| 1. |
- Folkesson, Mattias, 1972-, et al.
(author)
-
The expression of heat shock protein in human skeletal muscle : effects of muscle fibre phenotype and training background
- 2013
-
In: Acta Physiologica. - : Wiley-Blackwell. - 1748-1708 .- 1748-1716. ; 209:1, s. 26-33
-
Journal article (peer-reviewed)abstract
- Aim: Exercise-induced adaptations of skeletal muscle are related to training mode and can be muscle fibre type specific. This study aimed to investigate heat shock protein expression in type I and type II muscle fibres in resting skeletal muscle of subjects with different training backgrounds.Methods: Three groups of subjects were included: healthy active not engaged in any training programme (ACT, n = 12), resistance trained (RES, n = 6) and endurance trained (END, n = 8). Biopsies were obtained from vastus lateralis, and immunohistochemistry was performed using monoclonal antibodies against myosin heavy chain I and IIA, αB-crystallin, HSP27, HSP60 and HSP70.Results: In ACT and RES, but not in END, a fibre type–specific expression with higher staining intensity in type I than type II fibres was seen for αB-crystallin. The opposite (II > I) was found for HSP27 in subjects from ACT (6 of 12 subjects) and RES (3 of 6), whereas all subjects from END displayed uniform staining. HSP60 showed no fibre-specific expression. HSP70 displayed a fibre-specific expression pattern (I > II) in ACT (4 of 12), but not in END or RES.Conclusion: This study shows that the level of expression of the different HSPs in human skeletal muscle is influenced by muscle fibre phenotype. The fibre type–specific expression of HSP70 is influenced by resistance and endurance training, whereas those of αB-crystallin and HSP27 is influenced only by endurance training, suggesting the existence of a training-modality-specific action on the adaptive processes including heat shock proteins in human skeletal muscle.
|
|
| 2. |
- Mackey, Abigail L., et al.
(author)
-
The influence of anti-inflammatory medication on exercise-induced myogenic precursor cell responses in humans
- 2007
-
In: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 103:2, s. 425-431
-
Journal article (peer-reviewed)abstract
- The consumption of nonsteroidal anti-inflammatory drugs (NSAIDs) is widespread among athletes when faced with muscle soreness or injury, but the effects of NSAIDs on satellite cell activity in humans are unknown. To investigate this, 14 healthy male endurance athletes (mean peak oxygen consumption 62 ml x kg(-1) x min(-1)) volunteered for the study, which involved running 36 km. They were divided into two groups and received either 100 mg indomethacin per day or placebo. Muscle biopsies collected before the run and on days 1, 3, and 8 afterward were analyzed for satellite cells by immunohistochemistry with the aid of neural cell adhesion molecule (NCAM) and fetal antigen-1 (FA1) antibodies. Muscle biopsies were also collected from untrained individuals for comparison. Compared with preexercise levels, a 27% increase in the number of NCAM+ cells was observed on day 8 postexercise in the placebo group (P < 0.05), while levels remained similar at all time points in the NSAID group. No change was seen in the proportion of FA1+ cells, although lower levels were found in the muscle of endurance-trained athletes compared with untrained individuals (P < 0.05). These results suggest that ingestion of anti-inflammatory drugs attenuates the exercise-induced increase in satellite cell number, supporting the role of the cyclooxygenase pathway in satellite cell activity.
|
|
| 3. |
- Nielsen, Rasmus Oestergaard, et al.
(author)
-
Collagen content in the vastus lateralis and the soleus muscle following a 90-day bed rest period with or without resistance exercises
- 2015
-
In: MLTJ - Muscles Ligaments and Tendons Journal. - : Edra SpA. - 2240-4554. ; 5:4, s. 305-309
-
Journal article (peer-reviewed)abstract
- Introduction: spaceflight seems associated with deterioration of the function of the skeletal muscles. Since muscle collagen is critical for muscle function, an improved understanding of the content of the muscle collagen during long-term inactivity seems important. Bed-rest with in-bed resistance training serves as a proxy for the conditions in space. Therefore, ground-based studies may improve the understanding of the consequences of long-term inactivity.Purpose: the purpose is to compare the change in collagen protein in the vastus lateralis (VL) and the soleus (SOL) muscle amongst persons exposed to a 90-day bed rest with or without resistance exercise.Methods: an explorative analysis was completed based on data from a randomized, controlled trial.The intervention group (BRE, SOL n=4, VL n=8) performed supine-based squat exercises, whereas the controls (BE, SOL n=6, VL n=12) remained inactive during follow-up. Muscle biopsies from vastus lateralis and soleus were taken at baseline(pre) and after 90-days’ follow-up (post). Muscle collagen (μg collagen/mg protein) was quantified. Two-way repeated measurements ANOVA was used to compare the interaction between the intervention (BRE/BR) and time (pre/post) for each muscle.Results: the collagen content of VL was similar between pre and post in the BRE group (-3.8 μg collagen/mg protein [95% CI: -22.0; 14.4], p=0.68) while it rose amongst individuals in the BR group (14.9 μg collagen/mg protein [95% CI: -0.01; 29.7], p=0.05). The difference of 18.66 [95% CI: -6.5; 43.9] between BRE and BR across time was, however, not significant (p=0.14). No significant reduction in SOL muscle collagen content was observed from pre to post in the BR group (-9.3 μg collagen/mg protein [95% CI: -24.9; 6.4], p=0.25) or in the BRE group (-6.5 μg collagen/mg protein [95% CI: -25.6; 12.6], p=0.50). There was no difference in the effect of BR versus BRE over time (mean difference -2.78 μg collagen/mg protein[95% CI: -29.7; 24.1], p=0.82).Conclusion: muscle collagen content in the VL or SOL muscle does not seem to differ after a 90-day bed rest period with or without squat exercises.
|
|
| 4. |
- Ponsot, Elodie, 1973-, et al.
(author)
-
Telomere length of anterior crucial ligament after rupture : similar telomere length in injured and noninjured ACL portions
- 2011
-
In: Journal of Orthopaedic Research. - : John Wiley & Sons. - 0736-0266 .- 1554-527X. ; 29:1, s. 79-83
-
Journal article (peer-reviewed)abstract
- The regeneration of ligaments following injury is a slow process compared to the healing of many other tissues and the underlying mechanisms remain unknown. The purpose of the study was to evaluate the proliferative potential of ligaments by assessing telomere length within three distinct parts of human anterior cruciate ligament (ACL) obtained during ACL reconstruction: the macroscopically injured proximal part and macroscopically noninjured mid- and distal portions in eight subjects (age 28 +/- 8 years). The mean telomere length in ACL was within normal range of values usually reported for other tissues indicating that the endogenous machinery responsible for the proliferative potential of ligament is not implicated in its poor healing capacity. The three ACL parts showed similar mean TRF lengths (distal part: 11.5 +/- 0.8 kbp, mid-portion: 11.8 +/- 1.2 kbp, proximal part: 11.9 +/- 1.6 kbp) and there was no relationship between mean telomere length in ACL and the healing duration after rupture. This implies that despite the occurrence of ligament repair including a phase of intense cell proliferation the proliferative potential of ruptured ACL is not impaired. This knowledge is important for scientists and clinicians aiming to understand the mechanisms behind the low healing capacity of ligament.
|
|
| 5. |
- Rosendal, Lars, et al.
(author)
-
Increase in interstitial interleukin-6 of human skeletal muscle with repetitive low-force exercise
- 2005
-
In: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 98:2, s. 477-481
-
Journal article (peer-reviewed)abstract
- Interleukin (IL)-6, which is released from muscle tissue during intense exercise, possesses important metabolic and probably anti-inflammatory properties. To evaluate the IL-6 response to low-intensity exercise, we conducted two studies: 1) a control study with insertion of microdialysis catheters in muscle and determination of interstitial muscle IL-6 response over 2 h of rest and 2) an exercise study to investigate the IL-6 response to 20 min of repetitive low-force exercise. In both studies, a microdialysis catheter (cutoff: 3,000 kDa) was inserted into the upper trapezius muscle of six male subjects, and the catheters were perfused with Ringer-acetate at 5 mul/min. Venous plasma samples were taken in the exercise study. The insertion of microdialysis catheters into muscle resulted in an increase in IL-6 from 8 +/- 0 to 359 +/- 171 and 484 +/- 202 pg/ml after 65 and 110 min, respectively (P less than 0.001). Similarly, in the exercise study, IL-6 increased to 289 +/- 128 pg/ml after a 55-min rest (P less than 0.001). During the subsequent repetitive low-force exercise, muscle IL-6 further increased to 1,246 +/- 461 pg/ml and reached 2,132 +/- 477 pg/ml after a 30-min recovery ( all P less than 0.001). In contrast to this, plasma IL-6 did not significantly change in response to exercise. We conclude that upper extremity, low-intensity exercise results in a substantial increase in IL-6 in the interstitium of the stabilizing trapezius muscle, whereas no change is seen for plasma IL-6.
|
|
| 6. |
- Spörndly-Nees, Søren, et al.
(author)
-
The navicular position test - a reliable measure of the navicular bone position during rest and loading.
- 2011
-
In: International journal of sports physical therapy. - 2159-2896. ; 6:3, s. 199-205
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Lower limb injuries are a large problem in athletes. However, there is a paucity of knowledge on the relationship between alignment of the medial longitudinal arch (MLA) of the foot and development of such injuries. A reliable and valid test to quantify foot type is needed to be able to investigate the relationship between arch type and injury likelihood. Feiss Line is a valid clinical measure of the MLA. However, no study has investigated the reliability of the test.OBJECTIVES: The purpose was to describe a modified version of the Feiss Line test and to determine the intra- and inter-tester reliability of this new foot alignment test. To emphasize the purpose of the modified test, the authors have named it The Navicular Position Test.METHODS: Intra- and inter-tester reliability were evaluated of The Navicular Position Test with the use of ICC (interclass correlation coefficient) and Bland-Altman limits of agreement on 43 healthy, young, subjects.RESULTS: Inter-tester mean difference -0.35 degrees [-1.32; 0.62] p = 0.47. Bland-Altman limits of agreement -6.55 to 5.85 degrees, ICC = 0.94. Intra-tester mean difference 0.47 degrees [-0.57; 1.50] p = 0.37. Bland-Altman limits of agreement -6.15 to 7.08 degrees, ICC = 0.91.DISCUSSION: The present data support The Navicular Position Test as a reliable test of the navicular bone position during rest and loading measured in a simple test set-up.CONCLUSION: The Navicular Position Test was shown to have a high intraday-, intra- and inter-tester reliability. When cut off values to categorize the MLA into planus, rectus, or cavus feet, has been determined and presented, the test could be used in prospective observational studies investigating the role of the arch type on the development of various lower limb injuries.
|
|
