Ahmet Coker
Ege University
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Featured researches published by Ahmet Coker.
Pathology Research and Practice | 2002
Ozgul Sagol; Burçin Tuna; Ahmet Coker; Sedat Karademir; Funda Obuz; Hüseyin Astarcıoğlu; Ali Küpelioğlu; Ibrahim Astarcioglu; Ömer Topalak
We investigated pS2 and HSP-70 protein expression in 36 pancreatic adenocarcinomas for their effect on disease extent and patient outcome. The cases were reviewed, histologically diagnosed, typed, graded, and staged. Lymphatic vessel, blood vessel and perineural invasion as well as lymph node, resection margin and adjacent organ involvements were re-evaluated. The standard streptavidin biotin immunperoxidase method was used for immunostaining with pS2 and HSP-70 antibodies. Cytoplasmic staining with both antibodies was scored semiquantitatively. The scores were compared with histopathological prognostic parameters using statistical methods. Standard prognostic parameters and staining scores were tested by survival analysis in terms of their effect on survival. All the tumors showed a positive cytoplasmic reaction with HSP-70 antibody. Seventy-seven percent of the tumors showed positive cytoplasmic staining with pS2 antibody (22.2% +, 13.9% ++ and 41.7% +++). There was a statistically significant difference between HSP-70 staining scores with N status and final stages of the tumors (Chi-square, p = 0.03 and p = 0.026, respectively), while neither direct nor inverse correlation was detected for both parameters. PS2 staining scores showed no statistically significant relationship with tumor grade T, M status, perineural invasion, lymph and blood vessel invasion. In tumors with extensive staining with pS2, tumor stage tended to be low (Chi square, p = 0.024, Kendall Tau-b, r: -0.336, p = 0.036). There was a statistically significant difference and inverse correlation between tumors with extensive pS2 staining and tumors with less intense staining in terms of lymph node metastasis (Chi-square, p = 0.041, Kendall Tau: p = 0.024, r = -0,373). In the R0 resection group, in univariate analysis, we found that with higher scores of HSP-70 staining, the prognosis of the patient tended to improve. (Cox regression, p = 0.013). In multivariate analysis, HSP-70 expression was found to be an independent prognostic factor. We found no relationship between pS2 staining and patient survival.
World Journal of Emergency Surgery | 2008
Unal Aydin; Pinar Yazici; Murat Zeytunlu; Ahmet Coker
Peri-hepatic packing procedure, which is the basic damage control technique for the treatment of hepatic hemorrhage, is one of the cornerstones of the surgical strategy for abdominal trauma. The purpose of this study was to evaluate the efficacy of the perihepatic packing procedure by comparing the outcomes of appropriately and inappropriately performed interventions. Trauma patients with liver injury were retrospectively evaluated. The patients who had undergone adequate packing were classified as Group A, and the patients who had undergone inappropriate packing, as Group B. Over a five-year period, nineteen patients underwent perihepatic packing. Thirteen of these patients were referred by other hospitals. Of 13 patients, 9 with inappropriate packing procedure due to insertion of intraabdominal drainage catheter (n=4) and underpacking (n=5) were evaluated in Group B, and the others (n=10) with adequate packing were assessed in Group A. Mean 3 units of blood were transfused in Group A and unpacking procedure was performed in the 24th hour. Only 3 (30%) patients required segment resection with homeostasis, and the mortality rate was 20% (2/10 patients). In Group B, 4 patients required repacking in the first 6 hrs. Mean 8 units of blood were transfused until unpacking procedure. The mortality rate was 44% (4/9 patients). The length of intensive care unit stay and requirement of blood transfusion were statistically significantly lower in Group A (p < 0.05). The mortality rate of this group was also lower. However, the difference between the groups for mortality rates was not statistically significant. This study emphasizes that efficacy of the procedure is one of the determinants that affects the results, and inadequate or inappropriate packing may easily result in poor outcome.
Transplantation | 2000
Hüseyin Astarcıoğlu; Sedat Karademir; Tarkan Unek; Erdener Özer; Menekay S; Ahmet Coker; Ibrahim Astarcioglu
BACKGROUND Pentoxifylline (PTX) pretreatment of recipients was shown to protect against liver graft failure from ischemia-reperfusion injury after orthotopic rat liver transplantation. It has also been shown that PTX protects against normothermic ischemia-reperfusion injury to the liver in lobar ischemia model in the rat. Whether PTX can benefit the liver procured from non-heart-beating donors (NHBDs) with up to 9 hr of cold ischemia is unknown. METHODS Donor and recipient rats were pretreated with intraperitoneal PTX (50 mg/kg) 1 hr before cardiac arrest and transplantation, respectively. Grafts were transplanted 0, 30, and 60 min after cardiac arrest with additional 1 and 9 hr of cold ischemia in both PTX-pretreated or untreated (control) groups (10 rats per group). PTX (25 mg/kg/day) was continuously given to the surviving rats for 5 days postoperatively. Recipient survival rates, serum enzyme levels, and histopathological examination of postreperfusion liver biopsies were all analyzed. RESULTS The survival rates, serum enzyme levels, and postreperfusion histology were significantly improved in groups pretreated with PTX compared to the controls. CONCLUSION Donor and recipient PTX pretreatment significantly improves the viability of the liver grafts procured from NHBDs.
Chemotherapy | 2004
Ilhan Oztop; Ugur Yilmaz; Tugba Yavuzsen; Arzu Yaren; Oktay Tarhan; Ozgul Sagol; Ahmet Coker; Mehmet Alakavuklar
Background: 5-Fluorouracil (5-FU) and gemcitabine are the major active drugs in the treatment of pancreatic cancer. Methods: Twenty-two patients with advanced pancreas cancer were treated with a new chemotherapy regimen consisting of infusional 5-FU and high-dose leucovorin with gemcitabine (GEMFUFOL). Results: A total of 200 cycles of chemotherapy were administered. The response rate was 27.3%, all responses being partial. The median survival time and 1-year survival rate were, respectively, 13 months and 60.4%. The toxicity was very low and severe hematological toxicity was exceptional. Conclusion: The GEMFUFOL regimen can be an active regimen for the treatment of advanced pancreatic cancer and has a low toxicity.
Virchows Archiv | 2009
Banu Yaman; Deniz Nart; Funda Yilmaz; Ahmet Coker; Murat Zeytunlu; Murat Kilic
Intrahepatic cholangiocarcinoma is subdivided as mass-forming, periductal-infiltrating, and intraductal-growing types. Intraductal-growing type is an entity described in recent years as mucin-producing intrahepatic cholangiocarcinoma or intrahepatic (biliary) intraductal papillary mucinous neoplasia (b-IPMN). b-IPMN is classified as adenoma, borderline tumor, carcinoma in situ, and carcinoma, from benign to malignant. Using a different classification, b-IPMNs are subdivided into intestinal, pancreatobiliary, gastric, or oncocytic based on morphology of the cells forming the lesion and expression of MUC1, MUC2, and MUC5 gene proteins in the mucin family. The clinical and histopathological features of b-IPMN diagnosed in three cases are presented herein. Case 1 was classified as borderline. Case 2 was diagnosed as carcinoma in situ. Case 3 had large invasive areas, and was diagnosed as carcinoma. In all three cases, immunohistochemical investigation revealed MUC1 and MUC5AC to be positive, and MUC2 to be negative. We present herein three cases diagnosed with the clinical and pathological findings of a new entity in the literature, b-IPMN, and we discuss the macroscopic, histological, and immunohistochemical features.
Journal of Medical Case Reports | 2009
Unal Aydin; Pinar Yazici; Fatih Tekin; Omer Ozutemiz; Ahmet Coker
IntroductionBronchobiliary fistula is an uncommon complication secondary to hepatobiliary surgery. Bilioptysis is a pathognomic finding for bronchobiliary fistulas. Diagnosis may be easily established in the light of clinical history, which can be aided by imaging studies to pinpoint the exact location. Some diagnostic procedures such as endoscopic retrograde cholangiopancreatectomy are also useful for treatment.Case presentationWe present three Turkish patients with bronchobiliary fistula secondary to previous hepatic surgery due to hydatid cyst in two, a 19-year-old and a 47-year-old man, and iatrogenic trauma of the common bile duct by endoscopy in a 35-year-old man. All of the patients were successfully treated by minimally invasive methods including percutaneous drainage and endoscopic retrograde cholangiopancreatography.ConclusionWe suggest that bronchobiliary fistula could be managed through conservative treatment methods which do not require in-hospital follow-up, particularly in uncomplicated cases. Otherwise, surgical management can be unavoidable.
Hepatobiliary & Pancreatic Diseases International | 2016
Ender Gunes Yegin; Erkan Oymaci; Emrah Karatay; Ahmet Coker
BACKGROUND Hepatocellular carcinoma (HCC) is a complex and heterogeneous malignancy, frequently occurs in the setting of a chronically diseased organ, with multiple confounding factors making its management challenging. HCC represents one of the leading causes of cancer-related mortality globally with a rising trend of incidence in some of the developed countries, which indicates the need for better surgical and nonsurgical management strategies. DATA SOURCES PubMed database was searched for relevant articles in English on the issue of HCC management. RESULTS Surgical resection represents a potentially curative option for appropriate candidates with tumors detected at earlier stages and with well-preserved liver function. The long-term outcome of surgery is impaired by a high rate of recurrence. Surgical approaches are being challenged by local ablative therapies such as radiofrequency ablation and microwave ablation in selected patients. Liver transplantation offers potential cure for HCC and also correction of underlying liver disease, and minimizes the risk of recurrence, but is reserved for patients within a set of criteria proposed for a prudent allocation in the shortage of donor organs. Transcatheter locoregional therapies have become the palliative standard allowing local control for intermediate stage patients with noninvasive multinodular or large HCC who are beyond the potentially curative options. The significant survival benefit with the multikinase inhibitor sorafenib for advanced HCC has shifted the direction of research regarding systemic treatment toward molecular therapies targeting the disregulated pathways of hepatocarcinogenesis. Potential benefit is suggested from simultaneous or sequential multimodal therapies, and optimal combinations are being investigated. Despite the striking progress in preclinical studies of HCC immunotherapy and gene therapy, extensive clinical trials are required to achieve successful clinical applications of these innovative approaches. CONCLUSION Treatment decisions have become increasingly complex for HCC with the availability of multiple surgical and nonsurgical therapeutic options and require a comprehensive, multidisciplinary approach.
World Journal of Emergency Surgery | 2009
Mircelal Kazimi; Murat Ulas; Cem Ibis; Mutlu Unver; Nazan Özsan; Funda Yilmaz; Galip Ersoz; Murat Zeytunlu; Murat Kilic; Ahmet Coker
Lower gastrointestinal hemorrhage accounts for approximately 20% of gastrointestinal hemorrhage. The most common causes of lower gastrointestinal hemorrhage in adults are diverticular disease, inflammatory bowel disease, benign anorectal diseases, intestinal neoplasias, coagulopathies and arterio-venous malformations. Hemangiomas of gastrointestinal tract are rare. Mesenteric hemangiomas are also extremely rare.We present a 25-year-old female who was admitted to the emergency room with recurrent lower gastrointestinal bleeding. An intraluminal bleeding mass inside the small intestinal segment was detected during explorative laparotomy as the cause of the recurrent lower gastrointestinal bleeding. After partial resection of small bowel segment, the histopathologic examination revealed a cavernous hemagioma of mesenteric origin.Although rare, gastrointestinal hemangioma should be thought in differential diagnosis as a cause of recurrent lower gastrointestinal bleeding.
Anz Journal of Surgery | 2006
Murat Aynaci; Pars Tunçyürek; Deniz Nart; Murat Zeytunlu; Omer Ozutemiz; Galip Ersoz; Funda Yilmaz; Jens Mayer; Ahmet Coker
Background: Matrix metalloproteinases (MMP) modulate end‐organ complications of acute pancreatitis, but the correlation between increased MMP production and histological severity of disease remains unclear. We examined the role of MMP and pancreas histology on experimental acute pancreatitis.
Central European Journal of Medicine | 2010
Savas Yakan; Safak Oztürk; Mustafa Harman; Oktay Tekesin; Ahmet Coker
Gossypiboma (retained surgical sponge) is a pseudotumor within the body that is composed of non-absorbable surgical material with a cotton matrix. Because the symptoms of gossypiboma usually are nonspecific and may appear years after surgery, the diagnosis of gossypiboma may be difficult because the condition may mimic a benign or malignant soft-tissue tumour in the abdomen and pelvis. A 61-year-old woman with a one-year history of left upper-quadrant pain and weight loss was referred to our center. She had undergone peptic ulcer perforation 23 year ago. Physical examination revealed dullness and palpable mass in the left upper abdomen. On examination by computed tomography (CT), a hypodense mass of 12 cm in diameter between the greater curvature of the stomach, pancreas, and splenic hilus was detected. Upon exploration, a mass lesion of 10 cm in diameter was detected between the greater curvature of the stomach and splenic hilus, which caused dense adhesions not in communication with the pancreas. It was excised and a splenectomy was performed. After a macroscopic examination, the mass lesion was diagnosed as gossypiboma. Although ultrasonography (US), CT, angiography, and magnetic resonance imaging (MRI) may be used to diagnose gossypiboma, definitive diagnosis is possibile only upon surgery or histopathological examination. As a result, when an abdominal mass is observed, surgeons should carefully investigate the patient’s past surgical history while taking the possibility of gossypiboma into consideration.