Lupa

Iskanje po repozitoriju Pomoč

A- | A+ | Natisni
Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


1 - 10 / 23
Na začetekNa prejšnjo stran123Na naslednjo stranNa konec
1.
Effects of inactivity on human muscle glutathione synthesis by a double-tracer and single-biopsy approach
Francesco Agostini, Luciano Dalla Libera, Joern Rittweger, Sara Mazzucco, Mihaela Jurdana, Igor B. Mekjavić, Rado Pišot, Luisa Gorza, Marco Narici, Gianni Biolo, 2010, izvirni znanstveni članek

Opis: Oxidative stress is often associated to inactivity-mediated skeletal muscle atrophy. Glutathione is one of the major antioxidant system stimulated, both at muscular and systemic level, by activation of oxidative processes. We measured changes in glutathione availability, oxidative stress induction and atrophy extent mediated by 35-days of experimental bed rest in vastus lateralis muscle of healthy human volunteers. To assess muscle glutathione synthesis, we applied a novel single-biopsy and double-tracer ([2H2]glycine and [15N]glycine) approach based on evaluation of steady-state precursor incorporation in product. The correlations between the traditional (multiple-samples, one-tracer) and new (one-sample, double-tracer infusion) methods were analyzed in erythrocytes by Passing & Bablok and Altman-Bland tests. Muscle glutathione absolute synthesis rate increased following bed rest from 5.5 1.1 to 11.0 1.5 mmol (kg wet tissue / day)-1 (n=9; p=0.02) while glutathione concentration failed to change significantly. Bed rest induced vastus lateralis muscle atrophy, as assessed by pennation angle changes measured by ultrasonography (from 18.6 1.0 to 15.3 0.9 degrees; p=0.01) and thickness changes (from 2.3 0.2 to 1.9 0.1 cm; p<0.001). Moreover, bed rest increased protein oxidative stress, as measured by muscle protein carbonylation changes (from 0.6 0.1 to 1.00 0.1 Oxy RP-1; p<0.04). In conclusion, we developed in erythrocytes a new minimally-invasive method to determine peptide synthesis rate in human tissues. Application of the new method to skeletal muscle suggests that disuse atrophy is associated to oxidative stress induction as well as to compensatory activation of the glutathione system
Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: Antioxidant system, Muscle damage, Oxidative stress, bed rest, muscle glutathione, stable isotopes
Objavljeno: 15.10.2013; Ogledov: 2010; Prenosov: 67
URL Polno besedilo (0,00 KB)

2.
Between-day reliability of a method for non-invasive estimation of muscle composition
Boštjan Šimunič, 2012, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: Skeletal muscle, Tensiomyography, repeatability, validity
Objavljeno: 15.10.2013; Ogledov: 1960; Prenosov: 76
URL Polno besedilo (0,00 KB)

3.
4.
Cancer cachexia-anorexia syndrome and skeletal muscle wasting
Mihaela Jurdana, 2009, pregledni znanstveni članek

Opis: Cachexia-anorexia syndrome is a common and important indicator of cancer. It occurs in 30% to 80% of cancer patients. Cachexia means "bad condition" and may be present in the early stages of tumor growth, before any signs of malignancy. Cancer cachexia is a syndrome of progressive body wasting, characterized by loss of adipose tissue and skeletal muscle mass. In most cancer patients, cachexia is characteriyed by anorexia, which implies a failure of food intake, regulated through a complex system of hormones and neuropeptides. A decline in food intake relative to energy expenditure is a fundamental physiologic derangement leading to cancer associated weight loss. The weight loss in patients with cachexia-anorexia syndrome differs from that in caloric starvation or anorexia nervosa. The pathophysiology of cancer cachexia is not fully understood; however, studies have shown that cytokines are important in the alteration of the carbohydrate, lipid and protein metabolism. Cancer, prolonged bed rest, HIV infection and aging are conditionsin which muscle wasting is a common feature. An intervention that may potentially attenuate the progression of muscle wasting in cancer patientsis resistance exercise training, defined as multiple repetitions of static or dynamic muscular contractions that increase muscle mass. The main components of the pathological state of cachexia are anorexia and metabolic abnormalities such as fat depletion and muscle protein catabolism. Future developments may concentrate on the molecular abnormalities of cachexia and on examination of the functional benefit of resistance exercise training for cancer related muscle wasting.
Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: cancer cachexia, muscle wasting, cytokines, muscle
Objavljeno: 15.10.2013; Ogledov: 1980; Prenosov: 51
URL Polno besedilo (0,00 KB)

5.
Neural agrin changes the electrical properties of developing human skeletal muscle cells
Mihaela Jurdana, Guido Fumagalli, Zoran Grubič, Paola Lorenzon, Tomaž Marš, Marina Sciancalepore, 2009, izvirni znanstveni članek

Opis: Recent investigations suggest that the effects of neural agrin might not be limited to neuromuscular junction formation and maintenance and that other aspects of muscle development might be promoted by agrin. Here we tested the hypothesis that agrin induces a change in the excitability properties in primary cultures of non-innervated human myotubes. Electrical membrane properties of human myotubes were recorded using the whole-cell patch-clamp technique. Cell incubation with recombinant chick neural agrin (1 nM) led to amore negative membrane resting potential. Addition of strophanthidin, a blocker of the Na(+)žK(+) ATPase, depolarized agrin-treated myotubes stronger than control, indicating, in the presence of agrin, a higher contribution of the Na(+)žK(+) ATPase in establishing the resting membrane potential. Indeed, larger amounts of both the alpha1 and the alpha2 isoforms of the Na(+)žK(+) ATPase protein were expressed in agrin-treated cells. A slight but significantdown-regulation of functional apamin-sensitive K(+) channels was observed after agrin treatment. These results indicate that neural agrin mightact as a trophic factor promoting the maturation of membrane electrical properties during differentiation, confirming the role of agrin as a general promoter of muscle development.
Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: agrin, myogenesis, electrical membrane properties, skeletal muscle, Na+/K+ pump
Objavljeno: 15.10.2013; Ogledov: 1537; Prenosov: 67
URL Polno besedilo (0,00 KB)
Gradivo ima več datotek! Več...

6.
Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training
Desy Salvadego, R. Domenis, Stefano Lazzer, Simone Porcelli, Joern Rittweger, Giovanna Rizzo, I. Mavelli, Boštjan Šimunič, Rado Pišot, Bruno Grassi, 2013, izvirni znanstveni članek

Opis: Oxidative function during exercise was evaluated in 11 young athletes with marked skeletal muscle hypertrophy induced by long-term resistance training (RTA, body mass 102.67.3 kg, meanSD) and 11 controls (CTRL, body mass 77.86.0). Pulmonary O2 uptake (V'O2) and vastus lateralis muscle fractional O2 extraction (by near-infrared spectroscopy) were determined during an incremental cycle ergometer (CE) and one-leg knee-extension (KE) exercise. Mitochondrial respiration was evaluated ex vivo by high-resolution respirometry in permeabilized vastus lateralis fibers obtained by biopsy. Quadriceps femoris muscle cross sectional area, volume (determined by magnetic resonance imaging) and strength were greater in RTA vs. CTRL (by ~40%, ~33% and ~20%, respectively). V'O2peak during CE was higher in RTA vs. CTRL (4.050.64 L min-1 vs. 3.560.30); no difference between groups was observed during KE. The O2 cost of CE exercise was not different between groups. When divided per muscle mass (for CE) or quadriceps muscle mass (for KE) V'O2peak was lower (by 15-20%) in RTA vs. CTRL. Vastus lateralis fractional O2 extraction was lower in RTA vs. CTRL at all work rates, both during CE and KE. RTA had higher ADP-stimulated mitochondrial respiration (56.723.7 pmolO2s-1mg-1 ww) vs. CTRL (35.710.2), and a tighter coupling of oxidative phosphorylation. In RTA the greater muscle mass and maximal force, and the enhanced mitochondrial respiration seem to compensate for the hypertrophy-induced impaired peripheral O2 diffusion. The net results are an enhanced whole body oxidative function at peak exercise, and unchanged efficiency and O2 cost at submaximal exercise, despite a much greater body mass
Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: skeletal muscle, hypertrophy, mitochondrial respiration, oxidative metabolism, exercise
Objavljeno: 15.10.2013; Ogledov: 1967; Prenosov: 51
URL Polno besedilo (0,00 KB)

7.
Whole muscle contractile parameters and thickness loss during 35-day bed rest
Rado Pišot, Marco Narici, Boštjan Šimunič, Maarten D. de Boer, Olivier Seynnes, Mihaela Jurdana, Gianni Biolo, Igor B. Mekjavić, 2008, izvirni znanstveni članek

Opis: Extended exposure to microgravity leads to significant musculoskeletal adaptations. Contractile parameters of four skeletal muscles (biceps brachii-BB, vastus medialis-VM, biceps femoris-BF and gastrocnemius medialis-GM) were measured in ten healthy males (aged 22.3 +/- 2.2 years) during 35 days of horizontal bed rest by a mechanomyography-based method termed 'tensiomyography' (TMG). Two contractile parameters: contraction time (Tc) and maximal displacement (Dm) were individually measured from electrically evoked maximal single twitch TMG response of all four muscles before and after bed rest. Significant changes in Tc were found after bed rest, as shown by an increase in GM muscle Tc by 18% (p < 0.01). Dm values significantly increased (p < 0.01) after bed rest, by 24, 26 and 30% in the VM, BF and GM muscles, respectively. In the GM, the change in Dm significantly correlated with the decrease in muscle thickness (r = -0.70, p < 0.01). In conclusion, bed rest induced changes in both Dm and Tc of the TMG signal; changes in Dm being inversely related to those of muscle thickness. Amongst the investigated muscles, most affected, in terms of atrophy and mechanical alterations, were those of the lower limbs. The observed increase in Dm may be attributed to a decrease in muscle, as well as tendon stiffness, causing larger muscle fibre and non-contractile tissue oscillations following contraction.
Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: Bed rest, skeletal muscle, muscle contraction, muscle thickness, mechanomyography, tensiomiography, ultrasound
Objavljeno: 15.10.2013; Ogledov: 2110; Prenosov: 60
URL Polno besedilo (0,00 KB)
Gradivo ima več datotek! Več...

8.
Validity of measuring muscle activation levels by isokinetic testing
Romina Umer, Mitja Gerževič, Vojko Strojnik, 2011, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: muscle activation, strength deficit, isokinetic dynamometer, interpolated twitch, electrical stimulation
Objavljeno: 15.10.2013; Ogledov: 1697; Prenosov: 22
URL Polno besedilo (0,00 KB)

9.
Effect of 5 weeks horizontal bed rest on human muscle thickness and architecture of weight bearing and non-weight bearing muscles
Maarten D. de Boer, Olivier Seynnes, Pietro di Prampero, Rado Pišot, Igor B. Mekjavić, Gianni Biolo, Marco Narici, 2008, izvirni znanstveni članek

Opis: The aim of the present study was to investigate the changes in thickness, fascicle length (L f) and pennation angle of the antigravity gastrocnemiusmedialis (GM) and vastus lateralis (VL) muscles, and the non-antigravity tibialis anterior (TA) and biceps brachii (BB) muscles measured by ultrasonography in ten healthy males (aged 22.3 +/- 2.2 years) in response to 5 weeks of horizontal bed rest (BR). After BR, muscle thickness decreased by 12.2 +/- 8.8% (P < 0.05) and 8.0 +/- 9.1% (P < 0.005) in the GM and VL, respectively. No changes were observed in the TA and BB muscles. L f and pennation angle decreased by 4.8 +/- 5.0% (P < 0.05) and 14.3 +/- 6.8% (P < 0.005) in the GM and by 5.9 +/- 5.3% (P < 0.05) and 13.5 +/- 16.2% (P < 0.005) in the VL, again without any changes in the TA and BB muscles. The finding that amongst the antigravity muscles of the lower limbs, the GM deteriorated to a greater extent than the VL is possibly related to the differences in relative load that this muscle normally experiences during daily loading. The dissimilar response in antigravity and non-antigravity muscles to unloading likely reflects differences in loading under normal conditions. The significant structural alterations of the GM and VL muscles highlight the rapid remodelling of muscle architecture occurring with disuse.
Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: muscle, disuse, microgravity, atrophy
Objavljeno: 15.10.2013; Ogledov: 2016; Prenosov: 62
URL Polno besedilo (0,00 KB)
Gradivo ima več datotek! Več...

10.
Costamere remodeling with muscle loading and unloading in healthy young men
Ruowei Li, Marco V. Narici, Robert M. Erskine, Olivier Seynnes, Joern Rittweger, Rado Pišot, Boštjan Šimunič, M. Flück, 2013, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: Zadetek v naslovu
Ključne besede: costamere, atrophy, focal adhesion kinase, hypertrophy, physical inactivity, bed rest, skeletal muscle, myofibril, vinculin
Objavljeno: 15.10.2013; Ogledov: 1763; Prenosov: 64
URL Polno besedilo (0,00 KB)

Iskanje izvedeno v 0 sek.
Na vrh
Logotipi partnerjev Univerza v Mariboru Univerza v Ljubljani Univerza na Primorskem Univerza v Novi Gorici