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1.
Proc Natl Acad Sci U S A ; 108(10): 4135-40, 2011 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-21368114

RESUMO

A causal role for mitochondrial DNA (mtDNA) mutagenesis in mammalian aging is supported by recent studies demonstrating that the mtDNA mutator mouse, harboring a defect in the proofreading-exonuclease activity of mitochondrial polymerase gamma, exhibits accelerated aging phenotypes characteristic of human aging, systemic mitochondrial dysfunction, multisystem pathology, and reduced lifespan. Epidemiologic studies in humans have demonstrated that endurance training reduces the risk of chronic diseases and extends life expectancy. Whether endurance exercise can attenuate the cumulative systemic decline observed in aging remains elusive. Here we show that 5 mo of endurance exercise induced systemic mitochondrial biogenesis, prevented mtDNA depletion and mutations, increased mitochondrial oxidative capacity and respiratory chain assembly, restored mitochondrial morphology, and blunted pathological levels of apoptosis in multiple tissues of mtDNA mutator mice. These adaptations conferred complete phenotypic protection, reduced multisystem pathology, and prevented premature mortality in these mice. The systemic mitochondrial rejuvenation through endurance exercise promises to be an effective therapeutic approach to mitigating mitochondrial dysfunction in aging and related comorbidities.


Assuntos
Envelhecimento/fisiologia , DNA Mitocondrial/genética , Mitocôndrias/fisiologia , Condicionamento Físico Animal , Resistência Física , Mutação Puntual , Envelhecimento/genética , Animais , Apoptose , Dosagem de Genes , Camundongos , Camundongos Mutantes , Estresse Oxidativo
2.
Nutrients ; 15(10)2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37242292

RESUMO

OBJECTIVE: Metabolic Syndrome (MetS) affects hundreds of millions of individuals and constitutes a major cause of morbidity and mortality worldwide. Obesity is believed to be at the core of metabolic abnormalities associated with MetS, including dyslipidemia, insulin resistance, fatty liver disease and vascular dysfunction. Although previous studies demonstrate a diverse array of naturally occurring antioxidants that attenuate several manifestations of MetS, little is known about the (i) combined effect of these compounds on hepatic health and (ii) molecular mechanisms responsible for their effect. METHODS: We explored the impact of a metabolic enhancer (ME), consisting of 7 naturally occurring antioxidants and mitochondrial enhancing agents, on diet-induced obesity, hepatic steatosis and atherogenic serum profile in mice. RESULTS: Here we show that a diet-based ME supplementation and exercise have similar beneficial effects on adiposity and hepatic steatosis in mice. Mechanistically, ME reduced hepatic ER stress, fibrosis, apoptosis, and inflammation, thereby improving overall liver health. Furthermore, we demonstrated that ME improved HFD-induced pro-atherogenic serum profile in mice, similar to exercise. The protective effects of ME were reduced in proprotein convertase subtilisin/kexin 9 (PCSK9) knock out mice, suggesting that ME exerts it protective effect partly in a PCSK9-dependent manner. CONCLUSIONS: Our findings suggest that components of the ME have a positive, protective effect on obesity, hepatic steatosis and cardiovascular risk and that they show similar effects as exercise training.


Assuntos
Resistência à Insulina , Síndrome Metabólica , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Pró-Proteína Convertase 9/metabolismo , Antioxidantes/metabolismo , Dieta Hiperlipídica/efeitos adversos , Obesidade/metabolismo , Fígado/metabolismo , Síndrome Metabólica/etiologia , Síndrome Metabólica/prevenção & controle , Síndrome Metabólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/metabolismo , Camundongos Endogâmicos C57BL
3.
Muscle Nerve ; 46(1): 42-50, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22644795

RESUMO

INTRODUCTION: Structural evidence of exercise-induced muscle disruption has traditionally involved histological analysis of muscle tissue obtained by needle biopsy, however, there are multiple limitations with this technique. Recently, diffusion tensor magnetic resonance imaging (DT-MRI) has been successfully demonstrated to noninvasively assess skeletal muscle abnormalities induced by traumatic injury. METHODS: To determine the potential for DT-MRI to detect musculoskeletal changes after a bout of eccentric exercise, 10 healthy men performed 300 eccentric actions on an isokinetic dynamometer. DT-MRI measurements and muscle biopsies from the vastus lateralis were obtained before and 24 h post-exercise. RESULTS: Z-band streaming was higher 24 h post-exercise compared with baseline (P < 0.05). The histological indices of damage coincided with changes in DT-MRI parameters of fractional anisotropy (FA) and apparent diffusion coefficient; reflecting altered skeletal muscle geometry (P < 0.05). Z-band streaming quantified per fiber correlated with FA (r = -0.512; P < 0.05). CONCLUSIONS: DT-MRI can detect changes in human skeletal muscle structure following eccentric exercise.


Assuntos
Exercício Físico/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/patologia , Adulto , Imagem de Tensor de Difusão , Humanos , Masculino , Músculo Esquelético/lesões , Músculo Esquelético/fisiologia
5.
PLoS One ; 14(1): e0210863, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30682077

RESUMO

Biological aging is associated with progressive damage accumulation, loss of organ reserves, and systemic inflammation ('inflammaging'), which predispose for a wide spectrum of chronic diseases, including several types of cancer. In contrast, aerobic exercise training (AET) reduces inflammation, lowers all-cause mortality, and enhances both health and lifespan. In this study, we examined the benefits of early-onset, lifelong AET on predictors of health, inflammation, and cancer incidence in a naturally aging mouse model (C57BL/J6). Lifelong, voluntary wheel-running (O-AET; 26-month-old) prevented age-related declines in aerobic fitness and motor coordination vs. age-matched, sedentary controls (O-SED). AET also provided partial protection against sarcopenia, dynapenia, testicular atrophy, and overall organ pathology, hence augmenting the 'physiologic reserve' of lifelong runners. Systemic inflammation, as evidenced by a chronic elevation in 17 of 18 pro- and anti-inflammatory cytokines and chemokines (P < 0.05 O-SED vs. 2-month-old Y-CON), was potently mitigated by lifelong AET (P < 0.05 O-AET vs. O-SED), including master regulators of the cytokine cascade and cancer progression (IL-1ß, TNF-α, and IL-6). In addition, circulating SPARC, previously known to be upregulated in metabolic disease, was elevated in old, sedentary mice, but was normalized to young control levels in lifelong runners. Remarkably, malignant tumours were also completely absent in the O-AET group, whereas they were present in the brain (pituitary), liver, spleen, and intestines of sedentary mice. Collectively, our results indicate that early-onset, lifelong running dampens inflammaging, protects against multiple cancer types, and extends healthspan of naturally-aged mice.


Assuntos
Envelhecimento/patologia , Envelhecimento/fisiologia , Inflamação/prevenção & controle , Neoplasias Experimentais/prevenção & controle , Condicionamento Físico Animal/métodos , Animais , Citocinas/fisiologia , Exercício Físico/fisiologia , Feminino , Envelhecimento Saudável , Humanos , Longevidade/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Atividade Motora , Sarcopenia/prevenção & controle
6.
Pediatr Blood Cancer ; 51(2): 183-7, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18421708

RESUMO

BACKGROUND: Corticosteroids are an important component of the treatment of acute lymphoblastic leukemia (ALL), with known significantly negative effects on bone and muscle. Creatine monohydrate (CrM) supplementation may be an adjunctive therapeutic strategy to attenuate some of these adverse effects. PROCEDURE: Nine children with ALL in the maintenance phase of treatment on the Dana-Farber Cancer Institute (DFCI) protocol 2000-2001 were treated with CrM (0.1 g/kg/day) for two sequential periods of 16 weeks (16 weeks treat > 6 weeks wash-out > 16 weeks treat). A cohort of children (N = 50) who were receiving the same chemotherapy at the same time served as natural history controls. Measurements included height, weight, body mass index (BMI), and lumbar spine bone mineral density (LS-BMD), whole body bone mineral content (WB-BMC), fat-free mass (FFM), and percent body fat (%BF) using dual-energy X-ray absorptiometry. RESULTS: Despite the long course of corticosteroid treatment for ALL, children showed significant increases in height, LS-BMD, WB-BMC and FFM over approximately 38 weeks (P < 0.05) during the study. There was an increase in BMI over time, but children taking CrM had a reduction, while the natural history group showed an increase in % BF (P < 0.05 for interaction). CONCLUSIONS: Children with ALL treated with corticosteroids as part of a maintenance protocol of chemotherapy showed an increase in % BF that was attenuated by CrM supplementation.


Assuntos
Tecido Adiposo/metabolismo , Creatina/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Corticosteroides/efeitos adversos , Composição Corporal/efeitos dos fármacos , Criança , Pré-Escolar , Suplementos Nutricionais , Feminino , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Estudos Retrospectivos
7.
J Pediatr Hematol Oncol ; 30(7): 553-7, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18797206

RESUMO

SUMMARY: The development of a soft-tissue sarcoma is an infrequent but well-known long-term complication of radiotherapy. Malignant fibrous histiocytomas, extraskeletal osteosarcomas, fibrosarcomas, malignant peripheral nerve sheath tumors, and angiosarcomas are most frequently encountered. Radiation-associated synovial sarcomas are uncommon and exceedingly rare in pediatric patients. We report an unusual case of paraspinal synovial sarcoma presenting in an adolescent female 13 years after radiation therapy for her neuroblastoma.


Assuntos
Neoplasias Musculares/etiologia , Neoplasias Induzidas por Radiação/etiologia , Segunda Neoplasia Primária/etiologia , Neuroblastoma/radioterapia , Neoplasias Retroperitoneais/radioterapia , Sarcoma Sinovial/etiologia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Cromossomos Humanos Par 18/genética , Cromossomos Humanos Par 18/ultraestrutura , Cromossomos Humanos X/genética , Cromossomos Humanos X/ultraestrutura , Cisplatino/administração & dosagem , Terapia Combinada , Ciclofosfamida/administração & dosagem , Dacarbazina/administração & dosagem , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Humanos , Ifosfamida/administração & dosagem , Lactente , Vértebras Lombares , Mecloretamina/administração & dosagem , Neoplasias Musculares/tratamento farmacológico , Neoplasias Musculares/genética , Neoplasias Musculares/radioterapia , Neoplasias Induzidas por Radiação/tratamento farmacológico , Neoplasias Induzidas por Radiação/genética , Neoplasias Induzidas por Radiação/radioterapia , Segunda Neoplasia Primária/tratamento farmacológico , Segunda Neoplasia Primária/genética , Segunda Neoplasia Primária/radioterapia , Neuroblastoma/tratamento farmacológico , Proteínas de Fusão Oncogênica/genética , Indução de Remissão , Neoplasias Retroperitoneais/tratamento farmacológico , Sarcoma Sinovial/tratamento farmacológico , Sarcoma Sinovial/epidemiologia , Sarcoma Sinovial/genética , Sarcoma Sinovial/radioterapia , Estenose Espinal/etiologia , Translocação Genética , Vincristina/administração & dosagem
8.
Med Sci Sports Exerc ; 39(5): 816-20, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17468579

RESUMO

INTRODUCTION: Creatine kinase, found in osteoblasts, is an enzyme that is upregulated in response to interventions that enhance bone mass accretion. Creatine monohydrate supplementation can increase fat-free mass in young healthy men and women and can reduce markers of bone breakdown in boys with Duchenne muscular dystrophy. PURPOSE: The objective of this study was to determine the influence of supplementation with creatine monohydrate on bone structure and function in growing rats, to establish a therapeutic model. MATERIALS AND METHODS: Creatine monohydrate (2% w.w.) (CR; N = 16) or standard rat chow (CON; N = 16) was fed to Sprague-Dawley rats beginning at 5 wk of age, for 8 wk. Bone mineral density (BMD) and content (BMC) were assessed using dual-energy x-ray absorptiometry at the beginning and end of the protocol. The rats were sacrificed, and one femur was removed for the determination of mechanical properties. RESULTS: The CR-treated rats showed greater lumbar BMD and femoral bending load at failure compared with the CON rats (P < 0.05). CONCLUSIONS: Together, these data suggest that creatine monohydrate potentially has a beneficial influence on bone function and structure; further investigation is warranted into its effect on bone functional properties and its effects in disorders associated with bone loss.


Assuntos
Densidade Óssea/efeitos dos fármacos , Creatina/farmacologia , Absorciometria de Fóton , Animais , Suplementos Nutricionais , Masculino , Ontário , Ratos , Ratos Sprague-Dawley
9.
Hum Gene Ther ; 14(11): 1065-77, 2003 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-12885346

RESUMO

Inhibition of angiogenesis has led to tumor suppression in several cancer models. Although administering purified recombinant antiangiogenic product is effective, alternative approaches through genetic manipulation may be more cost-effective. We propose to implant nonautologous recombinant cells secreting angiostatin for systemic delivery of angiostatin in cancer treatment. These cells are protected from graft rejection in alginate microcapsules to function as "micro-organs" to deliver angiostatin in vivo. This approach was tested by implanting encapsulated mouse myoblast C2C12 cells genetically modified to secrete angiostatin into mice bearing solid tumor. Angiostatin was detected in sera of the treated mice. Efficacy was demonstrated by suppression of palpable tumor growth and improved survival. At autopsy, angiostatin localized to residual tumors and high levels of angiostatic activity were detected in tumor extracts. Tumor tissues showed increased apoptosis and necrosis compared with those from untreated or mock-treated mice. Immunohistochemical staining against von Willebrand factor, an endothelial cell marker, showed that within tumors from the treated mice, the neovasculature was poorly defined by endothelial cells, many of which were undergoing apoptosis. However, the tumors eventually developed neovasculature independent of endothelial cells. Such vascular mimicry would account for the lack of long-term efficacy despite persistent angiostatin delivery. In conclusion, implantation with nonautologous microencapsulated cells is feasible for systemic delivery of angiostatin, resulting in localization of angiostatin to tumors and targeted apoptosis of the endothelial cells. Clinical efficacy was demonstrated by suppression of tumor growth and extension of life span. Although the potential of this cell-based approach for angiostatin-mediated cancer therapy is confirmed, long-term efficacy must take into account the possible escape by some tumors from angiogenesis inhibition.


Assuntos
Inibidores da Angiogênese , Neoplasias Experimentais/terapia , Fragmentos de Peptídeos/genética , Plasminogênio/genética , Polilisina/análogos & derivados , Alginatos/química , Angiostatinas , Animais , Apoptose , Linhagem Celular , Transplante de Células/métodos , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Feminino , Engenharia Genética , Rejeição de Enxerto/prevenção & controle , Imuno-Histoquímica , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos C57BL , Mioblastos/metabolismo , Mioblastos/transplante , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Polilisina/química , Células Tumorais Cultivadas , Fator de von Willebrand/análise , Fator de von Willebrand/imunologia
10.
Hum Gene Ther ; 15(10): 945-59, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15585110

RESUMO

An alternative form of gene therapy involves immunoisolation of a nonautologous cell line engineered to secrete a therapeutic product. Encapsulation of these cells in a biocompatible polymer serves to protect these allogeneic cells from host-versus-graft rejection while recombinant products and nutrients are able to pass by diffusion. This strategy was applied to the treatment of cancer with some success by delivering either interleukin 2 or angiostatin. However, as cancer is a complex, multifactorial disease, a multipronged approach is now being developed to attack tumorigenesis via multiple pathways in order to improve treatment efficacy. A combination of immunotherapy with angiostatic therapy was investigated by treating B16-F0/neu melanoma-bearing mice with intraperitoneally implanted, microencapsulated mouse myoblasts (C2C12) genetically modified to deliver angiostatin and an interleukin 2 fusion protein (sFvIL-2). The combination treatment resulted in improved survival, delayed tumor growth, and increased histological indices of antitumor activity (apoptosis and necrosis). In addition to improved efficacy, the combination treatment also ameliorated some of the undesirable side effects from the individual treatments that have led to the previous failure of the single treatments, for example, inflammatory response to IL-2 or vascular mimicry due to angiostatin. In conclusion, the combination of immuno- and antiangiogenic therapies delivered by immunoisolated cells was superior to individual treatments for antitumorigenesis activity, not only because of their known mechanisms of action but also because of unexpected protection against the adverse side effects of the single treatments. Thus, the concept of a "cocktail" strategy, with microencapsulation delivering multiple antitumor recombinant molecules to improve efficacy, is validated.


Assuntos
Inibidores da Angiogênese/farmacologia , Imunoterapia/métodos , Neoplasias/genética , Neoplasias/terapia , Angiostatinas/química , Angiostatinas/genética , Angiostatinas/metabolismo , Animais , Apoptose , Linhagem Celular , Sobrevivência Celular , Citocinas/metabolismo , Composição de Medicamentos , Endotélio Vascular/citologia , Ensaio de Imunoadsorção Enzimática , Terapia Genética/métodos , Imuno-Histoquímica , Interleucina-2/genética , Interleucina-2/metabolismo , Ativação Linfocitária , Melanoma Experimental/terapia , Camundongos , Camundongos Endogâmicos C57BL , Necrose , Proteínas Recombinantes/química , Baço/metabolismo , Linfócitos T/metabolismo , Linfócitos T Citotóxicos/metabolismo , Fatores de Tempo , Transgenes , Fator de von Willebrand/metabolismo
11.
Hum Gene Ther ; 13(10): 1157-66, 2002 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12133269

RESUMO

A novel approach to cancer gene therapy is to implant microcapsules containing nonautologous cells engineered to secrete molecules with antineoplastic properties. The efficacy of this treatment is now tested in a mouse model bearing HER-2/neu-positive tumors. Nonautologous mouse myoblasts (C(2)C(12)) were genetically modified to secrete interleukin-2 linked to the Fv region of a humanized antibody with affinity to HER-2/neu. The resulting fusion protein, sFvIL-2, would encompass immune-stimulatory cytokine activity now targeted to the HER-2/neu-expressing tumor. These recombinant cells were then immunoprotected with alginate-poly-L-lysine-alginate microcapsules before implantation into tumor-bearing mice. Treatment with these encapsulated cells led to a delay in tumor progression and prolonged survival of the animals. The long-term efficacy was limited by an inflammatory reaction against the implanted microcapsules probably because of the secreted cytokine and antigenic response against the xenogeneic fusion protein itself. However, over the short term (initial 2 weeks), efficacy was confirmed when a significant amount of biologically active interleukin-2 was detected systemically, and targeting of the fusion protein to the HER-2/neu-expressing tumor was shown immunohistochemically. The tumor suppression in the treated animals was associated with increased apoptosis and necrosis in the tumor tissue, thus demonstrating successful targeting of the antiproliferative effect to the tumors by this delivery paradigm. In conclusion, this new approach to systemic cancer gene therapy needs to be modified to provide long-term delivery, but has demonstrated short-term efficacy and potential to become a cost-effective, benign, and non-viral-based adjunct to the current armory of anticancer strategies.


Assuntos
Terapia Genética/métodos , Região Variável de Imunoglobulina/genética , Interleucina-2/genética , Neoplasias/terapia , Animais , Western Blotting , Linhagem Celular , Transplante de Células , Composição de Medicamentos , Estudos de Viabilidade , Feminino , Humanos , Região Variável de Imunoglobulina/uso terapêutico , Interleucina-2/uso terapêutico , Melanoma Experimental/terapia , Camundongos , Camundongos Endogâmicos C57BL , Receptor ErbB-2/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/uso terapêutico
13.
Sci Transl Med ; 4(119): 119ra13, 2012 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-22301554

RESUMO

Massage therapy is commonly used during physical rehabilitation of skeletal muscle to ameliorate pain and promote recovery from injury. Although there is evidence that massage may relieve pain in injured muscle, how massage affects cellular function remains unknown. To assess the effects of massage, we administered either massage therapy or no treatment to separate quadriceps of 11 young male participants after exercise-induced muscle damage. Muscle biopsies were acquired from the quadriceps (vastus lateralis) at baseline, immediately after 10 min of massage treatment, and after a 2.5-hour period of recovery. We found that massage activated the mechanotransduction signaling pathways focal adhesion kinase (FAK) and extracellular signal-regulated kinase 1/2 (ERK1/2), potentiated mitochondrial biogenesis signaling [nuclear peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α)], and mitigated the rise in nuclear factor κB (NFκB) (p65) nuclear accumulation caused by exercise-induced muscle trauma. Moreover, despite having no effect on muscle metabolites (glycogen, lactate), massage attenuated the production of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and reduced heat shock protein 27 (HSP27) phosphorylation, thereby mitigating cellular stress resulting from myofiber injury. In summary, when administered to skeletal muscle that has been acutely damaged through exercise, massage therapy appears to be clinically beneficial by reducing inflammation and promoting mitochondrial biogenesis.


Assuntos
Mediadores da Inflamação/metabolismo , Massagem , Mecanotransdução Celular , Mitocôndrias Musculares/metabolismo , Contração Muscular , Doenças Musculares/terapia , Esforço Físico , Músculo Quadríceps/metabolismo , Biópsia , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Quinase 1 de Adesão Focal/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Proteínas de Choque Térmico/metabolismo , Humanos , Interleucina-6/metabolismo , Masculino , Mecanotransdução Celular/genética , Mitocôndrias Musculares/patologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Doenças Musculares/genética , Doenças Musculares/metabolismo , Doenças Musculares/patologia , Doenças Musculares/fisiopatologia , NADH Desidrogenase/metabolismo , NF-kappa B/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Ontário , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Fosforilação , Músculo Quadríceps/patologia , Músculo Quadríceps/fisiopatologia , Reação em Cadeia da Polimerase em Tempo Real , Recuperação de Função Fisiológica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Fatores de Transcrição/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adulto Jovem
14.
Muscle Nerve ; 33(1): 66-77, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16149047

RESUMO

Corticosteroid therapy for Duchenne muscular dystrophy is effective but associated with long-term side effects. To determine the potential therapeutic benefit from four nutritional compounds (creatine monohydrate, conjugated linoleic acid, alpha-lipoic acid, and beta-hydroxy-beta-methylbutyrate) alone, in combination, and with corticosteroids (prednisolone), we evaluated the effects on several variables in exercising mdx mice. Outcome measures included grip strength, rotarod performance, serum creatine kinase levels, muscle metabolites, internalized myonuclei, and retroperitoneal fat pad weight. In isolation, each nutritional treatment showed some benefit, with the combination therapy showing the most consistent benefits. Prednisolone and the combination therapy together provided the most consistent evidence of efficacy; increased peak grip strength (P < 0.05), decreased grip strength fatigue (P < 0.05), decreased number of internalized myonuclei (P < 0.01), and smaller retroperitoneal fat pad stores (P < 0.001). This study provided evidence for therapeutic benefit from a four-compound combination therapy alone, and in conjunction with corticosteroids in the mdx model of DMD.


Assuntos
Creatinina/uso terapêutico , Suplementos Nutricionais , Distrofia Muscular de Duchenne/dietoterapia , Prednisolona/uso terapêutico , Animais , Peso Corporal , Creatina Quinase/sangue , Creatinina/administração & dosagem , Ácido Linoleico/administração & dosagem , Ácido Linoleico/uso terapêutico , Camundongos , Camundongos Endogâmicos mdx , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/tratamento farmacológico , Aptidão Física , Prednisolona/administração & dosagem , Teste de Desempenho do Rota-Rod , Ácido Tióctico/administração & dosagem , Ácido Tióctico/uso terapêutico , Resultado do Tratamento , Valeratos/administração & dosagem , Valeratos/uso terapêutico
15.
Can J Physiol Pharmacol ; 80(10): 1008-14, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12450068

RESUMO

Corticosteroids are used as chemotherapeutic agents in many medical conditions, despite many common and potentially serious side effects. Supplementation with creatine monohydrate (CrM) can increase strength and lean body mass in humans and, therefore, may be a viable countermeasure to the side effects of corticosteroids. Therefore, the purpose of this study was to determine if CrM could prevent the attenuation of growth associated with corticosteroid administration. Forty male Sprague-Dawley rats were randomized to the following groups: control (CON, n = 10), 7 mg methylprednisolone x kg(-1) x week(-1) (PRED, n = 10), 2% CrM in diet (CD, n = 10), or CrM and methylprednisolone (CD-PRED, n = 10). Animals received either a weekly sham injection (saline; CON and CD) or an injection of methylprednisolone (PRED and CD-PRED) for 6 weeks. At the completion of the 6th week, body composition was determined and skeletal muscles were collected. Weight gain was attenuated in PRED as compared with all other groups (P < 0.05). Muscle total creatine and phosphocreatine were greater in the extensor digitorum longus in the CD and CD-PRED groups as compared with the CON and PRED groups (P < 0.05); however, total creatine and phosphocreatine in the soleus were not different. Mean fiber area was greater in type II fibers from the extensor digitorum longus in the CD and CD-PRED groups as compared with the CON and PRED groups (P < 0.05); no treatment effect was seen in the soleus. In conclusion, CrM supplementation prevented the attenuation of growth associated with corticosteroids and also increased type II muscle fiber area. These results could have important clinical implications for several patient populations commonly treated with corticosteroids, and further work is required to determine the specific mechanisms underlying the physiological effects that were observed.


Assuntos
Creatina/farmacologia , Suplementos Nutricionais , Glucocorticoides/efeitos adversos , Crescimento/efeitos dos fármacos , Metilprednisolona/efeitos adversos , Animais , Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Masculino , Fibras Musculares de Contração Rápida/efeitos dos fármacos , Fibras Musculares de Contração Rápida/patologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Ratos , Ratos Sprague-Dawley
16.
Crit Care Med ; 32(12): 2471-5, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15599153

RESUMO

OBJECTIVES: To compare the effects of low vs. high tidal volume (Vt) with three positive end-expiratory pressure (PEEP) strategies on activated neutrophil influx into the lung. DESIGN: Prospective, randomized controlled animal study. SETTING: Animal laboratory in a university hospital. SUBJECTS: Newborn piglets. INTERVENTIONS: Surfactant-depleted piglets were randomized in littermate pairs; to PEEP of either 0 (zero end-expiratory pressure [ZEEP]; n = 6), 8 cm H2O (PEEP 8; n = 5), or 1 cm H2O above the lower inflection point (LIP) (PEEP>LIP; n = 6). Within each pair piglets were randomized to a low VT (5-7 mL/kg) or high VT strategy (17-19 mL/kg). After 4 hrs of mechanical ventilation, 18-fluorodeoxyglucose (18FDG) was injected and positron emission tomography scanning was performed. MEASUREMENTS AND MAIN RESULTS: VT and PEEP changes on influx constants of 18FDG were assessed by analysis of variance. A within-litter comparison of Vt was nonsignificant (p = .50). A between-litter comparison, ordered in linear trend rank, from ZEEP, to PEEP 8, to PEEP>LIP, showed a strong effect of PEEP on influx constant (p = .019). CONCLUSIONS: PEEP set above the LIP on the inspiratory limb of the pressure-volume curve affords a stronger lung protection than VT strategy.


Assuntos
Neutrófilos/fisiologia , Respiração com Pressão Positiva/métodos , Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/terapia , Animais , Animais Recém-Nascidos , Biópsia por Agulha , Movimento Celular , Modelos Animais de Doenças , Feminino , Imuno-Histoquímica , Complacência Pulmonar , Masculino , Tomografia por Emissão de Pósitrons , Probabilidade , Ventilação Pulmonar , Distribuição Aleatória , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Sensibilidade e Especificidade , Volume de Ventilação Pulmonar
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