• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 34
  • 6
  • 4
  • 1
  • Tagged with
  • 40
  • 40
  • 24
  • 12
  • 11
  • 9
  • 8
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Salivary gland P2 nucleotide receptors structure and function studies /

Landon, Linda A. Neighbors January 1998 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Includes bibliographical references.
32

Purinergic proliferation of coronary smooth muscle : receptor cloning, up-regulation and signaling /

Shen, Jianzhong, January 2005 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 2005. / "July 2005." Typescript. Vita. Includes bibliographical references (leaves 152-167). Also issued on the Internet.
33

Underlying purinergic signaling important for monocilium-dependent signaling in ductal epithelia : implications for polycystic kidney disease

Hovater, Michael January 2006 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2006. / Title from first page of PDF file (viewed on June 30, 2007). Includes bibliographical references (p. 69-73).
34

Mecanismos de ação da suramina na cardiomiopatia do camundongo mdx / Action mechanisms of suramin on cardiomyopathy in the mdx mice

Moreira, Drielen de Oliveira, 1985- 02 November 2015 (has links)
Orientador: Maria Julia Marques / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-26T17:20:57Z (GMT). No. of bitstreams: 1 Moreira_DrielendeOliveira_D.pdf: 1797583 bytes, checksum: 467851661491c4671f42d059f14dbd53 (MD5) Previous issue date: 2015 / Resumo: A Distrofia Muscular de Duchenne (DMD) é uma doença muscular progressiva que causa falência respiratória e cardíaca resultando em morte por volta da terceira década de vida. A ausência da distrofina na DMD e no camundongo mdx, modelo experimental da doença, leva a instabilidade do sarcolema e aumento do influxo de cálcio seguido de mionecrose e fibrose. Receptores purinérgicos estão envolvidos na patogênese das distrofinopatias. A ativação destes receptores por ATP deflagra vias de sinalização secundárias que promovem a entrada de cálcio e ativam a formação de fibrose. No presente estudo, verificamos se a suramina, droga anti-fibrótica e antagonista de receptores purinérgicos, modifica o cálcio e proteínas a ele relacionadas, bem como afeta metaloproteinases e seus inibidores teciduais, no coração e no músculo diafragma de camundongos mdx, na fase mais tardia da doença (11 meses de idade). Análise de Western blotting revelou níveis elevados do receptor purinérgico P2Y2 em ambos os músculos estudados. A terapia com suramina diminui o nível deste receptor significativamente. Concomitantemente, observamos redução dos níveis do canal de cálcio ativado por estiramento (TRPC1) e do cálcio total, o que no músculo cardíaco pode explicar a redução da mionecrose (diminuição da creatina quinase cardíaca no plasma e da troponina I no miocárdio). A atividade e o nível da metaloproteinase-9 (MMP-9), principal envolvida na remodelação da matriz extracelular e formação de fibrose, estavam elevados no coração distrófico em relação ao coração normal. A suramina promoveu aumento adicional da atividade da MMP-9 e dos níveis do seu inibidor tecidual, a TIMP-1. A suramina preveniu a redução da beta-distroglicana, componente do complexo distrofina-proteínas que encontra-se reduzido no coração distrófico. De maneira geral, a suramina promoveu efeitos semelhantes no diafragma distrófico, no que se refere ao cálcio total, TRPC1, MMP-9 e TIMP-1. Estes dados sugerem que, tanto no coração quanto no diafragma distróficos, o receptor purinérgico P2Y2 desempenha papel importante em vias de sinalização relacionadas ao cálcio (através do TRPC1) e da modulação da matriz extracelular (através da MMP-9 e TIMP-1). A suramina, por ser utilizada em outras doenças humanas, com doses e efeitos colaterais já estabelecidos em humanos, tem potencial para a terapia da cardiomiopatia na DMD, merecendo atenção em estudos clínicos desta doença / Abstract: Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease that causes respiratory and cardiac failure and results in death at about 30 years of age. The lack of dystrophin in mdx mice, the experimental model of DMD, causes sarcolemmal breakdown and increased calcium influx followed by myonecrosis and fibrosis. Purinergic receptors are involved in the pathogenesis of dystrophinopathies. Activation of these receptors by ATP triggers secondary signaling pathways that promote calcium entry and activates the formation of fibrosis. In the present study, we investigated if suramin, an anti-fibrotic drug and an antagonist of purinergic receptors, modifies total calcium and calcium related-proteins and affects metalloproteinases and their tissue inhibitors in the heart and diaphragm muscle of dystrophic mice, in the later stage of the disease (11 months of age). Western blotting analysis indicated increased levels of P2Y2 purinergic receptor in the both muscles studied, which were significantly decreased by suramin. Concomitantly, suramin lead to a reduction in total calcium and in the levels of the stretch-activated calcium channel TRPC1, which may explain the reduction of cardiac necrosis (decreases heart creatine kinase in plasma and troponin I in the myocardium). The activity and level of metalloproteinase-9 (MMP-9), the main involved in remodeling of the extracellular matrix and formation of fibrosis, were elevated in the dystrophic heart compared to normal heart. Suramin promoted further increase in MMP-9 activity and in the levels of MMP-9 inhibitor TIMP-1. Suramin prevented the reduction of beta-dystroglycan, one of the main components of the dystrophin-protein complex usually reduced in dystrophic heart. In general, suramin promoted similar effects in the dystrophic diaphragm, with respect to total calcium, TRPC1, MMP-9 and TIMP-1. These data suggest that P2Y2 purinergic receptor plays an important role in signaling pathways involved in calcium regulation (via TRPC1) and modulation of extracellular matrix (via MMP-9 and TIMP-1), in cardiac and respiratory dystrophic muscles. Suramin may be a potential alternative to treat dystrophic cardiomyopathy deserving attention in clinical trials / Doutorado / Anatomia / Doutora em Biologia Celular e Estrutural
35

Differential inhibitory effect of CysLT₁ receptor antagonists on P2Y₆ receptor-mediated signaling pathway and ion transport in human bronchial epithelia.

January 2009 (has links)
Lau, Ka Hoi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 139-151). / Abstracts in English and Chinese. / DECLARATION --- p.i / ACKNOWLEDGEMENT --- p.ii / ABBREVIATIONS --- p.iii / ABSTRACT IN ENGLISH --- p.iv / ABSTRACT IN CHINESE --- p.vii / TABLE OF CONTENTS --- p.x / Chapter CHAPTER I - --- INTRODUCTION / Chapter 1.1 --- Regulation of human airway surface liquid --- p.1 / Chapter 1.2 --- Cysteinyl leukotrienes in asthma --- p.2 / Chapter 1.3 --- Cysteinyl leukotriene receptor in epithelial cells --- p.5 / Chapter 1.4 --- Particular interest on CysLT1 receptor --- p.7 / Chapter 1.5 --- Cysteinyl leukotrienes receptor antagonists --- p.10 / Chapter 1.6 --- Purinergic receptors in epithelial cells --- p.11 / Chapter 1.7 --- P2Y receptors in epithelial cells --- p.13 / Chapter 1.8 --- Signalling pathways of P2Y receptors by nucleotide stimulation --- p.15 / Chapter 1.9 --- The importance of P2Y6 receptor on inflammation --- p.17 / Chapter 1.10 --- Relation between CysLT1 receptor and P2Y receptor --- p.18 / Chapter 1.11 --- The properties of 16HBE14o- cell line --- p.21 / Chapter 1.12 --- Objectives of the present project --- p.22 / Chapter CHAPTER II - --- MATERIALS AND METHODS / Chapter 2.1 --- Solutions and chemicals --- p.23 / Chapter 2.2 --- Cell culture --- p.25 / Chapter 2.3 --- Measurement of intracellular calcium concentration ([Ca2+ ]i) with fluorescent imaging / Chapter 2.3.1 --- Preparation of 16HBE14o- cells for fluorescent imaging --- p.26 / Chapter 2.3.2 --- Measurement of [Ca2+]j with fluorescent imaging --- p.28 / Chapter 2.4 --- Measurement of short-circuit current (Isc) and transepithelial resistance with Ussing chamber / Chapter 2.4.1 --- Preparation of 16HBE14o- cells for Isc and transepithelial resistance measurement --- p.31 / Chapter 2.4.2 --- Measurement of Isc and transepithelial resistance with Ussing chamber --- p.33 / Chapter 2.5 --- Immunoblot analysis for CysLT1 and P2Y6 receptors --- p.35 / Chapter 2.6 --- Measurement of protein kinase A activity --- p.36 / Chapter 2.7 --- Data analysis --- p.37 / Chapter CHAPTER III - --- RESULTS / Chapter 3.1 --- Expressions of CysLTi and P2Y6 receptor in 16HBE14o- cell monolayers --- p.38 / Chapter 3.2 --- "Differential inhibitory effects of montelukast, pranlukast and zafirlukast to UDP on Isc and [Ca2+]i in 16HBE14o- cells" / Chapter 3.2.1 --- Effect of apical or basolateral application of UDP on Isc and [Ca2+]i --- p.41 / Chapter 3.2.2 --- Effect of montelukast to the application of UDP on Isc and [Ca2+]i --- p.48 / Chapter 3.2.3 --- Effect of pranlukast to the application of UDP on Isc and [Ca2+ ]i --- p.57 / Chapter 3.2.4 --- Effect of zafirlukast to the application of UDP on Isc and [Ca2+]j --- p.63 / Chapter 3.2.5 --- "Summary of the effects of montelukast, pranlukast, zafirlukast to UDP application on Isc and [Ca2+]i" --- p.69 / Chapter 3.3 --- Cellular mechanism(s) underlying the effect of montelukast to apical UDP application on 16HBE14o-cells / Chapter 3.3.1 --- Effect of various blockers inhibiting Ca2 226}Bؤdependent pathway on UDP-induced [Ca2+]i in the presence or absence of montelukast --- p.70 / Chapter 3.3.2 --- "Effects of montelukast, pranlukast and zafirlukast to PKA or Epac on Isc induced by apical UDP" --- p.86 / Chapter 3.4 --- "Effects of montelukast, pranlukast and zafirlukast on other P2Y receptor agonists on 16HBE14o- cells" / Chapter 3.4.1 --- "Effects of montelukast, pranlukast and zafirlukast on 2-methio-ADP-induced Isc and [Ca2+]i responses on 16HBE14o- cellsl" --- p.14 / Chapter 3.4.2 --- "Effects of montelukast, pranlukast and zafirlukast on UTP-induced Isc and [Ca2+]i responses on 16HBE14o- cells" --- p.116 / Chapter CHAPTER IV - --- DISCUSSION / Chapter 4.1 --- Differential effects of CysLT1 antagonists to P2Y6 agonist on Isc and [Ca2+]i in 16HBE14o-cells --- p.120 / Chapter 4.2 --- Possible cellular mechanism(s) underlying the effects of CysLT1 antagonists on UDP-induced [Ca2+]j increase in 16HBE14o- cells --- p.125 / Chapter 4.3 --- Possible cellular mechanism(s) underlying the effects of CysLT1 antagonists on UDP-induced Isc in 16HBE14o- cells --- p.129 / Chapter 4.4 --- Effects of CysLT1antagonists on other P2Y receptor subtypes in 16HBE14o- cells --- p.132 / Chapter 4.5 --- Summary: Possible interaction between CysLT1 antagonists and P2Y6 receptor --- p.135 / Chapter 4.6 --- Clinical implications and perspectives --- p.138 / Chapter CHAPTER V - --- REFERENCES --- p.139
36

Regulation of chloride secretion by P2Y receptors in polarized human bronchial epithelia, 16HBE14o-.

January 2007 (has links)
Wong, Miu Fong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 140-152). / Abstracts in English and Chinese. / DECLARATION --- p.i / ACKNOWLEDGEMENT --- p.ii / ABBREVIATIONS --- p.iii / ABSTRACT IN ENGLISH --- p.iv / ABSTRACT IN CHINESE --- p.vii / TABLE OF CONTENTS --- p.ix / LIST OF FIGURES --- p.xii / LIST OF TABLES --- p.xviii / Chapter CHAPTER I - --- INTRODUCTION / Chapter 1.1 --- Regulation of human airway surface liquid --- p.1 / Chapter 1.2 --- Sodium reabsorption and chloride secretion in airway epithelium --- p.3 / Chapter 1.3 --- Purinergic receptors --- p.7 / Chapter 1.4 --- P2Y receptors in epithelial cells --- p.11 / Chapter 1.5 --- Autocrine or paracrine regulation of ion transport in epithelial cells --- p.13 / Chapter 1.6 --- Signaling pathways underlying the regulation of ion transport by P2Y receptors stimulation --- p.16 / Chapter 1.7 --- The therapeutic potential of P2Y receptors in treating cystic fibrosis --- p.18 / Chapter 1.8 --- Particular interest on P2Y6 receptor as potential target for treatment of cystic fibrosis --- p.21 / Chapter 1.9 --- Properties of 16HBE14o- cell line --- p.23 / Chapter 1.10 --- Objectives of the present experiments --- p.25 / Chapter CHAPTER II - --- MATERIALS AND METHODS / Chapter 2.1 --- Solutions and Chemicals --- p.26 / Chapter 2.2 --- Cell culture --- p.28 / Chapter 2.3 --- Simultaneous measurement of short-circuit current (Isc) and intracellular calcium concentration ([Ca2+ ])i --- p.29 / Chapter 2.3.1 --- Preparation of 16HBE14o- cells for simultaneous measurement of Isc and [Ca2+]i --- p.29 / Chapter 2.3.2 --- Measurement of Isc and transepithelial resistance with Ussing chamber --- p.32 / Chapter 2.3.3 --- Simultaneous measurement of Isc and [Ca2+]i --- p.35 / Chapter 2.4 --- Measurement of protein kinase A activity --- p.38 / Chapter 2.5 --- Data analysis --- p.39 / Chapter CHAPTER III - --- RESULTS / Chapter 3.1 --- Apical and basolateral application of P2Y agonists induced Isc and [Ca2+]i responses in 16HBE14o- cells --- p.40 / Chapter 3.1.1 --- Effect of apical and basolateral application of ATP on Isc and [Ca2+̐]ư --- p.40 / Chapter 3.1.2 --- Effect of apical and basolateral application of UTP on Isc and [Ca2+̐]ư --- p.45 / Chapter 3.1.3 --- Effect of apical and basolateral application of UDP on Isc and [Ca2+̐]ư --- p.50 / Chapter 3.1.4 --- "Summary of the effects of apical and basolateral application of ATP, UTP and UDP on Isc and [Ca2+̐]ư" --- p.55 / Chapter 3.2 --- Ionic mechanisms underlying the effect of apical and basolateral UDP on 16HBE14o- cells --- p.56 / Chapter 3.2.1 --- Differential effect of apical and basolateral UDP on Isc --- p.56 / Chapter 3.2.2 --- Effect of various apical CI- channel blockers on Isc response induced by apical and basolateral application of UDP --- p.59 / Chapter 3.2.3 --- Effect of various basolateral K+ channel blockers on Isc response induced by apical and basolateral application of UDP --- p.83 / Chapter 3.3 --- Involvement of other signaling molecules or pathways in regulation of the chloride secreting response evoked by apical and basolateral UDP --- p.108 / Chapter 3.3.1 --- Effect of apical and basolateral UDP on PKA activity --- p.109 / Chapter 3.3.2 --- Effect of PKC inhibitors on Isc response induced by apical and basolateral application of UDP --- p.111 / Chapter CHAPTER IV - --- DISCUSSION / Chapter 4.1 --- Simultaneous measurement of Isc and [Ca2+ ̐]ư upon apical and basolateral application of P2Y agonists in 16HBE14o- cells --- p.125 / Chapter 4.2 --- Ionic mechanism underlying the effect of apical and basolateral UDP on 16HBE14o- cells --- p.128 / Chapter 4.2.1 --- Possible ionic mechanism for chloride secretion mediated by apical P2Y6 receptors --- p.131 / Chapter 4.2.2 --- Possible ionic mechanism for chloride secretion mediated by basolateral P2Y6 receptors --- p.133 / Chapter 4.3 --- Involvement of other possible signaling molecules or pathway underlying the action of apical and basolateral UDP --- p.135 / Chapter 4.4 --- Summary --- p.138 / Chapter CHAPTER V - --- REFERENCES --- p.140 / Publications --- p.153
37

Receptores hP2X7 requerem ânions e cátions extracelulares e a cauda C-terminal para gerar altas correntes não seletivas em oócitos de Xenopus laevis / Receptores hP2X7 requerem ânions e cátion extracelulares e a cauda C-terminal para gerar altas correntes não seletivas em oócitos de Xenopus laevis

Kmit, Arthur, 1987- 23 August 2018 (has links)
Orientador: Antônio Fernando Ribeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-23T16:58:35Z (GMT). No. of bitstreams: 1 Kmit_Arthur_M.pdf: 1478515 bytes, checksum: 34c7bf6fcce0ab6ab1b63b0927edcf98 (MD5) Previous issue date: 2013 / Resumo: O receptor purinérgico P2X7 é um canal iônico permeável a cátions pertencente da família P2X (P2X1-P2X7). Ele é ativado por altas concentrações (100?M - 1000?M) de ATP (Adenosine 5?-triphosphate), apresentando duas distintas respostas: 1) uma rápida ativação do canal, 2) uma segunda ativação, lenta e continua, que gera largos poros na membrana celular, permeáveis a grande moléculas (900 Da). O receptor P2X7 está envolvido em processos como morte celular, formação de células gigantes e secreção de citocinas como IL-1? e está predominantemente presente em células imunes. Neste estudo foi examinado como as altas correntes do P2X7 são geradas e qual o mecanismo necessário para serem ativadas em oócitos de Xenopus laevis. Os oócitos foram cirurgicamente retirados de uma rã adulta de Xenopus laevis e injetamos o cRNA do P2X7 para expressa-los na membrana celular. Medimos a condutância através da técnica de Voltage Clamp (TEVC). A incubação dos Oócitos superexpressos com P2X7 em BABTA-AM demonstrou que o Ca2+ extracelular, e não intracelular, é necessário para gerar altas correntes não seletivas através do P2X7, e a reposição de íons extracelular (Cl- e Na+) demonstrou regula-las. A mutação de truncamento da cauda C-terminal na proteína P2X7 gerou uma corrente menor após a estimulação com 1mM de ATP. E ainda três bloqueadores de canais o Ácido Tânico, o AO1 e o NPPB inibiram significativamente as correntes geradas pelo P2X7. Nós concluímos que (i) Os oócitos de Xenopus que expressam P2X7 produzem altas correntes não seletivas após estimulação com ATP, (ii) A ativação do P2X7 requer tanto o influxo de Ca2+ e a cauda C-terminal, e (iii) as correntes do P2X7 são regulados por cátions e ânions extracelulares / Abstract: The purinergic P2X7 receptor is an ion channel permeable to cations which belong to the P2X family (P2X1-P2X7). It is activated by high concentrations (100?M - 1000?M) of ATP (adenosine 5'-triphosphate), presenting two distinct responses: 1) a rapid activation of the channel, 2) a second activation, slow and continuous, which generates a large pore in the cell membrane permeable to large molecules (900 Dalton). The P2X7 receptor is involved in processes such as cell death, giant cell formation and secretion of cytokines such as IL-1? and is present predominantly on immune cells. In this study we examined how the P2X7 high currents are generated and what is the mechanism required to be activated in Xenopus laevis oocytes. Oocytes were surgically removed from an adult frog Xenopus laevis and injected with cRNA to express the P2X7 in the cell membrane. We measure the conductance through the Voltage Clamp technique (TEVC). Incubation of oocytes overexpressed with P2X7 receptors in BABTA-AM demonstrated that extracellular Ca2+, and do not intracellular, it is necessary to generate nonselective high currents through P2X7, and replacing extracellular ions (Cl- and Na+) showed regulate them. The truncation mutation in C-terminal tail of the P2X7 protein generated a smaller current after stimulation with 1 mM ATP. And three channel blockers Tannic Acid, AO1 and NPPB significantly inhibited the generated currents by P2X7. We conclude that (i) Xenopus oocytes expressing P2X7 produce a nonselective high currents after stimulation with ATP (ii) Activation of the P2X7 requires both the influx of Ca2+ and C-terminal tail, and (iii) the currents of the P2X7 are regulated by extracellular cations and anions / Mestrado / Saude da Criança e do Adolescente / Mestre em Ciências
38

Avaliação das variantes genéticas funcionais trombogênicas relacionadas ao receptor plaquetário P2Y12 e à metaloprotease ADAMTS13 em pacientes apresentando doença arterial coronariana / Functionally genetic thrombogenic variants related to P2Y12 platelet receptor and metaloprotease ADAMTS13 in coronary disease patients

Schettert, Isolmar Tadeu 18 April 2008 (has links)
Variantes genéticas trombogênicas podem aumentar o risco de eventos adversos em pacientes com coronariopatia crônica. Estudos prévios demonstraram que o Haplótipo H2 do gene do receptor P2Y12 apresenta uma maior agregação plaquetária e está associado com a presença de isquemia arterial periférica. A metaloprotease ADAMTS13 é responsável pela clivagem do fator de von Willebrand e recentemente foi associada com doença isquêmica coronariana. O objetivo deste trabalho foi avaliar o efeito das variantes genéticas funcionais trombogênicas dos Haplótipos H1 e H2 do receptor plaquetário P2Y12 e dos polimorfismos C1342G (Q448E), C1852G (P618A) e C2699T (A900V) da metaloprotease ADAMTS13 em 611 pacientes com doença arterial coronariana multiarterial com função ventricular preservada, acompanhados por um período de 05 anos no ensaio clínico do projeto MASS II (Medical, Angioplasty, or Surgery Study II) em relação aos eventos morte, infarto agudo do miocárdio, angina refratária necessitando um novo procedimento e acidente vascular cerebral. Neste estudo, a avaliação dos Haplótipos H1 e H2 nos pacientes do MASS II não encontrou diferença entre estes haplótipos e os eventos estudados. A análise dos polimorfismos da ADAMTS13 não encontrou associação entre os polimorfismos e os eventos estudados, exceto para a variante genética T2699 (Val900) que está associada com o evento morte (OR: 1,67 95%IC: 1-2,78, p= 0,049) e morte por causa cardiovascular (OR: 2,23 95%IC: 1,2-3,94, p=0,004) e apresenta uma diminuição na sobrevida livre de morte por causa cardíaca para os portadores do genótipo TT relacionado à este polimorfismo. A análise dos haplótipos e das combinações alélicas destes polimorfismos não apresentou associação com eventos ou com a sobrevida livre dos eventos nestes pacientes. / Thrombotic genetic variants could improve the risk of adverse events related to coronary arterial disease (CAD). P2Y12 platelet receptor H2 haplotype showed higher aggregation index and a positive association was described between such genetic variant and peripheral artery disease. DAMTS13 is a metaloprotease responsible to von Willebrand factor cleavage recently found correlated to CAD. We tested the genetic variants P2Y12 receptor H1 and H2 haplotypes and ADAMTS13 polymorphisms C1342G (Q448E), C1852G (P618A) and C2699T (A900V) in a group of 611 patients enrolled in the Medical, Angioplasty, or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease (CAD) and preserved left ventricular function in a follow up period of 05 years. The incidence of the end points of death and death from cardiac causes, myocardial infarction, refractory angina requiring revascularization and cerebrovascular accident was determined for P2Y12 H1 and H2 haplotypes and ADAMTS polymorphisms. In our study, we did not disclose any association between H1 or H2 haplotype groups regarding the incidence of any of the studied cardiovascular end-points. The association of ADAMTS13 genotypes and cardiovascular events did not showed any association between C1342G (Q448E), C1852G (P618A) variants and cardiovascular end points. Our date provide a strong association between T2699 variant and increased risk to death (OR: 1,67 CI: 1-2,78, p= 0,049) and cardiac death (OR: 2,23 CI: 1,2-3,94, p=0,004) in a population with CAD. The allelic combinations and haplotypes obtained from ADAMTS13 polymorphisms were not associated to cardiac end points and survival differences between MASS II patients.
39

Avaliação das variantes genéticas funcionais trombogênicas relacionadas ao receptor plaquetário P2Y12 e à metaloprotease ADAMTS13 em pacientes apresentando doença arterial coronariana / Functionally genetic thrombogenic variants related to P2Y12 platelet receptor and metaloprotease ADAMTS13 in coronary disease patients

Isolmar Tadeu Schettert 18 April 2008 (has links)
Variantes genéticas trombogênicas podem aumentar o risco de eventos adversos em pacientes com coronariopatia crônica. Estudos prévios demonstraram que o Haplótipo H2 do gene do receptor P2Y12 apresenta uma maior agregação plaquetária e está associado com a presença de isquemia arterial periférica. A metaloprotease ADAMTS13 é responsável pela clivagem do fator de von Willebrand e recentemente foi associada com doença isquêmica coronariana. O objetivo deste trabalho foi avaliar o efeito das variantes genéticas funcionais trombogênicas dos Haplótipos H1 e H2 do receptor plaquetário P2Y12 e dos polimorfismos C1342G (Q448E), C1852G (P618A) e C2699T (A900V) da metaloprotease ADAMTS13 em 611 pacientes com doença arterial coronariana multiarterial com função ventricular preservada, acompanhados por um período de 05 anos no ensaio clínico do projeto MASS II (Medical, Angioplasty, or Surgery Study II) em relação aos eventos morte, infarto agudo do miocárdio, angina refratária necessitando um novo procedimento e acidente vascular cerebral. Neste estudo, a avaliação dos Haplótipos H1 e H2 nos pacientes do MASS II não encontrou diferença entre estes haplótipos e os eventos estudados. A análise dos polimorfismos da ADAMTS13 não encontrou associação entre os polimorfismos e os eventos estudados, exceto para a variante genética T2699 (Val900) que está associada com o evento morte (OR: 1,67 95%IC: 1-2,78, p= 0,049) e morte por causa cardiovascular (OR: 2,23 95%IC: 1,2-3,94, p=0,004) e apresenta uma diminuição na sobrevida livre de morte por causa cardíaca para os portadores do genótipo TT relacionado à este polimorfismo. A análise dos haplótipos e das combinações alélicas destes polimorfismos não apresentou associação com eventos ou com a sobrevida livre dos eventos nestes pacientes. / Thrombotic genetic variants could improve the risk of adverse events related to coronary arterial disease (CAD). P2Y12 platelet receptor H2 haplotype showed higher aggregation index and a positive association was described between such genetic variant and peripheral artery disease. DAMTS13 is a metaloprotease responsible to von Willebrand factor cleavage recently found correlated to CAD. We tested the genetic variants P2Y12 receptor H1 and H2 haplotypes and ADAMTS13 polymorphisms C1342G (Q448E), C1852G (P618A) and C2699T (A900V) in a group of 611 patients enrolled in the Medical, Angioplasty, or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease (CAD) and preserved left ventricular function in a follow up period of 05 years. The incidence of the end points of death and death from cardiac causes, myocardial infarction, refractory angina requiring revascularization and cerebrovascular accident was determined for P2Y12 H1 and H2 haplotypes and ADAMTS polymorphisms. In our study, we did not disclose any association between H1 or H2 haplotype groups regarding the incidence of any of the studied cardiovascular end-points. The association of ADAMTS13 genotypes and cardiovascular events did not showed any association between C1342G (Q448E), C1852G (P618A) variants and cardiovascular end points. Our date provide a strong association between T2699 variant and increased risk to death (OR: 1,67 CI: 1-2,78, p= 0,049) and cardiac death (OR: 2,23 CI: 1,2-3,94, p=0,004) in a population with CAD. The allelic combinations and haplotypes obtained from ADAMTS13 polymorphisms were not associated to cardiac end points and survival differences between MASS II patients.
40

Orthodontic Mechanotransduction and the Role of the P2X7 Receptor

Viecilli, Rodrigo F. January 2009 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The first part of the study describes the development of a microCT based engineering model to study orthodontic responses. The second part investigated the relationship between orthodontic stimulus, root resorption and bone modeling. It was hypothesized that stress magnitudes are insufficient to portray the mechanical environment and explain the clinical response; directions also play a role. An idealized tooth model was constructed for finite element analysis. The principal stress magnitudes and directions were calculated in tipping and translation. It was concluded that within the same region of root, PDL and bone, there can be compression in one structure, tension in another. At a given point in a structure, compression and tension can coexist in different directions. Magnitudes of compression or tension are typically different in different directions. Previously published data presenting only stress magnitude plots can be confusing, perhaps impossible to understand and/or correlate with biological responses. To avoid ambiguities, a reference to a principal stress should include its predominant direction. Combined stress magnitude/direction results suggest that the PDL is the initiator of mechanotransduction. The third part of this project tested the role of the P2X7 receptor in the dentoalveolar morphology of C57B/6 mice. P2X7R KO (knockout) mice were compared to C57B/6 WT to identify differences in a maxillary molar and bone. Tooth dimensions were measured and 3D bone morphometry was conducted. No statistically significant differences were found between the two mouse types. P2X7R does not have a major effect on alveolar bone or tooth morphology. The final part examines the role of the P2X7 receptor in a controlled biomechanical model. Orthodontic mechanotransduction was compared in wild-type (WT) and P2X7R knock-out (KO) mice. Using Finite Element Analysis, mouse mechanics were scaled to produce typical human stress levels. Relationships between the biological responses and the calculated stresses were statistically tested and compared. There were direct relationships between certain stress magnitudes and root resorption and bone formation. Hyalinization and root and bone resorption were different in WT and KO. Orthodontic responses are related to the principal stress patterns in the PDL and the P2X7 receptor plays a significant role in their mechanotransduction.

Page generated in 0.0557 seconds