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    Öğe
    Effects of Cooling Rate on Membrane Integrity and Motility Parameters of Cryopreserved Ram Spermatozoa
    (Kafkas Univ, Veteriner Fakultesi Dergisi, 2015) Demir, Kamber; Bakirer Ozturk, Gul; Cirit, Umit; Bozkurt, H. Hakan; Aktas, Abit; Birler, Sema; Ak, Kemal
    In this study we aimed to determinate the effects of three different cooling rates from +26 degrees C to +5 degrees C at (0.3 degrees C/min 0.6 degrees C/min and 0.9 degrees C/min) on spermatologic and ultrastructure properties of ram semen. For this purpose semen from 6 rams was collected by electroejaculator and was pooled in a +26 degrees C waterbath. Pooled semen was diluated with tris based extender and divided into three equal parts according cooling rates (0.3 degrees C/min., 0.6 degrees C/min. and 0.9 degrees C/min). Cooled semen was reextended with extender B +5 degrees C in the second step. Diluated samples were equilibrated for 1 h and then were loaded in 0.25 mL straws and freezed in liquid nitrogen vapor. After each freezing stage semen was evaluated motility with computer-assisted semen analysis (CASA). Electron microscobic evaluation was done for pooled and chilled samples. It has been observed that 0.3 degrees C/min. cooled group had meaningfully higher values of motility and progressive motility at +5 degrees C after equilibration and post-thaw stages when compared with the 0.9 degrees C/min. group (P<0.05). When compared to the 0.6 degrees C/min., the 0.3 degrees C/min. cooled group had higher total motility values at after cooling to +5 degrees C (P<0.05), equilibration (P<0.05) and post thaw stages (P>0.05) and had higher progressive motility at after cooling to + 5 degrees C (P<0.05), equilibration (P>0.05) and post-thaw stage (P<0.05). The TEM evaluation showed that at cooling to the +5 degrees C increases the total damaged spermatozoa in all groups (P<0.05). In conclusion, cooling the ram semen to +5 degrees C with a rate above 0.3 degrees C/min. affected negatively the spermatological characteristics. Reaching the cooling rates of 0.6 and 0.9 degrees C/min. increasingly deteriorated the post-thaw motility and progressive motility values. Also, low temperature related to ultrastructural damage was observed at the first dilution step and localized at different regions of the sperm head depends upon the processes and cooling rates.
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    Öğe
    The role of oxidative stress and inflammatory response in high-fat diet induced peripheral neuropathy
    (Elsevier Science Bv, 2014) Ozay, Rafet; Uzar, Ertugrul; Aktas, Abit; Uyar, Mehtap Erkmen; Gurer, Bora; Evliyaoglu, Osman; Cetinalp, Nuri Eralp
    Objective: Earlier studies suggest that high-calorie diet is an important risk factor for neuronal damage resulting from oxidative stress of lipid metabolism. In our experimental study of rats under high-fat diet, oxidative stress markers and axonal degeneration parameters were used to observe the sciatic nerve neuropathy. The aim of this study is to evaluate the pathophysiology of neuropathy induced by high-fat diet. Methods: A total of 14 male rats (Wistar albino) were randomly divided into two experimental groups as follows; control group (n = 7) and the model group (n = 7); while control group was fed with standard diet; where the model group was fed with a high-fat diet for 12 weeks. At the end of 12 weeks, the lipid profile and blood glucose levels, interleukin-1 beta (IL-1), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and transforming growth factor-beta (TGF-beta) levels were studied. Tissue malondialdehyde (MDA), nitric oxide (NO) levels and super-oxide dismutase (SOD), paraoxonase-1 (PON-1) and glutathione peroxidase (GPx) activities were studied. The distal blocks of the left sciatic nerves were evaluated for histomorphological analysis (including mean axon area, axon numbers, nerve fiber diameters, axon diameters, and thickness of myelin sheets). Results: Body weights, serum glucose and high-density lipoprotein (HDL) levels of rats were found not statistically significantly different compared between the model and the control groups (p > 0.05). Serum cholesterol, triglyceride, TGF-beta and TNF-alpha levels were significantly higher in the model group when compared with the control group (p < 0.05). IL-1 and IL-6 levels were not statistically significantly different compared between the model group and the control group (p > 0.05). The MDA and NO levels and the SOD and GPx activities of the sciatic nerves in model group were statistically significantly higher than the control group (p < 0.05). In addition, the activities of PON-1 were statistically significantly lower in the model group when compared with the control group (p < 0.05). The difference in the total number of myelinated axons between the control group and the model group was not statistically significant (p > 0.05). The nerve fiber diameter and the thickness of the myelin sheet were statistically significantly lower in the model group when compared with the control group (p < 0.05). The axon diameter and area were significantly decreased in the model group when compared with the control group (p < 0.05). Conclusion: Our results support that dyslipidemia is an independent risk factor for the development of neuropathy. In addition, we postulated that oxidative stress and inflammatory response may play an important role in the pathogenesis of high-fat diet induced neuropathy. (C) 2014 Elsevier B.V. All rights reserved.