| 1. |
- Barreto Henriksson, Helena, et al.
(författare)
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Support of Concept that Migrating Progenitor Cells from Stem Cell Niches Contribute to Normal Regeneration of the Adult Mammal Intervertebral Disc: A Descriptive study in the New Zeeland white Rabbit.
- 2012
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Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 37:9, s. 722-732
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Study Design. Descriptive experimental study performed in rabbits of two age groups.Objective. To study and investigate presence of prechondrocytic cells and cell migration routes in the IVD region, to gain knowledge about the normal IVD regeneration pattern.Summary of Background Data. Disc degeneration is believed to play a major role in patients with chronic lumbar pain. Regeneration processes and cell migration within the intervertebral disc (IVD) have been sparsely described. Therefore it is of interest to increase knowledge of these processes in order to understand pathological conditions of the IVD.Methods. 5-bromo-2-deoxyuridine (BrdU) in vivo labelling was performed in two groups of rabbits, 3 and 9 months old at the beginning of the experiment, in total 27 rabbits. BrdU is incorporated into DNA during mitosis and then it is gradually diluted with each cell division until it finally disappears. Incorporation of BrdU was then visualized by immunohistochemistry (IHC) at different time points providing cell division pattern and presence of slow-cycling cells in the IVD region. IVD tissue was investigated by IHC for: Growth- and differentiation-factor-5 (GDF5), SOX9 (chondrogenic lineage markers), SNAIL homolog1 (SNAI1), SNAIL homolog2 (SLUG)(migration markers) and β1-INTEGRIN (cellular adhesion marker). In addition, GDF5, SOX9 and BMPRIB expression were investigated on genetic level.Results. BrdU+ cells were observed in early time points in the IVD niche, adjacent to the epiphyseal plate, at later time points mainly in outer region of the annulus fibrosus (AF) for both age groups of rabbits, indicating a gradual migration of cells. The presence of SLUG, SNAI1, GDF5, SOX9 and β1-INTEGRIN were found in same regions.Conclusion. The results suggest a cellular migration route from the IVD stem cell niche toward the AF and the inner parts of the IVD. These findings may be of importance for understanding IVD regenerative mechanisms and for future development of biological treatment strategies.
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| 2. |
- Bergknut, Niklas, et al.
(författare)
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The Dog as an Animal Model for Intervertebral Disc Degeneration?
- 2012
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Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 37, s. 351-358
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. Prospective observational and analytic study.Objective. To investigate whether spontaneous intervertebral disc degeneration (IVDD) occurring in both chondrodystrophic (CD) and nonchondrodystrophic dogs (NCD) can be used as a valid translational model for human IVDD research.Summary of Background Data. Different animal models are used in IVDD research, but in most of these models IVDD is induced manually or chemically rather than occurring spontaneously.Methods. A total of 184 intervertebral discs (IVDs) from 19 dogs of different breeds were used. The extent of IVDD was evaluated by macroscopic grading, histopathology, glycosaminoglycan content, and matrix metalloproteinase 2 activity. Canine data were compared with human IVD data acquired in this study or from the literature.Results. Gross pathology of IVDD in both dog types (CD and NCD) and humans showed many similarities, but the cartilaginous endplates were significantly thicker and the subchondral cortices significantly thinner in humans than in dogs. Notochordal cells were still present in the IVDs of adult NCD but were not seen in the CD breeds or in humans. Signs of degeneration were seen in young dogs of CD breeds (<1 year of age), whereas this was only seen in older dogs of NCD breeds (5-7 years of age). The relative glycosaminoglycan content and metalloproteinase 2 activity in canine IVDD were similar to those in humans: metalloproteinase 2 activity increased and glycosaminoglycan content decreased with increasing severity of IVDD.Conclusion. IVDD is similar in humans and dogs. Both CD and NCD breeds may therefore serve as models of spontaneous IVDD for human research. However, as with all animal models, it is important to recognize interspecies differences and, indeed, the intraspecies differences between CD and NCD breeds (early vs. late onset of IVDD, respectively) to develop an optimal canine model of human IVDD.
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| 3. |
- Ostman, Maria, et al.
(författare)
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Novel Calcium Phosphate Promotes Interbody Bony Fusion in a Porcine Anterior Cervical Discectomy and Fusion Model
- 2024
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Ingår i: Spine. - : Wolters Kluwer. - 0362-2436 .- 1528-1159. ; 49:17, s. 1179-1186
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Tidskriftsartikel (refereegranskat)abstract
- Study Design: Experimental porcine anterior cervical discectomy and fusion (ACDF) model: a proof-of-concept study.Objective.The effect of monetite synthetic bone graft (SBG) containing calcium pyrophosphate and beta-tricalcium phosphate on cervical spinal fusion in a noninstrumented two-level large animal model.Summary of Background Data: ACDF is the gold standard surgical technique for the treatment of degenerative cervical spinal diseases. However, pseudarthrosis associated with increased patient morbidity occurs in similar to 2.6% of the surgeries. SBG may enhance bony fusion and subsequently decrease the risk of pseudarthrosis. Recent studies on monetite-based SBGs for use in large cranial defects in humans have shown promising bone healing results, necessitating further investigation of their use in cervical spinal fusion.Materials and Methods: Four adult female Danish G & ouml;ttingen minipigs received partial cervical anterior discectomy and intervertebral defects at an upper and lower level. One defect was filled with SBG, and the other was left empty. Bony fusion was evaluated using computed tomography (CT) at three-month intervals for 12 months. Fifteen months postsurgery, the animals were euthanized for further ex vivo qualitative histopathologic and micro-CT evaluations. Fusion rates were compared using the Fisher exact test at each time point.Results.Increased interbody bony fusion rates were observed at SBG levels (4/4) compared with control levels (0/4) evaluated by CT at 6 and 9 months postsurgery (P=0.029). Fusion was observed at all SBG levels 12 months postsurgery and at only one control level. Histopathologic evaluation confirmed high-quality interbody bony fusion at all SBG levels and fusion by spondylosis at one control level.Conclusion: This proof-of-concept study provides preliminary evidence of a novel, calcium pyrophosphate-containing, and beta-tricalcium phosphate-containing monetite SBG that promotes bony fusion compared with a negative control in a clinically relevant porcine model of ACDF.
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| 4. |
- Stenlund, Tobias, et al.
(författare)
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Double-sided Mechanical Shocks Provoke Larger Seated Postural Reactions Compared to Single-Sided Mechanical Shocks
- 2018
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Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 43:8, s. E482-E487
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Human volunteers were exposed experimentally to single-sided mechanical shocks (SSMS) and double-sided mechanical shocks (DSMS) while seated.OBJECTIVE: To describe and contrast seated postural reactions due to SSMS or DSMS in healthy male adults.SUMMARY OF BACKGROUND DATA: Mechanical shocks to the body, caused when driving on irregular terrain, are suggested to be hazardous to the spine and may be associated with the reported musculoskeletal pain of the back and neck among professional drivers. However, very little is known about the characteristics of seated postural reactions and the biomechanical effects caused by mechanical shocks.METHODS: Twenty healthy male subjects (18-43 years old) were exposed while seated to 5 SSMS and 15 DSMS in lateral directions. The second acceleration in the DSMS was in the opposite direction to the first acceleration and was either fast, medium or slow depending on the speed of direction change. Surface electromyography (EMG) was recorded in muscles of the upper neck, trapezius, erector spinae and external oblique while kinematics were recorded with inertial sensors placed at the neck, trunk and pelvis. Muscle activity was normalized to maximum voluntary contractions (MVC).RESULTS: The EMG amplitudes were significantly higher (0.6-1%; p < 0.001) for the fast DSMS compared to all other shocks. Range of motion (ROM) of the neck and trunk was greater during the DSMS compared to the SSMS. Evoked muscle activity was less than 2% MVC in the trapezius, less than 10% MVC in the erector spinae and upper neck while the activity exceeded 10% MVC in the external oblique muscles.CONCLUSION: Fast DSMS in lateral directions appear more demanding compared to SSMS, demonstrating augmented seated postural reactions. However, the present mechanical shocks employed did not seem to induce postural reactions with regard to ROM or muscle activity of a magnitude likely to cause musculoskeletal overload.LEVEL OF EVIDENCE: 4.
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