Mehmet Bektas

• MD
• Professor at Ankara University, Faculty of Medicine, Ankara, Turkey

Objectives : Autoimmune gastritis (AIG) is an antibody-mediated autoimmune disease and characterized by gastric parietal cell loss. Type-1 gastric carcinoid tumor (GCT) is a disease that mostly develops on the basis of AIG. The aim of this study is to determine similarities and differences of baseline clinical parameters between these two disorders...

The gastrointestinal (GI) system is one of the most commonly affected sites during a hematopoietic stem cell transplantation (HSCT) due to toxicities of preparative regimens, the accompanying immunodeficiency, and organ damage caused by graft versus host disease. In this review, we focus on early GI and liver complications following autologous (aut...

An 11-year-old morbidly obese boy was diagnosed with pancreatic pseudocyst. Following fine needle aspiration, the cyst recurred in 1-month follow-up. Therefore, endoscopic drainage and cystoduodenostomy was performed following endosonography. Control ultrasonography (USG) revealed a completely shrunken cyst. During the 3 years of follow-up, the pat...

Background The aim of this study was to investigate whether any esophageal motor dysfunction exists in patients with iron deficiency anemia (IDA). Methods The study included 39 patients (34 women, mean age: 44.17 ± 14.21 years) who met WHO diagnostic criteria for IDA. An additional 30 functional dyspepsia patients were also included as a control g...

Background The aim of this study was to investigate relationships between early atherosclerosis and inflammatory bowel disease (IBD) using laboratory, functional, and morphological markers of atherosclerosis. Material/Methods In the present prospective single-center study, 96 patients with IBD (58 patients with ulcerative colitis and 36 patients w...

Gastric wall abscesses are rare infectious pathologies. We present a 11-year-old boy who had complaints of abdominal pain and vomiting and was diagnosed as gastric wall abscess. He presented with complaints of abdominal pain and vomiting that had started two days ago. He also had a history of Myasthenia Gravis. Computerized tomography scans reveale...

This pictorial review aims to illustrate the magnetic resonance imaging (MRI) findings and presentation patterns of anatomical variations and various benign and malignant pathologies of the duodenum, including sphincter contraction, major papilla variation, prominent papilla, diverticulum, annular pancreas, duplication cysts, choledochocele, duoden...

Background and objectives: Extra-pancreatic cysts (EPCs) are incidentally found in patients with pancreatic cystic lesions (PCLs). The aim of this study is to find the prevalence of concurrent EPC in patients with PCLs, investigate associations with neoplastic lesions, and compare the prevalence of EPC to a control population. Materials and metho...

Background and Aims:Intestinal Behcet’s disease may cause serious complications, including massive hemorrhage, fistulisation and intestinal perforation, which are encountered in approximately 50% of patients. Currently, there is little data on iatrogenic ileocolonic perforation during colonoscopy in patients with intestinal Behcet’s disease; theref...

Öz • tr • en Endoskopik hemostaz metotları Mallory-Weiss Sendromuna ba¤lı üst gastrointestinal kanamalarda güvenli ve etkin bir yaklaşım olarak kabul edilmektedir. Kronik öksürü¤ü olan 62 yaşındaki bir erkek hasta ve 27 yaşında 10 haftalık gebe hasta klini¤imize ciddi hematemez bulgularıyla başvurdu. Bu hastalara üst gastrointestinal endoskopi uy...

Öz • en • tr Although the exact prevalence of cystic pancreatic lesions is unknown, it is estimated to be around 1% of the general population based on large-scale observational imaging studies. Cystic pancreatic lesions are increasingly diagnosed due to the widespread use of cross-sectional imaging modalities like computed tomography and magnetic...

Endoscopic ultrasonography has gained a pivotal role in cancer staging for gastrointestinal malignancies because of its ability to image both the layers of the intestinal wall and peri-intestinal lymph nodes and organs. Endoscopic ultrasonography should be used after computerized tomography, positron emission tomography scanning or magnetic resonan...

Öz • tr • en Alt gastrointestinal kanama şüphesiyle kolonoskopi yapılan 61 yaşında kadın hastada sigmoid kolonda uzun saplı bir polip saptandı. Polipektomi yapılan hastada işlem sonrası ciddi arteriyel kanama olması üzerine işlem bölgesine acilen epinefrin ve sklerozan ajan uygulanarak kanama kontrolü sa¤landı. 3 saat sonra hastanın rektal kanama...

Introduction/aim Primary biliary cirrhosis is associated with other autoimmune diseases including Sjögren's syndrome, and scleroderma. Esophageal dysmotility is well known in scleroderma, and Sjögren's syndrome. The aim of this study is to investigate whether any esophageal motor dysfunction exists in patients with primary biliary cirrhosis. Metho...

In this paper, we report the case of a 19-year-old male patient who presented with lymphoblastic phase of chronic myeloid leukemia and received an allogeneic bone marrow transplant from his cousin. The patient experienced severe, steroid-refractory acute graftversus-host disease of skin, gastrointestinal tract and liver that required further immuno...

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an excellent method for primary lung cancer staging. We describe a 66-year-old male who underwent EUS-FNA for the diagnosis of recurrent lung cancer. Two years after initial radiation therapy followed by complete remission, routine follow-up imaging study revealed a mass in the right...

Background/aims: EUS guided Natural Orifice Transluminal Endoscopic Surgery (NOTES) could be a potentially viable approach for pancreatic surgery. EUS-guided access through the stomach wall may prove to be a safe and effective method for accessing the pancreas. The aim of the study was to assess the EUS-guided diagnostic and therapeutic procedures...

Autoimmune gastritis (AIG) may predispose to gastric carcinoid tumors or adenocarcinomas and may also cause unexplained iron and/or vitamin B(12) deficiency. The aims of this study were to explore clinical manifestations, endoscopic findings and laboratory features of patients with AIG. 109 patients with AIG were enrolled into the study. In additio...

Excessive release of gastrin leads to hypertrophy and hyperplasia of enterochromaffin-like cells (ECL) and prolonged stimulation of these cells causes functional impairment. The purpose of this study was to investigate the effect of Helicobacter pylori (H. pylori) infection and long-term proton pump inhibitors (PPI) use on ECL cells. Fifteen patien...

The effect of exogenous hypergastrinemia on esophageal motor function has been well documented. However, it is not known whether chronic endogenous hypergastrinemia influences esophageal motility and lower esophageal sphincter pressure. The purpose of this study was to investigate the effect of chronic hypergastrinemia on lower esophageal sphincter...

Pancreatic neuroendocrine tumors (PNET) are fairly uncommon. Recent data highlight the importance of EUS in diagnosis of PNET. With this background, we decided to review our experience from a tertiary cancer center with regard to the presentation and clinical features of PNET and the diagnostic utility of EUS-FNA in this scenario. We identified pat...

The aims of this cohort study were to evaluate the association of malignant lymphoproliferative disorders in patients with chronic viral hepatitis and to compare the results with those in individuals with non-alcoholic fatty liver disease. A total of 3,873 patients with chronic liver disease who were seen consecutively in the Liver Disease Outpatie...

Celiac disease shares several symptoms which constitute some of the ROME criteria used for the diagnosis of irritable bowel syndrome (IBS), and as such many patients with underlying Celiac disease may be mistakenly diagnosed as having IBS. The aim of the present study was to determine the prevalence of Celiac disease in patients with IBS fulfilling...

We aimed to report the outcomes of different H. pylori eradication regimens used in our institution over the last 10 years. Retrospectively, H. pylori-positive patients who were referred for upper gastrointestinal endoscopy with dyspeptic symptoms and who started eradication treatment and returned for a follow-up visit were included in the study. S...

The esophageal mural veins are important for providing blood to the esophageal submucosal varices. The purpose of this study was to investigate any correlation between the diameters of esophageal mural veins as observed on routine contrast-enhanced magnetic resonance angiography and the endoscopic grades of esophageal varices in patients with porta...

The aim of this cohort study was to determine the characteristics and clinical outcome of 170 patients with drug-induced liver injury (DILI) in a single center. Between January 2001 and June 2007, a total of 170 individuals who were diagnosed with DILI were retrospectively analyzed. The median follow-up period was 110.0 days. During the study perio...

Heterotopic gastric mucosa occurs as a flat island of red mucosa in the proximal third of the esophagus where it gives rise to the cervical inlet patch. The aims of this study were to investigate the esophageal motility pattern and 24-h pH profiles of patients with cervical inlet patch. Thirty patients (16 women, mean age: 44.9 years, range: 23-72)...

Invasive and non-invasive tests can be used to evaluate the activity of inflammatory bowel diseases. The aim of the present study was to investigate the role of fecal calprotectin in evaluating inflammatory bowel disease activity and the correlation of fecal calprotectin with the erythrocyte sedimentation rate and C reactive protein values in infla...

The aims of this study were to evaluate esophageal motor function in patients with Familial Mediterranean Fever (FMF) who had upper gastrointestinal symptoms and to compare esophageal motor function between FMF patients who developed amyloidosis and patients without amyloidosis. 31 FMF patients with dyspeptic symptoms and 31 healthy age-matched ind...

Hepatocellular carcinoma is the fifth most common cancer and a major public health problem worldwide. Differences in distribution of hepatocellular carcinoma incidence are probably due to different levels of exposure to hepatocellular carcinoma risk factors: chronic infections with hepatitis B virus (HBV) and aflatoxin exposure in developing countr...

The aims of this study were to investigate the effect of Helicobacter pylori eradication on gastroesophageal reflux, gastrointestinal symptoms and quality of life in patients with functional dyspepsia. 20 H. pylori positive patients diagnosed as having functional dyspepsia according to Roma-II criteria completed the study period. Esophageal motilit...

The American Journal of Gastroenterology is published by Nature Publishing Group (NPG) on behalf of the American College of Gastroenterology (ACG). Ranked the #1 clinical journal covering gastroenterology and hepatology*, The American Journal of Gastroenterology (AJG) provides practical and professional support for clinicians dealing with the gastr...

Unlabelled: AIM/MATERIALS AND METHODS: Between January 2000 and June 2007, 3,548 endoscopic retrograde cholangiopancreatography (ERCP) were performed for extrahepatic cholestasis, cholangitis, and choledocholithiasis. The results of ERCPs were evaluated retrospectively and examined carefully to investigate the management and endoscopic therapy of...

The aims of the study were to investigate the efficacy of rescue therapy with lamivudine (LAM) and adefovir (ADV) combination for 6 months followed by ADV monotherapy in lamivudine-resistant chronic hepatitis B (LAM-R CHB) patients, and to analyze the frequency of ADV resistance mutant development in such patients. A total of 170 consecutive LAM-R...

Several lines of evidence suggest that peroxisome proliferator-activated receptor alpha may be involved in hepatocarcinogenesis. L162V polymorphism of the peroxisome proliferator-activated receptor alpha gene enhances the transactivation activity of this transcription factor. The aim of this study was to determine the frequency and clinical correla...

The esophagus is the most common site of origin of gastrointestinal tract granular cell tumors. Approximately 270 cases of esophageal granular cell tumors have been reported in the literature. Most esophageal granular cell tumors are found incidentally during endoscopy. Although granular cell tumor of the esophagus has become easily recognizable by...

Tangier disease is a rare, autosomally inherited disorder of lipoprotein metabolism characterized by absence or marked deficiency of normal high density lipoprotein (HDL) cholesterol in plasma resulting in the accumulation of cholesterol esters in various organs. A 57-year old male with a past medical history of hypertension, coronary artery diseas...

Currently, although only a few therapies normalize the liver test abnormalities with/without improving the liver histology, no pharmacologic therapy has proved to be effective for the treatment of non-alcoholic steatohepatitis. To investigate the role of insulin sensitizers in the treatment of individuals with non-alcoholic steatohepatitis (NASH)....

Therapeutic plasma exchange (TPE) seems to be an effective approach for clearing toxins, immune-mediated antigens, and other particles from the circulation. The aim of this study was to analyze the positive effects of TPE on clinical and biochemical parameters of liver failure. Between January 2001 and March 31, 2005 individuals (men/women, 17/14;...

Familial Mediterranean fever is an autosomal recessive disorder characterized by sporadic, paroxysmal attacks of fever and serosal inflammation. In Familial Mediterranean fever, peritoneal effusion during abdominal attacks is usually mild, is not detected by clinical evaluation, and disappears during clinical remission. Chronic ascites has rarely b...

A case of Kaposi's sarcoma (KS) in a 70-year-old man who was using corticosteroid for the treatment of asthma is presented. KS lesions occurred in the skin, colon, and rectum. Macroscopic appearances of the lesions varied from polypoid, hemorrhagic mucosal nodules and ulcers to red macules in the mucosal plane to plaque-like indurations of the wall...

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Alterations in expression of mucins and aberrant expression of various types of mucin genes were observed in colorectal adenomas and carcinomas, though their significance in neoplastic transformation of colorectal epithelium is yet to be determined. The aim of this study was to determine expression of MUC1, MUC2, MUC5AC, and MUC6 through convention...

The purpose of the current study was to investigate the role of beta-catenin, E-cadherin and P-cadherin in colorectal carcinogenesis using tissue array method. Core tissue biopsies were taken from paraffin-embedded tissue blocks of 167 cases including 26 normal mucosae (NM), 99 colorectal polyps (10 hyperplastic polyps (HP), 8 traditional serrated...

Gastrointestinal (GI) involvement in Behçet's disease (BD) mainly appears in mucosa and affects 5-40% of patients, however the effects of the disease on lower esophageal sphincter (LES) pressure and esophageal contractions are not well known. The aims of this study were to evaluate esophageal motor function and to identify whether there was any spe...

Sorry, there is no abstract.

A 47-year-old woman presented with a 2-month history of generalized arthralgia and a 10-day history of oral aphthous ulcers. After hospitalization, papulopustular lesions and perianal ulcerations developed. Pathergy test was positive and ophthalmological examination was normal. The presence of oral aphthous ulcers, genital ulcerations, papulopustul...

Nonalcoholic fatty liver disease (NAFLD) comprises a wide spectrum of liver injury, ranging from steatosis and steatohepatitis to cirrhosis. Reasons for the different natural course in individuals with NAFLD are still unclear. The aim of this study was to describe the natural course of disease in individuals with NAFLD who did not receive pharmacol...

Three missense mutations clustered on the carboxyl-terminal portion of the MEFV gene (M680I, M694V, and V726A) have been observed in over 80% of affected alleles in several ethnic groups of familial Mediterranean fever patients. Several immunologic abnormalities were found both in cellular and humoral components in Mediterranean fever patients. Tho...

Proton pump inhibitors have been widely used in recent years. However, there are studies suggesting that proton pump inhibitors may not control the gastric acidity effectively during the night, especially in gastroesophageal reflux disease. It has therefore been suggested that H2 receptor blockers should be added to the therapy. The aim of our stud...

In this study we screened 3060 consecutive blood donors for an unbound iron-binding capacity level of <28 microM and then performed HFE mutation analysis in these subjects. Sixty-five of the 75 subjects with a low initial unbound iron-binding capacity (all had normal ferritin levels) came back and only 5 (8%) had a low fasting unbound iron-binding...