| 1. |
- Boman, Niklas, et al.
(författare)
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Gene expression and fiber type variations in repeated vastus lateralis biopsies
- 2015
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 52:2, s. 812-817
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Muscle sample collection can introduce variation in any measured variable due to inter- and intramuscle variation. We investigated the variation in gene expression and fiber type composition after repeated biopsy sampling from the vastus lateralis muscle. Methods: Six subjects donated 3 tissue samples each. One hour after baseline sampling from 1 vastus lateralis muscle, samples from both vastus lateralis muscles were obtained. Results: The fiber type composition differed between biopsies taken from the same leg. There were no within-subject differences in gene expression between the 3 biopsies. Multivariate analysis supports a model in which gene expression differs significantly between individuals but is not affected by repeated muscle biopsy sampling from the same subject. Conclusion: One vastus lateralis muscle sample per subject is sufficient to establish a reliable baseline for comparing gene expression representing selected pathways over time within the same individual.
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| 2. |
- Edmundsson, David S., et al.
(författare)
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Muscle changes in patients with diabetes and chronic exertional compartment syndrome before and after treatment with fasciotomy
- 2018
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Ingår i: Muscle and Nerve. - : John Wiley & Sons. - 0148-639X .- 1097-4598. ; 57:2, s. 229-239
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Muscle changes in patients with diabetes and lower leg pain due to chronic exertional compartment syndrome (CECS) were investigated before and after fasciotomy.Methods: The tibialis anterior muscle was analyzed with histochemical and morphological techniques in 7 patients with diabetes and CECS before fasciotomy and in 5 of them 1 year after fasciotomy. Nondiabetic patients with CECS and healthy participants served as references.Results: Before treatment, walking distance until occurrence of pain was limited (<0.2 km). Intramuscular pressure was significantly higher than in reference participants. Muscle analysis showed changes pathognomonic for neuropathy and myopathy and a restricted capillary network, with significantly more severe changes in the muscles of patients with diabetes than in the muscles of nondiabetic patients. Treatment with fasciotomy improved clinical signs, increased walking ability, and reduced muscle abnormalities, but muscle capillarization remained low.Discussion: Patients with diabetes and CECS have distinct pathological changes in affected muscles. Pressure-relieving fasciotomy triggers a regenerative response in the muscle tissue but not in the capillary bed.
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| 3. |
- El-Habta, Roine, et al.
(författare)
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Adipose stem cells enhance myoblast proliferation via acetylcholine and extracellular signal-regulated kinase 1/2 signaling
- 2018
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Ingår i: Muscle and Nerve. - : WILEY. - 0148-639X .- 1097-4598. ; 57:2, s. 305-311
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In this study we investigated the interaction between adipose tissue-derived stem cells (ASCs) and myoblasts in co-culture experiments. Methods: Specific inductive media were used to differentiate ASCs in vitro into a Schwann cell-like phenotype (differentiated adipose tissuederived stem cells, or dASCs) and, subsequently, the expression of acetylcholine (ACh)-related machinery was determined. In addition, the expression of muscarinic ACh receptors was examined in denervated rat gastrocnemius muscles. Results: In contrast to undifferentiated ASCs, dASCs expressed more choline acetyltransferase and vesicular acetylcholine transporter. When co-cultured with myoblasts, dASCs enhanced the proliferation rate, as did ACh administration alone. Western blotting and pharmacological inhibitor studies showed that phosphorylated extracellular signal-regulated kinase 1/2 signaling mediated these effects. In addition, denervated muscle showed higher expression of muscarinic ACh receptors than control muscle. Discussion: Our findings suggest that dASCs promote proliferation of myoblasts through paracrine secretion of ACh, which could explain some of their regenerative capacity in vivo.
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| 4. |
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| 5. |
- Jergovic, Davor, 1959-, et al.
(författare)
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Changes in a rat facial muscle after facial nerve injury and repair
- 2001
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Ingår i: Muscle and Nerve. - : John Wiley & Sons. - 0148-639X .- 1097-4598. ; 24:9, s. 1202-1212
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Tidskriftsartikel (refereegranskat)abstract
- This study describes changes in a rat facial muscle innervated by the mandibular and buccal facial nerve branches 4 months after nerve injury and repair. The following groups were studied: (A) normal controls; (B) spontaneous reinnervation by collateral or terminal sprouting; (C) reinnervation after surgical repair of the mandibular branch; and (D) chronic denervation. The normal muscle contained 1200 exclusively fast fibers, mainly myosin heavy chain (MyHC) IIB fibers. In group B, fiber number and fiber type proportions were normal. In group C, fiber number was subnormal. Diameters and proportions of MyHC IIA and hybrid fibers were above normal. The proportion of MyHC IIB fibers was subnormal. Immediate and delayed repair gave similar results with respect to the parameters examined. Group D rats underwent severe atrophic and degenerative changes. Hybrid fibers prevailed. These data suggest that spontaneous regeneration of the rat facial nerve is superior to regeneration after surgical repair and that immediacy does not give better results than moderate delay with respect to surgical repair. Long delays are shown to be detrimental.
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| 6. |
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| 7. |
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| 8. |
- Schaakxs, Dominique, et al.
(författare)
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Regenerative cell injection in denervated muscle reduces atrophy and enhances recovery following nerve repair
- 2013
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 47:5, s. 691-701
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Functional muscle recovery after peripheral nerve injury is far from optimal, partly due to atrophy of the muscle arising from prolonged denervation. We hypothesized that injecting regenerative cells into denervated muscle would reduce this atrophy. Methods: A rat sciatic nerve lesion was performed, and Schwann cells or adipose-derived stem cells, untreated or induced to a Schwann-celllike phenotype (dASC), were injected into the gastrocnemius muscle. Nerves were either repaired immediately or capped to prevent muscle reinnervation. One month later, functionality was measured using a walking track test, and muscle atrophy was assessed by examining muscle weight and histology. Results: Schwann cells and dASC groups showed significantly better scores on functional tests when compared with injections of growth medium alone. Muscle weight and histology were also significantly improved in these groups. Conclusion: Cell injections may reduce muscle atrophy and could benefit nerve injury patients.
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| 9. |
- Stewart, H G, et al.
(författare)
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Clinicopathological phenotype of ALS with a novel G72C SOD1 gene mutation mimicking a myopathy.
- 2006
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 33:5, s. 701-706
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Tidskriftsartikel (refereegranskat)abstract
- A 71-year-old woman with a family history of amyotrophic lateral sclerosis (ALS) was investigated for symmetrical, proximal limb and abdominal muscle weakness. Initial examination showed mild proximal muscle weakness in the arms and legs, slightly elevated serum creatine kinase (CK) level, and normal electromyographic (EMG) findings. A myopathy was the presumed diagnosis. Over the next year, weakness became severe and tendon reflexes became unelicitable; no upper motor signs were present. EMG then showed acute and chronic denervation and a muscle biopsy showed target fibers and grouped atrophy. DNA analysis revealed a G72C CuZn-superoxide dismutase (SOD1) mutation. Fasciculations were absent throughout the disease. The patient died 53 months after symptom onset and autopsy revealed loss of lower motor neurons (LMN) and SOD1-positive inclusions. This case expands the phenotypic spectrum of ALS associated with SOD1 mutations to include presenting features that mimic a myopathy.
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| 10. |
- Strigård, Karin, et al.
(författare)
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T-lymphocyte subsets, functional deficits, and morphology in sciatic nerves during experimental allergic neuritis
- 1987
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Ingår i: Muscle and Nerve. - New York : John Wiley & Sons. - 0148-639X .- 1097-4598. ; 10:4, s. 329-337
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Tidskriftsartikel (refereegranskat)abstract
- Conduction velocities, demyelination, "macrophage/dendritic" cells, different sets of T-lymphocytes, and immunoglobulins were estimated in sciatic nerves during various phases of experimental allergic neuritis in Lewis rats. Demyelination was minimal day 15 postimmunization (p.i.) when conduction velocity already was reduced, somewhat more pronounced day 17 p.i. when nerve conduction was blocked, and most pronounced day 23 p.i. when nerve conduction partially had recovered. This suggests a dissociation between the degree of demyelination and the functional deficits. Decrease of sciatic nerve conduction velocities coincided with endoneurial appearance of T-lymphocytes and "macrophage/dendritic" cells, as well as endoneurial immunoglobulins, day 15 p.i. Later partial functional recovery occurred in parallel with the disappearance of T-cells. The degree of functional deficits thus correlated with the number of endoneurial T-lymphocytes. T-cells may, directly or indirectly, initiate several of the disease components in experimental allergic neuritis, including the nerve conduction deficit.
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