Person: UYSAL, ÖMER
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Publication Metadata only Relationship between KRAS mutation and diffusion weighted imaging in colorectal liver metastases; Preliminary study.(2020-02-25T00:00:00Z) Türk, HM; Gültekin, MEHMET ALİ; Uysal, Ö; Beşiroğlu, M; Yilmaz, TF; Yurtsever, I; GÜLTEKİN, MEHMET ALİ; TÜRK, HACI MEHMET; TOPRAK, HÜSEYİN; YURTSEVER, İSMAİL; YILMAZ, TEMEL FATİH; SHARIFOV, RASUL; UYSAL, ÖMERPurpose: We aimed to investigate whether there are any differences in apparent diffusion coefficient (ADC) values obtained from colorectal liver metastases (CRLM) according to Kirsten rat sarcoma (KRAS) gene mutation status.Publication Open Access Association between human leukocyte antigen gene polymorphisms and multiple EPIYA-C repeats in gastrointestinal disorders.(2020-08-28T00:00:00Z) Saribas, S; Demiryas, S; Uysal, O; Yilmaz, E; Kepil, N; Demirci, M; Caliskan, R; Dinc, HARİKA ÖYKÜ; Akkus, S; Gareayaghi, N; Kirmusaoglu, S; Ozbey, D; Tokman, HB; Koksal, SS; Tasci, I; Kocazeybek, B; UYSAL, ÖMER; DİNÇ, HARİKA ÖYKÜBackground: Polymorphisms of human leukocyte antigen (HLA) genes are suggested to increase the risk of gastric cancer (GC). Aim: To investigate the HLA allele frequencies of patients with GC relative to a control group in terms of CagA+ multiple (≥ 2) EPIYA-C repeats. Methods: The patient group comprised 94 patients [44 GC and 50 duodenal ulcer (DU) patients], and the control group comprised 86 individuals [(50 non-ulcer dyspepsia patients and 36 people with asymptomatic Helicobacter pylori (H. pylori)]. Polymerase chain reaction was performed for the amplification of the H. pylori cagA gene and typing of EPIYA motifs. HLA sequence-specific oligonucleotide (SSO) typing was performed using Lifecodes SSO typing kits (HLA-A, HLA-B HLA-C, HLA-DRB1, and HLA-DQA1-B1 kits). Results: The comparison of GC cases in terms of CagA+ multiple (≥ 2) EPIYA-C repeats showed that only the HLA-DQB1*06 allele [odds ratio (OR): 0.37, P = 0.036] was significantly lower, but significance was lost after correction (Pc = 0.1845). The HLA-DQA1*01 allele had a high ratio in GC cases with multiple EPIYA-C repeats, but this was not significant in the univariate analysis. We compared allele frequencies in the DU cases alone and in GC and DU cases together using the same criterion, and none of the HLA alleles were significantly associated with GC or DU. Also, none of the alleles were detected as independent risk factors after the multivariate analysis. On the other hand, in a multivariate logistic regression with no discriminative criterion, HLA-DQA1*01 (OR = 1.848), HLA-DQB1*06 (OR = 1.821) and HLA-A*02 (OR = 1.579) alleles were detected as independent risk factors for GC and DU. Conclusion: None of the HLA alleles were detected as independent risk factors in terms of CagA+ multiple EPIYA-C repeats. However, HLA-DQA1*01, HLA-DQB1*0601, and HLA-A*2 were independent risk factors with no criterion in the multivariate analysis. We suggest that the association of these alleles with gastric malignancies is not specifically related to cagA and multiple EPIYA C repeats.Publication Metadata only Factors Associated with Insufficient Endometrial Sampling in Postmenopausal Women(2020-01-01T00:00:00Z) ATEŞ, SEDA; Karasu, Ayse Filiz Gokmen; ÇALI, HALİME; Soyman, Zeynep; UYSAL, ÖMER; ATEŞ, SEDA; ÇALI, HALİME; UYSAL, ÖMERAim: To assess the risk factors associated with high rate of insufficient endometrial sampling on endometrial biopsy in postmenopausal women.Publication Metadata only The effects of human amniotic membrane on silicone related capsule formation in rats.(2020-05-19T00:00:00Z) Akyürek, M; Orhan, E; Aydın, MŞ; Uysal, ÖMER; Karşıdağ, S; UYSAL, ÖMERPublication Open Access Co-infection relationship with Epstein-Barr virus in gastroduodenal diseases with Helicobacter Pylori. Quantitative PCR and EBNA-1 gene-based approach(2022-04-01T00:00:00Z) Akkus, S.; Gareayaghi, N.; Saribas, S.; Demiryas, S.; Ozbey, D.; Kepil, N.; Demirci, M.; Sarp, T. Ziver; DİNÇ, HARİKA ÖYKÜ; Akcin, R.; Uysal, O.; Bakar, M. Tugberk; Aygun, M. Talha; BAHAR TOKMAN, HRİSİ; Kocazeybek, B.; DİNÇ, HARİKA ÖYKÜ; UYSAL, ÖMERObjective: Helicobacter pylori (Hp) and Epstein-Barr virus (EBV) are involved in gastric cancer (GC) etiology. EBV/Hp co- infection was thought synergistically increase gastroduodenal disease occurence. We aimed to determine the presence of EBV/Hp co-infection in gastroduodenal diseases. Methods: The study group had 68 Hp (+) cases [25 GC, 13 IM (intestinal metaplasia), 30 PU (peptic ulcer)], and the control group had 40 NUD (non-ulcer dyspepsia) cases [20 Hp+, 20 Hp-]. EBV-DNA was detected by non-polymorphic EBNA-1 gene-based qPCR. EBV/EBNA-1 IgG levels were determined by quantitative and qualitative ELISA methods, respectively. Results: EBV-DNA positivity was 32% (8/25), 6.6% (2/30) and 5% (1/20) in GC, PU and NUD Hp (+) cases, respectively. There was a significant difference (p = 0.001) between GC (32%) and NUD Hp (+) (5%) cases in terms of EBV-DNA positivity. Mean EBV-DNA copy numbers were 6568.54 ± 20351, 30.60 ± 159.88 and 13.85 ± 61.93 for GC, PU, and NUD, respectively. In terms of the mean EBV-DNA copy number, a significant difference was found between the groups (p = 0.005). In terms of EBV/EBNA-1 IgG antibody positivity, no significant difference was found between GC and NUD cases (p = 0.248). EBV DNA positivity was found to be significant (odds ration [OR] = 26.71 (p=0.009, %95CI 2.286- 312.041) in multivariate logistic regression. Conclusioin: Although we had a small number of GC cases, it can be suggested that the estimated risk created by the synergistic effect based on the addition of EBV increased 26 times in the presence of Hp in GC.Publication Metadata only Association between polymorphisms in HLA-A, HLA-B, HLA-DR, and DQ genes from gastric cancer and duodenal ulcer patients and cagL among cagA-positive Helicobacter pylori strains: The first study in a Turkish population.(2020-03-13T00:00:00Z) Dınc, HO; Kocak, BT; Saribas, S; Demiryas, S; Yilmaz, E; Uysal, ÖMER; Kepil, N; Demirci, M; Akkus, S; Gülergün, R; Gareayaghi, N; Dağdeviren, HE; Ozbey, D; Dağ, HH; Tokman, HB; Tasci, I; Kocazeybek, B; UYSAL, ÖMER; DİNÇ, HARİKA ÖYKÜPublication Open Access Diffusion Tensor Imaging Features of the Auditory Pathways in Patients With Vestibular Schwannoma After Gamma Knife Radiosurgery(2021-03-01T00:00:00Z) ÇEŞME, DİLEK HACER; ALKAN, ALPAY; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; Alkan, Gokberk; KAYA, AHMET; MAYADAĞLI, Alpaslan; Akdur, Kerime; UYSAL, ÖMER; HATİBOĞLU, MUSTAFA AZİZ; ÇEŞME, DİLEK HACER; ALKAN, ALPAY; GÜLTEKİN, MEHMET ALİ; SARI, LÜTFULLAH; KAYA, AHMET; MAYADAĞLI, ALPASLAN; UYSAL, ÖMER; HATİBOĞLU, MUSTAFA AZİZObjective In this study, we aimed to investigate whether there is any change in diffusion tensor imaging (DTI) parameters in ipsilateral and contralateral auditory pathways after Gamma Knife radiosurgery (GKR) in patients with vestibular schwannoma (VS) and the relationship between radiosurgery variables. Methods Sixty-six patients were evaluated with MRI and DTI before and after GKR. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured from the bilateral lateral lemniscus (LL), inferior colliculus (IC), medial geniculate body (MGB), and Heschl's gyrus (HG). Results There was no significant difference in ADC and FA values obtained from bilateral LL, IC, and MGB before and after radiosurgery. However, there was a significant difference between pretreatment and post-radiosurgery contralateral HG ADC values. The ADC values obtained from the contralateral HG and IC positively correlated with the duration after radiosurgery. As the duration after radiosurgery increases, the difference between the ADC values obtained from ipsilateral and contralateral HG also increases. Conclusion The high ADC values in the contralateral HG after radiosurgery may indicate microstructural alterations such as demyelination and axonal loss. Radiation exposure doses to the brainstem and cochlea are the most important factors that can cause microstructural damage to the auditory pathways. When planning radiosurgery, extreme care should be taken to prevent the harmful effects of radiation on the auditory pathways.Publication Open Access Cyst Fluid Carcinoembryonic Antigen Level Difference between Mucinous Cystic Neoplasms and Intraductal Papillary Mucinous Neoplasms.(2020-12-11T00:00:00Z) Köker, İbrahim Hakkı; Ünver, Nurcan; Malya, Fatma Ümit; Uysal, Ömer; Keskin, Elmas Biberci; Şentürk, Hakan; MALYA, FATMA ÜMİT; UYSAL, ÖMER; BİBERCİ KESKİN, ELMAS; ŞENTÜRK, HAKANBackground/aims: The role of cyst fluid carcinoembryonic antigen (CEA) level in differentiating mucinous pancreatic cystic lesions (PCLs) is controversial. We investigated the role of cyst fluid CEA in differentiating low-risk (LR)-intraductal papillary mucinous neoplasms (IPMNs) from high-risk (HR)-IPMNs and LR-mucinous cystic neoplasms (MCNs). Methods: This was a retrospective study of 466 patients with PCLs who underwent endoscopic ultrasound-guided fine-needleaspiration over a 7-year period. On histology, low-grade dysplasia and intermediate-grade dysplasia were considered LR, whereas high-grade dysplasia and invasive carcinoma were considered HR. Results: Data on cyst fluid CEA levels were available for 50/102 mucinous PCLs with definitive diagnoses. The median CEA (range) levels were significantly higher in HR cysts than in LR cysts (2,624 [0.5-266,510] ng/mL vs. 100 [16.8-53,445]ng/mL, p=0.0012). The area under the receiver operating characteristic curve (AUROC) was 0.930 (95% confidence interval [CI], 0.5-0.8; p<0.001) for differentiating LR-IPMNs from LR-MCNs. The AUROC was 0.921 (95% CI, 0.823-1.000; p<0.001) for differentiating LR-IPMNs from HR-IPMNs. Both had a CEA cutoff level of >100ng/mL, with a negative predictive value (NPV) of 100%. Conclusion: Cyst fluid CEA levels significantly vary between LR-IPMNs, LR-MCNs, and HR-IPMNs. A CEA cutoff level of >100ng/mL had a 100% NPV in differentiating LR-IPMNs from LR-MCNs and HR-IPMNs.Publication Metadata only Factors Associated with Insufficient Endometrial Sampling in Postmenopausal Women(2020-01-01T00:00:00Z) ATEŞ, SEDA; GÖKMEN KARASU, AYŞE FİLİZ; ÇALI, HALİME; SOYMAN, ZEYNEP; UYSAL, ÖMER; ATEŞ, SEDA; GÖKMEN KARASU, AYŞE FİLİZ; ÇALI, HALİME; UYSAL, ÖMERPublication Metadata only Can PET-CT replace bone marrow biopsy for lymphoma staging? Retrospective analysis of 198 Hodgkin and non-Hodgkin lymphoma cases(2021-06-01T00:00:00Z) Güler, Beril; Adilli, Adila; Uysal, Ömer; GÜLER, BERIL; ERDOĞAN, EZGİ BAŞAK; UYSAL, ÖMERAim: Lymphoma staging is important from the prognostic and therapeutic point of view and bone marrow biopsy performed for this purpose makes up a large part of current hematopathology practice. PET-CT is the currently preferred method to evaluate bone marrow involvement by lymphoproliferative disorders as it is non-invasive and practical. The aim of this study was to compare trephine biopsy and PET-CT results as regards determining bone marrow involvement in various lymphoma subtypes. Materials and Methods: A total number of 198 bone marrow biopsies and 185 PET-CT images of cases consisting of various lymphoma subtypes were included in the study. The results of both methods evaluated for bone marrow infiltration were grouped as positive, negative, and suspicious to compare consistency. Statistical agreement was calculated with the kappa coefficient. The sensitivity, specificity, and the positive and negative predictive values were calculated as the diagnostic test measures. Results: Twenty-six cases (15.8%) had lymphoma involvement in trephine biopsies and 36 cases (21.2%) had positive findings for lymphoma involvement of the bone marrow on PET-CT. The two methods had weak statistical agreement (κ= 0.21). Biopsy and PETCT results were similar in 132 cases (71.20%). PET-CT showed false negative results in 11 cases in which infiltration was observed with biopsy. Twenty-six cases that were negative for lymphoma involvement on biopsy were accepted as positive on PET-CT and 16 of these cases were classical Hodgkin-s lymphoma. One case with suspicious bone marrow biopsy was positive on PET-CT, while four cases with suspicious PET-CT results were positive on biopsy. Conclusion: The results showed that both of the methods have advantages and disadvantages as regards lymphoma staging. However, histopathology is globally accepted as the gold standard for a definite diagnosis. We believe that the complementary use of the two methods is more beneficial for correct guidance during clinical practice.