS --- p.51 / Chapter 3.8 --- PRECISION OF THE METHOD --- p.51 / Chapter 3.9 --- STATISTICS --- p.52 / Chapter CHAPTER 4: --- RESULTS --- p.56 / Chapter 4.1 --- POPULATION CHARACTERISTICS --- p.57 / Chapter 4.2 --- ERYTHROCYTE INTRACELLULAR LITHIUM CONCENTRATIONS AFTER LITHIUM LOADING --- p.57 / Chapter 4.3 --- RELATIONSHIP BETWEEN ERYTHROCYTE ION TRANSPORT PARAMETERS AND OTHER VARIABLES --- p.58 / Chapter 4.4 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN ESSENTIAL HYPERTENSION --- p.64 / Chapter 4.5 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN PATIENTS WITH DIABETES MELLITUS --- p.64 / Chapter 4.5.1 --- NIDDM Patients without Hypertension --- p.64 / Chapter 4.5.2 --- NIDDM Patients with Hypertension --- p.65 / Chapter 4.5.3 --- NIDDM Patients with and without Hypertension --- p.65 / Chapter 4.6 --- ERYTHROCYTE SODIUM TRANSPORT SYSTEMS IN DIABETES MELLITUS PATIENTS WITH PROTEINURIA --- p.65 / Chapter 4.6.1 --- Clinical Features and Biochemistry Indices --- p.69 / Chapter 4.6.2 --- Ion Transport Systems and NIDDM Patients with Proteinuria --- p.69 / Chapter 4.7 --- EFFECTS OF TREATMENTS ON ERYTHROCYTE ION TRANSPORT SYSTEMS IN DIABETIC HYPERTENSIVE PATIENTS --- p.70 / Chapter 4.7.1 --- Effects of Diuretic Therapy --- p.70 / Chapter 4.7.2 --- Effects of Enalapril and Nifedipine Therapy --- p.74 / Chapter 4.7.3 --- Effects of Enalapril Therapy --- p.74 / Chapter 4.7.4 --- Effects of Nifedipine Therapy --- p.75 / Chapter 4.7.5 --- Comparison of the Effects of Enalapril and Nifedipine Therapy --- p.75 / Chapter CHAPTER 5: --- DISCUSSION --- p.81 / Chapter 5.1 --- SODIUM TRANSPORT IN ESSENTIAL HYPERTENSION --- p.82 / Chapter 5.1.1 --- Erythrocyte Sodium-Lithium Countertransport in Essential Hypertension --- p.82 / Chapter 5.1.2 --- Erythrocyte Sodium-Potassium Cotransport in Essential Hypertension --- p.86 / Chapter 5.1.3 --- Erythrocyte Intracellular Concentration of Sodiumin Essential Hypertension --- p.87 / Chapter 5.1.4 --- Erythrocyte Passive Potassium Efflux in Essential Hypertension --- p.90 / Chapter 5.2 --- SODIUM TRANSPORT SYSTEMS IN NON-INSULIN- DEPENDENT DIABETES MELLITUS (NIDDM) --- p.91 / Chapter 5.2.1 --- Sodium-Lithium Countertransport in Non-Insulin-Dependent Diabetes Mellitus --- p.91 / Chapter 5.2.2 --- Erythrocyte Lithium-Potassium Cotransport and Intracellular Sodium Concentration in Non-Insulin-Dependent Diabetes Mellitus --- p.93 / Chapter 5.3 --- EFFECT OF ANTIHYPERTENSIVE AGENTS ON ERYTHROCYTE SODIUM TRANSPORT SYSTEMS --- p.95 / REFERENCES --- p.98

The global prevalence of type 2 diabetes (T2DM) and obesity is increasing, with obesity the most important predisposing factor contributing to the development of T2DM. Epidemiological and genetic evidence supports a major genetic component in both multifactorial and heterogeneous disorders. The identification of disease susceptibility genes in humans could greatly assist in the elucidation of underlying pathophysiological mechanisms and allow the development of more effective preventative and therapeutic strategies for these conditions. Three candidate genes, uncoupling proteins 2 and 3 (UCP2; UCP3) and calpain 10 (CAPN10), are proposed and the rationale for their selection discussed. Gene variants were identified in UCP2 and UCP3. These variants were tested for association with T2DM, obesity and intermediate quantitative traits in a South Indian population and family collection, and also a cohort of British obese case/control subjects. No variant was associated with T2DM. However, investigations revealed positive associations with a UCP2 3'UTR 45bp Ins/Del and a novel UCP3 promoter variant (-55C/T) with variation in body mass (BMI) and fat distribution (WHR) respectively. The results support the view that uncoupling proteins may influence weight gain and hence progression to obesity/T2DM. A significant correlation with plasma leptin levels and the UCP2 Ins/Del variant might indicate one potential mechanism whereby weight could be modulated by uncoupling proteins. A linkage study in affected sibling pairs of North European descent, was negative for the putative T2DM susceptibility gene region, NIDDMI. In contrast, haplotypes of four sequence variants of a T2DM susceptibility gene (CAPN10) identified in this region positively associated with T2DM in a South Indian population. In conclusion, these investigations provide evidence that the three genes studied may contribute to susceptibility for development of T2DM or obesity. However, the findings are in agreement with the most likely genetic model for non-Mendelian complex diseases, that many genes are involved in determining susceptibility to disease with no single gene capable of determining the overall disease phenotype.

Type 2 diabetes mellitus affects over 100 million people worldwide. It is characterized by various metabolic abnormalities such as insulin resistance, aberrant insulin secretion, hyperglycaemia and a cluster of cardiovascular risk factors, including increased oxidative stress. It is associated with microvascular complications and increased potential of macrovascular disease. The aim of the studies described in this thesis was to test the hypothesis that oxidant stress contributes to an altered vascular function and impaired insulin regulation in a pre-diabetic animal model- the obese Zucker rats. The first objective was to develop new methods to measure endothelial function in animal disease models. Firstly, without autonomic control - the in situ perfused hindquarters, and secondly, with autonomic control - the in vivo Doppler ear blood flow. The obese Zucker rat was shown to have increased oxidative stress, as measured by plasma 8-epi-PGF2a,. It also had high insulin and glucose levels and impaired glucose disposal. Obese rats also had increased agonist-induced nitric oxide-dependent endothelial responses; these were further enhanced by insulin in a macrovascular preparation, but were impaired by insulin in a resistance vessel bed. Following dietary treatment with the antioxidants, the obese plasma insulin/glucose ratio was improved. However, vitamin E blunted the enhanced endothelial-dependent vasodilator responses, and decreased plasma levels of 8-epi-PGF2a. In contrast, pro-oxidant treatment with hydroquinone and buthionine-sulphoximine impaired the plasma insulin/glucose ratio, abolished endothelial hyperactivity but increased plasma 8-epi-PGF2a levels. Interestingly, fructose protected against pro-oxidant-induced increases in plasma 8-epi-PGF2a levels and further increases in glucose-induced plasma insulin. In summary the redox status in obese Zucker rats was modified with antioxidant and prooxidant treatment. This resulted in compensatory changes in glucose disposal and endothelial function. Impaired endothelial function may initiate "damage" especially in those individuals susceptible to syndrome X, leading to insulin insensitivity and vascular dysfunction in type 2 diabetes.