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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.
11

Prevalência de equinos quarto de milha portadores das mutações causadoras da miopatia por acúmulo de polissacarídeo tipo 1, paralisia periódica hipercalêmica e hipertermia maligna no Brasil /

Delfiol, Diego José Zanzarini. January 2014 (has links)
Orientador: Alexandre Secorun Borges / Coorientador: José Paes de Oliveira Filho / Banca: Rogério Martins amorim / Banca: Carlos Alberto Hussni / Banca: Luiz Cláudio Nogueira Mendes / Banca: Paulo Henrique Jorge da Cunha / Resumo: Entre as principais enfermidades genéticas identificadas nos equinos da raça Quarto de Milha (QM) estão a miopatia por acúmulo de polissacarídeo 1 (PSSM1), a paralisia periódica hipercalêmica (HYPP) e a hipertermia maligna (HM). No Brasil o teste molecular para a PSSM1 e para HM não está disponível e tampouco se conhece sobre a prevalência destas enfermidades, enquanto que, para HYPP apesar do teste estar disponível no país, informações sobre sua prevalência são escassos. O objetivo deste trabalho foi padronizar o teste para PSSM1, HYPP e HM e estudar a prevalência destas enfermidades em cavalos da raça QM no Brasil. Foram utilizados DNA sanguíneo de 741 cavalos. O teste genético para as três enfermidades foi padronizado e as amostras sequenciadas para identificação da mutação no gene GYS1 responsável pela PSSM1, no gene SCN4A responsável pela HYPP e no gene RYR1 responsável pela HM. A prevalência da PSSM1 foi de 6,7%, da HYPP de 4,2% e não foram encontrados animais com a mutação responsável pela HM. Os resultados alertam para a importância da PSSM1 e da HYPP nos cavalos QM no Brasil. A padronização dos testes será útil para o diagnóstico da PSSM1 e da HM. Identificar os animais positivos para PSSM1, HYPP e HM irá auxiliar na escolha dos acasalamentos e será importante para minimizar a ocorrência destas enfermidades / Abstract: Type 1 polysaccharide storage myopathy (PSSM1), hyperkalemic periodic paralysis (HYPP) and malignant hyperthermia (MH) are considered major genetic diseases identified in Quarter Horses (QH). In Brazil, the molecular test for PSSM1 and MH is not available and the prevalence of both diseases is not known. Regarding HYPP, information about the disease prevalence is limited, although a molecular test is available in the country. The aim of this study was to standardize a molecular test for PSSM1, HYPP and MH, as well as to evaluate the diseases' prevalence in Brazilian QM. Blood DNA from 741 horses were used and genetic tests for the three diseases were standardized. Samples were sequenced to identify the mutation on GYS1 gene, responsible for the PSSM; on SCN4A gene, responsible for HYPP; and on RYR1 gene, responsible for MH. The prevalence obtained was 6.7% for PSSM1, 4.2% for HYPP and no positive results were found for MH. The results indicate the importance of PSSM1 and HYPP in QM in Brazil. Tests standardization would be useful for the diagnosis of PSSM1 and MH. The identification of positive animals for PSSM1, HYPP and MH would assist on the mating selections and thus reduce the occurrence of these diseases / Doutor
12

Proteomic study of the effects of palmitic acid on skeletal muscle cell and its relation with mitochondrial function. / CUHK electronic theses & dissertations collection

January 2012 (has links)
2 型糖尿病(T2D)的發展歷史悠久,但導致T2D 患者胰島素抵抗的確切病理還沒有完全理解。骨骼肌佔大多數(70-80%)的胰島素引導的葡萄糖的吸收,所以它一直是胰島素抵抗的研究焦點。許多 T2D 患者的骨骼組織顯示線粒體功能障礙,但線粒體功能障礙和胰島素抵抗之間的關係尚不清楚還在辯論中。在這個項目中,這種關係是通過研究游離脂肪酸(FFA)( 24 小時處理)對 C2C12 小鼠骨骼肌細胞的效果來闡明。 / 免疫印記法顯示FFA 誘導胰島素抵抗,結合二維電泳和質譜分析的蛋白質組學研究發現FFA 有抑制糖酵解,增加β-氧化作用,沒有改變檸檬酸循環和抑製氧化磷酸化的作用。FFA 抑制電子傳遞鏈的幾個組成部分,揭示線粒體功能障礙,背後的原因可推測為FFA 增加令β-氧化作用增加,但沒有協調改變率檸檬酸循環,導致積累不完全β-氧化的中轉體,導致線粒體過載,最終導致胰島素抵抗。 / There is a long history of Type 2 diabetes (T2D) research development, but the exact pathology leading to insulin resistance of T2D is still not fully understood. T2D is frequently characterized by tissue insulin resistance and it is often associated with an elevated concentration of palmitic acid (PA, a major kind of dietary fatty acid) in serum. Due to this correlation, much of the effort in the field had been concentrated on the effect of PA in insulin action and glucose metabolism, and how elevated PA could possibly cause insulin resistance in specific tissues. / Skeletal muscle accounts for the majority (70-80%) of insulin-mediated glucose uptake, so it has been the focus of insulin resistance studies. Many T2D patients having elevated serum free fatty acid (FFA, where PA is a kind of FFA) also show mitochondrial dysfunction in their skeletal tissue, but the relationship between mitochondrial dysfunction and insulin resistance in skeletal muscle remains unclear and under debate. In this project, the three-party relationship was elucidated by studying the effect of 24hrs of incubation of palmitic acid (PA) on skeletal muscle using C2C12 mouse skeletal cells as model. / PA-treated C2C12 cells show reduction in insulin-stimulated Akt phosphorylation when compared with untreated C2C12 cells. Comparative proteomic study for both total proteins and mitochondrial proteins with 2D gel electrophoresis and mass spectrometry unveil, when compared with untreated cells, PA-treated C2C12 cells show down-regulation in enzymes involved in glycolysis(e.g. glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, fructose-bisphosphate aldose A), up-regulation in enzymes involved in beta-oxidation(e.g. 3-ketoacyl-CoA thiolase, 3-hydroxyacyl-CoA dehydrogenase), and down-regulation in proteins involved in oxidative phosphorylation(e.g. ATP synthase subunits, NADH-ubiquinone oxidoreductase 75kDa subunit, cytochrome b-c complex subunit 1). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Lam, Chor Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 69-78). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Thesis/Assessment Committee --- p.i / Declaration --- p.ii / Abstract (in English) --- p.iii / Abstract (in Chinese) --- p.v / Acknowledgments --- p.vi / Table of Contents --- p.vii / List of Abbreviations --- p.x / List of Figures --- p.xiii / List of Tables --- p.xiv / Chapter 1. --- Literature review --- p.1 / Chapter 1.1. --- Introduction to diabetes mellitus --- p.1 / Chapter 1.1.1. --- Definition and prevalence --- p.1 / Chapter 1.1.2. --- Diagnosis and classification --- p.2 / Chapter 1.1.3. --- Symptoms and complications --- p.4 / Chapter 1.1.4. --- Causes and risk factors --- p.5 / Chapter 1.1.5. --- Prevention and treatment --- p.6 / Chapter 1.2. --- The role of muscle tissue in pathophysiology of T2DM --- p.7 / Chapter 1.3. --- Insulin receptor substrate-1 and Fatty acids-induced insulin resistance --- p.15 / Chapter 1.4. --- Introduction of proteomics --- p.18 / Chapter 1.4.1. --- The application of proteomics in disease discovery --- p.18 / Chapter 1.4.2. --- Application of Proteomics --- p.19 / Chapter 1.4.3 --- Two-dimensional gel electrophoresis --- p.20 / Chapter 1.4.4 --- Organelles proteomics --- p.21 / Chapter 1.4.5. --- Mass spectrometry --- p.22 / Chapter 1.4.6 --- Application of proteomic technology in disease pathology --- p.24 / Chapter 1.4.7 --- Current challenges --- p.25 / Chapter 1.5 --- Objectives --- p.27 / Chapter 2 --- Materials and Methods --- p.28 / Chapter 2.1 --- Fatty acid preparation --- p.28 / Chapter 2.2 --- Cell culture --- p.28 / Chapter 2.2.1 --- Treatment of C2C12 myotubes with Palmitic acid --- p.28 / Chapter 2.2.2 --- MTT assay for viability measurement --- p.29 / Chapter 2.2.3 --- Determination of the IC₅₀ values --- p.31 / Chapter 2.3 --- Proteomic analysis of C2C12 cells with and without PA treatment --- p.32 / Chapter 2.3.1 --- Protein sample preparation from C2C12 skeletal muscle cells --- p.32 / Chapter 2.3.2 --- Protein quantitation --- p.33 / Chapter 2.3.3 --- 2D Gel electrophoresis --- p.34 / Chapter 2.3.4 --- Image analysis --- p.36 / Chapter 2.3.5 --- In gel digestion and MALDI-ToF MS --- p.37 / Chapter 2.4 --- Mitochondrial purification and protein extraction --- p.38 / Chapter 2.4.1 --- Ultracentrifugation method --- p.38 / Chapter 2.4.2 --- Mitochondrial Isolation Kit --- p.39 / Chapter 2.5 --- Western Immunoblotting --- p.40 / Chapter 2.5.1 --- Protein sample preparation --- p.40 / Chapter 2.5.2 --- SDS-PAGE --- p.40 / Chapter 2.5.3 --- Western blotting --- p.40 / Chapter 2.5.4 --- Membrane Blocking and Antibody Incubations --- p.41 / Chapter 2.5.5 --- Detection of Proteins --- p.42 / Chapter 3 --- Results --- p.43 / Chapter 3.1 --- Differentiation of C2C12 myoblast into myotubes --- p.43 / Chapter 3.2 --- The effect of Palmitic acid on C2C12 Proliferation --- p.44 / Chapter 3.3 --- Comparison of total protein profiles of palmitic acid-treated C2C12 myotubes with control myotubes --- p.45 / Chapter 3.4 --- Western blotting of Akt and Phospho-Akt in C2C12 cells treated with Palmitic acid after acute exposure to insulin --- p.50 / Chapter 3.5 --- Comparison of two mitochondria isolation methodsultracentrifugation and mitochondrial isolation kit --- p.51 / Chapter 3.5.1 --- Quantity of extracted mitochondrial protein --- p.51 / Chapter 3.5.2 --- Purity of extracted mitochondrial protein --- p.52 / Chapter 3.6 --- Comparison of mitochondrial protein profiles between palmitic acid-treated and control C2C12 myotubes --- p.53 / Chapter 3.7 --- Western blotting of insulin receptor substrate-1 and its serine phosphorylation --- p.58 / Chapter 4 --- Discussion --- p.59 / Chapter 4.1 --- Investigation of anti-proliferating effect of Palmitic acid on C2C12 using MTT assay --- p.59 / Chapter 4.2 --- Comparison of total protein profiles of palmitic C2C12 myotubes with control myotubes --- p.60 / Chapter 4.3 --- Western blotting of insulin receptor substrate-1and its serine phosphorylation --- p.62 / Chapter 4.4 --- Western blotting of Akt and Phospho-Akt in C2C12 cells treated with Palmitic acid after acute exposure to insulin --- p.63 / Chapter 4.5 --- Comparison of mitochondrial protein profiles between palmitic acid-treated and control C2C12 myotubes --- p.65 / Chapter 4.6 --- Problems faced and future prospect --- p.68 / Chapter 5 --- References --- p.69
13

The expression, regulation and effects of inducible nitric oxide synthase in hibernating myocardium

Warner, Anke Sigrid. January 2002 (has links) (PDF)
Amendments inserted at back. "May 2002" Includes bibliographical references (leaves 237-290) Experiments described in this thesis address the potential role of inducible nitric oxide synthase (iNOS) in hibernating myocardium. Specifically it was sought to establish a cellular model of hibernating myocardium and investigate the expression, regulation and effects of iNOS in this model. Experiments were performed using primary cultures of neonatal rat ventricular myocytes.
14

The expression, regulation and effects of inducible nitric oxide synthase in hibernating myocardium / Anke Sigrid Warner.

Warner, Anke Sigrid January 2002 (has links)
Amendments inserted at back. / "May 2002" / Includes bibliographical references (leaves 237-290) / xvii, 290 leaves : ill., plates (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Experiments described in this thesis address the potential role of inducible nitric oxide synthase (iNOS) in hibernating myocardium. Specifically it was sought to establish a cellular model of hibernating myocardium and investigate the expression, regulation and effects of iNOS in this model. Experiments were performed using primary cultures of neonatal rat ventricular myocytes. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 2002
15

Consequence of paraspinal muscle after posterior lumbar spinal fusion: the histology and electromyography findingsin a rabbit model

梁漢邦, Leung, Hon-bong. January 2003 (has links)
published_or_final_version / Medical Sciences / Master / Master of Medical Sciences
16

A therapeutic approach for the skeletal muscle a-actin based congenital myopathies

Ravenscroft, Gianina January 2009 (has links)
[Truncated abstract] Mutations in the skeletal muscle -actin gene (ACTA1) have been shown to be one cause of a broad group of muscle disorders all termed the congenital myopathies. Over 170 different mutations have now been identified across all 6 coding exons of ACTA1 in patients presenting with muscle weakness and any one or more of the following histopathological features: nemaline rods, intranuclear rods, fibre-type disproportion, excess of thin filaments and central cores. While the identification of the causative gene has been of great comfort for affected patients and their families, with pre-natal genetic testing becoming available, the ultimate aim is to develop a therapy for these disorders. Of the therapies currently being explored for the muscular dystrophies, up-regulation of an alternative gene seemed to be one of the most promising avenues for treatment of the ACTA1 diseases. Up-regulation of utrophin, the foetal homologue of dystrophin, has been shown to be a promising therapy for the treatment of Duchenne muscular dystrophy. The main aim of my research was to determine whether up-regulation of cardiac -actin, the predominant -actin expressed in foetal skeletal muscle and in the adult heart, could be used as a therapy for the ACTA1 diseases. A proof-of-concept experiment was performed whereby skeletal muscle -actin knock-out (KO) mice (all of which die by postnatal day 9) were crossed with transgenic mice over-expressing cardiac -actin (known as Coco mice) in postnatal skeletal muscle. ... While patients that are ACTA1 nulls have been identified in a number of mainly consanguineous populations, the majority of ACTA1 mutations result in dominant disease in which the mutant protein interferes with the function of the wild-type skeletal muscle -actin. Research described in this thesis also focuses on characterizing two transgenic mouse models of dominant ACTA1 disease at the ultra-structural, cellular and functional level; this is the first step towards a proof-of-concept experiment to determine whether cardiac -actin up-regulation can dilute out the pathogenesis of dominant ACTA1 disease. It has long been noted that patients with ACTA1 disease do not have ophthalmoplegia, even in the most-severely affected individuals. Protein analysis performed on extraocular muscle (EOM) biopsies obtained from humans, sheep and pigs showed that the EOMs co-express cardiac and skeletal muscle -actin, with cardiac -actin comprising 70 % of the striated -actin pool. Thus we propose that sparing of the EOMs in ACTA1 disease is at least in part due to cardiac -actin diluting out the pathogenesis associated with expression of the mutant skeletal muscle -actin. This finding provides further support for the hypothesis that dilution of mutant skeletal muscle -actin in dominant ACTA1 disease by up-regulation of cardiac -actin may be a viable therapy for this group of devastating muscle diseases. The research contained herein has advanced the understanding of the pathobiology of skeletal muscle -actin diseases and provides strong evidence in support of cardiac -actin up-regulation as a promising therapy for these diseases.
17

Prevalência de equinos quarto de milha portadores das mutações causadoras da miopatia por acúmulo de polissacarídeo tipo 1, paralisia periódica hipercalêmica e hipertermia maligna no Brasil / Prevalence of types 1 polysaccharide storage myopathy, hyperkalemic periodic paralysis and malignant hyerthemia in quarter horse carriers in Brazil, Botucatu

Delfiol, Diego José Zanzarini [UNESP] 18 August 2014 (has links) (PDF)
Made available in DSpace on 2015-05-14T16:53:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-18Bitstream added on 2015-05-14T16:58:54Z : No. of bitstreams: 1 000816187_20160901.pdf: 105662 bytes, checksum: 2e6093c10157b40df91450fe5fd49495 (MD5) Bitstreams deleted on 2016-09-01T14:08:37Z: 000816187_20160901.pdf,. Added 1 bitstream(s) on 2016-09-01T14:09:15Z : No. of bitstreams: 1 000816187.pdf: 420717 bytes, checksum: 22781a1de14c050b79f4d11a1314a1c2 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Entre as principais enfermidades genéticas identificadas nos equinos da raça Quarto de Milha (QM) estão a miopatia por acúmulo de polissacarídeo 1 (PSSM1), a paralisia periódica hipercalêmica (HYPP) e a hipertermia maligna (HM). No Brasil o teste molecular para a PSSM1 e para HM não está disponível e tampouco se conhece sobre a prevalência destas enfermidades, enquanto que, para HYPP apesar do teste estar disponível no país, informações sobre sua prevalência são escassos. O objetivo deste trabalho foi padronizar o teste para PSSM1, HYPP e HM e estudar a prevalência destas enfermidades em cavalos da raça QM no Brasil. Foram utilizados DNA sanguíneo de 741 cavalos. O teste genético para as três enfermidades foi padronizado e as amostras sequenciadas para identificação da mutação no gene GYS1 responsável pela PSSM1, no gene SCN4A responsável pela HYPP e no gene RYR1 responsável pela HM. A prevalência da PSSM1 foi de 6,7%, da HYPP de 4,2% e não foram encontrados animais com a mutação responsável pela HM. Os resultados alertam para a importância da PSSM1 e da HYPP nos cavalos QM no Brasil. A padronização dos testes será útil para o diagnóstico da PSSM1 e da HM. Identificar os animais positivos para PSSM1, HYPP e HM irá auxiliar na escolha dos acasalamentos e será importante para minimizar a ocorrência destas enfermidades / Type 1 polysaccharide storage myopathy (PSSM1), hyperkalemic periodic paralysis (HYPP) and malignant hyperthermia (MH) are considered major genetic diseases identified in Quarter Horses (QH). In Brazil, the molecular test for PSSM1 and MH is not available and the prevalence of both diseases is not known. Regarding HYPP, information about the disease prevalence is limited, although a molecular test is available in the country. The aim of this study was to standardize a molecular test for PSSM1, HYPP and MH, as well as to evaluate the diseases’ prevalence in Brazilian QM. Blood DNA from 741 horses were used and genetic tests for the three diseases were standardized. Samples were sequenced to identify the mutation on GYS1 gene, responsible for the PSSM; on SCN4A gene, responsible for HYPP; and on RYR1 gene, responsible for MH. The prevalence obtained was 6.7% for PSSM1, 4.2% for HYPP and no positive results were found for MH. The results indicate the importance of PSSM1 and HYPP in QM in Brazil. Tests standardization would be useful for the diagnosis of PSSM1 and MH. The identification of positive animals for PSSM1, HYPP and MH would assist on the mating selections and thus reduce the occurrence of these diseases
18

Efeitos do hormônio do crescimento sobre vias de sinalização intracelular na miopatia associada à insuficiência cardíaca de ratos

Lima, Aline Regina Ruiz [UNESP] 26 February 2014 (has links) (PDF)
Made available in DSpace on 2015-05-14T16:53:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-26Bitstream added on 2015-05-14T16:58:53Z : No. of bitstreams: 1 000822448.pdf: 1004633 bytes, checksum: a3fbfa348eb8eb648f0380932bdacae5 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A insuficiência cardíaca (IC) crônica é comumente associada a atrofia de músculos esqueléticos, cujos mecanismos responsáveis ainda não estão completamente esclarecidos. O hormônio do crescimento (GH) tem efeitos anabólicos. Entretanto, seus efeitos na preservação da massa muscular em doenças catabólicas ainda não são bem entendidos. O GH estimula o IGF-1 e ativa a via PI3K/Akt inibindo seus efetores atrogina-1 e MuRF-1. Além disso, pode modular a expressão dos fatores de regulação miogênica e das proteínas miostatina e folistatina e a função de células satélites. O objetivo deste estudo é avaliar os efeitos da administração do GH sobre o trofismo e vias de sinalização intracelular envolvidas no processo de atrofia de músculos esqueléticos periféricos de ratos com insuficiência cardíaca crônica induzida por estenose aórtica (EAo). Após detecção clínica de IC, o GH foi administrado por 14 dias (grupo EAo-GH). Os resultados foram comparados com aqueles de grupos Sham e EAo sem tratamento. Ecocardiograma foi realizado antes e após o tratamento. O trofismo foi analisado nos músculos esqueléticos sóleo e porção branca do gastrocnêmio. A expressão proteica foi avaliada por Western blot e a ativação de células satélites por imunofluorescência. Análise estatística: ANOVA e Tukey ou Kruskal-Wallis e Student-Newman-Keuls. Antes do tratamento, os grupos EAo apresentaram comportamento semelhante em relação às variáveis ecocardiográficas. O tratamento com GH atenuou a disfunção sistólica. A área seccional das fibras do gastrocnêmio não diferiu entre os grupos e a do sóleo foi menor nos grupos com estenose aórtica que no Sham. No gastrocnêmio, MRF4 e atrogina-1 foram aumentadas nos grupos EAo e EAo-GH. O tratamento com GH atenuou elevação da MyoD e aumentou a visualização das proteínas NCAM e isoforma neonatal da cadeia pesada de miosina. No sóleo, o GH ativou as proteínas ... / Although chronic heart failure is usually associated with skeletal muscle atrophy, physiopathological mechanisms involved in muscle mass loss are not completed established. Growth hormone (GH) has anabolic effects. However, its effects on skeletal muscle preservation during catabolic diseases are not well understood. GH stimulates IGF-1, which activates PI3K/Akt pathway to inhibit atrogin-1 and MuRF-1. GH can also modulate myogenic regulatory factors and myostatin and follistatin protein expression as well as satellite cells activation. In this study, we evaluated the effects of GH administration on trophicity and intracellular signaling pathways involved in the atrophy process in peripheral skeletal muscles of rats with aortic stenosis (AS)-induced heart failure. After heart failure detection, GH was administered for 14 days (AS-GH group). Results were compared with those from Sham and non-treatment AS groups. Transthoracic echocardiogram was performed before and after treatment. Trophicity was analyzed in soleus and white portion of gastrocnemius muscles. Protein expression was evaluated by Western blot and satellite cells activation by immunofluorescence. Statistical analyses: ANOVA and Tukey or Kruskal-Wallis and Student-Newman- Keuls. Before treatment, AS groups presented similar echocardiographic parameters. GH attenuated systolic dysfunction. Sectional fiber areas of gastrocnemius did not differ between groups; in soleus, they were lower in both AS groups than Sham. In gastrocnemius, MRF4 and atrogin-1 were higher in AS and AS-GH groups. GH treatment attenuated MyoD increase. Immunofluorescence showed that staining with anti-neural cell adhesion molecule (NCAM) and antineonatal myosin heavy chain isoform were statistically more intense in AS-GH than AS and Sham. In soleus, GH activated IGF-1 and PI3K proteins. NCAM immunofluorescence was increased in both AS groups. In conclusion, GH treatment attenuates left ... / FAPESP: 10/50084-5
19

Efeitos do hormônio do crescimento sobre vias de sinalização intracelular na miopatia associada à insuficiência cardíaca de ratos /

Lima, Aline Regina Ruiz. January 2014 (has links)
Orientador: Mariana Politi Okoshi / Banca: Paula Felippe Martinez / Banca: João Carlos / Banca: Fábio Seiva / Banca: Eros Antônio Almeida / Resumo: A insuficiência cardíaca (IC) crônica é comumente associada a atrofia de músculos esqueléticos, cujos mecanismos responsáveis ainda não estão completamente esclarecidos. O hormônio do crescimento (GH) tem efeitos anabólicos. Entretanto, seus efeitos na preservação da massa muscular em doenças catabólicas ainda não são bem entendidos. O GH estimula o IGF-1 e ativa a via PI3K/Akt inibindo seus efetores atrogina-1 e MuRF-1. Além disso, pode modular a expressão dos fatores de regulação miogênica e das proteínas miostatina e folistatina e a função de células satélites. O objetivo deste estudo é avaliar os efeitos da administração do GH sobre o trofismo e vias de sinalização intracelular envolvidas no processo de atrofia de músculos esqueléticos periféricos de ratos com insuficiência cardíaca crônica induzida por estenose aórtica (EAo). Após detecção clínica de IC, o GH foi administrado por 14 dias (grupo EAo-GH). Os resultados foram comparados com aqueles de grupos Sham e EAo sem tratamento. Ecocardiograma foi realizado antes e após o tratamento. O trofismo foi analisado nos músculos esqueléticos sóleo e porção branca do gastrocnêmio. A expressão proteica foi avaliada por Western blot e a ativação de células satélites por imunofluorescência. Análise estatística: ANOVA e Tukey ou Kruskal-Wallis e Student-Newman-Keuls. Antes do tratamento, os grupos EAo apresentaram comportamento semelhante em relação às variáveis ecocardiográficas. O tratamento com GH atenuou a disfunção sistólica. A área seccional das fibras do gastrocnêmio não diferiu entre os grupos e a do sóleo foi menor nos grupos com estenose aórtica que no Sham. No gastrocnêmio, MRF4 e atrogina-1 foram aumentadas nos grupos EAo e EAo-GH. O tratamento com GH atenuou elevação da MyoD e aumentou a visualização das proteínas NCAM e isoforma neonatal da cadeia pesada de miosina. No sóleo, o GH ativou as proteínas ... / Abstract: Although chronic heart failure is usually associated with skeletal muscle atrophy, physiopathological mechanisms involved in muscle mass loss are not completed established. Growth hormone (GH) has anabolic effects. However, its effects on skeletal muscle preservation during catabolic diseases are not well understood. GH stimulates IGF-1, which activates PI3K/Akt pathway to inhibit atrogin-1 and MuRF-1. GH can also modulate myogenic regulatory factors and myostatin and follistatin protein expression as well as satellite cells activation. In this study, we evaluated the effects of GH administration on trophicity and intracellular signaling pathways involved in the atrophy process in peripheral skeletal muscles of rats with aortic stenosis (AS)-induced heart failure. After heart failure detection, GH was administered for 14 days (AS-GH group). Results were compared with those from Sham and non-treatment AS groups. Transthoracic echocardiogram was performed before and after treatment. Trophicity was analyzed in soleus and white portion of gastrocnemius muscles. Protein expression was evaluated by Western blot and satellite cells activation by immunofluorescence. Statistical analyses: ANOVA and Tukey or Kruskal-Wallis and Student-Newman- Keuls. Before treatment, AS groups presented similar echocardiographic parameters. GH attenuated systolic dysfunction. Sectional fiber areas of gastrocnemius did not differ between groups; in soleus, they were lower in both AS groups than Sham. In gastrocnemius, MRF4 and atrogin-1 were higher in AS and AS-GH groups. GH treatment attenuated MyoD increase. Immunofluorescence showed that staining with anti-neural cell adhesion molecule (NCAM) and antineonatal myosin heavy chain isoform were statistically more intense in AS-GH than AS and Sham. In soleus, GH activated IGF-1 and PI3K proteins. NCAM immunofluorescence was increased in both AS groups. In conclusion, GH treatment attenuates left ... / Doutor
20

Effect of a non-steroidal, anti-inflammatory drug (Indocin) on selected parameters of muscular function following concentric and eccentric work

Vejarano, Maria Eugenia 14 November 2012 (has links)
Evidence from various studies indicates that eccentric contractions produce more post-exercise changes in muscular function than do concentric contractions. Delayed muscular soreness, the pain and tenderness present 1 or 2 days after exercise, is negatively correlated with muscular performance and occurs particularly after eccentric work. The action of an analgesic, anti-inflammatory drug (Indocin) on muscular soreness indicates it may be effective in accelerating recovery of muscle function after eccentric work. In the study reported herein the effects of Indocin on muscular performance, as evaluated on the Cybex II isokinetic dynamometer, following prolonged concentric and eccentric work, were evaluated in 48 subjects who were randomly assigned to one of four drug groups. Subjects performed a 30 minute step test during which one limb led the stepping movement throughout (concentric contractions) and the contralateral limb trailed throughout (eccentric contractions). The muscular performance parameters of peak torque (PT), torque acceleration energy (TAE) and average power (AVP), evaluated at slow and high velocities, and the range of motion (ROM) at the knee joint were assessed prior to the step test and at five intervals thereafter. A non-significant decrease in PT and TAE at the contraction speed of 60 deg/sec were present in the eccentric limbs, greater reductions evidenced in the placebo group. Non-significant changes occurred in the concentric limbs, Non-significant changes in ROM and in muscular function parameters evaluated at 250 deg/sec were observed. / Master of Science

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