| 1. |
- Barreto Henriksson, Helena, et al.
(författare)
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Identification of Cell Proliferation Zones, Progenitor Cells and a Potential Stem Cell Niche in the Intervertebral Disc Region: A Study in Four Species.
- 2009
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Ingår i: SPINE. - 0362-2436. ; 34:21, s. 2278-2287
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN.: Descriptive experimental study in 4 different mammals. OBJECTIVE.: To investigate cell proliferation/regeneration and localize stem cells/progenitor cells within the intervertebral disc (IVD). SUMMARY OF BACKGROUND DATA.: Disc degeneration (DD) is believed to play a major role in patients with chronic lumbar pain. Lately, biologic treatment options for DD have gained increasing interest. Normal regeneration processes within the IVD and have previously been sparsely described and therefore it is of great interest to increase the knowledge about these processes. METHODS.: Detection of cell proliferations zones and label-retaining cells were done by in vivo 5-bromo-2-deoxyuridine (BrdU) labeling in 18 rabbits, killed after 4, 6, 10, 14, 28, or 56 days. Results were visualized with immunohistochemistry and fluorescence/confocal microscopy. Localization of progenitor cell were further investigated by immunohistochemistry using antibodies towards Notch1, Delta4, Jagged1, C-KIT, KI67, and Stro-1 in normal IVD from rabbits (n = 3), rats (n = 2), minipigs (n = 2), and in human degenerated IVD (n = 4). Further, flowcytometry analysis using progenitor markers were performed on additional human IVD cells (n = 3). RESULTS.: BrdU positive cells were found in comparable numbers at early and late time points in most regions of the anulus fibrosus (AF) and nucleus pulposus demonstrating slow ongoing cell proliferation. In the AF border to ligament zone (AFo) and the perichondriumregion (P) a stem cell niche-like pattern was determined (a high number of BrdU positive cells at early time points vs. only a few label retaining cells at later time points). In normal and DD tissue from the 4 investigated species progenitor cell markers were detected. CONCLUSION.: The IVD is a tissue with ongoing slow cell proliferation both in the AF and the nucleus pulposus. The stem cell niche pattern detected in AFo and P can be suggested to play a role for IVD morphology and function. These findings may be of importance for the development of biologic treatment strategies. PMID: 19755937 [PubMed - as supplied by publisher]
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| 2. |
- Barreto Henriksson, Helena, et al.
(författare)
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Transplantation of human mesenchymal stems cells into intervertebral discs in a xenogeneic porcine model.
- 2009
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Ingår i: Spine. - 1528-1159. ; 34:2, s. 141-8
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Experimental and descriptive study of a xenotransplantation model in minipigs. OBJECTIVE: To study survival and function of human mesenchymal stem cells (hMSCs) after transplantation into injured porcine spinal discs, as a model for cell therapy. SUMMARY OF BACKGROUND DATA: Biologic treatment options of the intervertebral disc are suggested for patients with chronic low back pain caused by disc degeneration. METHODS: Three lumbar discs in each of 9 minipigs were injured by aspiration of the nucleus pulposus (NP), 2 weeks later hMSCs were injected in F12 media suspension (cell/med) or with a hydrogel carrier (Puramatrix) (cell/gel). The animals were sacrificed after 1, 3, or 6 months. Disc appearance was visualized by magnetic resonance imaging. Immunohistochemistry methods were used to detect hMSCs by antihuman nuclear antibody staining, and further performed for Collagen II, Aggrecan, and Collagen I. SOX 9, Aggrecan, Versican, Collagen IA, and Collagen IIA and Collagen IIB human mRNA expression was analyzed by real-time PCR. RESULTS: At magnetic resonance imaging all injured discs demonstrated degenerative signs. Cell/gel discs showed fewer changes compared with cell/med discs and only injured discs at later time points. hMSCs were detected in 9 of 10 of the cell/gel discs and in 8 of 9 of the cell/med discs. Immunostaining for Aggrecan and Collagen type II expression were observed in NP after 3 and 6 months in gel/cell discs and colocalized with the antihuman nuclear antibody. mRNA expression of Collagen IIA, Collagen IIB, Versican, Collagen 1A, Aggrecan, and SOX9 were detected in both cell/med and cell/gel discs at the time points 3 and 6 months by real-time PCR. CONCLUSION: hMSCs survive in the porcine disc for at least 6 months and express typical chondrocyte markers suggesting differentiation toward disc-like cells. As in autologous animal models the combination with a three-dimensional-hydrogel carrier seems to facilitate differentiation and survival of MSCs in the disc. Xenotransplantation seems to be valuable in evaluating the possibility for human cell therapy treatment for intervertebral discs.
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| 3. |
- Svanvik, Teresia, et al.
(författare)
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Human Disk Cells from Degenerated Disks and Mesenchymal Stem Cells in Co-Culture Result in Increased Matrix Production.
- 2009
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Ingår i: Cell Tissues and Organs. - 1422-6405. ; 191:1, s. 2-11
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Tidskriftsartikel (refereegranskat)abstract
- Transplantation of mesenchymal stem cells (MSCs) has been suggested for disk degeneration, which is characterized by dysfunctional cells and low proteoglycan production. The aim of this study was to examine the effects of a 3D co-culture system using human disk cells (DCs) and MSCs on collagen and proteoglycan production. DCs and MSCs were expanded in monolayer and grown in pellet cultures for 7, 14 and 28 days and analyzed for hydroxyproline (HP), reflecting total collagen production, and glycosaminoglycan (GAG) accumulation. DCs and MSCs co-cultured at different ratios (25/75, 50/50 and 75%/25%) were examined for GAG accumulation. Collagen type II expression was analyzed immunohistochemically. In a second series, conditioned media were added to pellet cultures of degenerated DCs or MSCs. DCs from degenerated disks and MSCs demonstrated lower total collagen production than non-degenerated DC pellets. GAG production was comparable in DCs and MSCs, except in the youngest donor, with MSC producing about 10 times higher GAG/DNA. Co-cultures resulted in approximately 1.5 times higher GAG/DNA production than DCs. Increased collagen type II expression was seen in co-cultures compared to DC or MSC culture alone, except in the case with highly active MSCs. No positive effect of conditioned media was seen. In conclusion, co-culture of MSCs with degenerated DCs increased proteoglycan and collagen-type ceII production, indicating that in future clinical therapy MSCs can be transplanted without pre-differentiation in vitro. The lack of effect of conditioned media suggests that the positive effect of co-culture on matrix production is not due to soluble factors.
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| 4. |
- Brisby, Helena, 1965, et al.
(författare)
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In vivo measurement of facet joint nitric oxide in patients with chronic low back pain.
- 2007
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Ingår i: Spine. - 1528-1159. ; 32:14, s. 1488-92
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Tidskriftsartikel (refereegranskat)abstract
- Prospective case-control study testing a new diagnostic method.The aim of the present study was to investigate the concentration of nitric oxide (NO) in the perifacetal region in patients with chronic low back pain and healthy controls.Facet joint arthrosis may be a pain source in chronic back pain. Increased concentrations of NO, an oxygen-free radical, have been demonstrated in temporomandibular and knee joints with osteoarthritis.Patients with at least 6 months' duration of chronic low back pain and signs of facet joint osteoarthrosis (n = 24) and healthy volunteers (n = 7) were included. A detailed questionnaire, including visual analogue scale, was completed before and 6 weeks after the measurements. NO was measured with a custom-designed electrochemical real-time NO sensor inserted under fluoroscopic guidance. All patients received corticosteroids and local anesthetics after NO measurements.NO measurements were obtained from all participants. No adverse effects were noted. The patients with chronic low back pain demonstrated higher concentrations of NO in the perifacetal region compared with healthy controls (1.66 +/- 0.28 vs. 0.46 +/- 0.14 nmol/L, P = 0.007). No association between NO concentration and pain duration or pain level was detected. Patients with a positive response to local anesthetics and corticosteroid injection (defined as a >or=20 mm reduction of visual analogue scale at the 6-week follow-up visit) had higher NO concentrations than patients without positive response.The study demonstrates that it is feasible and safe to measure NO with a real time-sensor in or around the facet joints. The findings of higher concentrations of NO in the perifacetal region in chronic low back patients compared with healthy controls indicate that the degenerative process of the joints in these patients may cause increased NO production. The observation of higher NO concentrations in the perifacetal region in patients responding to corticosteroid/local anesthetic infiltration indirectly suggest a more pronounced inflammatory process in these patients.
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| 5. |
- Brisby, Helena, 1965
(författare)
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Pathology and possible mechanisms of nervous system response to disc degeneration
- 2006
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Ingår i: J Bone Joint Surg Am. - 0021-9355. ; 88 Suppl 2, s. 68-71
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Tidskriftsartikel (refereegranskat)abstract
- Degeneration of the intervertebral disc is clinically considered to be an important source of pain in patients with low-back pain. Disc deterioration and/or degeneration may influence the nervous system by stimulation of nociceptors in the anulus fibrosus, causing nociceptive pain that is often referred to as discogenic pain. The stimulation of the nociceptors may be of mechanical or inflammatory origin. Deterioration of a disc with loss of normal structure and weight-bearing properties may lead to abnormal motions that cause mechanical stimulation. This theory is supported by the fact that patients commonly experience an increase in pain with weight-bearing and certain movements. In addition, an ingrowth of vessels and nerve fibers into deeper layers of the anulus fibrosus has been observed in degenerated discs. A large number of inflammatory and signaling substances, such as tumor necrosis factor and interleukins (interleukin-1beta, interleukin-6, and interleukin-8), may also play a role in the development of back pain. Independent of stimulus of the nociceptors, the pain impulses are conducted through myelinated A delta fibers and unmyelinated C fibers to the dorsal root ganglion and continue by way of the spinothalamic tract to the thalamus and the somatosensory cortex. In response to stimulation of the nociceptors in the disc, the somatosensory system may increase its sensitivity, resulting in a nonfunctional response; that is, normally innocuous stimuli may generate an amplified response (peripheral sensitization). When disc degeneration leads to a disc herniation, the adjacent nervous system structures, such as the nerve roots or the dorsal root ganglion, can be affected, causing neuropathic pain of mechanical or biochemical origin. Disc deterioration also influences other spinal structures, such as facet joints, ligaments, and muscles, which can also become pain generators. Thus, disc degeneration may be responsible for the development of chronic low-back pain without being the actual pain focus. Both nociceptive and neuropathic pain can be modulated at higher centers, both at the spinal and the supraspinal levels (central sensitization). The altered magnitude of perceived pain is often referred to as neural plasticity and is considered to play a critical role in the evolution of chronic pain. Together with the complexity of the nervous system and pain modulation mechanisms, psychological aspects may also play a role in the response of the nervous system in patients with chronic low-back pain caused by disc degeneration.
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| 6. |
- Brisby, Helena, 1965, et al.
(författare)
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Thalamic activation in a disc herniation model.
- 2007
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Ingår i: Spine. - 1528-1159. ; 32:25, s. 2846-52
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: A novel approach combining a rodent disc herniation model with electrophysiologic recordings of thalamic evoked responses. OBJECTIVE: To assess short-term effects of nucleus pulposus (NP) application on dorsal root ganglions (DRG) on high threshold afferent fiber evoked activation in the thalamus. SUMMARY OF BACKGROUND DATA: Epidural application of NP in combination with mechanical compression induces pain related behavior in rats associated with enhanced activity of pain-processing neurons in the dorsal horn of the spinal cord. However, possible effects on neuronal activity in the pain processing ventral posterior lateral (VPL) thalamic nucleus following NP application on DRG have not been investigated. METHODS: Responses in the contralateral VPL evoked by electrical stimulation of the sciatic nerve and of the fourth lumbar (L4) DRG were recorded in adult Sprague-Dawley rats. Records were obtained before and during application (5, 10, and 20 minutes) of NP or of adipose tissue (AT) to the L4 DRG. AT was used as control for mechanical effects of NP application. RESULTS: Application of NP resulted in an increase of evoked thalamic responses to 138% +/- 10% of control after 20 minutes (P < 0.01), whereas AT application for 20 minutes resulted in a reduction of evoked responses to 77% +/- 4% (P < 0.05). Recordings in control animals (i.e., with no application) demonstrated stable evoked neuronal thalamic activity for up to 40 minutes. CONCLUSION: The study demonstrates that NP application onto DRG increases afferent fiber evoked responses in the thalamus and in view of the opposite effects of AT application suggests that these effects may be specific for NP. The results show that NP affects sensory transmitting pathways within a few minutes, possibly due to rapid and reversible alterations in the neuronal excitability. The study thus introduces a rodent model for studying sensory afferent evoked thalamic activity related to DRG injury which may be used to evaluate analgesics and anti-inflammatory drugs used for pain relief in disc herniation and neuropathic pain patients.
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| 7. |
- Halldin, Klas, 1967, et al.
(författare)
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Three-dimensional radiological classification of lumbar disc herniation in relation to surgical outcome
- 2009
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Ingår i: International Orthopaedics. - : Springer Science and Business Media LLC. - 0341-2695 .- 1432-5195. ; 33:3, s. 725-30
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Tidskriftsartikel (refereegranskat)abstract
- Centrally located lumbar disc herniations have been reported to be of predictive value for poor post-operative clinical outcome. One hundred and fifty patients undergoing lumbar disc herniation surgery were prospectively included. Herniation-related parameters, including the grading of contours, were assessed from pre-operative computed tomography (CT) and magnetic resonance imaging (MRI) images using a new three-dimensional grading system. The radiological findings were compared with outcome parameters two years post-operatively (patient-assessed pain, function/health scores and evaluation by an independent observer). An intra- and inter-observer validation of the classification was performed in a subgroup of patients. High intra-observer and good inter-observer reliability for both CT and MRI was seen. In the study population, no relation between the distribution or size of the herniations and outcome at 2-year follow-up were found. The distribution and size of the lumbar disc herniations with the three-dimensional classification were not found to be of importance for the clinical outcome.
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| 8. |
- Karlsson, Camilla, 1977, et al.
(författare)
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Differentiation of human mesenchymal stem cells and articular chondrocytes: analysis of chondrogenic potential and expression pattern of differentiation-related transcription factors.
- 2007
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Ingår i: Journal of orthopaedic research : official publication of the Orthopaedic Research Society. - : Wiley. - 0736-0266. ; 25:2, s. 152-63
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stem cells (MSCs) are a candidate for replacing chondrocytes in cell-based repair of cartilage lesions. However, it has not been clarified if these cells can acquire the hyaline phenotype, and whether chondrocytes and MSCs show the same expression patterns of critical control genes in development. In order to study this, articular chondrocytes and iliac crest derived MSCs were allowed to differentiate in pellet mass cultures. Gene expression of markers for the cartilage phenotype, helix-loop-helix (HLH) transcription factors, and chondrogenic transcription factors were analyzed by real-time PCR. Matrix production was assayed using biochemical analysis for hydroxyproline, glycosaminoglycans, and immunohistochemistry for collagen types I and II. Significantly decreased expression of collagen type I was accompanied by increased expression of collagen types IIA and IIB during differentiation of chondrocytes, indicating differentiation towards a hyaline phenotype. Chondrogenesis in MSCs on the other hand resulted in up-regulation of collagen types I, IIA, IIB, and X, demonstrating differentiation towards cartilage of a mixed phenotype. Expression of HES1 increased significantly during chondrogenesis in chondrocytes while expression in MSCs was maintained at a low level. The HLH gene HES5 on the other hand was only detected in chondrocytes. Expression of ID1 decreased significantly in chondrocytes while the opposite was seen in MSCs. These findings suggest that chondrocytes and MSCs differentiated and formed different subtypes of cartilage, the hyaline and a mixed cartilage phenotype, respectively. Differentially regulated HLH genes indicated the possibility for HLH proteins in regulating chondrogenic differentiation. This information is important to understand the potential use of MSCs in cartilage repair.
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| 9. |
- Rönnberg, Katarina, 1969, et al.
(författare)
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Patients' satisfaction with provided care/information and expectations on clinical outcome after lumbar disc herniation surgery
- 2007
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Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 0362-2436 .- 1528-1159. ; 32:2, s. 256-261
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN. A prospective study of patients undergoing lumbar disc herniation surgery. OBJECTIVES. To assess patients' satisfaction with care/preoperative information, if expectations on surgical results and ability to return to work are related to baseline characteristics, and/or can predict self-reported outcome. Self-reported outcome was compared with objective outcome. SUMMARY OF BACKGROUND DATA. Patients' expectations on treatment results have been discussed as a predictive factor for postoperative outcome and satisfaction demonstrated to be directly related to patient expectations. METHODS. The study includes 148 patients, 46% women, mean age 40 (range 18-66). Before and 2 years after surgery, questionnaires about given information/care, expected/present work ability, and expectations on/obtained improvement of physical functions/symptoms (leg and back pain, sensibility, and muscle function) were filled in. The visual analog scale leg pain, Zung Depression Scale, and Oswestry Disability Index were used as baseline characteristics. At 2-year follow-up, self-reported and objective outcome was assessed. RESULTS. Satisfaction with given information/care were reported by 46% and 82%, respectively. Zung Depression Scale related to expectations on leg pain recovery (P = 0.022), work ability (P = 0.046), and satisfaction with given information (P = 0.031). Patients who expected to return (76%) and not return (24%) to work, returned in 78% and 26%, respectively (P = 0.021). A high agreement between self-reported outcome and objective outcome were found (P < 0.001). CONCLUSIONS. Patients undergoing lumbar disc herniation surgery are mostly satisfied with provided care before and after surgery, however, less satisfied with information provided. Further, patients with preoperative positive expectations on work return and realistic expectations on pain and physical recovery have a greater chance to be satisfied with the surgical results. © 2007 Lippincott Williams & Wilkins, Inc.
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| 10. |
- Rönnberg, Katarina, 1969, et al.
(författare)
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Peridural scar and its relation to clinical outcome : A randomised study on surgically treated lumbar disc herniation patients
- 2008
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Ingår i: European spine journal. - : Springer. - 0940-6719 .- 1432-0932. ; 17:12, s. 1714-1720
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Tidskriftsartikel (refereegranskat)abstract
- A prospective randomised 2-year follow-up study on patients undergoing lumbar disc herniation surgery. The objective was to investigate the relationship between peridural scarring and clinical outcome, the scar development 6 and 24 months postoperatively by using MRI, and if ADCON-L (a bioresorbable carbohydrate polymer gel) has an effect on scar size and/or improve patients' outcome after lumbar disc herniation surgery. The association between peridural scarring and recurrent pain after lumbar disc herniation surgery is debated. Numerous materials have been used in attempts to prevent or reduce postoperative peridural scarring; however, there are conflicting data regarding the clinical effects. The study included 119 patients whose mean age was 39 years (18-66); 51 (47%) were women. Sixty patients (56%) were perioperatively randomised to receive ADCON-L, and 48 (44%) served as controls. All patients underwent MRI at 6 and 24 months postoperatively, and an independent radiologist graded the size, location and development of the scar, by using a previously described scoring system. Pre- and 2-year postoperatively patients graded their leg pain on a visual analogue scale (VAS). At the 2-year follow-up patients rated their satisfaction with treatment (subjective outcome) and were evaluated by an independent neurologist (objective outcome), using MacNab score. There was no relationship between size or localisation of the scar and any of the clinical outcomes (VAS, subjective and objective outcome). The scar size decreased between 6 and 24 months in 49%, was unchanged in 42% and increased in 9% of the patients. Patients treated with ADCON-L did not demonstrate any adverse effects, nor did they demonstrate less scarring or better clinical outcome than control patients. No significant association between the presence of extensive peridural scar or localisation of scar formation and clinical outcome could be detected in the present study. Further, no positive or negative effects of ADCON-L used in disc herniation surgery could be seen.
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