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KÖKER, İBRAHİM HAKKI

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İBRAHİM HAKKI
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KÖKER
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    PublicationOpen Access
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    PublicationOpen Access
    Pancreas cyst fluid viscocity assesment in the diagnosis of mucinous cyts
    (2018-06-01T00:00:00Z) KÖKER, İBRAHİM HAKKI; ŞENTÜRK, HAKAN; KÖKER, İBRAHİM HAKKI; ŞENTÜRK, HAKAN
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    PublicationOpen Access
    Can serum histone H4 levels predict mucosal healing in Crohn-s disease?
    (2021-01-01T00:00:00Z) KÖKER, İBRAHİM HAKKI; SÜMBÜL, BİLGE; KİREMİTÇİ, SERCAN; KOÇHAN, KORAY; İNCE, ALİ TÜZÜN; BİBERCİ KESKİN, Elmas; ŞENTÜRK, HAKAN; KÖKER, İBRAHİM HAKKI; SÜMBÜL, BİLGE; KİREMİTÇİ, SERCAN; KOÇHAN, KORAY; İNCE, ALİ TÜZÜN; BİBERCİ KESKİN, ELMAS; ŞENTÜRK, HAKAN
    Introduction: Mucosal healing (MH) has been a treatment target with the introduction of biological agents in Crohn's disease (CD). Histone H4 increases in chronic inflammation. Aim: Our goal was to investigate the role of serum histone H4 in predicting MH. Material and methods: The study included 44 patients who applied to the endoscopy unit for ileocolonoscopic evaluation with the diagnosis of ileocecal CD and 26 healthy controls. After ileocolonoscopic evaluation, we divided the patients into 2 groups: those with and those without MH, according to the presence of endoscopic ulcer or erosion findings. Blood samples were taken from these patients to analyse serum histone H4 before the endoscopic procedure. We first compared serum histone H4 levels between CD patients and the healthy control group and then between those with and those without MH among the CD patients. Finally, we compared CRP, ESR, and serum histone H4 levels in patients with CD according to the presence of MH and symptoms. Results: Serum histone H4 levels were significantly higher in ileocolonic CD patients compared to the healthy control group (p = 0.002). Also, serum histone H4 levels were significantly higher in CD patients with no MH (p = 0.028) or symptomatic patients (p = 0.033). We did not find a significant difference in C-reactive protein and erythrocyte sedimentation rate levels between CD patients in the presence of MH (p = 0.281 and p = 0.203, respectively) or symptoms (0.779 and 0.652, respectively). Conclusions: Serum histone H4 might be a useful biomarker for MH prediction in ileocolonoscopic CD patients. Validation is needed for large numbers of patients.
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    PublicationOpen Access
    Mucinous Pancreatic Cysts: Comparison of Cyst Size and Location in Certain Mucinous Cyst Subgroups
    (2021-09-01T00:00:00Z) KÖKER, İBRAHİM HAKKI; Elagoz, Sahende; GÜCİN, ZÜHAL; MALYA, FATMA ÜMİT; ŞENTÜRK, HAKAN; KÖKER, İBRAHİM HAKKI; GÜCİN, ZÜHAL; MALYA, FATMA ÜMİT; ŞENTÜRK, HAKAN
    Background: There are studies reporting that the location of intraductal papillary mucinous neoplasia (IPMN) predicts malignancy. Therefore, we evaluated the cyst location’s relationship with malignancy, and the possibility of using cyst size and location to distinguish between non-main duct (non-MD)-IPMNs, mucinous cystic neoplasia (MCN), and cystic pancreatic ductal adenocarcinoma (PDAC). Methods: We performed a retrospective analysis of data from 122 patients with a definite cyto-histological diagnosis of non-MDIPMNs, LR-MCNs, and cystic PDACs via endoscopic ultrasound fine-needle aspiration between October 2011 and October 2020. We grouped the cyst locations as head, uncinate, neck (HUN), and corpus or tail (CT). On histology, low-grade dysplasia and intermediategrade dysplasia were considered low risk (LR), whereas high-grade dysplasia and invasive carcinoma were considered high risk (HR). Results: Of the 122 patients (61 (50%) women, median age 61.5 years (range 19-85), there were 34 (27.9%) LR-non-MD-IPMNs, 33 (27%) HR-non-MD-IPMNs, 19 (15.6%) LR-MCNs, and 36 (29.5%) cystic PDACs. We found no significant difference between LRand HR-non-MD-IPMN locations (P = .803). Low-risk non-MD-IPMNs were significantly smaller than HR-non-MD-IPMNs (P < .001), LR-MCNs (P = .002), and cystic PDACs (P < .001). The area under the receiver operating characteristic curve (AUROC) was 0.819 (95% CI: 0.716-0.902; P < .0001), and demonstrated a cyst size cut-off <2.2 cm to differentiate LR cysts, while cysts <1.6 cm had a negative predictive value (NPV) of 100% in non-MD-IPMNs. Conclusion: Cyst location is not predictive of malignancy in non-MD-IPMNs. Low-risk non-MD-IPMNs were smaller than HR-non-MDIPMNs, LR-MCNs, and cystic PDACs. The cyst size cut-off was 2.2 cm; however, <1.6 cm had a 100% NPV differentiating LR- from HR-non-MD-IPMNs
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    PublicationOpen Access
    Mucin expression in mucinous pancreatic cysts: Can string sign test predict mucin types? A single center pilot study
    (2020-12-01T00:00:00Z) Köker, İbrahim Hakkı; Ünver, Nurcan; Malya, Fatma Ümit; Uysal, Ömer; Şentürk, Hakan; KÖKER, İBRAHİM HAKKI; MALYA, FATMA ÜMİT; BİBERCİ KESKİN, ELMAS; ŞENTÜRK, HAKAN
    Background: Mucinous pancreatic cystic lesions (PCLs) express different mucin (MUC) types according to their histomorphologic types. High cystic fluid viscosity may help in the detection of mucinous PCLs. We hypothesized that high cystic fluid viscosity may be suggestive of a certain MUC type in mucinous PCLs. Methods: Prespecified MUC types (MUC1, MUC2, MUC4, MUC5AC, and MUC6) were evaluated in 18 definitively diagnosed mucinous PCLs with sufficient tissue material and prediagnostic cyst fluid viscosity evaluation—string sign (SS)—test. We evaluated the agreement of MUC expression with positive SS test results. Later, we compared cystic fluid carcinoembryonic antigen (CEA) between the prespecified MUC expressing and nonexpressing cyst types. Results: A total of 18 mucinous PCL patients, 11 females, with mean age ± SD (59.7 ± 13.3) were included. Almost all malignant mucinous PCLs expressed MUC1 (71.4%) (P = .023). We found no significant agreement between the prespecified MUC types and positive SS, except MUC4 which had mild agreement. Also, no significant relation was found between cystic fluid CEA levels and MUC expression (P = .584). Conclusion: We did not detect a significantly moderate or good agreement between the prespecified MUC types and SS test. MUC1 was highly expressed in malignant mucinous cysts; however, it was incompatible with the SS test. MUC4 expression showed mild agreement with the SS test in a small number of patients
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    PublicationOpen Access
    The relationship of Serum Histone H3.3 and H4 with chronic Hepatitis B
    (2020-09-01T00:00:00Z) Sümbül, Bilge; Şentürk, Hakan; Köker, İbrahim Hakkı; Koçhan, Koray; İnce, Ali Tüzün; Biberci Keskin, Elmas; İNCE, ALİ TÜZÜN; BİBERCİ KESKİN, ELMAS; SÜMBÜL, BİLGE; KOÇHAN, KORAY; KÖKER, İBRAHİM HAKKI; ŞENTÜRK, HAKAN
    Objective: To determine the role of serum histone H3.3 and H4 in patients with chronic hepatitis B to explore any relationship between the two.Methods: The prospective controlled clinical pilot study was conducted in the Gastroenterology Clinic of Bezmialem Vakif University, Istanbul, Turkey, from January to October 2017, and comprised biopsy-proven patients with chronic hepatitis B and healthy controls. Demographics, hepatitis B virus deoxyribonucleic acid quantity, hepatitis B e-antigen, aspartate aminotransferase, alanine transaminase, international normalized ratio, total/direct bilirubin, albumin and thrombocyte counts as well as histological activity index and fibrosis scores were noted. Data was analysed using SPSS 22.Results: Of the 140 subjects, 70(50%) each were cases and controls. The overall mean age of the sample was 43.38±15.07 years (range: 18-70 years). There was positive correlation of histone H3.3 with hepatitis B virus deoxyribonucleic acid, aspartate aminotransferase, alanine transaminase and international normalized ratio levels. Histone H4 levels only correlated with hepatitis B virus deoxyribonucleic acid and international normalized ratio. Hepatitis B e-antigen positivity was present in 14(20%) of the cases.Conclusion: Histone H3.3 levels appeared to be associated with pathophysiological changes in chronic hepatitis B patients, suggesting that future treatments should target H3.3.Keywords: Histone H3.3, Histone H4, Extracellular histone, Chronic Hepatitis B, HBV.(JPMA 70: 1596; 2020)DOI:https://doi.org/10.5455/JPMA.19365
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    PublicationOpen Access
    Cyst Fluid Carcinoembryonic Antigen Level Difference between Mucinous Cystic Neoplasms and Intraductal Papillary Mucinous Neoplasms
    (2020-12-01T00:00:00Z) KÖKER, İBRAHİM HAKKI; Ünver, Nurcan; MALYA, FATMA ÜMİT; UYSAL, ÖMER; BİBERCİ KESKİN, ELMAS; ŞENTÜRK, HAKAN; KÖKER, İBRAHİM HAKKI; MALYA, FATMA ÜMİT; UYSAL, ÖMER; BİBERCİ KESKİN, ELMAS; ŞENTÜRK, HAKAN