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Dive into the research topics where Levent Erdem is active.

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Featured researches published by Levent Erdem.


Journal of Gastroenterology and Hepatology | 2004

Heterotopic gastric mucosa in the cervical esophagus (inlet patch): Endoscopic prevalence, histological and clinical characteristics

Nihat Akbayir; Canan Alkim; Levent Erdem; H. Mehmet Sökmen; Ayşim Sungun; Tulay Basak; Suat Turgut; Zeynel Mungan

Background and Aim:  Heterotopic gastric mucosal patch, which has a 0.1–10% frequency, is encountered when the cervical esophagus is examined carefully during endoscopy. In this study, we aimed to determine the prevalence of the patch in the cervical esophagus, to identify its macroscopic and histological characteristics and to evaluate demographic and clinical features.


Digestive Diseases and Sciences | 2005

Sensorineural Hearing Loss in Patients with Inflammatory Bowel Disease: A Subclinical Extraintestinal Manifestation

Nihat Akbayir; Asli Batur ÇAliŞ; Canan Alkim; H. Mehmet Sökmen; Levent Erdem; AyÇA Özbal; F. Füsun Bölükbaş

Isolated case reports in which symptomatic hearing loss develops suddenly during the course of inflammatory bowel disease (IBD) have been reported, but the presence of subclinical sensorineural hearing loss (SNHL) associated with IBD has been investigated in only two preliminary studies.In order to research this further, we aimed to investigate the presence of subclinical SNHL in IBD by comparison with a control group and to examine possible relations between the bowel disease parameters and hearing loss.Otoscopy, tympanometry, and pure tone audiometry were carried out in 39 patients with IBD (21 Crohns disease [CD], 18 ulcerative colitis [UC]) and 25 healthy age- and sex-matched controls. All patients and control subjects had normal otoscopy findings and tympanometry was unremarkable, excluding middle ear disease and conductive hearing loss. Analysis of each frequency examined showed that the average hearing thresholds were increased significantly in the study group compared to those of the control group at higher frequencies (2, 4, and 8 kHz). When these parameters were compared with the control group according to subgroups of IBD, a significant difference was determined for the UC group at frequencies of 2, 4, and 8 kHz and for the CD group only at the frequency of 4 kHz. Although there was a trend of increment in SNHL as the age of the patient and duration and extent of UC increased, no significant correlation was observed between SNHL and these parameters or sex, activity, involvement site, medication history of IBD, and coexistence of other extraintestinal manifestations. In conclusion, it was demonstrated that a subclinical SNHL may be associated with UC and somewhat with CD, affecting mainly the high frequencies. In light of this finding, it may be advisable to investigate labyrinth functions as well as other extraintestinal manifestations in patients with IBD.


European Archives of Oto-rhino-laryngology | 2005

Investigation of Helicobacter pylori colonization in laryngeal neoplasia

Nihat Akbayir; Tulay Basak; Huseyin Seven; Ayşim Sungun; Levent Erdem

Helicobacter pylori has been investigated in several other organ systems and localizations such as the oral cavity, but has not been investigated extensively in squamous cell carcinoma of the larynx, a region that could be directly exposed to the bacterium by the oral route or gastro-esophageal reflux. Only serological studies are available regarding the relation between H. pylori and laryngeal cancer, yielding conflicting results. To our knowledge, there is no study investigating the presence of H. pylori in laryngeal squamous cell carcinoma tissue. The purpose of this study was to investigate the presence of H. pylori in laryngeal squamous cell carcinoma tissue and to investigate the possible role of this organism in the etiopathogenesis of laryngeal cancer. Specimens from 50 patients with laryngeal cancer who underwent total or partial laryngectomy between March 1999 and December 2002 were examined by histopathological and immunohistochemical methods to detect H. pylori. The presence of H. pylori was also investigated histopathologically in 50 benign laryngeal biopsy specimens. In our study, we demonstrated that H. pylori was not present in laryngeal squamous cell carcinoma tissue or in the benign lesions. We could not find any evidence indicating that H. pylori played a role at the tissue level in the pathogenesis of laryngeal carcinoma.


Journal of Gastrointestinal Surgery | 2004

Colonic interposition vs. gastric pull-up after total esophagectomy

Sadik Yildirim; Hakan Mustafa Köksal; Fevzi Celayir; Levent Erdem; Muharrem Öner; Adil Baykan

Gastric pull-up is the most frequent reconstruction after esophagectomy. In this report we aimed to compare gastric pull-up with colonic interposition in terms of graft function and patient satisfaction. Of 62 patients undergoing esophagectomy, reconstruction was performed by colonic interposition in 11 and gastric pull-up in 51 (without pyloric drainage in 44 and with pyloric drainage in 7). All esophagectomies were performed transhiatally. Patient follow-up ranged from 6 to 132 months (median 14 months). Follow-up examinations were performed 1, 9, 15, and 24 months postoperatively. The following factors were evaluated: time to the start of oral liquid and solid nutrients without vomiting, frequency of regurgitation, presence of pillow staining (night regurgitation), postprandial fullness, and degree of satisfaction during and after eating compared between groups undergoing colonic interposition and gastric pull-up with or without pyloric drainage. Among patients undergoing gastric pull-up, regurgitation was observed in 22% to 27% during follow-up. None of the patients with colonic interposition had reflux or regurgitation. Twenty-five percent of patients with gastric pull-up without drainage and 66% of patients with gastric pull-up plus drainage had reflux esophagitis at 15 months. No esophagitis was observed in patients with colonic interposition during the same period. Overall satisfaction was superior in patients undergoing colonic interposition followed by gastric pull-up with no drainage. Colonic interposition after esophageal resection is a viable option. Our study suggests that function of the replacement is better in this group of patients.


Journal of Gastroenterology and Hepatology | 2002

Therapeutic vaccination in chronic hepatitis B.

Hakan Senturk; Fehmi Tabak; Meral Akdogan; Levent Erdem; Ali Mert; Resat Ozaras; Ersan Sander; Gulsen Ozbay; Selim Badur

Aims: The aim was to test the efficacy of a pre‐S2‐containing vaccine (Genhevac‐B) in chronic hepatitis B (CHB). Twenty‐five naive patients (22 male, three female; median age 35; range: 6–69 years) with CHB were recruited. The inclusion criteria were: hepatitis B e antigen (HBeAg) positive or HBV‐DNA detectable with liquid hybridization; alanine aminotransferase (ALT) is at least 1.5‐fold the upper normal limit and histological evidence of chronic hepatitis.


Scandinavian Journal of Gastroenterology | 2005

Heterotopic gastric mucosa in the cervical esophagus: could this play a role in the pathogenesis of laryngopharyngeal reflux in a subgroup of patients with posterior laryngitis?

Nihat Akbayir; H. Mehmet Sökmen; Asli Batur Çaliş; Cengiz Bolukbas; Levent Erdem; Canan Alkim; Damlanur Sakiz; Zeynel Mungan

Objective. Acid secretion produced by a heterotopic gastric mucosal patch (HGMP) in the proximal esophagus, instead of gastric acid, may be responsible for laryngopharyngeal reflux (LPR), passing the upper esophageal sphincter. The aim of this study was to investigate the prevalence of HGMP in the proximal esophagus in patients with posterior laryngitis indicating the presence of LPR in comparison with a control group and to elucidate the possible role of this lesion in the pathogenesis of LPR. Material and methods. A total of 36 consecutive patients with posterior laryngitis diagnosed on laryngoscopic examination were enrolled in the study. Esophagoscopy and ambulatory 24-h intra-esophageal dual-probe pH monitoring were performed in all patients. During endoscopy, special attention was paid to the proximal part of the esophagus, and the proximal electrode for pH monitoring was placed in this region under endoscopic view. The control group comprised 660 consecutive patients who had undergone upper gastrointestinal endoscopy for the usual indications. When HGMP was found, biopsies were taken for histological confirmation. Results. HGMP was detected in 5 out of 36 patients. One out of five patients with patches was excluded from the study because the histopathology of this patients patch revealed antral-type mucosa, which is not capable of acid secretion. Thus a total of 35 patients were included in the study, yielding a HGMP prevalence of 11.4% (4/35). Compared with the prevalence of the control group (1.6%), a significant difference was observed (p<0.005). pH monitoring showed that 45.4% of the patients had abnormal proximal acid reflux. All of four HGMP (+) patients with posterior laryngitis revealed significantly higher abnormal proximal reflux compared to the patients without patches (p<0.05). Conclusions. This first preliminary study may suggest that HGMP in the cervical esophagus could play a role in the pathogenesis of LPR, at least in a minor group of patients with posterior laryngitis, depending on its capability to produce acid in situ, although isolated proximal reflux could not be demonstrated. This finding may need to be supported by further studies with larger patient populations and using acid stimulation tests.


Digestive Diseases and Sciences | 2008

Association of Gluten Enteropathy and Irritable Bowel Syndrome in Adult Turkish Population

Kamil Ozdil; Mehmet Sokmen; Ozdal Ersoy; Huseyin Demirsoy; Besir Kesici; Cetin Karaca; Nihat Akbayir; Levent Erdem; Canan Alkim; Damlanur Sakiz

Purpose Irritable bowel syndrome is generally diagnosed according to the symptoms of the patient, and gluten enteropathy can also be presented with similar symptoms (diarrhea and/or constipation) of irritable bowel syndrome. Aimed to assess the association and the frequency of gluten enteropathy in a group of Turkish patients diagnosed as irritable bowel syndrome. Results Found anti-gliadin IgA positivity only in four patients among patients with irritable bowel syndrome. However, none of these four patients had anti-endomycium positivity or any histopathological findings specific for gluten enteropathy. All these four patients had normal histology in their small bowel biopsies. Conclusion Irritable bowel syndrome is a common problem in the population, but gluten enteropathy is not associated with the vast majority of subjects with irritable bowel syndrome as expected. The need for screening gluten enteropathy among these patients is still unclear, and screening with serology only without small bowel biopsy may lead to false positive results.


Asian Journal of Surgery | 2002

Allopurinol Plus Pentoxifilline in Hepatic Ischaemia/Reperfusion Injury

Sadik Yildirim; Hasan Tok; Hakan Mustafa Köksal; Levent Erdem; Adil Baykan

OBJECTIVES Ischaemia/reperfusion injury of the liver is the major cause of liver dysfunction and cellular death in transplantation and in liver resection with hepatic pedicle clamping. Many agents are used to prevent this phenomenon, which occurs following interaction of different mediators during both ischaemia and reperfusion. In this study, we aimed to assess the effects of allopurinol, a xanthine oxidase inhibitor, and pentoxifilline, on liver ischaemia/reperfusion injury when used together and to compare these with the effects of using these agents singly. METHODS Thirty-two rats were divided into four groups consisting of eight rats: Group C, control; Group P, pentoxifilline; Group A, allopurinol; and Group PA, pentoxifilline + allopurinol. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels were measured before hepatic pedicle clamping, on the 45th minute of ischaemia and 15 and 45 minutes after reperfusion. Group P rats were injected with 50 mg/kg pentoxifilline, Group A rats 50 mg/kg allopurinol and Group PA rats were injected with both agents 15 minutes before hepatic pedicle clamping. RESULTS Ischaemia/reperfusion injury was produced by hepatic pedicle clamping, as demonstrated by AST, ALT and LDH increase. Injury prevention occurred in Groups P, A and PA. No significantly different (better) prevention was provided by giving allopurinol plus pentoxifilline to the rats. Furthermore, no difference was observed between the allopurinol and pentoxifilline injected groups in terms of preventing ischaemia/reperfusion injury. CONCLUSIONS Pretreatment with allopurinol or pentoxifilline resulted in significantly lower hepatic enzyme elevation than that in controls in the rat liver ischaemia/reperfusion model. Using both agents does not provide better protection than using either agent alone.


Journal of Clinical Gastroenterology | 2004

Is there any relationship between Hepatitis C virus and vitiligo

Nihat Akbayir; Gonca Gökdemir; Tülin Mansur; Mehmet Sokmen; Sevil Gündüz; Canan Alkim; Burcu Barutcuoglu; Levent Erdem

Goals and Background Hepatitis C virus (HCV) is a hepatotropic and lymphotropic virus. This agent can promote development of a panel of autoimmune diseases. The relationship between HCV infection and vitiligo, in which autoimmune mechanisms are believed to play a role is not yet elucidated. In this study we investigated HCV seropositivity in vitiligo patients and compared this with non-vitiligo population. Study A total of 102 consecutive patients with vitiligo were included in the study (47 male, 55 female, mean age: 36.8 ± 16.9 years, range: 5–75). Control population was 670 age and sex matched healthy blood donors (406 male, 264 female, mean age: 32.8 ± 11.3 years, range: 20–58). Third generation enzyme immunoassay was used for serum anti-HCV determination. When positive, qualitative confirmation was performed by HCV-RNA determination using RT-PCR. Results Anti-HCV antibody was detected only in 1 patient and confirmed by RT-PCR test. This patient was a 6-year-old girl with a non-segmental form of vitiligo, which is more frequently associated with autoimmune disorders, hence the incidence of HCV seropositivity found as 0.98%. There was no statistically significant difference between this figure and 0.6% prevalence in healthy blood donors. Conclusion Seroprevalence of HCV in vitiligo patients is not different from that of a control group in Turkey, and HCV infection may not be involved in the pathogenesis of vitiligo despite case reports showing co-existence of these 2 diseases.


European Journal of Gastroenterology & Hepatology | 2014

First-line monotherapies of tenofovir and entecavir have comparable efficacies in hepatitis B treatment

Resat Ozaras; Bilgul Mete; Bahadir Ceylan; Nail Ozgunes; Alper Gunduz; Hayat Kumbasar Karaosmanoglu; Atahan Cagatay; Kadir Gokturk; Levent Erdem; Funda Kocak; Ebubekir Senates; Fehmi Tabak

Background Hepatitis B virus (HBV) infection is a health problem worldwide. Current treatment options for chronic hepatitis B (CHB) are nucleoside or nucleotide analogues and pegylated interferons. Tenofovir and entecavir are much more commonly used as they have better efficacy, tolerability, and high genetic barriers to resistance. Aim The aim of this study was to assess the efficacies of tenofovir and entecavir in previously untreated CHB patients in a treatment cohort. Patients and methods We included CHB patients in a cohort including previously untreated HBeAg-positive and HBeAg-negative patients from 10 centers in Istanbul, Turkey. The patients were compared in terms of baseline characteristics, decrease in alanine transaminase (ALT), decrease in HBV-DNA to undetectable levels, HBeAg loss and anti-HBe development (among baseline HBeAg-positive patients), interventions to therapy because of lack of efficacy, side effects, severe side effects, and side effects that required change in treatment. Results The study included 121 patients who were administered tenofovir and 130 patients who were administered entecavir. The majority of patients were men, with mild to moderate histology in both treatment groups. The mean duration of follow-up was 18 and 20 months for tenofovir and entecavir, respectively. Patients receiving both drugs showed comparable rates of HBeAg loss, rates of undetectable HBV-DNA levels, rates of ALT normalization, ALT decrease, and decrease in HBV-DNA. Both drugs were well tolerated. Conclusion This study shows that although the baseline characteristics did not match, tenofovir and entecavir sustained comparable virological efficacies. More patients discontinued entecavir during follow-up. Both drugs provided effective viral control, with few side effects.

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