| 1. |
- Casar-Borota, Olivera, et al.
(författare)
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A novel dynamin-2 gene mutation associated with a late-onset centronuclear myopathy with necklace fibres
- 2015
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Ingår i: Neuromuscular Disorders. - : Elsevier BV. - 0960-8966 .- 1873-2364. ; 25:4, s. 345-348
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear centralisation and internalisation, sarcoplasmic radiating strands and type 1 muscle fibre predominance and hypotrophy characterise dynamin-2 (DNM2) associated centronuclear myopathy, whereas necklace fibres are typically seen in late onset myotubularin-1 (MTM1)-related myopathy. We report a woman with unilateral symptoms probably related to brachial plexus neuritis. Electromyography revealed localised neuropathic and generalised myopathic abnormalities. The typical features of DNM2 centronuclear myopathy with additional necklace fibres were found in the muscle biopsy. Sequencing of the DNM2 and MTM1 genes revealed a novel heterozygous missense mutation in exon 18 of the DNM2, leading to replacement of highly conserved proline at position 647 by arginine. The muscle symptoms have not progressed during the 3-year follow-up. However, the patient has developed bilateral subtle lens opacities. Our findings support the concept that necklace fibres may occasionally be found in DNM2-related myopathy, possibly indicating a common pathogenic mechanism in DNM2 and MTM1 associated centronuclear myopathy. (C) 2015 Elsevier B.V. All rights reserved.
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| 2. |
- Casar-Borota, Olivera, et al.
(författare)
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A novel dynamin-2 gene mutation associated with a late-onset centronuclear myopathy with unusual clinical presentation and necklace fibres
- 2012
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Ingår i: Neuromuscular Disorders. - Oxford : Elsevier BV. - 0960-8966 .- 1873-2364. ; 22:9-10, s. 843-843
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Nuclear centralisation and internalisation, sarcoplasmic radiating strands and type 1 muscle fibre predominance and hypotrophy are morphologic features of centronuclear myopathy (CNM) related to dynamin-2 (DNM2) gene defects, whereas necklace fibres characterise late-onset myopathy associated with myotubularin-1 (MTM1) gene defects. We report a 40-year-old woman with 1-year history of pain and paresthesia in the left shoulder and arm that was clinically interpreted as brachial plexus neuritis. Electromyography revealed both myopathic and neuropathic abnormalities, and because of the myopathic changes a muscle biopsy was performed. The typical morphologic features of dynamin-2 CNM with additional numerous necklace fibres were found in the muscle biopsy. Sequencing of the DNM2 and MTM1 genes revealed a not previously described heterozygous missense mutation in exon 18 of DNM2 leading to replacement of highly conserved Proline in position 647 by Arginine. The muscle symptoms have not progressed during the two-year follow-up, but the patient has developed bilateral subtle lens opacities. Necklace fibres were originally described as fibres that had usually a small diameter and internalized nuclei aligned in a basophilic ring at a few micrometers beneath the sarcolemma. They were described in association with myopathies caused by MTM1 mutations, and similar but not identical fibres have also been reported in a case of DNM2 associated CNM. Our findings support the concept that necklace fibres are not specific but indicate common pathogenic mechanisms in DNM2 and MTM1 associated CNM. This case report expands the clinical, morphological and molecular genetic variability of DNM2 associated CNM.
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| 3. |
- Casar-Borota, Olivera, et al.
(författare)
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Expression of SSTR2a, but not of SSTRs 1, 3, or 5 in Somatotroph Adenomas Assessed by Monoclonal Antibodies Was Reduced by Octreotide and Correlated With the Acute and Long-Term Effects of Octreotide
- 2013
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 98:11, s. E1730-E1739
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Tidskriftsartikel (refereegranskat)abstract
- Context: Reduced expression of somatostatin receptors (SSTRs) in somatotroph adenomas and their potential down-regulation after medical treatment may explain the unsatisfactory response to octreotide in particular acromegalic patients. The expression of SSTRs other than SSTR2a has not been studied in large, unselected cohorts using novel rabbit monoclonal antibodies. Objective: We aimed to determine the expression of SSTRs 1, 2a, 3, and 5 in somatotroph adenomas, to correlate expression with clinical characteristics and the response to octreotide, and to ascertain whether preoperative octreotide treatment affected SSTR expression. Design, Setting, Patients: The study included 78 adenomas from patients operated on consecutively during 2000 to 2010. After exclusion of 13 patients, immunohistochemical analysis with rabbit monoclonal antibodies against SSTRs 1, 2a, 3, and 5 (clones UMB-7, -1, -5, and -4) was performed on 65 adenomas. Intervention: Twenty-eight patients received preoperative octreotide, and 37 patients were operated on without pretreatment. Twenty-six patients were randomized to direct surgery (n = 13) or to octreotide pretreatment (n = 13). Main Outcome Measure: SSTR expression was evaluated using a 12-grade scoring system. The responses to the octreotide test dose (GH reduction) and to 6 months of octreotide (IGF-I reduction) were measured. Results: The majority of adenomas showed membranous expression of SSTRs 2a and 5. SSTR2a expression was reduced in the pretreated group and correlated with the acute octreotide test results and the effect of octreotide treatment. In a linear regression model with SSTR2 a expression as the determinant, the correlation with the acute test response improved after adjustment for medical pretreatment. Conclusion: Rabbit monoclonal antibodies are reliable markers of SSTRs in somatotroph adenomas. SSTR2a expression correlated with the response to octreotide and was reduced after octreotide treatment, indicating the need for adjustment when SSTR2a expression is correlated with baseline characteristics. Evaluation of SSTR subtypes may be an important aspect of improving the medical treatment for acromegaly.
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| 4. |
- Casar-Borota, Olivera, et al.
(författare)
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KIT protein expression and mutational status of KIT gene in pituitary adenomas
- 2012
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Ingår i: Virchows Archiv. - New York : Springer-Verlag New York. - 0945-6317 .- 1432-2307. ; 460:2, s. 171-181
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Tidskriftsartikel (refereegranskat)abstract
- KIT protein expression and mutational status of KIT gene in different types of tumours have been intensively studied since Imatinib Mesylate, KIT/PDGFRA tyrosine kinase inhibitor became available. However, only one immunohistochemical study on KIT expression in pituitary adenomas has been published. There are currently no reports on mutational status of KIT gene in pituitary adenomas. We have immunohistochemically investigated KIT expression in 252 pituitary adenomas and found cytoplasmic reactivity in 52.4% and membranous reactivity in 8.3% of all adenomas. There was statistically significant difference in KIT expression between clinically non-functioning, growth hormone- and adrenocorticotroph hormone-producing adenomas. The group with membranous expression was dominated by somatotropinomas and clinically non-functioning adenomas. KIT expression in a subset of adenomas was also confirmed by western blot analysis of 48 adenomas. Immunohistochemical KIT expression was correlated with basic clinical data and in a cohort of acromegalic patients with additional data (somatostatin receptor type 2A expression, response to somatostatin analogue treatment and mutational status of gsp oncogene). Exons 9, 11, 13 and 17 of KIT gene were searched for mutations in the tumours with membranous KIT expression and in a minority of tumours with cytoplasmic KIT expression using denaturing high-performance liquid chromatography and in suspected cases sequencing of one or more exons. No mutations in the examined exons were found. Our results may suggest a role of KIT in the pathogenesis of a subset of pituitary adenomas and point out the need for further research to find out if KIT-reactive adenomas could be sensitive to Imatinib Mesylate.
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| 5. |
- Casar-Borota, Olivera, et al.
(författare)
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Spindle cell oncocytoma of the adenohypophysis : report of a case with marked cellular atypia and recurrence despite adjuvant treatment.
- 2009
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Ingår i: Clinical Neuropathology. - 0722-5091. ; 28:2, s. 91-95
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Tidskriftsartikel (refereegranskat)abstract
- Spindle cell oncocytoma (SCO) of the adenohypophysis is a recently defined pituitary tumor mimicking a non-functioning macroadenoma and composed of mitochondrion rich tumor cells, positive for S-100, vimentin, epithelial membrane antigen and galectin-3 but lacking cytokeratins, pituitary hormones, and neuroendocrine markers. Derivation from pituitary folliculostellate cells (FSCs) has been suggested based upon immunohistochemical and ultrastructural characteristics shared by SCO and FSCs. 10 cases of SCO have been reported to date; of these, 8 underwent a benign clinical course and 2 recurred. We report a case of SCO with typical histologic and immunohistochemical features in addition to marked cellular pleomorphism and nuclear atypia. It showed slow regrowth over a 30-month period of follow-up despite combined surgical and radiotherapy. Despite the benign course of most reported cases, additional experience with longer follow-up are needed to assess clinical, histopathologic, and proliferative indices and their relevance to optimal therapy for this rare pituitary tumor.
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| 6. |
- Emblem, Kyrre E, et al.
(författare)
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Glioma grading by using histogram analysis of blood volume heterogeneity from MR-derived cerebral blood volume maps.
- 2008
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Ingår i: Radiology. - : Radiological Society of North America (RSNA). - 0033-8419 .- 1527-1315. ; 247:3, s. 808-17
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To retrospectively compare the diagnostic accuracy of an alternative method used to grade gliomas that is based on histogram analysis of normalized cerebral blood volume (CBV) values from the entire tumor volume (obtained with the histogram method) with that of the hot-spot method, with histologic analysis as the reference standard.MATERIALS AND METHODS: The medical ethics committee approved this study, and all patients provided informed consent. Fifty-three patients (24 female, 29 male; mean age, 48 years; age range, 14-76 years) with histologically confirmed gliomas were examined with dynamic contrast material-enhanced 1.5-T magnetic resonance (MR) imaging. CBV maps were created and normalized to unaffected white matter (normalized CBV maps). Four neuroradiologists independently measured the distribution of whole-tumor normalized CBVs and analyzed this distribution by classifying the values into area-normalized bins. Glioma grading was performed by assessing the normalized peak height of the histogram distributions. Logistic regression analysis and interobserver agreement were used to compare the proposed method with a hot-spot method in which only the maximum normalized CBV was used.RESULTS: For the histogram method, diagnostic accuracy was independent of the observer. Interobserver agreement was almost perfect for the histogram method (kappa = 0.923) and moderate for the hot-spot method (kappa = 0.559). For all observers, sensitivity was higher with the histogram method (90%) than with the hot-spot method (55%-76%).CONCLUSION: Glioma grading based on histogram analysis of normalized CBV heterogeneity is an alternative to the established hot-spot method, as it offers increased diagnostic accuracy and interobserver agreement.
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| 7. |
- Evang, Johan Arild, et al.
(författare)
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Reduced levels of E-cadherin correlate with progression of corticotroph pituitary tumours
- 2011
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Ingår i: Clinical Endocrinology. - Oxford : Wiley. - 0300-0664 .- 1365-2265. ; 75:6, s. 811-818
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES:Loss of E-cadherin is an important marker of epithelial tumour progression. The aims of this study were to explore whether E-cadherin expression and localization correlate to corticotroph tumour progression, relate the expression of the E-cadherin gene (CDH1) to immunohistochemical E-cadherin staining pattern, and study whether the E-cadherin levels were correlated to methylation status of the CDH1 promoter region.DESIGN:Immunohistochemical analyses of E-cadherin protein were performed, as was RT-qPCR of the CDH1 and the POMC genes. Methylation pattern of the promoter region of CDH1 was measured using pyrosequencing of bisulfite-treated DNA.PATIENTS:Forty-five patients operated at a tertiary referral centre in Oslo, Norway. Adenoma tissue sections and RNA samples from patients with verified Cushing's disease or Nelson's syndrome were collected.MEASUREMENTS:Expression of E-cadherin mRNA and protein in pituitary corticotroph adenomas and average percentage of methylated cytosines in a cytosine-phosphate-guanosine island of the CDH1 promoter.RESULTS:Correlations were observed between tumour progression and both nuclear expression of E-cadherin and reduced CDH1 mRNA. The E-cadherin expression was not determined by the methylation pattern of the CDH1 promoter.CONCLUSIONS:Corticotroph tumour progression was associated with reduced expression of the epithelial marker E-cadherin.
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| 8. |
- Fougner, Stine Lyngvi, et al.
(författare)
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Adenoma granulation pattern correlates with clinical variables and effect of somatostatin analogue treatment in a large series of patients with acromegaly
- 2012
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Ingår i: Clinical Endocrinology. - Malden : Wiley. - 0300-0664 .- 1365-2265. ; 76:1, s. 96-102
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT:Somatotroph adenomas have been classified into densely granulated (DG) and sparsely granulated (SG) tumours with a transitional, intermediate group. Gsp oncogenes are activating mutations in the Gsα subunit gene, found in approximately 40% of somatotroph adenomas.OBJECTIVES:To explore granulation pattern and presence of gsp oncogene in acromegaly with correlations to clinical and biochemical variables and to the effect of treatment with somatostatin analogues (SA), as well as to describe granulation pattern in adenomas with and without SA pretreatment.DESIGN/SETTINGS/PATIENTS:Seventy-eight patients with active acromegaly were included. Long-term SA efficacy was evaluated in 29 patients treated preoperatively and in ten treated postoperatively. Granulation pattern was examined, as were immunohistochemical analyses for E-cadherin and SSTR2a. Protein levels of E-cadherin and SSTR2a were measured (Western blot). Gsp mutation analysis was available for 74 adenomas.RESULTS:DG adenomas and the transitional group had higher serum levels of IGF-1 per tumour volume than SG (P = 0·009; P = 0·005). Acute and long-term SA responses were lower in SG (P = 0·001; P = 0·043). No correlation between gsp mutation and granulation was found, and no difference in granulation pattern according to preoperative SA treatment was demonstrated. A significant correlation between granulation and E-cadherin was found, where SG had lowest immunohistochemical expression, substantiated by protein levels, and a highly significant gradient was observed from DG, through the transitional group, to SG.CONCLUSIONS:Densely granulated adenomas were highly responsive to somatostatin analogues in contrast to SG adenomas. The transitional group behaved clinically more like DG adenomas. However, based on E-cadherin, a marker of dedifferentiation, the transitional group seemed to be a true intermediate.
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| 9. |
- Fougner, Stine L, et al.
(författare)
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The clinical response to somatostatin analogues in acromegaly correlates to the somatostatin receptor subtype 2a protein expression of the adenoma.
- 2008
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Ingår i: Clinical Endocrinology. - : Wiley. - 0300-0664 .- 1365-2265. ; 68:3, s. 458-65
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Reduced expression of the somatostatin receptor subtype 2 (SSTR2) has been suggested as an explanation for the poor response to octreotide in acromegaly, but studies correlating levels of SSTR2 mRNA to octreotide efficacy have been contradictory. Some studies have found better responses to somatostatin analogues in G-protein alpha subunit (Gsalpha) mutation (gsp oncogene)-positive adenomas. The aim of this study was to determine adenoma SSTR2a protein expression and gsp status in a large group of patients with acromegaly, and relate this to the clinical effect of octreotide.PATIENTS: Seventy-one patients were included. All underwent transsphenoidal surgery, 23 patients after preoperative octreotide treatment.MEASUREMENTS: The adenoma SSTR2a expression was examined by immunohistochemistry and Western blot analysis, and gsp status determined. An acute octreotide test was performed, and the change in IGF-1 level after 6 months preoperative octreotide treatment was recorded.RESULTS: The acute octreotide response in non-pretreated patients and the preoperative long-term octreotide response were significantly better in patients with adenomas containing a large proportion of cells that stained positively for SSTR2a by immunohistochemistry. However, the SSTR2a protein level assessed by Western blot did not correlate with the octreotide response. The preoperatively treated group had lower SSTR2a protein levels and fewer adenomas with a large percentage of positively stained cells. The gsp oncogene was detected in 43% of the adenomas but did not correlate to the octreotide response.CONCLUSION: The clinical effect of octreotide correlates with the proportion of cells positive for SSTR2a in immunohistochemical staining, rather than the adenoma SSTR2a protein level. There may be a down-regulation of SSTR2a during octreotide treatment.
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| 10. |
- Heck, Ansgar, et al.
(författare)
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Intensity of pituitary adenoma on T2-weighted magnetic resonance imaging predicts the response to octreotide treatment in newly diagnosed acromegaly
- 2012
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Ingår i: Clinical Endocrinology. - : Wiley. - 0300-0664 .- 1365-2265. ; 77:1, s. 72-78
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Tidskriftsartikel (refereegranskat)abstract
- Background Primary, preoperative medical treatment is an option in selected patients with acromegaly, but a subset of patients respond poorly. Valid prediction of response to somatostatin analogues (SA) might thus alter treatment stratification. The aims of this study were to assess whether T2 signal intensity could determine long-term response to first-line SA treatment and to assess clinical and biochemical baseline characteristics, as well as histological subtype in relation to the magnetic resonance imaging (MRI) appearances. Methods In 45 newly diagnosed patients, T2-weighted signal intensity of the tumour was classified into hypo-, iso- or hyperintense. Biochemical and clinical baseline variables for the three groups were compared. In 25 patients primarily treated with long-acting SA for a median of 6 months [interquartile range (IQR):155180 days], GH and IGF-1 reduction was assessed, and in 34 cases, immunohistochemical granulation pattern was evaluated. Results The results showed that 12 (27%) adenomas were hypointense, 15 (33%) isointense and 18 (40%) hyperintense. Median IGF-1 [ratio IGF-1/ULN; (upper limit of normal)] was 3.5 (2.34.9), 2.9 (2.63.8) and 1.9 (1.32.6), respectively (P = 0.006 for difference between groups). Median GH values (mu g/l) of a 3- to 5-point profile were 17.5 (6.135), 9.3 (6.032.5) and 4.1 (1.58.3), (P = 0.025). Median IGF-1 reduction (% of baseline) after first-line SA treatment was 51 (4970), 36 (1974) and 13 (542) (P = 0.03); median reduction in GH (% of baseline) was 86 (7294), 78 (6285) and 46 (170) (P = 0.02). T2 hyperintensity was associated with sparse granulation pattern on immunohistochemistry. Conclusion In patients with acromegaly, T2 signal intensity at diagnosis correlates with histological features and predicts biochemical outcome of first-line SA treatment.
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