Browsing by Author "Sisman A.R."

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    Relationship between circulating IGF-1 levels and traumatic brain injury-induced hippocampal damage and cognitive dysfunction in immature rats
    (2012) Ozdemir D.; Baykara B.; Aksu I.; Kiray M.; Sisman A.R.; Cetin F.; Dayi A.; Gurpinar T.; Uysal N.; Arda M.N.
    It is well known that traumatic brain injury (TBI) induces the cognitive dysfunction resulting from hippocampal damage. In the present study, we aimed to assess whether the circulating IGF-I levels are associated with cognition and hippocampal damage in 7-day-old rat pups subjected to contusion injury. Hippocampal damage was examined by cresyl violet staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Spatial memory performance was assessed in the Morris water maze. Serum IGF-1 levels decreased in both early and late period of TBI. Decreased levels of serum IGF-1 were correlated with hippocampal neuron loss and spatial memory deficits. Circulating IGF-1 levels may be predictive of cognitive dysfunction resulted from hippocampal damage following traumatic injury in developing brain. Therapy strategies that increase circulating IGF-1 may be highly promising for preventing the unfavorable outcomes of traumatic damage in young children. © 2011 Elsevier Ireland Ltd.
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    Serum IGF-1 levels correlate negatively to liver damage in diabetic rats
    (2013) Aksu I.; Baykara B.; Kiray M.; Gurpinar T.; Sisman A.R.; Ekerbicer N.; Tas A.; Gokdemir-Yazar O.; Uysal N.
    Diabetes and insulin resistance frequently cause liver damage. Diabetes also causes reduction in liver and blood IGF-1 levels. We investigated the relation between liver damage and IGF-1 levels in diabetic rats. Fourteen Wistar albino rats were divided into control and diabetic groups. Diabetes was induced by streptozotocin. Rats were sacrificed for biochemical and histologic examinations 2 weeks after streptozotocin injection. Serum and liver IGF-1 levels were decreased, liver malondialdehyde (MDA) levels were increased, glutathione peroxidase (GPx) enzymes activities were decreased and serum alanine aminotransferase (ALT) levels were increased in diabetic group. Microscopic examination of liver revealed that normal tissue organization was disrupted in streptozotocin-induced diabetic rats. There was a strongly positive correlation between blood glucose levels and liver injury, and blood and liver IGF-1 levels. There was a strongly negative correlation between blood IGF-1 levels and hepatic injury. Our results suggest that reduction of blood IGF-1 levels correlates with hepatic injury and circulating IGF-1 levels may have predictive value for determining hepatic damage that results from diabetes. In addition, circulating IGF-1 levels are correlated with glutathione levels and the oxidative stress status of diabetic rat liver. © 2013 The Biological Stain Commission.
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    A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers
    (Walter de Gruyter GmbH, 2014) Ozarda Y.; Ichihara K.; Aslan D.; Aybek H.; Ari Z.; Taneli F.; Coker C.; Akan P.; Sisman A.R.; Bahceci O.; Sezgin N.; Demir M.; Yucel G.; Akbas H.; Ozdem S.; Polat G.; Erbagci A.B.; Orkmez M.; Mete N.; Evliyaoglu O.; Kiyici A.; Vatansev H.; Ozturk B.; Yucel D.; Kayaalp D.; Dogan K.; Pinar A.; Gurbilek M.; Cetinkaya C.D.; Akin O.; Serdar M.; Kurt I.; Erdinc S.; Kadicesme O.; Ilhan N.; Atali D.S.; Bakan E.; Polat H.; Noyan T.; Can M.; Bedir A.; Okuyucu A.; Deger O.; Agac S.; Ademoglu E.; Kaya A.; Nogay T.; Eren N.; Dirican M.; Tuncer G.; Aykus M.; Gunes Y.; Ozmen S.U.; Kawano R.; Tezcan S.; Demirpence O.; Degirmen E.
    Background: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. Methods: Blood samples were collected nationwide in 28 laboratories from the seven regions (≥400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA). Results: By ANOVA, differences of reference values among seven regions were significant in none of the 25 analytes. Significant sex-related and age-related differences were observed for 10 and seven analytes, respectively. MRA revealed BMI-related changes in results for uric acid, glucose, triglycerides, high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase, and γ-glutamyltransferase. Their RIs were thus derived by applying stricter criteria excluding individuals with BMI >28 kg/m2. Ranges of RIs by non-parametric method were wider than those by parametric method especially for those analytes affected by BMI. Conclusions: With the lack of regional differences and the well-standardized status of test results, the RIs derived from this nationwide study can be used for the entire Turkish population. © by De Gruyter 2014.
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    The effect of 8-week different-intensity walking exercises on serum hepcidin, IL-6, and iron metabolism in pre-menopausal women
    (Akademiai Kiado ZRt., 2017) Buyukyazi G.; Ulman C.; Çelik A.; Çetinkaya C.; Sisman A.R.; Çimrin D.; Dogru Y.; Kaya D.
    Objective: Hepcidin may be an important mediator in exercise-induced iron deficiency. Despite the studies investigating acute exercise effects on hepcidin and markers of iron metabolism, we found no studies examining the chronic effects of walking exercises (WE) on hepcidin and markers of iron metabolism in premenopausal women. The chronic effects of two 8-week different-intensity WE on hepcidin, interleukin 6 (IL-6), and markers of iron metabolism in pre-menopausal women were examined. Methods: Exercise groups (EG) [moderate tempo walking group (MTWG), n = 11; brisk walking group (BWG), n = 11] walked 3 days/week, starting from 30 to 51 min. Control group (CG; n = 8) did not perform any exercises. BWG walked at ∼70%-75%; MTWG at ∼50%-55% of HRRmax. VO2max, hepcidin, IL-6, and iron metabolism markers were determined before and after the intervention. Results: VO2max increased in both EGs, favoring the BWG. Hepcidin increased in the BWG (p < 0.01) and CG (p < 0.05). IL-6 decreased in the BWG and the MTWG (p < 0.05; p < 0.01). While iron, ferritin, transferrin, and transferrin saturation levels did not change in any group, total iron binding capacity (p < 0.05), red blood cells (p < 0.05), and hematocrit (p < 0.01) increased only in the BWG. Conclusion: Both WE types may be useful to prevent inflammation. However, brisk walking is advisable due to the positive changes in VO2max and some iron metabolism parameters, which may contribute to prevent iron deficiency. The increase in hepcidin levels remains unclear and necessitates further studies. © 2017 Akadémiai Kiadó, Budapest.
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    Statins reduce testicular and ocular VEGF: A potential compromise to microcirculation
    (Academic Press Inc., 2018) Ekerbicer N.; Gurpinar T.; Sisman A.R.; Guvendi G.; Camsari U.M.; Uysal N.
    Microcirculation has great importance in eye and testicular tissue and is necessary to have adequate and appropriate amount of angiogenesis. It is known that high levels of Vascular Endothelial Growth Factor (VEGF) trigger uncontrolled angiogenesis, whereas inadequate VEGF can lead to decreased tissue perfusion and oxygenation. The aim of this study was to investigate effects of VEGF in testicular and ocular tissues in both non-diabetic and diabetic rats treated by statin. Atorvastatin (10 mg/kg daily given by orally gavage) was administered for two weeks. Diabetes was induced by streptozotocin, (STZ, 45 mg/kg/ip) in diabetic group's rats. Two weeks later from STZ injection, atorvastatin treatment was initiated in diabetic group. VEGF levels were measured by using ELISA. The VEGF levels were decreased in vitrous, ocular and testicular tissues of all statin-administered rats. In diabetic group VEGF levels were found to be decreased in testicular tissue and increased in ocular tissues. Conclusion: Statin use decreased in VEGF levels of testicular and ocular tissues in diabetic and non-diabetic rats. Statin treatment (anti-VEGF effect) had a protective effect in the development of diabetic retinopathy, yet statins may have a negative impact on tissues that depend on microcirculation by reducing VEGF levels. Further research is needed for statins’ microcellular effects. © 2018 Elsevier Inc.