Omer Cetin

The evaluation of oxidative stress in patients with chronic renal failure

BACKGROUND Free radical-mediated changes are thought to be involved with atherosclerosis in patients with chronic renal failure. METHODS The protein carbonyl and malondialdehyde (MDA) levels in serum as the markers of radical-induced protein and lipid oxidations were measured in chronic renal failure patients. RESULTS Serum carbonyl and MDA levels in both hemodialysis and peritoneal dialysis patients were not found to be different as compared with healthy subjects. In both patient groups, the approximately twofold increment in total antioxidant activity (ferric reducing/antioxidant power; FRAP) and uric acid values in serum were found. The high uric acid levels in both patient groups might be partly responsible for the increment in FRAP values. In addition, all patients received multivitamin preparations including ascorbate, which was also a major antioxidant in serum. CONCLUSIONS Our data suggest that oxidative stress does not become the major threat for patients with chronic renal failure. The increment in endogenous and exogenous antioxidant capacities in serum might be thought to prevent any possible radical-induced damage in patients with chronic renal failure. In addition, the increased nitric oxide (NO) levels especially in hemodialysis patients might likely favor an antioxidant effect.

Effects of Electrical Stimulation on Meat Quality of Lamb and Goat Meat

Effect of various voltage of electrical stimulation (ES) on meat quality of lamb and goat was investigated by using a total of 36 animals at 3–5 years old. Constant 50 Hz frequency and 50, 100, and 250 V, 90 sec of ES were administered to 1/2 carcasses and were examined according their textural, physicochemical, and sensorial characteristics. ES decreased the pH values of lamb and goat meat, and accelerated the rigor mortis (P < 0.05). Additionally, ES enhanced the water activity, water-holding capacity, and drip loss of both animals. Shear force varied between lamb and goat meat, and tenderness was improved depending on voltage range used (P < 0.001). ES caused difference in instrumental colour (CIE L ∗, a ∗, b ∗) values of lamb and goat meat compared with the control groups (P < 0.05) during aging period at 4°C. Sensorial characteristics were also improved with various levels of ES treatments. In conclusion, ES had positive effects on meat quality of lamb and goat, in contrast to undesirable consumer preferences.

Determination of Mould and Aflatoxin Contamination in Tarhana, a Turkish Fermented Food

Tarhana is a popular traditional Turkish cereal-based fermented food product mainly produced at home or at home-scale level. Some certain mould species can grow even at low moisture and pH values and produce aflatoxins in food. This study was conducted to determine aflatoksin levels in tarhana. For this purpose, a total of 138 tarhana powder samples were collected from bazaars in Istanbul and analyzed for aflatoxins, mould contamination, and some physco-chemical parameters. As a result, 32 out of 138 tarhana samples (23.2%) were found to be contaminated with aflatoxins in the range of 0.7–16.8 μg/kg, whereas 29 samples contained Aflatoxin B1 (AFB1) ranging from 0.2–13.2 μg/kg. All samples (100%) contaminated with moulds in the range of 1.4 × 101 –5.8 × 107cfu/g. The average pH, moisture and aw results were detected as 3.82, 12.71%, and 0.695, respectively.

Effect of lemon juice on the survival of Salmonella Enteritidis and Escherichia coli in cig kofte (raw meatball)

Purpose – The purpose of this study is to investigate the effect of lemon juice on the survival of Salmonella Enteritidis and Escherichia coli in cig kofte (raw meatball).Design/methodology/approach – Cig kofte samples were inoculated one by one with both bacteria at high inoculum levels and were treated with different doses of fresh lemon juice (2, 5, 10 and 15 ml) for 10 seconds, 30 seconds, and 1, 5, 15, 30 and 60 minutes.Findings – Treatments of lemon juice for different exposure times caused reduction ranging between 0.1 and 1.7 log CFU/g for Salmonella Enteritidis and 0.1 and 2.1 log CFU/g for E.coli. Results showed that lemon juice caused slight decrease in Salmonella Enteritidis and E.coli as an immediate inhibitor, but this effect increased with concentration and time.Originality/value – This is a research study to provide information on the effectiveness of lemon juice which is squeezed generally before eating cig kofte, on the presence of the surface flora to strengthen the hygienic quality of ...

Presence and antibiotic susceptibility patterns of contagious mastitis agents (Staphylococcus aureus and Streptococcus agalactiae) isolated from milks of dairy cows with subclinical mastitis

Serkan İKİZ, Beren BAŞARAN, Enver Barış BİNGÖL*, Ömer ÇETİN, Güven KAŞIKÇI, Naciye Yakut ÖZGÜR, Melih UÇMAK, Özge YILMAZ, Mehmet Can GÜNDÜZ, Ahmet SABUNCU Department of Microbiology, Faculty of Veterinary Medicine, İstanbul University, Avcılar, İstanbul, Turkey Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, İstanbul University, Avcılar, İstanbul, Turkey Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, İstanbul University, Avcılar, İstanbul, Turkey

Low complexity channel estimation for 3GPP LTE downlink MIMO OFDM systems

Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is a promising technique for reaching high data rates targeted in the 3rd Generation Partnership Project - Long Term Evolution (3GPP-LTE). MIMO-OFDM channel estimation schemes play a very important role on achieving this aim. However, the complexity of the estimators increases exponentially due to the structure of the MIMO systems. This causes an increase in the computational burden of the transceivers. As a result, the complexity of the channel estimators is becoming an important issue in real world MIMO-OFDM applications. In this paper, the performance of the low complexity Minimum Mean Square Error (MMSE) channel estimator scheme based on Karhunen-Loéve (KL) series expansion coefficients for the 3GPP-LTE Downlink MIMO-OFDM systems is examined. System level simulations are accomplished to compare the performances of the estimators under the spatially correlated channel coefficient variations.

Microbiological quality of ice and ice machines used in food establishments

The ice used in the food industry has to be safe and the water used in ice production should have the quality of drinking water. The consumption of contaminated ice directly or indirectly may be a vehicle for transmission of pathogenic bacteria to humans producing outbreaks of gastrointestinal diseases. The objective of this study was to monitor the microbiological quality of ice, the water used in producing ice and the hygienic conditions of ice making machines in various food enterprises. Escherichia coli was detected in seven (6.7%) ice and 23 (21.9%) ice chest samples whereas E. coli was negative in all examined water samples. Psychrophilic bacteria were detected in 83 (79.0%) of 105 ice chest and in 68 (64.7%) of 105 ice samples, whereas Enterococci were detected only in 13 (12.4%) ice samples. Coliforms were detected in 13 (12.4%) water, 71 (67.6%) ice chest and 54 (51.4%) ice samples. In order to improve the microbiological quality of ice, the maintenance, cleaning and disinfecting of ice machines should be carried out effectively and periodically. Also, high quality water should be used for ice production.

The prevalence of Clostridium difficile in cattle and sheep carcasses and the antibiotic susceptibility of isolates

Clostridium difficile is an anaerobic, spore forming, rod shaped bacterium frequently isolated from butchery animals in recent years. The aim of this study is to evaluate the presence of C. difficile (especially ribotype 027 and 078) in cattle and sheep carcasses and to investigate the antibiotic susceptibility of isolates. The bacterium was isolated in 83 out of 247 (33.6%) cattle and 78 out of 308 (25.3%) sheep carcass samples. 15/83 (18.1%) cattle and 6/78 (7.7%) sheep isolates were identified as ribotype 027, whereas the other hypervirulent isolate ribotype 078 could not be detected among the analysed samples. Almost all isolates were susceptible to amoxicillin-clavulanic acid (98.8%), vancomycin (96.9%) and tetracycline (97.5%), whereas resistant to cefotaxim (97.5%) and imipenem (87.0%). In conclusion, the results demonstrate the presence of toxigenic C. difficile isolates in cattle and sheep carcasses on the slaughter line. As a result, the results of this study demonstrate the presence of toxigenic C. difficile isolates in cattle and sheep carcasses on the slaughter line.