Semen Onder
Istanbul University
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Publication
Featured researches published by Semen Onder.
Diabetes Research and Clinical Practice | 2014
Fatih Bal; Seldag Bekpinar; Yesim Unlucerci; Zeynep Kusku-Kiraz; Semen Onder; Müjdat Uysal; Figen Gurdol
AIMS We aimed to investigate the pharmacological efficiency of metformin on asymmetric dimethylarginine (ADMA) metabolism in inflammation caused by the lipopolysaccharide (LPS)/D-galactosamine (D-GalN) treatment. METHODS Adult Sprague-Dawley rats were injected LPS/D-GalN intraperitoneally. One half of the animals was injected metformin (250 mg kg(-1) body mass for one week) prior to LPS/D-GalN treatment. Six hours after the LPS/D-GalN injection, livers were removed, and used for the measurements of dimethylarginine dimethylaminohydrolase (DDAH) and myeloperoxidase (MPO) activities, glutathione (GSH), ADMA and arginine levels. Liver tissues were examined histopathologically. The Kruskal-Wallis (posthoc Mann-Whitney U) test was used for the statistics. LPS/D-GalN injections caused liver injury as evidenced by the activities of aminotransferases and arginase. GSH level and DDAH activity were decreased in the liver. Metformin pretreatment alleviated the activity of serum enzymes, and attenuated histopathological lesions caused by LPS/D-GalN injections. LPS/D-GalN-induced inflammation, as confirmed by the increased MPO activity, created an asymmetrical distribution of arginine and ADMA between the tissue and plasma. Metformin decreased tissue ADMA level while it restored the DDAH activity and GSH. CONCLUSION Our findings showed that metformin administration for one week has a potency to protect liver through regulating ADMA metabolism in LPS/D-GalN-induced injury.
Endocrine Pathology | 2016
Ozturk Sari S; Taskin Oc; Gundogdu G; Gulcin Yegen; Semen Onder; Keskin M; Saglam S; Ozluk Y; Gulluoglu M; Ozgur Mete
This study investigated the impact of phosphohistone-H3 (PHH3)-assisted mitotic count by comparing its performance with conventional mitotic count and Ki67 score as well as the status of distant metastasis. A total of 43 surgically resected pancreatic neuroendocrine tumors (panNET) with complete follow-up information has been subjected to a standardized assessment with respect to mitotic count (both conventional and PHH3-assisted) and Ki67 score. Five participants assessed mitotic count and the time spent was recorded in both methods. All tumors were assigned to a G1 category of mitotic rate on conventional mitotic count that failed to identify three tumors with a G2 category of mitotic rate on PHH3. Near-perfect and fair agreements were achieved among observers when using PHH3 and conventional method, respectively. The mean time spent to determine mitotic count on PHH3-stained slides was significantly shorter (p < 0.001). The performance of PHH3-assisted mitotic grade category was significant as the three cases with a G2 mitotic category were associated with distant metastasis (p = 0.01). Despite its performance, the PHH3-assisted mitotic count downgraded 17 cases that were classified as G2 based on Ki67 scores in this series. The Ki67 grade category was either the same or higher than the mitotic grade category. Ten patients developed distant metastasis. Eleven tumors exhibited vascular invasion characterized by intravascular tumor cells admixed with thrombus. Our results indicate that PHH3-assisted mitotic count facilitates an accurate mitotic count with a perfect agreement among observers. The small size of this cohort is an important limitation of the current study, a G2 mitotic grade category based on PHH3 immunohistochemistry was one of the correlates of panNETs with distant metastasis. While the prognostic impact of PHH3-assisted mitotic count needs to be clarified in larger cohorts, Ki67 scores designated higher grade category in all cases; thus, it was the best determinant of the tumor grade. More importantly, the presence of vascular invasion along with the Ki67 grade category was found to be independent predictors of distant metastasis.
International Journal of Surgical Pathology | 2015
Gulcin Yegen; Mine Gulluoglu; Ozgur Mete; Semen Onder; Yersu Kapran
Clear cell sarcoma is a rare tumor classically associated with tendons and aponeuroses of lower extremities of young adults and has a distinctive histopathologic and molecular profile. It has been rarely described in other locations other than soft tissues, including the gastrointestinal tract. Herein we report a case of clear cell sarcoma of gastrointestinal tract arising in the ileum, which is rich in osteoclast-like giant cells with a review of the literature.
Medicine | 2015
Adnan Aydiner; Fatma Sen; Makbule Tambas; Rumeysa Ciftci; Yesim Eralp; Pinar Saip; Hasan Karanlik; Merdan Fayda; Seden Kucucuk; Semen Onder; Ekrem Yavuz; Mahmut Muslumanoglu; Abdullah Igci
AbstractMetaplastic breast carcinoma (MBC) differs from classic invasive ductal carcinomas regarding incidence, pathogenesis, and prognosis. The purpose of this study was to compare patients with MBC with clinicopathologic and treatment-matched patients with triple-negative breast carcinoma (TNBC) in terms of response to treatment, progression, and survival.Fifty-four patients with MBC and 51 with TNBC, who were treated at Istanbul University, Institute of Oncology, between 1993 and 2014, were included in the study. After correctly matching the patients with 1 of the 2 groups, they were compared to determine differences in response to treatment, disease progression, clinical course, and survival.At a median follow-up of 28 months, 18 patients (17.1%) died and 27 (25.5%) had disease progression. Metaplastic histology was significantly correlated with worse 3-year progression-free survival (PFS) (51 ± 9% vs. 82 ± 6%, P = 0.013) and overall survival (OS) (68 ± 8% vs. 94 ± 4%, P = 0.009) compared with TNBC histology. Patients who received taxane-based chemotherapy (CT) regimens or adjuvant radiotherapy had significantly better PFS (P = 0.002 and P < 0.001) and OS (P < 0.001 and P < 0.001) compared with others. In the multivariate analysis, MBC (hazard ratio [HR]: 0.09, P < 0.001), presence of neoadjuvant chemotherapy (NACT) (HR: 12.8, P = 0.05), and metastasis development at any time during the clinical course (HR: 38.7, P < 0.001) were significant factors that decreased PFS, whereas metastasis development was the only independent prognostic factor of OS (HR: 23.8, P = 0.009).MBC is significantly correlated with worse PFS and OS compared with TNBC. Patients with MBC are resistant to conventional CT agents, and more efficient treatment regimens are required.
Insights Into Imaging | 2013
Mehmet Ruhi Onur; Ahmet Kursad Poyraz; Pinar Gundogan Bozdag; Semen Onder; Cem Aygun
ObjectiveTo investigate the utility of apparent diffusion coefficient (ADC) measurement in the diagnosis of chronic viral hepatitis (CVH) and correlation between ADC values and histopathologic severity of CVH.Materials and methodsThe ADC values of liver parenchyma on diffusion-weighted magnetic resonance imaging (DWMRI) were measured in 50 patients with a history of CVH and 51 healthy subjects at b 100, b 600 and b 1,000 gradients. Comparison between mean ADC values of the CVH and control groups and correlation results between ADC values and necroinflammation and fibrosis scores in CVH were obtained.ResultsMean ADC values of CVH patients were significantly lower than mean ADC values of the control group at b 100 and b 600 gradients (P < 0.05). There was no significant difference between the CVH and control groups at the b 1,000 gradient (P > 0.05). No significant correlation was found between ADC values and histopathologic scores of CVH (P > 0.05).ConclusionADC values obtained at the b 100 and b 600 gradients can be used to distinguish between the liver parenchyma of CVH and healthy subjects. ADC measurement was not found to be useful for estimation of the degree of necroinflammation and fibrosis in CVH.Teaching Points• In chronic viral hepatitis apparent coefficient values are decreased in the liver• There is no correlation between ADC values and histopathologic severity of CVH• DW images obtained at low b values have more ability to demonstrate an ADC decrease in viral hepatitis
Journal of Pediatric Gastroenterology and Nutrition | 2011
Ayşen Aydoğan; Mine Gulluoglu; Semen Onder; Selim Gökçe; Coşkun Çeltik; Özlem Durmaz
Objectives:The aim of the study was to determine the frequency of portal gastropathy (PG) and duodenopathy (PD) in children, to document the correlation of various clinical and laboratory parameters associated with portal hypertensive gastroduodenal lesions, to compare the endoscopic portal hypertensive lesions with different histologic findings, and to evaluate the use of a possible histologic scoring system. Methods:All children undergoing endoscopic investigation for portal hypertension (PH) between January 2006 and November 2007 were analysed retrospectively. Clinical and demographical data and endoscopic and histologic findings were recorded. Histologic findings suggestive of PG and PD (capillary dilation, increased numbers of capillaries, histologic bleeding, and edema) were scored. Results:Of 51 consecutive children (29 boys, mean age 10.1± 3.6 years [range 2.5–15.8 years]), 28 were cirrhotic. PG was diagnosed in 58.8% endoscopically. Children with cirrhotic PH had the highest rate of PG (64.3%), whereas those with extrahepatic or intrahepatic noncirrhotic PH were alike (50% and 54.5%, respectively). Baveno PG scores were higher in children with cirrhosis with higher Child-Pugh scores. Capillary dilation was the only histologic finding showing significant association with the endoscopic diagnosis. Only 9% had PD on endoscopy. None of the histologic findings correlated with endoscopic diagnosis of PD. Conclusions:PG and PD are seen in children with extrahepatic and intrahepatic PH at rates similar to those reported in adult studies. Baveno PG scores increased in parallel with Child-Pugh class in children with cirrhosis. Capillary dilation was the only histologic finding showing significant association with the endoscopic diagnosis of PG in this study.
International Journal of Surgical Pathology | 2015
Mine Gulluoglu; Gulcin Yegen; Yasemin Ozluk; Metin Keskin; Serap Dogan; Gokcen Gundogdu; Semen Onder; Emre Balik
Background. The most important prognostic factor for early gastric cancer (EGC) is the lymph node status. It is important to predict early lesions without lymph node metastasis (LNM) before proceeding to radical surgery in locally excised lesions. Tumor budding is a feature known to be related to aggressive tumor behavior in several solid tumors. We aimed to assess the predictive value of tumor budding for LNM in pT1a and pT1b gastric cancer. Methods. We retrospectively investigated radical gastrectomy specimens for of 126 EGC patients and assess the possible relation between the clinicopathologic features, including age, gender, tumor location, tumor size, macroscopic tumor type, histologic differentiation, depth and width of submucosal invasion, lymphovascular invasion, and tumor budding with lymph node involvement. Results. Among the 126 EGCs, 38 were stages as pT1a and 88 as pT1b. LNM rate in pT1a tumors was 13% whereas it was 33% in pT1b tumors. Tumor budding was the only factor significantly and independently related to LNM in pT1a patients. Female gender and tumor budding were found to be independent risk factors in pT1b group. Other clinicopathologic features were not related to LNM. Conclusion. Based on these results, we suggest that budding is a promising parameter to assess for prediction of LNM in EGC removed by endoscopic surgery, and to decide on the appropriate surgical approach.
Ejso | 2015
Hasan Karanlik; I. Ozgur; Neslihan Cabioglu; Fatma Sen; K. Erturk; Berkay Kilic; Semen Onder; M. Deniz; Ekrem Yavuz; Adnan Aydiner
BACKGROUND The aim of this study is to compare the clinical outcome in T2 breast cancer patients who underwent preoperative chemotherapy (PC) and who did not. The study also tried to define a subgroup of patients, who are more beneficial after PC in terms of lower re-excision rates, better cosmetic results and local recurrence free survival. MATERIALS AND METHODS 251 consecutive patients treated for nonmetastatic T2 invasive breast cancer were analyzed retrospectively. Of those; 141 underwent primary surgery (PS) followed by chemotherapy, whereas 110 were treated with combination of PC and surgery. RESULTS The patients who were treated with PC had a significantly higher incidence of negative margins and lower rate of re-excision (5% vs. 16%, p = 0.02). Of all patients attempted breast conserving surgery (BCS), patients in the PC group were more likely to undergo BCS as their definitive operation compared to patients with PS group (BCS rates; PC group: 99% vs. PS group: 92%, p = 0.05). Multifocal disease (OR: 7, 95% Cl, 2.7-18.4, p = 0.0001) and PC (OR = 0.2; 95% CI, 0.06-0.72, p = 0.01) were factors associated with margin positivity in patients treated with BCS. There was no statistically significant difference in 5 year local-recurrence free survival rates between 2 groups. CONCLUSIONS Our study shows that PC significantly decreases the re-excision in patients undergoing BCS with primary T2 breast tumors. This data suggests that any patient with a tumor greater than 2 cm might be considered for PC to increase BCS success with final negative margins.
Journal of Surgical Oncology | 2016
Hasan Karanlik; Ilker Ozgur; Berkay Kilic; Alisan Fathalizadeh; Yasemin Sanli; Semen Onder; Pinar Saip; Fatma Sen; Bahadir M. Gulluoglu
It is not clear whether sentinel lymph node biopsy (SLNB) can be applied to patients with a second breast cancer or recurrence occurring at previously treated breast. The purpose of this study was to assess the feasibility of SLNB procedure in patients with recurrent breast cancer.
Journal of Cancer Research and Therapeutics | 2015
Faruk Tas; Senem Karabulut; Gulcin Yegen; Semen Onder; Rumeysa Ciftci
Malignant melanoma may metastasize to virtually any organs. Metastases to the oral cavity are uncommon and tongue metastases are very rare. The patient was a 79-year-old woman with cutaneous malignant melanoma. Lesion was widely excised and lymph node dissection was performed. She also had adjuvant chemotherapy. She is the unique malignant melanoma case who had recurrence on tongue 10 years later in literature. In conclusion, the prognosis of patients with tongue metastasis is poor and most of these patients have underlying widespread diseases.