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Dive into the research topics where Cetin Karaca is active.

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Featured researches published by Cetin Karaca.


Pancreas | 2011

Cyst fluid carcinoembryonic antigen is an accurate diagnostic marker of pancreatic mucinous cysts.

Sevdenur Cizginer; Brian G. Turner; A. Reyyan Bilge; Cetin Karaca; Martha B. Pitman; William R. Brugge

Objectives: Endoscopic ultrasound (EUS) may offer a diagnostic tool through the combination of imaging and guided fine-needle aspiration of pancreatic cysts. The purpose of this investigation was to determine the most accurate test for differentiating mucinous from nonmucinous cysts. Methods: The results of EUS imaging, cytology, and cyst fluid biochemical markers were prospectively collected and compared in a large single-center study (776 patients) using histology or malignant cytology as the final diagnostic standard in 198 patients. Results: The mean cyst fluid carcinoembryonic antigen (CEA) was greater in mucinous cysts (4703.0 ng/mL) compared with nonmucinous cysts (25.8 ng/mL) (P = 0.008). When using the optimal cutoff value of 109.9 ng/mL, the CEA was more accurate (86%, receiver operating characteristic area = 0.928) than EUS imaging (48%) and cytology (58%) in predicting a mucinous cyst (P < 0.0001). Malignant cysts had a mean cyst fluid CEA value (2558.2 ng/mL) similar to benign cysts (4700.2 ng/mL). Cytology (75%) more accurately diagnosed malignant cysts than EUS (66%) and CEA (62%) (P < 0.05). Conclusions: Cyst fluid CEA concentration provides a highly accurate test for the diagnosis of a mucinous cyst, but does not distinguish benign from malignant cysts. Cytology is the most accurate test for the diagnosis of a malignant cyst.Abbreviations: EUS - endoscopic ultrasound, CEA - carcinoembryonic antigen, MCN - mucinous cystic neoplasm, IPMN - intraductal papillary mucinous neoplasm


Journal of Hepatology | 2003

Occult HBV infection and YMDD variants in hemodialysis patients with chronic HCV infection.

Fatih Besisik; Cetin Karaca; Filiz Akyuz; Sibel Horosanlı; Derya Onel; Selim Badur; Mehmet Şükrü Sever; Ahmet Danalioglu; Kadir Demir; Sabahattin Kaymakoglu; Yilmaz Cakaloglu; Atilla Ökten

BACKGROUND/AIMS End-stage renal disease patients on chronic hemodialysis are at risk for both hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Although the prevalence is unknown in hemodialysis patients, occult HBV infection is frequent in subjects with chronic HCV infection. We aimed to investigate (1) the prevalence and clinical impact of occult HBV infection in hemodialysis patients with chronic HCV infection, and (2) the frequency of YMDD variants (tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase) in this setting. METHODS Thirty-three anti-HCV and HCV-RNA-positive, HBsAg-negative hemodialysis patients (mean age 36.9+/-10.4 years, 22 male) were admitted to this study. HBV-DNA (Innogenetics kit) and HCV-RNA (Cobas Amplicor HCV kit) were investigated by polymerase chain reaction technique (PCR). YMDD mutation was studied in all HBV-DNA-positive patients by the BOOM method. RESULTS HBV-DNA was detected in 12 of 33 patients (36.4%) by PCR. Their mean age was 33.0+/-9.0 years. Age, dialysis period (years) and biochemical parameters were not significantly different in patients with and without occult HBV infection. YMDD variants were identified in six of 12 (50%) patients with occult HBV infection. CONCLUSIONS Occult HBV infection is frequent in hemodialysis patients with chronic HCV infection. YMDD variants are common in this setting.


Gastrointestinal Endoscopy | 2010

Accuracy of EUS in the evaluation of small gastric subepithelial lesions

Cetin Karaca; Brian G. Turner; Sevdenur Cizginer; David G. Forcione; William R. Brugge

BACKGROUND EUS combined with endoluminal resection techniques is increasingly used to provide a definitive diagnosis of small gastric subepithelial lesions seen on standard upper endoscopy. OBJECTIVE To evaluate the accuracy of EUS in diagnosing small gastric subepithelial lesions by using histology as the criterion standard. DESIGN A retrospective study. SETTING Academic tertiary care center. PATIENTS A total of 22 patients (15 women, mean age 62.2 years) with an endoscopically resected gastric subepithelial lesion were included in this 3-year retrospective study. MAIN OUTCOME MEASUREMENTS The size, echogenicity, the layer of origin, and presumptive diagnosis were determined by EUS. The diagnostic accuracy of EUS was determined by using histology as the criterion standard. RESULTS The mean size of the 22 lesions was 13.6 mm (range 8-20 mm). An endoscopic cap band mucosectomy device was used to resect 16 (72.7%) lesions, whereas 6 (27.3%) were resected with a saline solution-assisted and snare technique. Using histology as a criterion standard, we found that the accuracy of the EUS diagnosis was 10 of 22 (45.5%). EUS alone had an accuracy rate of 30.8% and 66.7%, respectively, in the diagnosis of neoplastic and non-neoplastic lesions. LIMITATIONS A single-center, retrospective analysis. CONCLUSION EUS imaging had a low accuracy rate in the diagnosis of gastric subepithelial lesions, and endoscopic submucosal resection should be performed to provide a histologic diagnosis. Resection of small subepithelial lesions of 20 mm or less can be accomplished en bloc with an endoscopic cap band mucosectomy device.


Journal of Ultrasound in Medicine | 2005

Crohn Disease Activity Evaluated by Doppler Ultrasonography of the Superior Mesenteric Artery and the Affected Small-Bowel Segments

Ensar Yekeler; Ahmet Danalioglu; Behzad Movasseghi; Sabri Yilmaz; Cetin Karaca; Sebahattin Kaymakoglu; Bulent Acunas

To reveal the disease activity in Crohn disease by gray scale and Doppler ultrasonography of the superior mesenteric artery (SMA) and the affected bowel segments.


BJUI | 2006

Selective nuclear factor κ‐B inhibitors, pyrolidium dithiocarbamate and sulfasalazine, prevent the nephrotoxicity induced by gentamicin

Volkan Tugcu; Emin Ozbek; Ali İhsan Taşçı; Eray Kemahli; Adnan Somay; Muzaffer Baş; Cetin Karaca; Tuncay Altug; Mustafa B. Çekmen; Haci K. Özdogan

To investigate the effect of selective nuclear factor κ‐B (NFκ‐B) inhibitors, pyrolidium dithiocarbamate (PD) and sulfasalazine (SZ) on renal tubular necrosis and inducible nitric oxide synthase (iNOS) and NFκ‐B expression induced by gentamicin in rats.


Antimicrobial Agents and Chemotherapy | 2013

Efficacy of Tenofovir in Patients with Lamivudine Failure Is Not Different from That in Nucleoside/Nucleotide Analogue-Naïve Patients with Chronic Hepatitis B

Bulent Baran; Ozlem Mutluay Soyer; Asli Ormeci; Suut Gokturk; Sami Evirgen; Hamza Ugur Bozbey; Filiz Akyuz; Cetin Karaca; Kadir Demir; Fatih Besisik; Derya Onel; Mine Gulluoglu; Selim Badur; Sabahattin Kaymakoglu

ABSTRACT We evaluated the efficacy of tenofovir disoproxil fumarate (TDF) in patients with lamivudine failure (LAM-F) in comparison with that in nucleoside/nucleotide analogue (NA)-naïve patients with chronic hepatitis B (CHB). The criteria for inclusion were being NA naïve or having previous LAM-F and receiving TDF therapy for at least 6 months. Biochemical and virological tests were performed at the baseline, at 3-month intervals in the first year, and every 6 months thereafter. The primary outcome measure for efficacy was a complete virological response (CVR), defined as an HBV DNA level of <20 IU/ml. CVR rates were calculated by Kaplan-Meier analysis, and a multivariate Cox proportional-hazard model was generated in order to find predictive factors independently associated with the time to a CVR. We included 197 patients in the study (136 males; mean age, 43 ± 12 years; 105 patients were NA naïve). Sixty-five patients had hepatitis B e antigen (HBeAg)-positive CHB. The median duration of TDF treatment was 29 (range, 6 to 52) months. Seventy-one patients (77%) in the LAM-F group were treated with TDF add-on therapy. The CVR rates of the NA-naïve and LAM-F groups were comparable in HBeAg-negative (94% versus 96% at month 36, P = 0.10) and HBeAg-positive patients (67% versus 83% at month 36, P = 0.48). According to the multivariate Cox regression model, only HBeAg positivity (hazard ratio [HR], 0.39; 95% confidence interval [CI], 0.26 to 0.59; P < 0.001) and a high baseline HBV DNA level (HR, 0.44; 95% CI, 0.29 to 0.67; P < 0.001) had a significant influence on the time to a CVR. The similar cumulative CVR rates during the follow-up show that TDF has comparable efficacy in lamivudine-experienced and NA-naïve patients, and the presence of resistance mutations did not alter the response rates.


Journal of Endourology | 2008

Protective Effect of a Potent Antioxidant, Pomegranate Juice, in the Kidney of Rats with Nephrolithiasis Induced by Ethylene Glycol

Volkan Tugcu; Eray Kemahli; Emin Ozbek; Yasar Volkan Arinci; Mehmet Uhri; Pelin Erturkuner; Gokhan Metin; Ismail Seckin; Cetin Karaca; Nursen Ipekoglu; Tuncay Altug; Mustafa Cekmen; Ali Ihsan Tasci

PURPOSE We aimed to study the protective effects of pomegranate juice (PJ) on ethylene glycol (EG)-induced crystal deposition in renal tubules, renal toxicity, and inducible nitric oxide synthase (iNOS) and nuclear factor-kappaB activities in rat kidneys. MATERIALS AND METHODS Fifty-six rats were divided into four equal groups: Control, EG, EG + 50 microL PJ/d (PJ50), and EG + 100 microL PJ/d (PJ100). Rats were sacrified on days 10 and 45. Tissue sections were evaluated under light and polarized microscopy for the presence and degree of crystal deposition and toxicity in the kidneys. Crude extracts of the cortex were used to determine reduced gluthatione (GSH), nitric oxide (NO), and malondialdehyde (MDA) levels. RESULTS In the EG group, crystal depositions were more evident and mild crystalization was observed in proximal tubules on day 10; severe crystalization and granulovacuolar epithelial cell degeneration were observed on day 45. There was limited or no crystal formation in the EG + PJ-given groups. There were completely normal renal and tubular structures in the control group. There was no significant difference between the four groups in serum levels of sodium, potassium, blood urea nitrogen, and creatinine in any sampling time. Hyperoxaluria, a marked increase in MDA and NO levels, and decrease of GSH were observed in the EG-given groups compared with the others. There were marked iNOS and p65 expressions in only the EG-given rats compared with control and PJ groups, immunohistochemically. CONCLUSION This experiment shows the protective effect of PJ in the EG-induced crystal depositions in renal tubules.


Antimicrobial Agents and Chemotherapy | 2005

Alpha Interferon and Ribavirin Combination Therapy of Chronic Hepatitis D

Sabahattin Kaymakoglu; Cetin Karaca; Kadir Demir; Sule Poturoglu; Ahmet Danalioglu; Selim Badur; Mürvet Bozaci; Fatih Besisik; Yilmaz Cakaloglu; Atilla Ökten

ABSTRACT The success of alpha interferon (IFN-α) monotherapy for the treatment of chronic hepatitis D is very limited. In this study, the efficacy of IFN-α and ribavirin combination therapy for chronic hepatitis D was investigated. Nineteen patients (15 males; mean age ± standard deviation, 36.8 ± 12.8 years) with chronic hepatitis D who were treated with IFN-α2b (10 million U, three times/week, subcutaneously) and ribavirin (1,000 to 1,200 mg/day, orally) for 24 months were studied. All patients had compensated liver disease (15 were precirrhotic), elevated transaminase levels, and hepatitis D virus RNA positivity at baseline. Genotypic analyses revealed hepatitis D virus genotype I and hepatitis B virus genotype D. All patients completed the 24 months of treatment and at least 6 months (7 to 19 months) of a follow-up period. Biochemical responses were observed in eight patients (42.1%) at the end of treatment and in seven patients (36.8%) at the end of follow-up. Eight patients (42.1%) at the end of treatment and four patients (21%) at the end of follow-up had virological responses. In conclusion, combination treatment of IFN-α and ribavirin for chronic hepatitis D is not able to induce virological responses at a sufficient rate, despite its partial effectiveness in improving biochemical responses, and is not superior to IFN-α monotherapy.


Digestive Diseases and Sciences | 2006

Risk factors for the transmission of hepatitis C virus infection in the Turkish population.

Cetin Karaca; Yilmaz Cakaloglu; Kadir Demir; Sadakat Özdil; Sabahattin Kaymakoglu; Selim Badur; Atilla Ökten

The risk factors for the transmission of hepatitis C virus (HCV) infection varies substantially between countries and geographic regions. The aim of this investigation was to determine the risk factors which may be involved in the transmission of HCV infection in the Turkish population. This study included patients who were admitted to the Department of Gastroenterohepatology, Istanbul Medical Faculty, Istanbul University, between 1996 and 2002 and found to be anti-HCV positive during hospitalization or during follow-up as outpatients. All patients were asked about risk factors for HCV transmission including transfusion, history of operation, hospitalization, hemodialysis, intravenous drug use, suspected sexual contact, tattooing, acupuncture, dental procedures, manicure and pedicure, blood brotherhood rituals, perinatal risk factors, common circumcision rituals, and history of abortion. In our study, total of 320 patients with anti-HCV seropositivity were involved. The numbers and percentages of male and female patients were 139 (43.4%) and 181 (56.6%), respectively. The mean age of the patients was 49.7± 12.4 years (range: 18–73 years). HCV-RNA was found to be positive in 297 (92.8%) patients. The most common risk factor was a history of surgery (305; 98%), and the second most common was blood transfusion (123; 39.7%). The numbers and percentages of patients for the other risk factors were as follows: dental procedure, 86 (27.5%); abortion, 66 (21.2%); long-term hospitalization, 37 (11.6%); hemodialysis, 31 (10%); history of jaundice, 15 (4.6%); history of intravenous drug abuse, 10 (3.1%); history of suspected sexual contact, 5 (1.5%); history of manicure and pedicure, 4 (1.2%); history of occupational transmission, 3 (0.9%); history of tattooing, 2 (0.6%); history of acupuncture, 2 (0.6%); circumcision in a common circumcision ritual, 1 (0.3%); and percutaneous needle puncture, 1 (0.3%). None of the patients had a history of blood brotherhood ritual or perinatal transmission. Only one risk factor was detected in 73 (22.8%) patients, two risk factors were detected in 122 (38.2%) patients, three risk factors were detected in 78 (24.5%) patients, and four risk factors were detected in 39 (12.2%) patients, however, in 8 (1.6%) patients no risk factors could be found. In Turkey, the most common risk factor for the transmission of HCV infection is surgery, which can be preventable.


Journal of International Medical Research | 2004

Intra-articular Injection of Tenoxicam in Rats: Assessment of the Local Effects on the Articular Cartilage and Synovium

H Ozyuvaci; B Bilgic; E Ozyuvaci; A Altan; T Altug; Cetin Karaca

This study investigated the possible local adverse effects of intra-articular administration of tenoxicam in the rat knee joint. A total of 50 rats were given 0.25 ml of a standard preparation of tenoxicam by injection into the right knee joint and 0.25 ml of 0.9% saline solution by injection into the left knee joint as a control. Groups of 10 rats were killed 24 h, 48 h, 7 days, 14 days and 21 days after tenoxicam administration. Two rats were sham operated; one was killed on the first day and the other on the second day after this procedure. All the joints were prepared and sectioned for histological examination. Tissue loss and oedema were observed in the specimens obtained 24 h and 48 h after treatment with tenoxicam. No pathological changes were observed in the 7-day, 14-day and 21-day specimens, or in the control joints. Caution should be exercised when using intra-articular tenoxicam for postoperative analgesia.

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