AYÇA DOĞAN1*, GALİP SİYAKUŞ2, FERİDE SEVERCAN3

AYÇA DOĞAN^1*, GALİP SİYAKU޲, FERİDE SEVERCAN³

Food irradiation is a physical process as food preservation method. This process is currently approved in over 40 different countries as a means of enhancing the hygenic quality, extending shelf-life, reducing the incidence of food-borne diseases, and eliminating quarantine pests. Its ultimate goal is the prevention of adverse changes by undesirable microbial or biochemical action, which provides better preserving quality.

Fourier transform infrared (FT-IR) spectroscopy can be considered as a potentially effective tool for quality control applications in the food industry. In this study, 1.5kGy and 10kGy gamma irradiated hazelnut tissue were examined in comparison to the control groups at molecular level by FTIR spectroscopy. For this purpose, two different methods (tissue level and homogenate membrane level) were used.

In tissue level studies, the FTIR spectra revealed differences in the signal intensity values and their ratios between the irradiated and control tissues. At 1.5kGy irradiated tissues, an increase in the total lipid content, especially in the level of fatty acid, differences in the packing of ester groups, a decrease in the nucleic acid content were seen. No significant change was observed in protein bands. In 10kGy irradiated tissue, a decrease in the total lipid content, and an increase in dehydrated phosphate group of nucleic acids were also observed.

In the homogenate membrane method, all the observed interactions were also valid and in agreement with the results of tissue level studies. Some additional information was obtained from various FTIR spectral bands. For example, free C=O groups and hydrogen bonds were seen in the lipid parts causing a change in the polarity of the lipid. Moreover, the structure of cellulose changed in 10kGy irradiated tissue.

Thus, FTIR spectroscopy appears to be useful to rapidly investigate the structural and conformational alterations induced by -irradiation in hazelnut.

*Present adress: Kocaeli University Hereke Ömer İsmet Uzunyol M.Y.O. Hereke / Kocaeli

P296

A COMPARATIVE STUDY ON EFFECTS OF SODIUM SELENITE IN ALTERED ANTIOXIDANT DEFENCES OF HEART AND LIVER IN DIABETES

N. Nuray Ulusu¹, N. Leyla Acan¹, Belma Turan<sup>2

1</sup>Department of Biochemistry, Faculty of Medicine, Hacettepe University, and ²Department of Biophysics, Faculty of Medicine, Ankara University, 06100, Ankara, Turkey.

There is substantial evidence that oxidative stress occurs during the course of diabetes Among the antioxidant protections, it has been shown that selenium has some beneficial effects on diabetic dysfunctions. The present study was aimed to investigate and compare the effects of sodium selenite treatment on antioxidant defence system and ultrastructure of liver and heart tissues of streptozotocin (STZ)-induced diabetic rats. Sodium selenite (5 mol/kg/day) treatment was applied to the diabetic rats (STZ, 50 mg/kg body weight) for four weeks.

Treatment of the diabetic animals with sodium selenite caused an increase in the GSH levels and decrease in glucose-6-phosphate dehydrogenase activities in both heart and liver tissues of the diabetic rats significantly (p<0.05). Glutathione reductase, glutathione peroxidase and glutathione S-transferase activities were significantly (p<0.05) increased in the heart tissues of the diabetic rats while they were decreased in the liver tissues of the same rats. Sodium selenite treatment significantly (p<0.05) reversed these parameters to the normal levels while slightly but significantly decreased the blood glucose level with no effect on the reduced plasma insulin and selenium levels. Electron microscopic morphometry of diabetic heart and liver tissues revealed typical diabetic alterations consisting an increase in collagen content, myofibrillary degeneration, swollen mitochondria and dilatation in the endoplasmic reticulum. Sodium selenite treatment could prevent the loss of myofibrills and reduction of myocyte diameter. Alterations of the discus intercalaris, degenerations seen in myofilaments and Z-lines, and decreased numbers of mitochondria were reversed by this treatment.

P297

INVESTİGATİON OF THE PEPTİDE SECONDARY METBOLİTES PRODUCED BY MYCOBACTERİUM PHLEİ

Bağnu Orhan¹, Esra Büber¹, Zeynep Sarıbaş², Selçuk Keskin³ Meral Özalp⁴, Alpaslan Alp², Haluk Özen³, N. Leyla Açan¹

Under stress, many microorganisms produce secondary metabolites which have specialized functions not related to intermediary metabolism. Apart from their physiological functions these secondary metabolites have several pharmacological activities to be consumed as antibiotics, chemotherateutics, pesticides, immunosuppressive, etc. Strains of mycobacteria produce secondary metabolites with a peptide structure such as exochelin and mycobactin. The aim of this study is to isolate the peptide secondary metabolites produced by mycobacteria and investigate their biological activities. Mycobacterium phlei is selected for this purpose since this strain is not a recognized pathogen for mammals. Mycobacterium phlei is grown in Middlebrook 7H9 broth, under stressed conditions. The cells were removed by centrifugation at 27000xg and the supernatant was brought to 85% ammonium sulphate saturation. The precipitate was dissolved in minimal concentration of 50 mM potassium phosphate buffer, pH 7.0, and dialyzed against the same buffer. After acetone extraction and concentration of the samples, antifungal and antibacterial activities were investigated by microbroth dilution test. MIC values for several Candida species were 42.8 μg/ml. MIC values for Escherichia coli and Enteroccus faecalis were 21.4 μg/ml Staphylococcus aureus and Pseudomonas aeruginosa were 10.9 μg/ml. The work in further purification of the metabolites and the elucidation of the structure that cause antimicrobial effects are under study.

This work is a part of the project (03G31) supported by Hacettepe University Research Unit.

P298

Background: Physical activity has been suggested to be one of the determinants of bone turnover and to prevent age-related bone loss. To examine this we measured the serum levels of osteocalcin, alkaline phosphatase, acid phosphatase, phosphorus, calcium and parathyroid hormone as indices of bone metabolism in the middle-aged master athletes, recreational athletes and sedentary controls. Because the role of long term exercise in bone metabolism is unclear, the aim of this study was to clarify the association between long-term physical training and biochemical markers without mineral density assessment.

Methods: Twelve male master athletes (MA), 12 male recreational athletes (RA) (>10 yr), and 12 male sedentary controls (CG) participated in the study. Baseline serum calcium, phosphorus, alkaline phosphatase, and acid phosphatase levels were estimated by a spectrophotometric method in Integra 400 autoanalyzer, and osteocalcin and parathyroid hormone was estimated by a electrochemiluminescence assay by Elecsys 2010, Roche diagnostics, USA.

Results: MA and RA had higher levels of VO_2max, lower percent body fat (p< 0.01) than CG. BMI was lower in MA than RA and CG (p< 0.05), however, BMI was not significantly different between RA and CG. Master athletes had higher serum concentration of osteocalcin (P = 0.014) than the recreational athletes. There was no significant difference among the groups in terms of serum-ALP, calcium, phosporus, and parathyroid hormone values were within normal ranges.

Conclusion: Our study indicates that intensively trained athletes have an indication of higher bone formation as measured by biochemical markers. Intensive training is more useful than moderate training in stimulating osteoblastic proliferation. Nevertheless, well controlled longitudinal research is warranted to define further its clinical implications.

P299

Prostate-specific antigen (PSA) is an important tumor marker in detecting and monitoring prostate cancer. Because the role of exercise in prostate cancer is unclear, the aim of this study was to clarify the association between long-term physical training and serum PSA concentrations in the middle-aged master athletes, recreational athletes and sedentary controls.

Methods: Twelve male master athletes (MA), 12 male recreational athletes (RA) (>10 yr), and 12 male sedentary controls (CG) participated in the study. Baseline serum total PSA and Free PSA levels of the participants were measured by electrochemiluminescence immunoassay. Group baseline comparisons were made using a Kruskal-Wallis test.

Results: MA and RA had higher levels of VO_2max, lower percent body fat (p< 0.01) than CG. BMI was lower in MA than RA and CG (p< 0.05), however, BMI was not significantly different between RA and CG. There was no significant difference among the groups in terms of total and free PSA and the values were within normal ranges (0.0-4.0, 0.03-0.5 ng/ml, respectively). Free/total PSA ratio was lower in MA compared to RA (p<0.05).

Conclusion: Significant differences between both exercise groups and CG in VO_2max, percent body fat, and BMI (except RA vs. CG) suggest that those who engage in a lifestyle of regular endurance exercise have a more desirable metabolic fitness than inactive people. That there was no statistical significance in total and free PSA levels among the three groups, gives the idea that exercise and also different type of exercise alone does not have a role in reducing risk for prostate cancer. Some other factors affecting PSA levels (having health consciousness, i.e. being non-smoker, not taking alcohol and taking a healthy diet) are as important as physical activity. Nevertheless, more research is warranted to define further its clinical implications.

P300

DOES OBESITY ALTER SERUM LIPIDS IN CHILDREN?

¹Cevval ULMAN, ¹Fatma TANELİ, ² Betül ERSOY, ²Dilek YILMAZ, ¹Özlem TUNCER, ¹Zeki ARI, ¹Bekir Sami UYANIK

¹Celal Bayar University, Faculty of Medicine, Dept of Biochemistry, Manisa, Turkey

²Celal Bayar University, Faculty of Medicine, Dept of Pediatrics, Manisa, Turkey

ulman@isbank.net.tr

Obesity is generally accepted as a risk factor for atherogenesis for adults, and it is frequently accompanied by increased serum lipids. To test whether this is also true in children, we conducted a case control study in a group of children in our region.

We assessed the relation between level of obesity and apolipoproteins (Apo A-I, ApoB), Lipoprotein (a) (Lip(a), and serum lipids. The study group 7.5-17.2 years old (mean 12.9yrs), included 21 obese children, and 83 controls (male/female: 53/52). The groups were similar regarding age and sex, but body mass index (BMI) was significantly higher in the obese children.

In the non-obese children, Apo A-I levels positively correlated with total cholesterol, high (HDL) and low-density lipoprotein (LDL) cholesterol, but Apo B levels correlated only with cholesterol and LDL cholesterol. In the obese children, Apo A-I levels correlated only with cholesterol, and ApoB levels positively correlated with cholesterol and LDL cholesterol. Lip (a) levels did not correlate with cholesterol, trigliserid, HDL cholesterol and LDL cholesterol in obese and non-obese children

The Apo A-I, and ApoB levels were not different between obese and non-obese boys, while these were significantly lower in obese girls (p=0.000, p=0.003 respectively). However the Lip(a) and Apo A-I:B ratios were not different between study groups in either sex (p >0.05 ).

Apo A-I, Apo B, and Lip (a) levels did not correlate with the level of obesity (BMI) in obese and non-obese children.

These results suggest that, most of the serum parameters used classically in the assessment of the risk for atherogenesis is not pertinent in childhood. Obesity may not necessarily alter these parameters in childhood, and making prospects for the prevention of early onset atherogenesis in adulthood becomes difficult. Thus, research for new parameters to assess the risk in children is required.