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1.
J Gerontol A Biol Sci Med Sci ; 70(2): 163-73, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24550352

RESUMO

Aging is usually accompanied by a significant reduction in muscle mass and force. To determine the relative contribution of inactivity and aging per se to this decay, we compared muscle function and structure in (a) male participants belonging to a group of well-trained seniors (average of 70 years) who exercised regularly in their previous 30 years and (b) age-matched healthy sedentary seniors with (c) active young men (average of 27 years). The results collected show that relative to their sedentary cohorts, muscle from senior sportsmen have: (a) greater maximal isometric force and function, (b) better preserved fiber morphology and ultrastructure of intracellular organelles involved in Ca(2+) handling and ATP production, (c) preserved muscle fibers size resulting from fiber rescue by reinnervation, and (d) lowered expression of genes related to autophagy and reactive oxygen species detoxification. All together, our results indicate that: (a) skeletal muscle of senior sportsmen is actually more similar to that of adults than to that of age-matched sedentaries and (b) signaling pathways controlling muscle mass and metabolism are differently modulated in senior sportsmen to guarantee maintenance of skeletal muscle structure, function, bioenergetic characteristics, and phenotype. Thus, regular physical activity is a good strategy to attenuate age-related general decay of muscle structure and function (ClinicalTrials.gov: NCT01679977).


Assuntos
Envelhecimento/fisiologia , Exercício Físico/fisiologia , Fibras Musculares Esqueléticas/ultraestrutura , Músculo Esquelético/fisiologia , Adulto , Idoso , Biópsia por Agulha , Cálcio/metabolismo , Teste de Esforço , Humanos , Fator de Crescimento Insulin-Like I/genética , Contração Isométrica/fisiologia , Masculino , Proteínas de Membrana/metabolismo , MicroRNAs/genética , Microscopia Eletrônica de Transmissão , Mitocôndrias Musculares/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Atrofia Muscular/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Isoformas de Proteínas/genética , Proteínas Proto-Oncogênicas/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Comportamento Sedentário , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Fatores de Transcrição/metabolismo , Regulação para Cima/fisiologia , Fator de Transcrição YY1/metabolismo , Adulto Jovem
2.
Neurol Res ; 32(1): 26-31, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20092692

RESUMO

OBJECTIVE: To examine the effects of 8 weeks of vibration training at different frequencies (1 and 15 Hz) on maximal isometric torque and force development in senior sportsmen, and of 1 year of heavy-resistance and vibration trainings on muscle fibers. METHODS: Seven healthy senior sportsmen (mean age: 69.0 +/- 5.4 years) performed an 8 weeks of strength training of knee extensors. Vibrations were applied vertically to the axis of movement during training. One leg of each subject was trained at a frequency of 1 Hz, while the other leg was trained at 15 Hz. Measures of isometric peak torque (at knee-angles of 60, 90 and 120 degrees ) and force development were recorded before and after training. Four sportsmen continued a year-long heavy-resistance training adding every second week a session of vibration training. After training, muscle biopsies were harvested from their quadriceps muscles and used for structural analyses. Morphometry of muscle fibers was performed by light microscopy. Immunohistochemistry using anti-MHCemb and anti-N-CAM antibodies was performed to measure potential muscle damage. Data from muscle morphometry were compared to that of a series of vastus lateralis biopsies harvested from 12 young sportsmen and four healthy elderly. RESULTS: Our results showed a significant increase in isometric peak torque at both 1 and 15 Hz vibration frequency in all three measured angles of the knee. There was no significant difference between the two frequencies, but we could find a higher increase in percentage of maximum power after the 1 Hz training. The results of force development showed a slight increase at the 1 Hz training in measured time frames from 0 to 50 and 200 ms, without statistical significance. A trend to significance was found at the 1 Hz training at the time window up to 200 ms. The 15 Hz training showed no significant changes of force development. Muscle biopsies show that the muscles of these well trained senior sportsmen contain muscle fibers which are 35% larger than those of sedentary elderly and, unexpectedly, 10% larger than those of young sportsmen. Despite 1 year of heavy resistance and vibration training, no evidence of muscle damage or denervation/reinnervation could be observed by light microscopy analyses, ATPase histochemistry and immunohistochemistry using anti-N-CAM or anti-MHC-emb antibodies. DISCUSSION: Integration of vibration to conventional strength training in elderly sportsmen induces similar improvement of isometric peak torque and force development independently from the vibration frequency after 8 weeks of training, and long-term results in the surprising evidence of hypertrophic muscle fibers larger than those of young active sportsmen. The observation that the vibration training with low frequency is safe opens the possibility to test these rehabilitation procedures in sedentary elderly.


Assuntos
Fibras Musculares Esqueléticas/fisiologia , Força Muscular/fisiologia , Treinamento Resistido/métodos , Torque , Vibração/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Atletas , Humanos , Imuno-Histoquímica , Joelho/fisiologia , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Fatores de Tempo , Adulto Jovem
3.
Eur J Cancer Care (Engl) ; 17(5): 454-62, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18637115

RESUMO

The serum cytokine levels (in particular interleukine-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha)) of 61 advanced stage cancer patients receiving palliative chemotherapy as outpatients were determined with quantikine immunoassays. The values were correlated with body mass index (BMI), weight loss and appetite. Furthermore cytokine levels of patients who have died within one year were compared with those of patients who have survived more than a year. Serum levels of IL-6 (median: 1.93 pg/ml, range: 0.32-42.87) and of TNF-alpha (median: 2.55 pg/ml, range: 1.03-34.06) did not correlate with BMI, weight loss and appetite. Serum IL-6 levels of patients with survival time less than one year were significantly higher than the levels of patients who survived more than one year, no significant differences in TNF-alpha serum levels were evident. The data of this observation are consistent with current literature. Due to changes in serum levels of proinflammatory cytokines in response to chemotherapy and additional therapy, it is unlikely that IL-6 and TNF-alpha can be used as independent indicators for weight loss and appetite. Nevertheless, high serum levels of IL-6 correlate with short-time mortality.


Assuntos
Antineoplásicos/uso terapêutico , Índice de Massa Corporal , Interleucina-6/sangue , Neoplasias/tratamento farmacológico , Fator de Necrose Tumoral alfa/sangue , Adulto , Idoso , Assistência Ambulatorial/métodos , Apetite , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/mortalidade , Cuidados Paliativos , Taxa de Sobrevida , Redução de Peso
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