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Dive into the research topics where Ahmet Ozbek is active.

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Featured researches published by Ahmet Ozbek.


Journal of Clinical Gastroenterology | 2009

Can Helicobacter pylori invade human gastric mucosa?: an in vivo study using electron microscopy, immunohistochemical methods, and real-time polymerase chain reaction.

Ahmet Ozbek; Elvan Ozbek; Hakan Dursun; Yildiray Kalkan; Tuba Demirci

Background-Goals We used transmission electron microscopy and immunohistochemistry (IHC) to investigate how Helicobacter pylori affects the gastric mucosa of humans. Study Gastric biopsy specimens were obtained from 15 patients with gastric discomfort. The samples were processed using both microscopic examinations and a real-time polymerase chain reaction to detect H. pylori DNA. IHC staining was performed with an avidin-biotin complex immunoperoxidase kit for paraffin-embedded tissue sections. Polyclonal rabbit anti-H. pylori was used as a primary antibody. Results IHC-applied slides with brown-stained spiral bacteria on the luminal surface and in the intercellular spaces of the gastric epithelium; electron-dense spiral H. pylori of approximately 200 to 300 nm in diameter both in the gastric lumen and between the gastric epithelial cells; coccoid or ellipsoid H. pylori attached to the epithelial cells through egg-cup-like pedestals; coccoid H. pylori within the endocytotic vesicles in the apical cytoplasmic part of the epithelial cells, thus suggesting their internalization by phagocytosis; electron-dense spiral H. pylori within the membrane-bounded vacuoles of both the gastric epithelial cells, and the lamina propria; a prominent vacuolization of gastric epithelial cells invaded by H. pylori; and swollen and lytic gastric epithelial cells that suggest a mucosal erosion and may lead to peptic ulcer. All of these microscopic findings were not present in the H. pylori DNA-negative specimens that were used as the control group. Conclusion This is the first histomicrobiologic study to show gastric cells invaded by H. pylori in patients with H. pylori infection confirmed by real-time polymerase chain reaction.


Medicina Oral Patologia Oral Y Cirugia Bucal | 2013

Detection of human cytomegalovirus and Epstein-Barr Virus in symptomatic and asymptomatic apical periodontitis lesions by real-time PCR

Selcuk M. Ozbek; Ahmet Ozbek; Muhammed Selim Yavuz

Objectives: Recent studies have investigated the occurrence of human cytomegalovirus and Epstein-Barr Virus in samples from apical periodontitis lesions and a role in the pathogenesis of this disease has been suggested. Because genotype distribution and seroprevalence of EBV and HCMV differ among populations, it is important to determine the presence of these viruses in endodontic periapical lesions of different populations. The aims of this study were to determine the presence of HCMV and EBV DNAs in samples from Turkish patients with symptomatic and asymptomatic apical periodontitis lesions using real-time polymerase chain reaction method and to evaluate their presence in both symptomatic and asymptomatic apical periodontitis lesions. Study Design: Periapical samples were collected from 12 asymptomatic and 16 symptomatic periapical lesions in conjunction with apicectomy. HCMV and EBV DNAs were identified in the samples by real-time PCR. The chi-squared test with Yates’s correction or the Fisher’s exact test was used to analyse the significance of differences. Results: HCMV DNA was detected in 10 of the 16 (62.5%) symptomatic and in five of the 12 (41.7 %) asymptomatic periapical study lesions. The EBV DNA was identified in seven of the 16 (43.7 %) symptomatic and three of the 12 (25 %) asymptomatic periapical lesions. The difference in occurrence of HCMV and EBV DNA between symptomatic and asymptomatic periapical lesions was not statistically significant. (All comparisons have p > 0.05). Conclusions: Our findings suggest that HCMV and EBV is a frequent inhabitant of both symptomatic and asymptomatic apical periodontitis lesions of endodontic origin in Turkish population. Key words:Human cytomegalovirus, Epstein-Barr Virus, apical periodontitis, Polymerase chain reaction method.


Journal of Infection and Public Health | 2017

Socioeconomic indicators are strong predictors of hepatitis A seroprevalence rates in the Middle East and North Africa

Mehmet Koroglu; Kathryn H. Jacobsen; Tayfur Demiray; Ahmet Ozbek; Unal Erkorkmaz; Mustafa Altindis

The goal of this analysis was to examine the association between age-specific hepatitis A virus (HAV) seroprevalence rates and various socioeconomic indicators within the Middle East and North Africa (MENA) region. We conducted a systematic review of all recently published studies on HAV conducted in the MENA region and identified the highest quality studies for inclusion in our analysis. We calculated the age at midpoint of population immunity (AMPI) for each study and estimated seroprevalence rates at the ages of 5, 10, and 15 years. Next, we identified the correlations between these metrics and several socioeconomic variables. HAV data collected in or after 2000 were available for 14 of the 19 countries in the MENA region. Four of the 14 included countries had intermediate HAV endemicity (Algeria, Saudi Arabia, Turkey, and UAE), five had high endemicity (Iran, Jordan, Lebanon, Morocco, and Tunisia), and five had very high endemicity (Egypt, Iraq, Palestine, Syria, and Yemen). Water and sanitation were not significant predictors of AMPI or seroprevalence, most likely because most countries in this region have high rates of access to these utilities. However, gross domestic product (GDP), gross national income (GNI), and the human development index (HDI) were all highly associated with AMPI and prevalence. The observed correlations suggest that of the MENA countries without recent HAV data, Bahrain, Kuwait, and Qatar most likely have low endemicity, Oman likely has intermediate endemicity, and Libya likely has high endemicity. While it is unlikely that a single correlation model would be suitable for use in all world regions, the approach utilized in this analysis might provide a simple but accurate method for using economic data to impute the endemicity profiles of countries without recent data in regions where at least several neighboring countries have conducted recent serostudies.


Jundishapur Journal of Microbiology | 2016

Intra-Abdominal Abscess and Primary Peritonitis Caused by Streptococcus anginosus

Huseyin Agah Terzi; Tayfur Demiray; Mehmet Koroglu; Guner Cakmak; Ihsan Hakki Ciftci; Ahmet Ozbek; Mustafa Altındiş

Introduction The Streptococcus anginosus group of bacteria are low-virulence bacteria existing as commensals in the oral flora and gastrointestinal tracts of humans. S. anginosus may spread to the blood in individuals with poor oral hygiene in cases of oral infections, such as gingivitis and tooth abscesses, that develop following the loss of mucosal unity. This may lead to infections in the whole body, primarily as brain and liver abscesses. Case Presentation A 32-year-old male patient presented with complaints of nausea, vomiting, and diffuse abdominal pain. Diffuse abdominal tenderness and rebound tenderness were detected particularly in the epigastrium and right upper quadrant. Laboratory assessment revealed a leukocyte count of 20,500/mm3. Free fluid around the liver and heterogeneous areas of abscess formation in the right lateral gallbladder were revealed on abdominal computed tomography. Diffuse adhesions between the bowel and seropurulent free liquid in the abdomen were detected on surgical exploration, and a sample was taken for cultures. The patient was discharged without complications on the sixth postoperative day and his antibiotic course was completed with 4 weeks of oral treatment. We reviewed the literature for similar cases of disseminated pyogenic infections caused by the S. anginosus group. Conclusions It should be kept in mind that the oral flora bacterium S. anginosus may cause transient bacteremia and deep-seated organ abscesses in immunodeficient patients with poor oral hygiene. Such patients with intra-abdominal abscesses should be treated with antibiotics and surgery.


Turkish Journal of Pediatrics | 2016

Hepatitis a virus epidemiology in turkey as universal childhood vaccination begins: seroprevalence and endemicity by region

Tayfur Demiray; Mehmet Koroglu; Kathryn H. Jacobsen; Ahmet Ozbek; Huseyin Agah Terzi; Mustafa Altindis

This paper presents the results of a comprehensive examination of current distribution of Hepatitis A virus (HAV) seroprevalence and endemicity in Turkey and the possible links between HAV endemicity and socioeconomic development. We performed a systematic search in online resources published between January 2000 and August 2015. The 22 provinces were able to be assigned a hepatitis A endemicity level based on this systematic review. The incidence rates for symptomatic hepatitis A infection are higher in the eastern part of Turkey than in the western and central region. These differences in socioeconomic indicators by region suggest the likelihood of lower seroprevalence rates in the western parts of the country and higher rates in the eastern region. Turkeys current policy of recommending hepatitis A immunization for all children without contraindications is an appropriate one and is likely to remain the best option for at least the next decade or two.


Pain Clinic | 2006

Microbiological analysis of root canals associated with periapical abscesses (with pain and swelling) and the antimicrobial susceptibility of isolated bacteria

Selcuk M. Ozbek; M. Sinan Evcil; Ahmet Ozbek; Aziz Sahin Erdoğan; Mustafa Köseoğlu

Abstract Objective: The periapical abscess is a collection of pus in the pulp or around the root of teeth. Many odontogenic infections can be managed without antimicrobial therapy or bacteriologic investigation. However, when an acute bacterial infection has progressed or antimicrobial therapy might be of benefit to patients, antibiotics are prescribed. We aimed to identify microorganisms in root canals with periapical abscess and their antimicrobial susceptibility profile in order to revise antimicrobial treatment protocols when antimicrobials are used empirically. Methods: 30 patients (all of whom had pain and swelling) with odontogenic infections were included in this study. The microbiologic investigation was performed under strict aseptic conditions. A standard routine root canal therapy was instituted, and in each case a single root canal was sampled. In multirooted teeth only the largest canal was sampled to preserve the identity of a single endodontic/microbiologic ecosystem. For microbial samplin...


American Journal of Infection Control | 2018

Nail scissors and fingernails as reservoirs of hepatitis B virus DNA: Role of nail scissors in household transmission of hepatitis B virus

Mehmet Koroglu; Tayfur Demiray; Ahmet Ozbek; Ertugrul Guclu; Oguz Karabay; Mustafa Altindis; Riza Durmaz

Background: No study in the current literature has scientifically clarified the transmission of hepatitis B virus (HBV) via personal hygiene tools. We determined risk of household transmission of HBV via nail scissors. Moreover, we assessed whether nails from HBV‐infected people contained HBV, and evaluated correlations of HBV DNA levels of serum, nail specimens, and nail scissors. Methods: Seventy patients testing positive for the surface antigen of the hepatitis B virus (63 positive for HBV DNA) treated for HBV infection and 27 healthy individuals were included. Real‐time polymerase chain reaction method was used to detect HBV DNA levels in sera, nail, and nail scissors. Results: HBV DNA was detected on 27% of nail scissors and in 50% of nail specimens from 63 serum HBV DNA‐positive patients. Serum HBV DNA level >105 IU/mL was associated with 71.8% probability of nail scissors being HBV DNA‐positive (P < .05). Serum HBV DNA level >107 IU/mL was associated with 71.5% probability of fingernails being HBV DNA‐positive (P > .05). Shared‐use of nail scissors was correlated with surface antigen of the hepatitis B virus positivity and total hepatitis B core antibody/immunoglobulin G positivity. A high HBV DNA level was detected in nail scissors and low level HBV DNA in the nails of persons with high serum HBV DNA levels. Conclusions: Nail scissors, shared‐use of nail scissors, and duration of shared use play important roles in household transmission of HBV. Level of education within society in this regard should be increased via mass media.


Journal of microbiology & experimentation | 2016

Evaluation of the Effect of Storage Temperature on D-dimer Stability, Using Two Different Techniques

Engin Karakeçe; Ihsan Hakki Ciftci; Mehmet Koroglu; Ahmet Ozbek

Our study designed to assess the stability of D-dimer levels and storage conditions, using two different techniques. This is the frst study to investigate the short-term storage stability of D-dimers in clinical citrated plasma samples containing a range of D-dimer concentrations. This study was performed with 60 samples that were collected randomly patients with suspected thromboembolism.Plasma samples were incubated for eight different time intervals (0 (i.e., fresh samples), 4, 24, 48, 72, 120, 168, and 240h) and at three different temperatures (25+2 °C,4+2 °C, and -20+2 °C) to evaluate the effect of storage conditions on D-dimer stability.Plasma D-dimer concentrations were determined using two different techniques, a fluorescence-based sandwich immunodetection assay (i-CHROMA, Boditech Med Inc., Korea) and an enzyme-linked immunosorbent assay (ELISA) (VIDAS, bioMerieux, France). In accordance with our study, we suggest D-dimer analysis be performed on plasma samples stored for <48h at room temperature. Our findings indicate that i-CHROME and VIDAS D-dimer measurement methods have remarkably high sensitivity and are safe first-line tests that can be utilized to rule out pulmonary emboli in outcome studies multiple freeze-thaw.


Biotechnology & Biotechnological Equipment | 2016

Comparative evaluation of the Brucella Coombs gel test in laboratory diagnosis of human brucellosis

Mehmet Koroglu; Özlem Aydemir; Tayfur Demiray; Unal Erkorkmaz; Ahmet Ozbek; Mustafa Altindis

ABSTRACT Brucellosis is widespread among humans and animals. Diagnosis of brucellosis mostly depends on serological methods. Serological tests are preferred over time-consuming and hazardous bacterial cultures in routine laboratory practice. However, these tests are somehow challenging due to ‘incomplete/blocking antibodies’ that prevent agglutination. Brucella Coombs gel test (BCGT) is newly developed test that contains Coombs antibodies (anti-human IgG) in gel microtubes and depends on gel centrifugation methods for the serological diagnosis of brucellosis. Here, performance of the BCGT is compared with standard serum tube agglutination (STA), standard serum tube agglutination with Coombs (C-STA) and immune capture agglutination (Brucellacapt). In total, 78 positive samples for study group and 16 samples for the control group were enrolled in the study. The samples were tested at dilutions of 1:40–1:5120. Titres at 1:160 and above were considered positive for brucellosis, whereas those lower than 1:160 were considered negative. Excellent agreement levels were determined between BCGT test and C-STA (κ, 0.894; p < 0.001), and BCGT and Brucellacapt (κ, 0.802; p < 0.001), when the diagnostic titre was accepted as 1:160. BCGT is easy to apply and interpret and provides reliable titre results in less than 2 h. It is also advantageous for screening.


Viral Hepatit Dergisi | 2015

Hepatitis C Prevalence in Different Age Groups; People Over 50 Years of Age May Receive One-Time Testing for Anti-HCV

Özlem Aydemir; Tayfur Demiray; Mehmet Köroğlu; Ihsan Hakki Ciftci; Ahmet Ozbek; Mustafa Altindiş

ÖZET

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