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- Al Nimer, Faiez, et al.
(author)
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Lipocalin-2 is increased in progressive multiple sclerosis and inhibits remyelination
- 2016
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In: Neurology. - 2332-7812. ; 3:1
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Journal article (peer-reviewed)abstract
- Objective: We aimed to examine the regulation of lipocalin-2 (LCN2) in multiple sclerosis (MS) and its potential functional relevance with regard to myelination and neurodegeneration. Methods: We determined LCN2 levels in 3 different studies: (1) in CSF and plasma from a case-control study comparing patients with MS (n = 147) with controls (n = 50) and patients with relapsing-remitting MS (n = 75) with patients with progressive MS (n = 72); (2) in CSF and brain tissue microdialysates from a case series of 7 patients with progressive MS; and (3) in CSF at baseline and 60 weeks after natalizumab treatment in a cohort study of 17 patients with progressive MS. Correlation to neurofilament light, a marker of neuroaxonal injury, was tested. The effect of LCN2 on myelination and neurodegeneration was studied in a rat in vitro neuroglial cell coculture model. Results: Intrathecal production of LCN2 was increased predominantly in patients with progressive MS (p < 0.005 vs relapsing-remitting MS) and displayed a positive correlation to neurofilament light (p = 0.005). Levels of LCN2 in brain microdialysates were severalfold higher than in the CSF, suggesting local production in progressive MS. Treatment with natalizumab in progressive MS reduced LCN2 levels an average of 13% (p < 0.0001). LCN2 was found to inhibit remyelination in a dose-dependent manner in vitro. Conclusions: LCN2 production is predominantly increased in progressive MS. Although this moderate increase does not support the use of LCN2 as a biomarker, the correlation to neurofilament light and the inhibitory effect on remyelination suggest that LCN2 might contribute to neurodegeneration through myelination-dependent pathways.
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- Andersson, Ulrika, et al.
(author)
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Epidermal growth factor receptor family (EGFR, ErbB2-4) in gliomas and meningiomas
- 2004
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In: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 108:2, s. 135-142
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Journal article (peer-reviewed)abstract
- Overexpression of epidermal growth factor receptor (EGFR, ErbB1) correlates with enhanced malignant potential of many human tumor types including glioblastoma multiforme. The significance of EGFR expression in meningiomas is, however, unclear. Reports regarding the other EGFR family members, ErbB2-4, in brain tumors are sparse. In this study, the expression of the EGFR family members was analyzed in relation to various parameters for the clinical importance of these receptors in 44 gliomas and 26 meningiomas. In gliomas, quantitative real-time reverse transcription (RT)-PCR revealed the highest EGFR mRNA expression in high-grade gliomas, while ErbB2 and ErbB3 mRNA were detected only in a few high-grade gliomas. In contrast, ErbB4 expression was most pronounced in low-grade gliomas. Immunohistochemistry showed significantly higher EGFR protein expression in high-grade gliomas compared to low-grade gliomas (P= 0.004). ErbB2 protein expression was mainly seen in high-grade gliomas. ErbB3 protein expression was low in all gliomas analyzed. ErbB4 protein expression was significantly higher in low-grade gliomas than in high-grade gliomas (P= 0.007). In meningiomas, quantitative real-time RT-PCR revealed expression of EGFR, ErbB2, and ErbB4 mRNA in the majority of the tumors. ErbB3 was detected in only one of the meningiomas analyzed. Immunohistochemistry demonstrated high ErbB2 protein expression in meningiomas. An intriguing observation in astrocytomas and oligodendrogliomas grade II, was a significantly decreased overall survival for patients with high EGFR protein expression (P= 0.04). The high ErbB4 expression in low-grade compared to high-grade gliomas might suggest that ErbB4 acts as a suppressor of malignant transformation in brain tumors, which is in line with previous studies in other tumor types.
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- Andersson, Ulrika, et al.
(author)
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Heterogeneity in the expression of markers for drug resistance in brain tumors
- 2004
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In: Clinical Neuropathology. - 0722-5091. ; 23:1, s. 21-27
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Journal article (peer-reviewed)abstract
- Brain tumors, in general, display a multidrug-resistant phenotype. This study evaluated the immunohistochemical expression and distribution of P-glycoprotein (Pgp), multidrug resistance protein (MRP1), lung resistance protein (LRP) and O6 methylguanine-DNA methyltransferase (MGMT) in low- and high-grade astrocytoma, oligodendroglioma and in different subgroups of meningioma. The results revealed a marked heterogeneity in the expression and distribution among the analyzed tumors. In astrocytoma and oligodendroglioma, Pgp and MRP1 were observed in the capillary endothelium and in scattered tumor cells, whereas LRP occurred only in tumor cells. A pronounced expression of MGMT was found independent of the histopathological grade. An enhanced expression of MRP1 and LRP in astrocytoma and oligodendroglioma were more often evident in older patients (> 50 years). Survival analysis suggested a markedly decreased overall survival for patients suffering from low-grade glioma overexpressing Pgp. In meningioma, a heterogeneous expression of Pgp, MRP1, LRP and MGMT was seen with the most prominent staining localized to the capillary endothelium. Pgp was significantly more often overexpressed (p < 0.05) in transitional compared to meningothelial meningioma. The marked heterogeneity in the expression suggests that analysis of these factors can be of importance in the selection of individualized chemotherapy, regardless of tumor type.
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- Andersson, Ulrika, et al.
(author)
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Rapid induction of long-lasting drug efflux activity in brain vascular endothelial cells but not malignant glioma following irradiation
- 2002
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In: Medical Oncology. - 1357-0560 .- 1559-131X. ; 19:1, s. 1-9
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Journal article (peer-reviewed)abstract
- The influence of radiotherapy on malignant glioma multidrug resistance to chemotherapy was evaluated because patients with glioma often are treated with a combination of radiotherapy and chemotherapy. Multidrug resistance gene (MDR1, mdr1a, and mdr1b) transcripts were found in human and rat glioma cell lines. P-Glycoprotein (Pgp) was immunohistochemically detected in glioma cell lines and in the rat brain vascular endothelial cell line (RBE4). A multidrug resistance pump efflux activity assay demonstrated increased calcein efflux of RBE4 endothelial cells, but not glioma cells, 2 h after irradiation and still increased 14 d after irradiation. The increased efflux was equally inhibited by verapamil with or without irradiation. In the rat intracranial glioma model (BT4C), Pgp was demonstrated in capillary endothelial cells of the tumor tissue and surrounding normal brain, but not in tumor cells. The expression of gene transcripts or Pgp was not affected by irradiation. The results indicate that long-lasting verapamil-resistant drug efflux mechanisms are activated in brain endothelial cells after irradiation. The results might explain the poor efficacy of chemotherapy following radiotherapy and contribute to consideration of new treatment strategies in the management of malignant glioma.
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- Antonsson, Johan, et al.
(author)
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Diffuse reflectance spectroscopy measurements for tissue type discrimination during deep brain stimulation
- 2008
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In: Journal of neural engineering. - : IOP Publishing. - 1741-2560 .- 1741-2552. ; 5:2, s. 185-190
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Journal article (peer-reviewed)abstract
- Diffuse reflectance spectroscopy as a method for improving intracerebral guidance during functional neurosurgery has been investigated. An optical probe was developed for measurements during stereotactic and functional neurosurgery in man. The aim of the study was to investigate the spectral differences between white and grey matter and between white matter and functional targets. Diffuse reflectance spectroscopy measurements in ten patients were recorded at incremental steps towards and in three different functional targets (STN, GPi and Zi). The recorded spectra along the trajectory were sorted into white or grey matter, based on preoperative MRI images or the recorded spectral shape and intensity. The difference between tissue types was calculated as a quotient. Significant intensity differences between white and grey matter were found to be at least 14% (p < 0.05) and 20% (p < 0.0001) for MRI and spectral-sorted data respectively. The reflectance difference between white matter and the functional targets of GPi was higher than for STN and Zi. The results indicate that diffuse reflectance spectroscopy has a potential to be developed to a suitable complement to other intracerebral guidance methods.
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- Asklund, Thomas, et al.
(author)
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Synergistic Killing of Glioblastoma Stem-like Cells by Bortezomib and HADC Inhibitors.
- 2012
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In: Anticancer Research. - : International Institute of Anticancer Research. - 0250-7005 .- 1791-7530. ; 32:7, s. 2407-2413
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Journal article (peer-reviewed)abstract
- Background: The malignant brain tumour glioblastoma is a devastating disease that remains a therapeutic challenge. Materials and Methods: Effects of combinations of the US Food and Drug Administation (FDA) approved proteasome inhibitor bortezomib and the histone deacetylase (HDAC) inhibitors vorinostat, valproic acid and sodium phenylbutyrate were studied on primary glioblastoma stem cell lines and conventional glioblastoma cell lines. Cell survival, proliferation and death were analyzed by fluorometric microculture cytotoxicity assay (FMCA), propidium iodide labeling and flow cytometry, and cell cloning through limiting dilution and live-cell bright-field microscopy. Results: Bortezomib and the HDAC inhibitors showed synergistic cell killing at clinically relevant drug concentrations, while the conventional cell lines cultured in serum-containing medium were relatively resistant to the same treatments. Conclusion: These findings of synergistic glioblastoma stem cell killing by bortezomib and three different FDA-approved HDAC inhibitors confirm and expand previous observations on co-operative effects between these classes of drugs.
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- Asplund, Pär, et al.
(author)
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One hundred eleven Percutaneous Balloon Compressions for Trigeminal Neuralgia in a Cohort of 66 Patients with Multiple Sclerosis
- 2019
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In: Operative Neurosurgery. - : Oxford University Press. - 2332-4252 .- 2332-4260. ; 17:5, s. 452-459
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Journal article (peer-reviewed)abstract
- BACKGROUND: Trigeminal neuralgia associated with multiple sclerosis (MS-TN) is comparatively rare and larger series of percutaneous balloon compression (PBC) in such cases are few in the literature.OBJECTIVE: To evaluate the results after PBC for MS-TN with regards to therapeutic effect, side effects, and complications.METHODS: One hundred eleven procedures with PBC performed in 66 cases of MS-TN were analyzed. Therapeutic effect was measured as postoperative time to pain recurrence without medication. All complications were compiled and the sensory function was evaluated in a subgroup of cases.RESULTS: The initial pain free rate was 67% and the median time to pain recurrence was 8 mo. Thirty-six patients were treated with PBC only, and among them, the results were worse if treated 3 to 4 times before, compared to first treatment (P = .009-.034). Patients who had several PBCs had worse results already after the first surgery (P < .001). A significant number of patients had impaired sensation to light touch directly after surgery, which was normalized at the late follow-up. Sensimetric testing showed raised thresholds for perception and pain directly after surgery (P = .004-.03), but these were also normalized at the late follow-up.CONCLUSION: PBC is a treatment that can be effective for many patients with MS-TN. Repeated previous surgeries is a risk factor for an unsatisfactory outcome. However, the patients with multiple surgeries had less satisfactory results already at the first procedure, indicating that a therapy resistant disease can be predicted after the first two PBCs. Postoperative sensory deficits were common but not lasting.
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9. |
- Asplund, Pär, 1974-
(author)
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Percutaneous Balloon Compression for the Treatment of Trigeminal Neuralgia
- 2019
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Doctoral thesis (other academic/artistic)abstract
- Background. Trigeminal neuralgia (TN) is a paroxysmal unilateral facial pain condition. That it is rather rare is of little comfort to those who are affected, as TN is often described as one of the worst pains known to mankind. Advanced age and multiple sclerosis (MS) are risk factors for developing TN. The first line of treatment is medical, primarily with carbamazepine. When medical treatment fails, as it does in many patients, there are several surgical options. One of the minimally invasive options, suitable for patients with comorbidity, is percutaneous balloon compression (PBC). Despite its introduction in the early 1980s, PBC is arguably the least well studied of the minimally invasive procedures for the treatment of TN.Aims. The aim of this thesis was to evaluate the efficacy of PBC, both overall and in MS-TN patients specifically. Further, it intended to identify and evaluate pre- and intraoperative parameters associated with the efficacy of PBC. It also investigated changes in sensory function after PBC, and identified side effects and complications associated with PBC. Finally, it sought to evaluate how efficacy, side effects and complications differed between PBC and another minimally invasive technique; percutaneous retrogasserian glycerol rhizotomy (PRGR).Methods. Cohorts of patients treated with PBC in Umeå and Stockholm, and with PRGR in Umeå, were followed retrospectively. Data from an existing database was combined with data from medical records, radiographs and telephone interviews.Results. After PBC, 90 % of the patients were completely pain free without medication for TN. The median time to recurrence of pain was 28 months. In patients with concurrent MS, the initial success rate was 67 % and the median time to recurrence was 8 months. In patients without MS, who had not previously been treated surgically, the initial success rate was 91 % and the median time to recurrence was 48 months. The procedure could, however, be repeated with good results. A good compression, indicated by a pear-shaped balloon as seen on intraoperative lateral radiograph, was crucial to achieve good pain relief. Postoperative hypoesthesia was present in the majority of patients, but after 3-6 months, sensibility was partly or fully normalized in most patients. Severe complications were rare, but included transient cardiac arrest, meningitis and dysesthesia. The side effects profile was favorable to that of percutaneous retrogasserian glycerol rhizotomy, in that the latter produced more cases of dysesthesia and decreased corneal sensibility. The efficacy of the two treatments were, however, not significantly different.Conclusions. PBC is an effective and relatively safe treatment option for patients with TN refractory to medical treatment. It deserves its place among the standard treatments for TN, and could be considered for those patients eligible for surgery for which open surgery is a less suitable option.
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10. |
- Asplund, Pär, et al.
(author)
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Percutaneous Balloon Compression vs Percutaneous Retrogasserian Glycerol Rhizotomy for the Primary Treatment of Trigeminal Neuralgia
- 2016
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In: Neurosurgery. - : Wolters Kluwer. - 0148-396X .- 1524-4040. ; 78:3, s. 421-428
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Journal article (peer-reviewed)abstract
- BACKGROUND: Despite >30 years of clinical use, the literature is still sparse when it comes to comparisons between percutaneous balloon compression (PBC) and percutaneous retrogasserian glycerol rhizolysis (PRGR) as treatments for trigeminal neuralgia.OBJECTIVE: To perform a retrospective cohort comparison between PBC and PRGR with regard to therapeutic effect, side effects, and complications.METHODS: Medical records and follow-up data from 124 primary PRGRs performed from 1986 to 2000 and 82 primary PBCs performed from 2000 to 2013 were reviewed. All patients had undergone clinical sensory testing and assessment of sensory thresholds. Analyses were performed to compare duration of pain relief, frequency of sensory disturbances, and side effects.RESULTS: Median duration of pain relief was 21 months after PRGR and 20 months after PBC. Both methods carried a high risk of hypesthesia/hypalgesia (P < .001) that was partly reversed with time. Decreased corneal sensibility was common after PRGR (P < .001) but not after PBC. Dysesthesia was more common after PRGR (23%) compared after PBC (4%; P < .001). Other side effects were noted but uncommon.CONCLUSION: PBC and PRGR are both effective as primary surgical treatment of trigeminal neuralgia. Both carry a risk of postoperative hypesthesia, but in this series, the side effect profile favored PBC. Furthermore, PBC is technically less challenging, whereas PRGR requires fewer resources. Between these 2 techniques, we propose PBC as the primary surgical technique for percutaneous treatment of trigeminal neuralgia on the basis of its lower incidence of dysesthesia, corneal hypesthesia, and technical failures.ABBREVIATIONS: MS, multiple sclerosisPBC, percutaneous balloon compressionPRGR, percutaneous retrogasserian glycerol rhizotomyTN, trigeminal neuralgiaThis is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work, provided it is properly cited. The work cannot be changed in any way or used commercially.
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