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Dive into the research topics where Abdurrahman Simsek is active.

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Featured researches published by Abdurrahman Simsek.


World Journal of Surgery | 2005

Results of Surgical, Laparoscopic, and Percutaneous Treatment for Hydatid Disease of the Liver: 10 Years Experience with 355 Patients

Gokhan Yagci; Bahri Ustunsoz; Nihat Kaymakcioglu; Ugur Bozlar; Semih Gorgulu; Abdurrahman Simsek; Ali Akdeniz; Sadettin Cetiner; Turgut Tufan

Selection of the most appropriate treatment to obtain the best results with the lowest rate of recurrence and minimal morbidity and mortality is mandatory for the management of hepatic hydatid disease. The surgical approach is the mainstay of treatment, and there has been a tendency toward laparoscopic surgery and, more recently, percutaneous treatment (PT), which has become increasingly popular with revolutions in techniques. We aimed to evaluate the results of current therapeutic methods in the context of a 10-year single-institution experience. Between 1992 and 2003, 355 patients with 510 hydatid cysts of the liver were treated by open operation, laparoscopic surgery, or PT. The series included 128 females and 227 males ranging in age from 10 years to 73 years. Preferred treatment modalities, perioperative complications, interventions, recurrences, and length of hospital stay were retrospectively analyzed. There were two postoperative deaths (1.08%) in the open surgery group. Biliary leakage was observed in 28 patients treated with open surgery, in 10 patients after PT, and in 2 after laparoscopic treatment. Recurrence rates were 16.2%, 3.3%, and 3.5% after open surgery, laparoscopic surgery, and percutaneous treatment, respectively. Characteristics of the cyst, presence of cystobiliary communications, and the availability of a multidisciplinary team are the factors that we believe directly affect the results. Radical surgery can be done safely for suitable cases; conventional procedures are associated with greater morbidity. Laparoscopic surgery seems effective and safe, with low morbidity and recurrence rates for type I–III cysts in accessible localizations. Our experience with PAIR (puncture, aspiration, injection, and reaspiration) and catheterization provides evidence that the procedure is an effective and safe option.


Techniques in Coloproctology | 2005

Treatment of pilonidal sinus by phenol application and factors affecting the recurrence.

Nihat Kaymakcioglu; Gokhan Yagci; Abdurrahman Simsek; Aytekin Unlu; O. F. Tekin; Sadettin Cetiner; Turgut Tufan

BackgroundPhenol injection, a less invasive method, has become more popular for the treatment of sinus pilonidalis. Recurrence rates after the use of phenol have been reported to be less than those after other surgical methods.MethodsIn this study, we applied 80% phenol to 143 patients with sinus pilonidalis. Patients were reevaluated at 1, 3, 6, 12 and 24 months after the phenolization procedure to search for any recurrences. Age, sex, skin color, occupation, hair distribution, complaints, macroscopic characteristics of the lesion, pouch volume, microbiological yield, complications of phenol injection, healing time, and recurrences were determined.ResultsThe mean follow-up period was 24 months and the recurrence rate was 8.3% (12 of 143 patients). Volume of the sinus tract and number of sinus orifices were determined to be the factors significantly affecting recurrences (p<0.05).ConclusionsInjection of 80% phenol is an ideal approach for the conservative treatment of sinus pilonidalis. This study confirms that this is an effective and costless method with low recurrence rates.


Journal of Gastroenterology | 2004

Beneficial effects of N-acetylcysteine on sodium taurocholate-induced pancreatitis in rats

Gokhan Yagci; Husamettin Gul; Abdurrahman Simsek; Varol Buyukdogan; Onder Onguru; Nazif Zeybek; Ahmet Aydin; Müjdat Balkan; Oguzhan Yildiz; Dervis Sen

BackgroundAcute pancreatitis (AP) is a complex disease associated with significant complications and a high rate of mortality. Although several mechanisms are put forward, oxidative stress seems the most important early event in the pathophysiology of AP. Therefore, we evaluated the beneficial effects of N-acetylcysteine (NAC), a strong antioxidant, in experimental AP.MethodsForty-nine Sprague-Dawley rats were used. Acute pancreatitis (AP) was induced by the intraductal infusion of sodium taurocholate. Rats were divided into seven groups (each containing seven rats): control, sham-operated (saline-treated, 3.5 and 12 h), non-treated AP (3.5 and 12 h) and NAC-treated AP (3.5 and 12 h). Treated rats received intraperitoneal (i.p.) NAC 1000 mg/kg 24 h before and just before the induction of pancreatitis.ResultsRats with AP had extensive parenchymal and fat necrosis and NAC treatment at 12 h reduced tissue necrosis significantly (P ≪ 0.05). NAC treatment at 12 h reduced leukocytic infiltration significantly (P ≪ 0.05). Edema and hemorrhage were significantly increased in the AP groups when compared to controls (P ≪ 0.001). NAC treatment reduced edema and hemorrhage at both 3.5 and 12 h slightly but not significantly. The total pathological mean score was significantly increased in the AP groups (P ≪ 0.05) and it was reduced by NAC treatment (P ≪ 0.05). NAC treatment decreased plasma amylase and lipase levels significantly (P ≪ 0.05). While glutathione peroxidase (GPx) activity of pancreatic tissue was similar in the NAC-treated and AP groups, hepatic tissue GPx activity was lower in the AP groups, and NAC treatment restored it (P ≪ 0.05). NAC had no effect on pancreatic superoxide dismutase level. In the NAC-treated rats, the serum NO2/NO3 (nitrite/nitrate) level was significantly increased in the 3.5-h group when compared to the respective AP group (P ≪ 0.05). NAC treatment also significantly reduced the serum concentration of the lipid peroxidation product, malondialdehyde, at 12 h (P ≪ 0.05).ConclusionsNAC treatment had beneficial effects in sodium taurocholate-induced AP in rats. It reduced pancreatic tissue necrosis and lipid peroxidation. In our study, the mechanism underlying the beneficial effects of NAC seemed to be its antioxidant activity, either by increasing hepatic GPx activity, or by a direct scavenging effect on free radicals, thus enhancing the production of and/or inhibiting the degradation of nitric oxide.


Journal of Surgical Research | 2003

The effects of gingko biloba extract (EGb 761) on experimental acute pancreatitis

Nazif Zeybek; Semih Gorgulu; Gokhan Yagci; Muhittin Serdar; Abdurrahman Simsek; Nihat Kaymakcioglu; Salih Deveci; Hakan Ozcelik; Turgut Tufan

BACKGROUND AND OBJECTIVE Acute pancreatitis is an important and fatal disease with high mortality and morbidity. Although the pathogenesis of acute pancreatitis is poorly understood, there are many studies that suggest the role for oxygen free radicals (OFRs) in the development of pancreatitis and its complications and show beneficial effects of scavenger treatment. In the present study, we aimed to investigate whether Egb761, the standardized extract of gingko biloba, restrains the generation of OFRs and ameliorates the histopathologic findings of acute pancreatitis. MATERIALS AND METHODS Sixty male Sprague Dawley rats were randomly assigned to one of the following experimental groups. In early and late pancreatitis and treatment groups, acute pancreatitis was induced by retrograde infusion of 3% sodium taurocholate. In treatment groups, 100 mg/kg Egb 761 was given intraperitoneally (IP) 24 h and immediately before induction of pancreatitis. Sham-operated rats received isotonic saline instead of sodium taurocholate. After observation times of 3.5 and 12 h, the pancreas was removed for light microscopy and determination of malondialdehyde (MDA) levels as a marker for OFRs-induced lipid peroxidation. Serum samples also were obtained for amylase and lipase levels. RESULTS There was no significant difference in control and sham-operated groups in terms of histopathologic findings and serum enzyme levels. The tissue concentrations of MDA and serum enzyme levels were significantly elevated in early and late treatment groups as compared with the control group. The treatment with Egb 761 caused significant decrease in serum amylase and lipase levels and histopathologic scores as compared with early and late pancreatitis groups. CONCLUSIONS Prophylactic application of Egb761 exerts highly beneficial influence on the course of acute pancreatitis, and this seems to be related to the oxygen radical scavenger effect of Egb761.


Journal of Cardiovascular Pharmacology | 2003

Pharmacologic characterization of contractile serotonergic receptors in human isolated mesenteric artery.

Husamettin Gul; Oguzhan Yildiz; Abdurrahman Simsek; Müjdat Balkan; Nail Ersoz; Sadettin Cetiner; Askin Isimer; Dervis Sen

The 5-hydroxytryptamine (5-HT) receptors mediating contraction in human isolated mesenteric arteries were characterized. Endothelium-denuded human isolated mesenteric arteries were used. 5-HT induced concentration-dependent contractions in mesenteric arteries (Emax, 127.37 ± 7.61% of 80 m M KCl maximal contraction; pD2, 6.73 ± 0.09 [−logEC50]). Sumatriptan, a selective 5-HT1B/1D receptor agonist, induced concentration-dependent contractions in some of the arteries (Emax, 61.82 ± 10.04%; pD2, 6.56 ± 0.21, n = 9) but not in the others (Emax < 5%, n = 13), suggesting that functional 5-HT1B/1D receptors exist in some but not in all mesenteric arteries. GR127935 (a selective 5-HT1B/1D receptor antagonist, 3 n M) inhibited sumatriptan-induced contractions in arteries in which sumatriptan responses were strong in an insurmountable manner. GR127935 (10 n M) also inhibited 5-HT responses and shifted the concentration–response curve of 5-HT to the right significantly (p < 0.05; pD2s were 6.54 ± 0.18 and 5.93 ± 0.11 in the presence of vehicle and GR127935, respectively). Ketanserin (0.01–1 &mgr;M) competitively antagonized 5-HT responses in human mesenteric arteries: pA2 value was 8.40 ± 0.25 (slope of Schild regression, 1.43 ± 0.18; r2, 0.98). Tropisetron (5-HT3 receptor antagonist) and prazosin (&agr;1-adrenoceptor antagonist) did not affect the contractions induced by 5-HT. These results suggest that 5-HT2A and 5-HT1B/1D receptors, but not 5-HT3 and &agr;1-adrenoceptors, are involved in the 5-HT–induced contractions in human isolated mesenteric arteries. Sumatriptan-induced and 5-HT1B/1D receptor-mediated responses vary greatly among patients.


Nutrition | 2009

Preoperative administration of oral carbohydrate-rich solutions: Comparison of glucometabolic responses and tolerability between patients with and without insulin resistance

Mehmet Fatih Can; Gokhan Yagci; Birgul Dag; Erkan Ozturk; Semih Gorgulu; Abdurrahman Simsek; Turgut Tufan

OBJECTIVE Preoperative carbohydrate loading with clear fluids is thought to reduce surgery-related insulin resistance (IR). However, IR per se is already present in some patients scheduled for elective surgery. Data on the safety of preoperative oral carbohydrate loading in patients with IR undergoing surgery is lacking. We aimed to evaluate the effects of preoperative carbohydrate loading on the glucometabolic state and gastric content of patients with and without IR. METHODS Thirty-four non-diabetics received 800 mL of a special carbohydrate-containing drink on the evening before the operation and then 400 mL 2 h before surgery. Blood samples for glucose, insulin, and cortisol levels were taken immediately before the second dose, at 40 and 90 min after intake of the drink, and at the onset of surgery. Patients with a homeostasis model assessment IR score >2.5 were considered to have IR. The differences between patients with and without IR were then evaluated. RESULTS Eight of the 34 patients had IR and the remaining 26 did not. Glucose levels in the IR group were higher than those in the non-IR group, but the differences did not reach significance. The initially elevated insulin concentrations then tended to decrease to the corresponding levels detected in the non-IR group. The cortisol concentrations were similar in both groups. CONCLUSION Patients with IR receiving a carbohydrate-rich drink before surgery appear not to be affected adversely by the beverage. Furthermore, they also obtain the probable beneficial effects related to these drinks and, like patients without IR, can undergo surgery safely.


Acta Chirurgica Belgica | 2004

Diagnostic features and treatment modalities in solitary rectal ulcer syndrome.

Abdurrahman Simsek; Gokhan Yagci; Semih Gorgulu; Nazif Zeybek; Nihat Kaymakcioglu; Dervis Sen

Abstract Solitary rectal ulcer syndrome (SRUS) is a traumatic lesion of the anterior or circular rectal wall caused by straining due to functional disorders of defecation. Defecography, transrectal ultrasonography or anorectal manometry are suitable procedures that may be used to detect the causative disorder and should, therefore, be performed in patients with solitary rectal ulcer syndrome. Histopathological features of SRUS are characteristic and pathognomonic, nevertheless the endoscopic and clinical presentations may be confusing. The lesions may mimic other rectal pathologies and lead to wrong diagnosis. We retrospectively evaluated 34 patients with SRUS who had various treatments. Rectosigmoidoscopy, defecography, transrectal ultrasonography and anorectal manornetry were performed for evaluat ion of cases. The operative management was rectopexy in 26 patients, rectal mucosectomy in 4 patients, segmental colonic resection in 2 patients, local excision in 1 patient and colostomy in 1 patient. Total regression and healing of the ulcer occurred in 32 of 34 patients. Partial regression of symptoms in 2 patients, who underwent rectopexy and rectal mucosectomy, occurred, but we could not get complete healing.


Anz Journal of Surgery | 2005

Enteric and rectal duplications and duplication cysts in the adult.

Abdurrahman Simsek; Nazif Zeybek; Gokhan Yagci; Nihat Kaymakcioglu; Hüseyin Taş; Mutlu Saglam; Sadettin Cetiner

Alimentary tract duplication and duplication cysts are rare congenital malformations. The ileum is the most frequently affected site. However, alimentary tract duplication and duplication cysts can occur at any point along the gastrointestinal tract. Early diagnosis and prompt surgical treatment is the best way to prevent associated morbidity. This article presents the cases of three patients admitted to Gulhane Military Medical Academy with signs of acute abdomen, intra‐abdominal mass and chronic abdominal pain. These patients were found to have enteric duplication, duplication cyst and/or retro‐rectal cyst. The literature on alimentary tract duplications is reviewed.


The Eurasian Journal of Medicine | 2013

The Role of 2-[F-18] Fluoro 2-Deoxy D-Glucose Positron Emission Tomography in the Preoperative Staging of Gastric Cancer

Kazim Duman; Abdurrahman Simsek; Semih Gorgulu; Gokhan Yagci; Yusuf Peker

OBJECTIVE FDG-PET can contribute significantly to the preoperative period of patients with planned curative resections or with isolated liver or lung metastasis. In this study, we analyze the importance and diagnostic value of FDG-PET in the preoperative evaluation of gastric cancers by correlating its value with computerized tomography (CT). MATERIALS AND METHODS A prospective study was conducted. Abdominal and pelvic CTs were obtained for preoperative staging in each patient. Separate stagings were performed according to the findings of conventional methods and PET scans, and the results were compared with the operative and histological findings. RESULTS When the patients were evaluated according to the pathological stage, eight patients were Stage 1 (26.7%), five were Stage 2 (16.7%), eight were Stage 3 (26.7%), and nine were Stage 4 (30%). FDG-PET and CT down-staged the disease in eight (26.7%) and twelve (40%) patients, respectively. FDG-PET and CT up-staged the disease in two (6.7%) and five patients (16.7%), respectively. FDG-PET accurately staged the disease in eighteen patients (60%) (p= 0.182). CONCLUSION To develop highly sensitive radioactive tests that show invasive local lymph node and peritoneal metastases, more studies in the preoperative staging of gastric cancer are needed. FDG-PET indicates a high specificity in the staging of gastric cancer. In patients who are planned for curative surgery, FDG-PET provides better staging when used with CT.


Saudi Medical Journal | 2006

Surgical treatment of anorectal injuries

Nihat Kaymakcioglu; Tahir Özer; Gokhan Yagci; Abdurrahman Simsek; Öner Menteş; Ali Harlak; Nazif Zeybek; Turgut Tufan

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Gokhan Yagci

Military Medical Academy

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Nazif Zeybek

Military Medical Academy

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Semih Gorgulu

Military Medical Academy

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Turgut Tufan

Military Medical Academy

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Dervis Sen

Military Medical Academy

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Tahir Özer

Military Medical Academy

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Yusuf Peker

Military Medical Academy

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Birgul Dag

Military Medical Academy

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