Academic literature on the topic 'Skeletal muscle biopsy samples'
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Journal articles on the topic "Skeletal muscle biopsy samples"
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Kurt, YaseminGulcan, Bulent Kurt, Omer Ozcan, Turgut Topal, Abdullah Kilic, Tuba Muftuoglu, Cengizhan Acikel, et al. "Preservative solution for skeletal muscle biopsy samples." Annals of Indian Academy of Neurology 18, no. 2 (2015): 187. http://dx.doi.org/10.4103/0972-2327.150601.
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Wendling, P. S., S. J. Peters, G. J. Heigenhauser, and L. L. Spriet. "Variability of triacylglycerol content in human skeletal muscle biopsy samples." Journal of Applied Physiology 81, no. 3 (September 1, 1996): 1150–55. http://dx.doi.org/10.1152/jappl.1996.81.3.1150.
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The variability of the triacylglycerol store in human skeletal muscle (TGm) was examined using the needle biopsy technique. In 13 subjects, three biopsies were sampled from the vastus lateralis muscle of one leg at rest and after 90 min of cycling at 65% of maximal O2 uptake on one or two occasions. Visible fat and blood were removed before the samples were frozen, and remaining blood, connective tissue, and fat were removed from freeze-dried fiber bundles. TGm content was measured in two aliquots of powdered muscle from each biopsy. Within-biopsy variability was low at 6%. Despite precautions, many biopsies from inactive subjects were contaminated with adipose tissue. The TGm between-biopsy coefficient of variation (CV) was 23.5 +/- 14.6% (SD, n = 24) for rest and exercise time points where three noncontaminated biopsies existed. The between-biopsy variability at rest (19.8 +/- 7.9%, n = 10) was not significantly different from that at exercise (26.1 +/- 17.4%, n = 14). The muscle glycogen between-biopsy CV for rest and exercise time points was 10.0 +/- 10.3%. The resting TGm content was 26.3 +/- 4.3 mmol/kg dry muscle, and the net utilization during the 90 min of exercise was less than the between-biopsy variability. It is concluded that the TGm store measured in repeated biopsies of human skeletal muscle is variable, with a CV of 20-26%. Therefore, because of this high variability, only changes greater than approximately 24% of resting TGm content may be considered meaningful.
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Braga, Sérgio De Almeida, Felipe Gomes Ferreira Padilha, and Ana Maria Reis Ferreira. "Needle muscle biopsy: technique validation and histological and histochemical methods for evaluating canine skeletal muscles." Semina: Ciências Agrárias 38, no. 2 (May 2, 2017): 765. http://dx.doi.org/10.5433/1679-0359.2017v38n2p765.
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This study evaluated the needle muscle biopsy technique using a 6G Bergström percutaneous needle combined with histological and histochemical methods to analyze the skeletal muscle of dogs. There are few studies about canine skeletal muscles and a lack of reports in the literature about tissue collection and analysis for canine species. Evaluation of 32 German Shepherd samples collected from the gluteus medius, at a depth of 3 cm, was performed. The choice of gluteus medius and the 3-cm depth provided good quantity fragments with sufficient sizes (3–5 mm), which permitted optimal visualization of muscle fibers. Myosin ATPase, at pH 9.4, 4.6, and 4.3, and SDH reactions revealed that all muscle samples analyzed had fibers in the classic mosaic arrangement, enabling counting and typification. The mean percentages of fibers were 29.95% for type I and 70.05% for type II. On the basis of these results, we concluded that the percutaneous needle biopsy technique for canine skeletal muscles is a safe and easy procedure that obtains fragments of proper sizes, thereby enabling the study of muscle fibers. Standardization of the muscle of choice and the depth of muscle sample collection significantly contributed to this success. This is an important method to evaluate muscle fiber types of dogs and diagnose important diseases affecting the skeletal muscles.
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Parker, Kenneth C., Ronan J. Walsh, Mohammad Salajegheh, Anthony A. Amato, Bryan Krastins, David A. Sarracino, and Steven A. Greenberg. "Characterization of Human Skeletal Muscle Biopsy Samples Using Shotgun Proteomics†." Journal of Proteome Research 8, no. 7 (July 6, 2009): 3265–77. http://dx.doi.org/10.1021/pr800873q.
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Soderlund, K., and E. Hultman. "Effects of delayed freezing on content of phosphagens in human skeletal muscle biopsy samples." Journal of Applied Physiology 61, no. 3 (September 1, 1986): 832–35. http://dx.doi.org/10.1152/jappl.1986.61.3.832.
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The concentrations of ATP, phosphocreatine (PCr), creatine, and lactate were determined in muscle biopsy samples frozen immediately or after a delay of 1–6 min. During the delay the samples were exposed to normal air or a gas mixture of 6.5% CO2-93.5% O2. The ATP content was unchanged, but PCr increased significantly from 72 mmol after rapid freezing to 85 mmol X kg dry muscle-1 during the 1st min in air. The lactate concentration increased (2.8 to 5.2 mmol X kg-1). If muscles were made anoxic by circulatory occlusion for 4–6 min before sampling, no increase in PCr was observed. Direct homogenization of fresh tissue in perchloric acid gave the same ATP, PCr, and lactate contents as frozen samples. It is concluded that the ATP and PCr contents in muscle are unaffected by freezing but that the biopsy procedure activates the energy utilization processes resulting in PCr decrease. It is suggested that the muscle PCr content after a 1-min delay in tissue freezing corresponds to the level in resting fresh muscle.
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Güttsches, Anne-Katrin, Robert Rehmann, Anja Schreiner, Marlena Rohm, Johannes Forsting, Martijn Froeling, Martin Tegenthoff, Matthias Vorgerd, and Lara Schlaffke. "Quantitative Muscle-MRI Correlates with Histopathology in Skeletal Muscle Biopsies." Journal of Neuromuscular Diseases 8, no. 4 (July 30, 2021): 669–78. http://dx.doi.org/10.3233/jnd-210641.
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Background: Skeletal muscle biopsy is one of the gold standards in the diagnostic workup of muscle disorders. By histopathologic analysis, characteristic features like inflammatory cellular infiltrations, fat and collagen replacement of muscle tissue or structural defects of the myofibers can be detected. In the past years, novel quantitative MRI (qMRI) techniques have been developed to quantify tissue parameters, thus providing a non-invasive diagnostic tool in several myopathies. Objective: This proof-of-principle study was performed to validate the qMRI-techniques to skeletal muscle biopsy results. Methods: Ten patients who underwent skeletal muscle biopsy for diagnostic purposes were examined by qMRI. Fat fraction, water T2-time and diffusion parameters were measured in the muscle from which the biopsy was taken. The proportion of fat tissue, the severity of degenerative and inflammatory parameters and the amount of type 1- and type 2- muscle fibers were determined in all biopsy samples. The qMRI-data were then correlated to the histopathological findings. Results: The amount of fat tissue in skeletal muscle biopsy correlated significantly with the fat fraction derived from the Dixon sequence. The water T2-time, a parameter for tissue edema, correlated with the amount of vacuolar changes of myofibers and endomysial macrophages in the histopathologic analysis. No significant correlations were found for diffusion parameters. Conclusion: In this proof-of-principle study, qMRI techniques were related to characteristic histopathologic features in neuromuscular disorders. The study provides the basis for further development of qMRI methods in the follow-up of patients with neuromuscular disorders, especially in the context of emerging treatment strategies.
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Braund, K. G., and K. A. Amling. "Muscle Biopsy Samples for Histochemical Processing: Alterations Induced by Storage." Veterinary Pathology 25, no. 1 (January 1988): 77–82. http://dx.doi.org/10.1177/030098588802500111.
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Skeletal muscle samples from two healthy dogs were stored in ice at 0 C for up to 30 hours to examine the influence of time on cell morphology and morphometry. Cytochemical and histochemical properties of muscle to 18 hours were not markedly different from fresh frozen tissue. Samples stored to 30 hours were still satisfactory, despite a decline and unevenness in depth of staining. Morphometry from samples stored at 0 C for 6 hours or longer is not recommended, due to the statistically significant increase in diameter (from 21 to 25%) of type I and type II fibers.
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Graham, T. E., B. Wolfe, and J. K. Barclay. "Active skeletal muscle metabolism and tension production: the influence of biopsies." Canadian Journal of Physiology and Pharmacology 71, no. 3-4 (March 1, 1993): 241–46. http://dx.doi.org/10.1139/y93-038.
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The influence of repeated sampling by the biopsy technique on skeletal muscle's metabolic and force-output responses was studied using the in situ canine gastrocnemius preparation. The left muscle was stimulated (8 V, 0.2 ms) for 1 h at 3 Hz. In the biopsy series (n = 9) muscle samples were taken at rest, and at 0.5, 2, 5, 15, 30, 45, and 60 min of stimulation. In the control series (n = 8) the left and right muscles were quick-frozen in N2 immediately after the 60 min of stimulation. The two series were not different in blood flow, [Formula: see text], arterial or venous [H+], muscle glycogen, or lactate release throughout the 60 min of activity. The lactate release was transient and was associated with an accumulation of intramuscular lactate and a period of rapid glycogenolysis. The biopsy series had a modest but significantly (p < 0.05) higher muscle lactate concentration both at rest and at the end of the contractions. The biopsy series also had less (p < 0.05) tension development throughout the hour; however, the O2 cost per unit of tension development was not different between groups, nor was the rate of tension decline over time different. This together with the similarities in perfusion, carbohydrate use, and lactate metabolism suggests that repeated biopsies had minimal impact on the muscle. The technique allows the collection of data over time; this improves the detail of experiments and means that fewer animals are required for a study.Key words: glycolysis, lactate, hydrogen ion, fatigue, muscle glycogen.
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Constantin-Teodosiu, D., G. Cederblad, and E. Hultman. "PDC activity and acetyl group accumulation in skeletal muscle during isometric contraction." Journal of Applied Physiology 74, no. 4 (April 1, 1993): 1712–18. http://dx.doi.org/10.1152/jappl.1993.74.4.1712.
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The activity of pyruvate dehydrogenase complex (PDC) was studied in the human quadriceps femoris muscle during isometric contraction induced by intermittent electrical stimulation at 20 Hz. Muscle biopsy samples were obtained at rest and after 10, 20, and 46 contractions. The active form of PDC (PDCa) increased from a mean value of 26% of the total PDC at rest to mean values of 46, 78, and 80%, respectively. Muscle biopsy samples were also obtained at rest, after 46 contractions with limb blood flow intact or occluded, and after 2 min of oxidative recovery. In another experiment, muscle biopsy samples were obtained at rest, after 10 min of resting ischemia, and after 46 contractions with limb blood flow occluded. The transformation of PDC to PDCa was nearly complete, regardless of whether the blood flow was intact or occluded. However, the accumulation of acetyl groups observed during stimulation with intact blood flow was abolished when the blood flow was occluded. The absence of NADH oxidation during anoxia had no effect on the contraction-induced transformation of PDC to PDCa, but it inhibited the flux through the enzyme reaction.
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Berthon, Phanélie M., Richard A. Howlett, George J. F. Heigenhauser, and Lawrence L. Spriet. "Human skeletal muscle carnitine palmitoyltransferase I activity determined in isolated intact mitochondria." Journal of Applied Physiology 85, no. 1 (July 1, 1998): 148–53. http://dx.doi.org/10.1152/jappl.1998.85.1.148.
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This study was designed to compare the activity of skeletal muscle carnitine palmitoyltransferase I (CPT I) in trained and inactive men ( n = 14) and women ( n = 12). CPT I activity was measured in intact mitochondria, isolated from needle biopsy vastus lateralis muscle samples (∼60 mg). The variability of CPT I activity determined on two biopsy samples from the same leg on the same day was 4.4, whereas it was 7.0% on two biopsy samples from the same leg on different days. The method was sensitive to the CPT I inhibitor malonyl-CoA (88% inhibition) and therefore specific for CPT I activity. The mean CPT I activity for all 26 subjects was 141.1 ± 10.6 μmol ⋅ min−1 ⋅ kg wet muscle (wm)−1 and was not different when all men vs. all women (140.5 ± 15.7 and 142.2 ± 14.5 μmol ⋅ min−1 ⋅ kg wm−1, respectively) were compared. However, CPT I activity was significantly higher in trained vs. inactive subjects for both men (176.2 ± 21.1 vs. 104.1 ± 13.6 μmol ⋅ min−1 ⋅ kg wm−1) and women (167.6 ± 14.1 vs. 91.2 ± 9.5 μmol ⋅ min−1 ⋅ kg wm−1). CPT I activity was also significantly correlated with citrate synthase activity (all subjects, r = 0.76) and maximal oxygen consumption expressed in milliliters per kilogram per minute (all subjects, r = 0.69). The results of this study suggest that CPT I activity can be accurately and reliably measured in intact mitochondria isolated from human muscle biopsy samples. CPT I activity was not affected by gender, and higher activities in aerobically trained subjects appeared to be the result of increased mitochondrial content in both men and women.
Dissertations / Theses on the topic "Skeletal muscle biopsy samples"
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Pillitteri, Paul J. "Regeneration of Rat Skeletal Muscle Following a Muscle Biopsy." Ohio University / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1118087917.
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Laurentino, Gilberto Candido. "Treinamento de força com oclusão vascular: adaptações neuromusculares e moleculares." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/39/39132/tde-13082010-103300/.
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Estudos têm mostrado que o treinamento de força de baixa intensidade com oclusão vascular (TFOV) tem apresentado resultados similares nos ganhos de força e hipertrofia comparado ao treinamento de força (TF) de alta intensidade. O objetivo deste estudo foi comparar os efeitos de três diferentes programas de TF nos ganhos de força e hipertrofia musculares e na expressão da miostatina (MSTN) e seus antagonistas. Para isso, vinte e nove jovens do sexo masculino, sem experiência em TF, foram recrutados e divididos randomicamente nos grupos: treinamento de força de baixa intensidade sem oclusão (BI), treinamento de força de baixa intensidade com oclusão (BIO) e treinamento de força de alta intensidade sem oclusão (AI). Os grupos BIO e BI treinaram com intensidade de 20% 1RM, enquanto o grupo AI treinou com intensidade de 80% 1RM. A ANOVA one way foi utilizada para testar as diferenças percentuais nos ganhos de força (1RM) e na área de secção transversa (AST) do músculo quadríceps femoral. O modelo misto para análise das medidas repetidas foi utilizado para testar as diferenças nas variáveis miostatina (MSTN), folistatina-3 (FLST-3), SMAD-7 e GASP-1 nos grupos BI, BIO e AI nas condições pré e pós-treinamento. Os resultados mostraram que os aumentos de força e hipertrofia musculares nos grupos BIO e AI foram similares, entretanto superiores ao grupo BI. Esses resultados podem ser atribuídos a maior diminuição na expressão da MSTN nos grupos BIO (45%) e AI (41%) comparados com o grupo BI (16%) e o aumento na expressão dos genes que antagonizam sua atividade (SMAD-7, FLST-3 e GASP-1). Podemos concluir que a inibição na atividade da MSTN dos grupos BIO e AI podem responder em parte a similaridade nos ganhos de força e hipertrofia entre os grupos e a diferença para o grupo BIIt has been demonstrated that low intensity training associated to vascular occlusion (LIO) promotes similar gains in strength and muscle mass when compared to high intensity strength training (HI). The aim of the present study was to evaluate the effect of three different training programs on skeletal muscle hypertrophy and atrophy related gene expression. Twenty nine young male, with no previous experience in strength training were randomly allocated in three groups: low intensity strength training (i.e. 20% - 1-RM) (LI); low intensity strength training associated to vascular occlusion (i.e. 20% - 1-RM) (LIO); high intensity strength training (HI) (i.e. 80% - 1-RM). One-way ANOVA was used to assess differences in % delta change values of 1-RM and cross sectional area (CSA) of the quadriceps femoris. Mixed model analysis was used to compare myostatin (MSTN), folistatyn-3 (FLST-3), SMAD-7 e GASP-1 changes between groups pre and post training. Results demonstrated similar increases in strength and muscle hypertrophy for LIO and HI groups. Moreover, such increases were significantly greater when compared to LI. These results may be, at least in part, explained by a significant decrease in MSTN mRNA expression in LIO (45%) and HI (41%) when compared to LI (16%); additionally, SMAD-7; FLST-3 and GASP-1 mRNA expression were significantly increased. In conclusion, LIO training promotes similar gains than HI training. The results may be explained by changes in MSTN and related genes mRNA expression
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Widman, Lars. "Skeletal muscle potassium and magnesium in diuretic treated patients : effects of potassium - sparing diuretics of magnesium supplementation." Doctoral thesis, Umeå universitet, Medicin, 1988. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100556.
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Müller-Witt, Adriane [Verfasser]. "Heat shock protein 72 expression in skeletal muscle samples from cachectic- and non-cachectic-pancreatic cancer patients / Adriane Müller-Witt." Ulm : Universität Ulm. Medizinische Fakultät, 2015. http://d-nb.info/1066305412/34.
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Gitiaux, Cyril. "Role of vascular plasticity in muscle remodeling in the child." Thesis, Sorbonne Paris Cité, 2015. http://www.theses.fr/2015PA05T005/document.
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Le muscle strié squelettique est un tissu richement vascularisé. Au delà de l'apport en oxygène et en nutriments, de nouvelles fonctions des vaisseaux ont été récemment identifiées, par le biais des interactions établies entre les cellules du vaisseau (cellules endothéliales) et les cellules du muscle, en particulier les cellules souches musculaires (cellules satellites). Celles-ci interagissent étroitement avec les cellules endothéliales pour leur expansion et leur différenciation, puis avec les cellules péri-endothéliales pour leur auto-renouvellement et leur retour à la quiescence. Les vaisseaux participent ainsi au contrôle de l’homéostasie du muscle squelettique. Grâce à ces interactions, les cellules vasculaires jouent donc un rôle central dans le remodelage tissulaire après un phénomène destructif, survenant par exemple au cours d’un trauma ou d’une myopathie. Pour étudier, les mécanismes de la plasticité vasculaire au cours du remodelage tissulaire, deux situations paradigmatiques de muscle en régénération chez l’enfant : la dermatomyosite juvénile (DMJ) et la dystrophie musculaire de Duchenne (DMD) ont été étudiées. Il existe, dans ces deux pathologies une souffrance musculaire associée à des cycles de nécrose/régénération. Elles se différencient par leur plasticité vasculaire et par leur évolution. En effet, la DMJ, la myopathie inflammatoire la plus fréquente de l’enfant est caractérisée par une vasculopathie avec perte en capillaires. L’évolution peut être favorable avec restitution ad integrum du muscle. La DMD est une myopathie génétique conduisant à une dégradation progressive de la force musculaire associée à une néovascularisation compensatrice. Le volet clinique/histologique incluant une analyse multiparamétrique des critères évolutifs cliniques et de réponse thérapeutique couplée à une réévaluation des données histologiques de la DMJ (analyse morphométrique des muscles DMJ) a permis de montrer qu’il existait des sous groupes phénotypiques homogènes de sévérité différente dans la DMJ. Le degré de sévérité clinique est relié à la gravité de la vasculopathie musculaire Par ailleurs, des marqueurs cliniques et histologiques simples permettant de repérer au diagnostic les patients nécessitant une escalade thérapeutique rapide (CMAS>34, atteinte gastrointestinale, fibrose endomysiale musculaire au diagnostic) ont été identifiés. Le volet cellulaire a permis l’identification in vitro des interactions cellulaires spécifiques et différentielles des myoblastes issues de patients DMD et DMJ sur les cellules endothéliales normales par l’analyse de leur rôle sur la prolifération, migration et différenciation des cellules vasculaires. Dans la DMD, les myoblastes entrainent une réponse angiogénique importante mais non efficace (néovascularisation anarchique). Dans la DMJ, les myoblastes participent efficacement à la reconstruction vasculaire notamment via la sécrétion de facteurs proangiogéniques. Ces résultats ont été renforcés par analyse transcriptomique effectuée à partir de cellules endothéliales et satellites isolées de muscles de patients confirmant le rôle central de la vasculopathie associée à un contexte inflammatoire spécifique lié à l’interféron dans la physiopathologie de la DMJ et montrant dans la DMD une dérégulation de l’homéostasie normale des interactions vaisseau-muscle avec mise en jeu d’un remodelage tissulaire non efficace. Ces données permettent d'identifier de nouvelles fonctions des cellules vasculaires dans le remodelage du muscle strié squelettique au cours des pathologies musculaires de l'enfant, et devraient ouvrir la voie à de nouvelles approches thérapeutiquesSkeletal muscle is highly vascularised. Beyond oxygen and nutriment supply, new functions for vessels have been recently identified, through the interactions that vessel cells (endothelial cells) establish with muscle cells, particularly with muscle stem cells (satellite cells). These latter closely interact with endothelial cells for their expansion and their differentiation, then with periendothelial cells for their self-renewal and return to quiescence. During skeletal muscle regeneration endothelial cells reciprocally interact with myogenic cells by direct contact or by releasing soluble factors to promote both myogenesis and angiogenesis processes. Skeletal muscle regeneration typically occurs as a result of a trauma or disease, such as congenital or myopathies. To better understand the role of vessel plasticity in tissue remodeling, we took advantage of two muscular disorders that could be considered as paradigmatic situations of regenerating skeletal muscle in the child: Juvenile Dermatomyositis (JDM), the most frequent inflammatory myopathy and Duchenne Muscular Dystrophy (DMD), the most common type of muscular dystrophy. Although these two muscular disorders share, at the tissue level, similar mechanisms of necrosis-inflammation, they differ regarding the vessel domain. In JDM patients, microvascular changes consist in a destruction of endothelial cells assessed by focal capillary loss. This capillary bed destruction is transient. The tissue remodeling is efficient and muscle may progressively recover its function. By contrast, in DMD, despite an increase of vessels density in an attempt to improve the muscle perfusion, the muscle function progressively alters with age. We identified clinical and pathological markers of severity and predictive factors for poor clinical outcome in JDM by computing a comprehensive initial and follow-up clinical data set with deltoid muscle biopsy alterations controlled by age-based analysis of the deltoid muscle capillarization. We demonstrated that JDM can be divided into two distinctive clinical subgroups. The severe clinical presentation and outcome are linked to vasculopathy. Furthermore, a set of simple predictors (CMAS<34, gastrointestinal involvement, muscle endomysial fibrosis at disease onset) allow early recognition of patients needing rapid therapeutic escalation with more potent drugs. We studied in vitro the specific cell interactions between myogenic cells issued from JDM and DMD patients and normal endothelial cells to explore whether myogenic cells participate to the vessel remodeling observed in the two pathologies. We demonstrated that MPCs possessed angiogenic properties depending on the pathological environment. In DMD, MPCs promoted the development of establishment of an anarchic, although strong, EC stimulation, leading to the formation of weakly functional vessels. In JDM, MPCs enhanced the vessel reconstruction via the secretion of proangiogenic factors. This functional analysis was supported by the transcriptomic analysis consistent with a central vasculopathy in JDM including a strong and specific response to an inflammatory environment. On the contrary, DMD cells presented an unbalanced homeostasis with deregulation of several processes including muscle and vessel development with attempts to recover neuromuscular system by MPCs. To summarize, our data should allow the definition of new functions of vessel cells in skeletal muscle remodelling during muscle pathologies of the child that will open the way to explore new therapeutic options and to gain further insights in the pathogenesis of these diseases
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Guardia, Paolo Gadioli La. "Inibição, por sinvastatina, da respiração mitocondrial de biopsias de musculo esqueletico e figado de ratos." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311233.
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Orientadores: Anibal E. Vercesi, Luciane Carla AlbericiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicaas
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Resumo: Inibidores da 3-hidroxi-3-metilglutaril-CoA redutase (estatinas) são fármacos utilizados para diminuir os níveis plasmáticos de colesterol e são, geralmente, seguros e bem tolerados. Ocasionalmente esses fármacos induzem miotoxicidade, como miopatia e rabdomiólise, e hepatotoxicidade. Neste trabalho investigou-se o mecanismo, in vitro e in vivo, pelo qual as estatinas atuam sobre a respiração mitocondrial de biópsias de músculo esquelético e de fígado de ratos. A incubação (1 hora) de biópsias permeabilizadas de músculo sóleo (2-3 mg) com doses crescentes de sinvastatina reduziu a velocidade de respiração mitocondrial estimulada por ADP ou FCCP de forma dose-dependente e significativa (p<0,05). A inibição causada por 1 |iM de sinvastatina nas velocidades de respiração estimuladas por ADP e FCCP foi de respectivamente cerca de 25% e 27%. Em contraste, não houve alteração significativa na velocidade de respiração de repouso. O efeito de 1|iM de sinvastatina foi inibido pela incubação concomitante com 100 |uM de mevalonato (produto da enzima HMG-CoA redutase), ou 10 |JM de coenzima Q10 (um outro produto da via de síntese do colesterol). A redução na velocidade de respiração também foi inibida pela incubação concomitante com 1 mM de L-carnitina. A incubação com sinvastatina aumentou de forma significativa (p<0,05) a produção de lactato pelas biópsias musculares em cerca de 26%, efeito protegido pela incubação concomitante com mevalonato ou coenzima Q10 ou L-carnitina na mesma concentração descrita anteriormente. Por outro lado, esta mesma concentração de sinvastatina não provocou efeito algum sobre as velocidades de respiração de mitocôndrias isoladas de músculo de ratos. A incubação (1 hora) de biópsias hepáticas (2-3 mg) com doses crescentes de sinvastatina reduziu a respiração mitocondrial estimulada por ADP ou FCCP, sem alterar a respiração de repouso. Sinvastatina (5 uM) inibiu significativamente (p<0,05) a respiração estimulada por ADP e FCCP em cerca de 24% e 29% respectivamente. Esta inibição não foi sensível a 100 |iM de mevalonato ou 10 |iM de coenzima Q10 ou 1 mM de L-carnitina. Biópsias de músculo sóleo de ratos tratados durante 15 dias com 100 mg / kg (gavagem) de sinvastatina apresentaram velocidades de consumo de oxigênio reduzidas em todos os estados respiratórios. Este efeito foi inibido pela administração concomitante de L-carnitina 200 mg / kg (gavagem).
Abstract: 3-Hydroxy-3-methylglutaryl CoA reductase inhibitors (statins) are safe and well-tolerated therapeutic drugs, that occasionally induce myotoxicity such as myopathy and rhabdomyolysis, and hepatotocixity. Here, we investigated in vitro and in vivo the mechanisms of statin-induced toxicity on mitochondrial respiration of rat skeletal muscle and liver biopsies. One hour incubation of permeabilized soleus muscle biopsies (2-3 mg) with increasing doses of simvastatin (1 to 40 |iM) reduced ADP- or FCCP-stimulated mitochondrial respiration rate in a dose-dependent manner. The inhibition of ADP- or FCCP-stimulated mitochondrial respiration rate by simvastatin 1 |iM was 25% and 27%, respectively. No changes in rest respiration rate was observed. Simvastatin (1 |JM) inhibition of muscle respiration was prevented by coincubation with 100 |JM mevalonate, 10 |JM coenzyme Q10 or 1 mM L-carnitine. Simvastatin (1 |JM) also increased lactate production in muscle biopsies by 26%; this effect was prevented by the coincubation with mevalonate, coenzyme Q10 or L-carnitine. At the same concentration, simvastatin did not inhibit the respiration of isolated skeletal muscle mitochondria suggesting that simvastatin effect on mitochondrial respiration is not direct. Incubation (1 hour) of liver biopsies (2-3 mg) with increasing doses of simvastatin reduced ADP- or FCCP-stimulated mitochondrial respiration rate without changes in rest respiration rate. The lowest simvastatin concentration able to reduce liver biopsies respiration rates was 5 |JM, which promoted 24% and 29% inhibition in ADP- or FCCP-stimulated respiration rates, respectively. This was not modified by mevalonate, coenzyme Q10 or L-carnitine. Soleus muscle biopsies from rats treated during 15 days with simvastatin (100 mg/kg, p.o.) presented L-carnite sensitive inhibition of oxygen consumption rate in all respiratory states.
Mestrado
Medicina Experimental
Mestre em Fisiopatologia Médica
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Breda, Ana Paula. "Avaliação da musculatura estriada de membros inferiores na limitação funcional ao exercício em pacientes com hipertensão arterial pulmonar." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/5/5150/tde-20072011-145309/.
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Introdução: A hipertensão arterial pulmonar (HAP) é uma doença progressiva extremamente grave, que evolui com insuficiência cardíaca direita e morte. Apesar do avanço do tratamento farmacológico, o prognóstico permanece reservado com taxa de sobrevida de 86%, 70% e 55% em 1, 3 e 5 anos, respectivamente. A dispnéia progressiva e a intolerância ao exercício são as principais manifestações clínicas e refletem a falência do ventrículo direito. O músculo esquelético periférico parece ser também um dos principais determinantes desta limitação funcional, visto que a redução da oferta de oxigênio e alterações na extração/utilização do oxigênio pelo músculo são diretamente relacionados com a tolerância ao exercício. Existem dois mecanismos potencialmente envolvidos na regulação da oferta de oxigênio, e portanto, na capacidade de exercício: mecanismos centrais (função do coração, pulmão e sistema nervoso autônomo) e mecanismos periféricos (associado ao fluxo sanguíneo periférico e a função do músculo esquelético). Os pacientes com HAP geralmente apresentam baixo débito cardíaco e estado adrenérgico exacerbado. A combinação destas alterações pode resultar em alterações estruturais e funcionais da musculatura estriada periférica. Porém, não existem informações sólidas que nos esclareçam se o acometimento muscular é preditor independente da limitação da capacidade de exercício. Objetivos: (1) Caracterizar o papel da musculatura periférica na limitação funcional em pacientes com HAP. (2) Avaliar o papel do sistema muscular periférico como um fator independente para a limitação ao exercício em HAP. Materiais e métodos: Dezesseis pacientes com HAP foram prospectivamente comparados com 10 indivíduos controle em termos de dados demográficos, qualidade de vida relacionada à saúde e limitação ao exercício, avaliada pelo teste de caminhada de seis minutos, teste cardiopulmonar, dinamometria isocinética e medições de pressão respiratória máxima. Pacientes com HAP também foram submetidos à biópsia do quadríceps, a fim de avaliar as mudanças estruturais. Resultados: Os pacientes com HAP apresentaram pior qualidade de vida (componente físico p<0,001), menor percentagem de massa magra (p=0,044), menor força muscular respiratória (p<0,001), menor resistência e força dos extensores de coxa (p=0,017 e p=0,012, respectivamente) e maior limitação funcional demonstrada pela distância percorrida no teste de caminhada de seis minutos (p<0,001) e pelo teste de exercício cardiopulmonar (p<0,001 para VO2/kg), em comparação ao grupo controle. Estes achados de redução de força e função muscular estão em acordo com os achados de redução da percentagem de fibras do Tipo I à biópsia muscular. O consumo de oxigênio, apresentou correlação com a função da musculatura respiratória e da musculatura extensora de coxa (resistência e força), e com a proporção de fibras oxidativas (Tipo I). O débito cardíaco também apresentou correlação com o VO2. o modelo de análise bivariada demonstrou que a função muscular é preditora independente do VO2 pico, mesmo com a correção para o perfil hemodinâmico. Conclusão: (1) Pacientes com HAP apresentam alteração estrutural e funcional da musculatura estriada periférica, e (2) estas alterações determinam limitação da capacidade global de exercício de forma independente do padrão hemodinâmico característico da HAPIntroduction: Pulmonary arterial hypertension (PAH) is a relentlessly progressive disease that leads to right heart failure and death. Despite advances in pharmacological treatment, prognosis is still poor with survival rates of 86%, 70% and 55% at 1, 3 and 5 years, respectively. Progressive dyspnea and exercise intolerance are the main clinical manifestations and reflect the impairment of right ventricular function. Peripheral skeletal muscle also seems to be a major determinant of functional limitation, as the reduction of oxygen supply and changes in extraction and utilization of oxygen by the muscle are directly associated to exercise tolerance. There are two potential mechanisms involved in the regulation of oxygen supply and therefore in exercise capacity: central (as a function of heart, lung and autonomic nervous system function) and peripheral (associated to peripheral blood flow and skeletal muscle function). Patients with PAH usually present low cardiac output and exacerbated adrenergic state. The combination of these features might result in changes of peripheral skeletal muscle and structure. However, there is no robust information that clearly clarifies whether the muscle involvement is an independent factor for exercise limitation. Objectives: (1) Characterize the role of the peripheral muscles in functional limitation in patients with PAH. (2) Address the role of the peripheral muscle system as an independent factor in exercise limitation in PAH. Materials and methods: Sixteen PAH patients were prospectively compared to 10 control individuals in terms of demographic data, health related quality of life and exercise limitation, assessed by six-minute walk test, cardiopulmonary test, isokinetic dynamometry and maximum respiratory pressure measurements. PAH patients also were submitted to vastus lateralis biopsy in order to assess structural changes. Results: PAH patients presented poorer quality of life (p <0.001), lower percentage of fat free mass (p = 0.044), lower respiratory muscle strength (p <0.001), lower resistance and strength of the extensor of the thigh (p = 0.017 and 0.012, respectively) and greater functional limitation demonstrated by the six-minute walk distance (p <0.001) and at the cardiopulmonary exercise test (p <0.001 for VO2max/kg), as compared to the control group. These findings of reduced muscle strength and function are in agreement with the findings of reduced percentage of Type I fibers at the muscle biopsy. The oxygen consumption correlated to the function of respiratory muscles and of extensor muscles of the thigh (endurance and strength) as well as to the proportion of oxidative fibers (Type I). The cardiac output also correlated with VO2. A bivariate model demonstrated that muscle function is an independent predictor of maximum oxygen consumption, even correcting for the hemodynamic profile. Conclusion: (1) PAH patients present functional and structural changes in peripheral skeletal muscles, and (2) these changes determine overall exercise capacity limitation, independently of the hemodynamic pattern
Books on the topic "Skeletal muscle biopsy samples"
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Atlas of skeletal muscle pathology. Lancaster: MTP Press, 1985.
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Pipitone, Nicolo. Imaging of skeletal muscle. Edited by Hector Chinoy and Robert Cooper. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198754121.003.0014.
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Imaging techniques play a key role in the assessment of patients with the idiopathic inflammatory myopathies (IIM). Magnetic resonance imaging (MRI) can reveal muscle inflammation similarly to muscle scintigraphy and 18F-Fluorodeoxyglucose positron emission tomography, but is also able to visualize findings of chronic muscle damage such as muscle atrophy or fat replacement. Ultrasonography has a more limited role because it can only depict the superficial muscle layers. Imaging findings are not specific to IIM, but in the appropriate clinical context they support the diagnosis. MRI is also useful to target biopsy to affected muscles, thus increasing biopsy yield. In addition, because different myopathies present with different patterns of muscle involvement, imaging studies can provide differential diagnostic clues. Finally, imaging studies—especially MRI—can be used to monitor the effects of treatment by serially evaluating changes in muscle inflammation and damage.
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Mammen, Andrew L., and Jessica R. Nance. Evaluation of hyperCKaemia. Edited by Hector Chinoy and Robert Cooper. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198754121.003.0007.
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Serum creatine kinase (CK) levels may be elevated in patients with muscle weakness or pain. In asymptomatic patients with CK elevations, the focus should be on identifying reversible causes, followed by investigation for inherited muscle diseases. In asymptomatic patients with an incidental finding of elevated CK, clinicians should look for reversible causes, then re-test the CK after 10 days of rest in the absence of potential triggers. If the CK remains markedly elevated and/or electromyography proves myopathic, a muscle biopsy should be considered. Women of childbearing age with elevation of serum CK should be evaluated for dystrophin mutation. Genetic causes of hyperCKaemia can be pursued with targeted gene sequencing, or whole exome or next generation sequencing. Patients with inherited skeletal muscle diseases may also have associated cardiac disease, so a cardiology evaluation should be considered in all patients with unexplained CK elevations.
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Chinoy, Hector, and Robert G. Cooper. Polymyositis and dermatomyositis. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0124.
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Polymyositis (PM), dermatomyositis (DM), and inclusion body myositis (IBM) form part of the idiopathic inflammatory myopathies (IIM), a heterogeneous group of rare autoimmune diseases characterized by an acquired proximal muscle weakness, raised muscle enzymes (including creatine kinase), inflammatory cell infiltrates in muscle biopsy tissue, electrophysiological abnormalities, and presence of circulating myositis-specific/myositis-associated autoantibodies. The underlying aetiology of IIM is poorly understood, but likely involves interactions between environmental and genetic risk factors. Myositis may also manifest in association with other connective tissue disorders. The predominant clinical presentation of IIM is skeletal muscle weakness, but many extramuscular features can also occur. Access to good neuropathological support is essential in securing an accurate IIM diagnosis and excluding non-inflammatory myopathies, although IBM is often difficult to distinguish from PM. Antibody testing can help define IIM clinical subtypes, including cancer-associated myositis, predict prognosis, and help in optimizing treatment decisions. MRI can be invaluable for differentiating disease activity from damage, and detecting treatment-induced interval changes. Therapeutic effectiveness of new and existing treatments (where the evidence base remains poor) depends on making a prompt diagnosis and initiating early and appropriately aggressive treatment to prevent establishment of muscle damage. This chapter attempts to summarize the salient features of IIM and update the reader about currently used diagnostics and treatment paradigms in this rare and understudied disease.
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Jadon, Deepak R., Tehseen Ahmed, and Ashok K. Bhalla. Disorders of bone mineralization—osteomalacia. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0146.
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Disorders of bone mineralization cause rickets in children and osteomalacia in adults. Both remain common in developing countries. Incidence in Western countries had declined since the fortification of foodstuffs, but appears to be increasing again. Calcium and inorganic phosphate are the key precursors for bone mineralization and growth. The commonest aetiology of osteomalacia is vitamin D deficiency, primarily due to low dietary intake and inadequate sun exposure. In the last decade gene mutations have been identified that are responsible for inherited rickets and osteomalacia, particularly those that result in phosphate deficiency, hypophosphatasia, and vitamin D receptor or metabolizing enzyme mutations. Additionally, the pathogenesis of tumour-induced osteomalacia is becoming better understood. Osteomalacia may present as bone pain and tenderness, muscle pain and weakness, and skeletal deformity or fracture. Key investigations include biochemical assessment and plain radiographs. Radioisotope bone scans and bone biopsy may be considered in selected cases. Differential diagnoses include osteoporosis, seronegative arthritides, and localized soft tissue disorders. Treatment, guided by the underlying aetiology, aims to reduce symptoms, fracture risk, bone deformity and sequelae. Vitamin D deficient patients require vitamin D and calcium replacement.
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Jadon, Deepak R., Tehseen Ahmed, and Ashok K. Bhalla. Disorders of bone mineralization—osteomalacia. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199642489.003.0146_update_001.
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Disorders of bone mineralization cause rickets in children and osteomalacia in adults. Both remain common in developing countries. Incidence in Western countries had declined since the fortification of foodstuffs, but appears to be increasing again. Calcium and inorganic phosphate are the key precursors for bone mineralization and growth. The commonest aetiology of osteomalacia is vitamin D deficiency, primarily due to low dietary intake and inadequate sun exposure. In the last decade gene mutations have been identified that are responsible for inherited rickets and osteomalacia, particularly those that result in phosphate deficiency, hypophosphatasia, and vitamin D receptor or metabolizing enzyme mutations. Additionally, the pathogenesis of tumour-induced osteomalacia is becoming better understood. Osteomalacia may present as bone pain and tenderness, muscle pain and weakness, and skeletal deformity or fracture. Key investigations include biochemical assessment and plain radiographs. Radioisotope bone scans and bone biopsy may be considered in selected cases. Differential diagnoses include osteoporosis, seronegative arthritides, and localized soft tissue disorders. Treatment, guided by the underlying aetiology, aims to reduce symptoms, fracture risk, bone deformity and sequelae. Vitamin D deficient patients require vitamin D and calcium replacement.
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Hall, Andrew, and Shamima Rahman. Mitochondrial diseases and the kidney. Edited by Neil Turner. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0340.
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Mitochondrial disease can affect any organ in the body including the kidney. As increasing numbers of patients with mitochondrial disease are either surviving beyond childhood or being diagnosed in adulthood, it is important for all nephrologists to have some understanding of the common renal complications that can occur in these individuals. Mitochondrial proteins are encoded by either mitochondrial or nuclear DNA (mtDNA and nDNA, respectively); therefore, disease causing mutations may be inherited maternally (mtDNA) or autosomally (nDNA), or can arise spontaneously. The commonest renal phenotype in mitochondrial disease is proximal tubulopathy (Fanconi syndrome in the severest cases); however, as all regions of the nephron can be affected, from the glomerulus to the collecting duct, patients may also present with proteinuria, decreased glomerular filtration rate, nephrotic syndrome, water and electrolyte disorders, and renal tubular acidosis. Understanding of the relationship between underlying genotype and clinical phenotype remains incomplete in mitochondrial disease. Proximal tubulopathy typically occurs in children with severe multisystem disease due to mtDNA deletion or mutations in nDNA affecting mitochondrial function. In contrast, glomerular disease (focal segmental glomerulosclerosis) has been reported more commonly in adults, mainly in association with the m.3243A<G point mutation. Co-enzyme Q10 (CoQ10) deficiency has been particularly associated with podocyte dysfunction and nephrotic syndrome in children. Underlying mitochondrial disease should be considered as a potential cause of unexplained renal dysfunction; clinical clues include lack of response to conventional therapy, abnormal mitochondrial morphology on kidney biopsy, involvement of other organs (e.g. diabetes, cardiomyopathy, and deafness) and a maternal family history, although none of these features are specific. The diagnostic approach involves acquiring tissue (typically skeletal muscle) for histological analysis, mtDNA screening and oxidative phosphorylation (OXPHOS) complex function tests. A number of nDNA mutations causing mitochondrial disease have now been identified and can also be screened for if clinically indicated. Management of mitochondrial disease requires a multidisciplinary approach, and treatment is largely supportive as there are currently very few evidence-based interventions. Electrolyte deficiencies should be corrected in patients with urinary wasting due to tubulopathy, and CoQ10 supplementation may be of benefit in individuals with CoQ10 deficiency. Nephrotic syndrome in mitochondrial disease is not typically responsive to steroid therapy. Transplantation has been performed in patients with end-stage kidney disease; however, immunosuppressive agents such as steroids and tacrolimus should be used with care given the high incidence of diabetes in mitochondrial disease.
Book chapters on the topic "Skeletal muscle biopsy samples"
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Ferguson, Richard A., and Natalie F. Shur. "Skeletal muscle biopsy." In Sport and Exercise Physiology Testing Guidelines, 205–11. 5th ed. London: Routledge, 2022. http://dx.doi.org/10.4324/9781003045267-32.
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Ferguson, Richard A., and Natalie F. Shur. "Skeletal muscle biopsy." In Sport and Exercise Physiology Testing Guidelines: Volume I – Sport Testing, 118–24. 5th ed. London: Routledge, 2022. http://dx.doi.org/10.4324/9781003045281-22.
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Burns, Dennis K. "Skeletal Muscle Biopsy Evaluation." In A Case-Based Guide to Neuromuscular Pathology, 3–48. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-25682-1_1.
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Weidenheim, Karen M. "Optimizing the Skeletal Muscle Biopsy." In Histopathology, 397–410. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1050-2_24.
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Gaspar, Balan Louis, Rakesh Kumar Vasishta, and Bishan Dass Radotra. "A Beginner’s Approach to Skeletal Muscle Biopsy." In Myopathology, 283–84. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-1462-9_16.
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Turner, Daniel C., Andreas M. Kasper, Robert A. Seaborne, Alexander D. Brown, Graeme L. Close, Mark Murphy, Claire E. Stewart, Neil R. W. Martin, and Adam P. Sharples. "Exercising Bioengineered Skeletal Muscle In Vitro: Biopsy to Bioreactor." In Methods in Molecular Biology, 55–79. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-8897-6_5.
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Juel, Carsten. "Membrane Transport in Human Skeletal Muscle." In Muscle Biopsy. InTech, 2012. http://dx.doi.org/10.5772/31425.
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Capel, Frederic, Valentin Barquissau, Ruddy Richard, and Beatrice Morio. "Evaluation of Mitochondrial Functions and Dysfunctions in Muscle Biopsy Samples." In Muscle Biopsy. InTech, 2012. http://dx.doi.org/10.5772/30705.
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Lejay, A., A. L. Charles, J. Zoll, J. Bouitbir, F. Thaveau, F. Piquard, and B. Geny. "Skeletal Muscle Mitochondrial Function in Peripheral Arterial Disease: Usefulness of Muscle Biopsy." In Muscle Biopsy. InTech, 2012. http://dx.doi.org/10.5772/31674.
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Gherardi, Romain, Anthony A. Amato, Hart G. Lidov, and Umberto De Girolami. "Pathology of Skeletal Muscle." In Escourolle and Poirier's Manual of Basic Neuropathology, 299–340. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190675011.003.0012.
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This chapter describes and illustrates the pathology of skeletal muscle as evaluated on muscle biopsy. After an introduction to processing techiques and the normal appearance of skeletal muscle, the basic pathologic reactions in muscle disease are described. The different categories of muscular disorders are subsequently considered and their specific morphological and eventually genetic features underlined. Involvement of the muscle secondary to denervation (neurogenic atrophies) or to neuromuscular transmission defects are first presented, followed by an account of the primary myopathies. Genetically determined diseases of skeletal muscle include muscular dystrophies, congenital myopathies, myofibrillar myopathies, and metabolic myopathies. Inflammatory myopathies may be divided into two groups, depending on whether the causative agent is a known microorganism or if the inflammatory process is believed to be an autoimmune phenomenon.
Conference papers on the topic "Skeletal muscle biopsy samples"
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Jalal, M., JA Campbell, J. Wadsley, and AD Hopper. "OWE-29 Can digital skeletal muscle index predict palliative chemotherapy uptake before patients undergo endoscopic pancreatic biopsy?" In British Society of Gastroenterology Annual Meeting, 17–20 June 2019, Abstracts. BMJ Publishing Group Ltd and British Society of Gastroenterology, 2019. http://dx.doi.org/10.1136/gutjnl-2019-bsgabstracts.289.
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Perez, Matheus Moreira, David Feder, Beatriz da Costa Aguiar Alves, Fernando Luiz Affonso Fonseca, and Alzira Alves de Siqueira Carvalho. "myoMIR and gene expression in myofibrillar myopathy." In XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.662.
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Background: Myofibrillar myopathies (MFM) represent a heterogeneous group of muscle disorders caused by mutations in different genes. It has been identified a group of microRNAs present in muscles named myoMIR. Objective: Evaluate the diagnostic value of these myoMIRs and mRNA expression in skeletal tissue from muscle biopsy of patients with MFM. Design and Setting: Muscle biopsies from 16 MFM patients with mutations in Desmin (DES), Myotilin (MYOT), ZASP, or Filamin C (FLNC) genes, and 18 donors (patients with minimal non- specific changes in muscle biopsy) were included. Study were conducted at FMABC. Methods: mRNA and myoMIR expression from both groups were assessed. The target myoMIRs were MIR1, MIR133a, MIR133b, MIR206, MIR208a, MIR208b, MIR486, and MIR499. Anova and Student’s t-test were performed. Results: Six patients presented mutations in DES, five in ZASP, three in FLNC, and two in MYOT. MIR133b (p=0.05), MIR499 (p=0.027), and mRNA expression was up-regulated in patients with MFM. MIR208a (p=0.042) was higher in the control group. We found an association between MIR133a and the presence of mutations in all genes studied (p=0.006). A relation between MIR486 and mutations in ZASP and DES (p=0.035) was also noted. Conclusions: • MIR208a seems to have a protective function in the muscle fiber; • Heterogeneity could be related to the concentration of gene expression in each patient; • Expression of myoMIRs influences several aspects in the muscle function through genes modulation which are important to myogenesis control;
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Athayde, Natália Merten, and Alzira Alves de Siqueira Carvalho. "The heart of myofibrillary myopathy." In XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.457.
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Context: Myofibrillar myopathies (MFM) represent a heterogeneous group of disorders of skeletal and cardiac muscle caused by mutations in genes that encode proteins of sarcomere. Diagnosis is a challenge due to clinical and genetic variability. Case report: Woman, 36 years old, presenting stumbles and falls for 3 years evolving with proximal limb weakness. At age 30, she fainted and a cardiac pacemaker was implanted. Non-consanguineous parents. Neurological exam: proximal and distal weakness in lower limbs and distal atrophy; osteotendinous reflexes normal. Bilateral scapula alata. Exams: CPK = 457 U / l; EMG: myopathic pattern. Muscle MRI: diffuse and heterogeneous fatty degeneration, marked in sartorius, gracilis and semitedinous. Panel NGS myopathies: pathogenic variant, c.1175T> C, missense in heterozygosis in desmin gene. CONCLUSION: The diagnosis of MFM is based on the morphological findings of muscle biopsy with the presence of protein aggregates as a determining factor. Currently, genetic testing by NGS has facilitated early diagnosis allowing for a more appropriate clinical approach. The desmin gene was the first one described to be associated with this group of myopathies. It encodes the desmin protein, a member of the intermediate filament family present in cardiac and skeletal muscle. Several phenotypes are related to desmin gene: isolated dilated cardiomyopathy; scapuloperoneal weakness and distoproximal weakness with cardiac alterations. Desminopathy is a rare cause of cardiomyopathy and / or myopathy. The diagnosis should be thought in patient with muscle weakness and cardiac changes.
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Ahmed, Amira, Huda Farah, Omnia Ahmed, Dina Elsayegh, Abdelrahman Elgamal, and Nasser Moustafa Rizk. "Profile Of Oxidative Stress Genes In Response To Obesity Treatment." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2021. http://dx.doi.org/10.29117/quarfe.2021.0150.
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Background: Oxidative stress (OS) is an imbalance between free radical production and the antioxidants defense in the body. Previous studies demonstrated the correlation of OS to the increased risk of developing metabolic disorders such as obesity. Sulforaphane (SFN), a bioactive compound, can protect against inflammation and OS, thus an effective anti-obesity supplement. Aim: This study explores the impact of SNF on OS in diet induced obese (DIO) mice via profiling of OS genes and pathways in skeletal muscles related to the anti-obesity effect. Methods: Wild-type CD1 male mice and the knockout of nuclear factor (erythroid-derived 2) like 2 (NrF2) mice were fed a high-fat diet (HFD) for 16 weeks; to induce obesity. Subsequently, each group was subdivided into two subgroups and received either Vehicle (25μl) or SFN (5 mg/kg BW) for four weeks. Body weight was measured daily, and a glucose tolerance test (GTT) was performed after 21 days of treatment. Afterward, mice were decapitated, blood and tissue samples were collected and snap-frozen immediately. Total RNA was extracted from Skeletal muscle and epididymal white adipose tissue (eWAT), leptin expression was measured in (eWAT), and 84 OS genes in skeletal muscle were examined using RT-PCR. Results: Significant reduction in body weight in SFN treated WT mice, while no change in KO mice. Plasma glucose, leptin, and leptin gene expression (eWAT) were significantly reduced in the WT-DIO SFN treated group, while no changes were detected in KO mice. SFN decreases OS damage in skeletal muscles, such as lipid peroxidation and production of reactive oxygen species (ROS). Conclusion: This study demonstrated that SFN had lowered body weight in WT-DIO mice by decreasing OS damage in skeletal muscles through the NrF2 pathway and can be a potential anti-obesity drug.