| 1. |
- Mackey, A. L., et al.
(författare)
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Assessment of satellite cell number and activity status in human skeletal muscle biopsies
- 2009
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Ingår i: Muscle and Nerve. - : John Wiley & Sons. - 0148-639X .- 1097-4598. ; 40:3, s. 455-465
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Tidskriftsartikel (refereegranskat)abstract
- The primary aim of our study was to validate the assessment of myonuclear and satellite cell number in biopsies from human skeletal muscle. We found that 25 type I and 25 type II fibers are sufficient to estimate the mean number of myonuclei per fiber. In contrast, the assessment of satellite cells improved when more fibers were included. Second, we report that small differences in counting satellite cells using CD56 and Pax7 antibodies can be attributed to the different staining profiles. Third, we provide support for the use of Ki67 in evaluating the proportion of active satellite cells. We observed very few (up to 1.3%) active satellite cells in healthy adult skeletal muscle at rest, but they increased significantly (up to 7-fold) following muscle activity. This study provides valuable tools to assess the behavior of satellite cells, both in pathological conditions and in response to physiological stimuli.
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| 2. |
- Ponsot, Elodie, 1973-, et al.
(författare)
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Skeletal muscle telomere length is not impaired in healthy physically active old women and men
- 2008
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 37:4, s. 467-472
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Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that the number of satellite cells is lower in old than young men and women. The aim of this study was to further explore the effects of aging on the regenerative potential of skeletal muscle in 16 young and 26 old men and women with comparable physical activity level (young, 25 +/- 4 years; old, 75 +/- 4 years). Mean and minimum telomere lengths were determined using Southern blot analyses on biopsies obtained from the tibialis anterior muscle. There were no significant age or gender effects on mean and minimal telomeric lengths, suggesting that the replicative potential in the remaining satellite cells in the tibialis anterior muscle is not impaired with increasing age and the existence of in vivo regulatory mechanisms allowing the maintenance of telomere length. These results imply that moderate physical activity regularly performed by old subjects is not associated with accelerated telomere loss.
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| 3. |
- Verney, Julien, et al.
(författare)
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Effects of combined lower body endurance and upper body resistance training on the satellite cell pool in elderly subjects
- 2008
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 38:3, s. 1147-1154
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Tidskriftsartikel (refereegranskat)abstract
- To distinguish the respective potential of endurance and resistance training to increase the satellite cell pool, we investigated the effects of 14 weeks of concurrent lower body endurance and upper body resistance training (3 sessions/week) on vastus lateralis (VLat) and deltoid (Del) muscles of 10 active elderly men. NCAM+ satellite cells and myonuclear number were assessed in VLat and Del. After 14 weeks of training the NCAM+ satellite cell pool increased similarly (+38%) in both muscles, mainly in type II muscle fibers (P < 0.05). There was no significant change in myonuclear number or myonuclear domain in either muscle. Combining resistance training in the upper limbs with endurance training in the lower limbs is an efficient strategy to enhance the satellite cell pool in upper and lower body muscles in elderly subjects. Our results provide a practical reference for the determination of optimal exercise protocols to improve muscle function and regeneration in the elderly.
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| 4. |
- Wåhlin-Larsson, Britta, 1959-, et al.
(författare)
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The expression of vascular endothelial growth factor in skeletal muscle of patients with sleep disorders
- 2009
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Ingår i: Muscle and Nerve. - New York, NY : John Wiley & Sons. - 0148-639X .- 1097-4598. ; 40:4, s. 556-561
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Tidskriftsartikel (refereegranskat)abstract
- An increased capillary network has been observed in the skeletal muscle in patients with Restless Legs Syndrome (RLS) and Obstructive sleep apnea syndrome (OSAS). These changes could be due to upregulation of growth factors responsible for angiogenesis.The aim of the study was to examine the occurrence and localization of VEGF and capillary proliferation in skeletal muscle of RLS (n=12), OSAS (n=12) and controls (n=11).Double-immunofluorescence staining for capillaries (CD31) and VEGF, and proliferating cells (Ki-67), was carried out on biopsies taken from the tibialis anterior. The percentage of capillaries expressing VEGF (CD31,VEGF+) was significantly higher in OSAS and RLS compared to controls. The percentage of proliferating capillaries (CD31,Ki-67+) was significantly higher in OSAS compared with controls.In conclusion our study shows the occurrence of proliferation of endothelial cells in skeletal muscle in RLS and OSAS, supporting an upregulation of VEGF located in capillaries probably due to local hypoxia.
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