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  • 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.
441

Μελέτη της έκφρασης λιποκινών και του υποδοχέα CB1 των ενδοκανναβινοειδών σε περιαορτικό και επικαρδιακό λιπώδη ιστό ανθρώπου και συσχέτιση με την αθηροσκλήρωση

Σπύρογλου, Σοφία 27 December 2010 (has links)
Οι λιποκίνες αποτελούν πρωτεϊνικά προϊόντα του λιπώδους ιστού με αυτοκρινείς, παρακρινείς και ενδοκρινείς δράσεις που εμπλέκονται στην παθογένεια της καρδιαγγειακής νόσου. Η τοπική παραγωγή λιποκινών, ειδικά από τον περιαγγειακό λιπώδη ιστό, μπορεί να επηρεάσει τη φυσιολογία και την παθολογία των αγγείων. Το ενδοκανναβινοειδές σύστημα σχετίζεται με τη ρύθμιση της ενδοκρινούς λειτουργίας του λιπώδους ιστού, αλλά και με την παθογένεια της αθηροσκλήρωσης. Μελετήσαμε την έκφραση της αντιπονεκτίνης, της βισφατίνης, της λεπτίνης και των νεότερων λιποκινών χεμερίνης και βασπίνης, καθώς και του υποδοχέα ενδοκανναβινοειδών CB1 σε ανθρώπινο περιαορτικό και επικαρδιακό λιπώδη ιστό, καθώς και τη συσχέτισή τους με την αορτική και τη στεφανιαία αθηροσκλήρωση. Εφαρμόστηκε ανοσοϊστοχημική χρώση για τις λιποκίνες και τον CB1 σε δείγματα ανθρώπινου περιαορτικού, περιστεφανιαίου και επικαρδιακού λίπους της κορυφής της καρδιάς. Οι αθηροσκληρωτικές βλάβες στο παρακείμενο αγγειακό τοίχωμα αξιολογήθηκαν με βάση την κατάταξη του AHA. Οι λιποκίνες εκφράστηκαν στον περιαγγειακό και επικαρδιακό λιπώδη ιστό της κορυφής και – με εξαίρεση την αντιπονεκτίνη – στα αγγειακά λεία μυικά κύτταρα και στα αφρώδη κύτταρα των αθηροσκληρωτικών βλαβών. Ο CB1 εκφράστηκε στον περιαορτικό και επικαρδιακό λιπώδη ιστό, καθώς και στα αορτικά και στεφανιαία αγγειακά λεία μυικά κύτταρα. Η αορτική αθηροσκλήρωση συσχετίστηκε θετικά με την έκφραση της χεμερίνης, της βασπίνης, της βισφατίνης και της λεπτίνης στο περιαορτικό λίπος. Η στεφανιαία αθηροσκλήρωση συσχετίστηκε θετικά με την έκφραση της χεμερίνης και της βασπίνης στο περιστεφανιαίο λίπος. Η έκφραση της αντιπονεκτίνης στο λιπώδη ιστό συσχετίστηκε αρνητικά τόσο με την αορτική όσο και με τη στεφανιαία αθηροσκλήρωση. Η έκφραση λιποκινών στον επικαρδιακό λιπώδη ιστό της κορυφής δε συσχετίστηκε με την αθηροσκλήρωση. Επίσης, η έκφραση του CB1 δε συσχετίστηκε με την αορτική ή με τη στεφανιαία αθηροσκλήρωση. Συμπερασματικά, παρατηρήθηκε: α) διαφορετικό προφίλ έκφρασης της αντιπονεκτίνης, βισφατίνης, λεπτίνης, χεμερίνης, βασπίνης και του CB1 στον περιαορτικό, περιστεφανιαίο και επικαρδιακό λιπώδη ιστό της κορυφής, β) συσχέτιση των λιποκινών, αλλά όχι του CB1, με την αορτική ή και με τη στεφανιαία αθηροσκλήρωση, με χαρακτηριστικό τρόπο για κάθε λιποκίνη. Η τοπική παραγωγή λιποκινών ενδεχομένως επηρεάζει ποικιλοτρόπως την αθηροσκληρωτική διαδικασία σε διαφορετικές θέσεις. / Adipokines are protein products of adipose tissue with autocrine, paracrine and endocrine actions, which have been implicated in the pathogenesis of cardiovascular disease. Locally produced adipokines, especially by periadventitial adipose tissue, may affect vascular physiology and pathology. The endocannabinoid system has also been implicated in the pathogenesis of atherosclerosis and in adipose tissue endocrine function regulation. We investigated the expression of adiponectin, visfatin, leptin and novel adipokines chemerin and vaspin, as well as CB1 endocannabinoid receptor, in human periaortic and epicardial adipose tissue, as well as their correlation to aortic and coronary atherosclerosis. Standard immunohistochemical staining for the adipokines and CB1 was performed on samples of human periaortic, pericoronary and apical epicardial adipose tissue. Atherosclerotic lesions of the adjacent vascular wall were assessed using the AHA classification. Adipokines were expressed in periadventitial and apical epicardial adipose tissue and - except for adiponectin - in vascular smooth muscle cells and foam cells in atherosclerotic lesions. CB1 was expressed in periaortic and epicardial adipose tissue, as well as in aortic and coronary vascular smooth muscle cells. Aortic atherosclerosis was positively correlated with chemerin, vaspin, visfatin and leptin periaortic fat expression. Coronary atherosclerosis was positively correlated with chemerin and visfatin pericoronary fat expression. Adipose tissue adiponectin expression was negatively correlated to atherosclerosis in both locations. Expression of adipokines in apical epicardial fat was not associated to atherosclerosis. CB1 expression was not correlated with either aortic or coronary atherosclerosis. Our results show: a) a different expression pattern of adiponectin, visfatin, leptin, chemerin, vaspin and CB1 in periaortic, pericoronary and apical epicardial adipose tissue, b) a correlation of these adipokines - but not CB1 - with either aortic or coronary atherosclerosis or both in a pattern characteristic for each adipokine and suggest that locally produced adipokines might differently affect the atherosclerotic process in different locations.
442

Implication des microARNs dans la conversion des adipocytes blancs en adipocytes thermogéniques / miRNAs implication in white adipocytes conversion into thermogenic adipocytes

Giroud, Maude 16 November 2015 (has links)
La découverte récente d'adipocytes bruns fonctionnels chez les humains adultes a conduit à envisager leur utilisation afin d’augmenter la dépense énergétique dans de potentiels traitements contre l'obésité et les maladies associées. Par ailleurs, des ilots d’adipocytes bruns, appelés adipocytes "brite" (brown in white), émergent dans le tissu adipeux blanc après une exposition au froid ou une stimulation des récepteurs β3-adrénergiques. En utilisant les cellules hMADS, nous avons identifié plusieurs miARNs régulés pendant le « britening ». miR-125b et let-7i ont des niveaux d’expression plus bas dans les adipocytes « brites ». Des analyses fonctionnelles utilisant un « mimic » de miR-125b ou un inhibiteur ont révélé que miR-125b agit comme un frein sur le « brunissage » des cellules hMADS en altérant leur respiration ainsi que leur contenu mitochondrial. In vivo, nous avons montré que miR-125b et let-7i sont moins exprimés dans le tissu adipeux brun par rapport au tissu adipeux blanc. La stimulation des récepteurs β3-adrénergiques ou l'exposition au froid induit une diminution d’expression des miARNs dans les deux tissus et est associée à l'activation du tissu adipeux brun et au recrutement des adipocytes « brites ». Nous avons constaté que l’injection de miR-125b ou let-7i dans le tissu adipeux blanc sous-cutané inhibait l’expression de gènes du « brunissage » induite par la stimulation de la voie β3-adrénergique. En conclusion, nos observations ont montré que miR-125b et let-7i jouaient un rôle important dans la modulation des adipocytes « brites » et des adipocytes « bruns » en ciblant l’expression de gènes mitochondriaux et en diminuant la biogenèse mitochondriale. / The recent discovery of functional brown adipocytes in adult humans has led to the consideration of their use to increase energy expenditure in the treatment of obesity and associated metabolic disorders. Furthermore, in rodents and humans, islands of thermogenic adipocytes, termed “brite” (brown in white) adipocytes, emerge within white adipose tissue after cold exposure or β3-adrenergic receptor stimulation. Using hMADS cells, we identified several miRNAs regulated during “britening” including miR-125b and let-7i which showed lower levels in brite adipocytes. Functional analysis using miR-125b mimic or miR-125b inhibitor transfection revealed that miR-125b-5p acts as a brake of the browning of hMADS cells by impairing respiration rate as well as their mitochondrial content. miR-125b and let-7i levels were lower in brown compared to white adipose tissue. In vivo, we showed that both miRNAs levels were down regulated in mice sub-cutaneous white and brown adipose tissues upon β3-adrenergic receptors stimulation or cold exposure, which is associated with BAT activation and brite adipocyte recruitment. We found that injection of both miRNA mimics in subcutaneous white adipose tissue inhibited β3-adrenergic-induced brown adipocyte markers expression. Altogether, our observations showed that miR-125b and let-7i played an important role in the modulation of brite and brown adipocytes function targeting oxygen consumption and mitochondrial gene expression.
443

Avaliação do transplante intratecal de células tronco mesenquimais alogênicas em equinos sadios e portadores de sequelas neurológicas

Barberini, Danielle Jaqueta. January 2017 (has links)
Orientador: Rogerio Martins Amorim / Resumo: As células-tronco mesenquimais (CTM) apresentam propriedades antiinflamatórias, imunomoduladoras, neuroprotetoras e neurorregenerativas. Pela capacidade regenerativa limitada do tecido neural, o potencial terapêutico das células-tronco tem sido estudado em várias enfermidades do sistema nervoso central (SNC). Sendo assim, o objetivo deste trabalho foi avaliar a viabilidade, segurança e a resposta a transplantes intratecais sucessivos, de CTM provenientes de diversas fontes em equinos. Para isso, foram avaliados o potencial de transdiferenciação, terapêutico e o co-cultivo com líquido cefalorraquidiano (LCR) de CTM provenientes da medula óssea, tecido adiposo e cordão umbilical. Posteriormente, as CTM foram utilizadas para o transplante por via intratecal (IT) pela cisterna lombo-sacra (LS), atlanto-occipital (AO) e entre as vértebras C1-C2 em animais sadios (GS), totalizando 3 aplicações com intervalo de 30 dias. Adicionalmente as CTM foram rastreadas por cintigrafia após os transplantes pelas via AO e LS. Finalmente, as CTM foram utilizadas para o transplante IT entre as vértebras C1-C2 em animais com incoordenação motora decorrente de Mieloencefalite Equina por Protozoário (MEP) – grupo doente (GD), sob o mesmo protocolo. Todos os animais (GS e GD) foram avaliados por exame clínico e neurológico, análise hematológica e do LCR antes e após os transplantes. Os resultados demonstraram que as CTM provenientes de diversas fontes apresentaram efeitos positivos na presença de LCR,... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor
444

Origin of White and Brown Adipose Cells From Vascular Endothelium: A Dissertation

Tran, Khanh-Van T. 12 April 2012 (has links)
Obesity is associated with insulin resistance, dyslipidemia, and cardiovascular disease. The current obesity epidemic is the result of surplus energy consumption. Excess energy is stored in expanding adipose tissue. Adipose tissue growth entails the enlargement of existing adipocytes, the formation of new fat cells from preexisting progenitors, and the coordinated development of supporting vasculature. Identifying adipocyte progenitors and the mechanism of adipose tissue expansion is crucial for the development of new strategies to combat obesity and its complications. Though important progress has been made towards understanding the developmental origin of adipocytes, the identities of adipocyte progenitors are still not completely known. The main objective of this study is to determine whether endothelial cells of the adipose tissue can give rise to new adipocytes. Our results indicate that murine endothelial cells of adipose tissue are pluripotent and can potentially give rise to preadipocytes. Lineage tracing experiments using the VE-Cadherin-Cre transgenic mouse reveal localization of reporter genes in endothelial cells, preadipocytes and white and brown adipocytes. Moreover, capillary sprouts from human adipose tissue, which have predominantly endothelial cell characteristics, are found to express Zfp423, a preadipocyte determination factor. In response to PPARγ activation, endothelial characteristics of sprouting cells are progressively lost, and cells form structurally and biochemically defined adipocytes. Taken together, our data support an endothelial origin of a population of adipocytes. The ability of the vascular endothelium to give rise to adipocytes may explain how angiogenesis and adipogenesis can be temporally and spatially coordinated. Analysis of BAT and WAT revealed that adipose depots have distinct compositions of adipocyte progenitors. Of the CD45-CD29+Sca1+CD24+ progenitor population, only 17% and 52% express VE-Cadherin in WAT and BAT, respectively. Our data show that the number of these specific progenitors in BAT and WAT are highly variable and suggest that a considerable number of adipocytes progenitors may have a non-endothelial cell origin. Differences in composition and types of adipocyte progenitors may explain the differences in the adipocytes phenotypes that we observe in discrete depots. In brief, we find that the vascular endothelium gives rise to a population of brown and white fat cells, and that the number of endothelial-derived adipocyte progenitors residing in BAT and WAT is highly variable. These results expand our current understanding of adipose tissue growth, and, we hope, will accelerate the development of treatments for obesity-related complications.
445

Vliv obvyklé pokojové teploty na BMI, resp. prevalenci obezity vybraného vzorku populace / An influence of usual room temperature on BMI or obesity prevalence in a population sample

BEDNAŘÍKOVÁ, Renata January 2017 (has links)
The main aim of the diploma thesis is to determine if BMI (Body Mass Index) in humans is related to the indoor room temperature. Lower room temperature can lead to the activation of brown adipose tissue (BAT), thereby increasing energy expenditure. Because the thermal comfort is individual to some extent, the task is to determine whether there is a correlation between BMI and the frequency of perceived thermal discomfort. The research was attended by 202 respondents in the age range of 3 to 27. All were measured and weighed, and then the temperature habits were recorded through questionnaire. A group of students underwent more detailed data collection. For the evaluation of the data was used PCA (Principal Component Analysis) and regression analysis, for determining the influence of the room temperature, data were weighed by the coefficient of the thermal insulation during the night. The results showed that BMI, respectively the percentile BMI class of respondents in-creases with increasing average bedroom night temperature. Results are less clear for the age categories with no dependency between BMI and room temperature in the youngest age category, significant correlation in adolescent females and adult men, but not signifi-cant correlation in adolescent males and adult females. Evaluation of 87 responses from adolescent and adult respondents to the question regard-ing the frequency of subjective cold feeling showed that the more they felt the coldness in their dwellings, the lower was percentile BMI class and BMI in different age groups. Based on these results we can state that the room temperature during sleep is another sig-nificant factor influencing BMI and lowering the temperature in the homes could lead to the reduction of population obesity.
446

Efeito do exercício exaustivo sobre aspectos inflamatórios no músculo esquelético e tecido adiposo de ratos / Effect of exhaustive exercise on inflammatory aspects in skeletal muscle and adipose tissue of rats

Rosa Neto, José Cesar [UNIFESP] 28 April 2010 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:49:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-28 / Objetivo: Verificar o efeito inflamatório do exercício agudo exaustivo sobre diferentes depósitos de tecido adiposo branco (mesentérico e retroperitoneal), assim como, sobre músculos esqueléticos (sóleo: fibra muscular tipo I; EDL: fibra muscular tipo II). Métodos: os animais (ratos Wistars) foram submetidos a uma sessão exaustiva de exercício, após período de adaptação. Os depósitos de tecido adiposo branco, retroperitoneal e mesentérico, como, os músculos EDL e sóleo, foram retirados logo após o sacrifício e analisados para a expressão gênica (PCR-real time) e protéica (ELISA) da citocinas IL-6, IL-10, TNF-α, IL-2 e IL-4. O sacrifício foi realizado logo após a sessão de exercício, duas e seis horas após, e o grupo controle não foi submetido à sessão exaustiva de exercício. Por Western Blotting foi analisado o conteúdo de TLR-4, e sua via de sinalização TRAF6 e MYD88. Resultados: As citocinas IL-6, IL-10 e TNF-α foram encontradas elevadas em todos os tecidos e grupos dos ratos exercitados. No entanto, a razão IL-10/TNF-α foi maior no músculo e encontrou-se diminuída no tecido adiposo. O TLR-4, assim como sua via (TRAF6 e MYD88), foi aumentada nos depósitos de tecido adiposo branco de ratos submetidos ao exercício exaustivo, sem alteração no EDL e sóleo. Já as citocinas IL-2 e IL-4 tiveram suas concentrações alteradas no sóleo e EDL, mas não foram moduladas no tecido adiposo pelo protocolo de exercício exaustivo. Conclusão: O exercício exaustivo apresentou um aumento da resposta antiinflamatória no músculo esquelético, pelo aumento da razão IL-10/TNF-α. Já o tecido adiposo observado (mesentérico e retroperitoneal) apresentou um aumento da resposta inflamatória, evidenciada pela diminuição da razão IL-10/TNF-α e pelo aumento da expressão protéica do TLR-4. Além disso, a IL-4 foi aumentada 6 horas após o protocolo de exercício no EDL, concomitante com o aumento do MyoD. Esse aumento pode levar a um aumento da hiperplasia muscular. / Aim: to verify the inflammatory effects of exhaustive exercise on adipose tissue (mesenteric and retroperitoneal), and skeletal muscle (sóleus: fiber type I, EDL: Fyber type II). Methods: Wistar rats were randomly assigned to four groups: group control and group exercised until exhaustion, these rats were sacrificed in three different times, after the exhaustion, two hours after and six hours after exhaustive exercise. Cytokines IL-2, IL-4, TNF-α, IL-6 and IL-10 were analyzed by mRNA (PCR Real Time) and protein (ELISA) expression. TLR-4 and your inflammatory via (TRAF6, MYD88), were analyzed by Western Blotting. Results: IL-6, IL-10 and TNF-α were elevated in all tissues and groups compared with control group. However, IL-10/TNF-α ratio was higher in skeletal muscle, and opposite response was found in adipose tissue. TLR-4 and your via was elevated in adipose tissue, but not altered in skeletal muscle after exhaustive exercise. The concentrations of IL-2 and IL-4 were altered in skeletal muscle, but were not modulated in adipose tissue, after exercise protocol. Conclusion: exhaustive exercise showed one increased in anti-inflammatory response in skeletal muscle, by increased of IL-10/TNF-α ratio. On the other hand, adipose tissue showed increased in inflammatory response, evidenced by decreased in IL-10/TNF-α ratio and increased in TLR-4 content. Moreover, the IL-4 was increased in EDL, concomitant with raised in Myod. This results could showed one increased in hyperplasia in skeletal muscle. / TEDE / BV UNIFESP: Teses e dissertações
447

Papel anti-inflamatório da adiponectina e da interleucina-10 em modelos clínico e experimental de obesidade / Role anti-inflammatory of adiponectin and interleukin-10 in obesity model clinical and experimental

Lira, Fábio Santos de [UNIFESP] 02 December 2012 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:50:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-02 / Objetivo: Verificar os efeitos anti-inflamatórios da adiponectina e da interleucina 10 em modelos clínico e experimental de obesidade. O estudo foi dividido em duas etapas: clínico com adolescentes obesos submetidos à terapia de redução de peso interdisciplinar por 1 ano; e experimental in vitro, com adipócitos 3T3-L1. No estudo clínico, foram sujeitos do estudo 18 adolescentes (7 meninos e 11 meninas, idade 15 1,7 anos, índice de massa corporal (IMC) acima do Percentil 95. Os adolescentes participaram do programa de terapia interdisciplinar por 1 ano. Parâmetros antropométricos e bioquímicos séricos foram analisados antes e após a terapia. Nesta etapa do projeto observamos que, a redução da gordura visceral, assim como das adipocinas pró-inflamatórias no soro foram acompanhadas pelo aumento da adiponectina e da interleucina 10. Outro fator analisado foi a concentração sérica de endotoxina e resistência à ação da insulina. Pudemos observar que a melhora do quadro da resistência à ação da insulina foi acompanhada pela redução da endotoxina sérica após a terapia interdisciplinar. A redução da endotoxina correlacionou-se com aumento da adiponectina sérica. Tais alterações sugeriram que essas adipocinas anti-inflamatórias (adiponectina e interleucina 10) podem estar envolvidas nos processos anti-inflamatórios induzidos pelo programa de terapia interdisciplinar, e com a melhora do quadro inflamatório destes adolescentes obesos. No estudo in vitro, analisamos os mecanismos intracelulares da resposta inflamatória em células adiposas 3T3-L1, estimuladas com lipopolissacarídeo (LPS), na ausência ou presença da adiponectina e interleucina 10, isoladas e associadas, a fim de elucidar os efeitos anti-inflamatórios da adiponectina e interleucina 10. Para tanto, avaliamos a secreção de IL-6 e a cascata de sinalização dos Toll Like Receptors (TLR-2, TLR-4, MyD88 e TRAF6), assim como o Fator Nuclear kappa B e sua ligação com DNA. Observamos que, adipócitos 3T3-L1 tratados por 24h mostraram elevada concentração de IL-6 no meio de cultura, assim como, aumento da cascata de sinalização da via do NF-κB e da expressão protéica do IL-6R, TLR-4, MyD88, TRAF6. A adiponectina e IL-10 inibiram o aumento na concentração de IL-6, bem como a ligação do NF-κB com DNA. Tomados em conjunto, nossos resultados tanto clínico quanto experimental fornecem evidência de que a adiponectina e IL-10 têm importante papel na resposta anti-inflamatória, inibindo a via de sinalização do NF-κB e consequentemente reduzindo as adipocinas pró-inflamatórias. Corroboram com a ideia de que tais adipocinas podem ser excelentes estratégias para o tratamento do estado inflamatório na obesidade. / Objective: The purpose of the present study was to assess the dietary fat intake, glucose, insulin, Homeostasis model assessment for insulin resistance HOMA, and endotoxin level and correlate them with adipokine serum concentrations in obese adolescents who had been admitted to long-term interdisciplinary weight-loss therapy. Design: The present study was a longitudinal clinical intervention of interdisciplinary therapy. Adolescents (n=18, aged 15-19 y) with a body mass index > 95th percentile were admitted and evaluated at baseline and again after 1 year of interdisciplinary therapy. We collected blood samples, and IL-6, adiponectin, and endotoxin concentrations were measured by ELISA. Food intake was measured using 3-day diet records. In addition, we assessed glucose and insulin levels as well as the homeostasis model assessment for insulin resistance (HOMAIR). Results: The most important finding from the present investigation was that the long-term interdisciplinary lifestyle therapy decreased dietary fat intake and endotoxin levels and improved HOMA-IR. We observed positive correlations between dietary fat intake and endotoxin levels, insulin levels, and the HOMA-IR (p<0.05). In addition, endotoxin levels showed positive correlations with IL-6 levels, insulin levels and the HOMA-IR (p<0.05). Interestingly, we observed a negative correlation between serum adiponectin and both dietary fat intake and endotoxin levels (p<0.05). Conclusions: The present results indicate that reduced dietary fat intake and endotoxin level was highly correlated with a decreased pro-inflammatory state and an improvement in HOMA-IR. In addition, this benefits effect may be associated with an increased adiponectin level, which suggests that the interdisciplinary therapy was effective in decreasing inflammatory markers. / TEDE / BV UNIFESP: Teses e dissertações
448

Validação da ultra-sonografia em relação à Tomografia computadorizada na determinação de gordura abdominal em pacientes coronariopatas

Oliveira, Eloína Nunes January 2002 (has links)
Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-11-27T19:08:40Z No. of bitstreams: 1 Eloina Nunes de Oliveira Validacao da ultra... 2002.pdf: 56743053 bytes, checksum: 8de974eee276ef14038c01e971d6e751 (MD5) / Made available in DSpace on 2012-11-27T19:08:40Z (GMT). No. of bitstreams: 1 Eloina Nunes de Oliveira Validacao da ultra... 2002.pdf: 56743053 bytes, checksum: 8de974eee276ef14038c01e971d6e751 (MD5) Previous issue date: 2002 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / Como fator de risco cardiovascular, a distribuição de gordura corporal é provavelmente mais significante do que o aumento de peso por si só. A quantificação de adiposidade visceral é de grande valor, pois esse tecido tem um papel importante em agregar os fatores de risco metabólicos. 0 padrão ouro para avaliação quantitativa da adiposidade visceral é a Tomografia Computadorizada (TC). 0 uso dessa técnica na pesquisa de gordura visceral é limitado devido ao equipamento necessário, alto custo e exposição à radiação ionizante. Em estudos clínicos e epidemiológicos a medida da cintura é estimativa mais freqüentemente usada para gordura abdominal visceral. Apesar dessa medida mostrar uma boa correlação com a medida de gordura abdominal visceral pela TC, ela é menos precisa e fortemente associada com índice de massa corpórea. A ultra-sonografia (LIS) tem sido proposta como uma técnica não invasiva, de baixo custo, para avaliação de gordura abdominal visceral. Objetivos: Validação do uso da ultra-sonografia na determinação de gordura abdominal em pacientes coronariopatas. Material e Métodos: Neste estudo observacional foram determinadas as espessuras abdominais subcutâneas e viscerais através da ultra-sonografia e áreas abdominais subcutâneas e viscerais pela TC, em uma população de coronariopatas e dislipidêmicos, constituída de 28,3% de mulheres e 71,1% de homens, idade média de 56,8 anos (32-81 anos), encaminhada pelo ambulatório de cardiopatia isquémica e dislipidemia (ACID) do Hospital Universitário Professor Edgar Santos (HUPES). Todos os pacientes foram submetidos a exame clínico, medidas antropométricas, US e TC. Resultados: A espessura abdominal visceral, medida pela US, mostrou correlação positiva significativa com área abdominal visceral pela TC (r = 0,73; p < 0,0001). Para a predição da área visceral pela TC foi realizada análise de regressão múltipla sendo que as variáveis de maior correlação foram compostas pelas medidas de espessura abdominal visceral, a medida da cintura e idade (r^ = 0,69; p < 0,001). Conclusões: Em coronariopatas e dislipidêmicos a US mostrou-se método válido na determinação de gordura abdominal visceral. É possível determinar através da US a área de gordura abdominal visceral com grau de determinação de quase 70%. / Fat distribution is probably more significant tlian weight increase per se as a cardiovascular risk factor. Because visceral adiposity has a central role in the cluster of metabolic risk factors, its quantification is of extreme importance. Currently, Computed Tomography (CT) is the gold standard for quantitative assessment of intra-abdominal adipose tissue. This technique is obviously limited because of high cost and radiation exposure. In clinical and epidemiological studies the waist circumference is the most often used estimation of intra-abdominal adipose tissue. Although, this measure shows a good correlation with CT-measured intra-abdominal adipose tissue, it is less precise and less strongly associated with body mass index. Ultrasonography has been proposed as a noninvasive technique to accurately measure intra- abdominal adipose tissue. Objective: Validity of use of ultrasonography for 11 the determination of abdominal adipose tissue in patient with coronary heart disease. Material and Methods: This observational study was carried out among 60 patients with coronary heart disease and dyslipidemia. Subcutaneous and intra-abdominal adipose tissue thickness were measured by ultrasonography, and subcutaneous and intra-abdominal adipose tissue areas by CT. All patients were submitted to clinical examination, anthropometry, ultrasonography and CT evaluation. Results: The mean age of the study group was of 56,8 ± 10,2, the sex distribution was of 28,3% women and 71,1% men. The thickness of intra-abdominal adipose tissue measured by ultrasonography showed significant positive correlation with intra-abdominal adipose tissue area by CT (r = 0,73; p <0,000). Multiple regression analysis was applied for the prediction of intra-abdominal area by CT. The variables of better correlation were composed of the measures of intra-abdominal adipose tissue thickness, the measure of the waist circumference and age (r^ = 0,69; p <0,001). The area under the Receiver Operating Characteristic Curve (ROC) was 0,81 (IC95% de 0,68-0,95). Conclusions: In patients with coronary heart disease, ultrasonography is a good method to diagnose and to determine intra-abdominal adipose tissue. It is possible to determine through ultrasonography and anthropometry, the area of intra-abdominal tissue with a degree of precision of almost 70%.
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Tissu adipeux et résistance tumorale aux thérapies ciblées / Adipose tissue and tumor resistance to targeted therapies

Geneste, Aline 06 July 2018 (has links)
Les thérapies ciblées telles que les inhibiteurs de la tyrosine kinase ont permis d'améliorer le traitement du cancer du sein en ciblant HER2. Cependant, il a été observé que le lapatinib était moins efficace chez les patients obèses ou en surpoids que chez les patients de poids normal.Nous avons d'abord reproduit l'effet de résistance des cellules de cancer du sein au lapatinib en présence de tissu adipeux tel qu’il a été observé pour d’autres thérapies. Les cellules tumorales qui surexpriment HER2 étaient partiellement résistantes au lapatinib mais également à d'autres inhibiteurs de la tyrosine kinase lorsqu'elles étaient en contact avec le milieu conditionné d’adipocytes. En implantant du tissu adipeux humain et des tumeurs humaines chez la souris, nous avons pu étudier la résistance du cancer du sein au lapatinib in vivo.Pour comprendre le mécanisme de cette résistance, nous avons exposé les adipocytes à plusieurs modulateurs du métabolisme. La cytotoxicité cellulaire induite par le lapatinib était plus faible pour les cellules tumorales exposées à un milieu conditionné d'adipocytes préalablement incubés avec les alpha-bloquants qu'à un milieu conditionné à partir d'adipocytes seuls. De la même manière, cette toxicité était inférieure pour les agonistes des récepteurs alpha adrénergiques, pour les bêtabloquants et pour les inhibiteurs de lipolyse. Au contraire, la cytotoxicité a été augmentée pour les cellules tumorales en contact avec le milieu conditionné d’adipocytes exposés aux agonistes du récepteur bêta-adrénergiques. Au niveau des cellules cancéreuses, l'arrêt du cycle cellulaire induit par le lapatinib était réduit pour les cellules tumorales exposées au milieu conditionné d’adipocytes en ce qui concerne le pourcentage de cellules dans la phase G0/G1. Ceci s’est vérifié en étudiant l'expression des gènes codant pour plusieurs protéines impliquées dans la progression du cycle cellulaire / Targeted therapies as tyrosine kinase inhibitors permitted an improvement of breast cancer therapies by targeting HER2. However, resistance has been observed in obèse patients for lapatinib treatment.We reproduced the effect of resistance of breast cancer cells to laaptinib in presence of adipose tissue as observed for other therapies. Tumor cells overexpressing HER2 was partly resistant to lapatinib but also for other tyrosine kinase inhibitors when in contact with adipocyte-conditioned medium. By impnating human adipose tissue nad human tumors in mice, we were able to study rhe resistance of breast tumor cells in vivo.In order to elucidate the mechanism of such resistance, we exposed the adipocytes to several metabolism modulators. The lapatinib-induced cell cytotoxicity was lower for the tumor cells exposed to the conditioned medium from adipocytes earlier exposed to alpha blockers than to the conditioned medium from adipocytes alone. In the same manner, the toxicity was lower for the agonists of alpha-adrenergic receptors , for beta-blockers and for the lipolysis inhibitors. At the opposite, the cytotoxicity was enhanced for tumor cells in contact with the conditioned medium of adipocytes exposed to the agonists of beta adrenergic receptors.At the tumor cell level, the laaptinib-induced cell cycle arrest was reduced for the tumor cells exposed to the conditioned medium regarding the G0/G1 phase. That was verified by the study of the expression of genes involved in the cell cycle progression
450

Efeitos do treinamento resistido em ratos alimentados com dieta hiperlipídica / Effects of resistance training in rat feed with hyperlipidic diet

Richard Diego Leite 18 February 2013 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O consumo excessivo de gorduras tem sido implicado na gênese da obesidade e de diversas comorbidades relacionadas a esta doença. O objetivo do presente estudo foi avaliar o efeito do treinamento resistido em ratos alimentados com dieta hiperlipídica nas seguintes variáveis: composição corporal, adiposidade, área de adipócitos, expressão do fator de crescimento do endotélio vascular (VEGF) e dos receptores ativados por proliferadores de peroxissomo tipo gama (PPAR-&#947;) no tecido adiposo retroperitoneal, níveis pressóricos e atividade da metaloproteinase-2 (MMP-2) no ventrículo esquerdo. Foram avaliados 32 ratos machos Wistar divididos em quatro grupos experimentais (n=8/cada) de acordo com o tipo de dieta e o treinamento: sedentário (SED; dieta padrão), sedentário obeso [SED-OB; dieta hiperlipídica (30% de gordura)], treinamento resistido (TR; dieta padrão) e treinamento resistido obeso (TR-OB; dieta hiperlipídica). Após o desmame (dia 21), os animais foram submetidos à dieta experimental durante 24 semanas. Doze semanas após início da dieta, os grupos TR e TR-OB iniciaram o período de 12 semanas de treinamento resistido. Este era composto por escaladas em uma escada vertical de 1.1 metros com pesos atados a cauda num total de três sessões de treinamento por semana (Segundas, Quartas e Sextas-feiras) com 4 a 9 escaladas/sessão e 8 a 12 movimentos dinâmicos a cada subida. O treinamento resistido induziu reduções significativas na massa corporal, na massa gorda, no percentual de gordura, na área de adipócitos e nos níveis pressóricos e ainda promoveu aumento de massa magra e na expressão de VEGF e PPAR-&#947; em ambos os grupos treinados. Além disso, foi observada uma maior atividade da MMP-2 no ventrículo esquerdo nos grupos treinados (TR e TR-OB). Nossos achados demonstram que o treinamento resistido foi capaz de promover mudanças positivas na composição corporal, na atividade da MMP-2 no ventrículo esquerdo, nos níveis pressóricos e em mediadores enzimáticos do tecido adiposo retroperitoneal sugerindo que esta modalidade de exercício pode ser uma ferramenta útil para prevenir as alterações induzidos pelo consumo de uma dieta hiperlipídica. / The purpose of the present study was to evaluate the effect of resistance training on body composition, adiposity, adipocyte area, vascular endothelium growth factor (VEGF) and peroxisome proliferator-activated receptor-gamma (PPAR-&#947;) in adipose tissue, systolic and diastolic blood pressures (BP), and activity of muscle MMP-2 in left ventricle. We evaluated 32 Wistar rats divided into four experimental groups (n=8/each) according to diet and exercise status: sedentary (SED; standard diet), sedentary obese [SED-OB; hiperlipidic diet (30% of fat)], resistance training (RT; standard diet) and resistance training RT obese (RT-OB; hiperlipidic diet). After weaning (day 21), animals were subjected to the experimental diet according to their groups during 24 weeks. A 12-week resistance-training period was used, during which the animals climbed a 1.1-m vertical ladder with weights attached to their tails. The sessions were performed three times/week (Mondays, Wednesdays and Fridays), with 49 climbs/session and 812 dynamic movements/climb with two rest minutes. The RT promoted significantly reductions of body and fat masses, fat percentage, adipocytes area and systolic and diastolic BPs, associated with higher expression of VEGF and PPAR-&#947; in retroperitoneal adipose tissue and higher fat free mass in both trained groups. Furthermore, it was observed higher muscle MMP-2 activity of the left ventricle in trained animals. This study demonstrated that, resistance training induced positive changes in body composition, MMP-2 activity in left ventricle, systolic and diastolic BPs and adipose tissue metabolism, suggesting that it can be a useful tool to prevent the physiopathological changes induced by high-fat diet consumption.

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