Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Vita. "August 2005" Includes bibliographical references.

Orientadores: Fernanda Klein Marcondes, Pedro Duarte Novaes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-16T16:16:47Z (GMT). No. of bitstreams: 1 Guzzoni_Vinicius_M.pdf: 984751 bytes, checksum: ee30bc1a29a47fa0be69646bf0ecf92f (MD5) Previous issue date: 2010 / Resumo: Os riscos à saúde decorrentes do consumo de esteróides anabólicos androgênicos constituem um problema de saúde pública. Em estudo anterior desenvolvido por nosso grupo de pesquisa, foi observado que o decanoato de nandrolona cancelou os efeitos vasculares adaptativos promovidos pelo treinamento físico resistido, em aorta torácica de ratos, sugerindo uma ação inibitória sobre a síntese de óxido nítrico. Visando elucidar os mecanismos envolvidos nestes efeitos, os objetivos do presente estudo foram: analisar a sensibilidade in vitro da aorta torácica ao efeito vasodilatador da acetilcolina (ACh), a espessura da parede vascular, a concentração tecidual de óxido nítrico (NO) e espécies reativas de oxigênio (EROx), em aorta torácica isolada de ratos Wistar divididos em 4 grupos experimentais: não-treinado + veículo; treinado + veículo; não-treinado + nandrolona; treinado + nandrolona. Após o período de adaptação, o treinamento físico resistido consistiu de sessões de saltos em meio líquido com sobrecarga de peso (4 séries, 10 repetições, 50-70% peso corporal, 5 dias por semana, 6 semanas). Dois dias após a última sessão de treinamento, os animais foram sacrificados por decapitação e a aorta torácica foi isolada para a obtenção de três anéis, os quais foram utilizados para obtenção da curva concentração-efeito à ACh in vitro, avaliação in vitro da produção de óxido nítrico (ON) e de espécies reativas de oxigênio (EROx), e para análise da espessura da camada média. Os dados foram analisados por ANOVA bifatorial seguido por Tukey considerando como nível de significância 5%. Animais treinados apresentaram aumento significativo na espessura da camada média da aorta torácica em relação aos respectivos grupos não-treinados. Anéis aórticos de ratos não treinados tratados com veículo ou nandrolona apresentaram relaxamento de 100% em resposta à ACh, enquanto em anéis isolados de ratos treinados tratados com veículo e nandrolona observou-se relaxamento de 79 e 51%, respectivamente. A aorta torácica de ratos treinados apresentaram menor produção de ON em relação a ratos não-treinados. A aorta isolada de ratos tratados com anabolizante apresentaram menor produção de ACh em relação ao tecido de ratos tratados com veículo. O treinamento reduziu a produção de EROx na aorta torácica de animais treinados tratados com veículo, em relação ao grupo não treinado, sem alteração em animais tratados com nandrolona. Os dados obtidos indicam que altas doses de nandrolona induziram disfunção endotelial em ratos submetidos a treinamento físico resistido. / Abstract: The risk-benefit of androgenic-anabolic steroid abuse in elite athletes has been of great corcern for researchers. Nandrolone decanoate was previously observed to inhibit the adaptative vascular effects in the thoracic aorta of rats under resistance training, probably due to an inhibitory effect on the nitric oxide synthesis. The aim of this in vitro study was to analyze the thoracic aorta sensibility to acetylcholine vasodilator effect, considering the vascular media layer thickness, the bioavailability of nitric oxide (NO) and the superoxide anion production in the thoracic aorta in Male Wistar rats, aged 2 months. Animals were assigned to four groups: non-trained animals treated with vehicle (NTV); non-trained animals treated with nandrolone (NTN); trained animals treated with vehicle (TV); and trained animals treated with nandrolone (TN). After the adaptation period, animals were submitted to resistance physical training consisting of jumps in liquid ambient with overload (4 sets, 10 repetitions, 30 second rest, 50-70% body weight-load, 5 days/week, 6 weeks). Two days after the last training session, the animals were killed by decapitation and the thoracic aorta was isolated. Thoracic aorta was divided into three parts and rings were removed from the middle third of the aorta of each animal to obtain concentration-effect curves for acetylcholine (ACh). Segments obtained from the part below the middle third were processed to evaluate the production of nitric oxide (NO) and oxygen reactive species (EROx). Data were analyzed using 2-way analysis of variance (ANOVA) followed by Tukey test, at a 5% significance level. A significant increase in the final body weight was observed in the four experimental groups, while a significant decrease was found in the final body weight for the groups treated with nandrolone. Trained animals showed a significant increase in the aorta middle layer thickness compared to non-trained groups. Aortas of the rats treated with nandrolone showed a decrease in vasodilator response compared to those of rats treated with vehicle. Isolated rings of non-trained rats treated with vehicle or nandrolone revealed 100% relaxation in response to ACh, while isolated rings of the trained rats treated with vehicle and nandrolone showed relaxation of 79 and 51%, respectively. Animals treated with nandrolone presented decreased production of NO compared to those treated with vehicle. The EROx production dropped in trained rats treated with vehicle but not in those treated with nandrolone. In conclusion, the physical training protocol used in this study caused morphological, functional, and metabolic adaptations in the aorta of the rats; supraphysiological doses of nandrolone potentiated and inhibited the responses triggered by intense physical training. / Mestrado / Fisiologia Oral / Mestre em Odontologia

Orientadores: Fernanda Klein Marcondes, Maria José Costa Sampaio Moura / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T12:11:40Z (GMT). No. of bitstreams: 1 Almeida_BrunaSantos_M.pdf: 5262157 bytes, checksum: 57d130ea7459c8f4dd3452c6387ba943 (MD5) Previous issue date: 2013 / Resumo: O estresse é considerado um fator de risco para o desenvolvimento de doenças cardiovasculares e modelos animais têm sido utilizados para a compreensão dos mecanismos fisiopatológicos envolvidos nesta associação. Em estudo anterior do nosso grupo de pesquisa, a aplicação do protocolo de estresse crônico moderado e imprevisível (ECMI) em ratos induziu aumento da sensibilidade ao efeito vasoconstritor da fenilefrina, em anéis aórticos com endotélio intacto, sendo este efeito cancelado pela inibição da síntese de óxido nítrico. Estes achados sugeriam que os efeitos vasculares do ECMI estariam relacionados à diminuição na produção de óxido nítrico (ON). Aumento na inativação de ON, por exemplo, por radicais livres, também poderiam estar relacionados às alterações induzidas pelo ECMI. O objetivo deste estudo foi avaliar em ratos adultos machos, o efeito do ECMI sobre a evolução temporal da pressão arterial e sobre a produção de óxido nítrico e ânion superóxido na aorta torácica isolada. Os animais foram aleatoriamente divididos em dois grupos experimentais: Controle e Estresse (n = 15/grupo). A avaliação da pressão arterial foi realizada uma vez por semana, por pletismografia de cauda. Quinze dias após o final do protocolo de ECMI os animais foram eutanasiados por decapitação. O sangue foi coletado para posterior dosagem de corticosterona e catecolaminas, por ELISA e cromatografia líquida respectivamente. A aorta torácica foi isolada para obtenção dos anéis aórticos e realização de curva-concentração-efeito à acetilcolina, e para determinação da produção de ON e ânion superóxido pelos métodos do 4,5 diacetato de diaminufluoresceína (DAF-2) e da hidroetidina, respectivamente. A pressão arterial sistólica e diastólica dos animais estressados nas semanas 4, 5 e 6 foi maior em relação aos valores determinados no grupo controle. Quinze dias após o ECMI, ratos estressados apresentaram menor peso corporal, aumento dos níveis de corticosterona, adrenalina e noradrenalina em relação ao grupo controle. O efeito vasodilatador da acetilcolina foi significativamente menor na aorta torácica dos animais submetidos ao ECMI em relação ao grupo controle. Aortas isoladas de ratos estressados apresentaram significativa redução na concentração de óxido nítrico e aumento na concentração de ânion superóxido, em relação ao tecido isolado de animais controle. Estes resultados confirmam que o ECMI induz disfunção endotelial na aorta torácica de ratos e que este efeito está associado à redução na biodisponibilidade de ON / Abstract: Stress is considered a risk factor to cardiovascular diseases and animal protocols have been used in studies about physiopathologic mechanisms involved in this association. In a previous study, we observed increased sensitivity to the vasoconstrictor effect of phenylephrine in aortic rings with intact endothelium from rats submitted to the protocol of chronic moderate and unpredictable stress (CMUS). This effect was canceled by the inhibition of nitric oxide synthesis in vitro. These findings suggested that vascular effects of CMS could be related to decrease in the bioavailability of nitric oxide (NO). The objective of this study was to evaluate, in adult male rats, the effect of CMS on the time course of arterial blood pressure, and on the production of nitric oxide and superoxide anion in isolated thoracic aorta. The animals were randomly divided into two experimental groups: Control and Stress (n = 15/grupo). The blood pressure determination was done once a week by the tail plethysmography. Fifteen days after the end of the CMS protocol the animals were killed by decapitation. Blood was collected for posterior corticosterone and catecholamines determination by ELISA and liquid chromatography respectively. The thoracic aorta was isolated to obtain a concentration effect curve to acetylcholine and to determine the production of NO and superoxide anion by diaminufluoresceína 4.5 diacetate (DAF-2) and hidroetidina methods respectively. Systolic and diastolic blood of stressed animals at weeks 4, 5 and 6 was significantly higher compared to values determined in the control group. Fifteen days after the end of CMUS, stressed rats showed increased levels of corticosterone, adrenaline and noradrenaline in relation to the control groups. The vasodilator effect of acetylcholine was significantly lower in the thoracic aorta of rats subjected to CMUS in the control group. Sections of aorta isolated from stressed rats showed significant reduction in nitric oxide concentration and increase in the concentration of superoxide anion in comparison to control animals. These results confirm that the CMUS induced endothelial dysfunction in rat thoracic aorta, and this effect is associated with decreased bioavailability of NO / Mestrado / Fisiologia / Mestra em Biologia Funcional e Molecular

Cardiovascular disease (CVD) including atherosclerosis is the leading cause of illness and death in the United States. The American Heart Association indicated that an estimated 81,100,000 American adults have one or more types of CVD and the estimated direct and indirect cost of CVD for 2010 is $503.2 billion, which is $27.9 billion more than last year. Although the exact cause of this disease remains unsolved, previous studies have demonstrated that pro-oxidative and pro-inflammatory pathways in vascular endothelium play a critical role in early pathological events of atherosclerosis. However, the detailed molecular signaling mechanisms underlying this process are not yet completely understood. Recently, the role of interleukin-4 (IL-4) in atherogenesis became controversial and gained attention. IL-4 is a pleiotropic immunomodulatory cytokine secreted by T-helper 2 (Th2) lymphocytes, eosinophils, and mast cells. It was traditionally believed to be an anti-inflammatory cytokine. Increasing evidence, however, has suggested that IL-4 contributes to the initiation and progression of atherosclerosis by oxidative stress-mediated up-regulation of pro-inflammatory mediators such as vascular cell adhesion moledule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in vascular endothelium. 5-Lipoxygenase (5-LOX) is one of the key sources that generate reactive oxygen species (ROS) via metabolic pathways of arachidonic acid. Although 5-LOX has been implicated in the development of atherosclerosis, it remains unclear whether 5-LOX-mediated ROS generation is associated with IL-4-induced MCP-1 expression in vascular endothelium. The present study was focused on the oxidative mechanisms by which IL-4 induces vascular inflammation as well as how 5-LOX is involved in this process. The results showed that IL-4 significantly up-regulates mRNA and protein expression of MCP-1 in vascular endothelium. In addition, DHE and DCF fluorescence staining demonstrated that IL-4 increases ROS production in human vascular endothelial cells. We have also provided the first novel evidence that 5-LOX, one of the enzymes associated with arachidonic acid metabolism, is responsible for the IL-4-induced ROS generation and MCP-1 expression in human vascular endothelial cells. / Master of Science

Yes / The development of cardiovascular disease (CVD) is the main cause of death among chronic kidney disease (CKD) patients (1). Endothelial injury and dysfunction are critical steps in atherosclerosis, a major CVD (2). Increased production of reactive oxygen species (ROS) has been associated with the pathogenesis of cardiovascular diseases such as atherosclerosis, hypertension and heart failure (3). However, hydrogen peroxide (H2O2) modulates endothelial cell function by intricate mechanisms. Ambient production of O2.− and subsequently H2O2 at low levels, maintained via basal activity of pre-assembled endothelial NAD (P) H oxidases (4). Endothelial cells play an important regulatory role in the circulation as a physical barrier and as a source of a variety of regulatory substances. Dysfunction of the vascular endothelium is thus leading to atherosclerosis which is characterised by overexpression of adhesion molecule expression, comprising vascular cell adhesion molecule 1(VCAM1). This adhesion molecule has been found to be up-regulation in human atherosclerotic lesions. The aim of this study is to evaluate the effect of H2O2 on the endothelial cells adhesion molecules expression. Primary cultures of Human Umbilical Vascular Endothelial Cells (HUVECs) will be maintained in endothelial growth medium supplemented with penicillin-streptomycin and supplement mix of fetal calf serum in a 37C humidified incubator in an atmosphere of 5% v/v CO2. HUVECs will be treated with in the presence and absences of 50 μM of H 2O2 for 2, 6, 12 and 24 h. Intracellular superoxide anion production in HUVECs will be detected by using p-Nitro Blue Tetrazolium (NBT) assay to demonstrate whether H2O2 induce the generation of superoxide anions intracellularly in HUVECs. The formation of blue formazan will be measured spectrophotometrically at 570 nm. Total RNA will be extracted from non-treated and treated cells and RNA quantity and quality will be checked by OD260/280 measurements. VCAM-1 mRNA expression will be assessed using RT-PCR. Our results show that H2O2 could potentially significantly induce EC activation through increased mRNA expression of ICAM-1 adhesion molecules in cultured HUVECs. Treatment with N-acetyl cysteine (NAC) (bulk/nano form) could significantly attenuate the effect of H2O2 administration on adhesion molecule protein expression. This strongly suggests the role of ROS in the endothelial cell damage sustained. Future work is to find reliable methods to test endothelial function. Non-invasive studies such as brachial ultrasound testing are also needed to determine its predictive value as a potential predictor for cardiovascular disease.

Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 6 uppsatser.

Thesis (MSc)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Pre-eclampsia is a condition unique to pregnancy and primarily affects the maternal and placental vascular endothelium. It has significant morbidity and mortality consequences for both mother and infant. Despite global research into the aetiology of the condition, the cause for this condition remains unknown. Several factors, including a strong family history of hypertension in pregnancy point to a familial or genetic component in the pathophysiology of this complication. The purpose of this research project was to investigate candidate genes implicated in endothelial damage. Common methylene-tetra-hydrofolate reductase (MTHFR) gene mutations C677T and A1298C, factor V Leiden mutation R506Q and prothrombin mutation A20210G were investigated in 50 patients with an uncomplicated pregnancy outcome (controls) and 350 patients with various clinical manifestations of preeclampsia, including severe, early onset forms and abruptio placentae. Fasting homocystein levels were determined biochemically on all participants. In addition, 126 consecutive pregnant patients were recruited at booking, fasting lipograms were performed on them as well as mutation screening of 7 common mutations in the low-density lipoprotein receptor gene. This was correlated with eventual pregnancy outcome, and those with an uncomplicated outcome were selected as an additional control group. A significant association between hyperhomocysteinaemia and early onset severe pre-eclampsia could be demonstrated. Mutant allele T of the C677T mutation could be associated with hyperhomocysteinaemia but not with pre-eclampsia whilst mutant allele C of mutation A1298C demonstrated a significant correlation with diastolic blood pressure. In addition, combined heterozygosity for these mutations may serve as a marker for abruptio placentae. / ENGLISH ABSTRACT: Pre-eklampsie is 'n hipertensiewe toestand uniek aan menslike swangerskap en dit affekteer hoofsaaklik die vaskulêre endoteel. Die toestand hou ernstige morbiditeit en mortaliteit vir beide ma en baba in en na jare se navorsing is die oorsaak van hierdie toestand steeds onbekend. Epidemiologiese studies toon 'n duidelike familiële verband aan wat die vermoede laat ontstaan dat daar 'n onderliggende genetiese aspek tot die ontwikkeling van die siektetoestand is. Die doel van hierdie navorsingsprojek was om gene te ondersoek wat geïmpliseer word in endoteel skade. Twee algemene mutasies, C677T en A1298C in die MTHFR geen asook faktor V Leiden R506Q en protrombien A20210G mutasies is ontleed in 50 pasiënte met 'n ongekompliseerde swangerskapsverloop en in 350 pasiënte met 'n swangerskap gekompliseer deur verskillende kliniese manifestasies van die siekteproses, insluitende vroeë aankoms erge pre-eklampsie en abruptio placentae. Op alle pasiënte is ook 'n vastende homosistiën vlak biochemies bepaal. 'n Verdere 126 opeenvolgende pasiënte is gewerf tydens hulle eerste besoek aan die voorgeboortekliniek en vastende lipogramme is op almal uitgevoer. Mutasie sifting vir 7 algemene mutasies in die lae-digtheids lipoproteïen reseptor geen is op hierdie groep gedoen en die resultaat is met die uiteindelike swangerskapsuitkoms gekorreleer. Pasiënte met 'n uitkoms ongekompliseer deur hipertensie is gekies om deel te wees van 'n verdere kontrolegroep. Daar was 'n betekenisvolle verband tussen hiperhomositiënemie en erge, vroeë aankoms pre-eklampsie. Die T alleel van die C677T mutasie is geassosieer met hiperhomosistiënemie maar nie met pre-eklampsie nie. Die C alleel van die A 1298C mutasie toon 'n betekenisvolle verband met diastoliese bloeddruk. Gekombineerde heterosigositeit vir beide MTHFR mutasies kan 'n moontlike merker vir abruptio placentae wees.

published_or_final_version / Surgery / Doctoral / Doctor of Philosophy