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Öğe Evaluation of the effects of precipitation and flow characteristics on suspended sediment transport in mountain-type Mediterranean climate; Korkuteli Stream sample, Antalya, Turkey(Springer Science and Business Media Deutschland GmbH, 2021) Çakmak, Seçkin; Demir, Tuncer; Canpolat, Ergin; Aytaç, Ahmet SerdarAmount and type of suspended sediments in streams can change over seasonal timescales and during high-flow events. The dynamics of the suspended sediment in the streams and rivers of the Mediterranean region of Turkey are not yet fully understood, as studies are limited. In this study, it is aimed to analyze the seasonal variation of suspended sediment transported over 12 months in the Korkuteli Stream to reveal the relationship between precipitation, flow, and suspended sediment. The water level of the stream recorded automatically every 10 min using an Immersion Type Level Transmitter and the water velocity were measured with a Universal Current Meter. The flow rate was estimated with a rating curve produced from the water velocity and cross-sectional data. US-DH48 depth integration sampler was used to take the suspended sediment samples and these samples analyzed in the laboratory. A significant relationship was found between flow and suspended sediment (R2: 0.97). The amount of suspended sediment increased significantly during high flow periods. Although most of the precipitation occur in winter months, the amount and rate of suspended sediment increase significantly during the shorter flood period in summer months (e.g., May and June) due to short-term heavy precipitation. During the measurement period, the total amount of transported suspended sediment was calculated as 47246 tons, of which approximately 87% (41106 tons) was transported largely in June. © 2021, Saudi Society for Geosciences.Öğe Expressions of TRPM6 and TRPM7 and histopathological evaluation of tissues in ischemia reperfusion performed rats(Informa Healthcare, 2014) Dokuyucu, Recep; Gogebakan, Bulent; Yumrutas, Onder; Bozgeyik, Ibrahim; Gokce, Hasan; Demir, TuncerThere is very little work on the expression of TRPM6/7 in ischemia reperfusion models. In previous studies, after ischemia, reperfusion had been kept limited to 24 h, yet in our study, expressions of these channels were elucidated after its modification to 48 h to establish what kind of changes renal tissues undergo. For the current study, 20 Wistar albino rats were divided into two groups equally. Group I: control group, Group II = I/R group (60 min ischemia + 48 h reperfusion). For the mRNA analysis, right kidneys of I/R group was used as a reference in order to eliminate genetic differences. The left renal artery (I/R generated part) of I/R area was removed from all rats in the second group. Likewise, normal tissues of right renal artery were removed from all rats. Histopathologic scoring of the tissue samples were achieved semi-quantitatively according to normal tissue composition. Consequently, both TRPM6 and TRPM7 expression levels were decreased in all groups according to control groups, yet results were not counted as significant (p>0.05). Additionally, correlation analysis confirmed these results. Also, I/R performed kidneys had more tissue damage compared to control group. To conclude, our study results suggest that TRPM6/7 expressions may be increased and after 48 h of reperfusion expression levels of these two stored to normal levels. At the same time, damages have occurred in renal tissues after ischemia. These damages were considered to be resulted from the oxidative effects as previously reported.Öğe Investigation of Cytotoxic effects of Oxymetazoline on Lungs in a Rat Mod-el of Rhinitis Medicamentosa(Bentham Science Publ Ltd, 2020) Cengiz, Beyhan; Bostanciklioglu, Mehmet; Demir, Tuncer; Karabulut, Hayriye; Dokuyucu, Recep; Ulasli, MustafaBackground: Rhinitis medicamentosa, also known as 'rebound congestion,' is inflammation of the nasal mucosa caused by the overuse of topical nasal decongestants. Although local decongestants resolve the initial nasal obstruction, the overuse causes rebound obstruction. However, how the overuse of the decongestant causes rhinitis medicamentosa is not known. Objectives: Here, we show the intracellular effects of oxymetazoline, commonly used a local decongestant, on the cell death pathways. We also investigated the antioxidative effects of erdosteine suspension (175 mg/5mL), an antioxidative agent. Methods: Thirty Wistar-albino rats were used to form the rhinitis medicamentosa model. After rhinitis medicamentosa was clinically detected, we removed the whole lungs of animals to perform the molecular analyses of cell death pathways. Results: We found a statistically significant decrease in the expression levels of Atg5 (p=0.021), Atg7 (p=0.013) and Ulk1 (p=0.036) in the oxymetazoline group compared to the control group (p<0.05); however, Caspase 3 expression level was recorded to be significantly increased in the oxymetazoline group, and the expression level of Beclin1 recorded to be substantially increased in the erdosteine group (p=0.001). Conclusion: Based on these grounds, we suggest that vasoconstriction in capillary vessels caused by oxymetazoline could lead to a decrease in the blood supply, which triggers autophagy to ensure cellular homeostasis.Öğe Palosuran Treatment Effective as Bosentan in the Treatment Model of Pulmonary Arterial Hypertension(Springer/Plenum Publishers, 2014) Pehlivan, Yavuz; Dokuyucu, Recep; Demir, Tuncer; Kaplan, Davut Sinan; Koc, Ibrahim; Orkmez, Mustafa; Turkbeyler, Ibrahim HalilPulmonary arterial hypertension (PAH) is a progressive and fatal disorder that any valuable advance in the management of diseases has crucial importance. The present study aimed to compare the Endothelin1 (ET1) inhibitor bosentan which is regarded as standard therapy with different dose regimens of palosuran which is urotensin-II (UII) inhibitor and explore the discrepancy for mean pulmonary arterial pressure (mPAP), UII, ET1 levels, and pulmonary vascular pathology. Seventy rats were randomly divided into seven groups of ten animals each: group 1 (control group) received the vehicle subcutaneously, instead of monocrotaline (MCT) and vehicle; group 2 (MCT group) received subcutaneous MCT and vehicle; and group 3 (MCT + palosuran 30 mg) received subcutaneous MCT and palosuran. Other groups consist of group 4 (MCT + palosuran 100 mg), group 5 (MCT + bosentan 30 mg), group 6 (MCT + bosentan 100 mg), and group 7 (combination therapy). Serum ET1, UII, mPAP levels, and pulmonary arteriolar pathology of different diameter vessels of all groups have been measured and recorded. The ET1 and UII levels of untreated rats (group 2) were significantly higher than the other groups (p < 0.05). Moreover, mPAP levels of group 2 were significantly higher than the other groups (p = 0.001). Finally, 50-125-mu m diameter of arteriole wall thickness was found to be significantly thicker in monocrotaline group compared to groups 4 and 6 (p < 0.001). Statistical differences of wall thickness/diameter ratios of arteries and arterioles larger than 125 was found to be significant between group 5, group 6, and the control group (p < 0.001). UII inhibitor is at least as effective as standard therapy bosentan. Findings of this study consolidate that palosuran could be a new future promising therapeutic option in PAH.Öğe The role of hepcidin and its related genes (BMP6, GDF-15, and HJV) in rats exposed to ischemia and reperfusion(2014) Dokuyucu, Recep; Demir, Tuncer; Yumrutaş, Önder; Erbağcı, Ayşe Binnur; Örkmez, Mustafa; Bahar, Abdulkadir Yasir; Bayraktar, Recep; Bozgeyik, İbrahim; Kaplan, Davut Sinan; Cengiz, Beyhan; Bağcı, CahitBackground/aim: To determine the roles of hepcidin and its related genes in a renal ischemia/reperfusion model. Materials and methods: A total of 20 Wistar albino rats were equally divided into 2 groups: Group I was the control group and Group II was the ischemia and reperfusion (I/R) group (60 min of ischemia + 48 h of reperfusion). I/R was performed on the left kidneys of these rats and then the I/R-treated kidneys were removed. The levels of serum biochemical markers were evaluated after renal I/R. The expression levels of hepcidin-linked genes [growth differentiation factor 15 (GDF-15), bone morphogenetic protein 6 (BMP6), and hemojuvelin (HJV)] were also measured by RT-PCR technique. In addition, the tissues were evaluated histopathologically. Results: No significant association was found between renal dysfunction and I/R when compared to biochemical parameters (P > 0.05). However, differences in platelet values were statistically significant (P < 0.05). Expression levels of GDF-15, BMP6, and HJV genes increased, but this increase was not statistically significant. In addition, histopathological evaluation was performed using hematoxylin and eosin stain. This showed a significant relationship between the control group and I/R group for ischemic and nonischemic kidney scoring. Conclusion: Hepcidin and BMP6, HJV, and GDF-15 should be taken into account when investigating the process of I/R.
