0000000000722818
AUTHOR
Dimitrios Koutsimpelas
showing 8 related works from this author
Cholesteatoma of the hypotympanum in a patient with Treacher Collins syndrome
2014
In the present article we report a cholesteatoma of the hypotympanum extending to the jugular foramen in a 16-year-old male with Treacher Collins syndrome. Preoperative imaging excluded jugular paraganglioma and set the diagnosis of cholesteatoma. We discuss the operative treatment via a large hypotympanotomy and creation of an open hypotympanic cavity. To the authors' knowledge this is the first description of hypotympanal cholesteatoma with such an extension, being treated through this approach.
The VEGF/VEGF-R Axis in Sporadic Vestibular Schwannomas Correlates with Irradiation and Disease Recurrence
2012
<b><i>Background/Aims:</i></b> The molecular mechanisms downstream of mutated neurofibromatosis type 2 (NF2) gene resulting in the growth and development of vestibular schwannoma (VS) are controversial. Several lines of evidence suggest the involvement of the vascular endothelial growth factor (VEGF) pathway in VS development. Given that recent studies of VEGF blockade in patients with NF2-associated VS showed positive effects on VS growth control, we initiated this comprehensive study of the VEGF pathway in sporadic VS. <b><i>Methods:</i></b> A tissue microarray analysis of 182 sporadic VS was conducted. The expression of VEGF and its recepto…
Promoter methylation of MGMT, MLH1 and RASSF1A tumor suppressor genes in head and neck squamous cell carcinoma: Pharmacological genome demethylation …
2012
Promoter hypermethylation of tumor suppressor genes (TSGs) is a common feature of primary cancer cells. However, to date the somatic epigenetic events that occur in head and neck squamous cell carcinoma (HNSCC) tumorigenesis have not been well-defined. In the present study, we analyzed the promoter methylation status of the genes mutL homolog 1 (MLH1), Ras-association domain family member 1 (RASSF1A) and O-6-methylguanine-DNA methyltransferase (MGMT) in 23 HNSCC samples, three control tissues and one HNSCC cell line (UM-SCC 33) using methylation-specific PCR (MSP). The expression of the three proteins was quantified by semi-quantitative immunohistochemical analysis. The cell line was treate…
Pharmacological genome demethylation increases radiosensitivity of head and neck squamous carcinoma cells
2011
Aberrant inactivation of tumor suppressor genes by promoter hypermethylation has been recognized as a crucial step of tumor development and is related to aggressiveness and therapy resistance. To identify potential novel treatment strategies, we evaluated pharmacological genome demethylation for the increase of irradiation treatment effectiveness in head and neck squamous cell carcinoma (HNSCC) in this in vitro study. HNSCC cells were cultured with 2 different concentrations of 5-azacytidine (5-Aza) for 72 h, followed by a single fraction irradiation with 4 or 50 Gy, respectively. To show successful genome demethylation, the methylation status of the tumor suppressor gene hic1 (hypermethyla…
Lack of neurofibromatosis type 2 gene promoter methylation in sporadic vestibular schwannomas.
2011
<i>Background:</i> Vestibular schwannomas (VS) are benign tumors of the nervous system that are usually sporadic but also occur in the inherited disorder neurofibromatosis type 2 (NF2). In VS, losses of chromosomal material and mutations of the NF2 gene have been established to be causative. For a subset of VS without detectable gene alterations, promoter inactivation by hypermethylation has been suggested. However, published data are very limited and contradictory. <i>Methods:</i> We analyzed NF2 gene promoter methylation in 35 sporadic VS by methylation-specific PCR. <i>Results:</i> Twenty-three of the tumors were informative, showing no promoter methyl…
Increased basic fibroblast growth factor release and proliferation in xenotransplanted squamous cell carcinoma after combined irradiation/anti-vascul…
2012
Novel strategies of cancer therapy combine irradiation and anti-angiogenic active compounds. However, little is known concerning the undesired cellular and molecular effects caused by this novel treatment concept. We used a mouse squamous cell carcinoma (SCC) xenotransplantation model to evaluate the potential undesired effects which compromise the success of this therapeutic combination. SCCs were subcutanously implanted in nude mice. Animals were treated with a fractionated irradiation scheme (5x4 Gy) alone or in combination with daily injections of anti-vascular endothelial growth factor (VEGF) antibodies. Controls remained untreated. Before and after treatment, resonance imaging (MRI), …
Multifocal adult rhabdomyoma of the head and neck: a case report and literature review.
2008
Adult rhabdomyoma is a rare, usually solitary, primary tumour of striated muscle origin that almost exclusively presents in the head and neck region with predilection for male. We herein present a rare case of a multifocal adult rhabdomyoma in a 72-year-old woman. The lesions were located, the first one in the area of the left aryepiglottic fold and the second one right cervical arising from oesophagus. The diagnosis of the cervical mass was obtained prior to resection through cytological examination (FNAC). We discuss the clinical, cytological and histological findings and we provide a brief review of the literature on this entity.
Low SPINK5 expression in chronic rhinosinusitis
2012
Objectives/Hypothesis: Chronic rhinosinusitis (CRS) is a multifactorial disease that probably arises as a result of genetic diversity and environmental factors. SPINK5 is a serine protease inhibitor, which is supposed to be an important regulator of epithelial barrier maintenance. The role of SPINK5 polymorphisms and expression in CRS, especially in individuals with aspirin intolerance, is unclear. Study Design: SPINK5 single-nucleotide polymorphisms (SNPs) and SPINK5 expression levels were correlated with CRS without (CRSsNP) and with nasal polyps (CRSwNP), aspirin intolerance, asthma, and allergies. Methods: One hundred four nasal tissue samples, 15 from patients with CRSsNP, 59 from pati…