Barrantes-Freer, Alonso

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.journal","Journal of Neurosurgery"],["dc.bibliographiccitation.lastpage","6"],["dc.contributor.author","Bettag, Christoph"],["dc.contributor.author","Hussein, Abdelhalim"],["dc.contributor.author","Schatlo, Bawarjan"],["dc.contributor.author","Barrantes-Freer, Alonso"],["dc.contributor.author","Abboud, Tammam"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Mielke, Dorothee"],["dc.date.accessioned","2022-06-01T09:39:47Z"],["dc.date.available","2022-06-01T09:39:47Z"],["dc.date.issued","2022"],["dc.description.abstract","OBJECTIVE Fluorescence-guided resection of cerebral metastases has been proposed as an approach to visualize residual tumor tissue and maximize the extent of resection. Critics have argued that tumor cells at the resection margins might be overlooked under microscopic visualization because of technical limitations. Therefore, an endoscope, which is capable of inducing fluorescence, has been applied with the aim of improving exposure of fluorescent tumor tissue. In this retrospective analysis, authors assessed the utility of endoscope assistance in 5-aminolevulinic acid (5-ALA) fluorescence–guided resection of brain metastases. METHODS Between June 2013 and December 2016, a standard 20-mg/kg dose of 5-ALA was administered 4 hours prior to surgery in 26 patients with suspected single brain metastases. After standard neuronavigated microsurgical tumor resection, a microscope capable of inducing fluorescence was used to examine tumor margins. The authors classified the remaining fluorescence into 3 grades (0 = none, 1 = weak, and 2 = strong). Endoscopic assistance was employed if no or only weak fluorescence was visualized at the resection margins under the microscope. Endoscopically identified fluorescent tissue at the margins was resected and evaluated separately via histological examination to prove or disprove tumor infiltration. RESULTS Under the microscope, weakly fluorescent tissue was seen at the margins of the resection cavity in 15/26 (57.7%) patients. In contrast, endoscopic inspection revealed strongly fluorescent tissue in 22/26 (84.6%) metastases. In 11/26 (42.3%) metastases no fluorescence at the tumor margins was detected by the microscope; however, strong fluorescence was visualized under the endoscope in 7 (63.6%) of these 11 metastases. In the 15 metastases with microscopically weak fluorescence, strong fluorescence was seen when using the endoscope. Neither microscopic nor endoscopic fluorescence was found in 4/26 (15.4%) cases. In the 26 patients, 96 histological specimens were obtained from the margins of the resection cavity. Findings from these specimens were in conjunction with the histopathological findings, allowing identification of metastatic infiltration with a sensitivity of 95.5% and a specificity of 75% using endoscope assistance. CONCLUSIONS Fluorescence-guided endoscope assistance may overcome the technical limitations of the conventional microscopic exposure of 5-ALA–fluorescent metastases and thereby increase visualization of fluorescent tumor tissue at the margins of the resection cavity with high sensitivity and acceptable specificity."],["dc.identifier.doi","10.3171/2022.3.JNS212301"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/108564"],["dc.notes.intern","DOI-Import GROB-572"],["dc.relation.eissn","1933-0693"],["dc.relation.issn","0022-3085"],["dc.title","Endoscope-assisted visualization of 5-aminolevulinic acid fluorescence in surgery for brain metastases"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1321"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Acta Neurochirurgica"],["dc.bibliographiccitation.lastpage","1324"],["dc.bibliographiccitation.volume","159"],["dc.contributor.author","Hernandez-Duran, S."],["dc.contributor.author","Barrantes-Freer, Alonso"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","von der Brelie, Christian"],["dc.date.accessioned","2018-11-07T10:22:12Z"],["dc.date.available","2018-11-07T10:22:12Z"],["dc.date.issued","2017"],["dc.description.abstract","Posterior reversible encephalopathy syndrome (PRES) is thought to result from endothelial dysfunction and breakdown of the blood-brain barrier with subsequent vasogenic edema. Abrupt hypertension has been identified as one of its risk factors. We present a rare case of PRES in the anterior circulation with sudden onset of left hemiparesis and rapid neurological deterioration on the basis of hypertensive crisis. Due to refractory intracranial hypertension, the patient required emergent right decompressive craniectomy. Further investigations, including a biopsy, revealed an atypical form of PRES. This case illustrates the importance of aggressive medical and early surgical management to prevent permanent neurological deficits."],["dc.identifier.doi","10.1007/s00701-017-3197-x"],["dc.identifier.isi","000403508400022"],["dc.identifier.pmid","28516363"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42234"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Springer"],["dc.publisher.place","Wien"],["dc.relation.issn","0942-0940"],["dc.relation.issn","0001-6268"],["dc.title","Posterior reversible encephalopathy syndrome presenting in the anterior circulation with malignant intracranial hypertension requiring surgical decompression: a case report and literature review"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1037"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Acta Neurochirurgica"],["dc.bibliographiccitation.lastpage","1045"],["dc.bibliographiccitation.volume","161"],["dc.contributor.author","Fiss, Ingo"],["dc.contributor.author","Hussein, Abdelhalim"],["dc.contributor.author","Barrantes-Freer, Alonso"],["dc.contributor.author","Sperling, Swetlana"],["dc.contributor.author","Hernandez-Duran, Silvia"],["dc.contributor.author","Wolfert, Christina"],["dc.contributor.author","Pukrop, Tobias"],["dc.contributor.author","Ninkovic, Milena"],["dc.contributor.author","Bleckmann, Annalen"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Mielke, Dorothee"],["dc.contributor.author","Schatlo, Bawarjan"],["dc.date.accessioned","2020-12-10T14:10:53Z"],["dc.date.available","2020-12-10T14:10:53Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1007/s00701-019-03842-3"],["dc.identifier.eissn","0942-0940"],["dc.identifier.issn","0001-6268"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/70910"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Cerebral metastases: do size, peritumoral edema, or multiplicity predict infiltration into brain parenchyma?"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Acta Neuropathologica Communications"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Christians, Arne"],["dc.contributor.author","Adel-Horowski, Antonia"],["dc.contributor.author","Banan, Rouzbeh"],["dc.contributor.author","Lehmann, Ulrich"],["dc.contributor.author","Bartels, Stephan"],["dc.contributor.author","Behling, Felix"],["dc.contributor.author","Barrantes-Freer, Alonso"],["dc.contributor.author","Stadelmann, Christine"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Stockhammer, Florian"],["dc.contributor.author","Hartmann, Christian"],["dc.date.accessioned","2020-12-10T18:41:23Z"],["dc.date.available","2020-12-10T18:41:23Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1186/s40478-019-0817-0"],["dc.identifier.eissn","2051-5960"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16626"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/77568"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.intern","Merged from goescholar"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","The prognostic role of IDH mutations in homogeneously treated patients with anaplastic astrocytomas and glioblastomas"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","55"],["dc.bibliographiccitation.journal","Diagnostic Pathology"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Behling, Felix"],["dc.contributor.author","Barrantes-Freer, Alonso"],["dc.contributor.author","Skardelly, Marco"],["dc.contributor.author","Nieser, Maike"],["dc.contributor.author","Christians, Arne"],["dc.contributor.author","Stockhammer, Florian"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Tatagiba, Marcos"],["dc.contributor.author","Hartmann, Christian"],["dc.contributor.author","Stadelmann, Christine"],["dc.contributor.author","Schittenhelm, Jens"],["dc.date.accessioned","2018-11-07T10:12:37Z"],["dc.date.available","2018-11-07T10:12:37Z"],["dc.date.issued","2016"],["dc.description.abstract","Background: Treatment options for oncological diseases have been enhanced by the advent of targeted therapies. The point mutation of the BRAF gene at codon 600 (BRAF V600E) is found in several tumor entities and can be approached with selective inhibitory antibodies. The BRAF inhibitor vemurafenib has demonstrated clinical efficacy in patients with BRAF V600E-mutant melanoma brain metastases and in other cancer diseases. Therefore the BRAF V600E mutation is a highly interesting oncological target in brain tumors. Methods: This study assesses the BRAF V600E mutation status in 969 intracranial neoplasms using a tissue microarray method and immunohistochemical staining with the mutation-specific VE-1 antibody, followed by sequencing of positively stained cases. Results: Out of 784 primary brain tumors seven cases with a BRAF V600E mutation were detected (7/784, 1 %). Six of these cases were neuroepithelial tumors (6/667, 1 %) encompassing 2 astrocytomas WHO grade II (2/42, 5 %), 1 gliosarcoma WHO grade IV (1/75, 1 %) and 3 glioblastomas WHO grade IV (3/312, 1 %). Interestingly, all three mutant glioblastomas showed epithelioid histopathological features. Patients with V600E mutated astrocytic tumors were significantly younger (mean age 15.3 years) than wildtype cases (58.2 years). Among three rhabdoid meningiomas, one case was mutated (1/3) while all other grade I-III meningiomas (1/116, 1 %) and all fifty vestibular schwannomas analyzed were of wildtype status. The vast majority of the BRAF V600E mutations were found in cerebral metastases of malignant melanomas and carcinomas (29/135, 22 %), with false-positive staining found in four breast cancer cases and two non-small-cell lung carcinoma (NSCLC) samples. Conclusions: Our data suggest routine screening for BRAF V600E mutations for glioblastomas WHO grade IV below the age of 30, especially in glioblastomas with epithelioid features and in all rhabdoid meningiomas WHO grade III. For colorectal carcinoma, thyroid cancer, malignant melanoma and gliomas BRAF V600E immunostaining is sufficient for screening purposes. We also recommend routine immunohistochemical staining followed by sequencing validation in rare CNS metastases or metastases of unknown primary. Immunohistochemical analysis using mutation-specific antibodies on tissue microarrays is a feasible, time-and cost-efficient approach to high-throughput screening for specific mutations in large tumor series but sequencing validation is necessary in unexpected cases."],["dc.identifier.doi","10.1186/s13000-016-0506-2"],["dc.identifier.isi","000379298900001"],["dc.identifier.pmid","27350555"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13365"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40275"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Biomed Central Ltd"],["dc.relation.issn","1746-1596"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Frequency of BRAF V600E mutations in 969 central nervous system neoplasms"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","e0229274"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","PLoS One"],["dc.bibliographiccitation.volume","15"],["dc.contributor.author","Behling, Felix"],["dc.contributor.author","Barrantes-Freer, Alonso"],["dc.contributor.author","Behnes, Carl Ludwig"],["dc.contributor.author","Stockhammer, Florian"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Adel-Horowski, Antonia"],["dc.contributor.author","Rodríguez-Villagra, Odir Antonio"],["dc.contributor.author","Barboza, Miguel Angel"],["dc.contributor.author","Brück, Wolfgang"],["dc.contributor.author","Lehmann, Ulrich"],["dc.contributor.author","Stadelmann, Christine"],["dc.contributor.author","Hartmann, Christian"],["dc.contributor.editor","Hjelmeland, Anita B."],["dc.date.accessioned","2021-04-14T08:27:01Z"],["dc.date.available","2021-04-14T08:27:01Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1371/journal.pone.0229274"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/82143"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation.eissn","1932-6203"],["dc.title","Expression of Olig2, Nestin, NogoA and AQP4 have no impact on overall survival in IDH-wildtype glioblastoma"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","213"],["dc.bibliographiccitation.journal","BMC Cancer"],["dc.bibliographiccitation.volume","14"],["dc.contributor.author","Martinez, Ramon"],["dc.contributor.author","Carmona, F. Javier"],["dc.contributor.author","Vizoso, Miguel"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Kirsch, Matthias"],["dc.contributor.author","Schackert, Gabriele"],["dc.contributor.author","Ropero, Santiago"],["dc.contributor.author","Paulus, Werner"],["dc.contributor.author","Barrantes, Alonso"],["dc.contributor.author","Gomez, Antonio"],["dc.contributor.author","Esteller, Manel"],["dc.date.accessioned","2018-11-07T09:42:29Z"],["dc.date.available","2018-11-07T09:42:29Z"],["dc.date.issued","2014"],["dc.description.abstract","Background: Pleomorphic xanthoastrocytoma (PXA) is a rare WHO grade II tumor accounting for less than 1% of all astrocytomas. Malignant transformation into PXA with anaplastic features, is unusual and correlates with poorer outcome of the patients. Methods: Using a DNA methylation custom array, we have quantified the DNA methylation level on the promoter sequence of 807 cancer-related genes of WHO grade II (n = 11) and III PXA (n = 2) and compared to normal brain tissue (n = 10) and glioblastoma (n = 87) samples. DNA methylation levels were further confirmed on independent samples by pyrosequencing of the promoter sequences. Results: Increasing DNA promoter hypermethylation events were observed in anaplastic PXA as compared with grade II samples. We further validated differential hypermethylation of CD81, HCK, HOXA5, ASCL2 and TES on anaplastic PXA and grade II tumors. Moreover, these epigenetic alterations overlap those described in glioblastoma patients, suggesting common mechanisms of tumorigenesis. Conclusions: Even taking into consideration the small size of our patient populations, our data strongly suggest that epigenome wide profiling of PXA is a valuable tool to identify methylated genes, which may play a role in the malignant progression of PXA. These methylation alterations may provide useful biomarkers for decision-making in those patients with low-grade PXA displaying a high risk of malignant transformation."],["dc.description.sponsorship","Cellex Foundation (Spain); ICREA"],["dc.identifier.doi","10.1186/1471-2407-14-213"],["dc.identifier.isi","000334533400001"],["dc.identifier.pmid","24650279"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10070"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33963"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Biomed Central Ltd"],["dc.relation.issn","1471-2407"],["dc.rights","CC BY 2.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/2.0"],["dc.title","DNA methylation alterations in grade II- and anaplastic pleomorphic xanthoastrocytoma"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","29254"],["dc.bibliographiccitation.issue","30"],["dc.bibliographiccitation.journal","Oncotarget"],["dc.bibliographiccitation.lastpage","29267"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Siam, Laila"],["dc.contributor.author","Bleckmann, Annalen"],["dc.contributor.author","Chaung, Han-Ning"],["dc.contributor.author","Mohr, Alexander"],["dc.contributor.author","Klemm, Florian"],["dc.contributor.author","Barrantes-Freer, Alonso"],["dc.contributor.author","Blazquez, Raquel"],["dc.contributor.author","Wolff, Hendrik Andreas"],["dc.contributor.author","Lueke, Florian"],["dc.contributor.author","Rohde, Veit"],["dc.contributor.author","Stadelmann, Christine"],["dc.contributor.author","Pukrop, Tobias"],["dc.date.accessioned","2018-11-07T09:50:20Z"],["dc.date.available","2018-11-07T09:50:20Z"],["dc.date.issued","2015"],["dc.description.abstract","The current approach to brain metastases resection is macroscopic removal of metastasis until reaching the glial pseudo-capsule (gross total resection (GTR)). However, autopsy studies demonstrated infiltrating metastatic cells into the parenchyma at the metastasis/brain parenchyma (M/BP)-interface. Aims/Methods: To analyze the astrocyte reaction and metastatic infiltration pattern at the M/BP-interface with an organotypic brain slice coculture system. Secondly, to evaluate the significance of infiltrating metastatic tumor cells in a prospective biopsy study. Therefore, after GTR, biopsies were obtained from the brain parenchyma beyond the glial pseudo-capsule and analyzed histomorphologically. Results: The coculture revealed three types of cancer cell infiltration. Interestingly, the astrocyte reaction was significantly different in the coculture with a benign, neuroectodermal-derived cell line. In the prospective biopsy study 58/167 (34.7%) samples revealed infiltrating metastatic cells. Altogether, 25/39 patients (64.1%) had proven to exhibit infiltration in at least one biopsy specimen with significant impact on survival (OS) (3.4 HR; p = 0.009; 2-year OS was 6.6% versus 43.5%). Exceptionally, in the non-infiltrating cohort three patients were long-term survivors. Conclusions: Metastatic infiltration has a significant impact on prognosis. Secondly, the astrocyte reaction at the M/BP-interface is heterogeneous and supports our previous concept of the organ-specific defense against metastatic (organ-foreign) cells."],["dc.identifier.doi","10.18632/oncotarget.4201"],["dc.identifier.isi","000363183200062"],["dc.identifier.pmid","26299612"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13618"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35687"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Impact Journals Llc"],["dc.relation.issn","1949-2553"],["dc.rights","CC BY 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/3.0"],["dc.title","The metastatic infiltration at the metastasis/brain parenchyma-interface is very heterogeneous and has a significant impact on survival in a prospective study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]